A Meta-Analysis of the Effect of Preoperative Biliary Stenting on Patients With Obstructive Jaundice

PubMed Central

Sun, Chengyi; Yan, Guirong; Li, Zhiming; Tzeng, Chi-Meng

2014-01-01

Abstract The goal of this study was to systematically review the effects of biliary stenting on postoperative morbidity and mortality of patients with obstructive jaundice. PubMed, Embase, Cochrane Library, and other relevant databases were searched by computer and manually for published and unpublished studies on the impact of preoperative biliary drainage on patients with obstructive jaundice from 2000 to the present day. Two investigators independently selected the studies according to the inclusion and exclusion criteria, extracted the data, and assessed the quality of the selected studies. Meta-analysis was performed to compare postoperative morbidity and mortality of patients between the drainage and nondrainage groups. Compared with the nondrainage group, the overall mortality, overall morbidity, infectious morbidity, incidence of wound infection, intra-abdominal abscess, pancreatic fistulas, bile leak, and delayed gastric emptying in the drainage group were not significantly different. Compared with the nondrainage group, the drainage group had a drainage time of <4 weeks with an increased overall morbidity by 7% to 23%; however, the overall morbidity of the drainage group with a drainage time >4 weeks was not significantly different. Compared with the nondrainage group, the overall mortality of the drainage group using metal stents and plastic stents as internal drainage devices was reduced by 0.5% to 6%, whereas that of the drainage group using plastic stent devices was not significantly different. In summary, preoperative drainage should be applied selectively. The drainage time should be >4 weeks, and metal stents should be used for internal drainage. PMID:25474436

Lymphatic drainage in renal cell carcinoma: back to the basics.

PubMed

Karmali, Riaz J; Suami, Hiroo; Wood, Christopher G; Karam, Jose A

2014-12-01

Lymphatic drainage in renal cell carcinoma (RCC) is unpredictable, however, basic patterns can be observed in cadaveric and sentinel lymph node mapping studies in patients with RCC. The existence of peripheral lymphovenous communications at the level of the renal vein has been shown in mammals but remains unknown in humans. The sentinel lymph node biopsy technique can be safely applied to map lymphatic drainage patterns in patients with RCC. Further standardisation of sentinel node biopsy techniques is required to improve the clinical significance of mapping studies. Understanding lymphatic drainage in RCC may lead to an evidence-based consensus on the surgical management of retroperitoneal lymph nodes. © 2014 The Authors. BJU International © 2014 BJU International.

Advances in drainage: Selected works from the Tenth International Drainage Symposium

USGS Publications Warehouse

Strock, Jeffrey S.; Hay, Christopher; Helmers, Matthew; Nelson, Kelly A.; Sands, Gary R.; Skaggs, R. Wayne; Douglas-Mankin, Kyle R.

2018-01-01

This article introduces a special collection of fourteen articles accepted from among the 140 technical presentations, posters, and meeting papers presented at the 10th International ASABE Drainage Symposium. The symposium continued in the tradition of previous symposia that began in 1965 as a forum for presenting and assessing the progress of drainage research and implementation throughout the world. The articles in this collection address a wide range of topics grouped into five broad categories: (1) crop response, (2) design and management, (3) hydrology and scale, (4) modeling, and (5) water quality. The collection provides valuable information for scientists, engineers, planners, and others working on crop production, water quality, and water quantity issues affected by agricultural drainage. The collection also provides perspectives on the challenges of increasing agricultural production in a changing climate, with ever-greater attention to water quality and quantity concerns that will require integrated technical, economic, and social solutions.

The application of remote sensing technology to the solution of problems in the management of resources in Indiana

NASA Technical Reports Server (NTRS)

Weismiller, R. A.; Mroczynski, R. P. (Principal Investigator)

1978-01-01

The author has identified the following significant results. Of the sampling techniques considered, a combination soil mapping and area sampling offered the most practical method for gathering soils data. Using the dot grid count, a relative percentage composition of soils can be calculated for each spectral class. From these percentages, a legend describing the dominant soils and inclusions can be developed. Interval drainage class seemed to be correlated with magnitude. For every parent material area, the more poorly drained soils had a lower magnitude of reflectance. Soil spectral classes seemed to be predominantly one internal drainage class.

Performance of advanced trauma life support procedures in microgravity

NASA Technical Reports Server (NTRS)

Campbell, Mark R.; Billica, Roger D.; Johnston, Smith L 3rd; Muller, Matthew S.

2002-01-01

BACKGROUND: Medical operations on the International Space Station will emphasize the stabilization and transport of critically injured personnel and so will need to be capable of advanced trauma life support (ATLS). METHODS: We evaluated the ATLS invasive procedures in the microgravity environment of parabolic flight using a porcine animal model. Included in the procedures evaluated were artificial ventilation, intravenous infusion, laceration closure, tracheostomy, Foley catheter drainage, chest tube insertion, peritoneal lavage, and the use of telemedicine methods for procedural direction. RESULTS: Artificial ventilation was performed and appeared to be unaltered from the 1-G environment. Intravenous infusion, laceration closure, percutaneous dilational tracheostomy, and Foley catheter drainage were achieved without difficulty. Chest tube insertion and drainage were performed with no more difficulty than in the 1-G environment due to the ability to restrain patient, operator and supplies. A Heimlich valve and Sorenson drainage system were both used to provide for chest tube drainage collection with minimal equipment, without the risk of atmospheric contamination, and with the capability to auto-transfuse blood drained from a hemothorax. The use of telemedicine in chest tube insertion was demonstrated to be useful and feasible. Peritoneal lavage using a percutaneous technique, although requiring less training to perform, was found to be dangerous in weightlessness due to the additional pressure of the bowel on the anterior abdominal wall creating a high risk of bowel perforation. CONCLUSIONS: The performance of ATLS procedures in microgravity appears to be feasible with the exception of diagnostic peritoneal lavage. Minor modifications to equipment and techniques are required in microgravity to effect surgical drainage in the presence of altered fluid dynamics, to prevent atmospheric contamination, and to provide for the restraint requirements. A parabolic simulation system was developed for equipment and procedure verification, physiological research, and possible crew medical officer training in the future.

Understanding Lymphatic Drainage Pathways of the Ovaries to Predict Sites for Sentinel Nodes in Ovarian Cancer

PubMed Central

Kleppe, Marjolein; Kraima, Anne C.; Kruitwagen, Roy F.P.M.; Van Gorp, Toon; Smit, Noeska N.; van Munsteren, Jacoba C.; DeRuiter, Marco C.

2015-01-01

Objective In ovarian cancer, detection of sentinel nodes is an upcoming procedure. Perioperative determination of the patient’s sentinel node(s) might prevent a radical lymphadenectomy and associated morbidity. It is essential to understand the lymphatic drainage pathways of the ovaries, which are surprisingly up till now poorly investigated, to predict the anatomical regions where sentinel nodes can be found. We aimed to describe the lymphatic drainage pathways of the human ovaries including their compartmental fascia borders. Methods A series of 3 human female fetuses and tissues samples from 1 human cadaveric specimen were studied. Immunohistochemical analysis was performed on paraffin-embedded transverse sections (8 or 10 μm) using antibodies against Lyve-1, S100, and α-smooth muscle actin to identify the lymphatic endothelium, Schwann, and smooth muscle cells, respectively. Three-dimensional reconstructions were created. Results Two major and 1 minor lymphatic drainage pathways from the ovaries were detected. One pathway drained via the proper ligament of the ovaries (ovarian ligament) toward the lymph nodes in the obturator fossa and the internal iliac artery. Another pathway drained the ovaries via the suspensory ligament (infundibulopelvic ligament) toward the para-aortic and paracaval lymph nodes. A third minor pathway drained the ovaries via the round ligament to the inguinal lymph nodes. Lymph vessels draining the fallopian tube all followed the lymphatic drainage pathways of the ovaries. Conclusions The lymphatic drainage pathways of the ovaries invariably run via the suspensory ligament (infundibulopelvic ligament) and the proper ligament of the ovaries (ovarian ligament), as well as through the round ligament of the uterus. Because ovarian cancer might spread lymphogenously via these routes, the sentinel node can be detected in the para-aortic and paracaval regions, obturator fossa and surrounding internal iliac arteries, and inguinal regions. These findings support the strategy of injecting tracers in both ovarian ligaments to identify sentinel nodes. PMID:26397066

Surgery for chronic pancreatitis. Drainage versus resection.

PubMed Central

Proctor, H J; Mendes, O C; Thomas, C G; Herbst, C A

1979-01-01

A retrospective study of 49 patients with chronic obstructive and chronic calcific pancreatitis is presented. All patients were operated upon and underwent either a partial pancreatectomy or internal drainage of the ductal system into a Roux-en-Y loop of jejunum. The criteria for selection of operation are discussed, and the follow-up of the two operative groups is given. In patients selected as described, internal drainage provided better relief of pain and was accomplished with a lower operative mortality and morbidity and with less postoperative pancreatic insufficiency. Images Fig. 1. Fig. 2. Fig. 3. PMID:443918

The Seepage Simulation of Single Hole and Composite Gas Drainage Based on LB Method

NASA Astrophysics Data System (ADS)

Chen, Yanhao; Zhong, Qiu; Gong, Zhenzhao

2018-01-01

Gas drainage is the most effective method to prevent and solve coal mine gas power disasters. It is very important to study the seepage flow law of gas in fissure coal gas. The LB method is a simplified computational model based on micro-scale, especially for the study of seepage problem. Based on fracture seepage mathematical model on the basis of single coal gas drainage, using the LB method during coal gas drainage of gas flow numerical simulation, this paper maps the single-hole drainage gas, symmetric slot and asymmetric slot, the different width of the slot combined drainage area gas flow under working condition of gas cloud of gas pressure, flow path diagram and flow velocity vector diagram, and analyses the influence on gas seepage field under various working conditions, and also discusses effective drainage method of the center hole slot on both sides, and preliminary exploration that is related to the combination of gas drainage has been carried on as well.

[SIMULTANEOUS MEASUREMENT OF INTRAVENTRICULAR AND PARENCHYMAL INTRACRANIAL PRESSURE IN PATIENTS WITH SEVERE TRAUMA BRAIN INJURY].

PubMed

Oshorov, A V; Popugaev, K A; Savin, I A; Potapov, A A

2016-01-01

"Standard" assessment of ICP by measuring liquor ventricular pressure recently questioned. THE OBJECTIVE OF THE STUDY: Compare the values of ventricular and parenchymal ICP against the closure of open liquor drainage and during active CSF drainage. Examined 7 patients with TBI and intracranial hypertension syndrome, GCS 5.6 ± 1.2 points, 4.2 ± age 33 years. Compared parenchymal and ventricular ICP in three time periods: 1--during closure of ventricular drainage, 2--during of the open drains and drainage at the level of 14-15 mmHg, 3--during the period of active drainage. When comparing two methods of measurement used Bland-Altman method. 1. During time period of the closed drainage correlation coefficient was r = 0.83, p < 0.001. Bland-Altman method: the difference of the two measurements is equal to the minimum and 0.7 mm Hg, the standard deviation of 2.02 mm Hg 2. During time period of the open drainage was reduction of the correlation coefficient to r = 0.46, p < 0.01. Bland-Altman method: an increase in the difference of the two measurements to -0.84 mmHg, standard deviation 2.8 mm Hg 3. During time period of the active drainage of cerebrospinal fluid was marked difference between methods of measurement. Bland-Altman method: the difference was 8.64 mm Hg, and a standard deviation of 2.6 mm Hg. 1. During the closure of the ventricular drainage were good correlation between ventricular and parenchymal ICR 2. During open the liquor drainage correlation between the two methods of measuring the intracranial pressure is reduced. 3. During the active CSF drainage correlation between the two methods of measuring intracranial pressure can be completely lost. Under these conditions, CSF pressure is not correctly reflect the ICP 4. For an accurate and continuous measurement of intracranial pressure on the background of the active CSF drainage should be carried out simultaneous parenchymal ICP measurement.

Extension of local front reconstruction method with controlled coalescence model

NASA Astrophysics Data System (ADS)

Rajkotwala, A. H.; Mirsandi, H.; Peters, E. A. J. F.; Baltussen, M. W.; van der Geld, C. W. M.; Kuerten, J. G. M.; Kuipers, J. A. M.

2018-02-01

The physics of droplet collisions involves a wide range of length scales. This poses a challenge to accurately simulate such flows with standard fixed grid methods due to their inability to resolve all relevant scales with an affordable number of computational grid cells. A solution is to couple a fixed grid method with subgrid models that account for microscale effects. In this paper, we improved and extended the Local Front Reconstruction Method (LFRM) with a film drainage model of Zang and Law [Phys. Fluids 23, 042102 (2011)]. The new framework is first validated by (near) head-on collision of two equal tetradecane droplets using experimental film drainage times. When the experimental film drainage times are used, the LFRM method is better in predicting the droplet collisions, especially at high velocity in comparison with other fixed grid methods (i.e., the front tracking method and the coupled level set and volume of fluid method). When the film drainage model is invoked, the method shows a good qualitative match with experiments, but a quantitative correspondence of the predicted film drainage time with the experimental drainage time is not obtained indicating that further development of film drainage model is required. However, it can be safely concluded that the LFRM coupled with film drainage models is much better in predicting the collision dynamics than the traditional methods.

[COMPLICATIONS OF STENTINGOF UPPER URINARY TRACT].

PubMed

Shkodkin, S V; Kogan, M I; Lyubushkin, A V; Miroshnichenko, O V

2015-01-01

Restoring the passage of urine through the upper urinary tract routinely is achieved by installing of external or internal drainage. Due to its objective advantages, internal drainage has been successfully used in surgery of the upper urinary tract. This review outlines the problems associated with the use ofinternal stents, namely difficultyin installation, migration, and reflux and stent obstruction, bacterial colonization of the stent, the development of functional and morphological changes in the drained segment of urinary tract.

[Choledochotomy and the methods for its performance].

PubMed

Guliaev, A V; Dumpe, E P; Krylov, L B; Kriger, A G

1980-10-01

The authors have made 390 operations on ductus choledochus. Indications for choledochotomy were choledocholithiasis, jaundice, cholangitis and others. The ideal choledochotomy was fulfilled in 7,1% of cases as a completion of diagnostic manipulations on the duct. The external drainage of ductus choledochus was performed in peritonitis, severe cholangitis and inflammatory alterations of the hepatoduodenal ligament and in weak senile patients (mortality--11,7%). Multiple stones and great dilatation of the duct (mortality--4,5%) were considered to serve indications for supraduodenal choledochoduodenostomy (38,7%). Papillotomy was made in fixed ampula stones, stenosis of Vater's papilla (18,2%). Lethality in such cases was twice as high as after choledochoduodenostomy (8,5%). The authors believe peritonitis and duodenostasis to be contraindications against the internal drainage of biliary ducts.

Application of BIM Technology in Building Water Supply and Drainage Design

NASA Astrophysics Data System (ADS)

Wei, Tianyun; Chen, Guiqing; Wang, Junde

2017-12-01

Through the application of BIM technology, the idea of building water supply and drainage designers can be related to the model, the various influencing factors to affect water supply and drainage design can be considered more comprehensively. BIM(Building information model) technology assist in improving the design process of building water supply and drainage, promoting the building water supply and drainage planning, enriching the building water supply and drainage design method, improving the water supply and drainage system design level and building quality. Combined with fuzzy comprehensive evaluation method to analyze the advantages of BIM technology in building water supply and drainage design. Therefore, application prospects of BIM technology are very worthy of promotion.

Unilobar Versus Bilobar Biliary Drainage: Effect on Quality of Life and Bilirubin Level Reduction

PubMed Central

Gamanagatti, Shivanand; Singh, Tejbir; Sharma, Raju; Srivastava, Deep N; Dash, Nihar Ranjan; Garg, Pramod Kumar

2016-01-01

Background: Percutaneous biliary drainage is an accepted palliative treatment for malignant biliary obstruction. Purpose: To assess the effect on quality of life (QOL) and bilirubin level reduction in patients with inoperable malignant biliary obstruction treated by unilobar or bilobar percutaneous transhepatic biliary drainage (PTBD). Materials and Methods: Over a period of 2 years, 49 patients (age range, 22–75 years) of inoperable malignant biliary obstruction were treated by PTBD. Technical and clinical success rates, QOL, patency rates, survival rates, and complications were recorded. Clinical success rates, QOL, and bilirubin reduction were compared in patients treated with complete (n = 21) versus partial (n = 28) liver parenchyma drainage. QOL before and 1 month after biliary drainage were analyzed retrospectively between these two groups. Results: Biliary drainage was successful in all 49 patients, with an overall significant reduction of the postintervention bilirubin levels (P < 0.001) resulting in overall clinical success rate of 89.97%. Clinical success rates were similar in patients treated with whole-liver drainage versus partial-liver drainage. Mean serum bilirubin level before PTBD was 19.85 mg/dl and after the procedure at 1 month was 6.02 mg/dl. The mean baseline functional score was 39.35, symptom scale score was 59.55, and global health score was 27.45. At 1 month, mean functional score was 61.25, symptom scale score was 36.0 4, and global health score was 56.33, with overall significant improvement in QOL (<0.001). There was a statistically significant difference in the improvement of the QOL scores (P = 0.002), among patients who achieved clinical success, compared with those patients who did not achieve clinical success at 1 month. We did not find any significant difference in the QOL scores in patients according to the amount of liver drained (unilateral or bilateral drainage), the type of internalization used (ring biliary or stent). Overall, minor and major complications rates were 14.3% and 8.1%, respectively. Conclusion: Percutaneous biliary drainage provides good palliation of malignant obstructive jaundice. Partial-liver drainage achieved results as good as those after complete liver drainage with significant improvements in QOL and reduction of the bilirubin level. PMID:26962281

Determining the soil hydraulic conductivity by means of a field scale internal drainage

NASA Astrophysics Data System (ADS)

Severino, Gerardo; Santini, Alessandro; Sommella, Angelo

2003-03-01

Spatial variations of water content in large extents soils (vadose zone) are highly affected by the natural heterogeneity of the porous medium. This implies that the magnitude of the hydraulic properties, especially the conductivity, varies in an irregular manner with scale. Determining mean values of hydraulic properties will not suffice to accurately quantify water flow in the vadose zone. At field scale proper field measurements have to be carried out, similar to standard laboratory methods that also characterize the spatial variability of the hydraulic properties. Toward this aim an internal drainage test has been conducted at Ponticelli site near Naples (Italy) where water content and pressure head were monitored at 50 locations of a 2×50 m 2 plot. The present paper illustrates a method to quantify the mean value and the spatial variability of the hydraulic parameters needed to calibrate the soil conductivity curve at field scale (hereafter defined as field scale hydraulic conductivity). A stochastic model that regards the hydraulic parameters as random space functions (RSFs) is derived by adopting the stream tube approach of Dagan and Bresler (1979). Owing to the randomness of the hydraulic parameters, even the water content θ will be a RSF whose mean value (hereafter termed field scale water content) is obtained as an ensemble average over all the realizations of a local analytical solution of Richards' equation. It is shown that the most frequent data collection should be carried out in the initial stage of the internal drainage experiment, when the most significant changes in water content occur. The model parameters are obtained by a standard least square optimization procedure using water content data at a certain depth (z=30 cm) for several times ( t=5, 24, 48, 96, 144, 216, 312, 408, 576, 744, 912 h). The reliability of the proposed method is then evaluated by comparing the predicted water content with observations at different depths ( z=45, 60, 75, and 90 cm). The calibration procedure is further verified by comparing the cumulative distribution of measured water content at different times with corresponding distribution obtained from the calibrated model.

Synthesis of natural flows at selected sites in and near the Milk River basin, Montana, 1928-89

USGS Publications Warehouse

Cary, L.E.; Parrett, Charles

1995-01-01

Natural monthly streamflows were synthesized for the years 1928-89 at 2 sites in the St. Mary River Basin and 11 sites in the Milk River Basin in north- central Montana. The sites are represented as nodes in a streamflow accounting model being developed by the Bureau of Reclamation for the Milk River Basin. Recorded flows at most sites have been affected by human activities, including reservoir storage and irrigation diversions. The flows at the model nodes were corrected for the effects of these activities to obtain synthesized flows. The synthesized flows at nodes with seasonal and short-term records were extended using a statistical technique. The methods of synthesis varied, depending on upstream activities and information available. Flows at sites in the St. Mary River Basin and at the Milk River at Eastern Crossing of International Boundary pre- viously had been synthesized. The flows at mainstem sites downstream from the Milk River at Eastern Crossing were synthesized by adding synthesized natural runoff from intervening drainage areas to natural flows for Milk River at Eastern Crossing. Natural runoff from intervening drainage areas was estimated by multiplying recorded flows at selected index gaging stations on tributary streams by the ratio of the intervening drainage area to the combined drainage area of the index stations. The recorded flows for Milk River at Western Crossing of International Boundary and for Peoples Creek near Dodson, Montana, were assumed to be natural flows. The synthesized annual flows at the mouth of the Milk River compared favorably with the recorded flows near the mouth when the effects of upstream irrigation were considered.

Percutaneous Transhepatic Biliary Drainage in the Management of Postsurgical Biliary Leaks in Patients with Nondilated Intrahepatic Bile Ducts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cozzi, Guido, E-mail: guido.cozzi@istitutotumori.mi.it; Severini, Aldo; Civelli, Enrico

2006-06-15

Purpose. To assess the feasibility of percutaneous transhepatic biliary drainage (PTBD) for the treatment of postsurgical biliary leaks in patients with nondilated intrahepatic bile ducts, its efficacy in restoring the integrity of bile ducts, and technical procedures to reduce morbidity. Methods. Seventeen patients out of 936 undergoing PTBD over a 20-year period had a noncholestatic liver and were retrospectively reviewed. All patients underwent surgery for cancer and suffered a postsurgical biliary leak of 345 ml/day on average; 71% were in poor condition and required permanent nutritional support. An endoscopic approach failed or was excluded due to inaccessibility of the bilemore » ducts. Results. Established biliary leaks and site of origin were diagnosed an average of 21 days (range 1-90 days) after surgery. In all cases percutaneous access to the biliary tree was achieved. An external (preleakage) drain was applied in 7 cases, 9 patients had an external-internal fistula bridging catheter, and 1 patient had a percutaneous hepatogastrostomy. Fistulas healed in an average of 31 days (range 3-118 days ) in 15 of 17 patients (88%) following PTBD. No major complications occurred after drainage. Post-PTBD cholangitis was observed in 6 of 17 patients (35%) and was related to biliary sludge formation occurring mostly when drainage lasted >30 days and was of the external-internal type. Median patient survival was 17.7 months and in all cases the repaired biliary leaks remained healed. Conclusions. PTBD is a feasible, effective, and safe procedure for the treatment of postsurgical biliary leaks. It is therefore a reliable alternative to surgical repair, which entails longer hospitalization and higher costs.« less

Malignant biliary disease: percutaneous interventions.

PubMed

Morgan, R A; Adam, A N

2001-09-01

Interventional radiologists have an important role in the management of patients with malignant biliary obstruction. This article describes the techniques for percutaneous biliary drainage, insertion of biliary endoprostheses, and the management of occluded biliary endoprostheses. Most procedures are performed by using fluoroscopic guidance alone. Ultrasound is also a useful modality for guiding biliary drainage, particularly drainage of the left biliary ducts. Patients should be treated by internal drainage if possible. Metallic endoprostheses can be inserted at the time of the initial biliary drainage procedure. Plastic tubes should be inserted a few days after biliary drainage because of their relatively large size compared with metallic stents. Occluded plastic stents should be replaced. Blocked metallic stents should be treated either by placement of additional overlapping metallic stents or by placement of plastic stents within the metallic stent lumen. Copyright 2001 by W.B. Saunders Company

Ureteric stents vs percutaneous nephrostomy for initial urinary drainage in children with obstructive anuria and acute renal failure due to ureteric calculi: a prospective, randomised study.

PubMed

ElSheemy, Mohammed S; Shouman, Ahmed M; Shoukry, Ahmed I; ElShenoufy, Ahmed; Aboulela, Waseem; Daw, Kareem; Hussein, Ahmed A; Morsi, Hany A; Badawy, Hesham

2015-03-01

To compare percutaneous nephrostomy (PCN) tube vs JJ ureteric stenting as the initial urinary drainage method in children with obstructive calcular anuria (OCA) and post-renal acute renal failure (ARF) due to bilateral ureteric calculi, to identify the selection criteria for the initial urinary drainage method that will improve urinary drainage, decrease complications and facilitate the subsequent definitive clearance of stones, as this comparison is lacking in the literature. A series of 90 children aged ≤12 years presenting with OCA and ARF due to bilateral ureteric calculi were included from March 2011 to September 2013 at Cairo University Pediatric Hospital in this randomised comparative study. Patients with grade 0-1 hydronephrosis, fever or pyonephrosis were excluded. No patient had any contraindication for either method of drainage. Stable patients (or patients stabilised by dialysis) were randomised (non-blinded, block randomisation, sealed envelope method) into PCN-tube or bilateral JJ-stent groups (45 patients for each group). Initial urinary drainage was performed under general anaesthesia and fluoroscopic guidance. We used 4.8-6 F JJ stents or 6-8 F PCN tubes. The primary outcomes were the safety and efficacy of both groups for the recovery of renal functions. Both groups were compared for operative and imaging times, complications, and the period required for a return to normal serum creatinine levels. The secondary outcomes included the number of subsequent interventions needed for clearance of stones. Additional analysis was done for factors affecting outcome within each group. All presented patients completed the study with intention-to-treat analysis. There was no significant difference between the PCN-tube and JJ-stent groups for the operative and imaging times, period for return to a normal creatinine level and failure of insertion. There were significantly more complications in the PCN-tube group. The stone size (>2 cm) was the only factor affecting the rates of mucosal complications, operative time and failure of insertion in the JJ-stent group. The degree of hydronephrosis significantly affected the operative time for PCN-tube insertion. Grade 2 hydronephrosis was associated with all cases of insertion failure in the PCN-tube group. The total number of subsequent interventions needed to clear stones was significantly higher in the PCN-tube group, especially in patients with bilateral stones destined for chemolytic dissolution (alkalinisation) or extracorporeal shockwave lithotripsy (ESWL). We recommend the use of JJ stents for initial urinary drainage for stones that will be subsequently treated with chemolytic dissolution or ESWL, as this will lower the total number of subsequent interventions needed to clear the stones. This is also true for stones destined for ureteroscopy (URS), as JJ-stent insertion will facilitate subsequent URS due to previous ureteric stenting. Mild hydronephrosis will prolong the operative time for PCN-tube insertion and may increase the incidence of insertion failure. We recommend the use of PCN tube if the stone size is >2 cm, as there was a greater risk of possible iatrogenic ureteric injury during stenting with these larger ureteric stones in addition to prolongation of operative time with an increased incidence of failure. © 2014 The Authors. BJU International © 2014 BJU International.

Abdominal drainage following cholecystectomy: high, low, or no suction?

PubMed Central

McCormack, T. T.; Abel, P. D.; Collins, C. D.

1983-01-01

A prospective trial to assess the effect of suction in an abdominal drain following cholecystectomy was carried out. Three types of closed drainage system were compared: a simple tube drain, a low negative pressure drain, and a high negative pressure drain: 120 consecutive patients undergoing cholecystectomy were randomly allocated to one of the three drainage groups. There was no significant difference in postoperative pyrexia, wound infection, chest infection, or hospital stay. This study failed to demonstrate any clinically useful difference between high negative pressure, low negative pressure, and static drainage system were compared: a simple tube drain, a low negative used, suction is not necessary and a simple tube drain (greater than 6 mm internal diameter) is the most effective form of drainage. PMID:6614773

AMELIORATION OF ACID MINE DRAINAGE USING REACTIVE MIXTURES IN PERMEABLE REACTIVE BARRIERS

EPA Science Inventory

The generation and release of acidic drainage from mine wastes is an environmental problem of international scale. The use of zero-valent iron and/or iron mixtures in subsurface Permeable Reactive Barriers (PRB) presents a possible passive alternative for remediating acidic grou...

Flood Impact Assessment in the Surrounding Area of Suvarnabhumi Airport, Thailand

NASA Astrophysics Data System (ADS)

Tingsanchali, Tawatchai; Eng, D.

2009-03-01

The existence of the Second Bangkok International Airport (SBIA) or the Suvarnabhumi International Airport induces more adverse effect to the flooding situation in its surrounding area. Due to limited drainage capacity, during a heavy storm, flooding in the surrounding area occurs over the area. The objective of the study is to find the most suitable flood control and drainage system that can drain floodwater from the surrounding area of 624 sq. km with minimum flood damages and impact to social and living conditions of the people in the study area. This study involves the application of MIKE FLOOD hydrodynamic model for determining the relative effects of flood control and drainage system in the surrounding area of the airport. The results of the study show that flood damages mostly occur in the central and downstream parts of the study area where drainage is insufficient. Flood depth and duration are main parameters used for the estimation of flood losses. Flood mitigation and management in the surrounding area of SBIA is planned by pumping water of 100 m3/s from Klong Samrong canal inside the study area through the proposed drainage channel to the Gulf of Thailand. The existing dikes along boundaries of the study area can protect water from the outer area to enter into the surrounding area of the airport. Flood simulation shows that a canal with capacity of 100 m3/s and a pumping station at the downstream end of the canal are required to cope with the drainage capacity for the flood of 100 years return period. A flood drainage channel of capacity of 100 m3/s is designed and will be constructed to drain flood from Klong Samrong to the sea. On the other hand, the embankment along the proposed drainage canal project improves traffic flow in the vicinity of the airport. On economic benefit, the project investment cost is Baht 8,410 million. The project benefit cost ratio is 2.12 with the economic internal rate of return of 15.61%. The construction period is 4 years. Environmental and social impacts are investigated and counter measures are proposed to reduce the impacts. The study considers compensating scheme for people who are directly affected by the flood drainage project and those who will lose their lands or their professions. Considerations are also extended to people who are indirectly affected by the project. Institutional framework is recommended to be established to manage flood control and drainage and water resources in the surrounding area of the airport.

What role for law in achieving transboundary drainage basin security?--the development and testing of the Legal Assessment Model (LAM) for transboundary watercourse states.

PubMed

Wouters, P K

2004-01-01

The beneficial use of the world's transboundary waters raises difficult issues for drainage basin security on most parts of the globe. International law provides that each transboundary watercourse State is entitled to, and obliged to ensure, an "equitable and reasonable use" of these shared waters. The IWLRI developed and tested a Legal Assessment Model (LAM) through the work of interdisciplinary teams working in three different transboundary situations--China (upstream), Mozambique (downstream) and Palestine (shared groundwater). The LAM provides a tool for transboundary watercourse States to use in the preparation of their national water strategy for use at the national and international levels. The model should now be tested at the basin level, with a view to assisting to accomplish the peaceful and rational use of transboundary waters in line with the governing rule of international law and thereby to facilitate the overall policy objective of drainage basin security.

Evaluation of drainage-area ratio method used to estimate streamflow for the Red River of the North Basin, North Dakota and Minnesota

USGS Publications Warehouse

Emerson, Douglas G.; Vecchia, Aldo V.; Dahl, Ann L.

2005-01-01

The drainage-area ratio method commonly is used to estimate streamflow for sites where no streamflow data were collected. To evaluate the validity of the drainage-area ratio method and to determine if an improved method could be developed to estimate streamflow, a multiple-regression technique was used to determine if drainage area, main channel slope, and precipitation were significant variables for estimating streamflow in the Red River of the North Basin. A separate regression analysis was performed for streamflow for each of three seasons-- winter, spring, and summer. Drainage area and summer precipitation were the most significant variables. However, the regression equations generally overestimated streamflows for North Dakota stations and underestimated streamflows for Minnesota stations. To correct the bias in the residuals for the two groups of stations, indicator variables were included to allow both the intercept and the coefficient for the logarithm of drainage area to depend on the group. Drainage area was the only significant variable in the revised regression equations. The exponents for the drainage-area ratio were 0.85 for the winter season, 0.91 for the spring season, and 1.02 for the summer season.

Endoscopic ultrasound-guided biliary drainage

PubMed Central

Chavalitdhamrong, Disaya; Draganov, Peter V

2012-01-01

Endoscopic ultrasound (EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography (ERCP). EUS-guided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques. EUS-guided biliary drainage is an attractive option because of its minimally invasive, single step procedure which provides internal biliary decompression. Multiple investigators have reported high success and low complication rates. Unfortunately, high quality prospective data are still lacking. We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure. PMID:22363114

Guidelines for the design of subsurface drainage systems for highway structural sections

DOT National Transportation Integrated Search

1972-06-01

Design criteria and a design method for pavement subsurface drainage systems include inflow-outflow method of analysis, open graded drainage layers, collector drains, pipe outlets and markers. Design examples are given for embankment sections, cut se...

Description and spatial inference of soil drainage using matrix soil colours in the Lower Hunter Valley, New South Wales, Australia

PubMed Central

McBratney, Alex B.; Minasny, Budiman

2018-01-01

Soil colour is often used as a general purpose indicator of internal soil drainage. In this study we developed a necessarily simple model of soil drainage which combines the tacit knowledge of the soil surveyor with observed matrix soil colour descriptions. From built up knowledge of the soils in our Lower Hunter Valley, New South Wales study area, the sequence of well-draining → imperfectly draining → poorly draining soils generally follows the colour sequence of red → brown → yellow → grey → black soil matrix colours. For each soil profile, soil drainage is estimated somewhere on a continuous index of between 5 (very well drained) and 1 (very poorly drained) based on the proximity or similarity to reference soil colours of the soil drainage colour sequence. The estimation of drainage index at each profile incorporates the whole-profile descriptions of soil colour where necessary, and is weighted such that observation of soil colour at depth and/or dominantly observed horizons are given more preference than observations near the soil surface. The soil drainage index, by definition disregards surficial soil horizons and consolidated and semi-consolidated parent materials. With the view to understanding the spatial distribution of soil drainage we digitally mapped the index across our study area. Spatial inference of the drainage index was made using Cubist regression tree model combined with residual kriging. Environmental covariates for deterministic inference were principally terrain variables derived from a digital elevation model. Pearson’s correlation coefficients indicated the variables most strongly correlated with soil drainage were topographic wetness index (−0.34), mid-slope position (−0.29), multi-resolution valley bottom flatness index (−0.29) and vertical distance to channel network (VDCN) (0.26). From the regression tree modelling, two linear models of soil drainage were derived. The partitioning of models was based upon threshold criteria of VDCN. Validation of the regression kriging model using a withheld dataset resulted in a root mean square error of 0.90 soil drainage index units. Concordance between observations and predictions was 0.49. Given the scale of mapping, and inherent subjectivity of soil colour description, these results are acceptable. Furthermore, the spatial distribution of soil drainage predicted in our study area is attuned with our mental model developed over successive field surveys. Our approach, while exclusively calibrated for the conditions observed in our study area, can be generalised once the unique soil colour and soil drainage relationship is expertly defined for an area or region in question. With such rules established, the quantitative components of the method would remain unchanged. PMID:29682425

Description and spatial inference of soil drainage using matrix soil colours in the Lower Hunter Valley, New South Wales, Australia.

PubMed

Malone, Brendan P; McBratney, Alex B; Minasny, Budiman

2018-01-01

Soil colour is often used as a general purpose indicator of internal soil drainage. In this study we developed a necessarily simple model of soil drainage which combines the tacit knowledge of the soil surveyor with observed matrix soil colour descriptions. From built up knowledge of the soils in our Lower Hunter Valley, New South Wales study area, the sequence of well-draining → imperfectly draining → poorly draining soils generally follows the colour sequence of red → brown → yellow → grey → black soil matrix colours. For each soil profile, soil drainage is estimated somewhere on a continuous index of between 5 (very well drained) and 1 (very poorly drained) based on the proximity or similarity to reference soil colours of the soil drainage colour sequence. The estimation of drainage index at each profile incorporates the whole-profile descriptions of soil colour where necessary, and is weighted such that observation of soil colour at depth and/or dominantly observed horizons are given more preference than observations near the soil surface. The soil drainage index, by definition disregards surficial soil horizons and consolidated and semi-consolidated parent materials. With the view to understanding the spatial distribution of soil drainage we digitally mapped the index across our study area. Spatial inference of the drainage index was made using Cubist regression tree model combined with residual kriging. Environmental covariates for deterministic inference were principally terrain variables derived from a digital elevation model. Pearson's correlation coefficients indicated the variables most strongly correlated with soil drainage were topographic wetness index (-0.34), mid-slope position (-0.29), multi-resolution valley bottom flatness index (-0.29) and vertical distance to channel network (VDCN) (0.26). From the regression tree modelling, two linear models of soil drainage were derived. The partitioning of models was based upon threshold criteria of VDCN. Validation of the regression kriging model using a withheld dataset resulted in a root mean square error of 0.90 soil drainage index units. Concordance between observations and predictions was 0.49. Given the scale of mapping, and inherent subjectivity of soil colour description, these results are acceptable. Furthermore, the spatial distribution of soil drainage predicted in our study area is attuned with our mental model developed over successive field surveys. Our approach, while exclusively calibrated for the conditions observed in our study area, can be generalised once the unique soil colour and soil drainage relationship is expertly defined for an area or region in question. With such rules established, the quantitative components of the method would remain unchanged.

Lymphoscintigraphy Can Select Breast Cancer Patients for Internal Mammary Chain Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hindie, Elif, E-mail: elif.hindie@sls.aphp.fr; Department of Nuclear Medicine, CHU de Bordeaux, University of Bordeaux-Segalen, Bordeaux; Groheux, David

2012-07-15

Purpose: Given the risk of undesired toxicity, prophylactic internal mammary (IM) chain irradiation should be offered only to patients at high risk of occult involvement. Lymphoscintigraphy for axillary sentinel node biopsy might help in selecting these patients. Methods and Materials: We reviewed published studies with the following selection criteria: {>=}300 breast cancer patients referred for axilla sentinel node biopsy; scintigraphy performed after peritumoral or intratumoral tracer injection; IM biopsy in the case of IM drainage; and axilla staged routinely independent of IM status. Results: Six prospective studies, for a total of 3,876 patients, fulfilled the inclusion criteria. Parasternal drainage wasmore » present in 792 patients (20.4%). IM biopsy was performed in 644 patients and was positive in 111 (17.2%). Of the positive IM biopsies, 40% were associated with tumors in the lateral breast quadrants. A major difference in the IM positivity rate was found according to the axilla sentinel node status. In patients with negative axilla, the IM biopsy was positive in 7.8% of cases. In patients with positive axilla, however, the IM biopsy was positive in 41% (p < .00001). Because biopsy of multiple IM hot nodes is difficult, the true risk could be even greater, probably close to 50%. Conclusions: Patients with IM drainage on lymphoscintigraphy and a positive axilla sentinel node have a high risk of occult IM involvement. These women should be considered for IM radiotherapy.« less

Glacier generated floods

USGS Publications Warehouse

Walder, J.S.; Fountain, A.G.; ,

1997-01-01

Destructive floods result from drainage of glacier-dammed lakes and sudden release of water stored within glaciers. There is a good basis - both empirical and theoretical - for predicting the magnitude of floods from ice-dammed lakes, although some aspects of flood initiation need to be better understood. In contrast, an understanding of floods resulting from release of internally stored water remains elusive, owing to lack of knowledge of how and where water is stored and to inadequate understanding of the complex physics of the temporally and spatially variable subglacial drainage system.Destructive floods result from drainage of glacier-dammed lakes and sudden release of water stored within glaciers. There is a good basis - both empirical and theoretical - for predicting the magnitude of floods from ice-dammed lakes, although some aspects of flood initiation need to be better understood. In contrast, an understanding of floods resulting from release of internally stored water remains elusive, owing to lack of knowledge of how and where water is stored and to inadequate understanding of the complex physics of the temporally and spatially variable subglacial drainage system.

Urban hydrology

NASA Astrophysics Data System (ADS)

The Third International Conference on Urban Storm Drainage will be held in Goteborg, Sweden, June 4-8, 1984. Contact A. Sjoborg, Chalmers Univ. of Technology, Goteborg, Sweden, for more information. The Fourth Conference will be in late August 1987 in Lausanne, Switzerland, and the Fifth Conference is planned for Tokyo in 1990. The proceedings of the First International Conference, held in Southampton, England, in April 1978, are available from Wiley-Interscience under the title “Urban Storm Drainage.”The proceedings of the Second International Conference, held in Urbana, Illinois, in June 1981, are available from Water Resources Publications, Littleton, Colo., under the title, “Urban Stormwater Hydraulics and Hydrology” and “Urban Stormwater Quality, Management, and Planning.”

Climate change impacts on rainfall extremes and urban drainage: state-of-the-art review

NASA Astrophysics Data System (ADS)

Willems, Patrick; Olsson, Jonas; Arnbjerg-Nielsen, Karsten; Beecham, Simon; Pathirana, Assela; Bülow Gregersen, Ida; Madsen, Henrik; Nguyen, Van-Thanh-Van

2013-04-01

Under the umbrella of the IWA/IAHR Joint Committee on Urban Drainage, the International Working Group on Urban Rainfall (IGUR) has reviewed existing methodologies for the analysis of long-term historical and future trends in urban rainfall extremes and their effects on urban drainage systems, due to anthropogenic climate change. Current practises have several limitations and pitfalls, which are important to be considered by trend or climate change impact modellers and users of trend/impact results. The review considers the following aspects: Analysis of long-term historical trends due to anthropogenic climate change: influence of data limitation, instrumental or environmental changes, interannual variations and longer term climate oscillations on trend testing results. Analysis of long-term future trends due to anthropogenic climate change: by complementing empirical historical data with the results from physically-based climate models, dynamic downscaling to the urban scale by means of Limited Area Models (LAMs) including explicitly small-scale cloud processes; validation of RCM/GCM results for local conditions accounting for natural variability, limited length of the available time series, difference in spatial scales, and influence of climate oscillations; statistical downscaling methods combined with bias correction; uncertainties associated with the climate forcing scenarios, the climate models, the initial states and the statistical downscaling step; uncertainties in the impact models (e.g. runoff peak flows, flood or surcharge frequencies, and CSO frequencies and volumes), including the impacts of more extreme conditions than considered during impact model calibration and validation. Implications for urban drainage infrastructure design and management: upgrading of the urban drainage system as part of a program of routine and scheduled replacement and renewal of aging infrastructure; how to account for the uncertainties; flexible and sustainable solutions; adaptive approach that provides inherent flexibility and reversibility and avoids closing off options; importance of active learning. References: Willems, P., Olsson, J., Arnbjerg-Nielsen, K., Beecham, S., Pathirana, A., Bülow Gregersen, I., Madsen, H., Nguyen, V-T-V. (2012). Impacts of climate change on rainfall extremes and urban drainage. IWA Publishing, 252 p., Paperback Print ISBN 9781780401256; Ebook ISBN 9781780401263 Willems, P., Arnbjerg-Nielsen, K., Olsson, J., Nguyen, V.T.V. (2012), 'Climate change impact assessment on urban rainfall extremes and urban drainage: methods and shortcomings', Atmospheric Research, 103, 106-118

Improved vacuum sealing drainage for treatment of surgical site infection following posterior spinal internal fixation

PubMed Central

Zhang, Hengyan; Li, Qiyi

2018-01-01

Abstract Rationale: Surgical site infection (SSI) following spine surgeries involving internal fixation often require removing the instrument; however, this can cause spinal instability. Previous reports have demonstrated the usefulness of vacuum sealing drainage (VSD) therapy, but the cases require wound opening, aseptic condition to replace the VSD device, and a secondary operation to close the wound. Thus, to improve the VSD treatment and develop a maneuverable procedure, make sense in spine surgery. Patients concerns: A 59-year-old male patient with a T12 vertebral fracture was affected by SSIs after spinal osteotomy with internal fixation. Diagnoses: The patient complained of wound exudation and had a fever 3 weeks after posterior spinal surgery. Initial serum investigations showed elevated white blood cell count and bacterial cultures of wound exudate were positive for Enterococcus faecalis. Therefore, SSI is confirmed. Interventions: The infection was not controlled after 2 debridements, so the patient was treated with VSD treatment. The VSD foam dressings containing a drainage tube were placed into the wound from the exudation site of the wound until they contacted the internal fixation devices. After covering external fixation devices, continuous drainage was performed for 24 h. The VSD device was replaced every 4 to 5 days until the wound effusion stopped. All of the operations were performed at the bedside without complex manipulation or secondary closure under harsh aseptic condition. Outcomes: Wound exudation decreased remarkably and the infection was controlled 2 weeks after the application of VSD treatment. After 5 weeks, inflammatory indicators all decreased to normal levels and the exudate of the wound had stopped. The VSD treatment was then terminated and the drainage site of the wound was sutured. After 7 weeks, complete wound healing was achieved and no infection recurred during the 6-month follow-up. Lessons: VSD could be a reliable treatment for SSIs that require preservation of internal fixation. Complete opening of the wound during the VSD treatment and secondary wound closure surgery were avoided. PMID:29443786

Are there still roles for exocrine bladder drainage and portal venous drainage for pancreatic allografts?

PubMed

Young, Carlton J

2009-02-01

Controversy remains regarding the best methodology of handling exocrine pancreatic fluid and pancreatic venous effluent. Bladder drainage has given way to enteric drainage. However, is there an instance in which bladder drainage is preferable? Also, hyperinsulinemia, as a result of systemic venous drainage (SVD), is claimed to be proatherosclerotic, whereas portal venous drainage (PVD) is more physiologic and less atherosclerotic. Bladder drainage remains a viable method of exocrine pancreas drainage, but evidence is sparse that measuring urinary amylase has a substantial benefit in the early detection of acute rejection in all types of pancreas transplants. Currently, there is no incontrovertible evidence that systemic hyperinsulinemia is proatherosclerotic, whereas recent metabolic studies on SVD and PVD showed that there was no benefit to PVD. Given the advent of newer immunosuppressive agents and overall lower acute rejection rates, the perceived benefit of bladder drainage as a means to measure urinary amylase as an early marker of rejection has not been substantiated. However, there may be a selective role for bladder drainage in 'high risk' pancreases. Also, without a clear-cut metabolic benefit to PVD over SVD, it remains the surgeon's choice as to which method to use.

Development of ocular viscosity characterization method.

PubMed

Shu-Hao Lu; Guo-Zhen Chen; Leung, Stanley Y Y; Lam, David C C

2016-08-01

Glaucoma is the second leading cause for blindness. Irreversible and progressive optic nerve damage results when the intraocular pressure (IOP) exceeds 21 mmHg. The elevated IOP is attributed to blocked fluid drainage from the eye. Methods to measure the IOP are widely available, but methods to measure the viscous response to blocked drainage has yet been developed. An indentation method to characterize the ocular flow is developed in this study. Analysis of the load-relaxation data from indentation tests on drainage-controlled porcine eyes showed that the blocked drainage is correlated with increases in ocular viscosity. Successful correlation of the ocular viscosity with drainage suggests that ocular viscosity maybe further developed as a new diagnostic parameter for assessment of normal tension glaucoma where nerve damage occurs without noticeable IOP elevation; and as a diagnostic parameter complimentary to conventional IOP in conventional diagnosis.

Preoperative biliary drainage in hilar cholangiocarcinoma: When and how?

PubMed Central

Paik, Woo Hyun; Loganathan, Nerenthran; Hwang, Jin-Hyeok

2014-01-01

Hilar cholangiocarcinoma is a tumor of the extrahepatic bile duct involving the left main hepatic duct, the right main hepatic duct, or their confluence. Biliary drainage in hilar cholangiocarcinoma is sometimes clinically challenging because of complexities associated with the level of biliary obstruction. This may result in some adverse events, especially acute cholangitis. Hence the decision on the indication and methods of biliary drainage in patients with hilar cholangiocarcinoma should be carefully evaluated. This review focuses on the optimal method and duration of preoperative biliary drainage (PBD) in resectable hilar cholangiocarcinoma. Under certain special indications such as right lobectomy for Bismuth type IIIA or IV hilar cholangiocarcinoma, or preoperative portal vein embolization with chemoradiation therapy, PBD should be strongly recommended. Generally, selective biliary drainage is enough before surgery, however, in the cases of development of cholangitis after unilateral drainage or slow resolving hyperbilirubinemia, total biliary drainage may be considered. Although the optimal preoperative bilirubin level is still a matter of debate, the shortest possible duration of PBD is recommended. Endoscopic nasobiliary drainage seems to be the most appropriate method of PBD in terms of minimizing the risks of tract seeding and inflammatory reactions. PMID:24634710

Comparison of Peak-Flow Estimation Methods for Small Drainage Basins in Maine

USGS Publications Warehouse

Hodgkins, Glenn A.; Hebson, Charles; Lombard, Pamela J.; Mann, Alexander

2007-01-01

Understanding the accuracy of commonly used methods for estimating peak streamflows is important because the designs of bridges, culverts, and other river structures are based on these flows. Different methods for estimating peak streamflows were analyzed for small drainage basins in Maine. For the smallest basins, with drainage areas of 0.2 to 1.0 square mile, nine peak streamflows from actual rainfall events at four crest-stage gaging stations were modeled by the Rational Method and the Natural Resource Conservation Service TR-20 method and compared to observed peak flows. The Rational Method had a root mean square error (RMSE) of -69.7 to 230 percent (which means that approximately two thirds of the modeled flows were within -69.7 to 230 percent of the observed flows). The TR-20 method had an RMSE of -98.0 to 5,010 percent. Both the Rational Method and TR-20 underestimated the observed flows in most cases. For small basins, with drainage areas of 1.0 to 10 square miles, modeled peak flows were compared to observed statistical peak flows with return periods of 2, 50, and 100 years for 17 streams in Maine and adjoining parts of New Hampshire. Peak flows were modeled by the Rational Method, the Natural Resources Conservation Service TR-20 method, U.S. Geological Survey regression equations, and the Probabilistic Rational Method. The regression equations were the most accurate method of computing peak flows in Maine for streams with drainage areas of 1.0 to 10 square miles with an RMSE of -34.3 to 52.2 percent for 50-year peak flows. The Probabilistic Rational Method was the next most accurate method (-38.5 to 62.6 percent). The Rational Method (-56.1 to 128 percent) and particularly the TR-20 method (-76.4 to 323 percent) had much larger errors. Both the TR-20 and regression methods had similar numbers of underpredictions and overpredictions. The Rational Method overpredicted most peak flows and the Probabilistic Rational Method tended to overpredict peak flows from the smaller (less than 5 square miles) drainage basins and underpredict peak flows from larger drainage basins. The results of this study are consistent with the most comprehensive analysis of observed and modeled peak streamflows in the United States, which analyzed statistical peak flows from 70 drainage basins in the Midwest and the Northwest.

Comparing morphologies of drainage basins on Mars and Earth using integral-geometry and neural maps

NASA Technical Reports Server (NTRS)

Stepinski, T. F.; Coradetti, S.

2004-01-01

We compare morphologies of drainage basins on Mars and Earth in order to confine the formation process of Martian valley networks. Basins on both planets are computationally extracted from digital topography. Integral-geometry methods are used to represent each basin by a circularity function that encapsulates its internal structure. The shape of such a function is an indicator of the style of fluvial erosion. We use the self-organizing map technique to construct a similarity graph for all basins. The graph reveals systematic differences between morphologies of basins on the two planets. This dichotomy indicates that terrestrial and Martian surfaces were eroded differently. We argue that morphologies of Martian basins are incompatible with runoff from sustained, homogeneous rainfall. Fluvial environments compatible with observed morphologies are discussed. We also construct a similarity graph based on the comparison of basins hypsometric curves to demonstrate that hypsometry is incapable of discriminating between terrestrial and Martian basins. INDEX TERMS: 1824 Hydrology: Geomorphology (1625); 1886 Hydrology: Weathering (1625); 5415 Planetology: Solid Surface Planets: Erosion and weathering; 6225 Planetology: Solar System Objects Mars. Citation: Stepinski, T. F., and S. Coradetti (2004), Comparing morphologies of drainage basins on Mars and Earth using integral-ge

Contrast radiographic study of venous drainage of the corpus cavernosum and the corpus spongiosum of the cat penis.

PubMed

Amiri, Ali Akbar; Gilanpour, Hassan; Veshkini, Abbas

2014-01-01

The aim of this study was to determine the drainage routes of the corpus cvernosum penis and the corpus spongiosum penis in the cat using contrast cavernosography. Five male cats, 1.5-2.5 years old, weighing between 4.5 and 5.5 kg were investigated. The cats were anesthetized and the root and the proximal part of the penis were exposed by an incision on the perineum reaching the scrotum. Each cat was radiographed in lateral and dorsal recumbency before and during injection of contrast medium into the erectile bodies. The corpus spongiosum penis was injected at the bulb of the penis and the corpus cavernosum penis at the root. Injection of contrast media into the cavernous bodies showed that both the external and internal iliac veins drain the erectile bodies into the caudal vena cava. Drainage from the corpus spongiosum penis was from the bulb for the proximal part and from the glans for the distal part. The corpus cavernosum penis was drained only proximally, from the crura. There was a network of veins above the pelvic symphysis and the drainage of erectile bodies where through various routes into the internal and external iliac veins.

Extraction of Martian valley networks from digital topography

NASA Technical Reports Server (NTRS)

Stepinski, T. F.; Collier, M. L.

2004-01-01

We have developed a novel method for delineating valley networks on Mars. The valleys are inferred from digital topography by an autonomous computer algorithm as drainage networks, instead of being manually mapped from images. Individual drainage basins are precisely defined and reconstructed to restore flow continuity disrupted by craters. Drainage networks are extracted from their underlying basins using the contributing area threshold method. We demonstrate that such drainage networks coincide with mapped valley networks verifying that valley networks are indeed drainage systems. Our procedure is capable of delineating and analyzing valley networks with unparalleled speed and consistency. We have applied this method to 28 Noachian locations on Mars exhibiting prominent valley networks. All extracted networks have a planar morphology similar to that of terrestrial river networks. They are characterized by a drainage density of approx.0.1/km, low in comparison to the drainage density of terrestrial river networks. Slopes of "streams" in Martian valley networks decrease downstream at a slower rate than slopes of streams in terrestrial river networks. This analysis, based on a sizable data set of valley networks, reveals that although valley networks have some features pointing to their origin by precipitation-fed runoff erosion, their quantitative characteristics suggest that precipitation intensity and/or longevity of past pluvial climate were inadequate to develop mature drainage basins on Mars.

Soil magnetic susceptibility: A quantitative proxy of soil drainage for use in ecological restoration

USGS Publications Warehouse

Grimley, D.A.; Wang, J.-S.; Liebert, D.A.; Dawson, J.O.

2008-01-01

Flooded, saturated, or poorly drained soils are commonly anaerobic, leading to microbially induced magnetite/maghemite dissolution and decreased soil magnetic susceptibility (MS). Thus, MS is considerably higher in well-drained soils (MS typically 40-80 ?? 10-5 standard international [SI]) compared to poorly drained soils (MS typically 10-25 ?? 10-5 SI) in Illinois, other soil-forming factors being equal. Following calibration to standard soil probings, MS values can be used to rapidly and precisely delineate hydric from nonhydric soils in areas with relatively uniform parent material. Furthermore, soil MS has a moderate to strong association with individual tree species' distribution across soil moisture regimes, correlating inversely with independently reported rankings of a tree species' flood tolerance. Soil MS mapping can thus provide a simple, rapid, and quantitative means for precisely guiding reforestation with respect to plant species' adaptations to soil drainage classes. For instance, in native woodlands of east-central Illinois, Quercus alba , Prunus serotina, and Liriodendron tulipifera predominantly occur in moderately well-drained soils (MS 40-60 ?? 10-5 SI), whereas Acer saccharinum, Carya laciniosa, and Fraxinus pennsylvanica predominantly occur in poorly drained soils (MS <20 ?? 10-5 SI). Using a similar method, an MS contour map was used to guide restoration of mesic, wet mesic, and wet prairie species to pre-settlement distributions at Meadowbrook Park (Urbana, IL, U.S.A.). Through use of soil MS maps calibrated to soil drainage class and native vegetation occurrence, restoration efforts can be conducted more successfully and species distributions more accurately reconstructed at the microecosystem level. ?? 2008 Society for Ecological Restoration International.

Spontaneously removed biliary stent drainage versus T-tube drainage after laparoscopic common bile duct exploration.

PubMed

Xu, Yakun; Dong, Chengyong; Ma, Kexin; Long, Fei; Jiang, Keqiu; Shao, Ping; Liang, Rui; Wang, Liming

2016-09-01

Several studies have shown the safety and feasibility of laparoscopic common bile duct exploration (LCBDE) as a minimally invasive treatment options for choledocholithiasis. Use of T-tube or biliary stent drainage tube placement after laparoscopic choledochotomy for common bile duct (CBD) stones is still under debate. This study tried to confirm the safety of spontaneously removable biliary stent in the distal CBD after LCBDE to allow choledochus primary closure. A total of 47 patients with choledocholithiasis underwent LCBDE with primary closure and internal drainage using a spontaneously removable biliary stent drainage tube (stent group, N = 22) or T-tube (T-tube group, N = 25). Operative parameters and outcomes are compared. Surgical time, intraoperative blood loss, length of hospital stay, drainage tube removal time, postoperative intestinal function recovery, and cost of treatment were all significantly lower in the stent group as compared to that in the T-tube group (P < 0.05 for all). Otherwise, Bile leakage between the two groups had no significant difference (P > 0.05). The biliary stent drainage tube was excreted spontaneously 4 to 14 days after surgery with the exception of one case, where endoscopic removal of biliary tube was required due to failure of its spontaneous discharge. LCBDE with primary closure and use of spontaneously removable biliary stent drainage showed advantage over the use of traditional T-tube drainage in patients with choledocholithiasis.

Sentinel lymph node mapping in breast cancer: a critical reappraisal of the internal mammary chain issue.

PubMed

Manca, G; Volterrani, D; Mazzarri, S; Duce, V; Svirydenka, A; Giuliano, A; Mariani, G

2014-06-01

Although, like the axilla, the internal mammary nodes (IMNs) are a first-echelon nodal drainage site in breast cancer, the importance of their treatment has long been debated. Seminal randomized trials have failed to demonstrate a survival benefit from surgical IMN dissection, and several retrospective studies have shown that IMNs are rarely the first site of recurrence. However, the recent widespread adoption of sentinel lymph node (SLN) biopsy has stimulated a critical reappraisal of such early results. Furthermore, the higher proportion of screening-detected cancers, improved imaging and techniques (i.e., lymphoscintigraphy for radioguided SLN biopsy) make it possible to visualize lymphatic drainage to the IMNs. The virtually systematic application of adjuvant systemic and/or loco-regional radiotherapy encourages re-examination of the significance of IMN metastases. Moreover, randomized trials testing the value of postmastectomy irradiation and a meta-analysis of 78 randomized trials have provided high levels of evidence that local-regional tumor control is associated with long-term survival improvements. This benefit was limited to trials that used systemic chemotherapy, which was not routinely administered in the earlier studies. However, the contribution from IMN treatment is unclear. Lymphoscintigraphic studies have shown that a significant proportion of breast cancers have primary drainage to the IMNs, including approximately 30% of medial tumors and 15% of lateral tumors. In the few studies where IMN biopsy was performed, 20% of sentinel IMNs were metastatic. The risk of IMN involvement is higher in patients with medial tumors and positive axillary nodes. IMN metastasis has prognostic significance, as recognized by its inclusion in the American Joint Committee on Cancer staging criteria, and seems to have similar prognostic importance as axillary nodal involvement. Although routine IMN evaluation might be indicated, it has not been routinely performed, perhaps because IMN drainage with lymphoscintigraphy is more difficult to demonstrate than axillary drainage. This difference is due to technical reasons and not the absence of lymphatics to the IMN. Recent anatomical studies have confirmed a model of breast lymphatic drainage that comprises superficial, deep and perforating systems. The superficial system drains to the axilla, usually to a lymph node posterior to the pectoralis minor muscle. The deep system drains to the axilla and also anastomoses with the perforating system which drains to the IMNs. The perforating system does not connect with the superficial system. The prevalence of IMN drainage tends to reflect the method of lymphoscintigraphy, where peritumoral (deep lymphatic system) injections have a much higher likelihood of IMN drainage than subareolar or subdermal (superficial lymphatic system) injections. The fused SPECT/CT images represent a further technical solution to increase the identification of IMNs and consequently can significantly reduce the false negative rate of sentinel lymph node biopsy. Before mature results from current and future randomized trials assessing the benefit of IMN irradiation become available, lymphoscintigraphy and IMNs biopsy may be used to guide decisions regarding systemic and local-regional treatment. However, even in patients with visualized primary IMN drainage, the potential benefit of treatment should be balanced against the risk of added morbidity.

Vaccum drainage system application in the management of operation-related non-regional epidural hematoma

PubMed Central

2013-01-01

Background Epidural intracranial hematoma is one of the most common complications of surgeries for intracranial tumors. The non-regional epidural hematoma is related to severe fluctuation of the intracranial pressure during the operation. The traditional management of hematoma evacuation through craniotomy is time-consuming and may aggravate intracranial pressure imbalance, which causes further complications. We designed a method using vaccum epidural drainage system, and tried to evaluate advantage and the disadvantage of this new technique. Methods Seven patients of intracranial tumors were selected. All of the patients received tumor resection and intra-operative non-regional epidural hematoma was confirmed through intra-operative ultrasound or CT scan. The vaccum drainage system was applied. Another ten patients who received craniotomy for intra-operative non-regional epidural hematoma evacuation were selected as comparison. Regular tests, like serial CT scan, were performed afterward to evaluate the effectiveness and to help deciding when to remove the drainage system. Results The vaccum drainage method was effective in epidual hemotoma clearance and prevented recurrent epidural hemorrhage. The drainage systems were removed within 4 days. All of the patients recovered well. No complications related to the drainage system were observed. Conclusions Compared to the traditional craniotomy, the new method of epidural hemoatoma management using vaccum epidural drainage system proved to be as effective in hematoma clearance, and was less-invasive and easier to perform, with less complication, shorter hospitalization, less economic burden, and better prognosis. PMID:23842198

Protocol of a prospective cohort study of the effect of different methods of drainage of neuropathic bladder on occurrence of symptomatic urinary infection, and adverse events related to the urinary drainage system in spinal cord injury patients

PubMed Central

Vaidyanathan, Subramanian; Soni, Bhakul M; Gurpreet, Singh; Mansour, Paul; Hughes, Peter L; Oo, Tun; Sett, Pradipkumar; Parsons, Keith F; Davies, John C

2001-01-01

Background To present a protocol of a prospective, cohort study in which four groups of spinal cord injury (SCI) patients will participate. (Patients with indwelling urethral catheter; patients who perform intermittent catheterisation without wearing a penile sheath; patients who perform intermittent catheterisation and wear penile sheath as well; and patients with penile sheath drainage). Objectives (1) What is the incidence of symptomatic urinary infection in men with spinal cord injury who use different types of bladder drainage? (2) Which are predisposing factors for the occurrence of symptomatic urinary infection in men with spinal cord injury who practise different methods of bladder drainage? (3) What is the incidence of catheter and urinary drainage system-related adverse events in the four groups of SCI patients? Patients The criteria for inclusion are as follow: (1) Male patients with neuropathic bladder due to spinal cord injury, who are registered with the Regional Spinal Injuries Centre, Southport, England. (2) Age: 18 years or above. (3) Patients who are willing to give informed consent for participation in the study. (4) Patients willing to be contacted every two weeks by a staff of the spinal unit for 36 months. (5) Patients who are willing to maintain an accurate record of adverse events related to urinary catheter and urinary drainage system and predisposing factors for the occurrence of symptomatic urinary infection. (6) Patients, who are stabilised in a particular method of bladder drainage, and therefore, unlikely to make a permanent change in the method of bladder drainage (e.g. from penile sheath drainage to the use of long-term indwelling catheter) during a foreseeable future. Methods The participants will be observed for a period of 36 months. A staff of the spinal injuries unit will contact the participants by telephone every two weeks on a mutually agreed day and time. The information obtained during this standardised telephonic interview conducted once in two weeks will be entered in a database. When a participant develops symptom(s) suggestive of urinary infection, he will undergo urine and blood tests, and imaging studies of the urinary tract. Conclusion This study will provide information regarding the occurrence of symptomatic urinary infection, predisposing factors for development of urinary infection, and adverse events related to urinary catheter and urinary drainage system in SCI patients using different methods of bladder drainage. PMID:11734072

Data harmonization and model performance

NASA Astrophysics Data System (ADS)

The Joint Committee on Urban Storm Drainage of the International Association for Hydraulic Research (IAHR) and International Association on Water Pollution Research and Control (IAWPRC) was formed in 1982. The current committee members are (no more than two from a country): B. C. Yen, Chairman (USA); P. Harremoes, Vice Chairman (Denmark); R. K. Price, Secretary (UK); P. J. Colyer (UK), M. Desbordes (France), W. C. Huber (USA), K. Krauth (FRG), A. Sjoberg (Sweden), and T. Sueishi (Japan).The IAHR/IAWPRC Joint Committee is forming a Task Group on Data Harmonization and Model Performance. One objective is to promote international urban drainage data harmonization for easy data and information exchange. Another objective is to publicize available models and data internationally. Comments and suggestions concerning the formation and charge of the Task Group are welcome and should be sent to: B. C. Yen, Dept. of Civil Engineering, Univ. of Illinois, 208 N. Romine St., Urbana, IL 61801.

EARLYDRAIN- outcome after early lumbar CSF-drainage in aneurysmal subarachnoid hemorrhage: study protocol for a randomized controlled trial

PubMed Central

2011-01-01

Background Aneurysmal subarachnoid hemorrhage (SAH) may be complicated by delayed cerebral ischemia, which is a major cause of unfavorable clinical outcome and death in SAH-patients. Delayed cerebral ischemia is presumably related to the development of vasospasm triggered by the presence of blood in the basal cisterns. To date, oral application of the calcium antagonist nimodipine is the only prophylactic treatment for vasospasm recognized under international guidelines. In retrospective trials lumbar drainage of cerebrospinal fluid has been shown to be a safe and feasible measure to remove the blood from the basal cisterns and decrease the incidence of delayed cerebral ischemia and vasospasm in the respective study populations. However, the efficacy of lumbar drainage has not been evaluated prospectively in a randomized controlled trial yet. Methods/Design This is a protocol for a 2-arm randomized controlled trial to compare an intervention group receiving early continuous lumbar CSF-drainage and standard neurointensive care to a control group receiving standard neurointensive care only. Adults suffering from a first aneurysmal subarachnoid hemorrhage whose aneurysm has been secured by means of coiling or clipping are eligible for trial participation. The effect of early CSF drainage (starting < 72 h after securing the aneurysm) will be measured in the following ways: the primary endpoint will be disability after 6 months, assessed by a blinded investigator during a personal visit or standardized telephone interview using the modified Rankin Scale. Secondary endpoints include mortality after 6 months, angiographic vasospasm, transcranial Doppler sonography (TCD) mean flow velocity in both middle cerebral arteries and rate of shunt insertion at 6 months after hospital discharge. Discussion Here, we present the study design of a multicenter prospective randomized controlled trial to investigate whether early application of a lumbar drainage improves clinical outcome after aneurysmal subarachnoid hemorrhage. Trial registration www.clinicaltrials.gov Identifier: NCT01258257 PMID:21917146

An application of the AHP in water resources management: a case study on urban drainage rehabilitation in Medan City

NASA Astrophysics Data System (ADS)

Tarigan, A. P. M.; Rahmad, D.; Sembiring, R. A.; Iskandar, R.

2018-02-01

This paper illustrates an application of Analytical Hierarchy Process (AHP) as a potential decision-making method in water resource management related to drainage rehabilitation. The prioritization problem of urban drainage rehabilitation in Medan City due to limited budget is used as a study case. A hierarchical structure is formed for the prioritization criteria and the alternative drainages to be rehabilitated. Based on the AHP, the prioritization criteria are ranked and a descending-order list of drainage is made in order to select the most favorable drainages to have rehabilitation. A sensitivity analysis is then conducted to check the consistency of the final decisions in case of minor changes in judgements. The results of AHP computed manually are compared with that using the software Expert Choice. It is observed that the top three ranked drainages are consistent, and both results of the AHP methods, calculated manually and performed using Expert Choice, are in agreement. It is hoped that the application of the AHP will help the decision-making process by the city government in the problem of urban drainage rehabilitation.

Preoperative endoscopic versus percutaneous transhepatic biliary drainage in potentially resectable perihilar cholangiocarcinoma (DRAINAGE trial): design and rationale of a randomized controlled trial.

PubMed

Wiggers, Jimme K; Coelen, Robert J S; Rauws, Erik A J; van Delden, Otto M; van Eijck, Casper H J; de Jonge, Jeroen; Porte, Robert J; Buis, Carlijn I; Dejong, Cornelis H C; Molenaar, I Quintus; Besselink, Marc G H; Busch, Olivier R C; Dijkgraaf, Marcel G W; van Gulik, Thomas M

2015-02-14

Liver surgery in perihilar cholangiocarcinoma (PHC) is associated with high postoperative morbidity because the tumor typically causes biliary obstruction. Preoperative biliary drainage is used to create a safer environment prior to liver surgery, but biliary drainage may be harmful when severe drainage-related complications deteriorate the patients' condition or increase the risk of postoperative morbidity. Biliary drainage can cause cholangitis/cholecystitis, pancreatitis, hemorrhage, portal vein thrombosis, bowel wall perforation, or dehydration. Two methods of preoperative biliary drainage are mostly applied: endoscopic biliary drainage, which is currently used in most regional centers before referring patients for surgical treatment, and percutaneous transhepatic biliary drainage. Both methods are associated with severe drainage-related complications, but two small retrospective series found a lower incidence in the number of preoperative complications after percutaneous drainage compared to endoscopic drainage (18-25% versus 38-60%, respectively). The present study randomizes patients with potentially resectable PHC and biliary obstruction between preoperative endoscopic or percutaneous transhepatic biliary drainage. The study is a multi-center trial with an "all-comers" design, randomizing patients between endoscopic or percutaneous transhepatic biliary drainage. All patients selected to potentially undergo a major liver resection for presumed PHC are eligible for inclusion in the study provided that the biliary system in the future liver remnant is obstructed (even if they underwent previous inadequate endoscopic drainage). Primary outcome measure is the total number of severe preoperative complications between randomization and exploratory laparotomy. The study is designed to detect superiority of percutaneous drainage: a provisional sample size of 106 patients is required to detect a relative decrease of 50% in the number of severe preoperative complications (alpha = 0.95; beta = 0.8). Interim analysis after inclusion of 53 patients (50%) will provide the definitive sample size. Secondary outcome measures encompass the success of biliary drainage, quality of life, and postoperative morbidity and mortality. The DRAINAGE trial is designed to identify a difference in the number of severe drainage-related complications after endoscopic and percutaneous transhepatic biliary drainage in patients selected to undergo a major liver resection for perihilar cholangiocarcinoma. Netherlands Trial Register [ NTR4243 , 11 October 2013].

Drainage network optimization for inundation mitigation case study of ITS Surabaya

NASA Astrophysics Data System (ADS)

Savitri, Yang Ratri; Lasminto, Umboro

2017-06-01

Institut Teknologi Sepuluh Nopember (ITS) Surabaya is one of engineering campus in Surabaya with an area of ± 187 ha, which consists of building and campus facilities. The campus is supported by drainage system planned according to the ITS Master Plan on 2002. The drainage system is planned with numbers of retention and detention pond based on the city concept of Zero Delta Q concept. However, in the rainy season, it frequently has inundation problems in several locations. The problems could be identified from two major sources, namely the internal campus facilities and external condition connected with the city drainage system. This paper described the capabilities of drainage network optimization to mitigate local urban drainage problem. The hydrology-hydraulic investigation was done by utilizing the Storm Water Management Model (SWMM) developed by US Environmental Protection Agency (EPA). The mitigation is based on several alternative that based on the existing condition and regarding the social problem. The study results showed that the management of the flow from external source could reduce final stored volume of the campus main channel by 31.75 %.

Innovative Technique for the Placement of the Drainage Tube for Microendoscopic Spinal Decompression.

PubMed

Mizuno, Kentaro; Mikami, Yasuo; Hase, Hitoshi; Ikeda, Takumi; Nagae, Masateru; Tonomura, Hitoshi; Shirai, Toshiharu; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2017-02-01

A technical note and retrospective study. The objectives were to describe a new method of drainage tube placement during microendoscopic spinal decompression, and compare the positioning and fluid discharge obtained with this method and the conventional method. To prevent postoperative epidural hematoma after microendoscopic decompression, a drainage tube must be placed in a suitable location. However, the narrow operative field makes precise control of the position of the tube technically difficult. We developed a method to reliably place the tube in the desired location. We use a Deschamps aneurysm needle with a slightly curved tip, which we call a drain passer. With the microendoscope in position, the drain passer, with a silk thread passed through the eye at the needle tip, is inserted percutaneously into the endoscopic field of view. The drainage tube is passed through the loop of silk thread protruding from the inside of the tubular retractor, and the thread is pulled to the outside, guiding the end of the drainage tube into the wound. This method was used in 23 cases at 44 intervertebral levels (drain passer group), and the conventional method in 20 cases at 32 intervertebral levels (conventional group). Postoperative plain radiographs were taken, and the amount of fluid discharge at postoperative hour 24 was measured. Drainage tube positioning was favorable at 43 intervertebral levels (97.7%) in the drain passer group and 26 intervertebral levels (81.3%) in the conventional group. Mean fluid discharge was 58.4±32.2 g in the drain passer group and 38.4±23.0 g in the conventional group. Positioning was significantly better and fluid discharge was significantly greater in the drain passer group. The results indicate that this method is a useful drainage tube placement technique for preventing postoperative epidural hematoma.

Plug identification in drainage system using electromagnetic wave

NASA Astrophysics Data System (ADS)

Hijriani, Arifa; Utama, Aji Surya; Boas, Andrianus; Mukti, M. Ridho; Widodo

2017-07-01

The evaluation of drainage system's performance is an important thing to do to prevent flooding. Conventionally the Government evaluates the drainage system by opening one by one the lid of drainage and detects the plug manually. This method is not effective and efficient because this method need many people, much time and relatively expensive. The purpose of this paper is to identify plugs in drainage system in G St. at Bandung Institute of Technology by using electromagnetic wave. Ground Penetrating Radar (GPR) is one of geophysics method that using electromagnetic wave with high frequency. GPR is a non-destructive method with high resolution imaging for shallow depth (˜100m) and relatively cheap. We could identify the plug without opening the lid manually so that we could save much time. GPR's sensitivity is depends on resistivity, magnetic permeability, and permittivity of an object. The result of this research is we could identify the plug on the radargram that observed by a build-up amplitude anomaly.

A safe and effective method for treatment of chronic subdural haematoma.

PubMed

Gurelik, Mustafa; Aslan, Adem; Gurelik, Bilge; Ozum, Unal; Karadag, Ozen; Kars, H Zafer

2007-02-01

Burr-hole irrigation and burr-hole drainage without irrigation are the most popular methods for treatment of chronic subdural haematoma. It is not well known if irrigation is necessary or which method has a higher recurrence rate. We compared the recurrence rates of those two methods. Forty-two patients were treated by burr-hole irrigation (irrigation group), whereas 38 patients were treated by burr-hole drainage (drainage group). Recurrence rate and its relation with sex, age, haematoma localization and aetiology were investigated in both groups. There was no significant difference between recurrence rates of the two groups. There was also no correlation between recurrence rate and age, sex, haematoma localization, or aetiology. There was no significant difference between recurrence rates of the two groups. Since the burr-hole drainage method is simpler to carry out, its use may be preferable.

Emergency percutaneous treatment in surgical bile duct injury.

PubMed

Carrafiello, Gianpaolo; Laganà, Domenico; Dizonno, Massimiliano; Ianniello, Andrea; Cotta, Elisa; Dionigi, Gianlorenzo; Dionigi, Renzo; Fugazzola, Carlo

2008-09-01

The aim of this study is to evaluate the efficacy of emergency percutaneous treatment in patients with surgical bile duct injury (SBDI). From May 2004 to May 2007, 11 patients (five men, six women; age range 26-80 years; mean age 58 years) with a critical clinical picture (severe jaundice, bile peritonitis, septic state) due to SBDI secondary to surgical or laparoscopic procedures were treated by percutaneous procedures. We performed four ultrasound-guided percutaneous drainages, four external-internal biliary drainages, one bilioplasty, and two plastic biliary stenting after 2 weeks of external-internal biliary drainage placement. All procedures had 100% technical success with no complications. The clinical emergencies resolved in 3-4 days in 100% of cases. All patients had a benign clinical course, and reoperation was avoided in 100% of cases. Interventional radiological procedures are effective in the emergency management of SBDI since they are minimally invasive and have a high success rate and a low incidence of complications compared to the more complex and dangerous surgical or laparoscopic options.

MR Elastography Can Be Used to Measure Brain Stiffness Changes as a Result of Altered Cranial Venous Drainage During Jugular Compression.

PubMed

Hatt, A; Cheng, S; Tan, K; Sinkus, R; Bilston, L E

2015-10-01

Compressing the internal jugular veins can reverse ventriculomegaly in the syndrome of inappropriately low pressure acute hydrocephalus, and it has been suggested that this works by "stiffening" the brain tissue. Jugular compression may also alter blood and CSF flow in other conditions. We aimed to understand the effect of jugular compression on brain tissue stiffness and CSF flow. The head and neck of 9 healthy volunteers were studied with and without jugular compression. Brain stiffness (shear modulus) was measured by using MR elastography. Phase-contrast MR imaging was used to measure CSF flow in the cerebral aqueduct and blood flow in the neck. The shear moduli of the brain tissue increased with the percentage of blood draining through the internal jugular veins during venous compression. Peak velocity of caudally directed CSF in the aqueduct increased significantly with jugular compression (P < .001). The mean jugular venous flow rate, amplitude, and vessel area were significantly reduced with jugular compression, while cranial arterial flow parameters were unaffected. Jugular compression influences cerebral CSF hydrodynamics in healthy subjects and can increase brain tissue stiffness, but the magnitude of the stiffening depends on the percentage of cranial blood draining through the internal jugular veins during compression—that is, subjects who maintain venous drainage through the internal jugular veins during jugular compression have stiffer brains than those who divert venous blood through alternative pathways. These methods may be useful for studying this phenomenon in patients with the syndrome of inappropriately low-pressure acute hydrocephalus and other conditions. © 2015 by American Journal of Neuroradiology.

Adaptation Options for Land Drainage Systems Towards Sustainable Agriculture and Environment: A Czech Perspective

NASA Astrophysics Data System (ADS)

Kulhavý, Zbyněk; Fučík, Petr

2015-04-01

In this paper, issues of agricultural drainage systems are introduced and discussed from the views of their former, current and future roles and functioning in the Czech Republic (CR). A methodologically disparate survey was done on thirty-nine model localities in CR with different intensity and state of land drainage systems, aimed at description of commonly occurred problems and possible adaptations of agricultural drainage as perceived by farmers, land owners, landscape managers or by protective water management. The survey was focused on technical state of drainage, fragmentation of land ownership within drained areas as well as on possible conflicts between agricultural and environmental interests in a landscape. Achieved results confirmed that there is obviously an increasing need to reassess some functions of prevailingly single-purpose agricultural drainage systems. Drainage intensity and detected unfavourable technical state of drainage systems as well as the risks connected with the anticipated climate change from the view of possible water scarcity claims for a complex solution. An array of adaptation options for agricultural drainage systems is presented, aiming at enhancement of water retention time and improvement of water quality. It encompasses additional flow-controlling measures on tiles or ditches, or facilities for making selected parts of a drainage system inoperable in order to retain or slow down the drainage runoff, to establish water accumulation zones and to enhance water self-cleaning processes. However, it was revealed that the question of landowner parcels fragmentation on drained land in CR would dramatically complicate design and realization of these measures. Presented solutions and findings are propounded with a respect to contemporary and future state policies and international strategies for sustainable agriculture, water management and environment.

Blood loss associated with Ring uncemented total knee replacement: comparison between continuous and intermittent suction drainage.

PubMed Central

Wittmann, F W; Ring, P A

1984-01-01

In a retrospective comparison of blood loss following uncemented total knee replacement, in which either continuous or intermittent suction drainage was used, measured blood loss was significantly greater with continuous drainage. However, a method of calculating actual blood loss demonstrated no significant difference. With intermittent drainage, more blood remains undetected around the knee joint; this technique should therefore be abandoned in favour of continuous suction drainage. PMID:6747978

The Soil Foam Drainage Equation - an alternative model for unsaturated flow in porous media

NASA Astrophysics Data System (ADS)

Assouline, Shmuel; Lehmann, Peter; Hoogland, Frouke; Or, Dani

2017-04-01

The analogy between the geometry and dynamics of wet foam drainage and gravity drainage of unsaturated porous media expands modeling capabilities for capillary flows and supplements the standard Richards equation representation. The governing equation for draining foam (or a soil variant termed the soil foam drainage equation - SFDE) obviates the need for macroscopic unsaturated hydraulic conductivity function by an explicit account of diminishing flow pathway sizes as the medium gradually drains. Potential advantages of the proposed drainage foam formalism include direct description of transient flow without requiring constitutive functions; evolution of capillary cross sections that provides consistent description of self-regulating internal fluxes (e.g., towards field capacity); and a more intuitive geometrical picture of capillary flow across textural boundaries. We will present new and simple analytical expressions for drainage rates and volumes from unsaturated porous media subjected to different boundary conditions that are in good agreement with the numerical solution of the SFDE and experimental results. The foam drainage methodology expands the range of tools available for describing and quantifying unsaturated flows and provides geometrically tractable links between evolution of liquid configuration and flow dynamics in unsaturated porous media. The resulting geometrical representation of capillary drainage could improve understanding of colloid and pathogen transport. The explicit geometrical interpretation of flow pathways underlying the hydraulic functions used by the Richards equation offers new insights that benefit both approaches.

Modeling Antarctic Subglacial Lake Filling and Drainage Cycles

NASA Technical Reports Server (NTRS)

Dow, Christine F.; Werder, Mauro A.; Nowicki, Sophie; Walker, Ryan T.

2016-01-01

The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to examine internal controls on the filling and drainage of subglacial lakes. Our model outputs suggest that the highly constricted subglacial environment of our idealized ice stream, combined with relatively high rates of water flow funneled from a large catchment, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water beneath the ice stream drives lake growth. As the water body builds up, it steepens the hydraulic gradient out of the overdeepened lake basin and allows greater flux. Eventually this flux is large enough to melt channels that cause the lake to drain. Lake drainage also depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

Endoscopic Gallbladder Drainage for Acute Cholecystitis

PubMed Central

Widmer, Jessica; Alvarez, Paloma; Sharaiha, Reem Z.; Gossain, Sonia; Kedia, Prashant; Sarkaria, Savreet; Sethi, Amrita; Turner, Brian G.; Millman, Jennifer; Lieberman, Michael; Nandakumar, Govind; Umrania, Hiren; Gaidhane, Monica

2015-01-01

Background/Aims Surgery is the mainstay of treatment for cholecystitis. However, gallbladder stenting (GBS) has shown promise in debilitated or high-risk patients. Endoscopic transpapillary GBS and endoscopic ultrasound-guided GBS (EUS-GBS) have been proposed as safe and effective modalities for gallbladder drainage. Methods Data from patients with cholecystitis were prospectively collected from August 2004 to May 2013 from two United States academic university hospitals and analyzed retrospectively. The following treatment algorithm was adopted. Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and cystic duct stenting was initially attempted. If deemed feasible by the endoscopist, EUS-GBS was then pursued. Results During the study period, 139 patients underwent endoscopic gallbladder drainage. Among these, drainage was performed in 94 and 45 cases for benign and malignant indications, respectively. Successful endoscopic gallbladder drainage was defined as decompression of the gallbladder without incidence of cholecystitis, and was achieved with ERCP and cystic duct stenting in 117 of 128 cases (91%). Successful endoscopic gallbladder drainage was also achieved with EUS-guided gallbladder drainage using transmural stent placement in 11 of 11 cases (100%). Complications occurred in 11 cases (8%). Conclusions Endoscopic gallbladder drainage techniques are safe and efficacious methods for gallbladder decompression in non-surgical patients with comorbidities. PMID:26473125

Transurethral Drainage of Prostatic Abscess: Points of Technique

PubMed Central

El-Shazly, Mohamed; El- Enzy, Nawaf; El-Enzy, Khaled; Yordanov, Encho; Hathout, Badawy; Allam, Adel

2012-01-01

Background The incidence of prostatic abscess (PA) has markedly declined with the widespread use of antibiotics and the decreasing incidence of urethral gonococcal infections. Objectives To evaluate different treatment methods for prostatic abscess and to describe technical points that will improve the outcome of transurethral (TUR) drainage of prostatic abscess. Patients and Methods We performed a retrospective study of a series of 11 patients diagnosed with prostatic abscess, who were admitted and treated in Farwaniya Hospital, Kuwait, between February 2008 and November 2010. Drainage was indicated when antibiotic therapy did not cause clinical improvement and after prostatic abscess was confirmed by TRUS (Transrectal ultrasonography) and/or CT computed Tomographyscan. TUR drainage was indicated in 7 cases, ultrasound-guided transrectal drainage was performed in 2 cases, and ultrasound-guided perineal drainage was performed in 2 cases. Results All patients that underwent TUR-drainage had successful outcomes, without the need of secondary treatment or further surgery. Conclusions TUR drainage of a prostatic abscess increases the likelihood of a successful outcome and lowers the incidence of treatment failure or repeated surgery. Less invasive treatment, with perineal or transrectal aspiration, may be preferred as a primary treatment in relatively young patients with localized abscess cavities. PMID:23573466

Climate and Tectonics Need Not Apply: Transient Erosion Driven by Drainage Integration, Aravaipa Creek, AZ

NASA Astrophysics Data System (ADS)

Jungers, M.; Heimsath, A. M.

2013-12-01

Periods of transient erosion during landscape evolution are most commonly attributed to fluvial systems' responses to changes in tectonic or climatic forcing. Dramatic changes in base level and sudden increases in drainage area associated with drainage reorganization can, however, drive punctuated events of incision and erosion equal in magnitude to those driven by tectonics or climate. In southeastern Arizona's Basin and Range, a mature portion of the North American physiographic province, the modern Gila River system integrates a network of previously internally drained structural basins. One basin in particular, Aravaipa Creek, is the most recent to join the broader Gila River fluvial network. Following drainage integration, Aravaipa Creek rapidly incised to equilibrate with its new, much lower, base level. In doing so, it carved Aravaipa Canyon, excavated a large volume of sedimentary basin fill, and captured drainage area from the still internally drained Sulphur Springs basin. Importantly, this dramatic episode of transient incision and erosion was the result of drainage integration alone. We hypothesize that the adjustment time for Aravaipa Creek was shorter than the timescale of any climate forcing, and regional extensional tectonics were quiescent at the time of integration. We can, therefore, explicitly quantify the magnitude of transient incision and erosion driven by drainage reorganization. We use remnants of the paleo-basin surface and modern landscape elevations to reconstruct the pre-drainage integration topography of Aravaipa Creek basin. Doing so enables us to quantify the magnitude of incision driven by drainage reorganization as well as the volume of material eroded from the basin subsequent to integration. Key control points for our landscape reconstruction are: (1) the inferred elevation of the spillover point between Aravaipa Creek and the San Pedro River; (2) Quaternary pediment-capping gravels above Aravaipa Canyon (3) perched remnants of late stage sedimentary basin fill that preserve the slope of the pre-incision piedmonts of the Galiuro Mountains and Santa Teresa Mountains; and (4) the paleo-drainage divide between Aravaipa Creek and Sulphur Springs Valley, approximately 6 km northwest of the modern divide. The pre-incision basin surface sloped from the Sulphur Springs divide (1370 m) to its intersection with the point of integration (1100 m) between Aravaipa Creek and the San Pedro River, 50 km to the northwest. Maximum incision of 450 m occurred in the vicinity of Aravaipa Canyon, and more than 50 cubic kilometers of material have been eroded from Aravaipa Creek basin. Finally, cosmogenic nuclide burial dates for latest stage sedimentary basin fill enable us to constrain the timing of drainage integration and place first-order constraints on paleo-erosion rates.

Systematic review and meta-analysis of initial management of pneumothorax in adults: Intercostal tube drainage versus other invasive methods

PubMed Central

Park, Incheol; Kim, Kyung Hwan; Park, Junseok; Shin, Dong Wun

2017-01-01

Objectives The ideal invasive management as initial approach for pneumothorax (PTX) is still under debate. The purpose of this systematic review and meta-analysis was to examine the evidence for the effectiveness of intercostal tube drainage and other various invasive methods as the initial approach to all subtypes of PTX in adults. Methods Three databases were searched from inception to May 29, 2016: MEDLINE, EMBASE, and the Cochrane CENTRAL. Randomised controlled trials that evaluated intercostal tube drainage as the control and various invasive methods as the intervention for the initial approach to PTX in adults were included. The primary outcome was the early success rate of each method, and the risk ratios (RRs) were used for an effect size measure. The secondary outcomes were recurrence rate, hospitalization rate, hospital stay, and complications. Results Seven studies met our inclusion criteria. Interventions were aspiration in six studies and catheterization connected to a one-way valve in one study. Meta-analyses were conducted for early success rate, recurrence rate, hospitalization rate, and hospital stay. Aspiration was inferior to intercostal tube drainage in terms of early success rate (RR = 0.82, confidence interval [CI] = 0.72 to 0.95, I2 = 0%). While aspiration and intercostal tube drainage showed no significant difference in the recurrence rate (RR = 0.84, CI = 0.57 to 1.23, I2 = 0%), aspiration had shorter hospital stay than intercostal tube drainage (mean difference = -1.73, CI = -2.33 to -1.13, I2 = 0%). Aspiration had lower hospitalization rate than intercostal tube drainage, but marked heterogeneity was present (RR = 0.38, CI = 0.19 to 0.76, I2 = 85%). Conclusion Aspiration was inferior to intercostal tube drainage in terms of early resolution, but it had shorter hospital stay. The recurrence rate of aspiration and intercostal tube drainage did not differ significantly. The efficacy of catheterization connected to a one-way valve was inconclusive because of the small number of relevant studies. (Registration of study protocol: PROSPERO, CRD42016037866) PMID:28640890

Effects of the inner droplet of double emulsions on the film drainage during a head-on collision

NASA Astrophysics Data System (ADS)

Wang, Jingtao; Jing, Hefeng; Xu, Genmiao; Wang, Xiaoyong; Duan, Zhenya

2015-07-01

As a critical stage which severely affects the final coalescence of droplets, film drainage in the collision process of two simple droplets has been deeply studied for many years. However, the collision of multiple emulsions which contain other phases (like daughter droplets or particles) has never been studied although multiple emulsions are very important in emulsion industries nowadays. In this paper, the head-on collision of two core-shell double emulsions with equal sizes is investigated through a boundary integral method to disclose the effects of the inner droplet on the film drainage. When capillary number Ca is relatively high, due to the effect of the inner droplet on the inner circulation of mother droplets, the film drainage of double emulsions includes three stages: drainage, drainage halt, and second drainage, instead of two stages for that of simple droplets: drainage and drainage halt.

A hierarchical pyramid method for managing large-scale high-resolution drainage networks extracted from DEM

NASA Astrophysics Data System (ADS)

Bai, Rui; Tiejian, Li; Huang, Yuefei; Jiaye, Li; Wang, Guangqian; Yin, Dongqin

2015-12-01

The increasing resolution of Digital Elevation Models (DEMs) and the development of drainage network extraction algorithms make it possible to develop high-resolution drainage networks for large river basins. These vector networks contain massive numbers of river reaches with associated geographical features, including topological connections and topographical parameters. These features create challenges for efficient map display and data management. Of particular interest are the requirements of data management for multi-scale hydrological simulations using multi-resolution river networks. In this paper, a hierarchical pyramid method is proposed, which generates coarsened vector drainage networks from the originals iteratively. The method is based on the Horton-Strahler's (H-S) order schema. At each coarsening step, the river reaches with the lowest H-S order are pruned, and their related sub-basins are merged. At the same time, the topological connections and topographical parameters of each coarsened drainage network are inherited from the former level using formulas that are presented in this study. The method was applied to the original drainage networks of a watershed in the Huangfuchuan River basin extracted from a 1-m-resolution airborne LiDAR DEM and applied to the full Yangtze River basin in China, which was extracted from a 30-m-resolution ASTER GDEM. In addition, a map-display and parameter-query web service was published for the Mississippi River basin, and its data were extracted from the 30-m-resolution ASTER GDEM. The results presented in this study indicate that the developed method can effectively manage and display massive amounts of drainage network data and can facilitate multi-scale hydrological simulations.

Chest tube drainage of pleural effusions--an audit of current practice and complications at Hutt Hospital.

PubMed

Epstein, Erica; Jayathissa, Sisira; Dee, Stephen

2012-05-11

The aims of the study were to review small-bore chest tube insertion practices for drainage of pleural fluid at Hutt Valley District Health Board (HVDHB), to assess complications, and compare the findings with international data. Retrospective analysis of clinical records was completed on all chest tube insertions for drainage of pleural fluid at HVDHB from December 2008 to November 2009. Descriptive statistics were used to present demographics and tube-associated complications. Comparison was made to available similar international data. Small-bore tubes comprised 59/65 (91%) chest tube insertions and 23/25 (92%) complications. Available comparative data was limited. Ultrasound was used in 36% of insertions. Nearly half of chest drains placed for empyema required subsequent cardiothoracic surgical intervention. Chest drain complication rates at HVDHB were comparable to those seen internationally. Referral rates to cardiothoracic surgery for empyema were within described ranges. The importance of procedural training for junior medical staff, optimising safety of drain insertions with ultrasound guidance, and clear clinical governance for chest tube insertions are important in minimising harm from this procedure. Specialist societies need to take a leadership in providing guidance on chest drain insertions to secondary and tertiary hospitals in Australia and New Zealand.

A case of transgastric gallbladder puncture as a complication during endoscopic ultrasound-guided drainage of a pancreatic pseudocyst.

PubMed

Hikichi, Takuto; Irisawa, Atsushi; Takagi, Tadayuki; Shibukawa, Goro; Wakatsuki, Takeru; Imamura, Hidemichi; Takahashi, Yuta; Sato, Ai; Sato, Masaki; Oyama, Hitoshi; Sato, Naoto; Yamamoto, Go; Mokonuma, Tatsuyuki; Obara, Katsutoshi; Ohira, Hiromasa

2007-06-01

A 43-year-old man, a regular drinker, developed a pseudocyst in the pancreatic tail as a result of acutely worsening chronic pancreatitis. Because the pseudocyst, 10 cm in diameter, did not disappear despite conservative treatment, an internal drainage stent was placed transgastrically under endoscopic ultrasound (EUS) guidance. However, cyst infection occurred, and EUS-guided drainage was performed, when the gallbladder was punctured inadvertently. Immediately a nasocystic drain was placed in the gallbladder. Owing to this timely measure, only mild and localized peritonitis developed. Conservative treatment with fasting and an antibiotic was administered, and peritonitis subsided quickly. On the same day, another nasocystic drain was placed for the pancreatic pseudocyst, and it disappeared. As far as we know, this is the first case in which gallbladder puncture was inadvertently performed during EUS-guided drainage of a pancreatic pseudocyst.

Greenhouse gas emissions from integrated urban drainage systems: Where do we stand?

NASA Astrophysics Data System (ADS)

Mannina, Giorgio; Butler, David; Benedetti, Lorenzo; Deletic, Ana; Fowdar, Harsha; Fu, Guangtao; Kleidorfer, Manfred; McCarthy, David; Steen Mikkelsen, Peter; Rauch, Wolfgang; Sweetapple, Chris; Vezzaro, Luca; Yuan, Zhiguo; Willems, Patrick

2018-04-01

As sources of greenhouse gas (GHG) emissions, integrated urban drainage systems (IUDSs) (i.e., sewer systems, wastewater treatment plants and receiving water bodies) contribute to climate change. This paper, produced by the International Working Group on Data and Models, which works under the IWA/IAHR Joint Committee on Urban Drainage, reviews the state-of-the-art and modelling tools developed recently to understand and manage GHG emissions from IUDS. Further, open problems and research gaps are discussed and a framework for handling GHG emissions from IUDSs is presented. The literature review reveals that there is a need to strengthen already available mathematical models for IUDS to take GHG into account.

NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

NASA Technical Reports Server (NTRS)

Horne, W. B.

1977-01-01

Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

Negative pressure irrigation and endoscopic necrosectomy through man-made sinus tract in infected necrotizing pancreatitis: a technical report.

PubMed

Tong, Zhihui; Ke, Lu; Li, Baiqiang; Li, Gang; Zhou, Jing; Shen, Xiao; Li, Weiqin; Li, Ning; Li, Jieshou

2016-11-10

In recent years, a step-up approach based on minimally invasive techniques was recommended by latest guidelines as initial invasive treatment for infected pancreatic necrosis (IPN). In this study, we aimed to describe a novel step-up approach for treating IPN consisting of four steps including negative pressure irrigation (NPI) and endoscopic necrosectomy (ED) as a bridge between percutaneous catheter drainage (PCD) and open necrosectomy METHODS: A retrospective review of a prospectively collected internal database of patients with a diagnosis of IPN between Jan, 2012 to Dec, 2012 at a single institution was performed. All patients underwent the same drainage strategy including four steps: PCD, NPI, ED and open necrosectomy. The demographic characteristics and clinical outcomes of study patients were analyzed. A total of 71 consecutive patients (48 males and 23 females) were included in the analysis. No significant procedure-related complication was observed and the overall mortality was +21.1 % (15 of 71 patients). Seven different strategies like PCD+ NPI, PCD+NPI+ED, PCD+open necrosectomy, etcetera, were applied in study patients and a half of them received PCD alone. In general, each patient underwent a median of 2 drainage procedures and the median total drainage duration was 11 days (interquartile range, 6-21days). This four-step approach is effective in treating IPN and adds no extra risk to patients when compared with other latest step-up strategies. The two novel techniques (NPI and ED) could offer distinct clinical benefits without posing unanticipated risks inherent to the procedures.

Automatic Generalizability Method of Urban Drainage Pipe Network Considering Multi-Features

NASA Astrophysics Data System (ADS)

Zhu, S.; Yang, Q.; Shao, J.

2018-05-01

Urban drainage systems are indispensable dataset for storm-flooding simulation. Given data availability and current computing power, the structure and complexity of urban drainage systems require to be simplify. However, till data, the simplify procedure mainly depend on manual operation that always leads to mistakes and lower work efficiency. This work referenced the classification methodology of road system, and proposed a conception of pipeline stroke. Further, length of pipeline, angle between two pipelines, the pipeline belonged road level and diameter of pipeline were chosen as the similarity criterion to generate the pipeline stroke. Finally, designed the automatic method to generalize drainage systems with the concern of multi-features. This technique can improve the efficiency and accuracy of the generalization of drainage systems. In addition, it is beneficial to the study of urban storm-floods.

Correlations between anomalies of jugular veins and areas of vascular drainage of head and neck.

PubMed

Vaida, Monica-Adriana; Niculescu, V; Motoc, A; Bolintineanu, S; Sargan, Izabella; Niculescu, M C

2006-01-01

The study conducted on 60 human cadavers preserved in formalin, in the Anatomy Laboratory of the "Victor Babes" University of Medicine and Pharmacy Timisoara, during 2000-2006, observed the internal and external jugular veins from the point of view of their origin, course and affluents. The morphological variability of the jugular veins (external jugular that receives as affluents the facial and lingual veins and drains into the internal jugular, draining the latter's territory--3.33%; internal jugular that receives the lingual, upper thyroid and facial veins, independent--13.33%, via the linguofacial trunk--50%, and via thyrolinguofacial trunk--33.33%) made possible the correlation of these anomalies with disorders in the ontogenetic development of the veins of the neck. Knowing the variants of origin, course and drainage area of jugular veins is important not only for the anatomist but also for the surgeon operating at this level.

[Inflammatory and infectious breast mastitis outside of pregnancy and lactation: Guidelines].

PubMed

Laas, E; Touboul, C; Kerdraon, O; Catteau-Jonard, S

2015-12-01

This work's objective was to define the various non-cancerous inflammatory and infectious mastitis, which may occur outside of pregnancy and lactation, and to identify recommendations for their care based on an exhaustive literature review. A literature review was conducted by consulting Medline, Cochrane Library, Google scholar and international recommendations in French and English until 31st August 2014. Infectious mastitis (periareolar abscess) is the most common form of non-puerperal abscesses and it is recommended that a suction/drainage needle for abscesses under 5 cm, involving antibiotic therapy (grade C). For abscesses over 5 cm, there is no evidence to recommend a first surgery or suction/drainage. Inflammatory mastitis can be primary or secondary to a systemic disease (diabetes, collagen…; LE4). In case of idiopathic granulomatous mastitis, a steroid therapy or surgery may be indicated, without one or the other of these methods can be recommended. In case of plasma cell mastitis or ductal ectasia, no treatment is recommended. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Lap-Protector and Circular Stapler Are Useful in Cystogastrostomy for Large Pancreatic Pseudocyst with Severe Infection

PubMed Central

Kadowaki, Yoshihiko; Kurokawa, Takefumi; Tamura, Ryuji; Okamoto, Takahiro; Ishido, Nobuhiro; Mori, Takashi

2010-01-01

Lap-Protector, which is an abdominal wall sealing device, is usually used for wound protection from implantation of malignant cells or pyogenic fluid. A circular stapler is a common easy-to-use device for anastomosis of the digestive tract. We report the case of an infected pancreatic pseudocyst which was treated by surgical procedure using these useful devices. A 69-year-old man was followed up in our hospital after severe acute pancreatitis. He had undergone drainage surgeries twice for intractable pancreatic abscess followed by severe acute pancreatitis. He was admitted to our hospital complaining of loss of appetite, hiccups, and high fever. Computed tomography of the abdomen revealed an infected pancreatic pseudocyst which compressed the gastric wall. Internal drainage into the stomach was performed using Lap-Protector and circular stapler. The patient recovered uneventfully. Recently many endoscopic or laparoscopic procedures in cystogastrostomy are reported; however, a conventional open surgical approach is also important. This easy method may be useful for operative cystogastrostomy. PMID:20805947

Extraction of drainage networks from large terrain datasets using high throughput computing

NASA Astrophysics Data System (ADS)

Gong, Jianya; Xie, Jibo

2009-02-01

Advanced digital photogrammetry and remote sensing technology produces large terrain datasets (LTD). How to process and use these LTD has become a big challenge for GIS users. Extracting drainage networks, which are basic for hydrological applications, from LTD is one of the typical applications of digital terrain analysis (DTA) in geographical information applications. Existing serial drainage algorithms cannot deal with large data volumes in a timely fashion, and few GIS platforms can process LTD beyond the GB size. High throughput computing (HTC), a distributed parallel computing mode, is proposed to improve the efficiency of drainage networks extraction from LTD. Drainage network extraction using HTC involves two key issues: (1) how to decompose the large DEM datasets into independent computing units and (2) how to merge the separate outputs into a final result. A new decomposition method is presented in which the large datasets are partitioned into independent computing units using natural watershed boundaries instead of using regular 1-dimensional (strip-wise) and 2-dimensional (block-wise) decomposition. Because the distribution of drainage networks is strongly related to watershed boundaries, the new decomposition method is more effective and natural. The method to extract natural watershed boundaries was improved by using multi-scale DEMs instead of single-scale DEMs. A HTC environment is employed to test the proposed methods with real datasets.

The operating surgeon is an independent predictor of chest tube drainage following cardiac surgery.

PubMed

Dixon, Barry; Reid, David; Collins, Marnie; Newcomb, Andrew E; Rosalion, Alexander; Yap, Cheng-Hon; Santamaria, John D; Campbell, Duncan J

2014-04-01

Bleeding into the chest is a major cause of blood transfusion and adverse outcomes following cardiac surgery. The authors investigated predictors of bleeding following cardiac surgery to identify potentially correctable factors. Data were retrieved from the medical records of patients undergoing cardiac surgery over the period of 2002 to 2008. Multivariate analysis was used to identify the independent predictors of chest tube drainage. Tertiary hospital. Two thousand five hundred seventy-five patients. Cardiac surgery. The individual operating surgeon was independently associated with the extent of chest tube drainage. Other independent factors included internal mammary artery grafting, cardiopulmonary bypass time, urgency of surgery, tricuspid valve surgery, redo surgery, left ventricular impairment, male gender, lower body mass index and higher preoperative hemoglobin levels. Both a history of diabetes and administration of aprotinin were associated with reduced levels of chest tube drainage. The individual operating surgeon was an independent predictor of the extent of chest tube drainage. Attention to surgeon-specific factors offers the possibility of reduced bleeding, fewer transfusions, and improved patient outcomes. © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Simulation of streamflow in small drainage basins in the southern Yampa River basin, Colorado

USGS Publications Warehouse

Parker, R.S.; Norris, J.M.

1989-01-01

Coal mining operations in northwestern Colorado commonly are located in areas that have minimal available water-resource information. Drainage-basin models can be a method for extending water-resource information to include periods for which there are no records or to transfer the information to areas that have no streamflow-gaging stations. To evaluate the magnitude and variability of the components of the water balance in the small drainage basins monitored, and to provide some method for transfer of hydrologic data, the U.S. Geological Survey 's Precipitation-Runoff Modeling System was used for small drainage basins in the southern Yampa River basin to simulate daily mean streamflow using daily precipitation and air-temperature data. The study area was divided into three hydrologic regions, and in each of these regions, three drainage basins were monitored. Two of the drainage basins in each region were used to calibrate the Precipitation-Runoff Modeling System. The model was not calibrated for the third drainage basin in each region; instead, parameter values were transferred from the model that was calibrated for the two drainage basins. For all of the drainage basins except one, period of record used for calibration and verification included water years 1976-81. Simulated annual volumes of streamflow for drainage basins used in calibration compared well with observed values; individual hydrographs indicated timing differences between the observed and simulated daily mean streamflow. Observed and simulated annual average streamflows compared well for the periods of record, but values of simulated high and low streamflows were different than observed values. Similar results were obtained when calibrated model parameter values were transferred to drainage basins that were uncalibrated. (USGS)

Storm water runoff measurements of copper from a naturally patinated roof and from a parking space. Aspects on environmental fate and chemical speciation.

PubMed

Odnevall Wallinder, I; Hedberg, Y; Dromberg, P

2009-12-01

Release of copper from a naturally aged copper roof on a shopping centre building in a suburban site of Stockholm has been measured during different rain events after its interaction with the internal drainage system and storm drains made of cast iron and concrete. Concentrations of copper removed by means of urban storm water from a nearby parking space have been determined for comparison. Predictions and measurements of the chemical speciation of released copper are discussed compared to the total concentration, and to threshold values for freshwater and drinking water. The results clearly illustrate that the major part of the released copper from the roof is readily retained already during transport through the internal drainage system of the building, a pathway that also changes the chemical speciation of released copper and its bioavailable fraction. Most copper, not retained by cast iron and concrete surfaces, was strongly complexed to organic matter. The median concentration of free cupric ions and weak copper complexes was less than, or within the range of reported no effect concentrations, NOECs, of copper in surface waters. The parking space contributed with significantly higher and time-dependent concentrations of total copper compared to measured concentrations of copper from the roof after the interaction with the drainage system. Most copper in the surface runoff water was strongly complexed with organic matter, hence reducing the bioavailable fraction significantly to concentrations within the NOEC range. Dilution with other sources of urban storm water will reduce the released concentration of copper even further. The results illustrate that already the internal drainage system and the storm drains made of cast iron and concrete act as efficient sinks for released copper which means that any installation of additional infiltration devices is redundant.

Proximal lava drainage controls on basaltic fissure eruption dynamics

NASA Astrophysics Data System (ADS)

Jones, T. J.; Llewellin, E. W.; Houghton, B. F.; Brown, R. J.; Vye-Brown, C.

2017-11-01

Hawaiian basaltic eruptions commonly initiate as a fissure, producing fountains, spattering, and clastogenic lava flows. Most fissures rapidly localize to form a small number of eruptive vents, the location of which may influence the subsequent distribution of lava flows and associated hazards. We present results from a detailed field investigation of the proximal deposits of episode 1 of the 1969 fissure eruption of Mauna Ulu, Kīlauea, Hawai`i. Exceptional preservation of the deposits allows us to reconstruct vent-proximal lava drainage patterns and to assess the role that drainage played in constraining vent localization. Through detailed field mapping, including measurements of the height and internal depth of lava tree moulds, we reconstruct high-resolution topographic maps of the pre-eruption ground surface, the lava high-stand surface and the post-eruption ground surface. We calculate the difference in elevation between pairs of maps to estimate the lava inundation depth and lava drainage depth over the field area and along different segments of fissure. Aerial photographs collected during episode 1 of the eruption allow us to locate those parts of the fissure that are no longer exposed at the surface. By comparing with the inundation and drainage maps, we find that fissure segments that were inundated with lava to greater depths (typically 1-6 m) during the eruption later became foci of lava drainage back into the fissure (internal drain-back). We infer that, in these areas, lava ponding over the fissure suppressed discharge of magma, thereby favouring drain-back and stagnation. By contrast, segments with relatively shallow inundation (typically less than 1 m), such as where the fissure intersects pre-eruptive topographic highs, or where flow away from the vent (outflow) was efficient, are often associated with sub-circular vent geometries in the post-eruption ground surface. We infer that these parts of the fissure became localization points for ongoing magma ascent and discharge. We conclude that lava inundation and drainage processes in basaltic fissure eruptions can play an important role in controlling their localization and longevity.

Effective and efficient agricultural drainage pipe mapping with UAS thermal infrared imagery: a case study

USDA-ARS?s Scientific Manuscript database

Effective and efficient methods are needed to map agricultural subsurface drainage systems. Visible (VIS), near infrared (NIR), and/or thermal infrared (TIR) imagery obtained by unmanned aircraft systems (UAS) may provide a means for determining drainage pipe locations. Preliminary UAS surveys wit...

Estimating design discharges for drainage structures in western Kansas.

DOT National Transportation Integrated Search

2013-06-01

KDOT engineers have expressed concern that the hydrologic methods in the current KDOT Design Manual (Volume I, : Part C, 2011) may lead to over-sizing of drainage structures in Western Kansas. Some new structures designed by the current : methods are...

High-efficient Extraction of Drainage Networks from Digital Elevation Model Data Constrained by Enhanced Flow Enforcement from Known River Map

NASA Astrophysics Data System (ADS)

Wu, T.; Li, T.; Li, J.; Wang, G.

2017-12-01

Improved drainage network extraction can be achieved by flow enforcement whereby information of known river maps is imposed to the flow-path modeling process. However, the common elevation-based stream burning method can sometimes cause unintended topological errors and misinterpret the overall drainage pattern. We presented an enhanced flow enforcement method to facilitate accurate and efficient process of drainage network extraction. Both the topology of the mapped hydrography and the initial landscape of the DEM are well preserved and fully utilized in the proposed method. An improved stream rasterization is achieved here, yielding continuous, unambiguous and stream-collision-free raster equivalent of stream vectors for flow enforcement. By imposing priority-based enforcement with a complementary flow direction enhancement procedure, the drainage patterns of the mapped hydrography are fully represented in the derived results. The proposed method was tested over the Rogue River Basin, using DEMs with various resolutions. As indicated by the visual and statistical analyses, the proposed method has three major advantages: (1) it significantly reduces the occurrences of topological errors, yielding very accurate watershed partition and channel delineation, (2) it ensures scale-consistent performance at DEMs of various resolutions, and (3) the entire extraction process is well-designed to achieve great computational efficiency.

Drainage reorganization and divide migration induced by the excavation of the Ebro basin (NE Spain)

NASA Astrophysics Data System (ADS)

Vacherat, Arnaud; Bonnet, Stéphane; Mouthereau, Frédéric

2018-05-01

Intracontinental endorheic basins are key elements of source-to-sink systems as they preserve sediments eroded from the surrounding catchments. Drainage reorganization in such a basin in response to changing boundary conditions has strong implications on the sediment routing system and on landscape evolution. The Ebro and Duero basins represent two foreland basins, which developed in response to the growth of surrounding compressional orogens, the Pyrenees and the Cantabrian mountains to the north, the Iberian Ranges to the south, and the Catalan Coastal Range to the east. They were once connected as endorheic basins in the early Oligocene. By the end of the Miocene, new post-orogenic conditions led to the current setting in which the Ebro and Duero basins are flowing in opposite directions, towards the Mediterranean Sea and the Atlantic Ocean. Although these two hydrographic basins recorded a similar history, they are characterized by very different morphologic features. The Ebro basin is highly excavated, whereas relicts of the endorheic stage are very well preserved in the Duero basin. The contrasting morphological preservation of the endorheic stage represents an ideal natural laboratory to study the drivers (internal and/or external) of post-orogenic drainage divide mobility, drainage network, and landscape evolution. To that aim, we use field and map observations and we apply the χ analysis of river profiles along the divide between the Ebro and Duero drainage basins. We show here that the contrasting excavation of the Ebro and Duero basins drives a reorganization of their drainage network through a series of captures, which resulted in the southwestward migration of their main drainage divide. Fluvial captures have a strong impact on drainage areas, fluxes, and their respective incision capacity. We conclude that drainage reorganization driven by the capture of the Duero basin rivers by the Ebro drainage system explains the first-order preservation of endorheic stage remnants in the Duero basin, due to drainage area loss, independently from tectonics and climate.

[Circular transhepatic drainage as a palliative surgical measure in central bile duct obstruction].

PubMed

Neugebauer, W; Durst, J; Koslowski, L

1979-10-01

A transhepatic drainage tube was used in 27 patients suffering from echinococcus alveolaris of the liver of malignant process of the portal fissure from 1967 to 1978. If an hepatocholangioenterostomy is not possible, another surgical palliative procedure is necessary for drainage of the bile. The transhepatic drainage tube is a simple palliative method. The technique of this procedure, the indications, the possible complications, and the advantages are reported.

[Internal drainage in cancer patients: optimizing treatment of stent-related symptoms].

PubMed

Martov, A G; Ergakov, D V; Novikov, A B; Muzhetskaya, N G; Esen'yan, G L

2016-04-01

The so-called stent-related symptoms caused mainly by detrusor overactivity due to distal ("cystic") curl of the internal stent are common among patients with this type of drainage. The need for long-term stenting makes the quality of life of cancer patients one of the challenging problems of modern urology. The aim of this study was to optimize treatment of stent-related symptoms in cancer patients with internal long-term stents by complementing the treatment regimen with m-anticholinergic solifenacin. From November 2013 to November 2015 68 cancer patients (26 males, 42 females, age 36-79 years) underwent elective internal ureteral stenting for drainage of the upper urinary tract (UUT) with special long-term stents coated with the hydrogel. The urinary tract obstruction was caused by urological (24), gynecological (26) and colorectal (18) cancers. Before deciding on urinary tract drainage, all patients were treated with radiation or chemotherapy, 28 (41.2%) patients underwent surgery, but on admission all of them had contraindications to radical surgery for different reasons. In 52 (76.5%) patients UUT stenting was performed using transurethral access, in 12 (17.6%) by percutaneous access and in another 4 (5.9%) by the combined access with patients in the supine position. Percutaneous and combined access was used in cases of impracticability (failure) of transurethral stenting. Patients in group 1 (n=32) after stent placement received standard therapy co-administered with solifenacin 5 mg daily, group 2 (n=36) - only standard therapy. The data analyzed were the technical features of the internal drainage, optimal access and registered solifenacin-related adverse events. Control examinations were scheduled once in 3 months after stent placement according to the following algorithm: ultrasound scanning, laboratory test monitoring and, if indicated, plain urography. To objectify the severity of stent-related symptoms, a survey of patients using a special questionnaire was conducted. Visual analog scale was used to measure subjectively the patients condition. After 12 months only 48 patients (26 from group 1 and 22 from group 2) completed the study. Follow-up examinations revealed that the patients in group 1 had significantly lower score of stent-related symptom severity and better ratings in visual analog scale. The greatest difference (1-2 points) was found in urgency and urinary frequency scores. The safety profile of solifenacin 5 mg corresponded to the findings of previous studies, there was no serious adverse events requiring discontinuation of the drug. Installing internal stents in UUT in cancer patients requires relevant experience in Roentgen-endoscopic operations using transurethral and percutaneous approaches and special equipment. In most cases, for preventing and eliminating supravesical obstruction in cancer patients, special internal stents for the long term placement are required. The add-on solifenacin therapy 5 mg/day resulted in almost 20% reduction in the severity of stent-related irritative symptoms and improved the quality of life in this extremely challenging category of patients.

Randomised clinical trial of chest drainage systems.

PubMed Central

Graham, A N; Cosgrove, A P; Gibbons, J R; McGuigan, J A

1992-01-01

BACKGROUND: Problems in the management of thoracic trauma have stimulated the search for an alternative to underwater seals for drainage of the pleural cavity. A chest drainage bag incorporating a one way flutter valve has been compared with underwater seal drains in a randomised clinical trial. METHODS: During June-December 1989 119 patients undergoing elective thoracotomy were randomised to receive postoperative chest drainage by drainage bags (56 patients, 87 drains) or by underwater seal drains (63 patients, 98 drains). Daily drainage volumes, the requirement for pleural suction, mobility, and complications were recorded prospectively. RESULTS: There was no significant difference between the two groups in the mean volume drained, the requirements for pleural suction, or the occurrence of complications. Patients with drainage bags were fully mobile 23 hours (95% confidence interval 0-47 hours) earlier than the others. CONCLUSIONS: When used after elective thoracotomy drainage bags are safe and effective and permit earlier mobility than underwater seal drains. PMID:1496507

Evaluation of urban drainage network based geographycal information system (GIS) in Sumenep City

NASA Astrophysics Data System (ADS)

Agrianto, F.; Hadiani, R.; Purwana, Y. M.

2017-02-01

Sumenep City frequently hit by floods. Drainage network conditions greatly affect the performance of her maid, especially those aspects that affect the capacity of the drainage channel. Aspects that affect the capacity of the drainage channel in the form of sedimentation rate and complementary buildings on drainage channels, for example, the presence of street inlet and trash rack. The method used is a drainage channel capacity level approach that level assessment of each segment drainage network conditions by calculating the ratio of the channel cross-sectional area that is filled with sediment to the total cross-sectional area wet and the existence of complementary buildings. Having obtained the condition index value of each segment, the subsequent analysis is spatial analysis using ArcGIS applications to obtain a map of the drainage network information. The analysis showed that the level condition of drainage network in the city of Sumenep in 2016 that of the total 428 drainage network there are 43 sections belonging to the state level “Good”, 198 drainage network belong to the state level “Enough”, 115 drainage network belong to the state “Mild Damaged”, 50 sections belonging to the state “Heavy Damage” and 22 drainage network belong to the state of “Dysfunction”.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: STORMWATER SOURCE AREA TREATMENT DEVICE: HYDRO INTERNATIONAL DOWNSTREAM DEFENDER®

EPA Science Inventory

Verification testing of the Hydro International Downstream Defender® was conducted at the Madison Water Utility in Madison, Wisconsin. The system was designed for a drainage basin estimated at 1.9 acres in size, but during intense storm events, the system received water from an a...

Temporal and spatial patterns of internal phosphorus recycling in a South Florida (USA) stormwater treatment area

EPA Science Inventory

Large constructed wetlands, known as stormwater treatment areas (STAs), have been deployed to remove phosphorus (P) in drainage waters before discharge into the Everglades in South Florida, USA. Their P removal performance depends on internal P cycling under typically hydrated, b...

Effect of abdominopelvic abscess drain size on drainage time and probability of occlusion

PubMed Central

Rotman, Jessica A.; Getrajdman, George I.; Maybody, Majid; Erinjeri, Joseph P.; Yarmohammadi, Hooman; Sofocleous, Constantinos T.; Solomon, Stephen B.; Boas, F. Edward

2016-01-01

Background The purpose of this study is to determine whether larger abdominopelvic abscess drains reduce the time required for abscess resolution, or the probability of tube occlusion. Methods 144 consecutive patients who underwent abscess drainage at a single institution were reviewed retrospectively. Results: Larger initial drain size did not reduce drainage time, drain occlusion, or drain exchanges (p>0.05). Subgroup analysis did not find any type of collection that benefitted from larger drains. A multivariate model predicting drainage time showed that large collections (>200 ml) required 16 days longer drainage time than small collections (<50 ml). Collections with a fistula to bowel required 17 days longer drainage time than collections without a fistula. Initial drain size and the viscosity of the fluid in the collection had no significant effect on drainage time in the multivariate model. Conclusions 8 F drains are adequate for initial drainage of most serous and serosanguineous collections. 10 F drains are adequate for initial drainage of most purulent or bloody collections. PMID:27634422

Estimating design discharges for drainage structures in western Kansas : [summary].

DOT National Transportation Integrated Search

2013-06-01

KDOT engineers have expressed concern that the hydrologic methods in the current KDOT Design Manual (Volume I, Part C, 2011) may lead to over-sizing of drainage structures in Western Kansas. Some new structures designed by the current methods are muc...

MRI Evidence for Altered Venous Drainage and Intracranial Compliance in Mild Traumatic Brain Injury

PubMed Central

Pomschar, Andreas; Koerte, Inga; Lee, Sang; Laubender, Ruediger P.; Straube, Andreas; Heinen, Florian; Ertl-Wagner, Birgit; Alperin, Noam

2013-01-01

Purpose To compare venous drainage patterns and associated intracranial hydrodynamics between subjects who experienced mild traumatic brain injury (mTBI) and age- and gender-matched controls. Methods Thirty adult subjects (15 with mTBI and 15 age- and gender-matched controls) were investigated using a 3T MR scanner. Time since trauma was 0.5 to 29 years (mean 11.4 years). A 2D-time-of-flight MR-venography of the upper neck was performed to visualize the cervical venous vasculature. Cerebral venous drainage through primary and secondary channels, and intracranial compliance index and pressure were derived using cine-phase contrast imaging of the cerebral arterial inflow, venous outflow, and the craniospinal CSF flow. The intracranial compliance index is the defined as the ratio of maximal intracranial volume and pressure changes during the cardiac cycle. MR estimated ICP was then obtained through the inverse relationship between compliance and ICP. Results Compared to the controls, subjects with mTBI demonstrated a significantly smaller percentage of venous outflow through internal jugular veins (60.9±21% vs. controls: 76.8±10%; p = 0.01) compensated by an increased drainage through secondary veins (12.3±10.9% vs. 5.5±3.3%; p<0.03). Mean intracranial compliance index was significantly lower in the mTBI cohort (5.8±1.4 vs. controls 8.4±1.9; p<0.0007). Consequently, MR estimate of intracranial pressure was significantly higher in the mTBI cohort (12.5±2.9 mmHg vs. 8.8±2.0 mmHg; p<0.0007). Conclusions mTBI is associated with increased venous drainage through secondary pathways. This reflects higher outflow impedance, which may explain the finding of reduced intracranial compliance. These results suggest that hemodynamic and hydrodynamic changes following mTBI persist even in the absence of clinical symptoms and abnormal findings in conventional MR imaging. PMID:23405151

Novel Split Chest Tube Improves Post-Surgical Thoracic Drainage

PubMed Central

Olivencia-Yurvati, Albert H; Cherry, Brandon H; Gurji, Hunaid A; White, Daniel W; Newton, J Tyler; Scott, Gary F; Hoxha, Besim; Gourlay, Terence; Mallet, Robert T

2014-01-01

Objective Conventional, separate mediastinal and pleural tubes are often inefficient at draining thoracic effusions. Description We developed a Y-shaped chest tube with split ends that divide within the thoracic cavity, permitting separate intrathoracic placement and requiring a single exit port. In this study, thoracic drainage by the split drain vs. that of separate drains was tested. Methods After sternotomy, pericardiotomy, and left pleurotomy, pigs were fitted with separate chest drains (n=10) or a split tube prototype (n=9) with internal openings positioned in the mediastinum and in the costo-diaphragmatic recess. Separate series of experiments were conducted to test drainage of D5W or 0.58 M sucrose, an aqueous solution with viscosity approximating that of plasma. One litre of fluid was infused into the thorax, and suction was applied at −20 cm H2O for 30 min. Results When D5W was infused, the split drain left a residual volume of 53 ± 99 ml (mean value ± SD) vs. 148 ± 120 for the separate drain (P=0.007), representing a drainage efficiency (i.e. drained vol/[drained + residual vol]) of 95 ± 10% vs. 86 ± 12% for the separate drains (P = 0.011). In the second series, the split drain evacuated more 0.58 M sucrose in the first minute (967 ± 129 ml) than the separate drains (680 ± 192 ml, P<0.001). By 30 min, the split drain evacuated a similar volume of sucrose vs. the conventional drain (1089 ± 72 vs. 1056 ± 78 ml; P = 0.5). Residual volume tended to be lower (25 ± 10 vs. 62 ± 72 ml; P = 0.128) and drainage efficiency tended to be higher (98 ± 1 vs. 95 ± 6%; P = 0.111) with the split drain vs. conventional separate drains. Conclusion The split chest tube drained the thoracic cavity at least as effectively as conventional separate tubes. This new device could potentially alleviate postoperative complications. PMID:25478289

Development of Urban Inundation Warning Model at Cyclic Artificial Water Way in Song-do International City, Republic of Korea

NASA Astrophysics Data System (ADS)

Lee, T.; Lee, C.; Kim, H.

2016-12-01

Abstract Song-do international city was constructed by reclaiming land from the coastal waters of Yeonsu-gu, Incheon Metropolitan City, Republic of Korea. The □-shaped cyclic artificial water way has been considered for improving water quality, waterfront and internal drainage in Song-do international city. By improving water quality, various marine facilities, such as marina, artificial beach, marine terminal, and so on, will be set up around the artificial water way for the waterfront. Since the water stage of the artificial water way changes depending on water gates operations, it is necessary to develop an urban inundation warning model to evaluate safeties of the waterfront facilities and its passengers. By considering characteristics of urban watershed, we calculate discharge flowing into the water way using XP-SWMM model. As a result of estimating 100-year flood frequency, although there are slight differences in drainage sections, the maximum flood discharge occurs in 90-min rainfall duration. In order to consider impacts of tide and hydraulic structure, we establish Inland drainage plans through the analysis of unsteady flow using HEC-RAS. The urban inundation warning model is configured to issue a warning when the water plain elevation exceeds EL. 1.5m which is usually managed at EL. 1.0m. In this study, the design flood stage of artificial water way and urban inundation warning model are developed for Song-do international city, and therefore it is expected that a reliability of management and operation of the waterfront facilities is improved. Keywords : Artificial Water Way; Waterfront; Urban Inundation Warning Model. Acknowlegement This research was supported by a grant [MPSS-NH-2015-79] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

Systematic review and meta-analysis of initial management of pneumothorax in adults: Intercostal tube drainage versus other invasive methods.

PubMed

Kim, Min Joung; Park, Incheol; Park, Joon Min; Kim, Kyung Hwan; Park, Junseok; Shin, Dong Wun

2017-01-01

The ideal invasive management as initial approach for pneumothorax (PTX) is still under debate. The purpose of this systematic review and meta-analysis was to examine the evidence for the effectiveness of intercostal tube drainage and other various invasive methods as the initial approach to all subtypes of PTX in adults. Three databases were searched from inception to May 29, 2016: MEDLINE, EMBASE, and the Cochrane CENTRAL. Randomised controlled trials that evaluated intercostal tube drainage as the control and various invasive methods as the intervention for the initial approach to PTX in adults were included. The primary outcome was the early success rate of each method, and the risk ratios (RRs) were used for an effect size measure. The secondary outcomes were recurrence rate, hospitalization rate, hospital stay, and complications. Seven studies met our inclusion criteria. Interventions were aspiration in six studies and catheterization connected to a one-way valve in one study. Meta-analyses were conducted for early success rate, recurrence rate, hospitalization rate, and hospital stay. Aspiration was inferior to intercostal tube drainage in terms of early success rate (RR = 0.82, confidence interval [CI] = 0.72 to 0.95, I2 = 0%). While aspiration and intercostal tube drainage showed no significant difference in the recurrence rate (RR = 0.84, CI = 0.57 to 1.23, I2 = 0%), aspiration had shorter hospital stay than intercostal tube drainage (mean difference = -1.73, CI = -2.33 to -1.13, I2 = 0%). Aspiration had lower hospitalization rate than intercostal tube drainage, but marked heterogeneity was present (RR = 0.38, CI = 0.19 to 0.76, I2 = 85%). Aspiration was inferior to intercostal tube drainage in terms of early resolution, but it had shorter hospital stay. The recurrence rate of aspiration and intercostal tube drainage did not differ significantly. The efficacy of catheterization connected to a one-way valve was inconclusive because of the small number of relevant studies. (Registration of study protocol: PROSPERO, CRD42016037866).

The application of peritoneal drainage in the surgical treatment for neonates with necrotizing enterocolitis

NASA Astrophysics Data System (ADS)

Zhao, Jixue; Fu, Xin

2017-08-01

Object To explore the feasibility and effects of peritoneal drainage in the surgical treatment for the neonates with necrotizing enterocolitis. Methods: A retrospective analysis was conduct on 32 cases of newborns with extensive and multiple intestinal necrosis found intraoperatively, all of which could not accept first-stage resected, treated by traditional operation or by peritoneal drainage between January, 2013 to January 2017. Duration of operation, amount of bleeding, and the survival rate after operation were compared between the two groups, which were divided by surgical methods. Results: No significant difference was observed in age, and gender (P>0.05) between the two groups. However, duration of operation was significantly shorter, the amount of bleeding was significantly lessen, the survival rate was significantly higher in the patients by peritoneal drainage than the patients by traditional operation (P<0.05). Conclusion: To compare traditional operation or peritoneal drainage in neonates, a retrospective analysis conducted by us showed the feasibility and effects of peritoneal drainage in neonates, and a significant advantage in duration of operation and the survival rate after operation.

[Choice of an upper urinary tract drainage method in urolithiasis].

PubMed

Doronchuk, D N; Trapeznikova, M F; Dutov, V V

2010-01-01

We made a retrospective (290) and a prospective (131) analysis of the evidence obtained on 421 patients with nephrostomic drainage (251) and an ureteral stent (170) treated for urolithiasis in the urological department of the Moscow Regional Research Clinical Institute from 1995 to 2008. Assessment of clinical and laboratory characteristics of the patients with nephrostomic drainage and an ureteral stent allowed the following conclusions: puncture nephrostomy (p < 0.05) for upper urinary tract drainage is preferable in a solitary functioning kidney, acute obstructive pyelonephritis, anuria, hyperthermia 380 and higher, marked supravesical urodynamic disorder, renal failure, plasmic creatinine level over 200 mcmol/l, azotemia over 10 mmol/l, blood potassium over 5.0 mmol/l, uric acid over 380 mcmol/l and leukocytosis over 8.0 x 10(9)/l. In the other cases a drainage method can be chosen by a physician. Cephalosporines, aminoglycosides, fluoroquinolones and carbapenems in standard doses are recommended in active inflammation when antibioticograms are not obtained yet. Significant differences are seen in drainage with nephrostoma and ureteral stent. Recommendations on nephrostomic drain and ureteral stent installation depending on clinical and laboratory findings are presented.

Descriptive Summary of Patients Seen at the Surgical Companies During Operation Iraqi Freedom-1

DTIC Science & Technology

2004-12-07

4 4 Tissue resection 2 1 3 Vascular shunt 2 2 Chest tube placement 1 1 Cholecystectomy 1 1 Cystostomy 1 1 Decompression craniotomy 1...debridement of his wounds and an open reduction internal fixation of his fracture. On 16 April, the patient developed purulent drainage of his wound and...went back to the operating room for another irrigation and debridement and placement of antibiotic beads. On 22 April, he had further drainage of his

Initial Australasian experience with portal-enteric drainage in simultaneous pancreas-kidney transplantation.

PubMed

Kave, Ben; Yii, Ming; Bell, Roger; Kanellis, John; Scott, David; Saunder, Alan

2010-10-01

Pancreas-kidney transplantation is currently the most effective method to re-establish euglycaemia in insulin-dependent diabetics with associated renal failure. The standard technique employed has been bladder drainage of exocrine secretions coupled with systemic venous drainage ('systemic-bladder' (SB) drainage). The more physiological technique, enteric exocrine with portal venous drainage ('portal-enteric' (PE) drainage), has been utilized sparingly in the past as a result of fears of technical complications. This paper compares the Monash Medical Centre experience with both techniques. A total of 68 simultaneous pancreas-kidney transplantations were performed at Monash Medical Centre from 1991 until 2004. The first 37 received SB drainage. Since March 2001, 27 have received PE drainage. This retrospective study compared the SB group (n= 37) with the PE group (n= 27), with a 2-year follow-up, examining a number of surgical outcomes. Two-year patient (94.3 versus 96.0%), kidney (89.2 versus 85.2%), pancreas (77.9 versus 71.4%) and event-free (73.0 versus 67.7%) survivals were all similar between the SB and PE groups, respectively. Although surgery took longer in PE subjects (4 h : 47 min ± 0:48 versus 5 h : 16 min ± 1:00; P= 0.045), less intraoperative transfusions were required (1.3 ± 1.43 versus 0.52 ± 0.90; P= 0.024). Length of hospital stay and time to insulin independence were similar. Pancreas graft thrombosis rates were similar (10.8% SB versus 7.4% PE, P= 0.497). PE drainage is a safe and viable method for pancreas transplantation, which can be performed with excellent outcomes. An increased rate of complications with PE drainage has not been demonstrated in this series. © 2009 The Authors. ANZ Journal of Surgery © 2009 Royal Australasian College of Surgeons.

Properties of the subglacial till inferred from supraglacial lake drainage

NASA Astrophysics Data System (ADS)

Neufeld, J. A.; Hewitt, D.

2017-12-01

The buildup and drainage of supraglacial lakes along the margins of the Greenland ice sheet has been previously observed using detailed GPS campaigns which show that rapid drainage events are often preceded by localised, transient uplift followed by rapid, and much broader scale, uplift and flexure associated with the main drainage event [1,2]. Previous models of these events have focused on fracturing during rapid lake drainage from an impermeable bedrock [3] or a thin subglacial film [4]. We present a new model of supraglacial drainage that couples the water flux from rapid lake drainage events to a simplified model of the pore-pressure in a porous, subglacial till along with a simplified model of the flexure of glacial ice. Using a hybrid mathematical model we explore the internal transitions between turbulent and laminar flow throughout the evolving subglacial cavity and porous till. The model predicts that an initially small water flux may locally increase pore-pressure in the till leading to uplift and a local divergence in the ice velocity that may ultimately be responsible for large hydro-fracturing and full-scale drainage events. Furthermore, we find that during rapid drainage while the presence of a porous, subglacial till is crucial for propagation, the manner of spreading is remarkably insensitive to the properties of the subglacial till. This is in stark contrast to the post-drainage relaxation of the pore pressure, and hence sliding velocity, which is highly sensitive to the permeability, compressibility and thickness of subglacial till. We use our model, and the inferred sensitivity to the properties of the subglacial till after the main drainage event, to infer the properties of the subglacial till. The results suggest that a detailed interpretation of supraglacial lake drainage may provide important insights into the hydrology of the subglacial till along the margins of the Greenland ice sheet, and the coupling of pore pressure in subglacial till with the observed ice velocity. 1 Das et al. Science 320, 778-781 (2008) 2 Stevens et al. Nature 522, 73-76 (2015) 3 Tsai & Rice J. Geophys. Res. 115, 1-18 (2010) 4 Adhikari & Tsai J. Geophys. Res. 120, 580-603 (2015)

Double layer drainage performance of porous asphalt pavement

NASA Astrophysics Data System (ADS)

Ji, Yangyang; Xie, Jianguang; Liu, Mingxi

2018-06-01

In order to improve the design reliability of the double layer porous asphalt pavement, the 3D seepage finite element method was used to study the drainage capacity of double layer PAC pavements with different geometric parameters. It revealed that the effect of pavement drainage length, slope, permeability coefficient and structure design on the drainage capacity. The research of this paper can provide reference for the design of double layer porous asphalt pavement in different rainfall intensity areas, and provide guides for the related engineering design.

Traumatic pancreatic pseudocysts.

PubMed

Popoola, D; Lou, M A; Sims, E H

1983-05-01

At the Martin Luther King, Jr, General Hospital in Los Angeles, during the period from June 1972 to April 1981, seven patients underwent surgery for traumatic pancreatic pseudocysts. The overall average age was 28 and the average hospital stay was 31 days. Ultrasound was the most useful test for diagnosis and follow-up. Preoperatively, serum amylases were not consistently elevated. Overall recurrences and complications totaled 57 percent. There were no deaths. The authors consider a large cystogastrostomy the treatment of choice for mature cysts that are satisfactorily adherent to the stomach. The second preference is a Roux-en-Y cystojejunostomy. External drainage was employed for acute cysts that required drainage. A distal pancreatectomy was performed for patients with small pancreatic tail pseudocysts. Patients who underwent acute drainage were usually drained externally and had a poorer outcome than patients who were operated on later with internal drainage. When compared with another group of 15 alcoholic patients who were operated on for pancreatic pseudocysts, patients with traumatic pseudocysts had a poorer outcome.

Update of the Accounting Surface Along the Lower Colorado River

USGS Publications Warehouse

Wiele, Stephen M.; Leake, Stanley A.; Owen-Joyce, Sandra J.; McGuire, Emmet H.

2008-01-01

The accounting-surface method was developed in the 1990s by the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, to identify wells outside the flood plain of the lower Colorado River that yield water that will be replaced by water from the river. This method was needed to identify which wells require an entitlement for diversion of water from the Colorado River and need to be included in accounting for consumptive use of Colorado River water as outlined in the Consolidated Decree of the United States Supreme Court in Arizona v. California. The method is based on the concept of a river aquifer and an accounting surface within the river aquifer. The study area includes the valley adjacent to the lower Colorado River and parts of some adjacent valleys in Arizona, California, Nevada, and Utah and extends from the east end of Lake Mead south to the southerly international boundary with Mexico. Contours for the original accounting surface were hand drawn based on the shape of the aquifer, water-surface elevations in the Colorado River and drainage ditches, and hydrologic judgment. This report documents an update of the original accounting surface based on updated water-surface elevations in the Colorado River and drainage ditches and the use of simple, physically based ground-water flow models to calculate the accounting surface in four areas adjacent to the free-flowing river.

Geographic Information Systems Methods for Determining Drainage-Basin Areas, Stream-Buffered Areas, Stream Length, and Land Uses for the Neosho and Spring Rivers in Northeastern Oklahoma

USGS Publications Warehouse

Masoner, Jason R.; March, Ferrella

2006-01-01

Geographic Information Systems have many uses, one of which includes the reproducible computation of environmental characteristics that can be used to categorize hydrologic features. The Oklahoma Department of Wildlife Conservation and the Oklahoma Department of Environmental Quality are investigating Geographic Information Systems techniques to determine partial drainage-basin areas, stream-buffer areas, stream length, and land uses (drainage basin and stream characteristics) in northeastern Oklahoma. The U.S Geological Survey, in cooperation with Oklahoma Department of Wildlife Conservation and the Oklahoma Department of Environmental Quality, documented the methods used to determine drainage-basin and stream characteristics for the Neosho and Spring Rivers above Grand Lake Of the Cherokees in northeastern Oklahoma and calculated the characteristics. The drainage basin and stream characteristics can be used by the Oklahoma Department of Wildlife Conservation and the Oklahoma Department of Environmental Quality to aid in natural-resource assessments.

Impact of Drainage Networks on Cholera Outbreaks in Lusaka, Zambia

PubMed Central

Suzuki, Hiroshi; Fujino, Yasuyuki; Kimura, Yoshinari; Cheelo, Meetwell

2009-01-01

Objectives. We investigated the association between precipitation patterns and cholera outbreaks and the preventative roles of drainage networks against outbreaks in Lusaka, Zambia. Methods. We collected data on 6542 registered cholera patients in the 2003–2004 outbreak season and on 6045 cholera patients in the 2005–2006 season. Correlations between monthly cholera incidences and amount of precipitation were examined. The distribution pattern of the disease was analyzed by a kriging spatial analysis method. We analyzed cholera case distribution and spatiotemporal cluster by using 2590 cholera cases traced with a global positioning system in the 2005–2006 season. The association between drainage networks and cholera cases was analyzed with regression analysis. Results. Increased precipitation was associated with the occurrence of cholera outbreaks, and insufficient drainage networks were statistically associated with cholera incidences. Conclusions. Insufficient coverage of drainage networks elevated the risk of cholera outbreaks. Integrated development is required to upgrade high-risk areas with sufficient infrastructure for a long-term cholera prevention strategy. PMID:19762668

Evaluation of airborne thermal infrared imagery for locating mine drainage sites in the Lower Youghiogheny River Basin, Pennsylvania, USA

USGS Publications Warehouse

Sams, James I.; Veloski, Garret; Ackman, T.E.

2003-01-01

Nighttime high-resolution airborne thermal infrared imagery (TIR) data were collected in the predawn hours during Feb 5-8 and March 11-12, 1999, from a helicopter platform for 72.4 km of the Youghiogheny River, from Connellsville to McKeesport, in southwestern Pennsylvania. The TIR data were used to identify sources of mine drainage from abandoned mines that discharge directly into the Youghiogheny River. Image-processing and geographic information systems (GIS) techniques were used to identify 70 sites within the study area as possible mine drainage sources. The combination of GIS datasets and the airborne TIR data provided a fast and accurate method to target the possible sources. After field reconnaissance, it was determined that 24 of the 70 sites were mine drainage. This paper summarizes: the procedures used to process the TIR data and extract potential mine-drainage sites; methods used for verification of the TIR data; a discussion of factors affecting the TIR data; and a brief summary of water quality.

Surfactant-induced flow compromises determination of air-water interfacial areas by surfactant miscible-displacement.

PubMed

Costanza-Robinson, Molly S; Henry, Eric J

2017-03-01

Surfactant miscible-displacement (SMD) column experiments are used to measure air-water interfacial area (A I ) in unsaturated porous media, a property that influences solute transport and phase-partitioning. The conventional SMD experiment results in surface tension gradients that can cause water redistribution and/or net drainage of water from the system ("surfactant-induced flow"), violating theoretical foundations of the method. Nevertheless, the SMD technique is still used, and some suggest that experimental observations of surfactant-induced flow represent an artifact of improper control of boundary conditions. In this work, we used numerical modeling, for which boundary conditions can be perfectly controlled, to evaluate this suggestion. We also examined the magnitude of surfactant-induced flow and its impact on A I measurement during multiple SMD flow scenarios. Simulations of the conventional SMD experiment showed substantial surfactant-induced flow and consequent drainage of water from the column (e.g., from 75% to 55% S W ) and increases in actual A I of up to 43%. Neither horizontal column orientation nor alternative boundary conditions resolved surfactant-induced flow issues. Even for simulated flow scenarios that avoided surfactant-induced drainage of the column, substantial surfactant-induced internal water redistribution occurred and was sufficient to alter surfactant transport, resulting in up to 23% overestimation of A I . Depending on the specific simulated flow scenario and data analysis assumptions used, estimated A I varied by nearly 40% and deviated up to 36% from the system's initial A I . We recommend methods for A I determination that avoid generation of surface-tension gradients and urge caution when relying on absolute A I values measured via SMD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling of wind gap formation and development of sedimentary basins during fold growth: application to the Zagros Fold Belt, Iran.

NASA Astrophysics Data System (ADS)

Collignon, Marine; Yamato, Philippe; Castelltort, Sébastien; Kaus, Boris

2016-04-01

Mountain building and landscape evolution are controlled by the interactions between river dynamics and tectonic forces. Such interactions have been largely studied but a quantitative evaluation of tectonic/geomorphic feedbacks remains required for understanding sediments routing within orogens and fold-and-thrust belts. Here, we employ numerical simulations to assess the conditions of uplift and river incision necessary to deflect an antecedent drainage network during the growth of one or several folds. We propose that a partitioning of the river network into internal (endorheic) and longitudinal drainage arises as a result of lithological differences within the deforming crustal sedimentary cover. We show with examples from the Zagros Fold Belt (ZFB) that drainage patterns can be linked to the incision ratio R between successive lithological layers, corresponding to the ratio between their relative erodibilities or incision coefficients. Transverse drainage networks develop for uplift rates smaller than 0.8 mm.yr-1 and -10 < R < 10. Intermediate drainage network are obtained for uplift rates up to 2 mm.yr-1 and incision ratios of 20. Parallel drainage networks and formation of sedimentary basins occur for large values of incision ratio (R >20) and uplift rates between 1 and 2 mm.yr-1. These results have implications for predicting the distribution of sediment depocenters in fold-and-thrust belts, which can be of direct economic interest for hydrocarbon exploration.

The usefulness of adding p53 immunocytochemistry to bile drainage cytology for the diagnosis of malignant biliary strictures.

PubMed

Yeo, Min-Kyung; Kim, Kyung-Hee; Lee, Yong-Moon; Lee, Byung Seok; Choi, Song-Yi

2017-07-01

Obstructive jaundice is frequently caused by bile duct strictures. Determination of malignant strictures is crucial for the initiation of appropriate treatment. Cytologic examination of bile drainage fluid is an easy and reproducible method of detecting malignant cells. This method, however, frequently yields indeterminate results, such as atypia or suspicious of malignancy, due to difficulties in differentiating malignancy from benign atypia. Immunocytochemical assessment of p53 expression by cells in bile drainage fluid may enhance the ability to detect malignancy. A total of 139 samples of bile drainage fluid were obtained from 80 patients. Following cytologic examination, the samples were incubated with antibody to p53. The performance of cytology with and without p53 immunocytochemistry was evaluated, with reference to surgical or clinical findings of benign and malignant biliary strictures. Bile drainage cytology alone had a sensitivity of 31.6% and a specificity of 98.4% in the identification of malignant strictures, whereas the combination of p53 immunocytochemistry and bile drainage cytology had a sensitivity of 80.3% and a specificity of 92.1%. P53 immunocytochemistry alone had a sensitivity of 64.5% and a specificity of 92.7% for the identification of malignant strictures in bile drainage samples with atypical cytology, and a sensitivity of 85.0% and a specificity of 100.0% in samples with suspicious of malignancy. The addition of p53 immunocytochemistry to bile drainage cytology can be useful in identifying malignant strictures in samples showing indeterminate results on bile drainage cytology. Diagn. Cytopathol. 2017;45:592-597. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effect of Physical Methods of Lymphatic Drainage on Postexercise Recovery of Mixed Martial Arts Athletes.

PubMed

Zebrowska, Aleksandra; Trybulski, Robert; Roczniok, Robert; Marcol, Wieslaw

2017-08-16

Physical methods are reported to be important for accelerating skeletal muscle regeneration, decreasing muscle soreness, and shortening of the recovery time. The aim of the study was to assess the effect of the physical methods of lymphatic drainage (PMLD) such as manual lymphatic drainage (MLD), the Bodyflow (BF) therapy, and lymphatic drainage by deep oscillation (DO) on postexercise regeneration of the forearm muscles of mixed martial arts (MMA) athletes. Eighty MMA athletes aged 27.5 ± 6.4 years were allocated to 4 groups: MLD, the BF device, DO therapy, and the control group. Blood flow velocity in the cephalic vein was measured with the ultrasound Doppler velocity meter. Maximal strength of the forearm muscles (Fmax), muscle tissue tension, pain threshold, blood lactate concentration (LA), and activity of creatine kinase were measured in all groups at rest, after the muscle fatigue test (post-ex) and then 20 minutes, 24, and 48 hours after the application of PMLD. The muscle fatigue test reduced Fmax in all subjects, but in the groups receiving MLD, DO, and BF significantly higher Fmax was observed at recovery compared with post-ex values. The application of MDL reduced the postexercise blood LA and postexercise muscle tension. The lymphatic drainage methods, whether manual or using electro-stimulation and DO, improve postexercise regeneration of the forearm muscles of MMA athletes. The methods can be an important element of therapeutic management focused on optimizing training effects and reducing the risk of injuries of the combat sports athletes.

Malignant Ureteral Obstruction: Functional Duration of Metallic versus Polymeric Ureteral Stents

PubMed Central

Chow, Po-Ming; Chiang, I-Ni; Chen, Chia-Yen; Huang, Kuo-How; Hsu, Jui-Shan; Wang, Shuo-Meng; Lee, Yuan-Ju; Yu, Hong-Jeng; Pu, Yeong-Shiau; Huang, Chao-Yuan

2015-01-01

Background Ureteral obstruction caused by extrinsic compression is often associated with intra-abdominal cancers. Internal drainage with ureteral stents is typically the first-line therapy to relieve such obstructions. Novel designs of ureteral stents made of different materials have been invented to achieve better drainage. In this study, we described the functional outcomes of a Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) in patients with malignant ureteral obstruction and compare the functional duration of Resonance stents with regular polymeric stents in the same cohort. Methods Cancer patients who received polymeric stents and subsequent Resonance stents for ureteral obstruction between July 2009 and November 2012 were included in a chart review. Stent failure was detected by clinical symptoms, imaging studies, and renal function tests. The functional durations of each stent were calculated, and possible factors affecting stent patency were investigated. Results A total of 50 stents were successfully inserted into 50 ureteral units in 42 patients with malignant ureteral obstruction. There were 7 antegrade stents and 43 retrograde stents. There were no major complications. Stent-related symptoms were similar in both kinds of stents. After polymeric stents were replaced with Resonance metallic stents, hydronephrosis subsided or remained stable in 90% (45/50) of the ureteral units. Serum creatinine decreased or remained stable in 90% (38/42) of these patients. The Resonance stent exhibited a mean increase in functional duration of 4 months compared with the polymeric stents (p<0.0001), and 50% (25/50) of the Resonance stents exhibited a significant increase in functional duration (more than 3 months). Pre-operative serum creatinine < 2 was associated with a substantial increase in stent duration. Conclusions Resonance stents are effective and safe in relieving malignant ureteral obstructions after polymeric stents failure. Resonance stents can provide a longer functional duration than polymeric stents and should be offered as an option for internal drainage. PMID:26267140

Percutaneous drainage of Morel-Lavallée lesions when the diagnosis is delayed.

PubMed

Zhong, Biao; Zhang, Chi; Luo, Cong-feng

2014-10-01

Morel-Lavallée lesions are a closed internal degloving, and open débridement can damage the only remaining blood supply to the skin. We performed percutaneous draining and débridement to treat 8 patients in whom the diagnosis of Morel-Lavallée lesions was delayed more than 1 week. Here we discuss our treatment procedures and the outcomes in these 8 patients. We consider percutaneous drainage to be an effective treatment for patients with delayed diagnosis of Morel-Lavallée lesions.

Assessment of Characteristics and Remedial Alternatives for Abandoned Mine Drainage: Case Study at Staple Bend Tunnel Unit of Allegheny Portage Railroad National Historic Site, Cambria County, Pennsylvania, 2004

DTIC Science & Technology

2005-01-01

water quality-Northern Appalachian Basin, In Brady, K. B. C., Smith, M. W., and Schueck, J. H., (eds.), Coal Mine Drainage Prediction and Pollution ...United States: Water , Air, and Soil Pollution , v. 50, p. 91-107. Hyman, D. M., and Watzlaf, G. R., 1997, Metals and other components of coal mine...Advances in the hydrochemistry and microbiology of acid mine waters : International Geology Review, v. 42, p. 499-515. Nordstrom, D. K., and Alpers, C

Randomized, controlled pilot study comparing large-volume paracentesis using wall suction and traditional glass vacuum bottle methods.

PubMed

Konerman, Monica A; Price, Jennifer; Torres, Dawn; Li, Zhiping

2014-09-01

Large-volume paracentesis (LVP) can be time and labor intensive depending on the amount of ascites removed and the method of drainage. Wall suction has been adopted as the preferred method of drainage at many centers, though the safety and benefits of this technique have not been formally evaluated. The primary objective of this study was to define the cost and time savings of wall suction over the traditional glass vacuum bottle method for ascites drainage. The secondary objective was to compare the safety profile and patient satisfaction using these two techniques. We conducted a randomized, controlled pilot study of the wall suction versus vacuum bottle methods for LVP in hospitalized patients. All LVPs were performed under ultrasound guidance by a single proceduralist. Patients with at least 4 liters removed received 25% intravenous albumin, 8 g/liter fluid removed. Demographic, clinical characteristics, and procedure details were recorded. Laboratory and hemodynamic data were recorded for 24 h prior to and 24-48 h post LVP. An electronic chart review was conducted to evaluate procedure-related complications. Data were compared using Fisher's exact test, t test, or Mann-Whitney U test. Thirty-four patients were randomized to wall suction at 200 mmHg (n = 17) or glass vacuum bottle drainage (n = 17). Wall suction was significantly faster and less costly than vacuum bottle drainage (7 versus 15 min, p = 0.002; $4.59 versus $12.73, p < 0.001). There were no differences in outcomes at 24 and 48 h post LVP, or at 60-day follow up. Performing LVP using wall suction resulted in significantly shorter procedure time and supply cost savings. There were no differences in outcomes between the groups, suggesting equivalent safety, though larger studies powered to detect small differences are needed. Given its efficiency, convenience, and cost effectiveness, wall suction may be a superior method of ascites drainage for LVP.

Quantifying the Cerebral Hemodynamics of Dural Arteriovenous Fistula in Transverse Sigmoid Sinus Complicated by Sinus Stenosis: A Retrospective Cohort Study.

PubMed

Guo, W-Y; Lee, C-C J; Lin, C-J; Yang, H-C; Wu, H-M; Wu, C-C; Chung, W-Y; Liu, K-D

2017-01-01

Sinus stenosis occasionally occurs in dural arteriovenous fistulas. Sinus stenosis impedes venous outflow and aggravates intracranial hypertension by reversing cortical venous drainage. This study aimed to analyze the likelihood of sinus stenosis and its impact on cerebral hemodynamics of various types of dural arteriovenous fistulas. Forty-three cases of dural arteriovenous fistula in the transverse-sigmoid sinus were reviewed and divided into 3 groups: Cognard type I, type IIa, and types with cortical venous drainage. Sinus stenosis and the double peak sign (occurrence of 2 peaks in the time-density curve of the ipsilateral drainage of the internal jugular vein) in dural arteriovenous fistula were evaluated. "TTP" was defined as the time at which a selected angiographic point reached maximum concentration. TTP of the vein of Labbé, TTP of the ipsilateral normal transverse sinus, trans-fistula time, and trans-stenotic time were compared across the 3 groups. Thirty-six percent of type I, 100% of type IIa, and 84% of types with cortical venous drainage had sinus stenosis. All sinus stenosis cases demonstrated loss of the double peak sign that occurs in dural arteriovenous fistula. Trans-fistula time (2.09 seconds) and trans-stenotic time (0.67 seconds) in types with cortical venous drainage were the most prolonged, followed by those in type IIa and type I. TTP of the vein of Labbé was significantly shorter in types with cortical venous drainage. Six patients with types with cortical venous drainage underwent venoplasty and stent placement, and 4 were downgraded to type IIa. Sinus stenosis indicated dysfunction of venous drainage and is more often encountered in dural arteriovenous fistula with more aggressive types. Venoplasty ameliorates cortical venous drainage in dural arteriovenous fistulas and serves as a bridge treatment to stereotactic radiosurgery in most cases. © 2017 by American Journal of Neuroradiology.

How to secure the connection between thoracostomy tube and drainage system?

PubMed

Li, Ka Ki Pat; Wong, Kit Shing John; Wong, Yau Hang Henry; Cheng, Ka Lok; So, Fung Ling; Lau, Chu Leung; Kam, Chak Wah

2014-01-01

Thoracostomy tube insertion is one of the common bedside procedures in emergency medicine and many acute specialties. Dislodgement of thoracostomy tube from the connection tube of chest drainage system is an important problem with potential complications such as contamination, infection and pneumothorax. Besides, mere loosening can also lead to malfunction. It is a common practice to tape the connection of the system. This study aimed to evaluate the materials and methods of connection of chest drain system to minimize drainage dislodgement. We conducted an experimental study to assess the tightness of the connection with various taping materials and methods. We selected three commonly used adhesive materials (3M™ Transpore™ Medical tape, 3M™ Micropore™ Medical tape, 3M™ Soft Cloth Tape on Liner) and three different methods (cross method, straight method, nylon band) to secure the junction between the thoracostomy tube and the bi-conical adaptor in the drainage system. The measured outcome was the weight causing visible loosening of the junction between thoracotomy tube and the adaptor. For each taping material and taping method, 10 trials were performed. The median weight required to disconnect the junction is 26.22 lb for Transpore™, 31.29 lb for Micropore™ and 32.44 lb for Soft Cloth Tape on Liner. A smaller force was required to disconnect if Transpore™ is used (P<0.001). There was no statistical significant difference between Micropore™ and Soft Cloth Tape on Liner (P=0.98). The median disconnecting force is 32.44 lb for straight taping method, 40.55 lb for cross taping method and 21.15 lb for plastic band. The cross-taping method was the more secure method (P<0.0001 when compared with plastic band) (P=0.033 when compared with straight method). Cross-taping is the most secure method among the tested varieties in connecting the thoracostomy tube to the chest drainage system. Transpore™ is not a recommended material for thoracostomy tube taping.

A portable thoracic closed drainage instrument for hemopneumothorax.

PubMed

Tang, Hua; Pan, Tiewen; Qin, Xiong; Xue, Lei; Wu, Bin; Zhao, Xuewei; Sun, Guangyuan; Yuan, Xinyu; Xu, Zhifei

2012-03-01

Hemopneumothorax is a common sequelae of traumatic thoracic injury. The most effective treatment of this condition is thoracic drainage. Despite the common occurrence of this condition, available instruments are difficult to use emergently, particularly when large amounts of patients need to be drained. In the present experiment, a newly designed chest tube and thoracic closed drainage package is described and preliminarily evaluated with the goal to improve the treatment of traumatic hemopneumothorax. Twenty canines were divided into two groups. In one group, the newly designed thoracic closed drainage package was used, whereas in the other group a currently available chest tube and bottle were used. Drainage test, ultrasound examination, flushing test, and tension test were performed to evaluate the effectiveness of the drainage package. We found that the newly-designed drainage tube is as effective as the common tube when evaluated using all of the chosen methods. In addition, the package is very lightweight and portable. The newly-designed thoracic drainage package is very effective in the emergency treatment of thoracic trauma and may be more suitable for the emergency treatment of hemopneumothorax.

Can Nocturnal Cold Air Drainage be Used to Monitor Ecosystem Function?

NASA Astrophysics Data System (ADS)

Pypker, T. G.; Unsworth, M. H.; Sulzman, E. W.; Lamb, B.; Allwine, G.; Mix, A. C.; Bond, B. J.

2005-12-01

Ecosystem carbon dynamics in flat, uniform terrain are commonly studied using standard micrometeorological techniques such as eddy covariance or gradient methods. But many of the world's ecosystems are in complex topography that is inappropriate for these methods. Nocturnal cold air drainage commonly occurs in mountainous terrain. This drainage provides an opportunity to monitor ecosystem carbon dynamics because as air flows downhill through a watershed, it collects respired CO2 from the soil and vegetation. If the nocturnal drainage can be treated as a river of air flowing down a valley, sampling this air from a tower at the base of a watershed could provide an estimate of ecosystem respiration and the 12C/13C ratio. To interpret the measured CO2 and the 12C/13C ratio, the characteristics of the drainage and the footprint (source area) of air passing the tower must be understood. To explore the potential of using nocturnal cold air drainage we built a 37 m tower at the base of a deeply incised watershed of ~40 y-old Douglas-fir in the Oregon Cascades. At various heights on the tower we monitored air temperature, wind speed/direction, and the CO2 concentration and 12C/13C isotopic ratio with a combination of thermistors, sonic anemometers (2-D and 3-D) and a CO2 profile system. The temperature gradient along the axis of the watershed was monitored by 30 temperature sensors from the base to the top of the watershed. The maximum drainage windspeeds on the tower occurred near sunset and, unlike past reports of cold air drainage, this drainage was very deep (> 37 m). The drainage became well mixed when the vertical profile of potential temperature became isothermal. It remained well mixed through the night into the early morning. The drainage occurred on most summer nights and typically provided a range of CO2 (> 60 ppm) sufficient for "Keeling plot" analysis. In September 2005, we released a tracer in the watershed (SF6) to determine the varying footprint size of the tower. The footprint size and windspeed varied throughout the night, resulting in a change in the CO2 concentration at the tower. Further analysis will determine how the CO2 passing the tower is altered by entrainment of the air overlying the drainage and the change in the source area of the drainage.

The usefulness of Wi-Fi based digital chest drainage system in the post-operative care of pneumothorax

PubMed Central

Cho, Hyun Min; Hong, Yoon Joo; Byun, Chun Sung

2016-01-01

Background Chest drainage systems are usually composed of chest tube and underwater-seal bottle. But this conventional system may restrict patients doing exercise and give clinicians obscure data about when to remove tubes because there is no objective indicator. Recently developed digital chest drainage systems may facilitate interpretation of the grade of air leak and make it easy for clinicians to decide when to remove chest tubes. In addition, with combination of wireless internet devices, monitoring and managing of drainage system distant from the patient is possible. Methods Sixty patients of primary pneumothorax were included in a prospective randomized study and divided into two groups. Group I (study) consisted of digital chest drainage system while in group II (control), conventional underwater-seal chest bottle system was used. Data was collected from January, 2012 to September, 2013 in Eulji University Hospital, Daejeon, Korea. Results There was no difference in age, sex, smoking history and postoperative pain between two groups. But the average length of drainage was 2.2 days in group I and 3.1 days in group II (P<0.006). And more, about 90% of the patients in group I was satisfied with using new device for convenience. Conclusions Digital system was beneficial on reducing the length of tube drainage by real time monitoring. It also had advantage in portability, loudness and gave more satisfaction than conventional system. Moreover, internet based digital drainage system will be a good method in thoracic telemedicine area in the near future. PMID:27076934

Statewide analysis of the drainage-area ratio method for 34 streamflow percentile ranges in Texas

USGS Publications Warehouse

Asquith, William H.; Roussel, Meghan C.; Vrabel, Joseph

2006-01-01

The drainage-area ratio method commonly is used to estimate streamflow for sites where no streamflow data are available using data from one or more nearby streamflow-gaging stations. The method is intuitive and straightforward to implement and is in widespread use by analysts and managers of surface-water resources. The method equates the ratio of streamflow at two stream locations to the ratio of the respective drainage areas. In practice, unity often is assumed as the exponent on the drainage-area ratio, and unity also is assumed as a multiplicative bias correction. These two assumptions are evaluated in this investigation through statewide analysis of daily mean streamflow in Texas. The investigation was made by the U.S. Geological Survey in cooperation with the Texas Commission on Environmental Quality. More than 7.8 million values of daily mean streamflow for 712 U.S. Geological Survey streamflow-gaging stations in Texas were analyzed. To account for the influence of streamflow probability on the drainage-area ratio method, 34 percentile ranges were considered. The 34 ranges are the 4 quartiles (0-25, 25-50, 50-75, and 75-100 percent), the 5 intervals of the lower tail of the streamflow distribution (0-1, 1-2, 2-3, 3-4, and 4-5 percent), the 20 quintiles of the 4 quartiles (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45, 45-50, 50-55, 55-60, 60-65, 65-70, 70-75, 75-80, 80-85, 85-90, 90-95, and 95-100 percent), and the 5 intervals of the upper tail of the streamflow distribution (95-96, 96-97, 97-98, 98-99 and 99-100 percent). For each of the 253,116 (712X711/2) unique pairings of stations and for each of the 34 percentile ranges, the concurrent daily mean streamflow values available for the two stations provided for station-pair application of the drainage-area ratio method. For each station pair, specific statistical summarization (median, mean, and standard deviation) of both the exponent and bias-correction components of the drainage-area ratio method were computed. Statewide statistics (median, mean, and standard deviation) of the station-pair specific statistics subsequently were computed and are tabulated herein. A separate analysis considered conditioning station pairs to those stations within 100 miles of each other and with the absolute value of the logarithm (base-10) of the ratio of the drainage areas greater than or equal to 0.25. Statewide statistics of the conditional station-pair specific statistics were computed and are tabulated. The conditional analysis is preferable because of the anticipation that small separation distances reflect similar hydrologic conditions and the observation of large variation in exponent estimates for similar-sized drainage areas. The conditional analysis determined that the exponent is about 0.89 for streamflow percentiles from 0 to about 50 percent, is about 0.92 for percentiles from about 50 to about 65 percent, and is about 0.93 for percentiles from about 65 to about 85 percent. The exponent decreases rapidly to about 0.70 for percentiles nearing 100 percent. The computation of the bias-correction factor is sensitive to the range analysis interval (range of streamflow percentile); however, evidence suggests that in practice the drainage-area method can be considered unbiased. Finally, for general application, suggested values of the exponent are tabulated for 54 percentiles of daily mean streamflow in Texas; when these values are used, the bias correction is unity.

Ultrasound assessment of lung consolidation and reaeration after pleural effusion drainage in patients with Acute Respiratory Distress Syndrome: a pilot study.

PubMed

Chinardet, B; Brisson, H; Arbelot, C; Langeron, O; Rouby, J J; Lu, Q

2016-01-01

The aim of the pilot study was to assess by ultrasound changes in dimensions of lung consolidation and reaeration after drainage of large pleural effusion in patients with acute respiratory distress syndrome (ARDS). Lung ultrasound and blood gas were performed before, 2 hours (H2) and 24 hours (H24) after drainage of pleural effusion. Lung ultrasound aeration score was calculated. Cephalocaudal dimension and diaphragmatic transversal area of lung consolidation were measured. Ten patients were studied. Median volume of drained effusion was 675 ml at H2 and 895 at H24. Two hours after drainage, dimension of cephalocaudal consolidation and diaphragmatic transversal area decreased significantly. Lung reaeration after drainage occurred mainly in latero-inferior and postero-superior regions. PaO2/FiO2 increased significantly at H24. Ultrasound is a useful method to assess lung consolidation after pleural effusion drainage. Drainage of pleural effusion may lead to a decrease of lung consolidation and improvement of lung reaeration.

EUS-guided drainage is more successful in pancreatic pseudocysts compared with abscesses

PubMed Central

Sadik, Riadh; Kalaitzakis, Evangelos; Thune, Anders; Hansen, Jan; Jönson, Claes

2011-01-01

AIM: To compare the results for endoscopic ultrasound (EUS)-guided drainage of clear fluid pancreatic pseudocysts with the results for abscess drainage. METHODS: All patients referred for endoscopic drainage of a fluid collection were prospectively included. The outcome was recorded. RESULTS: Altogether 26 pseudocysts or abscesses were treated in 25 (6 female) patients. One endoscopist performed the procedures. Non-infected pseudocysts were present in 15 patients and 10 patients had infected fluid collections. The cyst size ranged between 28 cm × 13 cm and 5 cm × 5 cm. The EUS drainage was successful in 94% of the pseudocysts and in 80% of the abscesses (P = 0.04). The complication rate in pseudocysts was 6% and in abscesses was 30% (P = 0.02). Recurrence of a pseudocyst occurred in one patient (4%) after 6 mo; the patient was successfully retreated. CONCLUSION: EUS-guided drainage of pseudocysts is associated with a higher success rate and a lower complication rate compared with abscess drainage. PMID:21274380

Probabilistic modelling of overflow, surcharge and flooding in urban drainage using the first-order reliability method and parameterization of local rain series.

PubMed

Thorndahl, S; Willems, P

2008-01-01

Failure of urban drainage systems may occur due to surcharge or flooding at specific manholes in the system, or due to overflows from combined sewer systems to receiving waters. To quantify the probability or return period of failure, standard approaches make use of the simulation of design storms or long historical rainfall series in a hydrodynamic model of the urban drainage system. In this paper, an alternative probabilistic method is investigated: the first-order reliability method (FORM). To apply this method, a long rainfall time series was divided in rainstorms (rain events), and each rainstorm conceptualized to a synthetic rainfall hyetograph by a Gaussian shape with the parameters rainstorm depth, duration and peak intensity. Probability distributions were calibrated for these three parameters and used on the basis of the failure probability estimation, together with a hydrodynamic simulation model to determine the failure conditions for each set of parameters. The method takes into account the uncertainties involved in the rainstorm parameterization. Comparison is made between the failure probability results of the FORM method, the standard method using long-term simulations and alternative methods based on random sampling (Monte Carlo direct sampling and importance sampling). It is concluded that without crucial influence on the modelling accuracy, the FORM is very applicable as an alternative to traditional long-term simulations of urban drainage systems.

Monitoring earthen dams and levees with ambient seismic noise

NASA Astrophysics Data System (ADS)

Planès, T.; Mooney, M.; Rittgers, J. B.; Kanning, W.; Draganov, D.

2017-12-01

Internal erosion is a major cause of failure of earthen dams and levees and is difficult to detect at an early stage by traditional visual inspection techniques. The passive and non-invasive ambient-noise correlation technique could help detect and locate internal changes taking place within these structures. First, we apply this passive seismic method to monitor a canal embankment model submitted to piping erosion, in laboratory-controlled conditions. We then present the monitoring of a sea levee in the Netherlands. A 150m-long section of the dike shows sandboils in the drainage ditch located downstream of the levee. These sandboils are the sign of concentrated seepage and potential initiation of internal erosion in the structure. Using the ambient-noise correlation technique, we retrieve surface waves propagating along the crest of the dike. Temporal variations of the seismic wave velocity are then computed during the tide cycle. These velocity variations are correlated with local in-situ pore water pressure measurements and are possibly influenced by the presence of concentrated seepage paths.

Impacts of climate change on rainfall extremes and urban drainage systems: a review.

PubMed

Arnbjerg-Nielsen, K; Willems, P; Olsson, J; Beecham, S; Pathirana, A; Bülow Gregersen, I; Madsen, H; Nguyen, V-T-V

2013-01-01

A review is made of current methods for assessing future changes in urban rainfall extremes and their effects on urban drainage systems, due to anthropogenic-induced climate change. The review concludes that in spite of significant advances there are still many limitations in our understanding of how to describe precipitation patterns in a changing climate in order to design and operate urban drainage infrastructure. Climate change may well be the driver that ensures that changes in urban drainage paradigms are identified and suitable solutions implemented. Design and optimization of urban drainage infrastructure considering climate change impacts and co-optimizing these with other objectives will become ever more important to keep our cities habitable into the future.

[Management of septic arthritis].

PubMed

Debrach, Anne-Cécile; Lazarou, Ilias; Gabay, Cem; Uçkay, Ilker

2018-03-07

Native joint septic arthritis is a medical emergency requiring urgent joint drainage and antibiotic therapy. In the absence of an artificial joint or a foreign body, the « rheumatological approach » with repetitive arthrocentesis yields similar outcomes in the literature when compared to surgical drainage. Arthrocentesis could therefore be viewed as the preferential method of joint drainage as it is associated both with reduced morbidity for patients and decreased costs for the healthcare system. In case of failure with arthrocentesis, surgical arthroscopic drainage becomes necessary. In addition, the prescription of systemic steroids is promising but requires further studies, especially in adult patient populations.

Deciphering Fluvial-Capture-Induced Erosional Patterns at the Continental Scale on the Iberian Peninsula

NASA Astrophysics Data System (ADS)

Anton, L.; Munoz Martin, A.; De Vicente, G.; Finnegan, N. J.

2017-12-01

The process of river incision into bedrock dictates the landscape response to changes in climate and bedrock uplift in most unglaciated settings. Hence, understanding processes of river incision into bedrock and their topographic signatures are a basic goal of geomorphology. Formerly closed drainage basins provide an exceptional setting for the quantification of long term fluvial dissection and landscape change, making them valuable natural laboratories. Internally drained basins are peculiar because they trap all the sediment eroded within the watershed; as closed systems they do not respond to the base level of the global ocean and deposition is the dominant process. In that context, the opening of an outward drainage involves a sudden lowering of the base level, which is transmitted upstream along fluvial channels in the form of erosional waves, leading to high incision and denudation rates within the intrabasinal areas. Through digital topographic analysis and paleolandscape reconstruction based on relict deposits and landscapes on the Iberian Peninsula, we quantify the volume of sediments eroded from formerly internally drained basins since capture. Mapping of fluvial dissection patterns reveals how, and how far, regional waves of incision have propagated upstream. In our analysis, erosional patterns are consistent with the progressive establishment of an outward drainage system, providing a relative capture chronology for the different studied basins. Divide migration inferred from chi maps supports the interpretations based on fluvial dissection patterns and volumes, providing clues on how landscaped changed and how drainage integration occurred within the studied watersheds. [Funded by S2013/MAE-2739 and CGL2014-59516].

Digital database architecture and delineation methodology for deriving drainage basins, and a comparison of digitally and non-digitally derived numeric drainage areas

USGS Publications Warehouse

Dupree, Jean A.; Crowfoot, Richard M.

2012-01-01

The drainage basin is a fundamental hydrologic entity used for studies of surface-water resources and during planning of water-related projects. Numeric drainage areas published by the U.S. Geological Survey water science centers in Annual Water Data Reports and on the National Water Information Systems (NWIS) Web site are still primarily derived from hard-copy sources and by manual delineation of polygonal basin areas on paper topographic map sheets. To expedite numeric drainage area determinations, the Colorado Water Science Center developed a digital database structure and a delineation methodology based on the hydrologic unit boundaries in the National Watershed Boundary Dataset. This report describes the digital database architecture and delineation methodology and also presents the results of a comparison of the numeric drainage areas derived using this digital methodology with those derived using traditional, non-digital methods. (Please see report for full Abstract)

Annual peak discharges from small drainage areas in Montana through September 1976

USGS Publications Warehouse

Johnson, M.V.; Omang, R.J.; Hull, J.A.

1977-01-01

Annual peak discharge from small drainage areas is tabulated for 336 sites in Montana. The 1976 additions included data collected at 206 sites. The program which investigates the magnitude and frequency of floods from small drainage areas in Montana, was begun July 1, 1955. Originally 45 crest-stage gaging stations were established. The purpose of the program is to collect sufficient peak-flow data, which through analysis could provide methods for estimating the magnitude and frequency of floods at any point in Montana. The ultimate objective is to provide methods for estimating the 100-year flood with the reliability needed for road design. (Woodard-USGS)

Drainage pipe study.

DOT National Transportation Integrated Search

1971-05-01

This report is the result of a research program in which various types of submerged drainage structures were evaluated in an effort to determine the life expectancy of such a structure. California-s method of predicting the behavior pattern of submer...

Comparison of closed-chest drainage with rib resection closed drainage for treatment of chronic tuberculous empyema

PubMed Central

Fang, Yong; Xiao, Heping; Hu, Haili

2018-01-01

Background This study aimed to compare the efficacy of closed-chest drainage with rib resection closed drainage of chronic tuberculous empyema. Methods This retrospective study reviewed 86 patients with tuberculous empyema in Shanghai Pulmonary Hospital from August 2010 to November 2015. Among these included patients, 22 patients received closed-chest drainage, and 64 patients received rib resection closed drainage. Results The results showed that after intercostal chest closed drain treatment, 2 (9.09%) patients were recovery, 13 (59.09%) patients had significantly curative effect, 6 (27.27%) patients had partly curative effect, and 1 (4.55%) patient had negative effect. After treatment of rib resection closed drainage, 9 (14.06%) patients were successfully recovery, 31 (48.44%) patients had significantly curative effect, 19 (29.69%) patients had partly curative effect, and 5 (7.81%) patients had negative effect. There was no significant difference in the curative effect (P>0.05), while the average catheterization time of rib resection closed drainage (130.05±13.12 days) was significant longer than that (126.14±36.84 days) in course of intercostal chest closed drain (P<0.05). Conclusions This study had demonstrated that closed-chest drainage was an effective procedure for treating empyema in young patients. It was less invasive than rib resection closed drainage and was associated with less severe pain. We advocated closed-chest drainage for the majority of young patients with empyema, except for those with other diseases. PMID:29600066

Tokyo Guidelines 2018: management strategies for gallbladder drainage in patients with acute cholecystitis (with videos).

PubMed

Mori, Yasuhisa; Itoi, Takao; Baron, Todd H; Takada, Tadahiro; Strasberg, Steven M; Pitt, Henry A; Ukai, Tomohiko; Shikata, Satoru; Noguchi, Yoshinori; Teoh, Anthony Yuen Bun; Kim, Myung-Hwan; Asbun, Horacio J; Endo, Itaru; Yokoe, Masamichi; Miura, Fumihiko; Okamoto, Kohji; Suzuki, Kenji; Umezawa, Akiko; Iwashita, Yukio; Hibi, Taizo; Wakabayashi, Go; Han, Ho-Seong; Yoon, Yoo-Seok; Choi, In-Seok; Hwang, Tsann-Long; Chen, Miin-Fu; Garden, O James; Singh, Harjit; Liau, Kui-Hin; Huang, Wayne Shih-Wei; Gouma, Dirk J; Belli, Giulio; Dervenis, Christos; de Santibañes, Eduardo; Giménez, Mariano Eduardo; Windsor, John A; Lau, Wan Yee; Cherqui, Daniel; Jagannath, Palepu; Supe, Avinash Nivritti; Liu, Keng-Hao; Su, Cheng-Hsi; Deziel, Daniel J; Chen, Xiao-Ping; Fan, Sheung Tat; Ker, Chen-Guo; Jonas, Eduard; Padbury, Robert; Mukai, Shuntaro; Honda, Goro; Sugioka, Atsushi; Asai, Koji; Higuchi, Ryota; Wada, Keita; Yoshida, Masahiro; Mayumi, Toshihiko; Hirata, Koichi; Sumiyama, Yoshinobu; Inui, Kazuo; Yamamoto, Masakazu

2018-01-01

Since the publication of the Tokyo Guidelines in 2007 and their revision in 2013, appropriate management for acute cholecystitis has been more clearly established. Since the last revision, several manuscripts, especially for alternative endoscopic techniques, have been reported; therefore, additional evaluation and refinement of the 2013 Guidelines is required. We describe a standard drainage method for surgically high-risk patients with acute cholecystitis and the latest developed endoscopic gallbladder drainage techniques described in the updated Tokyo Guidelines 2018 (TG18). Our study confirmed that percutaneous transhepatic gallbladder drainage should be considered the first alternative to surgical intervention in surgically high-risk patients with acute cholecystitis. Also, endoscopic transpapillary gallbladder drainage or endoscopic ultrasound-guided gallbladder drainage can be considered in high-volume institutes by skilled endoscopists. In the endoscopic transpapillary approach, either endoscopic naso-gallbladder drainage or gallbladder stenting can be considered for gallbladder drainage. We also introduce special techniques and the latest outcomes of endoscopic ultrasound-guided gallbladder drainage studies. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included. © 2017 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

A novel method for estimating methane emissions from underground coal mines: The Yanma coal mine, China

NASA Astrophysics Data System (ADS)

Ji, Zhong-Min; Chen, Zhi-Jian; Pan, Jie-Nan; Niu, Qing-He

2017-12-01

As the world's largest coal producer and consumer, China accounts for a relatively high proportion of methane emissions from coal mines. Several estimation methods had been established for the coal mine methane (CMM) emission. However, with large regional differences, various reservoir formation types of coalbed methane (CBM) and due to the complicated geological conditions in China, these methods may be deficient or unsuitable for all the mining areas (e.g. Jiaozuo mining area). By combing the CMM emission characteristics and considering the actual situation of methane emissions from underground coal mine, we found that the methane pre-drainage is a crucial reason creating inaccurate evaluating results for most estimation methods. What makes it so essential is the extensive pre-drainage quantity and its irrelevance with annual coal production. Accordingly, the methane releases were divided into two categories: methane pre-drainage and methane release during mining. On this basis, a pioneering method for estimating CMM emissions was proposed. Taking the Yanma coal mine in the Jiaozuo mining area as a study case, the evaluation method of the pre-drainage methane quantity was established after the correlation analysis between the pre-drainage rate and time. Thereafter, the mining activity influence factor (MAIF) was first introduced to reflect the methane release from the coal and rock seams around where affected by mining activity, and the buried depth was adopted as the predictor of the estimation for future methane emissions. It was verified in the six coal mines of Jiaozuo coalfield (2011) that the new estimation method has the minimum errors of 12.11%, 9.23%, 5.77%, -5.20%, -8.75% and 4.92% respectively comparing with other methods. This paper gives a further insight and proposes a more accurate evaluation method for the CMM emissions, especially for the coal seams with low permeability and strong tectonic deformation in methane outburst coal mines.

Characterizing the Frequency and Elevation of Rapid Drainage Events in West Greenland

NASA Astrophysics Data System (ADS)

Cooley, S.; Christoffersen, P.

2016-12-01

Rapid drainage of supraglacial lakes on the Greenland Ice Sheet is critical for the establishment of surface-to-bed hydrologic connections and the subsequent transfer of water from surface to bed. Yet, estimates of the number and spatial distribution of rapidly draining lakes vary widely due to limitations in the temporal frequency of image collection and obscureness by cloud. So far, no study has assessed the impact of these observation biases. In this study, we examine the frequency and elevation of rapidly draining lakes in central West Greenland, from 68°N to 72.6°N, and we make a robust statistical analysis to estimate more accurately the likelihood of lakes draining rapidly. Using MODIS imagery and a fully automated lake detection method, we map more than 500 supraglacial lakes per year over a 63000 km2 study area from 2000-2015. Through testing four different definitions of rapidly draining lakes from previously published studies, we find that the number of rapidly draining lakes varies from 3% to 38%. Logistic regression between rapid drainage events and image sampling frequency demonstrates that the number of rapid drainage events is strongly dependent on cloud-free observation percentage. We then develop three new drainage criteria and apply an observation bias correction that suggests a true rapid drainage probability between 36% and 45%, considerably higher than previous studies without bias assessment have reported. We find rapid-draining lakes are on average larger and disappear earlier than slow-draining lakes, and we also observe no elevation differences for the lakes detected as rapidly draining. We conclude a) that methodological problems in rapid drainage research caused by observation bias and varying detection methods have obscured large-scale rapid drainage characteristics and b) that the lack of evidence for an elevation limit on rapid drainage suggests surface-to-bed hydrologic connections may continue to propagate inland as climate warms.

Prospective, randomised, controlled trial comparing suture needle drainage and argon laser drainage of subretinal fluid.

PubMed Central

Aylward, G W; Orr, G; Schwartz, S D; Leaver, P K

1995-01-01

AIMS--This study was designed to compare suture needle drainage (SND) with argon laser drainage (ALD) of subretinal fluid. METHODS--A prospective, randomised, controlled, clinical trial was carried out on 93 patients undergoing external drainage of subretinal fluid during scleral buckling surgery for rhegmatogenous retinal detachment. The incidence of successful drainage, incidence of subretinal haemorrhage, incidence of retinal incarceration, and incidence of retinal perforation were determined. RESULTS--The success rate was 97.9% in the ALD group and 84.8% in the SND group (difference-13.1%, 95% CI-26.4% to 2.0%). The incidence of clinically significant subretinal haemorrhage was 4.3% in the ALD group compared with 28.3% in the SND group (difference 24.0%, 95% CI 7.6% to 40.4%). The incidence of incarceration was comparable in each group. There were no cases of retinal perforation. CONCLUSIONS--The use of ALD was associated with a higher rate of successful SRF drainage, and a lower incidence of clinically significant subretinal haemorrhage than SND. ALD is preferred when an endolaser is available. PMID:7547781

Pre-operative biliary drainage for obstructive jaundice

PubMed Central

Fang, Yuan; Gurusamy, Kurinchi Selvan; Wang, Qin; Davidson, Brian R; Lin, He; Xie, Xiaodong; Wang, Chaohua

2014-01-01

Background Patients with obstructive jaundice have various pathophysiological changes that affect the liver, kidney, heart, and the immune system. There is considerable controversy as to whether temporary relief of biliary obstruction prior to major definitive surgery (pre-operative biliary drainage) is of any benefit to the patient. Objectives To assess the benefits and harms of pre-operative biliary drainage versus no pre-operative biliary drainage (direct surgery) in patients with obstructive jaundice (irrespective of a benign or malignant cause). Search methods We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Clinical Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2012. Selection criteria We included all randomised clinical trials comparing biliary drainage followed by surgery versus direct surgery, performed for obstructive jaundice, irrespective of the sample size, language, and publication status. Data collection and analysis Two authors independently assessed trials for inclusion and extracted data. We calculated the risk ratio (RR), rate ratio (RaR), or mean difference (MD) with 95% confidence intervals (CI) based on the available patient analyses. We assessed the risk of bias (systematic overestimation of benefit or systematic underestimation of harm) with components of the Cochrane risk of bias tool. We assessed the risk of play of chance (random errors) with trial sequential analysis. Main results We included six trials with 520 patients comparing pre-operative biliary drainage (265 patients) versus no pre-operative biliary drainage (255 patients). Four trials used percutaneous transhepatic biliary drainage and two trials used endoscopic sphincterotomy and stenting as the method of pre-operative biliary drainage. The risk of bias was high in all trials. The proportion of patients with malignant obstruction varied between 60% and 100%. There was no significant difference in mortality (40/265, weighted proportion 14.9%) in the pre-operative biliary drainage group versus the direct surgery group (34/255, 13.3%) (RR 1.12; 95% CI 0.73 to 1.71; P = 0.60). The overall serious morbidity was higher in the pre-operative biliary drainage group (60 per 100 patients in the pre-operative biliary drainage group versus 26 per 100 patients in the direct surgery group) (RaR 1.66; 95% CI 1.28 to 2.16; P = 0.0002). The proportion of patients who developed serious morbidity was significantly higher in the pre-operative biliary drainage group (75/102, 73.5%) in the pre-operative biliary drainage group versus the direct surgery group (37/94, 37.4%) (P < 0.001). Quality of life was not reported in any of the trials. There was no significant difference in the length of hospital stay (2 trials, 271 patients; MD 4.87 days; 95% CI −1.28 to 11.02; P = 0.12) between the two groups. Trial sequential analysis showed that for mortality only a small proportion of the required information size had been obtained. There seemed to be no significant differences in the subgroup of trials assessing percutaneous compared to endoscopic drainage. Authors’ conclusions There is currently not sufficient evidence to support or refute routine pre-operative biliary drainage for patients with obstructive jaundice. Pre-operative biliary drainage may increase the rate of serious adverse events. So, the safety of routine pre-operative biliary drainage has not been established. Pre-operative biliary drainage should not be used in patients undergoing surgery for obstructive jaundice outside randomised clinical trials. PMID:22972086

Foliar nutrient concentrations in balsam fir as affected by soil drainage and methods of slash disposal

Treesearch

Miroslaw M. Czapowskyj

1979-01-01

Foliar nutrient concentrations in young balsam fir growing on strip clearcuts were assessed in relation to soil drainage and three methods of slash disposal. Concentrations of N, K, and Mn were higher for trees growing on well-drained soils than for trees growing on poorly drained soils. Mo concentrations were higher on poorly drained soils and all other measured...

Closed-Suction Drainage and Cerebrospinal Fluid Leakage Following Microvascular Decompression : A Retrospective Comparison Study

PubMed Central

Kim, Young-Hoon; Kim, Chae-Yong; Oh, Chang Wan

2013-01-01

Objective We performed this study to investigate whether the use of closed-suction drainage following microvascular decompression (MVD) causes cerebrospinal fluid (CSF) leakage. Methods Between 2004 and 2011, a total of 157 patients with neurovascular compression were treated with MVD. MVD was performed for hemifacial spasm in 150 (95.5%) cases and for trigeminal neuralgia in 7 (4.5%) cases. The mean age of the patients was 49.8±9.6 years (range, 20-69). Dural substitutes were used in 44 (28.0%) patients. Ninety-two patients (58.6%) were underwent a 4-5 cm craniotomy using drainage (drainage group), and 65 (41.4%) did a small 2-2.5 cm retromastoid craniectomy without closed-suction drainage (no-drainage group). Results Eleven (7.0%) patients experienced CSF leakage following MVD based on the criteria of this study; all of these patients were in the drainage group. In the unadjusted analyses, the incidence of CSF leakage was significantly related with the use of closed-suction drainage following MVD (12.0% in the drainage group vs. 0% in the no-drainage group, respectively; p=0.003; Fisher's exact test). Those who received dural substitutes and the elderly (cut-off value=60 years) exhibited a tendency to develop CSF leakage (p=0.075 and p=0.090, respectively; Fisher's exact test). In the multivariate analysis, only the use of closed-suction drainage was significantly and independently associated with the development of CSF leakage following MVD (odds ratio=9.900; 95% confidence interval, 1.418 to infinity; p=0.017). Conclusion The use of closed-suction drainage following MVD appears to be related to the development of CSF leakage. PMID:24175025

Lower incidence of complications in endoscopic nasobiliary drainage for hilar cholangiocarcinoma.

PubMed

Kawakubo, Kazumichi; Kawakami, Hiroshi; Kuwatani, Masaki; Haba, Shin; Kudo, Taiki; Taya, Yoko A; Kawahata, Shuhei; Kubota, Yoshimasa; Kubo, Kimitoshi; Eto, Kazunori; Ehira, Nobuyuki; Yamato, Hiroaki; Onodera, Manabu; Sakamoto, Naoya

2016-05-10

To identify the most effective endoscopic biliary drainage technique for patients with hilar cholangiocarcinoma. In total, 118 patients with hilar cholangiocarcinoma underwent endoscopic management [endoscopic nasobiliary drainage (ENBD) or endoscopic biliary stenting] as a temporary drainage in our institution between 2009 and 2014. We retrospectively evaluated all complications from initial endoscopic drainage to surgery or palliative treatment. The risk factors for biliary reintervention, post-endoscopic retrograde cholangiopancreatography (post-ERCP) pancreatitis, and percutaneous transhepatic biliary drainage (PTBD) were also analyzed using patient- and procedure-related characteristics. The risk factors for bilateral drainage were examined in a subgroup analysis of patients who underwent initial unilateral drainage. In total, 137 complications were observed in 92 (78%) patients. Biliary reintervention was required in 83 (70%) patients. ENBD was significantly associated with a low risk of biliary reintervention [odds ratio (OR) = 0.26, 95%CI: 0.08-0.76, P = 0.012]. Post-ERCP pancreatitis was observed in 19 (16%) patients. An absence of endoscopic sphincterotomy was significantly associated with post-ERCP pancreatitis (OR = 3.46, 95%CI: 1.19-10.87, P = 0.023). PTBD was required in 16 (14%) patients, and Bismuth type III or IV cholangiocarcinoma was a significant risk factor (OR = 7.88, 95%CI: 1.33-155.0, P = 0.010). Of 102 patients with initial unilateral drainage, 49 (48%) required bilateral drainage. Endoscopic sphincterotomy (OR = 3.24, 95%CI: 1.27-8.78, P = 0.004) and Bismuth II, III, or IV cholangiocarcinoma (OR = 34.69, 95%CI: 4.88-736.7, P < 0.001) were significant risk factors for bilateral drainage. The endoscopic management of hilar cholangiocarcinoma is challenging. ENBD should be selected as a temporary drainage method because of its low risk of complications.

Clinical outcomes of percutaneous drainage of breast fluid collections following mastectomy with expander-based breast reconstruction

PubMed Central

2015-01-01

PURPOSE To determine clinical outcomes of patients who underwent imaging-guided percutaneous drainage of breast fluid collections following mastectomy and breast reconstruction. MATERIAL AND METHODS Retrospective review included all consecutive patients who underwent percutaneous drainage of fluid collections following mastectomy with tissue expander-based reconstruction between January 2007 and September 2012. A total of 879 mastectomies (563 patients) with expander-based breast reconstruction were performed during this period. 28 patients (5%) developed fluid collections, which led to 30 imaging-guided percutaneous drainage procedures. The median follow up time was 533 days. Patient characteristics, surgical technique, microbiology analysis, and clinical outcomes were reviewed. RESULTS The mean age was 51.5 years (range 30.9 to 69.4 years) and the median time between breast reconstruction and drainage was 35 days (range 4 to 235 days). Erythema and swelling were the most common presenting symptoms. The median volume of fluid evacuated at the time of drain placement was 70 mL. Drains were left in place for a median 14 days (range 6 to 34 days). Microorganisms were detected in the fluid in 12 of 30 drainage procedures, with Staphylococcus aureus being the most common microorganism. No further intervention was needed in 21 of 30 drainage procedures (70%). However, surgical intervention (removal of expanders) was needed following 6 (20%) drainages, and additional percutaneous drainage procedures were performed following 3 (10%) drainages. CONCLUSION Percutaneous drainage is an effective means of treating post operative fluid collections after expander-based breast reconstruction and can obviate the need for repeat surgery in most cases. PMID:23810309

Mediastinal micro-vessels clipping during lymph node dissection may contribute to reduce postoperative pleural drainage

PubMed Central

Yan, Shi; Wang, Xing; Lv, Chao; Phan, Kevin; Wang, Yuzhao; Wang, Jia; Yang, Yue

2016-01-01

Background Postoperative pleural drainage markedly influences the length of postoperative stay and financial costs of medical care. The aim of this study is to retrospectively investigate potentially predisposing factors related to pleural drainage after curative thoracic surgery and to explore the impact of mediastinal micro-vessels clipping on pleural drainage control after lymph node dissection. Methods From February 2012 to November 2013, 322 consecutive cases of operable non-small cell lung cancers (NSCLC) undergoing lobectomy and mediastinal lymph node dissection with or without application of clipping were collected. Total and daily postoperative pleural drainage were recorded. Propensity score matching (1:2) was applied to balance variables potentially impacting pleural drainage between group clip and group control. Analyses were performed to compare drainage volume, duration of chest tube and postoperative hospital stay between the two groups. Variables linked with pleural drainage in whole cohort were assessed using multivariable logistic regression analysis. Results Propensity score matching resulted in 197 patients (matched cohort). Baseline patient characteristics were matched between two groups. Group clip showed less cumulative drainage volume (P=0.020), shorter duration of chest tube (P=0.031) and postoperative hospital stay (P=0.022) compared with group control. Risk factors significantly associated with high-output drainage in multivariable logistic regression analysis were being male, age >60 years, bilobectomy/sleeve lobectomy, pleural adhesion, the application of clip applier, duration of operation ≥220 minutes and chylothorax (P<0.05). Conclusions This study suggests that mediastinal micro-vessels clipping during lymph node dissection may reduce postoperative pleural drainage and thus shorten hospital stay. PMID:27076936

Pancreatic mediastinal pseudocyst: report of two cases simulating intrathoracic disease.

PubMed

Ahmad, N; Auld, C D; Lawrence, J R; Watson, G D

1991-10-01

Mediastinal pseudocysts of the pancreas are extremely rare. Intra-thoracic symptoms such as dysphagia or dyspnoea due to compression or associated pleural effusions are common and urgent decompression by percutaneous or internal drainage is often necessary.

Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases.

PubMed

Siman, Homayoun; Techy, Fernando

2016-02-01

Study Design Case report. Objective Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperative transcutaneous drainage of a gel-like substance after the use of a dural sealant, which is a previously unreported complication. Methods The clinical course and treatment outcome of two patients is presented. Results Both patients experienced postoperative transcutaneous drainage of a gel-like substance at the surgical site. Case one began draining this substance on postoperative day 14. This patient required no further intervention, and the drainage ended after 3 mL of a gel-like substance was expressed from his incision while in the clinic. Case two began draining the gel on postoperative day 16. This patient underwent two washout procedures and resolution of the drainage. No infection was ever detected. Conclusions To our knowledge, our patients are the first reported cases of transcutaneous drainage of expanded dural sealant. It is important to take into consideration the unexpected expansion of a dural sealant when using it for the repair of IDT.

Transcutaneous Drainage of Gel-Like Substance after Application of Hydrogel Dural Sealant: Report of Two Cases

PubMed Central

Siman, Homayoun; Techy, Fernando

2015-01-01

Study Design Case report. Objective Incidental durotomy (IDT) is a common complication of spinal surgery. The use of collagen matrix graft along with hydrogel dural sealant is a common method of IDT repair. With this method, there have been several reported cases of detrimental dural sealant expansion in the literature. One case study reported an expansion rate greater than 300%; many report neurologic damage. This article reports the clinical course of two patients who developed postoperative transcutaneous drainage of a gel-like substance after the use of a dural sealant, which is a previously unreported complication. Methods The clinical course and treatment outcome of two patients is presented. Results Both patients experienced postoperative transcutaneous drainage of a gel-like substance at the surgical site. Case one began draining this substance on postoperative day 14. This patient required no further intervention, and the drainage ended after 3 mL of a gel-like substance was expressed from his incision while in the clinic. Case two began draining the gel on postoperative day 16. This patient underwent two washout procedures and resolution of the drainage. No infection was ever detected. Conclusions To our knowledge, our patients are the first reported cases of transcutaneous drainage of expanded dural sealant. It is important to take into consideration the unexpected expansion of a dural sealant when using it for the repair of IDT. PMID:26835216

The optimal protocol to reduce blood loss and blood transfusion after unilateral total knee replacement: Low-dose IA-TXA plus 30-min drain clamping versus drainage clamping for the first 3 h without IA-TXA.

PubMed

Park, Joo Hyun; Choi, Sung Wook; Shin, Eun Ho; Park, Myung Hoon; Kim, Myung Ku

2017-01-01

Although intraarticular tranexamic acid (IA-TXA) administration or drainage clamping are popular methods used to reduce blood loss after total knee replacement (TKR), the protocol remains controversial. We aimed (1) to establish new protocols through investigating whether two methods, that is, low-dose (500 mg) IA-TXA plus 30-min drain clamping and drainage clamping for the first 3 h without IA-TXA, can reduce blood loss and blood transfusion after unilateral TKR and (2) to make recommendations related to clinical application. This study, conducted from September 2014 to June 2016 related to enrolled 95 patients with primary osteoarthritis who were to have a unilateral cemented TKR, was nonrandomized and retrospective. In group A, the drain was released following tourniquet deflation. In group B, 500-mg TXA was injected into the knee joint via a drain tube after fascia closure and the drain was clamped for the first 30 min to prevent leakage. In group C, the drain was clamped for the first 3-h postoperation. Demographic characteristics and clinical data were collected, including the levels of hematocrit (Hct), the total blood loss (TBL), drained blood volume (BV), the amount of blood transfused, and any complications that developed. We found a significantly lower postoperative TBL, drained BV, decreasing Hct level, and less transfused BV in the IA-TXA injection group (group B) and the 3-h drainage clamping group (group C) compared to the conventional negative drainage group (group A; p < 0.001). There was no significant difference between groups B and C ( p = 0.99). The drainage clamping method can be safer than IA-TXA administration in patients with risk factor of venous thromboembolic complication. Furthermore, the IA-TXA administration can be more optimal than drainage clamping in patients with high bleeding tendency or lateral retinacular release during TKR, who would be concerned about postoperative wound complication.

Evaluation of pore-water samplers at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

USGS Publications Warehouse

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used innovative sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report evaluates a new type of pore-water sampler developed for this investigation to examine the subsurface contamination beneath the drainage ditch. The new type of pore-water sampler appears to be an effective approach for long-term monitoring of ground water in the sand and organic-rich mud beneath the drainage ditch.

[Endoscopic realignment with drainage via a peel-away sheath for the treatment of urethral rupture: A report of 21 cases].

PubMed

Han, Cong-Xiang; Xu, Wei-Jie; Li, Wei; Yu, Zhong-Ying; Li, Jin-Yu; Lin, Xia-Cong; Zhao, Li

2016-07-01

To study the clinical effect endoscopic realignment with drainage via a peel-away sheath in the treatment of urethral rupture. We treated 21 urethral rupture patients by endoscopic realignment with drainage via a peel-away sheath using normal saline for irrigation under the normal nephroscope or Li Xun nephroscope, followed by analysis of the clinical results. The operation was successfully accomplished in 20 cases but failed in 1 and none experienced urinary extravasation. In the 14 cases of bulbar urethral rupture, the mean operation time was (5.1±1.6) min and the mean Foley catheter indwelling time was (26.0±5.1) d. Urethral stricture developed in 57.1% (8/14) of the cases after catheter removal, of which 1 was cured by internal urethrotomy and the other 7 by urethral sound dilation, with an average maximum urinary flow rate of (18.8±1.8) ml/s at 12 months after operation. In the 6 cases of posterior urethral rupture, the mean operation time was (15.8±7.5) min and the mean Foley catheter indwelling time was 8 weeks. Urethral stricture developed in all the 6 cases after catheter removal, of which 3 cases were cured by urethral dilation, 1 by internal urethrotomy, and 2 by open urethroplasty. The average maxium urinary flow rate of the 4 cases exempt from open surgery was (17.9±1.9) ml/s at 12 months after operation. Endoscopic realignment with drainage via a peel-away sheath can keep the operative field clear, avoid intraoperative rinse extravasation, shorten the operation time, improve the operation success rate, and achieve satisfactory early clinical outcomes in the treatment of either bulbar or posterior urethral rupture.

Endoscopic ultrasound-guided transluminal drainage for peripancreatic fluid collections: where are we now?

PubMed

Kawakami, Hiroshi; Itoi, Takao; Sakamoto, Naoya

2014-07-01

Endoscopic drainage for pancreatic and peripancreatic fluid collections (PFCs) has been increasingly used as a minimally invasive alternative to surgical or percutaneous drainage. Recently, endoscopic ultrasound-guided transluminal drainage (EUS-TD) has become the standard of care and a safe procedure for nonsurgical PFC treatment. EUS-TD ensures a safe puncture, avoiding intervening blood vessels. Single or multiple plastic stents (combined with a nasocystic catheter) were used for the treatment of PFCs for EUS-TD. More recently, the use of covered self-expandable metallic stents (CSEMSs) has provided a safer and more efficient approach route for internal drainage. We focused our review on the best approach and stent to use in endoscopic drainage for PFCs. We reviewed studies of EUS-TD for PFCs based on the original Atlanta Classification, including case reports, case series, and previous review articles. Data on clinical outcomes and adverse events were collected retrospectively. A total of 93 patients underwent EUS-TD of pancreatic pseudocysts using CSEMSs. The treatment success and adverse event rates were 94.6% and 21.1%, respectively. The majority of complications were of mild severity and resolved with conservative therapy. A total of 56 patients underwent EUS-TD using CSEMSs for pancreatic abscesses or infected walled-off necroses. The treatment success and adverse event rates were 87.8% and 9.5%, respectively. EUS-TD can be performed safely and efficiently for PFC treatment. Larger diameter CSEMSs without additional fistula tract dilation for the passage of a standard scope are needed to access and drain for PFCs with solid debris.

Rapidly changing subglacial hydrological pathways at a tidewater glacier revealed through simultaneous observations of water pressure, supraglacial lakes, meltwater plumes and surface velocities

NASA Astrophysics Data System (ADS)

How, Penelope; Benn, Douglas I.; Hulton, Nicholas R. J.; Hubbard, Bryn; Luckman, Adrian; Sevestre, Heïdi; van Pelt, Ward J. J.; Lindbäck, Katrin; Kohler, Jack; Boot, Wim

2017-11-01

Subglacial hydrological processes at tidewater glaciers remain poorly understood due to the difficulty in obtaining direct measurements and lack of empirical verification for modelling approaches. Here, we investigate the subglacial hydrology of Kronebreen, a fast-flowing tidewater glacier in Svalbard during the 2014 melt season. We combine observations of borehole water pressure, supraglacial lake drainage, surface velocities and plume activity with modelled run-off and water routing to develop a conceptual model that thoroughly encapsulates subglacial drainage at a tidewater glacier. Simultaneous measurements suggest that an early-season episode of subglacial flushing took place during our observation period, and a stable efficient drainage system effectively transported subglacial water through the northern region of the glacier tongue. Drainage pathways through the central and southern regions of the glacier tongue were disrupted throughout the following melt season. Periodic plume activity at the terminus appears to be a signal for modulated subglacial pulsing, i.e. an internally driven storage and release of subglacial meltwater that operates independently of marine influences. This storage is a key control on ice flow in the 2014 melt season. Evidence from this work and previous studies strongly suggests that long-term changes in ice flow at Kronebreen are controlled by the location of efficient/inefficient drainage and the position of regions where water is stored and released.

Specific Yield--Column drainage and centrifuge moisture content

USGS Publications Warehouse

Johnson, A.I.; Prill, R.C.; Morris, D.A.

1963-01-01

The specific yield of a rock or soil, with respect to water, is the ratio of (1) the volume of water which, after being saturated, it will yield by gravity to (2) its own volume. Specific retention represents the water retained against gravity drainage. The specific yield and retention when added together are equal to the total interconnected porosity of the rock or soil. Because specific retention is more easily determined than specific yield, most methods for obtaining yield first require the determination of specific retention. Recognizing the great need for developing improved methods of determining the specific yield of water-bearing materials, the U.S. Geological Survey and the California Department of Water Resources initiated a cooperative investigation of this subject. The major objectives of this research are (1) to review pertinent literature on specific yield and related subjects, (2) to increase basic knowledge of specific yield and rate of drainage and to determine the most practical methods of obtaining them, (3) to compare and to attempt to correlate the principal laboratory and field methods now commonly used to obtain specific yield, and (4) to obtain improved estimates of specific yield of water-bearing deposits in California. An open-file report, 'Specific yield of porous media, an annotated bibliography,' by A. I. Johnson, D. A. Morris, and R. C. Prill, was released in 1960 in partial fulfillment of the first objective. This report describes the second phase of the specific-yield study by the U.S. Geological Survey Hydrologic Laboratory at Denver, Colo. Laboratory research on column drainage and centrifuge moisture equivalent, two methods for estimating specific retention of porous media, is summarized. In the column-drainage study, a wide variety of materials was packed into plastic columns of 1- to 8-inch diameter, wetted with Denver tap water, and drained under controlled conditions of temperature and humidity. The effects of cleaning the porous media; of different column diameters; of dye and time on drainage; and of different methods of drainage, wetting, and packing were all determined. To insure repeatability of porosity in duplicate columns, a mechanical technique of packing was developed. In the centrifuge moisture-content study, the centrifuge moisture-equivalent (the moisture content retained by a soil that has been first saturated and then subjected to a force equal to 1,000 times the force of gravity for 1 hour) test was first reviewed and evaluated. It was determined that for reproducible moisture-retention results the temperature and humidity should be controlled by use of a controlled-temperature centrifuge. In addition to refining this standard test, the study determined the effect of length of period of centrifuging and of applied tension on the drainage results. The plans for future work require the continuation of the laboratory standardization study qith emphasis on investigation of soil-moisture tension and unsaturated-permeability techniques. A detailed study in the field then will be followed by correlation and evaluation of laboratory and field methods.

Burr-hole Irrigation with Closed-system Drainage for the Treatment of Chronic Subdural Hematoma: A Meta-analysis

PubMed Central

XU, Chen; CHEN, Shiwen; YUAN, Lutao; JING, Yao

2016-01-01

There is controversy among neurosurgeons regarding whether irrigation or drainage is necessary for achieving a lower revision rate for the treatment of chronic subdural hematoma (CSDH) using burr-hole craniostomy (BHC). Therefore, we performed a meta-analysis of all available published reports. Multiple electronic health databases were searched to identify all studies published between 1989 and June 2012 that compared irrigation and drainage. Data were processed by using Review Manager 5.1.6. Effect sizes are expressed as pooled odds ratio (OR) estimates. Due to heterogeneity between studies, we used the random effect of the inverse variance weighted method to perform the meta-analysis. Thirteen published reports were selected for this meta-analysis. The comprehensive results indicated that there were no statistically significant differences in mortality or complication rates between drainage and no drainage (P > 0.05). Additionally, there were no differences in recurrence between irrigation and no irrigation (P > 0.05). However, the difference between drainage and no drainage in recurrence rate reached statistical significance (P < 0.01). The results from this meta-analysis suggest that burr-hole surgery with closed-system drainage can reduce the recurrence of CSDH; however, irrigation is not necessary for every patient. PMID:26377830

Comparison of Medpor Coated Tear Drainage Tube versus Silicon Tear Drainage Tube in Conjunctivodacryocystorhinostomy: Problems and Solutions

PubMed Central

Sendul, Selam Yekta; Cagatay, Halil Huseyin; Dirim, Burcu; Demir, Mehmet; Yıldız, Ali Atakhan; Acar, Zeynep; Cinar, Sonmez; Guven, Dilek

2014-01-01

Purpose. This study aims at comparing two different types of drainage tubes in conjunctivodacryocystorhinostomy, which are used for upper lacrimal system obstruction or damage, with respect to their respective postoperative problems and solutions. Methods. Nineteen eyes of 17 patients who underwent conjunctivodacryocystorhinostomy (CDCR) or conjunctivorhinostomy (CR) surgery with a Medpor coated tear drainage tube or silicon tube placement between October, 2010, and February, 2014, were included in this retrospective comparative study. Results. In the initial surgery, Medpor coated tear drainage tubes were used in 11 eyes by CDCR, whereas silicon tear drainage tubes were implanted into 2 eyes by CR and 6 eyes by CDCR. In group 1, proximal and distal obstructions developed postoperatively in 4 eyes, while 1 eye showed tube malposition and 3 eyes developed luminal obstruction by debris 3 times. In group 2, tube extrusion developed in 4 eyes, whereas tube malposition developed in 6 eyes and luminal obstruction by debris developed in 6 eyes at different times, for a total of 20 times. Conclusions. In our study, the most significant complication we observed in the use of silicon tear drainage tubes was tube extrusion,whereas the leading complication related to the use of Medpor coated tear drainage tubes was tube obstruction. PMID:25379518

Linking soil type and rainfall characteristics towards estimation of surface evaporative capacitance

NASA Astrophysics Data System (ADS)

Or, D.; Bickel, S.; Lehmann, P.

2017-12-01

Separation of evapotranspiration (ET) to evaporation (E) and transpiration (T) components for attribution of surface fluxes or for assessment of isotope fractionation in groundwater remains a challenge. Regional estimates of soil evaporation often rely on plant-based (Penman-Monteith) ET estimates where is E is obtained as a residual or a fraction of potential evaporation. We propose a novel method for estimating E from soil-specific properties, regional rainfall characteristics and considering concurrent internal drainage that shelters soil water from evaporation. A soil-dependent evaporative characteristic length defines a depth below which soil water cannot be pulled to the surface by capillarity; this depth determines the maximal soil evaporative capacitance (SEC). The SEC is recharged by rainfall and subsequently emptied by competition between drainage and surface evaporation (considering canopy interception evaporation). We show that E is strongly dependent on rainfall characteristics (mean annual, number of storms) and soil textural type, with up to 50% of rainfall lost to evaporation in loamy soil. The SEC concept applied to different soil types and climatic regions offers direct bounds on regional surface evaporation independent of plant-based parameterization or energy balance calculations.

Endoscopic transmural management of abdominal fluid collection following gastrointestinal, bariatric, and hepato-bilio-pancreatic surgery.

PubMed

Donatelli, Gianfranco; Fuks, David; Cereatti, Fabrizio; Pourcher, Guillaume; Perniceni, Thierry; Dumont, Jean-Loup; Tuszynski, Thierry; Vergeau, Bertrand Marie; Meduri, Bruno; Gayet, Brice

2018-05-01

Post-operative collections are a recognized source of morbidity after abdominal surgery. Percutaneous drainage is currently considered the standard treatment but not all collections are accessible using this method. Since the adoption of EUS, endoscopic transmural drainage has become an attractive option in the management of such complications. The present study aimed to assess the efficacy, safety and modalities of endoscopic transmural drainage in the treatment of post-operative collections. Data of all patients referred to our dedicated multidisciplinary facility from 2014 to 2017 for endoscopic drainage of symptomatic post-operative collections after failure of percutaneous drainage or when it was deemed impossible, were retrospectively analyzed. Thirty-two patients (17 males and 15 females) with a median age of 53 years old (range 31-74) were included. Collections resulted from pancreatic (n = 10), colorectal (n = 6), bariatric (n  = 5), and other type of surgery (n  = 11). Collection size was less than 5 cm in diameter in 10 (31%), between 5 and 10 cm in 17 (53%) ,and more than 10 cm in 5 (16%) patients. The median time from surgery to endoscopic drainage was 38 days (range 6-360). Eight (25%) patients underwent endoscopic guided drainage whereas 24 (75%) patients underwent EUS-guided drainage. Technical success was 100% and clinical success was achieved in 30 (93.4%) after a mean follow-up of 13.5 months (1.2-24.8). Overall complication was 12.5% including four patients who bled following trans-gastric drainage treated with conservative therapy. The present series suggests that endoscopic transmural drainage represents an interesting alternative in the treatment of post-operative collection when percutaneous drainage is not possible or fails.

Systematic review and meta-analysis of prophylactic abdominal drainage after pancreatic resection

PubMed Central

Dou, Chang-Wei; Liu, Zhi-Kui; Jia, Yu-Li; Zheng, Xin; Tu, Kang-Sheng; Yao, Ying-Min; Liu, Qing-Guang

2015-01-01

AIM: To investigate whether prophylactic abdominal drainage is necessary after pancreatic resection. METHODS: PubMed, Web of Science, and the Cochrane Library were systematically searched to obtain relevant articles published before January 2014. Publications were retrieved if they met the selection criteria. The outcomes of interest included: mortality, morbidity, postoperative pancreatic fistula (POPF), clinically relevant pancreatic fistula (CR-PF), abdominal abscess, reoperation rate, the rate of interventional radiology drainage, and the length of hospital stay. Subgroup analyses were also performed for pancreaticoduodenectomy (PD) and for distal pancreatectomy. Begg’s funnel plot and the Egger regression test were employed to assess potential publication bias. RESULTS: Nine eligible studies involving a total of 2794 patients were identified and included in this meta-analysis. Of the included patients, 1373 received prophylactic abdominal drainage. A fixed-effects model meta-analysis showed that placement of prophylactic drainage did not have beneficial effects on clinical outcomes, including morbidity, POPF, CR-PF, reoperation, interventional radiology drainage, and length of hospital stay (Ps > 0.05). In addition, prophylactic drainage did not significantly increase the risk of abdominal abscess. Overall analysis showed that omitting prophylactic abdominal drainage resulted in higher mortality after pancreatectomy (OR = 1.56; 95%CI: 0.93-2.92). Subgroup analysis of PD showed similar results to those in the overall analysis. Elimination of prophylactic abdominal drainage after PD led to a significant increase in mortality (OR = 2.39; 95%CI: 1.22-4.69; P = 0.01). CONCLUSION: Prophylactic abdominal drainage after pancreatic resection is still necessary, though more evidence from randomized controlled trials assessing prophylactic drainage after PD and distal pancreatectomy are needed. PMID:25987799

Surgical management of complicated hydatid cysts of the liver

PubMed Central

Malik, Ajaz A; Bari, Shams UL; Amin, Ruquia; Jan, Masooda

2010-01-01

AIM: To review the clinical presentation and surgical management of complicated hydatid cysts of the liver and to assess whether conservative surgery is adequate in the management of complicated hydatid cysts of liver. METHODS: The study was carried out at Sher-i-Kashmir Institute of Medical Science, Srinagar, Kashmir, India. Sixty nine patients with hydatid disease of the liver were surgically managed from April 2004 to October 2005 with a follow up period of three years. It included 27 men and 42 women with a median age of 35 years. An abdominal ultrasound, computed tomography and serology established diagnosis. Patients with jaundice and high suspicion of intrabiliary rupture were subjected to preoperative endoscopic retrograde cholangiography. Cysts with infection, rupture into the biliary tract and peritoneal cavity were categorized as complicated cysts. Eighteen patients (26%) had complicated cysts and formed the basis for this study. RESULTS: Common complications were infection (14%), intrabiliary rupture (9%) and intraperitoneal rupture (3%). All the patients with infected cysts presented with pain and fever. All the patients with intrabiliary rupture had jaundice, while only four with intrabiliary rupture had pain and only two had fever. Surgical procedures performed in complicated cysts were: infection-omentoplasty in three and external drainage in seven; intrabiliary rupture-omentoplasty in two and internal drainage in four patients. Two patients with intraperitoneal rupture underwent external drainage. There was no mortality. The postoperative morbidity was 50% in complicated cysts and 16% in uncomplicated cysts. CONCLUSION: Complicated hydatid cyst of the liver can be successfully managed surgically with good long term results. PMID:21160854

How large is the Upper Indus Basin? The pitfalls of auto-delineation using DEMs

NASA Astrophysics Data System (ADS)

Khan, Asif; Richards, Keith S.; Parker, Geoffrey T.; McRobie, Allan; Mukhopadhyay, Biswajit

2014-02-01

Extraction of watershed areas from Digital Elevation Models (DEMs) is increasingly required in a variety of environmental analyses. It is facilitated by the availability of DEMs based on remotely sensed data, and by Geographical Information System (GIS) software. However, accurate delineation depends on the quality of the DEM and the methodology adopted. This paper considers automated and supervised delineation in a case study of the Upper Indus Basin (UIB), Pakistan, for which published estimates of the basin area show significant disagreement, ranging from 166,000 to 266,000 km2. Automated delineation used ArcGIS Archydro and hydrology tools applied to three good quality DEMs (two from SRTM data with 90m resolution, and one from 30m resolution ASTER data). Automatic delineation defined a basin area of c.440,000 km2 for the UIB, but included a large area of internal drainage in the western Tibetan Plateau. It is shown that discrepancies between different estimates reflect differences in the initial extent of the DEM used for watershed delineation, and the unchecked effect of iterative pit-filling of the DEM (going beyond the filling of erroneous pixels to filling entire closed basins). For the UIB we have identified critical points where spurious addition of catchment area has arisen, and use Google Earth to examine the geomorphology adjacent to these points, and also examine the basin boundary data provided by the HydroSHEDS database. We show that the Pangong Tso watershed and some other areas in the western Tibetan plateau are not part of the UIB, but are areas of internal drainage. Our best estimate of the area of the Upper Indus Basin (at Besham Qila) is 164,867 km2 based on the SRTM DEM, and 164,853 km2 using the ASTER DEM). This matches the catchment area measured by WAPDA SWHP. An important lesson from this investigation is that one should not rely on automated delineation, as iterative pit-filling can produce spurious drainage networks and basins, when there are areas of internal drainage nearby.

Methods for estimating flow-duration and annual mean-flow statistics for ungaged streams in Oklahoma

USGS Publications Warehouse

Esralew, Rachel A.; Smith, S. Jerrod

2010-01-01

Flow statistics can be used to provide decision makers with surface-water information needed for activities such as water-supply permitting, flow regulation, and other water rights issues. Flow statistics could be needed at any location along a stream. Most often, streamflow statistics are needed at ungaged sites, where no flow data are available to compute the statistics. Methods are presented in this report for estimating flow-duration and annual mean-flow statistics for ungaged streams in Oklahoma. Flow statistics included the (1) annual (period of record), (2) seasonal (summer-autumn and winter-spring), and (3) 12 monthly duration statistics, including the 20th, 50th, 80th, 90th, and 95th percentile flow exceedances, and the annual mean-flow (mean of daily flows for the period of record). Flow statistics were calculated from daily streamflow information collected from 235 streamflow-gaging stations throughout Oklahoma and areas in adjacent states. A drainage-area ratio method is the preferred method for estimating flow statistics at an ungaged location that is on a stream near a gage. The method generally is reliable only if the drainage-area ratio of the two sites is between 0.5 and 1.5. Regression equations that relate flow statistics to drainage-basin characteristics were developed for the purpose of estimating selected flow-duration and annual mean-flow statistics for ungaged streams that are not near gaging stations on the same stream. Regression equations were developed from flow statistics and drainage-basin characteristics for 113 unregulated gaging stations. Separate regression equations were developed by using U.S. Geological Survey streamflow-gaging stations in regions with similar drainage-basin characteristics. These equations can increase the accuracy of regression equations used for estimating flow-duration and annual mean-flow statistics at ungaged stream locations in Oklahoma. Streamflow-gaging stations were grouped by selected drainage-basin characteristics by using a k-means cluster analysis. Three regions were identified for Oklahoma on the basis of the clustering of gaging stations and a manual delineation of distinguishable hydrologic and geologic boundaries: Region 1 (western Oklahoma excluding the Oklahoma and Texas Panhandles), Region 2 (north- and south-central Oklahoma), and Region 3 (eastern and central Oklahoma). A total of 228 regression equations (225 flow-duration regressions and three annual mean-flow regressions) were developed using ordinary least-squares and left-censored (Tobit) multiple-regression techniques. These equations can be used to estimate 75 flow-duration statistics and annual mean-flow for ungaged streams in the three regions. Drainage-basin characteristics that were statistically significant independent variables in the regression analyses were (1) contributing drainage area; (2) station elevation; (3) mean drainage-basin elevation; (4) channel slope; (5) percentage of forested canopy; (6) mean drainage-basin hillslope; (7) soil permeability; and (8) mean annual, seasonal, and monthly precipitation. The accuracy of flow-duration regression equations generally decreased from high-flow exceedance (low-exceedance probability) to low-flow exceedance (high-exceedance probability) . This decrease may have happened because a greater uncertainty exists for low-flow estimates and low-flow is largely affected by localized geology that was not quantified by the drainage-basin characteristics selected. The standard errors of estimate of regression equations for Region 1 (western Oklahoma) were substantially larger than those standard errors for other regions, especially for low-flow exceedances. These errors may be a result of greater variability in low flow because of increased irrigation activities in this region. Regression equations may not be reliable for sites where the drainage-basin characteristics are outside the range of values of independent vari

CT Fluoroscopy-Guided Transsacral Intervertebral Drainage for Pyogenic Spondylodiscitis at the Lumbosacral Junction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsumoto, Tomohiro, E-mail: t-matsu@tokai-u.jp; Mine, Takahiko, E-mail: mine@tsc.u-tokai.ac.jp; Hayashi, Toshihiko, E-mail: t.hayashi@tokai.ac.jp

PurposeTo retrospectively describe the feasibility and efficacy of CT fluoroscopy-guided transsacral intervertebral drainage for pyogenic spondylodiscitis at the lumbosacral junction with a combination of two interventional radiological techniques—CT-guided bone biopsy and abscess drainage.Materials and methodsThree patients with pyogenic spondylodiscitis at the lumbosacral junction were enrolled in this study between July 2013 and December 2015. The procedure of CT fluoroscopy-guided transsacral intervertebral drainage for pyogenic spondylodiscitis at the lumbosacral junction was as follows: the sacrum at S1 pedicle was penetrated with an 11-gauge (G) bone biopsy needle to create a path for an 8-French (F) pigtail drainage catheter. The bone biopsymore » needle was withdrawn, and an 18-G needle was inserted into the intervertebral space of the lumbosacral junction. Then, a 0.038-inch guidewire was inserted into the intervertebral space. Finally, the 8-F pigtail drainage catheter was inserted over the guidewire until its tip reached the intervertebral space. All patients received six-week antibiotics treatment.ResultsSuccessful placement of the drainage catheter was achieved for each patient without procedural complications. The duration of drainage was 17–33 days. For two patients, specific organisms were isolated; thus, definitive medical therapy was possible. All patients responded well to the treatment.ConclusionsCT fluoroscopy-guided transsacral intervertebral drainage for pyogenic spondylodiscitis at the lumbosacral junction is feasible and can be effective with a combination of two interventional techniques—CT fluoroscopy-guided bone biopsy and abscess drainage.« less

Comparison of Natural Drainage Group and Negative Drainage Groups after Total Thyroidectomy: Prospective Randomized Controlled Study

PubMed Central

Woo, Seung Hoon; Kim, Jin Pyeong; Park, Jung Je; Shim, Hyun Seok; Lee, Sang Ha; Lee, Ho Joong; Won, Seong Jun; Son, Hee Young; Kim, Rock Bum

2013-01-01

Purpose The aim of this study was to compare a negative pressure drain with a natural drain in order to determine whether a negative pressure drainage tube causes an increase in the drainage volume. Materials and Methods Sixty-two patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) were enrolled in the study between March 2010 and August 2010 at Gyeongsang National University Hospital. The patients were prospectively and randomly assigned to two groups, a negative pressure drainage group (n=32) and natural drainage group (n=30). Every 3 hours, the volume of drainage was checked in the two groups until the tube was removed. Results The amount of drainage during the first 24 hours postoperatively was 41.68±3.93 mL in the negative drain group and 25.3±2.68 mL in the natural drain group (p<0.001). After 24 additional hours, the negative drain group was 35.19±4.26 mL and natural drain groups 21.53±2.90 mL (p<0.001). However, the drainage at postoperative day 3 was not statistically different between the two groups. In addition, the vocal cord palsy and temporary and permanent hypocalcemia were not different between the two groups. Conclusion These results indicate that a negative pressure drain may increase the amount of drainage during the first 24-48 hours postoperatively. Therefore, it is not necessary to place a closed suction drain when only a total thyroidectomy is done. PMID:23225820

Micro-scale elemental partition in tissues of the aquatic plant Lemna minor L. exposed to highway drainage water

NASA Astrophysics Data System (ADS)

Mendes Godinho, R.; Raimundo, J.; Vale, C.; Anes, B.; Brito, P.; Alves, L. C.; Pinheiro, T.

2013-07-01

In the scope of a monitoring program to assess the environmental impact of automobile traffic over one main bridge in Lisbon, both water and duckweed (Lemna minor L.) were sampled from the road drainage tanks and analyzed for chemical elements. Plants uptake Cr, Mn, Cu, and Zn metals from rain water draining the bridge road. Nuclear microprobe elemental maps of cryosections of L. minor tissues showed that incorporated elements were internalized in fronds of the plant. This approach at micrometer level allows a better knowledge of the elemental tissue partitioning in this biomonitor organism.

Profiling USGA putting greens using GPR - an as-built surveying method

USDA-ARS?s Scientific Manuscript database

Golf course greens that are constructed to U.S. Golf Association (USGA) standards must adhere to strict installation specifications in order to maintain proper subsurface drainage. Because the infrastructure is buried, it can be difficult to ascertain if these drainage pipes were properly installed...

RESPIROMETRY AS A TOOL TO DETERMINE METAL TOXICITY IN A SULFATE REDUCING BACTERIAL CULTURE

EPA Science Inventory

A novel method under development for treatment of acid mine drainage waste uses biologically- generated hydrogen sulfide (H2S) to precipitate the metals in acid mine drainage (principally zinc, copper, aluminum, nickel, cadmium, arsenic, manganese, iron, and cobalt). The insolub...

Assessment of Agricultural Drainage Pipe Conditions Using Ground Penetrating Radar

USDA-ARS?s Scientific Manuscript database

Farmers and land improvement contractors, especially in the Midwest U.S., need methods to not only locate buried agricultural drainage pipe, but also to determine if the pipes are functioning properly with respect to water delivery. Previous investigations have already demonstrated the feasibility o...

Capturing Flow-weighted Water and Suspended Particulates from Agricultural Canals During Drainage Events.

PubMed

Bhadha, Jehangir H; Sexton, Anne; Lang, Timothy A; Daroub, Samira H

2017-11-07

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage discharge events. Farm canals can be enriched by nutrients such as phosphorus (P) that are susceptible to transport. Phosphorus in the form of suspended particulates can significantly contribute to the overall P loads in drainage water. A settling tank experiment was conducted to capture suspended particulates during discrete drainage events. Farm canal discharge water was collected in a series of two 200 L settling tanks over the entire duration of the drainage event, so as to represent a composite subsample of the water being discharged. Imhoff settling cones are ultimately used to settle out the suspended particulates. This is achieved by siphoning water from the settling tanks via the cones. The particulates are then collected for physico-chemical analyses.

Removal of phosphorus from agricultural wastewaters using adsorption media prepared from acid mine drainage sludge

USGS Publications Warehouse

Sibrell, Philip L.; Montgomery, Gary A.; Ritenour, Kelsey L.; Tucker, Travis W.

2009-01-01

Excess phosphorus in wastewaters promotes eutrophication in receiving waterways. A??cost-effective method for the removal of phosphorus from water would significantly reduce the impact of such wastewaters on the environment. Acid mine drainage sludge is a waste product produced by the neutralization of acid mine drainage, and consists mainly of the same metal hydroxides used in traditional wastewater treatment for the removal of phosphorus. In this paper, we describe a method for the drying and pelletization of acid mine drainage sludge that results in a particulate media, which we have termed Ferroxysorb, for the removal of phosphorus from wastewater in an efficient packed bed contactor. Adsorption capacities are high, and kinetics rapid, such that a contact time of less than 5 min is sufficient for removal of 60-90% of the phosphorus, depending on the feed concentration and time in service. In addition, the adsorption capacity of the Ferroxysorb media was increased dramatically by using two columns in an alternating sequence so that each sludge bed receives alternating rest and adsorption cycles. A stripping procedure based on treatment with dilute sodium hydroxide was also developed that allows for recovery of the P from the media, with the possibility of generating a marketable fertilizer product. These results indicate that acid mine drainage sludges - hitherto thought of as undesirable wastes - can be used to remove phosphorus from wastewater, thus offsetting a portion of acid mine drainage treatment costs while at the same time improving water quality in sensitive watersheds.

A comparative study of treatments for chronic subdural hematoma: burr hole drainage versus burr hole drainage with irrigation.

PubMed

Ishibashi, Akira; Yokokura, Yoshitake; Adachi, Hisashi

2011-01-01

Although chronic subdural hematoma (CSDH) is one of the most common entities encountered in neurosurgical practice, optimal surgical treatment for CSDH remains controversial. This study retrospectively compared results for CSDH between burr hole drainage alone and burr hole drainage with irrigation. Ninety-two patients with CSDH underwent surgery at our institution from January 1998 through December 2009. Fifty-eight patients received burr hole drainage alone (Group A), while 34 patients were treated using burr hole drainage with irrigation (Group B). Outcomes, recurrence rates, and death rates for the two groups were analyzed. Age, sex ratio, consciousness level on admission, radiodensity of hematoma on computed tomography before surgery, and duration of hospitalization were nearly the same in both groups. No significant differences were seen in good outcomes or death rates between groups, but poor outcomes were significantly more frequent in Group A (p=0.009). The recurrence rate was higher in Group A compared to Group B (10.3% vs. 2.9%). The authors used logistic regression analysis to identify factors associated with the outcome of CSDH, and found that duration of hospital stay, anti-coagulant therapy, presence of dementia and burr hole drainage alone were significantly associated with poor outcome of CSDH. These results indicate that burr hole drainage with irrigation has a significantly stronger association with good outcomes compared to drainage alone, and could be a reliable and effective operative method for the treatment of CSDH with a lower recurrence rate.

Tile Drainage Expansion Detection using Satellite Soil Moisture Dynamics

NASA Astrophysics Data System (ADS)

Jacobs, J. M.; Cho, E.; Jia, X.

2017-12-01

In the past two decades, tile drainage installation has accelerated throughout the Red River of the North Basin (RRB) in parts of western Minnesota, eastern North Dakota, and a small area of northeastern South Dakota, because the flat topography and low-permeability soils in this region necessitated the removal of excess water to improve crop production. Interestingly, streamflow in the Red River has markedly increased and six of 13 major floods during the past century have occurred since the late 1990s. It has been suggested that the increase in RRB flooding could be due to change in agricultural practices, including extensive tile drainage installation. Reliable information on existing and future tile drainage installation is greatly needed to capture the rapid extension of tile drainage systems and to locate tile drainage systems in the north central U.S. including the RRB region. However, there are few reliable data of tile drainage installation records, except tile drainage permit records in the Bois de Sioux watershed (a sub-basin in southern part of the RRB where permits are required for tile drainage installation). This study presents a tile drainage expansion detection method based on a physical principle that the soil-drying rate may increase with increasing tile drainage for a given area. In order to capture the rate of change in soil drying rate with time over entire RRB (101,500 km2), two satellite-based microwave soil moisture records from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and AMSR2 were used during 2002 to 2016. In this study, a sub-watershed level (HUC10) potential tile drainage growth map was developed and the results show good agreement with tile drainage permit records of six sub-watersheds in the Bois de Sioux watershed. Future analyses will include improvement of the potential tile drainage map through additional information using optical- and thermal-based sensor products and evaluation of its hydrological impacts on intensity, duration, and frequency of extreme streamflow from watershed to basin scale.

A new automated passive capillary lysimeter for logging real-time drainage water fluxes

USDA-ARS?s Scientific Manuscript database

Effective monitoring of chemical transport through the soil profile requires accurate and appropriate instrumentation to measure drainage water fluxes below the root zone of cropping system. The objectives of this study were to methodically describe in detail the construction and installation of a n...

Investigation of ground-water contamination at a drainage ditch, Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, 2005–06

USGS Publications Warehouse

Vroblesky, Don A.; Casey, Clifton C.

2007-01-01

The U.S. Geological Survey, in cooperation with the Naval Facilities Engineering Command Southeast, used newly developed sampling methods to investigate ground-water contamination by chlorobenzenes beneath a drainage ditch on the southwestern side of Installation Restoration Site 4, Naval Air Station Corpus Christi, Corpus Christi, Texas, during 2005-06. The drainage ditch, which is a potential receptor for ground-water contaminants from Installation Restoration Site 4, intermittently discharges water to Corpus Christi Bay. This report uses data from a new type of pore-water sampler developed for this investigation and other methods to examine the subsurface contamination beneath the drainage ditch. Analysis of ground water from the samplers indicated that chlorobenzenes (maximum detected concentration of 160 micrograms per liter) are present in the ground water beneath the ditch. The concentrations of dissolved oxygen in the samples (less than 0.05-0.4 milligram per liter) showed that the ground water beneath and near the ditch is anaerobic, indicating that substantial chlorobenzene biodegradation in the aquifer beneath the ditch is unlikely. Probable alternative mechanisms of chlorobenzene removal in the ground water beneath the drainage ditch include sorption onto the organic-rich sediment and contaminant depletion by cattails through uptake, sorption, and localized soil aeration.

Experimental study of the moisture distribution on the wetting front during drainage and imbibition in a 2D sand chamber

NASA Astrophysics Data System (ADS)

Wei, Yunbo; Chen, Kouping; Wu, Jichun; Zhu, Xiaobin

2018-06-01

In the present study, the moisture distribution on the wetting front during drainage and imbibition in a 2D sand chamber is studied thoroughly. Based on the high-resolution data measured by light transmission method, the moisture distribution is observed and then analyzed quantitatively. During drainage and imbibition, different moisture distributions are observed: (a) during drainage, moisture contents fluctuate in a larger range and fingers can be seen on the wetting front; (b) while during imbibition, moisture contents fluctuate in a smaller range and the wetting front is more regular. The Hurst coefficients are successful in capturing different characteristics of the moisture distribution between drainage and imbibition. During imbibition, the Hurst coefficients are around 0.2 on the wetting front; while during drainage, the Hurst coefficients are around 0.5. As the porosity changes from 0.336 to 0.383, the moisture distribution in the sand chamber does not display obvious change. While as the imbibition rate increases from 5 ml/min to 400 ml/min, the moisture distribution on the wetting front becomes more uniform.

A high-vacuum wound drainage system reduces pain and length of treatment for pediatric soft tissue abscesses.

PubMed

Yang, Chao; Wang, Shan; Li, Chang-Chun; Kong, Xiang-Ru; Zhao, Zhenzhen; Deng, Xiao-Bin; Peng, Liang; Zhang, Jun

2017-02-01

Open incision and drainage (I&D) and wound packing is accepted as the standard treatment for soft tissue abscesses. However, conventional I&D has a number of problems in practice which prompt us to improve the I&D methods that would minimize the pain associated with packing during dressing changes. In order to compare the pain associated with dressing changes in the conventional I&D group to the vacuum system group and the treatment time of both groups, we performed a randomized trial in pediatric patients between 0 and 18 years of age who are undergoing abscess drainage in the operating room from April 2011 to April 2015. Patients treated with open I&D (n = 648) were compared to those treated with placement of high-vacuum wound drainage system (n = 776) through the abscess cavities. Both groups received equivalent antibiotic treatment, and all patients were followed up in the outpatient clinics until the infection has been resolved. The mean FACES scale pain scores were significantly higher in the open I&D group than in the vacuum system group. The vacuum system group had a shorter length of stay and less need for community doctor or outpatient dressing changes than the open I&D group (p < 0.001). No recurrent abscesses were observed in the vacuum system group, and 10 patients in the open I&D group required another drainage at the exact same location. High-vacuum wound drainage system was an efficient and safe alternative to the traditional I&D for community-acquired soft tissue abscesses with few complications in short term. What is Known: • Open incision and drainage (I&D) followed by irrigation and wound packing is the standard treatment for soft tissue abscesses. • The painful daily packing may cause emotional trauma to the child and lead to an unwelcoming challenge to the caretakers and health care providers. What is New: • We modified the method of I&D by adding primary suturing of the wound and placement of a high-vacuum wound drainage system. • This technique was proved to be an efficient and safe alternative to the traditional I&D method for soft tissue abscesses with small complications in short term.

Effect of Woody Vegetation on Hydraulic Conductivity at Various Levee Systems Using Numerical Models

DTIC Science & Technology

2012-06-01

XIX International Conference on Water Resources CMWR 2012 University of Illinois at Urbana -Champaign June 17-22, 2012 1 EFFECT OF WOODY...distribution unlimited 13. SUPPLEMENTARY NOTES Presented at the XIX International Conference on Water Resources CMWR 2012, Urbana -Champaign, IL, June...the Pocket and Burlington levees, the lower toe for the Portland levee, and the bottom of the dewatered drainage ditch for the Albuquerque levee

The role of contact angle on unstable flow formation during infiltration and drainage in wettable porous media

NASA Astrophysics Data System (ADS)

Wallach, Rony; Margolis, Michal; Graber, Ellen R.

2013-10-01

The impact of contact angle on 2-D spatial and temporal water-content distribution during infiltration and drainage was experimentally studied. The 0.3-0.5 mm fraction of a quartz dune sand was treated and turned subcritically repellent (contact angle of 33°, 48°, 56°, and 75° for S33, S48, S56, and S75, respectively). The media were packed uniformly in transparent flow chambers and water was supplied to the surface as a point source at different rates (1-20 ml/min). A sequence of gray-value images was taken by CCD camera during infiltration and subsequent drainage; gray values were converted to volumetric water content by water volume balance. Narrow and long plumes with water accumulation behind the downward moving wetting front (tip) and negative water gradient above it (tail) developed in the S56 and S75 media during infiltration at lower water application rates. The plumes became bulbous with spatially uniform water-content distribution as water application rates increased. All plumes in these media propagated downward at a constant rate during infiltration and did not change their shape during drainage. In contrast, regular plume shapes were observed in the S33 and S48 media at all flow rates, and drainage profiles were nonmonotonic with a transition plane at the depth that water reached during infiltration. Given that the studied media have similar pore-size distributions, the conclusion is that imbibition hindered by the nonzero contact angle induced pressure buildup at the wetting front (dynamic water-entry value) that controlled the plume shape and internal water-content distribution during infiltration and drainage.

EARLYDRAIN- outcome after early lumbar CSF-drainage in aneurysmal subarachnoid hemorrhage: study protocol for a randomized controlled trial.

PubMed

Bardutzky, Jürgen; Witsch, Jens; Jüttler, Eric; Schwab, Stefan; Vajkoczy, Peter; Wolf, Stefan

2011-09-14

Aneurysmal subarachnoid hemorrhage (SAH) may be complicated by delayed cerebral ischemia, which is a major cause of unfavorable clinical outcome and death in SAH-patients. Delayed cerebral ischemia is presumably related to the development of vasospasm triggered by the presence of blood in the basal cisterns. To date, oral application of the calcium antagonist nimodipine is the only prophylactic treatment for vasospasm recognized under international guidelines.In retrospective trials lumbar drainage of cerebrospinal fluid has been shown to be a safe and feasible measure to remove the blood from the basal cisterns and decrease the incidence of delayed cerebral ischemia and vasospasm in the respective study populations. However, the efficacy of lumbar drainage has not been evaluated prospectively in a randomized controlled trial yet. This is a protocol for a 2-arm randomized controlled trial to compare an intervention group receiving early continuous lumbar CSF-drainage and standard neurointensive care to a control group receiving standard neurointensive care only. Adults suffering from a first aneurysmal subarachnoid hemorrhage whose aneurysm has been secured by means of coiling or clipping are eligible for trial participation. The effect of early CSF drainage (starting < 72 h after securing the aneurysm) will be measured in the following ways: the primary endpoint will be disability after 6 months, assessed by a blinded investigator during a personal visit or standardized telephone interview using the modified Rankin Scale. Secondary endpoints include mortality after 6 months, angiographic vasospasm, transcranial Doppler sonography (TCD) mean flow velocity in both middle cerebral arteries and rate of shunt insertion at 6 months after hospital discharge. Here, we present the study design of a multicenter prospective randomized controlled trial to investigate whether early application of a lumbar drainage improves clinical outcome after aneurysmal subarachnoid hemorrhage.

Spontaneous pneumothorax; a multicentre retrospective analysis of emergency treatment, complications and outcomes.

PubMed

Brown, S G A; Ball, E L; Macdonald, S P J; Wright, C; McD Taylor, D

2014-05-01

Spontaneous pneumothorax can be managed initially by observation, aspiration or chest drain insertion. To determine the clinical features of spontaneous pneumothorax in patients presenting to the emergency department (ED), interventions, outcomes and potential risk factors for poor outcomes after treatment. Retrospective chart review from ED of three major referral and two general hospitals in Australia of presentations with primary spontaneous pneumothorax (PSP) or secondary spontaneous pneumothorax (SSP). Main outcomes were prolonged air leak (>5 days) and pneumothorax recurrence within 1 year. We identified 225 people with PSP and 98 with SSP. There were no clinical tension pneumothoraces with hypotension. Hypoxaemia (haemoglobin oxygen saturation measured by pulse oximetry ≤92%) occurred only in SSP and in older patients (age >50 years) with PSP. Drainage was performed in 150 (67%) PSP and 82 (84%) SSP. Prolonged air leak occurred in 16% (95% confidence interval 10-23%) of PSP and 31% (21-42%) of SSP. Independent risk factors for prolonged drainage were non-asthma SSP and pneumothorax size >50%. Complications were recorded in 11% (7.5-16%) of those having drains inserted. Recurrences occurred in 5/91 (5%, 1.8-12%) of those treated without drainage versus 40/232 (17%, 13-23%) of those treated by drainage, of which half occurred in the first month after drainage. Pneumothorax drainage is associated with substantial morbidity including prolonged air leak. As PSP appears to be well tolerated in younger people even with large pneumothoraces, conservative treatment in this subgroup may be a viable option to improve patient outcomes, but this needs to be confirmed in a clinical trial. © 2014 The Authors; Internal Medicine Journal © 2014 Royal Australasian College of Physicians.

Ballistics and the management of ureteral injuries from high velocity missiles.

PubMed

Stutzman, R E

1977-12-01

The management of 21 patients with 22 ureteral injuries from high velocity missiles is described and 6 cases are reported in detail. Ballistics should be considered in all wounds of violence. Débridement, internal stents, proximal diversion and thorough drainage are advocated.

An Approach to Assessing Flood Risk in Low-lying Paddy Areas of Japan considering Economic Damage on Rice

NASA Astrophysics Data System (ADS)

Minakawa, H.; Masumoto, T.

2013-12-01

Hiroki Minakawa, Takao Masumoto National Institute for Rural Engineering (NIRE), NARO, Japan Flooding is one type of nature disaster, and is caused by heavy rainfall events. In the future, the risk of flooding is predicted to increase due to global climate change. Immediate measures such as strengthening drainage capacity are needed to minimize the damage caused by more frequent flooding, so a quantitative evaluation method of flood risks is needed to discuss countermeasure against these problems. At the same time, rice is an important crop for food production in Japan. However, paddy fields are often damaged by flooding because they are principally spread in lower part of the basin. Therefore, it is also important to assess the damages to paddy fields. This study discusses a method for evaluating a relationship between the risk of flood damage and the scale of heavy rainfall. We also developed a method of estimating the economic effect of a reduction in rice yield by flooding. First, we developed a drainage analysis model that incorporates kinematic and diffusive runoff models for calculating water level in channels and paddies. Next, heavy rainfall data for drainage analyses were generated by using a diurnal rainfall pattern generator. The generator can create hourly data of heavy rainfall, and internal pattern of them is different each. These data were input to the drainage model to estimate flood risk. Simultaneously, we tried to clarify economic losses of a rice yields caused by flooding. Here, the reduction scale in rice yield which shows relations between flooding situation (e.g. water level, duration of submersion etc.) and damage of rice is available to calculate reduction of rice yield. In this study, we created new reduction scales through a pseudo-flooding experiment under real inundation conditions. The methodology of the experiment was as follow: We chose the popular Japanese rice cultivar Koshihikari for this experiment. An experimental arena was constructed in a rice paddy plot, which consisted of two zones, one in which the rice was cultivated as usual with normal water levels, and a flood zone, which was used for submerging rice plants. The flood zone, which was designed to reproduce actual flood disaster conditions in paddy fields, can be filled with water to a depth of 0.3, 0.6 or 0.9 m above ground level, and is divided into two plots, a clean water part and a turbid water part. Thus, the experimental conditions can vary according to 1) the development stage of rice, 2) complete or incomplete submersion, 3) clean or turbid water, and 4) duration of submergence. Finally, the reduction scales were formulated by using the resultant data and it was found that rice is most sensitive to damage during the development stage. Flood risk was evaluated by using calculated water level on each paddy. Here, the averaged duration of inundation to a depth of more than 0.3 m was used as the criteria for flood occurrence. The results indicated that the duration increased with larger heavy rainfall amounts. Furthermore, the damage to rice was predicted to increase especially in low-lying paddy fields. Mitigation measures, such as revising drainage planning and/or changing design standards for the capacity of drainage pumps may be necessary in the future.

A comparative assessment of irrigation and drainage characteristics for commercially available urethral catheters

PubMed Central

Davis, Niall F.; McMahon, Barry P.; Walsh, Michael; McDermott, Thomas E.D.; Thornhill, John A.; Manecksha, Rustom P.

2017-01-01

Introduction We aimed to investigate irrigation and drainage characteristics of commercially available urethral catheters and determined which catheter offers the best flow characteristics. Material and methods Twelve different commercially available urethral catheters from three companies (Bard™, Rusch™ and Dover™) were investigated to compare their irrigation and drainage properties. Irrigation port, drainage port and overall cross-sectional areas for a 24Fr 3-way catheter was measured and compared. The maximum (Qmax) and average (Qavg) irrigation and drainage flow rates for each catheter was measured for 20–40 seconds using uroflowmetry. The primary endpoint was to determine which catheter offers optimal irrigation and drainage parameters. Results Overall cross-sectional area, irrigation port cross-sectional area, and drainage port cross-sectional area differed significantly for each 24Fr 3-way catheter assessed (p <0.001). The 24Fr 3-way Rusch Simplastic™ catheter consistently demonstrated the greatest maximal flow rate (Qmax: 5 ±0.3 ml/s) and average flow rate (Qavg: 4.6 ±0.2 ml/s) for irrigation. The 24Fr 3-way Dover™ catheter provided the greatest drainage properties (Qmax: 19.7 ±2 ml/s; Q avg: 15.9 ±5 ml/s). In the setting of continuous bladder irrigation, the 24Fr 3-way Rusch Simplastic™ catheter provided the highest irrigation rates (Qmax: 6.6 ±1.8 ml/s; Q avg: 4.6 ±0.9 ml/s). Conclusions Three-way catheters demonstrate significant differences in their irrigation and drainage characteristics. The type of catheter selected should be based on the appropriate prioritization of efficient bladder irrigation versus efficient bladder drainage. PMID:29410890

Impact of tile drainage on evapotranspiration in South Dakota, USA, based on high spatiotemporal resolution evapotranspiration time series from a multi-satellite data fusion system

USGS Publications Warehouse

Yang, Yun; Anderson, Martha C.; Gao, Feng; Hain, Christopher; Kustas, William P.; Meyers, Tilden P.; Crow, Wade; Finocchiaro, Raymond G.; Otkin, Jason; Sun, Liang; Yang, Yang

2017-01-01

Soil drainage is a widely used agricultural practice in the midwest USA to remove excess soil water to potentially improve the crop yield. Research shows an increasing trend in baseflow and streamflow in the midwest over the last 60 years, which may be related to artificial drainage. Subsurface drainage (i.e., tile) in particular may have strongly contributed to the increase in these flows, because of its extensive use and recent gain in the popularity as a yield-enhancement practice. However, how evapotranspiration (ET) is impacted by tile drainage on a regional level is not well-documented. To explore spatial and temporal ET patterns and their relationship to tile drainage, we applied an energy balance-based multisensor data fusion method to estimate daily 30-m ET over an intensively tile-drained area in South Dakota, USA, from 2005 to 2013. Results suggest that tile drainage slightly decreases the annual cumulative ET, particularly during the early growing season. However, higher mid-season crop water use suppresses the extent of the decrease of the annual cumulative ET that might be anticipated from widespread drainage. The regional water balance analysis during the growing season demonstrates good closure, with the average residual from 2005 to 2012 as low as -3 mm. As an independent check of the simulated ET at the regional scale, the water balance analysis lends additional confidence to the study. The results of this study improve our understanding of the influence of agricultural drainage practices on regional ET, and can affect future decision making regarding tile drainage systems.

[One-stage operation for pelvis and acetabular fractures combined with Morel-Lavallée injury by internal fixation associated with vacuum sealing drainage].

PubMed

Wei, Dan; Wang, Yue; Yuan, Jiabin; Tang, Xiaoming; Zhang, Bin; Lu, Bing; Tan, Bo

2014-01-01

To investigate the methods and effectiveness of one-stage operation for pelvis and acetabular fractures combined with Morel-Lavallée injury by internal fixation associated with vacuum sealing drainage (VSD). Between June 2008 and October 2012, 15 cases of pelvis and acetabular fractures combined with Morel-Lavallée injury were treated. There were 5 males and 10 females, aged from 18 to 67 years (mean, 36.8 years). Fractures were caused by traffic accident in 11 cases and crashing injury of heavy object in 4 cases. The time from injury to hospitalization was 3 hours to 9 days (mean, 5.4 days). Morel-Lavallée injury located in the above posterior superior iliac spine in 4 cases, greater trochanter in 7 cases, and anterior proximal thigh in 4 cases. In 10 cases complicated by pelvic fracture, there were 1 case of anteroposterior compression type, 3 cases of lateral compression type, 5 cases of vertical shear type, and 1 case of compound injury type; in 5 cases complicated by acetabular fracture, there were 1 case of transverse fracture, 1 case of posterior wall and posterior column fracture, 1 case of transverse acetabulum plus posterior wall fracture, and 2 cases of both columns fracture. Open reduction and internal fixation were used to treat pelvic and acetabular fractures, and VSD to treat Morel-Lavallée injury. When the drainage volume was less than 20 mL/d, interrupted wound suture or free skin grafting was performed. The hospitalization time was 16-31 days (mean, 20.8 days). Thirteen cases were followed up 4-16 months (mean, 7.8 months). The healing time of Morel-Lavallée injury was 16-36 days after operation (mean, 21.3 days). All the wounds had primary healing, and no infection occurred. The X-ray films showed that all fractures healed, with a mean healing time of 13.6 weeks (range, 11-18 weeks). At 6.5 months after operation, according to Majeed function scoring system in 8 cases of pelvic fracture, the results were excellent in 5 cases, good in 2 cases, and fair in 1 case; according to Harris hip scoring in 4 cases of acetabular fracture, the results were excellent in 2 cases, good in 1 case, and fair in 1 case. To pelvis-acetabular fractures combined with Morel-Lavallée injury, internal fixation treatment for fracture and VSD for Morel-Lavallée injury not only can cure merge Morel-Lavallée injury effectively, but also can guarantee the operation timing and incision safty of the pelvis-acetabular fractures.

Drainage of malignant ascites: patient selection and perspectives

PubMed Central

Stukan, Maciej

2017-01-01

Malignant ascites (MA) is a sign of advanced cancer and poor prognosis. MA can result in impairment in quality of life (QOL) and significant symptoms. As a supportive treatment, ascites can be drained by paracentesis (PC), percutaneously implanted catheters (tunneled, untunneled, central venous catheters), or peritoneal ports, or peritoneovenous shunts. The aim of this study was to evaluate the effectiveness, safety, and patient-reported outcomes (PRO) of different drainage methods for the management of MA. A systematic review of the literature was performed, and 32 original articles met the inclusion criteria. Patients selected for permanent drain insertion demonstrated symptoms related to MA and had undergone repeated PC. The primary focus of the reviewed articles was procedural safety issues. The rate of technical success of drainage device installation was 100%. Most patients experienced improvements in symptom control after ascites drainage. When analyzed together, 19.7% (255/1297) of patients experienced any complication and 6.2% (81/1297) experienced serious adverse events during MA drainage. Complications were reported for every drainage method; however, the least occurred after PC or central venous catheter, while the most serious occurred after peritoneovenous shunts. Adverse events were as follows: catheter obstruction: 4.4%, infection: 4.1%, leakage: 3.5%, catheter dislodgment: 2.3%, hypotension: 0.6%, injuries during device insertion: 0.6%, renal impairment: 0.5%, electrolyte imbalance: 0.2%, other: 3.6%. PRO and QOL endpoints were available for 12 studies. When PRO were measured using an interview, a significant improvement in symptom control and QOL was reported in almost all patients. Once standardized questionnaires were used, improvements in symptomatic scores and role functioning were observed. Deterioration was observed in cognitive and emotional subscales. MA drainage is a safe and effective method to control symptoms associated with ascites, and should be perceived as a supportive care, that can be applied for those who need it at any time of their cancer trajectory. Patient selection should be performed using a thorough assessment of symptoms and QOL, and should not be delayed. PMID:28442933

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takizawa, Kenji, E-mail: khirari@marianna-u.ac.jp; Nakajima, Yasuo, E-mail: nakajima.yasuo@gmail.com; Ogawa, Yukihisa, E-mail: yukky.oct.22@gmail.com

Purpose: The authors devised a new method of an axial puncture approach through the pulmonary apex (PA) for percutaneous catheter drainage (PCD) of loculated fluid collections extending to the PA. The purpose of this report is to introduce the new procedure. Methods: Percutaneous catheter drainage by the axial puncture approach was performed in two patients with limited supine position and loculated pleural fluid collection in the posteromedial part of thoracic cavity. Results: The procedures succeeded in two patients without difficulties while keeping them in a supine position, even if the loculated fluids exist in the posterior side of thoracic cavity.more » Conclusions: Percutaneous catheter drainage by the axial puncture approach is particularly effective in patients with limited supine positions and loculated pleural fluid collection in the posteromedial part of thoracic cavity.« less

Controls on drainage divide migration in the northern Sierras Pampeanas assessed through morphometric indicators

NASA Astrophysics Data System (ADS)

Seagren, E. G.; Schoenbohm, L. M.

2017-12-01

Drainage reorganization, primarily through progressive divide migration leading to discrete stream captures, is increasingly recognized as a common phenomenon during mountain-building events. This drainage rearrangement reflects complex interactions between tectonics, climate, and lithology, and can fundamentally change erosion and sedimentation patterns; therefore, determining the spatial extent and potential controls of divide migration is vital to understanding the topographic evolution of orogenic landscapes. Both geomorphic and morphometric evidence can be used to identify such drainage reorganization. The northern Sierras Pampeanas is an ideal location in which to study divide migration as limited glaciation and low out-of-channel erosion rates preserve evidence of reorganization. Additionally, several ranges in the region, such as Sierra de las Planchadas, exhibit geomorphic evidence of drainage rearrangement, including wind gaps and hairpin turns. Using ArcGIS, LSDTopoTools, and TopoToolbox, we conducted a systematic analysis of the spatial distribution of three morphometric indicators of divide migration: χ, Mx, and local headwater relief. Local `hotspots' undergoing drainage divide migration were identified using spatial autocorrelation and clustering methods - Gi* and Moran's I. Using spatial regression analysis, we assessed the potential controls of lithology, modern TRMM precipitation rates, and tectonics over divide migration. Preliminary results suggest broad westward migration of main drainage divides, following both the orographic precipitation gradient and regional slope.

Inferring tectonic activity using drainage network and RT model: an example from the western Himalayas, India

NASA Astrophysics Data System (ADS)

Sahoo, Ramendra; Jain, Vikrant

2017-04-01

Morphology of the landscape and derived features are regarded to be an important tool for inferring about tectonic activity in an area, since surface exposures of these subsurface processes may not be available or may get eroded away over time. This has led to an extensive research in application of the non-planar morphological attributes like river long profile and hypsometry for tectonic studies, whereas drainage network as a proxy for tectonic activity has not been explored greatly. Though, significant work has been done on drainage network pattern which started in a qualitative manner and over the years, has evolved to incorporate more quantitative aspects, like studying the evolution of a network under the influence of external and internal controls. Random Topology (RT) model is one of these concepts, which elucidates the connection between evolution of a drainage network pattern and the entropy of the drainage system and it states that in absence of any geological controls, a natural population of channel networks will be topologically random. We have used the entropy maximization principle to provide a theoretical structure for the RT model. Furthermore, analysis was carried out on the drainage network structures around Jwalamukhi thrust in the Kangra reentrant in western Himalayas, India, to investigate the tectonic activity in the region. Around one thousand networks were extracted from the foot-wall (fw) and hanging-wall (hw) region of the thrust sheet and later categorized based on their magnitudes. We have adopted the goodness of fit test for comparing the network patterns in fw and hw drainage with those derived using the RT model. The null hypothesis for the test was, the drainage networks in the fw are statistically more similar than those on the hw, to the network patterns derived using the RT model for any given magnitude. The test results are favorable to our null hypothesis for networks with smaller magnitudes (< 9), whereas for larger magnitudes, both hw and fw networks were found to be statistically not similar to the model network patterns. Calculation of pattern frequency for each magnitude and subsequent hypothesis testing were carried out using Matlab (v R2015a). Our results will help to define drainage network pattern as one of the geomorphic proxy to identify tectonically active area. This study also serve as a supplementary proof of the neo-tectonic control on the morphology of landscape and its derivatives around the Jwalamukhi thrust. Additionally, it will help to verify the theory of probabilistic evolution of drainage networks.

Population Pharmacokinetics of Combined Intravenous and Local Intrathecal Administration of Meropenem in Aneurysm Patients with Suspected Intracranial Infections After Craniotomy.

PubMed

Li, Xingang; Sun, Shusen; Wang, Qiang; Zhao, Zhigang

2018-02-01

For patients with intracranial infection, local intrathecal administration of meropenem may be a useful method to obtain a sufficient drug concentration in the cerebral spinal fluid (CSF). However, a large inter-individual variability may pose treatment efficacy at risk. This study aimed to identify factors affecting drug concentration in the CSF using population pharmacokinetics method. After craniotomy, aneurysm patients with an indwelling lumbar cistern drainage tube who received a combined intravenous and intrathecal administration of meropenem for the treatment of suspected intracranial infection were enrolled. Venous blood and CSF specimens were collected for determining meropenem concentrations. Nonlinear mixed-effects modeling method was used to fit blood and CSF concentrations simultaneously and to develop the population pharmacokinetic model. The proposed model was applied to simulate dosage regimens. A three-compartmental model was established to describe meropenem in vivo behavior. Lumbar CSF drainage resulted in a drug loss, and drug clearance in CSF (CL CSF ) was employed to describe this. The covariate analysis found that the drainage volume (mL/day) was strongly associated with CL CSF , and the effect of creatinine clearance was significant on the clearance of meropenem in blood (CL). Visual predictive check suggested that the proposed pharmacokinetic model agreed well with the observations. Simulation showed that both intravenous and intrathecal doses should be increased with the increases of minimum inhibitory concentration and daily CSF drainage volume. This model incorporates covariates of the creatinine clearance and the drainage volume, and a simple to use dosage regimen table was created to guide clinicians with meropenem dosing.

Black Walnut Growth Better on Deep, Well-Drained BottomLand Soils

Treesearch

Craig K. Losche

1973-01-01

Site requirements of 25-year-old plantation-grown black walnut on floodplains in southern Illinois were studied. Depth to a gravel layer was the only soil factor that significantly influenced height growth. There was a relationship between internal soil drainage and height growth.

Subdural drainage versus subperiosteal drainage in burr-hole trepanation for symptomatic chronic subdural hematomas.

PubMed

Bellut, David; Woernle, Christoph Michael; Burkhardt, Jan-Karl; Kockro, Ralf Alfons; Bertalanffy, Helmut; Krayenbühl, Niklaus

2012-01-01

Symptomatic chronic subdural hematoma (scSDH) is one of the most frequent diseases in neurosurgical practice, and its incidence is increasing. However, treatment modalities are still controversial. The aim of this retrospective single-center study is to compare for the first time two surgical methods in the treatment of subdural hematoma that have been proven to be efficient in previous studies in a direct comparison. We analyzed the data of 143 scSDHs in 113 patients undergoing surgery for subdural hematoma with placement of subperiosteal or subdural drainage after double burr-hole trepanation for hematoma evacuation. Overall, there were no statistically significant differences regarding general patient characteristics, preoperative and postoperative symptoms, postoperative hematoma remnant, rates of recurrences, mortality, complications, and outcome at discharge and at 3-month follow up between the groups. There was a close to significant tendency of lower mortality after placement of subperiosteal drainage system and a tendency towards lower rate of recurrent hematoma after placement of subdural drainage system. Our study shows for the first time a direct comparison of two mainly used surgical techniques in the treatment of scSDH. Both methods proved to be highly effective, and general patient data, complications, outcome and mortality of both groups are equal or superior compared with previously published series. Because there is a clear tendency to less mortality and fewer serious complications, treatment with double burr-hole trepanation, irrigation, and placement of subperiosteal drainage is our treatment of choice in patients with predictable high risk of complications. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST): a protocol for a multicentre randomised controlled trial

PubMed Central

Kato, Shin; Kuwatani, Masaki; Sugiura, Ryo; Sano, Itsuki; Kawakubo, Kazumichi; Ono, Kota; Sakamoto, Naoya

2017-01-01

Introduction The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naïve major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. Methods and analysis We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. Ethics and dissemination This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016–0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. Trial registration number The University Hospital Medical Information Network ID: UMIN000025727 Pre-results. PMID:28801436

Treatment Approach for Infection of Healed Fractures After Internal Fixation.

PubMed

Lawrenz, Joshua M; Frangiamore, Salvatore J; Rane, Ajinkya A; Cantrell, William Alex; Vallier, Heather A

2017-11-01

To review the efficacy of a treatment approach for patients with infection and colonized implants after open reduction and internal fixation of fractures. Retrospective case series. Level one trauma center. Twenty patients were treated for wound infection with colonized implants after open reduction and internal fixation. Surgical debridement, removal of implants, and a short postoperative oral antibiotic course. The course of patients after surgical debridement and removal of implants, including culture results, antibiotic administration, and presence of recurrent clinical infection and radiographic union. Twenty patients had clinical presentations, including skin breakdown, serous drainage, purulent drainage and/or exposed implants, most commonly of the tibia (15 of 20). Mean time from index procedure to debridement with implant removal was 19.7 months. At the time of debridement and implant removal, 18 of 20 (90%) patients had a positive intraoperative culture (16 routine cultures and 2 broth cultures). The most common bacteria were Enterobacter cloacae (5/17) and methicillin-sensitive Staphylococcus aureus (4/17). All patients had soft tissue healing without signs of recurrent infection after mean follow up of 40 months after implant removal. Surgical debridement with implant removal plus a short oral antibiotic course is effective to resolve wound infection with a colonized implant in the setting of healed fracture after internal fixation. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cost utility analysis of endoscopic biliary stent in unresectable hilar cholangiocarcinoma: decision analytic modeling approach.

PubMed

Sangchan, Apichat; Chaiyakunapruk, Nathorn; Supakankunti, Siripen; Pugkhem, Ake; Mairiang, Pisaln

2014-01-01

Endoscopic biliary drainage using metal and plastic stent in unresectable hilar cholangiocarcinoma (HCA) is widely used but little is known about their cost-effectiveness. This study evaluated the cost-utility of endoscopic metal and plastic stent drainage in unresectable complex, Bismuth type II-IV, HCA patients. Decision analytic model, Markov model, was used to evaluate cost and quality-adjusted life year (QALY) of endoscopic biliary drainage in unresectable HCA. Costs of treatment and utilities of each Markov state were retrieved from hospital charges and unresectable HCA patients from tertiary care hospital in Thailand, respectively. Transition probabilities were derived from international literature. Base case analyses and sensitivity analyses were performed. Under the base-case analysis, metal stent is more effective but more expensive than plastic stent. An incremental cost per additional QALY gained is 192,650 baht (US$ 6,318). From probabilistic sensitivity analysis, at the willingness to pay threshold of one and three times GDP per capita or 158,000 baht (US$ 5,182) and 474,000 baht (US$ 15,546), the probability of metal stent being cost-effective is 26.4% and 99.8%, respectively. Based on the WHO recommendation regarding the cost-effectiveness threshold criteria, endoscopic metal stent drainage is cost-effective compared to plastic stent in unresectable complex HCA.

Scleral electrocautery and its effects on choroid vessels: implications for subretinal fluid drainage during scleral buckling surgery.

PubMed

Roybal, C Nathaniel; Tsui, Irena; Sanfilippo, Christian; Hubschman, Jean-Pierre

2013-01-01

External drainage of subretinal fluid as part of a scleral buckling procedure rapidly restores the retinal pigment epithelium-neural retina interface in rhegmatogenous retinal detachments but carries the inherent risk of subretinal hemorrhage and retinal incarceration. The authors investigated variations to the technique to reduce the chance of subretinal hemorrhage originating from the choroid. A novel method for needle drainage using electrocautery of the sclerochoroidal layers before puncture was employed. The effect of 0% to 50% scleral electrocautery in a porcine model was investigated. A significant decrease in choroidal vessel diameter and choroidal vessel density at 40% electrocautery was demonstrated. Electrocautery without scleral cut-down before external drainage of subretinal fluid likely decreases the chance of subretinal hemorrhage by decreasing choroidal vascularity. Copyright 2013, SLACK Incorporated.

New technique for treating pseudocyst of the auricle.

PubMed

Zhu, L X; Wang, X Y

1990-01-01

Although pseudocyst of the auricle is a common disease in China, its cause and mechanism are still not clear. Several methods of treatment have been advocated: repeated aspirations combined with physiotherapy, and incision and drainage with contour pressure dressing, magnetotherapy etc. In recent years, a new technique with a drainage tube inserted into the pseudocyst using a guide needle has been used in our hospital in the treatment of this condition. We report 45 cases treated by this method, none of whom had the condition previously.

The usefulness of Wi-Fi based digital chest drainage system in the post-operative care of pneumothorax.

PubMed

Cho, Hyun Min; Hong, Yoon Joo; Byun, Chun Sung; Hwang, Jung Joo

2016-03-01

Chest drainage systems are usually composed of chest tube and underwater-seal bottle. But this conventional system may restrict patients doing exercise and give clinicians obscure data about when to remove tubes because there is no objective indicator. Recently developed digital chest drainage systems may facilitate interpretation of the grade of air leak and make it easy for clinicians to decide when to remove chest tubes. In addition, with combination of wireless internet devices, monitoring and managing of drainage system distant from the patient is possible. Sixty patients of primary pneumothorax were included in a prospective randomized study and divided into two groups. Group I (study) consisted of digital chest drainage system while in group II (control), conventional underwater-seal chest bottle system was used. Data was collected from January, 2012 to September, 2013 in Eulji University Hospital, Daejeon, Korea. There was no difference in age, sex, smoking history and postoperative pain between two groups. But the average length of drainage was 2.2 days in group I and 3.1 days in group II (P<0.006). And more, about 90% of the patients in group I was satisfied with using new device for convenience. Digital system was beneficial on reducing the length of tube drainage by real time monitoring. It also had advantage in portability, loudness and gave more satisfaction than conventional system. Moreover, internet based digital drainage system will be a good method in thoracic telemedicine area in the near future.

Effects of lumbar drainage on CSF dynamics in subarachnoid hemorrhage condition: A computational study.

PubMed

Abolfazli, Ehsan; Fatouraee, Nasser; Seddighi, Amir Saeed

2016-10-01

Lumbar drainage is considered a therapeutic measure in treatment of subarachnoid hemorrhage. However, the evidence on the effectiveness of this method is still inconclusive. In this study, a subject-specific three dimensional model of the cerebrospinal fluid (CSF) pathways and compartments was developed. The ventricular and the cranial and spinal subarachnoid spaces were reconstructed using magnetic resonance images. Occurrence of subarachnoid hemorrhage was modeled. Since the presence of blood in the CSF spaces is known to be the cause of complications such as cerebral vasospasm, concentration of blood in these spaces was investigated. Two cases of lumbar drains that were different in the drainage rate were studied. Temporal variations of concentration of blood in CSF spaces were calculated. It was observed that lumbar drainage accelerates the clearance of blood and, thereby, the spasmogens present in the cranial and spinal subarachnoid space. Higher clearance rates were observed at higher drainage rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of different uncertainty techniques in urban stormwater quantity and quality modelling.

PubMed

Dotto, Cintia B S; Mannina, Giorgio; Kleidorfer, Manfred; Vezzaro, Luca; Henrichs, Malte; McCarthy, David T; Freni, Gabriele; Rauch, Wolfgang; Deletic, Ana

2012-05-15

Urban drainage models are important tools used by both practitioners and scientists in the field of stormwater management. These models are often conceptual and usually require calibration using local datasets. The quantification of the uncertainty associated with the models is a must, although it is rarely practiced. The International Working Group on Data and Models, which works under the IWA/IAHR Joint Committee on Urban Drainage, has been working on the development of a framework for defining and assessing uncertainties in the field of urban drainage modelling. A part of that work is the assessment and comparison of different techniques generally used in the uncertainty assessment of the parameters of water models. This paper compares a number of these techniques: the Generalized Likelihood Uncertainty Estimation (GLUE), the Shuffled Complex Evolution Metropolis algorithm (SCEM-UA), an approach based on a multi-objective auto-calibration (a multialgorithm, genetically adaptive multi-objective method, AMALGAM) and a Bayesian approach based on a simplified Markov Chain Monte Carlo method (implemented in the software MICA). To allow a meaningful comparison among the different uncertainty techniques, common criteria have been set for the likelihood formulation, defining the number of simulations, and the measure of uncertainty bounds. Moreover, all the uncertainty techniques were implemented for the same case study, in which the same stormwater quantity and quality model was used alongside the same dataset. The comparison results for a well-posed rainfall/runoff model showed that the four methods provide similar probability distributions of model parameters, and model prediction intervals. For ill-posed water quality model the differences between the results were much wider; and the paper provides the specific advantages and disadvantages of each method. In relation to computational efficiency (i.e. number of iterations required to generate the probability distribution of parameters), it was found that SCEM-UA and AMALGAM produce results quicker than GLUE in terms of required number of simulations. However, GLUE requires the lowest modelling skills and is easy to implement. All non-Bayesian methods have problems with the way they accept behavioural parameter sets, e.g. GLUE, SCEM-UA and AMALGAM have subjective acceptance thresholds, while MICA has usually problem with its hypothesis on normality of residuals. It is concluded that modellers should select the method which is most suitable for the system they are modelling (e.g. complexity of the model's structure including the number of parameters), their skill/knowledge level, the available information, and the purpose of their study. Copyright © 2012 Elsevier Ltd. All rights reserved.

A conceptual model for the development of pristine drainage systems during exhumation of metamorphic core complexes

NASA Astrophysics Data System (ADS)

Trost, Georg; Neubauer, Franz; Robl, Jörg

2017-04-01

Metamorphic core complexes (MCCs) are defined as large scale geological features of domal shape. The essential characteristic comprises metamorphic rocks, which have been exhumed from lower crustal levels and now are exposed to the surface. The updoming process occurs at different tectonic settings of high strain zones initially exposing pristine gently dipping fault planes to Earth's surface. Consequently, the dome shape highly influences the type of adaption of the drainage systems to the active landforms. However, drainage systems and their characteristic metrics in regions shaped by MCCs have only been sparsely investigated and were not examined regarding the distinction between different MCC-types (A-type, B-type, C-type). In this study we investigate the drainage patterns of MCCs formed by different tectonic settings and build up a conceptual model for the development of the drainage systems under these conditions. We apply the χ-method to detect variations in uplift, as well as spatial unconformities in the drainage patterns. The χ-method is a mathematical approach to transform stream longitudinal profiles to the χ space where the slope of steady state profiles is solely dependent on uplift rate and bedrock erodibility. From this transformation we calculate color-coded χ-maps and χ-profiles of the main streams draining the MCCs. The applied method allows the interpretation of channel metrics in terms of (a) spatial gradients in uplift rate and (b) the time dependent evolution of drainage divides including drainage divide migration. Our results show a high variation in the shape and greatest elevation of the χ-profiles. This indicates the migration of active uplift zones along the dome axes. Even though only MCCs younger than Miocene age are investigated, the shape of the χ-profiles clearly points to different development stages of these areas. K-profiles plotted over the detachment underlying an active updoming process show concave shaped χ-profiles. In contrast, χ-profiles plotted over the detachments coined by long-term erosional processes tend to preserve prominent knickpoints in linearly proceeding profiles. Additionally, the migration of the watersheds indicates lateral extension of the domes, potentially influenced by rolling hinges. MCCs subjected to active uplift show proceeding stream piracy of streams following tectonically induced lineaments. Drainage systems have systematically deflected streams at the edges of the dome structures. The deflections can be especially observed at A-type domes (dome axis oriented parallel to the direction of extension). We conclude that our observations can be explained by the Rolling-Hinge model for MCC-formation. This model is applicable for all types of MCCs and gives the mechanical basis for the updoming process and such for the first stages of drainage development. Some of the observed features are dedicated to ongoing erosional processes and hence represent later phases of MCC development.

77 FR 29369 - Notice of Entering Into a Compact With the Republic of Zambia

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

... separate comprehensive urban development plan funded by Japanese International Cooperation Agency. All... conduct better maintenance and environmental management for the city's drainage network. Further, support..., representing less than four percent of the country's population. The city of Lusaka currently has a population...

Automated Passive Capillary Lysimeters for Estimating Water Drainage in the Vadose Zone

NASA Astrophysics Data System (ADS)

Jabro, J.; Evans, R.

2009-04-01

In this study, we demonstrated and evaluated the performance and accuracy of an automated PCAP lysimeters that we designed for in-situ continuous measuring and estimating of drainage water below the rootzone of a sugarbeet-potato-barley rotation under two irrigation frequencies. Twelve automated PCAPs with sampling surface dimensions of 31 cm width * 91 cm long and 87 cm in height were placed 90 cm below the soil surface in a Lihen sandy loam. Our state-of-the-art design incorporated Bluetooth wireless technology to enable an automated datalogger to transmit drainage water data simultaneously every 15 minutes to a remote host and had a greater efficiency than other types of lysimeters. It also offered a significantly larger coverage area (2700 cm2) than similarly designed vadose zone lysimeters. The cumulative manually extracted drainage water was compared with the cumulative volume of drainage water recorded by the datalogger from the tipping bucket using several statistical methods. Our results indicated that our automated PCAPs are accurate and provided convenient means for estimating water drainage in the vadose zone without the need for costly and manually time-consuming supportive systems.

Is peritoneal drainage essential after pancreatic surgery?

PubMed Central

Huan, Lu; Fei, Qilin; Lin, Huapeng; Wan, Lun; Li, Yue

2017-01-01

Abstract Aim: Our objective is to assess the function of peritoneal drainage, which is placed after pancreatic surgery. Background: With the medical advancement some study put forward that peritoneal drainage is not the necessary after pancreatic surgery; it cannot improve the complications of postoperation even leading to more infection and so on. However, there is no one study can clear and definite whether omitting the drainage after surgery or not. Method: Searching databases consist of all kinds of searching tools, such as Medline, The Cochrane Library, Embase, PubMed, etc. All the included studies should meet our demand of this meta-analysis. In the all interest outcomes blow we take the full advantage of RevMan5 to assess, the main measure is odds ratio (OR) with 95% confidence, the publication bias are assessed by Egger test and Begg test. Result: The rate of postoperative pancreatic fistula (POPF) in no drainage group is much lower than that in routine drainage group (OR = 0.47, I2 = 43%, P < .00001). The result of the 2 randomized controlled trials (RCTs) in this pool are almost accord with the former (OR = 0.57, I2 = 0%, P = .05). In subgroup the result suggest that the peritoneal drainage can increase the morbidity (OR = 0.71, I2 = 15%, P = .0002) after pancreaticoduodenectomy (PD), but reduce the mortality (OR = 1.92, I2 = 8%, P = .03) after PD. In distal pancreatectomy (DP) the rate of POPF and clinically relevant pancreatic fistula (CR-PF) is lower without drainage; there is no significant difference in the CR-PF, hospital stay, intra-abdominal abscess, radiologic invention, and the reoperation. Conclusion: In the current meta-analysis, we cannot make a clear conclusion whether to abandon the routine drainage or not, but from the subgroup we can see something is safer than nothing to routine peritoneal drainage. And the patients who underwent DP can attempt to omit the drainage. But it still needs more RCTs to assess the necessity of drainage. PMID:29390482

Successful late management of spontaneous esophageal rupture using T-tube mediastinoabdominal drainage.

PubMed

Ojima, H; Kuwano, H; Sasaki, S; Fujisawa, T; Ishibashi, Y

2001-08-01

Spontaneous esophageal rupture is extremely rare, and early symptoms of the disease are similar to those of emergency diseases of the chest and abdomen. The diagnosis and treatments are often delayed, resulting in an unfavorable outcome in some cases. We performed improved T-tube drainage for spontaneous esophageal rupture in 5 patients between 1995 and 1999. Our improved method was a modified procedure of the reported method of Abbott et al, as follows: a T-tube was inserted into the esophagus. A separate stab incision was made in the abdominal wall, and the long limb of the T-tube was brought out through this incision ensuring that the course of the T-tube intra-abdominally was short and straight, with some slack to allow for postoperative abdominal distension. An advantage of this method was that it facilitated healing of the fistula after removal of the T-tube. All patients were treated with a satisfactory outcome. This improved T-tube drainage was technically very easy and safe method for spontaneous esophageal rupture in severe cases.

Chronic Morel-Lavallée Lesion: A Novel Minimally Invasive Method of Treatment.

PubMed

Mettu, Ramireddy; Surath, Harsha Vardhan; Chayam, Hanumantha Rao; Surath, Amaranth

2016-11-01

A Morel-Lavallée lesion is a closed internal degloving injury resulting from a shearing force applied to the skin. The etiology of this condition may be motor vehicle accidents, falls, contact sports (ie, football, wrestling),1 and iatrogenic after mammoplasty or abdominal liposuction.2 Common sites of the lesions include the pelvis and/or thigh.3 Isolated Morel-Lavallée lesions without underlying fracture are likely to be missed, which result in chronicity. Management of this condition often requires extensive surgical procedures such as debridement, sclerotherapy, serial percutaneous drainage, negative pressure wound therapy (NPWT), and skin grafting.4,5 The authors wish to highlight a minimally invasive technique for the treatment of chronic Morel-Lavallée lesions.

MANAGEMENT OF PANCREATICOPLEURAL FISTULAS SECONDARY TO CHRONIC PANCREATITIS

PubMed Central

CAZZO, Everton; APODACA-RUEDA, Márcio; GESTIC, Martinho Antonio; CHAIM, Fábio Henrique Mendonça; de SAITO, Helena Paes de Almeida; UTRINI, Murillo Pimentel; CALLEJAS-NETO, Francisco; CHAIM, Elinton Adami

2017-01-01

ABSTRACT Introduction: Pancreaticopleural fistula is a rare complication of chronic pancreatitis. Objective: To describe pancreaticopleural fistula due to chronic pancreatitis and perform an extensive review of literature on this topic. Methods: Comprehensive narrative review through online research on the databases Medline and Lilacs for articles published over the last 20 years. There were 22 case reports and four case series selected. Results: The main indication for surgical treatment is the failure of clinical and/or endoscopic treatments. Surgery is based on internal pancreatic drainage, especially by means of pancreaticojejunostomy, and/or pancreatic resections. Conclusion: Pancreaticopleural fistula is a rare complication of chronic pancreatitis and the Frey procedure may be an appropriate therapeutic option in selected cases when clinical and endoscopic treatments are unsuccessful. PMID:29019567

Estimating flood hydrographs and volumes for Alabama streams

USGS Publications Warehouse

Olin, D.A.; Atkins, J.B.

1988-01-01

The hydraulic design of highway drainage structures involves an evaluation of the effect of the proposed highway structures on lives, property, and stream stability. Flood hydrographs and associated flood volumes are useful tools in evaluating these effects. For design purposes, the Alabama Highway Department needs information on flood hydrographs and volumes associated with flood peaks of specific recurrence intervals (design floods) at proposed or existing bridge crossings. This report will provide the engineer with a method to estimate flood hydrographs, volumes, and lagtimes for rural and urban streams in Alabama with drainage areas less than 500 sq mi. Existing computer programs and methods to estimate flood hydrographs and volumes for ungaged streams have been developed in Georgia. These computer programs and methods were applied to streams in Alabama. The report gives detailed instructions on how to estimate flood hydrographs for ungaged rural or urban streams in Alabama with drainage areas less than 500 sq mi, without significant in-channel storage or regulations. (USGS)

Assessing cellulolysis in passive treatment systems for mine drainage: a modified enzyme assay.

PubMed

McDonald, Corina M; Gould, W Douglas; Lindsay, Matthew B J; Blowes, David W; Ptacek, Carol J; Condon, Peter D

2013-01-01

A modified cellulase enzyme assay was developed to monitor organic matter degradation in passive treatment systems for mine drainage. This fluorogenic substrate method facilitates assessment of exo-(1,4)-β-D-glucanase, endo-(1,4)-β-D-glucanase, and β-glucosidase, which compose an important cellulase enzyme system. The modified method was developed and refined using samples of organic carbon-amended mine tailings from field experiments where sulfate reduction was induced as a strategy for managing water quality. Sample masses (3 g) and the number of replicates ( ≥ 3) were optimized. Matrix interferences within these metal-rich samples were found to be insignificant. Application of this modified cellulase assay method provided insight into the availability and degradation of organic carbon within the amended tailings. Results of this study indicate that cellulase enzyme assays can be applied to passive treatment systems for mine drainage, which commonly contain elevated concentrations of metals. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Comparison of performance of tile drainage routines in SWAT 2009 and 2012 in an extensively tile-drained watershed in the Midwest

NASA Astrophysics Data System (ADS)

Guo, Tian; Gitau, Margaret; Merwade, Venkatesh; Arnold, Jeffrey; Srinivasan, Raghavan; Hirschi, Michael; Engel, Bernard

2018-01-01

Subsurface tile drainage systems are widely used in agricultural watersheds in the Midwestern US and enable the Midwest area to become highly productive agricultural lands, but can also create environmental problems, for example nitrate-N contamination associated with drainage waters. The Soil and Water Assessment Tool (SWAT) has been used to model watersheds with tile drainage. SWAT2012 revisions 615 and 645 provide new tile drainage routines. However, few studies have used these revisions to study tile drainage impacts at both field and watershed scales. Moreover, SWAT2012 revision 645 improved the soil moisture based curve number calculation method, which has not been fully tested. This study used long-term (1991-2003) field site and river station data from the Little Vermilion River (LVR) watershed to evaluate performance of tile drainage routines in SWAT2009 revision 528 (the old routine) and SWAT2012 revisions 615 and 645 (the new routine). Both the old and new routines provided reasonable but unsatisfactory (NSE < 0.5) uncalibrated flow and nitrate loss results for a mildly sloped watershed with low runoff. The calibrated monthly tile flow, surface flow, nitrate-N in tile and surface flow, sediment and annual corn and soybean yield results from SWAT with the old and new tile drainage routines were compared with observed values. Generally, the new routine provided acceptable simulated tile flow (NSE = 0.48-0.65) and nitrate in tile flow (NSE = 0.48-0.68) for field sites with random pattern tile and constant tile spacing, while the old routine simulated tile flow and nitrate in tile flow results for the field site with constant tile spacing were unacceptable (NSE = 0.00-0.32 and -0.29-0.06, respectively). The new modified curve number calculation method in revision 645 (NSE = 0.50-0.81) better simulated surface runoff than revision 615 (NSE = -0.11-0.49). The calibration provided reasonable parameter sets for the old and new routines in the LVR watershed, and the validation results showed that the new routine has the potential to accurately simulate hydrologic processes in mildly sloped watersheds.

The effect of drainage tube on bleeding and prognosis after total knee arthroplasty: a prospective cohort study

PubMed Central

2014-01-01

Background To evaluate the effect of drainage tube on prognosis after total knee arthroplasty (TKA) and explore an effective treatment with favorable prognosis. Methods In a prospective study, 18 patients with TKA for the first time were included and randomly divided into three groups, group A (no placement of drainage tube), group B (negative pressure drainage), and group C (4 h clamping drainage). Intraoperative and postoperative blood loss, operation time, and the drainage volume were recorded and analyzed. Arthrocele, ecchymosis, and range of motion (ROM) were examined postoperatively. The degree of pain was scored by Visual Analog Scale (VAS) after 6, 12, and 24 h of operation. The complications were examined and HSS (hospital for special surgery) knee score was taken during the follow-up period. Results There was no significant difference in operation time, total blood loss, intraoperative blood loss, and VAS score among three groups. Meanwhile, the hidden blood loss in group B was significantly decreased compared with group A (P = 0.0015). The postoperative drainage volume of group B was significantly increased compared with group C (P = 0.0002). No drainage increased the rate of arthrocele and ecchymosis. Compared with group A, ROM after 3 days of operation in groups B and C was significantly increased (P = 0.0357, P = 0.0372, respectively). During follow-up study, no deep infection or deep venous thrombosis was found. Conclusion After TKA, early clamping of the drainage tube reduced the bleeding loss without adverse effect on prognosis, which might be useful for clinical application in future. PMID:24755244

In vivo lymph node mapping by Cadmium Tellurium quantum dots in rats.

PubMed

Si, Chengshuai; Zhang, Yunpeng; Lv, Xianbo; Yang, Wuli; Ran, Zhipeng; Sun, Peng

2014-12-01

Intraoperative lymph node mapping (LNM) is highly significant for many surgeries in patients with cancer. Many types of tracers are currently used, but the ideal method has not yet been identified. We aimed to identify a stable lymphatic drainage pathway in an animal model and compared the effects of quantum dots (QD), a new fluorescent tracer, with those of methylene blue in intraoperative LNM. Indian ink (0.2 mL) was subcutaneously injected into the plantar metatarsal regions of six Sprague-Dawley rats. After 2 wk of incubation and subsequent dissection, the potentially stained LNs were examined pathologically to identify the lymphatic drainage pathway. After applying anesthesia, 0.1 mL methylene blue (2%) and QD (1 mg/mL) were injected into the plantar metatarsal regions of six rats for intraoperative LNM. The QD group was observed with a near-infrared imaging system, and the methylene blue group was directly observed. Drainages were recorded at 5, 10, 30, 60, and 120 min and at 1 d. Two three-level drainage pathways, that is, a peripheral drainage (popliteal LNs, inguinal LNs, and axillary LNs) and a central drainage (popliteal lymph node [LN], iliac LN, and renal LN) pathways were identified. Both methylene blue and QD stained the sentinel lymph node (SLNs) quickly, but methylene blue was difficult to identify in the deep tissues and the LNs beyond the SLN. Furthermore, the blue-stained LNs remain dyed for only 2 h. In contrast, the QDs exhibited high target-to-background ratios in both the SLNs and the following LNs. Additionally, the fluorescence lasted from 5 min-1 d after injection. An ideal lymphatic drainage model was found. QDs are excellent tracers for intraoperative LNM compared with methylene blue. Near infrared fluorescent imaging is a promising LNM method for clinical practice. Copyright © 2014 Elsevier Inc. All rights reserved.

Computed statistics at streamgages, and methods for estimating low-flow frequency statistics and development of regional regression equations for estimating low-flow frequency statistics at ungaged locations in Missouri

USGS Publications Warehouse

Southard, Rodney E.

2013-01-01

The weather and precipitation patterns in Missouri vary considerably from year to year. In 2008, the statewide average rainfall was 57.34 inches and in 2012, the statewide average rainfall was 30.64 inches. This variability in precipitation and resulting streamflow in Missouri underlies the necessity for water managers and users to have reliable streamflow statistics and a means to compute select statistics at ungaged locations for a better understanding of water availability. Knowledge of surface-water availability is dependent on the streamflow data that have been collected and analyzed by the U.S. Geological Survey for more than 100 years at approximately 350 streamgages throughout Missouri. The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, computed streamflow statistics at streamgages through the 2010 water year, defined periods of drought and defined methods to estimate streamflow statistics at ungaged locations, and developed regional regression equations to compute selected streamflow statistics at ungaged locations. Streamflow statistics and flow durations were computed for 532 streamgages in Missouri and in neighboring States of Missouri. For streamgages with more than 10 years of record, Kendall’s tau was computed to evaluate for trends in streamflow data. If trends were detected, the variable length method was used to define the period of no trend. Water years were removed from the dataset from the beginning of the record for a streamgage until no trend was detected. Low-flow frequency statistics were then computed for the entire period of record and for the period of no trend if 10 or more years of record were available for each analysis. Three methods are presented for computing selected streamflow statistics at ungaged locations. The first method uses power curve equations developed for 28 selected streams in Missouri and neighboring States that have multiple streamgages on the same streams. Statistical estimates on one of these streams can be calculated at an ungaged location that has a drainage area that is between 40 percent of the drainage area of the farthest upstream streamgage and within 150 percent of the drainage area of the farthest downstream streamgage along the stream of interest. The second method may be used on any stream with a streamgage that has operated for 10 years or longer and for which anthropogenic effects have not changed the low-flow characteristics at the ungaged location since collection of the streamflow data. A ratio of drainage area of the stream at the ungaged location to the drainage area of the stream at the streamgage was computed to estimate the statistic at the ungaged location. The range of applicability is between 40- and 150-percent of the drainage area of the streamgage, and the ungaged location must be located on the same stream as the streamgage. The third method uses regional regression equations to estimate selected low-flow frequency statistics for unregulated streams in Missouri. This report presents regression equations to estimate frequency statistics for the 10-year recurrence interval and for the N-day durations of 1, 2, 3, 7, 10, 30, and 60 days. Basin and climatic characteristics were computed using geographic information system software and digital geospatial data. A total of 35 characteristics were computed for use in preliminary statewide and regional regression analyses based on existing digital geospatial data and previous studies. Spatial analyses for geographical bias in the predictive accuracy of the regional regression equations defined three low-flow regions with the State representing the three major physiographic provinces in Missouri. Region 1 includes the Central Lowlands, Region 2 includes the Ozark Plateaus, and Region 3 includes the Mississippi Alluvial Plain. A total of 207 streamgages were used in the regression analyses for the regional equations. Of the 207 U.S. Geological Survey streamgages, 77 were located in Region 1, 120 were located in Region 2, and 10 were located in Region 3. Streamgages located outside of Missouri were selected to extend the range of data used for the independent variables in the regression analyses. Streamgages included in the regression analyses had 10 or more years of record and were considered to be affected minimally by anthropogenic activities or trends. Regional regression analyses identified three characteristics as statistically significant for the development of regional equations. For Region 1, drainage area, longest flow path, and streamflow-variability index were statistically significant. The range in the standard error of estimate for Region 1 is 79.6 to 94.2 percent. For Region 2, drainage area and streamflow variability index were statistically significant, and the range in the standard error of estimate is 48.2 to 72.1 percent. For Region 3, drainage area and streamflow-variability index also were statistically significant with a range in the standard error of estimate of 48.1 to 96.2 percent. Limitations on the use of estimating low-flow frequency statistics at ungaged locations are dependent on the method used. The first method outlined for use in Missouri, power curve equations, were developed to estimate the selected statistics for ungaged locations on 28 selected streams with multiple streamgages located on the same stream. A second method uses a drainage-area ratio to compute statistics at an ungaged location using data from a single streamgage on the same stream with 10 or more years of record. Ungaged locations on these streams may use the ratio of the drainage area at an ungaged location to the drainage area at a streamgage location to scale the selected statistic value from the streamgage location to the ungaged location. This method can be used if the drainage area of the ungaged location is within 40 to 150 percent of the streamgage drainage area. The third method is the use of the regional regression equations. The limits for the use of these equations are based on the ranges of the characteristics used as independent variables and that streams must be affected minimally by anthropogenic activities.

Impedance Changes Indicate Proximal Ventriculoperitoneal Shunt Obstruction In Vitro.

PubMed

Basati, Sukhraaj; Tangen, Kevin; Hsu, Ying; Lin, Hanna; Frim, David; Linninger, Andreas

2015-12-01

Extracranial cerebrospinal fluid (CSF) shunt obstruction is one of the most important problems in hydrocephalus patient management. Despite ongoing research into better shunt design, robust and reliable detection of shunt malfunction remains elusive. The authors present a novel method of correlating degree of tissue ingrowth into ventricular CSF drainage catheters with internal electrical impedance. The impedance based sensor is able to continuously monitor shunt patency using intraluminal electrodes. Prototype obstruction sensors were fabricated for in-vitro analysis of cellular ingrowth into a shunt under static and dynamic flow conditions. Primary astrocyte cell lines and C6 glioma cells were allowed to proliferate up to 7 days within a shunt catheter and the impedance waveform was observed. During cell ingrowth a significant change in the peak-to-peak voltage signal as well as the root-mean-square voltage level was observed, allowing the impedance sensor to potentially anticipate shunt malfunction long before it affects fluid drainage. Finite element modeling was employed to demonstrate that the electrical signal used to monitor tissue ingrowth is contained inside the catheter lumen and does not endanger tissue surrounding the shunt. These results may herald the development of "next generation" shunt technology that allows prediction of malfunction before it affects patient outcome.

Management of haemothoraces in blunt thoracic trauma: study protocol for a randomised controlled trial

PubMed Central

Carver, David A; Bressan, Alexsander K; Schieman, Colin; Grondin, Sean C; Kirkpatrick, Andrew W; Lall, Rohan; McBeth, Paul B; Dunham, Michael B; Ball, Chad G

2018-01-01

Introduction Haemothorax following blunt thoracic trauma is a common source of morbidity and mortality. The optimal management of moderate to large haemothoraces has yet to be defined. Observational data have suggested that expectant management may be an appropriate strategy in stable patients. This study aims to compare the outcomes of patients with haemothoraces following blunt thoracic trauma treated with either chest drainage or expectant management. Methods and analysis This is a single-centre, dual-arm randomised controlled trial. Patients presenting with a moderate to large sized haemothorax following blunt thoracic trauma will be assessed for eligibility. Eligible patients will then undergo an informed consent process followed by randomisation to either (1) chest drainage (tube thoracostomy) or (2) expectant management. These groups will be compared for the rate of additional thoracic interventions, major thoracic complications, length of stay and mortality. Ethics and dissemination This study has been approved by the institution’s research ethics board and registered with ClinicalTrials.gov. All eligible participants will provide informed consent prior to randomisation. The results of this study may provide guidance in an area where there remains significant variation between clinicians. The results of this study will be published in peer-reviewed journals and presented at national and international conferences. Trial registration number NCT03050502. PMID:29502092

Perforated Duodenal Ulcer in High Risk Patients: Is Percutaneous Drainage Justified?

PubMed Central

Saber, Aly; Gad, Mohammad A; Ellabban, Gouda M

2012-01-01

Background: Conservative treatment was recommended as the treatment of choice in perforated acute peptic ulcer. Here, we adjunct percutaneous peritoneal drainage with nonoperative conservative treatment in high risk elderly patients with perforated duodenal ulcer. Aim: The work was to study the efficacy of percutaneous peritoneal drainage under local anesthesia supported by conservative measures in high risk elderly patients, according to the American Society of Anesthesiologists grading, with perforated duodenal ulcer. Patients and Methods: Twenty four high risk patients with age >65 years having associated medical illness with evidence of perforated duodenal ulcer. Results: The overall morbidity and mortality were comparable with those treated by conservative measures alone. Conclusion: In high risk patients with perforated peptic ulcer and established peritonitis, percutaneous peritoneal drainage under local anesthesia seems to be effective with least operative trauma and mortality rate. PMID:22393546

Single chest tube drainage is superior to double chest tube drainage after lobectomy: a meta-analysis.

PubMed

Zhou, Dong; Deng, Xu-Feng; Liu, Quan-Xing; Chen, Qian; Min, Jia-Xin; Dai, Ji-Gang

2016-05-27

In this meta-analysis, we conducted a pooled analysis of clinical studies comparing the efficacy of single chest tube versus double chest tube after a lobectomy. According to the recommendations of the Cochrane Collaboration, we established a rigorous study protocol. We performed a systematic electronic search of the PubMed, Embase, Cochrane Library and Web of Science databases to identify articles to include in our meta-analysis. A literature search was performed using relevant keywords. A meta-analysis was performed using RevMan© software. Five studies, published between 2003 and 2014, including 630 patients (314 patients with a single chest tube and 316 patients with a double chest tube), met the selection criteria. From the available data, the patients using a single tube demonstrated significantly decreased postoperative pain [weighted mean difference [WMD] -0.60; 95 % confidence intervals [CIs] -0.68-- 0.52; P < 0.00001], duration of drainage [WMD -0.70; 95 % CIs -0.90-- 0.49; P < 0.00001] and hospital stay [WMD -0.51; 95 % CIs -0.91-- 0.12; P = 0.01] compared to patients using a double tube after a pulmonary lobectomy. However, there were no significant differences in postoperative complications [OR 0.91; 95 % CIs 0.57-1.44; P = 0.67] and re-drainage rates [OR 0.81; 95 % CIs 0.42-1.58; P = 0.54]. Our results showed that a single-drain method is effective, reducing postoperative pain, hospitalization times and duration of drainage in patients who undergo a lobectomy. Moreover, the single-drain method does not increase the occurrence of postoperative complications and re-drainage rates.

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

PubMed Central

Zhou, Yu-Kun; Qin, Huan-Long; Zhang, Ming; Shen, Tong-Yi; Chen, Hong-Qi; Ma, Yan-Lei; Chu, Zhao-Xin; Zhang, Peng; Liu, Zhi-Hua

2012-01-01

AIM: To investigate the mechanisms of Lactobacillus plantarum (L. plantarum) action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats. METHODS: Forty rats were randomly divided into groups of sham-operation, bile duct ligation (BDL), BDL + L. plantarum, BDL + internal biliary drainage (IBD), and BDL + IBD + L. plantarum. Ten days after L. plantarum administration, blood and ileal samples were collected from the rats for morphological examination, and intestinal barrier function, liver function, intestinal oxidative stress and protein kinase C (PKC) activity measurement. The distribution and expression of the PKC and tight junction (TJ) proteins, such as occludin, zonula occludens-1, claudin-1, claudin-4, junction adhesion molecule-A and F-actin, were examined by confocal laser scanning microscopy, immunohistochemistry, Western blotting, real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: L. plantarum administration substantially restored gut barrier, decreased enterocyte apoptosis, improved intestinal oxidative stress, promoted the activity and expression of protein kinase (BDL vs BDL + L. plantarum, 0.295 ± 0.007 vs 0.349 ± 0.003, P < 0.05; BDL + IBD vs BDL + IBD + L. plantarum, 0.407 ± 0.046 vs 0.465 ± 0.135, P < 0.05), and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice (BDL vs BDL + L. plantarum, 0.266 ± 0.118 vs 0.326 ± 0.009, P < 0.05). The protective effect of L. plantarum was more prominent after internal biliary drainage ( BDL + IBD vs BDL + IBD + L. plantarum, 0.415 ± 0.105 vs 0.494 ± 0.145, P < 0.05). CONCLUSION: L. plantarum can decrease intestinal epithelial cell apoptosis, reduce oxidative stress, and prevent TJ disruption in biliary obstruction by activating the PKC pathway. PMID:22912548

Mortality Following Catheter Drainage Versus Thoracentesis in Cirrhotic Patients with Pleural Effusion.

PubMed

Hung, Tsung-Hsing; Tseng, Chih-Wei; Tsai, Chen-Chi; Hsieh, Yu-Hsi; Tseng, Kuo-Chih; Tsai, Chih-Chun

2017-04-01

Pleural effusion is an abnormal collection of body fluids that may cause related morbidity or mortality in cirrhotic patients. There are insufficient data to determine the optimal method of drainage, for symptomatic relief in cirrhotic patients with pleural effusion. In this study, we compare the mortality outcomes of catheter drainage versus thoracentesis in cirrhotic patients. The National Health Insurance Database, derived from the Taiwan National Health Insurance Program, was used to identify cirrhotic patients with pleural effusion requiring drainage between January 1, 2007, and December 31, 2010. In all, 2556 cirrhotic patients with pleural effusion were selected for the study and divided into the two groups (n = 1278/group) after propensity score matching. The mean age was 61.0 ± 14.3 years, and 68.9% (1761/2556) were men. The overall 30-day mortality was 21.0% (538/2556) and was higher in patients treated with catheter drainage than those treated with thoracentesis (23.5 vs. 18.6%, respectively, P < 0.001 by log-rank test). After Cox proportional hazard regression analysis adjusted by patient sex, age, and comorbid disorders, the risk of 30-day mortality was significantly higher in cirrhotic patients who accepted catheter drainage compared to thoracentesis (hazard ratio 1.30, 95% confidence interval 1.10-1.54, P = 0.003). Old age, hepatic encephalopathy, bleeding esophageal varices, hepatocellular carcinoma, ascites, and pneumonia were associated with higher risks for 30-day mortality. In cirrhotic patients with pleural effusion requiring drainage, catheter drainage is associated with higher mortality compared to thoracentesis.

Is the recurrence rate of chronic subdural hematomas dependent on the duration of drainage?

PubMed

Kale, Aydemir; Öz, İbrahim İlker; Gün, Eren Görkem; Kalaycı, Murat; Gül, Şanser

2017-05-01

Chronic subdural hematoma (CSDH) is the most frequent type of intracranial hemorrhage which especially affects the elderly. Various surgical techniques have been reported for CSDH treatment; optimal treatment methods are still controversial. In this study, the effects of long drainage durations on results and recurrences were investigated in patients on whom closed system drainage with burr hole craniotomy was applied due to CSDH. 90 patients with 105 CSDH were operated between 2008 and 2016. Patients were divided into two groups based on the duration of drainage. Group A (n = 40) was determined as 2-4 days of closed-system drainage, while Group B (n = 50) was recorded as 5-7 days of closed-system drainage. Recurrence was defined as accumulation of blood in the operation area and recurrence of symptoms within the monitoring period of six months. Recurrence was observed in 7 (15.6) of the Group A patients and 2 (3.3%) of the Group B patients. There was a statistically significant difference between groups in terms of recurrence rate (p = 0.04). Postoperative thickness of hematoma was measured in the first month follow-up computerized tomography. There was a statistically significant difference between groups in terms of postoperative thickness of residual hematoma (p = 0.05). 2-4 days of closed system drainage following burr hole craniotomy is an effective and reliable choice of treatment in CSDH. Nevertheless, increasing the duration of drainage to 5-7 days provided better results without increasing the risk of complication.

Evidence-based Value of Prophylactic Drainage in Gastrointestinal Surgery

PubMed Central

Petrowsky, Henrik; Demartines, Nicolas; Rousson, Valentin; Clavien, Pierre-Alain

2004-01-01

Objective: To determine the evidence-based value of prophylactic drainage in gastrointestinal (GI) surgery. Methods: An electronic search of the Medline database from 1966 to 2004 was performed to identify articles comparing prophylactic drainage with no drainage in GI surgery. The studies were reviewed and classified according to their quality of evidence using the grading system proposed by the Oxford Centre for Evidence-based Medicine. Seventeen randomized controlled trials (RCTs) were found for hepato-pancreatico-biliary surgery, none for upper GI tract, and 13 for lower GI tract surgery. If sufficient RCTs were identified, we performed a meta-analysis to characterize the drain effect using the random-effects model. Results: There is evidence of level 1a that drains do not reduce complications after hepatic, colonic, or rectal resection with primary anastomosis and appendectomy for any stage of appendicitis. Drains were even harmful after hepatic resection in chronic liver disease and appendectomy. In the absence of RCTs, there is a consensus (evidence level 5) about the necessity of prophylactic drainage after esophageal resection and total gastrectomy due to the potential fatal outcome in case of anastomotic and gastric leakage. Conclusion: Many GI operations can be performed safely without prophylactic drainage. Drains should be omitted after hepatic, colonic, or rectal resection with primary anastomosis and appendectomy for any stage of appendicitis (recommendation grade A), whereas prophylactic drainage remains indicated after esophageal resection and total gastrectomy (recommendation grade D). For many other GI procedures, especially involving the upper GI tract, there is a further demand for well-designed RCTs to clarify the value of prophylactic drainage. PMID:15570212

Determination of Flood Discharges in Rivers as a Prerequisite for Calculating Rates of Geomorphic Change in Drainage Basins During Extreme Events

NASA Astrophysics Data System (ADS)

Smith, J. D.; Kean, J. W.

2003-12-01

Accurate empirical determination of river discharge during an extreme event is very difficult even at a gage site. Moreover, the procurement of extreme flow measurements at many locations in an ungaged drainage basin often is necessary to relate the surface-water flow in the drainage network during a flood to the spatial distribution of intense rainfall. Consequently, paleo-hydrologic methods have to be employed to estimate peak discharges. These methods, however, require the application of some type of flow model. Often the flow models used with paleo-hydrologic data are over simplified and embody low-flow or extrapolated roughness coefficients that are inappropriate for the high flow of interest and that substantially reduce the reliability of the estimated discharge. Models that permit calculation of flow resistance from measured or calculated pre-flood, post-flood, or evolving channel and floodplain geometries and roughnesses can yield the most accurate results for these extreme situations. We have developed a procedure for directly calculating flow discharge as a function of stage in reaches a few tens of river widths in length. The foundation for this approach is a set of algorithms that permits computation of the form drag on topographic elements and woody vegetation. Its application requires an initial survey of the channel and floodplain topography and roughness. The method can be used either with stage determined from a set of pressure gages distributed throughout a drainage basin to monitor discharge in a drainage network or with paleo-hydrologic data to determine discharge from extreme events. Currently, our method of determining discharge from stage is being tested at various sites in the drainage basin of the Whitewater River, Kansas. Two of these sites are just downstream of USGS gages, and a third is a short distance downstream from the outlet pipe of a man-made lake. These tests are for a full range of hydrologic conditions in order to demonstrate that the model-based method for converting stage to discharge can be employed with confidence (1) in ungaged drainage basins where a large number of discharge measurements are required for hydrologic research, (2) at locations where rated USGS stage gages are too expensive, (3) near the sites of USGS stage gages for floods during which the discharge exceeds those for which the gage has been rated, and (4) for situations where paleo-flood methods have to be used to obtain a peak discharge. Model calculated rating curves are compared to measured ones for one of the USGS gage sites. Model calculations also are used to show that Manning's and other friction coefficients are functions of stage at this site. An approach such as the one described here is essential for the quantitative investigation of fluvial geomorphic processes caused by very large floods.

Headwater Capture Evidenced by Paleo-Rivers Reconstruction and Population Genetic Structure of the Armored Catfish (Pareiorhaphis garbei) in the Serra do Mar Mountains of Southeastern Brazil

PubMed Central

Lima, Sergio M. Q.; Berbel-Filho, Waldir M.; Araújo, Thais F. P.; Lazzarotto, Henrique; Tatarenkov, Andrey; Avise, John C.

2017-01-01

Paleo-drainage connections and headwater stream-captures are two main historical processes shaping the distribution of strictly freshwater fishes. Recently, bathymetric-based methods of paleo-drainage reconstruction have opened new possibilities to investigate how these processes have shaped the genetic structure of freshwater organisms. In this context, the present study used paleo-drainage reconstructions and single-locus cluster delimitation analyses to examine genetic structure on the whole distribution of Pareiorhaphis garbei, a ‘near threatened’ armored catfish from the Fluminense freshwater ecoregion in Southeastern Brazil. Sequences of two mitochondrial genes (cytochrome b and cytochrome c oxidase subunit 1) were obtained from five sampling sites in four coastal drainages: Macaé (KAE), São João (SJO), Guapi-Macacu [sub-basins Guapiaçu (GAC) and Guapimirim (GMI)], and Santo Aleixo (SAL). Pronounced genetic structure was found, involving 10 haplotypes for cytB and 6 for coi, with no haplotypes shared between localities. Coalescent-based delineation methods as well as distance-based methods revealed genetic clusters corresponding to each sample site. Paleo-drainage reconstructions showed two putative paleo-rivers: an eastern one connecting KAE and SJO; and a western one merging in the Guanabara Bay (GAC, GMI, and SAL). A disagreement was uncovered between the inferred past riverine connections and current population genetic structure. Although KAE and SJO belong to the same paleo-river, the latter is more closely related to specimens from the Guanabara paleo-river. This discordance between paleo-drainage connections and phylogenetic structure may indicate an ancient stream-capture event in headwaters of this region. Furthermore, all analyses showed high divergence between KAE and the other lineages, suggesting at least one cryptic species in the latter, and that the nominal species should be restricted to the Macaé river basin, its type locality. In this drainage, impacts such as the invasive species and habitat loss can be especially threatening for such species with a narrow range. Our results also suggest that freshwater fishes from headwaters in the Serra do Mar mountains might have different biogeographical patterns than those from the lowlands, indicating a complex and dynamic climatic and geomorphological history. PMID:29259623

Headwater Capture Evidenced by Paleo-Rivers Reconstruction and Population Genetic Structure of the Armored Catfish (Pareiorhaphis garbei) in the Serra do Mar Mountains of Southeastern Brazil.

PubMed

Lima, Sergio M Q; Berbel-Filho, Waldir M; Araújo, Thais F P; Lazzarotto, Henrique; Tatarenkov, Andrey; Avise, John C

2017-01-01

Paleo-drainage connections and headwater stream-captures are two main historical processes shaping the distribution of strictly freshwater fishes. Recently, bathymetric-based methods of paleo-drainage reconstruction have opened new possibilities to investigate how these processes have shaped the genetic structure of freshwater organisms. In this context, the present study used paleo-drainage reconstructions and single-locus cluster delimitation analyses to examine genetic structure on the whole distribution of Pareiorhaphis garbei , a 'near threatened' armored catfish from the Fluminense freshwater ecoregion in Southeastern Brazil. Sequences of two mitochondrial genes (cytochrome b and cytochrome c oxidase subunit 1) were obtained from five sampling sites in four coastal drainages: Macaé (KAE), São João (SJO), Guapi-Macacu [sub-basins Guapiaçu (GAC) and Guapimirim (GMI)], and Santo Aleixo (SAL). Pronounced genetic structure was found, involving 10 haplotypes for cytB and 6 for coi , with no haplotypes shared between localities. Coalescent-based delineation methods as well as distance-based methods revealed genetic clusters corresponding to each sample site. Paleo-drainage reconstructions showed two putative paleo-rivers: an eastern one connecting KAE and SJO; and a western one merging in the Guanabara Bay (GAC, GMI, and SAL). A disagreement was uncovered between the inferred past riverine connections and current population genetic structure. Although KAE and SJO belong to the same paleo-river, the latter is more closely related to specimens from the Guanabara paleo-river. This discordance between paleo-drainage connections and phylogenetic structure may indicate an ancient stream-capture event in headwaters of this region. Furthermore, all analyses showed high divergence between KAE and the other lineages, suggesting at least one cryptic species in the latter, and that the nominal species should be restricted to the Macaé river basin, its type locality. In this drainage, impacts such as the invasive species and habitat loss can be especially threatening for such species with a narrow range. Our results also suggest that freshwater fishes from headwaters in the Serra do Mar mountains might have different biogeographical patterns than those from the lowlands, indicating a complex and dynamic climatic and geomorphological history.

Bacterial contamination of tile drainage water and shallow groundwater under different application methods of liquid swine manure.

PubMed

Samarajeewa, A D; Glasauer, S M; Lauzon, J D; O'Halloran, I P; Parkin, Gary W; Dunfield, K E

2012-05-01

A 2 year field experiment evaluated liquid manure application methods on the movement of manure-borne pathogens (Salmonella sp.) and indicator bacteria (Escherichia coli and Clostridium perfringens) to subsurface water. A combination of application methods including surface application, pre-application tillage, and post-application incorporation were applied in a randomized complete block design on an instrumented field site in spring 2007 and 2008. Tile and shallow groundwater were sampled immediately after manure application and after rainfall events. Bacterial enumeration from water samples showed that the surface-applied manure resulted in the highest concentration of E. coli in tile drainage water. Pre-tillage significantly (p < 0.05) reduced the movement of manure-based E. coli and C. perfringens to tile water and to shallow groundwater within 3 days after manure application (DAM) in 2008 and within 10 DAM in 2007. Pre-tillage also decreased the occurrence of Salmonella sp. in tile water samples. Indicator bacteria and pathogens reached nondetectable levels within 50 DAM. The results suggest that tillage before application of liquid swine manure can minimize the movement of bacteria to tile and groundwater, but is effective only for the drainage events immediately after manure application or initial rainfall-associated drainage flows. Furthermore, the study highlights the strong association between bacterial concentrations in subsurface waters and rainfall timing and volume after manure application.

Thin film drainage between pre-inflated capsules or vesicles

NASA Astrophysics Data System (ADS)

Keh, Martin; Walter, Johann; Leal, Gary

2013-11-01

Capsules and vesicles are often used as vehicles to carry active ingredients or fragrance in drug delivery and consumer products and oftentimes in these applications the particles may be pre-inflated due to the existence of a small osmotic pressure difference between the interior and exterior fluid. We study the dynamics of thin film drainage between capsules and vesicles in flow as it is crucial to fusion and deposition of the particles and, therefore, the stability and effectiveness of the products. Simulations are conducted using a numerical model coupling the boundary integral method for the motion of the fluids and a finite element method for the membrane mechanics. For low capillary numbers, the drainage behavior of vesicles and capsules are approximately the same, and also similar to that of drops as the flow-independent and uniform tension due to pre-inflation dominates. The tension due to deformation caused by flow will become more important as the strength of the external flow (i.e. the capillary number) increases. In this case, the shapes of the thin film region are fundamentally different for capsules and vesicles, and the drainage behavior in both cases differs from a drop. Funded by P&G.

Chest drainage teaching and training for medical students. Use of a surgical ex vivo pig model.

PubMed

Tube, Milton Ignacio Carvalho; Netto, Fernando Antonio Campelo Spencer; Costa, Elaine; Lafayette, Daniell de Siqueira Araújo; Lima, George Augusto da Fonseca Carvalho Antunes; Menezes, Jamile Isabela Santos de; Aires, Vinicius Gueiros Buenos; Ferraz, Álvaro Antônio Bandeira; Campos, Josemberg Marins; Moraes, Fernando Ribeiro de

2016-05-01

Implement a constructivist approach in thoracic drainage training in surgical ex vivo pig models, to compare the acquisition of homogeneous surgical skills between medical students. Experimental study, prospective, transversal, analytical, controlled, three steps. Selection, training, evaluation. a) students without training in thoracic drainage; b) without exposure to constructivist methodology. 2) EXCLUSION CRITERIA: a) students developed surgical skills; b) a history of allergy. (N = 312). Two groups participated in the study: A and B. Lecture equal for both groups. Differentiated teaching: group A, descriptive and informative method; group B, learning method based on problems. A surgical ex vivo pig model for training the chest drain was created. Were applied pre and post-test, test goal-discursive and OSATS scale. Theoretical averages: Group A = 9.5 ± 0.5; Group B = 8.8 ± 1.1 (p = 0.006). Medium Practices: Group A = 22.8 ± 1.8; Group B = 23.0 ± 2.8 (p <0.001). Through the constructivist methodology implemented in the thoracic drainage training in surgical ex vivo pig models, has proven the acquisition of surgical skills homogeneous compared among medical students.

Assessment of the use of latissimus dorsi restoration during modified radical mastectomy in breast cancer patients.

PubMed

Yang, Chao; Wang, Xinle; Zhang, Geng; Yang, Liu; Guo, Xuan; Wang, Xue; Song, Zhenchuan

2017-12-01

The incision area of modified radical mastectomy in breast cancer patients is associated with subcutaneous effusion and skin flap necrosis as the most common complications. The aim of the present study was to assess the effect of latissimus dorsi restoration during modified radical mastectomy in breast cancer patients by evaluating 365 cases. Among these cases, 185 received modified radical mastectomy combined with intraoperative latissimus dorsi restoration, while 180 received modified radical mastectomy alone. The flap tension, drainage fluid amount and extubation time were compared between the two methods. The flap tension in patients who received modified radical mastectomy combined with intraoperative latissimus dorsi restoration was significantly lower and the blood supply was better. After surgery, the drainage fluid amount was also significantly lower in these patients compared with the control group. Furthermore, the mean time to drainage tube removal was significantly shorter in these patients and the postoperative cosmetic outcome was superior. Thus, it was concluded that modified radical mastectomy combined with intraoperative latissimus dorsi restoration in breast cancer patients was associated with reduced drainage fluid effusion, shorter hospitalization time and decreased flap tension. Overall, this method appears to be potentially suitable for extensive application in the clinical setting.

Analysis of Ancient Fluvial Patterns on the Surface of Mars

NASA Technical Reports Server (NTRS)

Jethani, Henna; Williams, M. E.

2010-01-01

This project involves the study of ancient fluvial patterns on the surface of Mars, including raised curvilinear features (RCFs) and negative relief channels. It requires the use of geological images provided by the Mars Reconnaissance Orbiter to determine how water shaped the surface of Mars in the form of rivers, lakes and/or oceans approximately 3.5 billion years ago, during the Noachian period. The role of the intern is to examine the images and record the corresponding measurements of ancient river systems in an Excel spreadsheet to assist in determining the Noachian water cycle on Mars. Resources used to make these measurements include the Arena software, hand-drawn sketch maps, Microsoft Word, Microsoft Excel and the images provided by the Mars Reconnaissance Orbiter. The Context Imager (CTX) returns black and white images at a resolution of six meters per pixel. The camera can take images with a width of 30 km and a length of 160 km. Seventeen images were observed in total. Images are analyzed and notes are taken concerning their terminal deposits, stream ordering and drainage pattern. The Arena software is utilized to make the images more visible by allowing control of contrast and magnification. Once the image is adjusted, measurements: length, average width, drainage basin area, sinuous ridge area are recorded, at a magnification of one, through using the line segment and polygon tools. After an image has been analyzed and measured, a sketch map is drawn in order to clearly identify the various segments, basins and terminal deposits the intern observed. Observations are used to further classify the fluvial patterns; their drainage pattern is defined as dendritic, parallel, trellis, rectangular, radial, centripetal, deranged or discordant. Once observational notes are completed, mathematical relations are used to determine drainage density, stream frequency, theoretic basin area and sinuosity index. These data will be added to a larger data set that will yield a comprehensive view of early Mars drainage systems. The data obtained from the work conducted will be used to characterize the nature and behavior of water on the surface of Mars. Thorough understanding of the Martian water cycle will serve as biologically significant information. Through working on this project, I acquired insight into the study of planet Mars, and skills in the Arena software as well as the organization of a vast amount of data.

Phase II modification of the Water Availability Tool for Environmental Resources (WATER) for Kentucky: The sinkhole-drainage process, point-and-click basin delineation, and results of karst test-basin simulations

USGS Publications Warehouse

Taylor, Charles J.; Williamson, Tanja N.; Newson, Jeremy K.; Ulery, Randy L.; Nelson, Hugh L.; Cinotto, Peter J.

2012-01-01

This report describes Phase II modifications made to the Water Availability Tool for Environmental Resources (WATER), which applies the process-based TOPMODEL approach to simulate or predict stream discharge in surface basins in the Commonwealth of Kentucky. The previous (Phase I) version of WATER did not provide a means of identifying sinkhole catchments or accounting for the effects of karst (internal) drainage in a TOPMODEL-simulated basin. In the Phase II version of WATER, sinkhole catchments are automatically identified and delineated as internally drained subbasins, and a modified TOPMODEL approach (called the sinkhole drainage process, or SDP-TOPMODEL) is applied that calculates mean daily discharges for the basin based on summed area-weighted contributions from sinkhole drain-age (SD) areas and non-karstic topographically drained (TD) areas. Results obtained using the SDP-TOPMODEL approach were evaluated for 12 karst test basins located in each of the major karst terrains in Kentucky. Visual comparison of simulated hydrographs and flow-duration curves, along with statistical measures applied to the simulated discharge data (bias, correlation, root mean square error, and Nash-Sutcliffe efficiency coefficients), indicate that the SDPOPMODEL approach provides acceptably accurate estimates of discharge for most flow conditions and typically provides more accurate simulation of stream discharge in karstic basins compared to the standard TOPMODEL approach. Additional programming modifications made to the Phase II version of WATER included implementation of a point-and-click graphical user interface (GUI), which fully automates the delineation of simulation-basin boundaries and improves the speed of input-data processing. The Phase II version of WATER enables the user to select a pour point anywhere on a stream reach of interest, and the program will automatically delineate all upstream areas that contribute drainage to that point. This capability enables automatic delineation of a simulation basin of any size (area) and having any level of stream-network complexity. WATER then automatically identifies the presence of sinkholes catchments within the simulation basin boundaries; extracts and compiles the necessary climatic, topographic, and basin characteristics datasets; and runs the SDP-TOPMODEL approach to estimate daily mean discharges (streamflow).

Physiochemical, site, and bidirectional reflectance factor characteristics of uniformly moist soils. [Brazil, Spain and the United States of America

NASA Technical Reports Server (NTRS)

Stoner, E. R.; Baumgardner, M. F. (Principal Investigator)

1980-01-01

The author has identified the following significant results. The bidirectional reflectance factor (0.5 micron to 2.3 micron wavelength interval) and physiochemical properties of over 500 soils from 39 states, Brazil and Spain were measured. Site characteristics of soil temperature regime and moisture zone were used as selection criteria. Parent material and internal drainage were noted for each soil. At least five general types of soil reflectance curves were identified based primarily on the presence or absence of ferric iron absorption bands, organic matter content, and soil drainage characteristics. Reflectance in 10 bands across the spectrum was found to be negatively correlated with the natural log of organic matter content.

Sensitivity of drainage efficiency of cranberry fields to edaphic conditions

NASA Astrophysics Data System (ADS)

Periard, Yann; José Gumiere, Silvio; Rousseau, Alain N.; Caron, Jean; Hallema, Dennis W.

2014-05-01

Water management on a cranberry farm requires intelligent irrigation and drainage strategies to sustain strong productivity and minimize environmental impact. For example, to avoid propagation of disease and meet evapotranspiration demand, it is imperative to maintain optimal moisture conditions in the root zone, which depends on an efficient drainage system. However, several drainage problems have been identified in cranberry fields. Most of these drainage problems are due to the presence of a restrictive layer in the soil profile (Gumiere et al., 2014). The objective of this work is to evaluate the effects of a restrictive layer on the drainage efficiency by the bias of a multi-local sensitivity analysis. We have tested the sensitivity of the drainage efficiency to different input parameters set of soil hydraulic properties, geometrical parameters and climatic conditions. Soil water flux dynamic for every input parameters set was simulated with finite element model Hydrus 1D (Simanek et al., 2008). Multi-local sensitivity was calculated with the Gâteaux directional derivatives with the procedure described by Cheviron et al. (2010). Results indicate that drainage efficiency is more sensitive to soil hydraulic properties than geometrical parameters and climatic conditions. Then, the geometrical parameters of the depth are more sensitive than the thickness. The drainage efficiency was very insensitive to the climatic conditions. Understanding the sensitivity of drainage efficiency according to soil hydraulic properties, geometrical and climatic conditions are essential for diagnosis drainage problems. However, it becomes important to identify the mechanisms involved in the genesis of anthropogenic soils cranberry to identify conditions that may lead to the formation of a restrictive layer. References: Cheviron, B., S.J. Gumiere, Y. Le Bissonnais, R. Moussa and D. Raclot. 2010. Sensitivity analysis of distributed erosion models: Framework. Water Resources Research 46: W08508. doi:10.1029/2009WR007950. Gumiere, S.J., J. Lafond, D. W. Hallema, Y. Périard, J. Caron et J. Gallichand. 2014. Mapping soil hydraulic conductivity and matric potential for water management of cranberry: Characterization and spatial interpolation methods. Biosystems Engineering.

Systems and methods for producing hydrocarbons from tar sands formations

DOEpatents

Li, Ruijian [Katy, TX; Karanikas, John Michael [Houston, TX

2009-07-21

A system for treating a tar sands formation is disclosed. A plurality of heaters are located in the formation. The heaters include at least partially horizontal heating sections at least partially in a hydrocarbon layer of the formation. The heating sections are at least partially arranged in a pattern in the hydrocarbon layer. The heaters are configured to provide heat to the hydrocarbon layer. The provided heat creates a plurality of drainage paths for mobilized fluids. At least two of the drainage paths converge. A production well is located to collect and produce mobilized fluids from at least one of the converged drainage paths in the hydrocarbon layer.

Variety, State and Origin of Drained Thaw Lake Basins in West-Siberian North

NASA Astrophysics Data System (ADS)

Kirpotin, S.; Polishchuk, Y.; Bryksina, N.; Sugaipova, A.; Pokrovsky, O.; Shirokova, L.; Kouraev, A.; Zakharova, E.; Kolmakova, M.; Dupre, B.

2009-04-01

Drained thaw lake basins in Western Siberia have a local name "khasyreis" [1]. Khasyreis as well as lakes, ponds and frozen mounds are invariable element of sub-arctic frozen peat bogs - palsas and tundra landscapes. In some areas of West-Siberian sub-arctic khasyreis occupy up to 40-50% of total lake area. Sometimes their concentration is so high that we call such places ‘khasyrei's fields". Khasyreis are part of the natural cycle of palsa complex development [1], but their origin is not continuous and uniform in time and, according to our opinion, there were periods of more intensive lake drainage and khasyrei development accordingly. These times were corresponding with epochs of climatic warming and today we have faced with one of them. So, last years this process was sufficiently activated in the south part of West-Siberian sub-arctic [2]. It was discovered that in the zone of continuous permafrost thermokarst lakes have expanded their areas by about 10-12%, but in the zone of discontinuous permafrost the process of their drainage prevails. These features are connected with the thickness of peat layers which gradually decreases to the North, and thus have reduced the opportunity for lake drainage in northern areas. The most typical way of khasyrei origin is their drainage to the bigger lakes which are always situated on the lower levels and works as a collecting funnels providing drainage of smaller lakes. The lower level of the big lake appeared when the lake takes a critical mass of water enough for subsidence of the lake bottom due to the melting of underlaying rocks [2]. Another one way of lake drainage is the lake intercept by any river. Lake drainage to the subsurface (underlaying rocks) as some authors think [3, 4] is not possible in Western Siberia, because the thickness of permafrost is at list 500 m here being safe confining bed. We mark out few stages of khasyrei development: freshly drained, young, mature and old. This row reflects stages of repeated permafrost heaving from small declustered frozen mounds to recovery of palsa plateaus due to growing and merging of isolated mounds. It was shown that satellite altimetry, which was applied for the first time in permafrost zone in the framework of Russian-French project CAR-WET-SIB, is a prospective method to study lakes and khasyreis state and dynamic. References [1] Kirpotin S.N., Naumov A .V., Vorobiov S.N., Mironycheva-Tokareva N.P., Kosych N.P., Lapshina E.D., Marquand J., Kulizhski S.P., Bleuten W. 2007. Western-Siberian Peatlands: Indicators of Climate Change and Their Role in Global Carbon Balance. Chapter 33 in Climate Change and Terrestrial Carbon Sequestration in Central Asia / edited by R.Lal, M.Suleimenov, B.A.Stewart, D.O.Hansen, and P.Doraiswamy, Taylor and Francis, Amsterdam, Holland, pp. 453-472. [2] Kirpotin S., Polishchuk Yu., Zakharova E., Shirokova L., Pokrovsky O., Kolmakova M., Dupre B. 2008. One of Possible Mechanisms of Thermokarst Lakes Drainage in West-Siberian North // International Journal of Environmental Studies. Vol.65, No 5, October 2008, 631-635. [3] Smith, L.C., Sheng, Y., McDonald, G.M., Hinzman, L.D. 2005. Disappearing Arctic Lakes, Science, 308, 1429 [4] Hinkel, K.M., Eisner, W.R., Bockheim, J.G., Nelson, F.E., Peterson, K.M., and Dai, X. 2003. Spatial Extent, Age, and Carbon Stoks in Drained Thaw Lake Basins on the Barrow Peninsula. Alaska. Arctic, Antarctic, and Alpine Research, 35, 3, 291-300.

The Use of TissuGlu® Surgical Adhesive for Mastectomy With or Without Lymphonodectomy.

PubMed

Ohlinger, Ralf; Gieron, Leonie; Rutkowski, Rico; Kohlmann, Thomas; Zygmunt, Marek; Unger, Julia

2018-01-01

Using drains after breast surgery is a preventive, but invasive measure to reduce seroma formation. A polyurethane-based tissue adhesive (TissuGlu®) might facilitate drainage-free wound healing after mastectomy in a non-invasive manner. Retrospectively, data from 84 patients (42 receiving TissuGlu®, 42 receiving a drainage) who underwent mastectomy, were collected (90 days postoperative follow-up). Study endpoints were defined as the number of fluid-related postoperative clinical interventions, cumulative volume of postoperative wound fluid, duration of hospitalization and postoperative complications. In the entirety of postoperative interventions, no significant difference could be demonstrated (p=0.298). The drainage arm showed significantly less seroma aspirations (p=0.024) and complications (p=0.012). A significantly reduced length of hospitalization (p<0.001) and less cumulative wound secretion volume (p<0.001) appeared in the TissuGlu® group. The polyurethane-based tissue adhesive is a less invasive alternative to drain use in mastectomy. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

A New CT-Guided Modified Trocar Technique for Drainage of Difficult Locations Abscesses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyng, Chiang J., E-mail: chiangjengtyng@gmail.com; Amoedo, Maurício K.; Bohrer, Yves

PurposeComputed tomography (CT) is commonly used to guide drainage of deep-seated abdominal fluid collections. However, in some cases, these collections seem to be inaccessible due to surrounding organs or their being in difficult locations. The aim of this study is to describe a modified Trocar technique to drain collections in difficult locations, especially those in the subphrenic space, without passing through intervening organs.Materials and MethodsThis retrospective case series study describes seven inpatients who underwent CT-guided drainage using a modified Trocar technique for abscesses that are difficult to access percutaneously. All patients provided written informed consent prior to the procedure. Aftermore » placement of a 12–14F catheter inside the peritoneum, the Trocar stylet was removed so that the tip of the catheter became blunt and flexible to avoid injury to organs and structures in the catheter route, and the catheter was slowly advanced towards the collection using CT guidance and tactile sensation. After reaching the target, the stylet was reintroduced to enter the abscess wall.ResultsAll procedures were performed using an anterior abdominal wall access with adequate catheter positioning and resulted in clinical status improvement in the days after the drainage. No complications related to the procedure were identified in any of the patients.ConclusionsThe modified Trocar technique for percutaneous CT-guided drainage of abdominal abscesses may be feasible for lesions that are difficult to access with conventional methods.« less

Sternotomy or drainage for a hemopericardium after penetrating trauma: a randomized controlled trial.

PubMed

Nicol, Andrew J; Navsaria, Pradeep H; Hommes, Martijn; Ball, Chad G; Edu, Sorin; Kahn, Delawir

2014-03-01

To determine if stable patients with a hemopericardium detected after penetrating chest trauma can be safely managed with pericardial drainage alone. The current international practice is to perform a sternotomy and cardiac repair if a hemopericardium is detected after penetrating chest trauma. The experience in Cape Town, South Africa, on performing a mandatory sternotomy in hemodynamically stable patients was that a sternotomy was unnecessary and the cardiac injury, if present, had sealed. A single-center parallel-group randomized controlled study was completed. All hemodynamically stable patients with a hemopericardium confirmed at subxiphoid pericardial window (SPW), and no active bleeding, were randomized. The primary outcome measure was survival to discharge from hospital. Secondary outcomes were complications and postoperative hospital stay. Fifty-five patients were randomized to sternotomy and 56 to pericardial drainage and wash-out only. Fifty-one of the 55 patients (93%) randomized to sternotomy had either no cardiac injury or a tangential injury. There were only 4 patients with penetrating wounds to the endocardium and all had sealed. There was 1 death postoperatively among the 111 patients (0.9%) and this was in the sternotomy group. The mean intensive care unit (ICU) stay for a sternotomy was 2.04 days (range, 0-25 days) compared with 0.25 days (range, 0-2) for the drainage (P < 0.001). The estimated mean difference highlighted a stay of 1.8 days shorter in the ICU for the drainage group (95% CI: 0.8-2.7). Total hospital stay was significantly shorter in the SPW group (P < 0.001; 95% CI: 1.4-3.3). SPW and drainage is effective and safe in the stable patient with a hemopericardium after penetrating chest trauma, with no increase in mortality and a shorter ICU and hospital stay. (ClinicalTrials.gov Identifier: NCT00823160).

Collagen sealant patch to reduce lymphatic drainage after lymph node dissection

PubMed Central

2012-01-01

Background Seroma formation is a frequent complication following radical lymph node dissection (RLND) in patients with metastatic melanoma. Several strategies have been used to prevent fluid accumulation and thereby reduce the duration of postoperative drainage, including fibrin sealants. Methods This was a prospective, single-center study in which consecutive patients undergoing surgical treatment of stage III metastatic melanoma by axillary or ilio-inguinal RLND were randomized to receive standard treatment plus fibrinogen/thrombin-coated collagen sealant patch (CSP) or standard treatment alone. The primary endpoint of the study was postoperative duration of drainage. Results A total of 70 patients underwent axillary (n = 47) or ilio-inguinal (n = 23) RLND and received CSP plus standard treatment (n = 37) or standard treatment alone (n = 33). Mean duration of drainage was significantly reduced in the CSP group compared with standard treatment (ITT analysis: 20.1 ± 5.1 versus 23.3 ± 5.1 days; p = 0.010). The percentage of patients drainage-free on day 21 was significantly higher in the CSP group compared with the standard treatment group (86% versus 67%; p = 0.049). Conclusions Use of the tissue sealant resulted in a significant reduction in duration of drainage. Further studies are warranted to confirm these results in different and selected types of lymphadenectomy. PMID:23253298

Automated intracranial pressure-controlled cerebrospinal fluid external drainage with LiquoGuard.

PubMed

Linsler, Stefan; Schmidtke, Mareike; Steudel, Wolf Ingo; Kiefer, Michael; Oertel, Joachim

2013-08-01

LiquoGuard is a new device for intracranial pressure (ICP)-controlled drainage of cerebrospinal fluid (CSF). This present study evaluates the accuracy of ICP measurement via the LiquoGuard device in comparison with Spiegelberg. Thus, we compared data ascertained from simultaneous measurement of ICP using tip-transducer and tip-sensor devices. A total of 1,764 monitoring hours in 15 patients (range, 52-219 h) were analysed. All patients received an intraventricular Spiegelberg III probe with the drainage catheter connected to the LiquoGuard system. ICP reading of both devices was performed on an hourly basis. Statistical analysis was done by applying Pearson correlation and Wilcoxon-matched pair test (p < 0.05). Mean ICP values were 11 ± 5 mmHg (Spiegelberg) and 10 ± 7 mmHg (LiquoGuard); the values measured with both devices correlated well (p = 0.001; Pearson correlation =0.349; n = 1,764). In two of the 15 patients with slit ventricles, episodes of significant differences in measured values could be observed. Both patients suffering from slit ventricles failed to produce reliable measurement with the external transducer of the LiquoGuard. LiquoGuard is a valuable new device for ICP-controlled CSF drainage. However, LiquoGuard tends to provide misleading results in slit ventricles. Thus, before these drawbacks are further analysed, the authors recommend additional ICP measurement with internal tip-sensor devices to avoid dangerous erroneous interpretation of ICP data.

Characterization of the hydraulic performance of a gully under drainage conditions.

PubMed

Martins, Ricardo; Leandro, Jorge; de Carvalho, Rita Fernandes

2014-01-01

During rainfall events with low return periods (1-20 years) the drainage system can provide some degree of protection to urban areas. The system design is based not only on good hydraulic performance of the surface and the sewer network but also on their linking elements. Although the linking elements are of utmost importance as they allow the exchange of flow between the surface and the sewer network, there is a lack of studies that thoroughly characterize them. One crucial structural part of those elements is the gully. State-of-the-art dual-drainage models often use simplified formulae to replicate the gully hydraulic behaviour that lacks proper validation. This work focuses on simulating, both numerically and experimentally, the hydraulic performance of a 0.6 × 0.3 × 0.3 [m] (L × W × D) gully located inside an 8 × 0.5 × 0.5 [m] rectangular channel. The numerical simulations are conducted with the OpenFOAM toolbox and validated with water level measurements in the Multiple-Linking-Element experimental installation located at the Laboratory of Hydraulics of the University of Coimbra. The results provide a complete three-dimensional insight of the hydraulic behaviour of the flow inside the gully, and discharge coefficient formulae are disclosed that can be directly applied in dual-drainage models as internal boundary conditions.

[Emergency Surgery and Treatments for Pneumothorax].

PubMed

Kurihara, Masatoshi

2015-07-01

The primary care in terms of emergency for pneumothorax is chest drainage in almost cases. The following cases of pneumothorax and the complications need something of surgery and treatments. Pneumothorax with subcutaneous emphysema often needs small skin incisions around the drainage tube. Tension pneumothorax often needs urgent chest drainage. Pneumothorax with intractable air leakage often needs interventional treatments like endobroncheal occlusion (EBO) or thoracographic fibrin glue sealing method (TGF) as well as urgent thoracoscopic surgery. Pneumothorax with acute empyema also often needs urgent thoracoscopic surgery within 2 weeks if chest drainage or drug therapy are unsuccessful. It will probably become chronic empyema of thorax after then. Pneumothorax with bleeding needs urgent thoracoscopic surgery in case of continuous bleeding over 200 ml/2 hours. In any cases of emergency for pneumothorax, respiratory physicians should collaborate with respiratory surgeons at the 1st stage because it is important to timely judge conversion of surgical treatments from medical treatments.

Advances in urban-drainage management and flood protection.

PubMed

Verworn, Hans-Reinhard

2002-07-15

Since the beginning of modern urban drainage in the 19th century, the sole objective has been to get rid of sewage and storm water in the best possible way and design the systems according to accepted standards. In recent decades, advanced methods have been developed not only to refine the design but also especially to enable the assessment of hydraulic performance and pollutant emissions. Consequently, urban drainage has become part of an integrated approach concerning flood protection as well as ecological aspects for whole watersheds. Another major change concerns the management of urban systems: simple structural maintenance has been replaced by interactive operational management and control of the systems in order to make better use of the facilities. Rehabilitation has become a multi-objective task. This paper looks at today's basic principles of urban drainage and tomorrow's potential advances, and deals with their relevance to flood protection.

Simulating the arrangement of subsystem to reduce inundation in the drainage system of Pepelegi housing area Sidoarjo

NASA Astrophysics Data System (ADS)

Brouwer, Steven; Wardoyo, Wasis; Lasminto, Umboro

2017-06-01

Pepelegi Indah Resident is a place which is frequently inundated by floodwater. This condition happened since the drainage system was designed with inappropriate waterflow method. The concern of this research was to figure out alternatives by managing the floodwater from the disposal drainage system. The existing information showed the area would be inundated if rainfall occurred for 2-3 hours. Half of Pepelegi Indah Resident would be inundated and subsidence time of flood on vulnerable time was 5-24 hours. To reduce the floodwater, some scenarios or simulations were carried out among others the management of tertiary drainage, the pool accommodation, and the provision of pumps at the enable point. From the simulation, the researcher should choose the best scenario which worked and optimally reduce the flooding. Based on the simulation results, the best scenario is the pool accommodation with new pumps at the primary channel.

Five years of beach drainage survey on a macrotidal beach (Quend-Plage, northern France)

NASA Astrophysics Data System (ADS)

Bain, Olivier; Toulec, Renaud; Combaud, Anne; Villemagne, Guillaume; Barrier, Pascal

2016-07-01

A drainage system was installed in 2008 on the macrotidal beach of Quend-Plage, close to Abbeville (Somme, northern France), following a period of significant erosion of recreational areas. The "Direction départementale des territoires et de la mer" (French Coastal Department Authority) has requested a biannual survey in order to validate the beach drainage setup and its efficiency. This paper presents the methodology used for this survey, and the response of the coastal system to this soft engineering method for preventing erosion. These five years of drainage operation have strongly modified the morphology of the beach. Three main modifications occurred: (i) accretion of the upper beach and foredune, (ii) erosion of the lower and middle beach and (iii) a slight shift in directions of the beach bars and troughs. These morphological changes finally led to the stabilization of the beach.

An experience with video-assisted anal fistula treatment (VAAFT) with new insights into the treatment of anal fistulae.

PubMed

Seow-En, I; Seow-Choen, F; Koh, P K

2016-06-01

The aim of this retrospective study was to assess our experience of 41 patients with anal fistulae treated with video-assisted anal fistula treatment (VAAFT). Forty-one consecutive patients with cryptoglandular anal fistulae were included. Patients with low intersphincteric anal fistulae or those with gross perineal abscess were excluded. Eleven (27 %) patients had undergone prior fistula surgery with 5 (12 %) having had three or more previous operations. All patients underwent the diagnostic phase as well as diathermy and curettage of the fistula tracts during VAAFT. Primary healing rate was 70.7 % at a median follow-up of 34 months. Twelve patients recurred or did not heal and underwent a repeat VAAFT procedure utilising various methods of dealing with the internal opening. There was a secondary healing rate of 83 % with two recurrences. Overall, stapling of the internal opening had a 22 % recurrence rate, while anorectal advancement flap had a 75 % failure rate. There was no recurrence seen in six cases after using the over-the-scope-clip (OTSC(®)) system to secure the internal opening. VAAFT is useful in the identification of fistula tracts and enables closure of the internal opening. Adequate closure is essential with the method used to close large or fibrotic internal openings being the determining factor for success or failure. The OTSC system delivered the most consistent result without leaving a substantial perianal wound. Ensuring thorough curettage and drainage of the tract during VAAFT is also important to facilitate healing. We believe that this understanding will bring about a decrease in the high recurrence rates currently seen in many series of anal fistulae.

Can Vacuum Assisted Venous Drainage be Achieved using a Roller Pump in an Emergency? A Pilot Study using Neonatal Circuitry

PubMed Central

Hill, S. L.; Holt, D. W.

2007-01-01

Abstract: There has been much advancement in perfusion technology over its 50 years of progression. One of these techniques is vacuum-assisted venous drainage (VAVD). Many perfusionists augment venous drainage using VAVD, typically from a wall vacuum source. This study explores alternates to providing VAVD if the wall vacuum fails. In two porcine laboratories, ∼36 in. of 3/16-in. tubing was connected to a sucker return port and placed into the roller head next to the arterial pump. The vacuum was monitored with a DLP pressure monitoring system (Medtronic). This system was connected to small-bore tubing and attached to a stopcock on top of the reservoir. The vacuum was regulated using another stopcock connected to a non-filtered luer lock port on top of the reservoir or by a segment of 3 × 0.25-in.-diameter tubing attached to the vent port with a c-clamp. Vacuum drainage was achieved, ranging from −18 mmHg to −71 mmHg by manipulating the stopcock or c-clamp. Changes in venous drainage were seen by volume fluctuations in the venous reservoir. The vacuum was adjusted to account for dramatic changes. Augmented venous drainage using a roller pump can be achieved successfully during cardiopulmonary bypass (CPB). This method of active drainage can be used in lieu of wall suction or during times of emergency if wall suction fails. PMID:18293812

A new model for simulating spring discharge recession and estimating effective porosity of karst aquifers

NASA Astrophysics Data System (ADS)

Xu, Bin; Ye, Ming; Dong, Shuning; Dai, Zhenxue; Pei, Yongzhen

2018-07-01

Quantitative analysis of recession curves of karst spring hydrographs is a vital tool for understanding karst hydrology and inferring hydraulic properties of karst aquifers. This paper presents a new model for simulating karst spring recession curves. The new model has the following characteristics: (1) the model considers two separate but hydraulically connected reservoirs: matrix reservoir and conduit reservoir; (2) the model separates karst spring hydrograph recession into three stages: conduit-drainage stage, mixed-drainage stage (with both conduit drainage and matrix drainage), and matrix-drainage stage; and (3) in the mixed-drainage stage, the model uses multiple conduit layers to present different levels of conduit development. The new model outperforms the classical Mangin model and the recently developed Fiorillo model for simulating observed discharge at the Madison Blue Spring located in northern Florida. This is attributed to the latter two characteristics of the new model. Based on the new model, a method is developed for estimating effective porosity of the matrix and conduit reservoirs for the three drainage stages. The estimated porosity values are consistent with measured matrix porosity at the study site and with estimated conduit porosity reported in literature. The new model for simulating karst spring hydrograph recession is mathematically general, and can be applied to a wide range of karst spring hydrographs to understand groundwater flow in karst aquifers. The limitations of the model are discussed at the end of this paper.

Surgical vs ultrasound-guided drainage of deep neck space abscesses: a randomized controlled trial: surgical vs ultrasound drainage

PubMed Central

2013-01-01

Introduction Deep neck space abscesses (DNAs) are relatively common otolaryngology-head and neck surgery emergencies and can result in significant morbidity with potential mortality. Traditionally, surgical incision and drainage (I&D) with antibiotics has been the mainstay of treatment. Some reports have suggested that ultrasound-guided drainage (USD) is a less invasive and effective alternative in select cases. Objectives To compare I&D vs USD of well-defined DNAs, using a randomized controlled clinical trial design. The primary outcome measure was effectiveness (length of hospital stay (LOHS) and safety), and the secondary outcome measure was overall cost to the healthcare system. Methods Patients presenting to the University of Alberta Emergency Department with a well-defined deep neck space abscess were recruited in the study. Patients were randomized to surgical or US-guided drainage, placed on intravenous antibiotics and admitted with airway precautions. Following drainage with either intervention, abscess collections were cultured and drains were left in place until discharge. Results Seventeen patients were recruited in the study. We found a significant difference in mean LOHS between patients who underwent USD (3.1 days) vs I&D (5.2 days). We identified significant cost savings associated with USD with a 41% cost reduction in comparison to I&D. Conclusions USD drainage of deep neck space abscesses in a certain patient population is effective, safe, and results in a significant cost savings to the healthcare system. PMID:23672735

Reconstruction of North American drainage basins and river discharge since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Wickert, Andrew D.

2016-11-01

Over the last glacial cycle, ice sheets and the resultant glacial isostatic adjustment (GIA) rearranged river systems. As these riverine threads that tied the ice sheets to the sea were stretched, severed, and restructured, they also shrank and swelled with the pulse of meltwater inputs and time-varying drainage basin areas, and sometimes delivered enough meltwater to the oceans in the right places to influence global climate. Here I present a general method to compute past river flow paths, drainage basin geometries, and river discharges, by combining models of past ice sheets, glacial isostatic adjustment, and climate. The result is a time series of synthetic paleohydrographs and drainage basin maps from the Last Glacial Maximum to present for nine major drainage basins - the Mississippi, Rio Grande, Colorado, Columbia, Mackenzie, Hudson Bay, Saint Lawrence, Hudson, and Susquehanna/Chesapeake Bay. These are based on five published reconstructions of the North American ice sheets. I compare these maps with drainage reconstructions and discharge histories based on a review of observational evidence, including river deposits and terraces, isotopic records, mineral provenance markers, glacial moraine histories, and evidence of ice stream and tunnel valley flow directions. The sharp boundaries of the reconstructed past drainage basins complement the flexurally smoothed GIA signal that is more often used to validate ice-sheet reconstructions, and provide a complementary framework to reduce nonuniqueness in model reconstructions of the North American ice-sheet complex.

Acid-base accounting to predict post-mining drainage quality on surface mines.

PubMed

Skousen, J; Simmons, J; McDonald, L M; Ziemkiewicz, P

2002-01-01

Acid-base accounting (ABA) is an analytical procedure that provides values to help assess the acid-producing and acid-neutralizing potential of overburden rocks prior to coal mining and other large-scale excavations. This procedure was developed by West Virginia University scientists during the 1960s. After the passage of laws requiring an assessment of surface mining on water quality, ABA became a preferred method to predict post-mining water quality, and permitting decisions for surface mines are largely based on the values determined by ABA. To predict the post-mining water quality, the amount of acid-producing rock is compared with the amount of acid-neutralizing rock, and a prediction of the water quality at the site (whether acid or alkaline) is obtained. We gathered geologic and geographic data for 56 mined sites in West Virginia, which allowed us to estimate total overburden amounts, and values were determined for maximum potential acidity (MPA), neutralization potential (NP), net neutralization potential (NNP), and NP to MPA ratios for each site based on ABA. These values were correlated to post-mining water quality from springs or seeps on the mined property. Overburden mass was determined by three methods, with the method used by Pennsylvania researchers showing the most accurate results for overburden mass. A poor relationship existed between MPA and post-mining water quality, NP was intermediate, and NNP and the NP to MPA ratio showed the best prediction accuracy. In this study, NNP and the NP to MPA ratio gave identical water quality prediction results. Therefore, with NP to MPA ratios, values were separated into categories: <1 should produce acid drainage, between 1 and 2 can produce either acid or alkaline water conditions, and >2 should produce alkaline water. On our 56 surface mined sites, NP to MPA ratios varied from 0.1 to 31, and six sites (11%) did not fit the expected pattern using this category approach. Two sites with ratios <1 did not produce acid drainage as predicted (the drainage was neutral), and four sites with a ratio >2 produced acid drainage when they should not have. These latter four sites were either mined very slowly, had nonrepresentative ABA data, received water from an adjacent underground mine, or had a surface mining practice that degraded the water. In general, an NP to MPA ratio of <1 produced mostly acid drainage sites, between 1 and 2 produced mostly alkaline drainage sites, while NP to MPA ratios >2 produced alkaline drainage with a few exceptions. Using these values, ABA is a good tool to assess overburden quality before surface mining and to predict post-mining drainage quality after mining. The interpretation from ABA values was correct in 50 out of 52 cases (96%), excluding the four anomalous sites, which had acid water for reasons other than overburden quality.

Percutaneous Treatment of Congenital Splenic Cysts: Drainage and Sclerotherapy with Polidocanol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goktay, A. Yigit, E-mail: yigit.goktay@deu.edu.tr, E-mail: goktayay@superonline.com; Secil, Mustafa; Ozcan, Mehmet Ali

2006-06-15

Congenital 'true' splenic cysts are rare lesions. Therapeutic methods for the management of these lesions have been based on preserving splenic function due to the immunologic role of spleen. We report three different cases of congenital splenic cysts treated by percutaneous drainage and polidocanol sclerotherapy. This less invasive treatment appears to be safe and effective after 6 to 36 months of follow-up.

Design and Modification of an Installation Method to Stabilize Small Trapezoidal Flumes in Drainage Ditches

Treesearch

Charles A. Harrison; Susan O’Ney

2002-01-01

We developed procedures for installing prefabricated trapezoidal flumes in deep (10 to 12 feet) drainage ditches to monitor hydrologic functions and provide gauge locations for sampling discharge. Flows from the instrumented basins were generally low, but the ditches were occasionally subject to high flows caused by rain events of 2 to 3 inches or more. These high flow...

The use of a water seal to manage air leaks after a pulmonary lobectomy: a retrospective study.

PubMed

Okamoto, Junichi; Okamoto, Tatsuro; Fukuyama, Yasuro; Ushijima, Chie; Yamaguchi, Masafumi; Ichinose, Yukito

2006-08-01

The methods for managing chest drainage tubes during the postoperative period differ among thoracic surgeons and, as a result, the optimal method remains controversial. We reviewed 170 consecutive patients undergoing a pulmonary lobectomy for either primary lung cancer or metastatic lung cancer from January 1998 to December 2002. After the operation, the chest drainage tube was placed on a suction pump with a negative pressure of -10 cmH(2)O in 120 patients before 2001, while such drainage tubes were kept on water seal in 47 cases mainly since 2001. Regarding the preoperative and postoperative variables, postoperative air leak as well as the video-assisted thoracic surgery (VATS) procedure were more frequently observed in the water seal group than in the suction group (p=0.01580, p<0.001, respectively). In comparing these different populations, each Kaplan-Meier curve, which presented the duration of the postoperative air leak seemed to be similar between the two methods. These observations suggest that applying chest tubes on water seal seems to be an effective method for preventing postoperative air leak in clinical practice. However, a prospective randomized trial using a larger series of patients is warranted for this subject.

Half versus full vacuum suction drainage after modified radical mastectomy for breast cancer- a prospective randomized clinical trial[ISRCTN24484328

PubMed Central

Chintamani; Singhal, Vinay; Singh, JP; Bansal, Anju; Saxena, Sunita

2005-01-01

Background Suction drains are routinely used after modified radical mastectomy and are an important factor contributing to increased hospital stay as the patients are often discharged only after their removal. Amongst various factors that influence the amount of postoperative drainage, the negative suction pressure applied to the drain has been reported to be of great significance. While a high negative suction pressure is expected to drain the collection and reduce the dead space promptly, it may also prevent the leaking lymphatics from closing and lead to increased drainage from the wound. Against this background a prospective randomized clinical study was conducted to compare the amount and duration of drainage between a half negative suction and full vacuum suction drainage in patients following modified radical mastectomy. The associated postoperative morbidity was also compared between the two groups. Methods 85 FNAC (fine needle aspiration cytology) proven cases of locally advanced breast cancer were randomized. (Using randomly ordered sealed envelops, which were opened immediately before the closure of the wound) in to 50 patients with full vacuum suction (pressure = 700 g/m2) and 35 cases in to half vacuum suction drainage (pressure = 350 g/m2) groups. The two groups were comparable in respect of age, weight, and technique of operation and extent of axillary dissection. Surgery was performed by the same surgical team comprising of five surgeons (two senior and three resident surgeons) using a standardized technique with electrocautery. External compression dressing was provided over the axilla for first 48 hrs and following that patients were encouraged to do active and passive shoulder exercises. The outcomes measured were postoperative morbidity and the length of hospital stay. Statistical methods used: Descriptive studies were performed with SPSS version 10 and group characteristics were compared using student t-test. Results Half vacuum suction drains were removed earlier than the full suction vacuum suction drains. There was no significant difference in the incidence of seroma formation in the two groups and there was a significant reduction in the total hospital stay in patients with half vacuum suction drainage systems as compared to the full suction drainage group (p < 0.001) without any added morbidity. Conclusions Half negative suction drains provide an effective compromise between no suction and full or high suction drainage after modified radical mastectomy by reducing the hospital stay and the post operative morbidity including post operative seromas. PMID:15676064

Role of endoscopic biliary drainage in advanced hepatocellular carcinoma with jaundice

PubMed Central

Han, Sung Yong; Heo, Jeong; Kim, Dong Uk; Baek, Dong Hoon; Yoo, So Yong; Kim, Chang Won; Kim, Suk; Song, Geun Am; Cho, Mong; Kang, Dae Hwan

2017-01-01

Background Patients with advanced hepatocellular carcinoma (HCC) with jaundice have an extremely poor prognosis. Although biliary drainage can resolve obstructive jaundice, signs of obstruction may not be evident. This study evaluated the role of endoscopic biliary drainage in patients with advanced HCC and obstructive jaundice. Methods From 2010 to 2015, 74 patients underwent endoscopic biliary drainage for obstructive jaundice due to advanced HCC. Jaundice resolution was defined as complete response and total bilirubin concentration below 3 mg/dl. Results The technical success rate in the 74 patients was 92.1% (70/76). Of the 70 patients who underwent successful biliary drainage, 48 (68.6%) and 22 (31.4%) were Child-Pugh classes B and C, respectively, and 10 (14.3%) and 60 (85.7%) were BCLC stages B and C, respectively. Intrahepatic bile duct (IHD) dilatation was observed in 35 patients (50%). After drainage, the complete response rate was 35.7% (25/70). The mean time to resolution was 17.4 ±8.5 days. However, jaundice was re-aggravated in 74.3% (15/25) after a mean 103.5 ±96.4 days. Multivariate analysis showed that the absence of ascites, presence of IHD dilatation, normal range of prothrombin time, and lower MELD score were significantly associated with complete response. The overall survival rate was 15.7% (11/70) and the median survival time is 28 days (95% confidence interval 2.6–563 days). Complete response and HCC treatment after drainage were significantly associated with survival. Conclusion Effective endoscopic biliary drainage is an important palliative treatment in patients with advanced HCC and obstructive jaundice, especially those with IHD dilatation and preserved liver function, as determined by ascites, prothrombin time, and MELD score. PMID:29095941

Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

NASA Astrophysics Data System (ADS)

Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

2018-01-01

Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

Drain Insertion in Chronic Subdural Hematoma: An International Survey of Practice.

PubMed

Soleman, Jehuda; Kamenova, Maria; Lutz, Katharina; Guzman, Raphael; Fandino, Javier; Mariani, Luigi

2017-08-01

To investigate whether, after the publication of grade I evidence that it reduces recurrence rates, the practice of drain insertion after burr-hole drainage of chronic subdural hematoma has changed. Further, we aimed to document various practice modalities concerning the insertion of a drain adopted by neurosurgeons internationally. We administered a survey to neurosurgeons worldwide with questions relating to the surgical treatment of chronic subdural hematoma, with an emphasis on their practices concerning the use of a drain. The preferred surgical technique was burr-hole drainage (89%). Most surgeons prefer to place a drain (80%), whereas in 56% of the cases the reason for not placing a drain was brain expansion after evacuation. Subdural drains are placed by 50% and subperiosteal drains by 27% of the responders, whereas 23% place primarily a subdural drain if possible and otherwise a subperiosteal drain. Three quarters of the responders leave the drain for 48 hours and give prophylactic antibiotic treatment, mostly a single-shot dose intraoperatively (70%). Routine postoperative computed tomography is done by 59% mostly within 24-48 hours after surgery (94%). Adjunct treatment to surgery rarely is used (4%). The publication of grade I evidence in favor of drain use influenced positively this practice worldwide. Some surgeons are still reluctant to insert a drain, especially when the subdural space is narrow after drainage of the hematoma. The insertion of a subperiosteal drain could be a good alternative solution. However, its outcome and efficacy must be evaluated in larger studies. Copyright © 2017 Elsevier Inc. All rights reserved.

A method for estimating peak and time of peak streamflow from excess rainfall for 10- to 640-acre watersheds in the Houston, Texas, metropolitan area

USGS Publications Warehouse

Asquith, William H.; Cleveland, Theodore G.; Roussel, Meghan C.

2011-01-01

Estimates of peak and time of peak streamflow for small watersheds (less than about 640 acres) in a suburban to urban, low-slope setting are needed for drainage design that is cost-effective and risk-mitigated. During 2007-10, the U.S. Geological Survey (USGS), in cooperation with the Harris County Flood Control District and the Texas Department of Transportation, developed a method to estimate peak and time of peak streamflow from excess rainfall for 10- to 640-acre watersheds in the Houston, Texas, metropolitan area. To develop the method, 24 watersheds in the study area with drainage areas less than about 3.5 square miles (2,240 acres) and with concomitant rainfall and runoff data were selected. The method is based on conjunctive analysis of rainfall and runoff data in the context of the unit hydrograph method and the rational method. For the unit hydrograph analysis, a gamma distribution model of unit hydrograph shape (a gamma unit hydrograph) was chosen and parameters estimated through matching of modeled peak and time of peak streamflow to observed values on a storm-by-storm basis. Watershed mean or watershed-specific values of peak and time to peak ("time to peak" is a parameter of the gamma unit hydrograph and is distinct from "time of peak") of the gamma unit hydrograph were computed. Two regression equations to estimate peak and time to peak of the gamma unit hydrograph that are based on watershed characteristics of drainage area and basin-development factor (BDF) were developed. For the rational method analysis, a lag time (time-R), volumetric runoff coefficient, and runoff coefficient were computed on a storm-by-storm basis. Watershed-specific values of these three metrics were computed. A regression equation to estimate time-R based on drainage area and BDF was developed. Overall arithmetic means of volumetric runoff coefficient (0.41 dimensionless) and runoff coefficient (0.25 dimensionless) for the 24 watersheds were used to express the rational method in terms of excess rainfall (the excess rational method). Both the unit hydrograph method and excess rational method are shown to provide similar estimates of peak and time of peak streamflow. The results from the two methods can be combined by using arithmetic means. A nomograph is provided that shows the respective relations between the arithmetic-mean peak and time of peak streamflow to drainage areas ranging from 10 to 640 acres. The nomograph also shows the respective relations for selected BDF ranging from undeveloped to fully developed conditions. The nomograph represents the peak streamflow for 1 inch of excess rainfall based on drainage area and BDF; the peak streamflow for design storms from the nomograph can be multiplied by the excess rainfall to estimate peak streamflow. Time of peak streamflow is readily obtained from the nomograph. Therefore, given excess rainfall values derived from watershed-loss models, which are beyond the scope of this report, the nomograph represents a method for estimating peak and time of peak streamflow for applicable watersheds in the Houston metropolitan area. Lastly, analysis of the relative influence of BDF on peak streamflow is provided, and the results indicate a 0:04log10 cubic feet per second change of peak streamflow per positive unit of change in BDF. This relative change can be used to adjust peak streamflow from the method or other hydrologic methods for a given BDF to other BDF values; example computations are provided.

Tisseel does not reduce postoperative drainage, length of stay, and transfusion requirements for lumbar laminectomy with noninstrumented fusion versus laminectomy alone.

PubMed

Epstein, Nancy E

2015-01-01

Typically, fibrin sealants (FSs) and fibrin glues (FGs) are used to strengthen dural repairs during spinal surgery. In 2014, Epstein demonstrated that one FS/FG, Tisseel (Baxter International Inc., Westlake Village, CA, USA) equalized the average times to drain removal and length of stay (LOS) for patients with versus without excess bleeding (e.g. who did not receive Tisseel) undergoing multilevel laminectomies with 1-2 level noninstrumented fusions (LamF).[6]. Here Tisseel was utilized to promote hemostasis for two populations; 39 patients undergoing average 4.4 level lumbar laminectomies with average 1.3 level noninstrumented fusions (LamF), and 48 patients undergoing average 4.0 level laminectomies alone (Lam). We compared the average operative time, estimated blood loss (EBL), postoperative drainage, LOS, and transfusion requirements for the LamF versus Lam groups. The average operative times, EBL, postoperative drainage, LOS, and transfusion requirements were all greater for LamF versus Lam patients; operative times (4.1 vs. 3.0 h), average EBL (192.3 vs. 147.9 cc), drainage (e.g. day 1; 199.6 vs. 167.4 cc; day 2; 172.9 vs. 63.9 cc), average LOS (4.6 vs. 2.5 days), and transfusion requirements (11 LamF patients; 18 Units [U] RBC versus 2 Lam patients; 3 U RBC). Utilizing Tisseel to facilitate hemostasis in LamF versus Lam still resulted in greater operative times, EBL, postoperative average drainage, LOS, and transfusion requirements for patients undergoing the noninstrumented fusions. Although Tisseel decreases back bleeding within the spinal canal, it does not reduce blood loss from LamF decorticated transverse processes.

Time-integrated Monitoring of Polychlorinated Dibenzo-p-dioxins and Polychlorinated Dibenzofurans (PCDD/Fs) in Urban and Industrial Wastewaters Using a Ceramic Toximeter and the CALUX Bioassay

PubMed Central

Addeck, Amr; Croes, Kim; Van Langenhove, Kersten; Denison, Michael S.; Elhamalawy, Ahmed; Elskens, Marc; Baeyens, Willy

2015-01-01

The ceramic toximeter as a passive sampler in combination with the CALUX bioassay was utilized as a time-integrated pollution-assessment technique for dioxin-like PCDD/Fs in wastewaters. Toximeters filled with XCARB and enclosed in stainless steel cages were submerged in wastewater of Belbeis drainage-canal and EMAK paper-mill, located in Egypt, for 28 days. Two samplers were removed every week from each site. Extracts from toximeters, from bottom-sediments, and from paper-mill sludge were analyzed by the CALUX. Results showed a regular increase in the amounts of PCDD/Fs trapped by the toximeters as sampling time increased. Time-weighted average concentrations (TWA) of PCDD/Fs in the wastewaters of the drainage-canal and paper-mill were 231 (214-281) and 26 (24.1-32.6) pg-BEQ L-1, respectively. Compared to literature data, this means a high pollution level for the drainage-canal water, while the pollution level in the paper-mill wastewater is similar to that reported for other paper mills. The PCDD/Fs levels in the drainage-canal bottom-sediments and in the paper-mill sludge were 8.3 and 14.6 pg-BEQ g-1 dry-weight, at the lower end of internationally reported values in similar compartments. The sampling rate of the tested toximeters for dissolved PCDD/Fs was about 3.6 mL d-1. Sediment/water partitioning coefficient log Kd of PCDD/Fs in the drainage-canal and the paper-mill was 1.42 and 2.70 respectively. The organic-carbon normalized partition coefficient log Koc was 4.17 and 3.19 respectively, and is lower than the reported values for other sites. PMID:24075528

Time-integrated monitoring of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in urban and industrial wastewaters using a ceramic toximeter and the CALUX bioassay.

PubMed

Addeck, Amr; Croes, Kim; Van Langenhove, Kersten; Denison, Michael S; Elhamalawy, Ahmed; Elskens, Marc; Baeyens, Willy

2014-01-01

The ceramic toximeter as a passive sampler in combination with the CALUX bioassay was utilized as a time-integrated pollution-assessment technique for dioxin-like PCDD/Fs in wastewaters. Toximeters filled with XCARB and enclosed in stainless steel cages were submerged in wastewater of Belbeis drainage-canal and EMAK paper-mill, located in Egypt, for 28 days. Two samplers were removed every week from each site. Extracts from toximeters, from bottom-sediments, and from paper-mill sludge were analyzed by the CALUX. Results showed a regular increase in the amounts of PCDD/Fs trapped by the toximeters as sampling time increased. Time-weighted average concentrations (TWA) of PCDD/Fs in the wastewaters of the drainage-canal and paper-mill were 231 (214-281) and 26 (24.1-32.6) pg-BEQL(-1), respectively. Compared to literature data, this means a high pollution level for the drainage-canal water, while the pollution level in the paper-mill wastewater is similar to that reported for other paper mills. The PCDD/Fs levels in the drainage-canal bottom-sediments and in the paper-mill sludge were 8.3 and 14.6 pg-BEQg(-1) dry-weight, at the lower end of internationally reported values in similar compartments. The sampling rate of the tested toximeters for dissolved PCDD/Fs was about 3.6 mL d(-1). Sediment/water partitioning coefficient logKd of PCDD/Fs in the drainage-canal and the paper-mill was 1.42 and 2.70 respectively. The organic-carbon normalized partition coefficient logKoc was 4.17 and 3.19 respectively, and is lower than the reported values for other sites. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of hillslope gully stabilization on erosion and sediment production in the Torreon Wash watershed, New Mexico, 2009–12

USGS Publications Warehouse

Matherne, Anne Marie; Tillery, Anne C.; Douglas-Mankin, Kyle R.

2018-04-10

Sediment erosion and deposition in two sets of paired (treated and untreated) upland drainages in the Torreon Wash watershed, upper Rio Puerco Basin, New Mexico, were examined over a 3 1/2-year period from spring 2009 through fall 2012. The objective was to evaluate the effectiveness of shallow, loose-stone check dams, or “one-rock dams,” as a hillslope gully erosion stabilization and mitigation method, and its potential for retaining upland eroded soils and decreasing delivery of sediment to lower ephemeral stream channels. Two high-resolution topographic surveys, completed at the beginning and end of the study period, were used to assess the effects of the mitigation measures at paired-drainage sites in both Penistaja Arroyo and Papers Wash watersheds, and at six main-stem-channel cross-section clusters along Penistaja Arroyo and Torreon Wash in the Torreon Wash watershed.For both drainage pairs, the treated drainage had greater sediment aggradation near the channel than the untreated drainage. Erosion was the dominant geomorphic process in the untreated Penistaja Arroyo drainage, whereas aggradation was the dominant process in the other three drainages. For the Penistaja Arroyo paired drainages, the treated site showed a 51-percent increase in area aggraded and 67-percent increase in volume aggraded per area analyzed over the untreated site. Both Papers Wash drainages showed net aggradation, but with similar treatment effect, with the treated site showing a 29-percent increase in area aggraded and 60-percent increase in volume aggraded per area analyzed over the untreated site. In the untreated Penistaja Arroyo drainage, the calculated minimum erosion rate was 0.0055 inches per year (in/yr; 0.14 millimeters per year [mm/yr]), whereas the calculated aggradation rates for the three drainages for which aggradation was the dominant geomorphic process were 0.0063 in/yr (0.16 mm/yr) for the Penistaja Arroyo treated drainage, 0.012 in/yr (0.31 mm/yr) for the Papers Wash untreated drainage, and 0.988 in/yr (2.51 mm/yr) for the Papers Wash treated drainage.Changes in the channel cross section along the main-stem Penistaja Arroyo and Torreon Wash were also examined. Channel-bank slumping and erosion of previously deposited bed material were apparent sources for sediment suspended in ephemeral streamflow. Cross-sectional channel surveys indicated examples of both erosion and deposition along each channel over the study period. Because the drainage area of the treated drainages is small compared to that of the Torreon Wash watershed, the upland mitigation measures would not be expected to measurably affect short-term concentrations of suspended sediment in main-stem channels.One-rock-dam mitigation structures in the upland drainages appear to have resulted in a decrease in sediment delivery to the main-stem channel. One-rock-dam mitigation structures may affect streamflow through their influence on runoff volume (via infiltration) and runoff rate (via detention), both of which may vary with time after structure installation.

National Dam Safety Program. West Millpond Dam (NY 01060), Mohawk River Basin, City of Gloversville, Fulton County, New York. Phase I Inspection Report,

DTIC Science & Technology

1981-09-02

numerous and constantly changing internal and external con- ditions, and is evolutionary in nature. It would be incorrect to assume that the present...to seepage and piping ( internal erosion) problems if a tree blows over and pulls out its roots or if a tree dies and its roots rot. The roots of...for the actual size of the drainage area (same for 10 square miles or less) were inputted to the program as percentages of the index PKF in

77 FR 2974 - Longview Energy Exchange, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-20

... system; (2) a single lower reservoir dam constructed of earth fill materials with an internal dam drainage system; (3) concrete inlet-outlet structures at both upper reservoirs equipped with trash racks..., using the eComment system at http://www.ferc.gov/docs-filing/ecomment.asp . You must include your name...

Assessment of the use of latissimus dorsi restoration during modified radical mastectomy in breast cancer patients

PubMed Central

Yang, Chao; Wang, Xinle; Zhang, Geng; Yang, Liu; Guo, Xuan; Wang, Xue; Song, Zhenchuan

2017-01-01

The incision area of modified radical mastectomy in breast cancer patients is associated with subcutaneous effusion and skin flap necrosis as the most common complications. The aim of the present study was to assess the effect of latissimus dorsi restoration during modified radical mastectomy in breast cancer patients by evaluating 365 cases. Among these cases, 185 received modified radical mastectomy combined with intraoperative latissimus dorsi restoration, while 180 received modified radical mastectomy alone. The flap tension, drainage fluid amount and extubation time were compared between the two methods. The flap tension in patients who received modified radical mastectomy combined with intraoperative latissimus dorsi restoration was significantly lower and the blood supply was better. After surgery, the drainage fluid amount was also significantly lower in these patients compared with the control group. Furthermore, the mean time to drainage tube removal was significantly shorter in these patients and the postoperative cosmetic outcome was superior. Thus, it was concluded that modified radical mastectomy combined with intraoperative latissimus dorsi restoration in breast cancer patients was associated with reduced drainage fluid effusion, shorter hospitalization time and decreased flap tension. Overall, this method appears to be potentially suitable for extensive application in the clinical setting. PMID:29285380

Novel use of pleural ultrasound can identify malignant entrapped lung prior to effusion drainage.

PubMed

Salamonsen, Matthew R; Lo, Ada K C; Ng, Arnold C T; Bashirzadeh, Farzad; Wang, William Y S; Fielding, David I K

2014-11-01

The presence of entrapped lung changes the appropriate management of malignant pleural effusion from pleurodesis to insertion of an indwelling pleural catheter. No methods currently exist to identify entrapped lung prior to effusion drainage. Our objectives were to develop a method to identify entrapped lung using tissue movement and deformation (strain) analysis with ultrasonography and compare it to the existing technique of pleural elastance (PEL). Prior to drainage, 81 patients with suspected malignant pleural effusion underwent thoracic ultrasound using an echocardiogram machine. Images of the atelectatic lower lobe were acquired during breath hold, allowing motion and strain related to the cardiac impulse to be analyzed using motion mode (M mode) and speckle-tracking imaging, respectively. PEL was measured during effusion drainage. The gold-standard diagnosis of entrapped lung was the consensus opinion of two interventional pulmonologists according to postdrainage imaging. Participants were randomly divided into development and validation sets. Both total movement and strain were significantly reduced in entrapped lung. Using data from the development set, the area under the receiver-operating curves for the diagnosis of entrapped lung was 0.86 (speckle tracking), 0.79 (M mode), and 0.69 (PEL). Using respective cutoffs of 6%, 1 mm, and 19 cm H2O on the validation set, the sensitivity/specificity was 71%/85% (speckle tracking), 50%/85% (M mode), and 40%/100% (PEL). This novel ultrasound technique can identify entrapped lung prior to effusion drainage, which could allow appropriate choice of definitive management (pleurodesis vs indwelling catheter), reducing the number of interventions required to treat malignant pleural effusion.

Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

DOEpatents

Anderson, R.N.; Boulanger, A.; Bagdonas, E.P.; Xu, L.; He, W.

1996-12-17

The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells. 22 figs.

Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

DOEpatents

Anderson, Roger N.; Boulanger, Albert; Bagdonas, Edward P.; Xu, Liqing; He, Wei

1996-01-01

The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells.

Analysis of different ways of drainage for obstructive jaundice caused by hilar cholangiocarcinoma.

PubMed

Xu, Chuan; Lv, Peng-Hua; Huang, Xin-En; Wang, Shu-Xiang; Sun, Ling; Wang, Fu-An

2014-01-01

To evaluate the prognosis of different ways of drainage for patients with obstructive jaundice caused by hilar cholangiocarcinoma. During the period of January 2006- March 2012, percutaneous transhepatic catheter drainage (PTCD)/ percutaneous transhepatic biliary stenting (PTBS) were performed for 89 patients. According to percutaneous transhepatic cholangiography (PTC), external drainage was selected if the region of obstruction could not be passed by guide wire or a metallic stent was inserted if it could. External drainage was the first choice if infection was diagnosed before the procedure, and a metallic stent was inserted in one week after the infection was under control. Selection by new infections, the degree of bilirubin decrease, the change of ALT, the time of recurrence of obstruction, and the survival time of patients as the parameters was conducted to evaluate the methods of different interventional treatments regarding prognosis of patients with hilar obstruction caused by hilar cholangiocarcinoma. PTCD was conducted in 6 patients and PTBS in 7 (p<0.05). Reduction of bilirubin levels and ALT levels was obvious after the procedures (p<0.05). The average survival time with PTCD was 161 days and with PTBS was 243 days (p<0.05). With both drainage procedures for obstructive jaundice caused by hilar cholangiocarcinoma improvement in liver function was obvious. PTBS was found to be better than PTCD for prolonging the patient survival.

Water quality in irrigation and drainage networks of Thessaloniki plain in Greece related to land use, water management, and agroecosystem protection.

PubMed

Litskas, Vassilis D; Aschonitis, Vassilis G; Antonopoulos, Vassilis Z

2010-04-01

A representative agricultural area of 150 ha located in a protected ecosystem (Axios River Delta, Thermaikos Gulf-N. Aegean, Greece) was selected in order to investigate water quality parameters [pH, electrical conductivity (EC(w)), NO(3)-N, NH(4)-N, total phosphorus (TP)] in irrigation and drainage water. In the study area, the cultivated crops are mainly rice, maize, cotton, and fodder. Surface irrigation methods are applied using open channels network, and irrigation water is supplied by Axios River, which is facing pollution problems. The return flow from surface runoff and the surplus of irrigation water are collected to drainage network and disposed to Thermaikos Gulf. A 2-year study (2006-2007) was conducted in order to evaluate the effects of land use and irrigation water management on the drainage water quality. The average pH and NO(3)-N concentration was higher in the irrigation water (8.0 and 1.3 mg/L, respectively) than that in the drainage water (7.6 and 1.0 mg/L, respectively). The average EC(W), NH(4)-N, and TP concentration was higher in the drainage water (1,754 muS/cm, 90.3 microg/L, and 0.2 mg/L, respectively) than that in the irrigation water (477.1 muS/cm, 46.7 microg/L, and 0.1 mg/L, respectively). Average irrigation efficiency was estimated at 47% and 51% in 2006 and 2007 growing seasons (April-October), respectively. The loads of NO(3)-N in both seasons were higher in the irrigation water (35.1 kg/ha in 2006 and 24.9 kg/ha in 2007) than those in the drainage water (8.1 kg/ha in 2006 and 7.6 kg/ha in 2007). The load of TP was higher in the irrigation water in season 2006 (2.8 kg/ha) than that in the drainage water (1.1 kg/ha). Total phosphorus load in 2007 was equal in irrigation and drainage water (1.2 kg/ha). Wetland conditions, due to rice irrigation regime, drainage network characteristics, and the crop distribution in the study area, affect the drainage water ending in the protected ecosystem of Thermaikos Gulf.

Treatment of Intra-abdominal Abscesses in Crohn’s Disease – A Nationwide Analysis of Patterns and Outcomes of Care

PubMed Central

Ananthakrishnan, Ashwin N; McGinley, Emily L

2013-01-01

Background Abdominal abscesses are a common complication in Crohn’s disease (CD). Percutaneous drainage of such abscesses has become increasingly popular and may deliver outcomes comparable to surgical treatment; however, such comparative data are limited from single center studies. There have been no nationally representative studies comparing different treatment modalities for abdominal abscesses. Methods We identified all adult CD-related non-elective hospitalizations from the Nationwide Inpatient Sample 2007 that were complicated by an intra-abdominal abscess. Treatment modality was categorized into 3 strata – medical treatment alone, percutaneous drainage, and surgery. We analyzed the nationwide patterns in the treatment and outcomes of each treatment modality and examined for patient demographic, disease, or hospital-related disparities in treatment and outcome. Results There were an estimated 3,296 hospitalizations for abdominal abscesses in patients with CD. Approximately 39% were treated by medical treatment alone, 29% with percutaneous drainage, and 32% with surgery with a significant increase in the use of percutaneous drainage since 1998 (7%). Co-morbidity burden, admission to a teaching hospital, and complicated Crohn’s disease (fistulae, stricture) were associated with non-medical treatment. Use of percutaneous drainage was more common in teaching hospitals. Mean time to percutaneous drainage and surgical treatment were 4.6 and 3.3 days respectively and early intervention was associated with significantly shorter hospitalization. Conclusions We describe the nationwide pattern in the treatment of abdominal abscesses and demonstrate an increase in the use of percutaneous drainage for the treatment of this subgroup. Early treatment intervention was predictive of shorter hospitalization. PMID:23392744

The role of invasive sonography in the differential diagnosis and treatment of intraabdominal fluid collections.

PubMed

Regöly-Mérei, J; Ihász, M; Szeberin, Z; Záborszky, A

Sixty-nine ultrasound-guided interventions (23 punctures and 46 drainages) were performed on 51 patients with the suspicion of intraabdominal abscess or another type of fluid collection in a prospective-controlled study. Of the procedures, 58.8% were carried out following surgery, while in 41.2% the indication were not related to prior surgical intervention. Repeated procedures were done in 10 patients. In the group of punctures the procedure was therapeutic in 3 cases and diagnostic in 16 patients. The drainage was technically successful in 92.7%. The drain was displaced or blocked in 27% (n = 10), but reinterventions were necessary in only 5 cases for this reason. The total number of redrainages was 18.9%. The percutaneous (pc) drainage was insufficient in 8 patients (21.6%), all these patients were operated on. 62.2% of the patients recovered after pc drainage, 13.5% following redrainage (total 75.5%). In 8.1% of the cases after pc drainage and in 5.4% after pc redrainage open surgery became necessary. There was only one complication due to the procedure. Seven patients (14.3%) died of the disease which indicated the procedure. There were no fatal outcomes on the account of the intervention. Ultrasound-guided puncture is a suitable method to indicate or contraindicate open surgery in the case of intraabdominal fluid collection. The diagnostic puncture may be followed by sonographically guided drainage or in selected cases by therapeutic puncture, but if the pc drainage is insufficient, open surgery should be performed in time.

Spatio-Temporal Changes of Lymphatic Contractility and Drainage Patterns following Lymphadenectomy in Mice

PubMed Central

Kwon, Sunkuk; Agollah, Germaine D.; Wu, Grace; Sevick-Muraca, Eva M.

2014-01-01

Objective To investigate the redirection of lymphatic drainage post-lymphadenectomy using non-invasive near-infrared fluorescence (NIRF) imaging, and to subsequently assess impact on metastasis. Background Cancer-acquired lymphedema arises from dysfunctional fluid transport after lymphadenectomy performed for staging and to disrupt drainage pathways for regional control of disease. However, little is known about the normal regenerative processes of the lymphatics in response to lymphadenectomy and how these responses can be accelerated, delayed, or can impact metastasis. Methods Changes in lymphatic “pumping” function and drainage patterns were non-invasively and longitudinally imaged using NIRF lymphatic imaging after popliteal lymphadenectomy in mice. In a cohort of mice, B16F10 melanoma was inoculated on the dorsal aspect of the paw 27 days after lymphadenectomy to assess how drainage patterns affect metastasis. Results NIRF imaging demonstrates that, although lymphatic function and drainage patterns change significantly in early response to popliteal lymph node (PLN) removal in mice, these changes are transient and regress dramatically due to a high regenerative capacity of the lymphatics and co-opting of collateral lymphatic pathways around the site of obstruction. Metastases followed the pattern of collateral pathways and could be detected proximal to the site of lymphadenectomy. Conclusions Both lymphatic vessel regeneration and co-opting of contralateral vessels occur following lymphadenectomy, with contractile function restored within 13 days, providing a basis for preclinical and clinical investigations to hasten lymphatic repair and restore contractile lymphatic function after surgery to prevent cancer-acquired lymphedema. Patterns of cancer metastasis after lymphadenectomy were altered, consistent with patterns of re-directed lymphatic drainage. PMID:25170770

Management of hilar cholangiocarcinoma in the North of England: Pathology, treatment, and outcome

PubMed Central

Mansfield, SD; Barakat, O; Charnley, RM; Jaques, BC; O’Suilleabhain, CB; Atherton, PJ; Manas, D

2005-01-01

AIM: To assess the management and outcome of hilar cholangiocarcinoma (Klatskin tumor) in a single tertiary referral center. METHODS: The notes of all patients with a diagnosis of hilar cholangiocarcinoma referred to our unit for over an 8-year period were identified and retrospectively reviewed. Presentation, management and outcome were assessed. RESULTS: Seventy-five patients were identified. The median age was 64 years (range 34-84 years). Male to female ratio was 1:1. Eighty-nine percent of patients presented with jaundice. Most patients referred were under Bismuth classification 3a, 3b or 4. Seventy patients required biliary drainage, 65 patients required 152 percutaneous drainage procedures, and 25 had other complications. Forty-one patients had 51 endoscopic drainage procedures performed (15 failed). Of these, 36 subsequently required percutaneous drainage. The median number of drainage procedures for all patients was three, 18 patients underwent resection (24%), nine had major complications and three died post-operatively. The 5-year survival rate was 4.2% for all patients, 21% for resected patients and 0% for those who did not undergo resection (P = 0.0021). The median number of admissions after diagnosis in resected patients was two and three in non-resected patients (P<0.05). Twelve patients had external-beam radiotherapy, seven brachytherapy, and eight chemotherapy. There was no significant benefit in terms of survival (P = 0.46) or hospital admissions. CONCLUSION: Resection increases survival but carries the risk of significant morbidity and mortality. Percutaneous biliary drainage is almost always necessary and endoscopic drainage should be avoided if possible. PMID:16437689

Twist drill craniostomy with closed drainage for chronic subdural haematoma in the elderly: an effective method.

PubMed

Ramnarayan, R; Arulmurugan, B; Wilson, Paul M; Nayar, Rani

2008-09-01

Chronic subdural haematoma is a disease of the elderly and surgery in these patients carries a much higher risk. The common surgical procedures for chronic subdural haematoma include twist drill craniostomy, burr hole evacuation or craniotomy. The aim of this study was to analyse the results of twist drill craniostomy with drainage in elderly patients with chronic subdural haematoma. Forty-two elderly patients (>65 years) with radiologically proven chronic subdural haematoma were analysed. All the patients underwent twist drill craniostomy and continuous drainage of the haematoma under local anaesthesia and total intravenous anaesthesia (TIVA). There were 24 males and 18 females. Headache and cognitive decline was seen in 50% and weakness of limbs in 60% of patients. CT scan was done in all cases. All patients underwent twist drill 2-3 cm in front of the parietal eminence under local anaesthesia. The drain was left for 24-72 h depending on the drainage. At 1 week, 88% of patients had a good outcome. Twist drill craniostomy with drainage under local anaesthesia is a safe and effective procedure for chronic subdural haematoma in the elderly and could be used as the first and only option in these people.

4R Water Quality Impacts: An Assessment and Synthesis of Forty Years of Drainage Nitrogen Losses.

PubMed

Christianson, L E; Harmel, R D

2015-11-01

The intersection of agricultural drainage and nutrient mobility in the environment has led to multiscale water quality concerns. This work reviewed and quantitatively analyzed nearly 1,000 site-years of subsurface tile drainage nitrogen (N) load data to develop a more comprehensive understanding of the impacts of 4R practices (application of the right source of nutrients, at the right rate and time, and in the right place) within drained landscapes across North America. Using drainage data newly compiled in the "Measured Annual Nutrient loads from AGricultural Environments" (MANAGE) database, relationships were developed across N application rates for nitrate N drainage loads and corn ( L.) yields. The lack of significant differences between N application timing or application method was inconsistent with the current emphasis placed on application timing, in particular, as a water quality improvement strategy ( = 0.934 and 0.916, respectively). Broad-scale analyses such as this can help identify major trends for water quality, but accurate implementation of the 4R approach will require site-specific knowledge to balance agronomic and environmental goals. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Transvaginal Drainage of Pelvic Abscesses and Collections Using Transabdominal Ultrasound Guidance.

PubMed

Ching, Kevin C; Sumkin, Jules H

2015-01-01

Objectives. To evaluate clinical outcomes following transvaginal catheter placement using transabdominal ultrasound guidance for management of pelvic fluid collections. Methods. A retrospective review was performed for all patients who underwent transvaginal catheter drainage of pelvic fluid collections utilizing transabdominal ultrasound guidance between July 2008 and July 2013. 24 consecutive patients were identified and 24 catheters were placed. Results. The mean age of patients was 48.1 years (range = 27-76 y). 88% of collections were postoperative (n = 21), 8% were from pelvic inflammatory disease (n = 2), and 4% were idiopathic (n = 1). Of the 24 patients, 83% of patients (n = 20) had previously undergone a hysterectomy and 1 patient (4%) was pregnant at the time of drainage. The mean volume of initial drainage was 108 mL (range = 5 to 570). Catheters were left in place for an average of 4.3 days (range = 1-17 d). Microbial sampling was performed in all patients with 71% (n = 17) returning a positive culture. All collections were successfully managed percutaneously. There were no technical complications. Conclusions. Transvaginal catheter drainage of pelvic fluid collections using transabdominal ultrasound guidance is a safe and clinically effective procedure. Appropriate percutaneous management can avoid the need for surgery.

Treatment of antimony mine drainage: challenges and opportunities with special emphasis on mineral adsorption and sulfate reducing bacteria.

PubMed

Li, Yongchao; Hu, Xiaoxian; Ren, Bozhi

2016-01-01

The present article summarizes antimony mine distribution, antimony mine drainage generation and environmental impacts, and critically analyses the remediation approach with special emphasis on iron oxidizing bacteria and sulfate reducing bacteria. Most recent research focuses on readily available low-cost adsorbents, such as minerals, wastes, and biosorbents. It is found that iron oxides prepared by chemical methods present superior adsorption ability for Sb(III) and Sb(V). However, this process is more costly and iron oxide activity can be inhibited by plenty of sulfate in antimony mine drainage. In the presence of sulfate reducing bacteria, sulfate can be reduced to sulfide and form Sb(2)S(3) precipitates. However, dissolved oxygen and lack of nutrient source in antimony mine drainage inhibit sulfate reducing bacteria activity. Biogenetic iron oxide minerals from iron corrosion by iron-oxidizing bacteria may prove promising for antimony adsorption, while the micro-environment generated from iron corrosion by iron oxidizing bacteria may provide better growth conditions for symbiotic sulfate reducing bacteria. Finally, based on biogenetic iron oxide adsorption and sulfate reducing bacteria followed by precipitation, the paper suggests an alternative treatment for antimony mine drainage that deserves exploration.

Emergency management of epidural haematoma through burr hole evacuation and drainage. A preliminary report.

PubMed

Liu, J T; Tyan, Y S; Lee, Y K; Wang, J T

2006-03-01

Blood clot evacuation through an osteoplastic craniotomy, a procedure requiring neurosurgical expertise and modern medical facilities, is the accepted method for treatment of a pure traumatic epidural haematoma following closed head injury. In certain emergency situations and/or in less sophisticated settings, however, use of this procedure may not be feasible. The present study was undertaken to ascertain whether placement of a burr hole and drainage under negative pressure constituted a rapid, effective and safe approach to manage patients with simple epidural haematomas. Thirteen patients suffering from a traumatic epidural haematoma were treated from January, 1999 to October, 2002. Twelve patients presented with skull fracture but no fracture was depressed. Placement of flexible tubes through a burr hole, followed by continuous suction under negative pressure, enabled aspiration of the clot and drainage of the cavity. In 8 cases, the procedure was performed under local anaesthesia with 2% Xylocaine and with intravenous sedation with propofol as needed. The operative procedure was accomplished within 30 min, and the drainage tube was left in place for 3-5 days. CT scans were performed daily from days 1 to 5. In 11 of 13 cases, clots were evacuated successfully and patients regained consciousness within 2 hours. Recoveries occurred without significant sequelae. In the remaining 2 cases, the drainage tube was found to be obstructed by a blood clot such that the haematoma was unaffected. A traditional craniotomy was performed within 8-12 hours, and these 2 patients recovered consciousness within the subsequent 6 hours. Burr hole evacuation followed by drainage under negative pressure is a safe and effective method for emergency management of a pure traumatic epidural haematoma. To assure safety patients given this procedure should be monitored by daily CT scans. Decompressive craniotomy should be performed if consciousness does not improve within several hours.

Multiphase flow predictions from carbonate pore space images using extracted network models

NASA Astrophysics Data System (ADS)

Al-Kharusi, Anwar S.; Blunt, Martin J.

2008-06-01

A methodology to extract networks from pore space images is used to make predictions of multiphase transport properties for subsurface carbonate samples. The extraction of the network model is based on the computation of the location and sizes of pores and throats to create a topological representation of the void space of three-dimensional (3-D) rock images, using the concept of maximal balls. In this work, we follow a multistaged workflow. We start with a 2-D thin-section image; convert it statistically into a 3-D representation of the pore space; extract a network model from this image; and finally, simulate primary drainage, waterflooding, and secondary drainage flow processes using a pore-scale simulator. We test this workflow for a reservoir carbonate rock. The network-predicted absolute permeability is similar to the core plug measured value and the value computed on the 3-D void space image using the lattice Boltzmann method. The predicted capillary pressure during primary drainage agrees well with a mercury-air experiment on a core sample, indicating that we have an adequate representation of the rock's pore structure. We adjust the contact angles in the network to match the measured waterflood and secondary drainage capillary pressures. We infer a significant degree of contact angle hysteresis. We then predict relative permeabilities for primary drainage, waterflooding, and secondary drainage that agree well with laboratory measured values. This approach can be used to predict multiphase transport properties when wettability and pore structure vary in a reservoir, where experimental data is scant or missing. There are shortfalls to this approach, however. We compare results from three networks, one of which was derived from a section of the rock containing vugs. Our method fails to predict properties reliably when an unrepresentative image is processed to construct the 3-D network model. This occurs when the image volume is not sufficient to represent the geological variations observed in a core plug sample.

The assessment of Urban Storm Inundation

NASA Astrophysics Data System (ADS)

Setyandito, Oki; Wijayanti, Yureana; Alwan, Muhammad; Chayati, Cholilul; Meilani

2017-12-01

A Sustainable and integrated plan in order to solve urban storm inundation problem, is an urgent issue in Indonesia. A reliable and complete datasets of urban storm inundation area in Indonesia should become its basis to give clear description of inundation area for formulating the best solution. In this study, Statistics Indonesia data in thirty three provinces were assessed during 2000 until 2012 providing data series of urban flood area, flood frequency and land cover changes. Drainage system condition in big cities should be well understood to ensure its infrastructure condition and performance. If inundation occurred, it can be concluded that there is drainage system problem. Inundation data is also important for drainage system design process in the future. The study result is provided estimation of urban storm inundation area based on calculation of Statistics Indonesia data. Moreover, this study is preceded by analyzing and reviewing the capacity of existing drainage channel, using case study of Mataram, West Nusa Tenggara. Rainfall data was obtained from three rainfall stations surround Mataram City. The storm water quantity was calculated using three different approaches as follows: 1) Rational Method; 2) Summation of existing inundation and surface run off discharge; 3) Discharge calculation from existing channel dimensions. After that, the result of these approaches was compared. The storm water quantity gap was concluded as quantity of inundation. The result shows that 36% of drainage channel in Brenyok Kanan River sub system could not accommodate the storm water runoff in this area, which causing inundation. The redesign of drainage channel using design discharge from Rational Method approach should be performed. Within area with the lowest level topography, a construction of detention or storage pond is essential to prevent inundation in this area. Furthermore, the benefits and drawbacks of the statistics database are discussed. Recommendations include utilizing more refined urban land use typologies that can better represent physical alteration of hydrological pathways

Transpedicular Curettage and Drainage of Infective Lumbar Spondylodiscitis: Technique and Clinical Results

PubMed Central

Lee, Byung Ho; Lee, Hwan-Mo; Kim, Tae-Hwan; Kim, Hak-Sun; Moon, Eun-Soo; Park, Jin-Oh; Chong, Hyun-Soo

2012-01-01

Background Infective spondylodiscitis usually occurs in patients of older age, immunocompromisation, co-morbidity, and individuals suffering from an overall poor general condition unable to undergo reconstructive anterior and posterior surgeries. Therefore, an alternative, less aggressive surgical method is needed for these select cases of infective spondylodiscitis. This retrospective clinical case series reports our novel surgical technique for the treatment of infective spondylodiscitis. Methods Between January 2005 and July 2011, among 48 patients who were diagnosed with pyogenic lumbar spondylodiscitis or tuberculosis lumbar spondylodiscitis, 10 patients (7 males and 3 females; 68 years and 48 to 78 years, respectively) underwent transpedicular curettage and drainage. The mean postoperative follow-up period was 29 months (range, 7 to 61 months). The pedicle screws were inserted to the adjacent healthy vertebrae in the usual manner. After insertion of pedicle screws, the drainage pedicle holes were made through pedicles of infected vertebra(e) in order to prevent possible seeding of infective emboli to the healthy vertebra, as the same instruments and utensils are used for both pedicle screws and the drainage holes. A minimum of 15,000 mL of sterilized normal saline was used for continuous irrigation through the pedicular pathways until the drained fluid looked clear. Results All patients' symptoms and inflammatory markers significantly improved clinically between postoperative 2 weeks and postoperative 3 months, and they were satisfied with their clinical results. Radiologically, all patients reached the spontaneous fusion between infected vertebrae and 3 patients had the screw pulled-out but they were clinically tolerable. Conclusions We suggest that our method of transpedicular curettage and drainage is a useful technique in regards to the treatment of infectious spondylodiscitic patients, who could not tolerate conventional combined anterior and posterior surgery due to multiple co-morbidities, multiple level infectious lesions and poor general condition. PMID:22949951

An improved analysis of gravity drainage experiments for estimating the unsaturated soil hydraulic functions

NASA Astrophysics Data System (ADS)

Sisson, James B.; van Genuchten, Martinus Th.

1991-04-01

The unsaturated hydraulic properties are important parameters in any quantitative description of water and solute transport in partially saturated soils. Currently, most in situ methods for estimating the unsaturated hydraulic conductivity (K) are based on analyses that require estimates of the soil water flux and the pressure head gradient. These analyses typically involve differencing of field-measured pressure head (h) and volumetric water content (θ) data, a process that can significantly amplify instrumental and measurement errors. More reliable methods result when differencing of field data can be avoided. One such method is based on estimates of the gravity drainage curve K'(θ) = dK/dθ which may be computed from observations of θ and/or h during the drainage phase of infiltration drainage experiments assuming unit gradient hydraulic conditions. The purpose of this study was to compare estimates of the unsaturated soil hydraulic functions on the basis of different combinations of field data θ, h, K, and K'. Five different data sets were used for the analysis: (1) θ-h, (2) K-θ, (3) K'-θ (4) K-θ-h, and (5) K'-θ-h. The analysis was applied to previously published data for the Norfolk, Troup, and Bethany soils. The K-θ-h and K'-θ-h data sets consistently produced nearly identical estimates of the hydraulic functions. The K-θ and K'-θ data also resulted in similar curves, although results in this case were less consistent than those produced by the K-θ-h and K'-θ-h data sets. We conclude from this study that differencing of field data can be avoided and hence that there is no need to calculate soil water fluxes and pressure head gradients from inherently noisy field-measured θ and h data. The gravity drainage analysis also provides results over a much broader range of hydraulic conductivity values than is possible with the more standard instantaneous profile analysis, especially when augmented with independently measured soil water retention data.

Continuous Passive Sampling of Solutes from Agricultural Subsurface Drainage Tubes

NASA Astrophysics Data System (ADS)

Lindblad Vendelboe, Anders; de Jonge, Hubert; Rozemeijer, Joachim; Wollesen de Jonge, Lis

2015-04-01

Agricultural subsurface tube drain systems play an important role in water and solute transport. One study, focusing on lowland agricultural catchments, showed that subsurface tube drainage contributed up to 80% of the annual discharge and 90% of the annual NO3 load from agricultural fields to the receiving water bodies. Knowledge of e.g. nutrient loads and drainage volumes, based on measurements and modelling, are important for adequate water quality management. Despite the importance of tube drain transport of solutes, monitoring data are scarce. This scarcity is a result of the existing monitoring techniques for flow and contaminant load from tube drains being expensive and labor-extensive. The study presented here aimed at developing a cheap, simple, and robust method to monitor solute loads from tube drains. The method is based on the newly developed Flowcap, which can be attached to existing tube drain outlets and can measure total flow, contaminant load and flow-averaged concentrations of solutes in the drainage. The Flowcap builds on the existing Sorbicell principle, a passive sampling system that measures average concentrations over longer periods of time (days to months) for various compounds. The Sorbicell consists of two compartments permeable to water. One compartment contains an adsorbent and one contains a tracer. When water passes through the Sorbicell the compound of interest is absorbed while a tracer is released. Using the tracer loss to calculate the volume of water that has passed the Sorbicell it is possible to calculate the average concentration of the compound. When mounting Sorbicells in the Flowcap, a flow-proportional part of the drainage is sampled from the main stream. To accommodate the wide range of drainage flow rates two Flowcaps with different capacities were tested in the laboratory: one with a capacity of 25 L min-1 (Q25) and one with a capacity of 256 L min-1 (Q256). In addition, Sorbicells with two different hydraulic resistances were tested, again to accommodate a large range of potential drainage flows rates. The experiment was continued until the Sorbicell's capacity was exhausted, which gave experimentation times from 6 to 34 days, while continuously changing the drainage flow rate to simulate field drainage conditions, and to test the range of the Flowcap. The laboratory testing yielded a very good linear correlation between drainage flow rates and Sorbicell sampling rates, giving r = 0.99 for both the Q25 and the Q256 Flowcap. The Sorbicells in this experiment were designed to measure NO3, but the Flowcap can be used with any Sorbicell and thus be used to measure any compound of interest. The Flowcap does not need housing, electricity, or maintenance and continuously register drainage volumes and contaminant loads for periods up to one month. This, in addition to the low cost of the monitoring system, enables large-scale monitoring of contaminant loads via tube drains, giving valuable data for the improvement of contaminant transport models. Further, these data will help select and evaluate the different mitigation option to improve water quality.

Geomorphic and Fish Genetics Constraints on Late Cenozoic Long Wavelength Topographic Evolution of the Hangay Mountains, Central Mongolia

NASA Astrophysics Data System (ADS)

Wegmann, K. W.; Tamra, M.; Sabaj Pérez, M.; Lopresti, M.; Cole, M. B.; Gosse, J. C.; Smith, S. G.; Bayasgalan, G.; Ancuta, L. D.; McDannell, K. T.; Gallen, S. F.

2014-12-01

The Hangay Mountains stand 1.5 - 2 km above adjacent lowlands and the timing and cause of their high elevation is debated. As part of a broad collaborative project, we synthesize several data sets that collectively suggest the Hangay increased in elevation during the mid-to-late Miocene, while topographic relief, one metric commonly associated with active mountain ranges, remained largely unchanged. The topographic crest of the Hangay forms the drainage divide between the Selenga River and internal drainage of the Mongolian Depression of Lakes (MDL) and northern Gobi. Synthetic drainage divides for the Hangay were created by filtering digital topography in the spectral domain (50 - 200 km wavelengths) using a 2D-FFT function. The co-location of the synthetic and modern divides suggests that the Hangay divide is in a stable, equilibrium configuration. This assumption is corroborated by chi-maps of steady-state river channel elevations that exhibit nearly equal values across water divides. An exception to both of these metrics occurs in the northwest Hangay where the Bulnay fault crosses a low divide between the western Selenga basin and the MDL. Recent basalt vesicle paleoaltimetry results allow for ~1 km of surface uplift of the central Hangay in the past ~ 10 Ma. These same basalt flows in-filled late Miocene valleys cut into basement with a minimum of 800 m of local relief; similar to the amount of modern, post-glacial relief along the drainage divide. mtDNA analyses from > 250 combined Stone Loaches (Barbatula), Grayling (Thymallus), and Eurasian Dace (Leuciscus) samples from both sides of the continental drainage divide are supportive of Miocene surface uplift. Molecular genetic differences between the loach populations across the divide suggest that they separated from a common ancestor between 20 and 11 Ma. This date is consistent with the timing of surface uplift and valley incision preserved in the Miocene basalt flows. The dace and grayling populations on either side of the divide separated more recently, at ~ 2 Ma and < 1 Ma, respectively. We speculate that either (1) Quaternary climate change via glacial drainage reorganization or (2) drainage capture in response to slip along the Bulnay fault forced these more recent separations. These topo-genetic constrains are needed inputs for regional geodynamic models.

The benefits of digital thoracic drainage system for outpatients undergoing pulmonary resection surgery.

PubMed

Mier, J M; Fibla, J J; Molins, L

2011-01-01

Since digital thoracic drainage system (DTDS) came onto the market, a number of its advantages have become clear, for example that of eliminating the differences between observers. The withdrawal of thoracic drainage has been found to be comfortable, safe and well tolerated by patients; it helps to reduce or eliminate the cost of hospital stay, because, according to the different series published in recent months, it is possible to withdraw drainage sooner and thus discharge patients earlier. Prospective studies are underway, but as yet nothing has been written about the possible benefits in outpatient surgery programmes. In this report we present our findings of 3 cases of patients undergoing pulmonary resection who were treated with continuous intra-domiciliary DTDS. Pending the results of a prospective study now underway our observation is that with properly selected patients this is a safe method. Copyright © 2010 Sociedade Portuguesa de Pneumologia. Published by Elsevier España. All rights reserved.

The dangers of long-term catheter drainage.

PubMed

Lowthian, P

There are many dangers associated with long-term urinary bladder drainage by catheter. For various reasons, the choice of catheter is important, and its initial insertion can be particularly hazardous. All catheterizations should, however, be safer when there is some urine (or other fluid) in the bladder. The appropriate choice of drainage system attached to the catheter can delay bacterial invasion of the bladder. Great care is needed to prevent blockage of the system, particularly when bacteriuria is present. Recent evidence indicates that some bacteria encourage the development of encrustations, so that, in some circumstances, catheters may become blocked within 24 hours. This, together with other considerations, strongly suggests that indwelling catheters should be changed at intervals of not more than 5 days. The practical implications of this are considered, as are the benefits that may accrue. Accidental catheter traction is another danger, and some possible methods of avoiding this are discussed. Finally, the need for a new kind of drainage-bag support is highlighted.

A simple method to treat post-kydney transplantation lymphocele.

PubMed

Damiano, G; Lombardo, C; Palumbo, V D; Buffa, D; Maione, C; Gioviale, M C; Cacciabaudo, F; Spinelli, G; Calvagna, C; Lo Monte, A I

2011-01-01

To describe our experience with ultrasonic-guided instillation of povidone-iodine to treat post-kidney transplantation lymphocele. Patients and methods. We studied the safety and efficacy of this procedure for treatment of lymphocele in 6 male kidney transplanted recipients in which we assisted a progressive increase of creatinine and urinary proteins levels and color-Doppler ultrasonography demonstrated an increase (25,4%) of index of resistence (IR) Using eco-colorDoppler, the related-graft lymphocele location and the distance to the anterior abdominal wall were determined; then, a radiopaque double-lumen catheter was used to instillate 5% povidone-iodine 10 ml. Results. Percutaneous drainage achieved a resolution rate of 100%. Studying the rate of peripheral and internal vascularization of the kidney before and after treatment, eco-colorDoppler showed a significant decrease of the IR (24,6%). Conclusions. The US-guided povidone-iodine instillation for treatment of lymphocele following renal transplantation may be considered as first choice therapy in such disease.

Methods for estimating low-flow statistics for Massachusetts streams

USGS Publications Warehouse

Ries, Kernell G.; Friesz, Paul J.

2000-01-01

Methods and computer software are described in this report for determining flow duration, low-flow frequency statistics, and August median flows. These low-flow statistics can be estimated for unregulated streams in Massachusetts using different methods depending on whether the location of interest is at a streamgaging station, a low-flow partial-record station, or an ungaged site where no data are available. Low-flow statistics for streamgaging stations can be estimated using standard U.S. Geological Survey methods described in the report. The MOVE.1 mathematical method and a graphical correlation method can be used to estimate low-flow statistics for low-flow partial-record stations. The MOVE.1 method is recommended when the relation between measured flows at a partial-record station and daily mean flows at a nearby, hydrologically similar streamgaging station is linear, and the graphical method is recommended when the relation is curved. Equations are presented for computing the variance and equivalent years of record for estimates of low-flow statistics for low-flow partial-record stations when either a single or multiple index stations are used to determine the estimates. The drainage-area ratio method or regression equations can be used to estimate low-flow statistics for ungaged sites where no data are available. The drainage-area ratio method is generally as accurate as or more accurate than regression estimates when the drainage-area ratio for an ungaged site is between 0.3 and 1.5 times the drainage area of the index data-collection site. Regression equations were developed to estimate the natural, long-term 99-, 98-, 95-, 90-, 85-, 80-, 75-, 70-, 60-, and 50-percent duration flows; the 7-day, 2-year and the 7-day, 10-year low flows; and the August median flow for ungaged sites in Massachusetts. Streamflow statistics and basin characteristics for 87 to 133 streamgaging stations and low-flow partial-record stations were used to develop the equations. The streamgaging stations had from 2 to 81 years of record, with a mean record length of 37 years. The low-flow partial-record stations had from 8 to 36 streamflow measurements, with a median of 14 measurements. All basin characteristics were determined from digital map data. The basin characteristics that were statistically significant in most of the final regression equations were drainage area, the area of stratified-drift deposits per unit of stream length plus 0.1, mean basin slope, and an indicator variable that was 0 in the eastern region and 1 in the western region of Massachusetts. The equations were developed by use of weighted-least-squares regression analyses, with weights assigned proportional to the years of record and inversely proportional to the variances of the streamflow statistics for the stations. Standard errors of prediction ranged from 70.7 to 17.5 percent for the equations to predict the 7-day, 10-year low flow and 50-percent duration flow, respectively. The equations are not applicable for use in the Southeast Coastal region of the State, or where basin characteristics for the selected ungaged site are outside the ranges of those for the stations used in the regression analyses. A World Wide Web application was developed that provides streamflow statistics for data collection stations from a data base and for ungaged sites by measuring the necessary basin characteristics for the site and solving the regression equations. Output provided by the Web application for ungaged sites includes a map of the drainage-basin boundary determined for the site, the measured basin characteristics, the estimated streamflow statistics, and 90-percent prediction intervals for the estimates. An equation is provided for combining regression and correlation estimates to obtain improved estimates of the streamflow statistics for low-flow partial-record stations. An equation is also provided for combining regression and drainage-area ratio estimates to obtain improved e

A multicomponent coupled model of glacier hydrology 1. Theory and synthetic examples

NASA Astrophysics Data System (ADS)

Flowers, Gwenn E.; Clarke, Garry K. C.

2002-11-01

Basal hydrology is acknowledged as a fundamental control on glacier dynamics, especially in cases where surface meltwater reaches the bed. For many glaciers at midlatitudes, basal drainage is influenced by subaerial, englacial, and subsurface water flow. One of the major shortcomings of existing basal hydrology models is the treatment of the glacier bed as an isolated system. We present theoretical and computational models that couple glacier surface runoff, englacial water storage and transport, subglacial drainage, and subsurface groundwater flow. Each of the four model components is represented as a two-dimensional, vertically integrated layer that communicates with its neighbors through water exchange. Governing equations are derived from the law of mass conservation and are expressed as a balance between the internal distribution of water and external sources. The numerical exposition of this theory is a time-dependent finite difference model that can be used to simulate glacier drainage. In this paper we outline the theory and conduct simple tests using an idealized glacier geometry. In the companion paper, the model is tailored to Trapridge Glacier, Yukon Territory, Canada, where results are compared with measurements of subglacial water pressure.

Experimental research on coalbed gas drainage effect and economy of long directional borehole in roof

NASA Astrophysics Data System (ADS)

Yang, Huiming; Hu, Liangping

2017-05-01

In order to study the coalbed gas drainage effect and economy of long directional roof borehole, 2 boreholes were laid out in Xinji No. 2 mine to analyze its gas drainage and investment costs comparing with high position roof borehole and high position roof roadway. The result indicates that the long directional roof borehole save investment by 44.8% and shorten the construction period by 30%, comparing with high position roof roadway for controlling gas in the working face. Investment slightly less and shorten the construction period by 47.5%, comparing with the roof high position borehole. Therefore, the method of the long directional roof borehole to drain coalbed gas in working face is the most cost-effective.

Great Basin cold desert shrublands and the Desert Experimental Range

Treesearch

Stanley G. Kitchen; Stephanie L. Carlson

2008-01-01

The Great Basin is a vast, internally drained region of the Western United States, bounded by the Sierra Nevada and southern Cascade Mountain ranges to the west and the Wasatch Mountains and western rim of the Colorado Plateau to the east. Although less discrete, northern and southern boundaries are generally defined by the drainages of the Columbia and Colorado Rivers...

An analytical study on groundwater flow in drainage basins with horizontal wells

NASA Astrophysics Data System (ADS)

Wang, Jun-Zhi; Jiang, Xiao-Wei; Wan, Li; Wang, Xu-Sheng; Li, Hailong

2014-06-01

Analytical studies on release/capture zones are often limited to a uniform background groundwater flow. In fact, for basin-scale problems, the undulating water table would lead to the development of hierarchically nested flow systems, which are more complex than a uniform flow. Under the premise that the water table is a replica of undulating topography and hardly influenced by wells, an analytical solution of hydraulic head is derived for a two-dimensional cross section of a drainage basin with horizontal injection/pumping wells. Based on the analytical solution, distributions of hydraulic head, stagnation points and flow systems (including release/capture zones) are explored. The superposition of injection/pumping wells onto the background flow field leads to the development of new internal stagnation points and new flow systems (including release/capture zones). Generally speaking, the existence of n injection/pumping wells would result in up to n new internal stagnation points and up to 2n new flow systems (including release/capture zones). The analytical study presented, which integrates traditional well hydraulics with the theory of regional groundwater flow, is useful in understanding basin-scale groundwater flow influenced by human activities.

Scrotal antegradesclerotherapy demonstrates anatomical variations on venous drainage in paediatric, adolescent and young adult varicoceles.

PubMed

Wong, Y S; Chung, K L Y; Lo, K W Y; Liu, C S W; Fan, T W; Tse, S K S; Tang, P M Y; Chao, N S Y; Liu, K K W; Leung, M W Y

2014-01-01

Anatomical variations on venous drainage in varicoceles are under-reported. We report our experience in scrotal antegrade sclerotherapy (SAS) for adolescent varicoceles. Since 2011, 15 consecutive boys with left varicoceles were recruited. Under general anaesthesia, a 5-mm transverse incision was made at scrotal neck, testicular vein was cannulated at pampiniform plexus with venogram performed. Foam sclerosant by mixing sodium tetradecyl sulphate (STS), Lipiodol(®) and air was slowly injected under fluoroscopy. Postoperatively the patients were followed-up for varicocele grading, testicular size, and complications. Median age at operation was 14 (10-19) years. 80 % had grade three varicoceles, 33.3 % had smaller left testis before operation. Intra-operative venogram showed three different anatomical variations. Group I: eleven patients (73.3 %) had single distinct internal spermatic vein; Group II: two patients demonstrated duplication of internal spermatic vein draining into left renal vein; Group III: two patients had pampiniform plexus draining to iliac and/or paraspinal veins. SAS was performed in Group I and II patients. Sclerosant volume injected ranged from 1.5 to 4.5 ml. In Group III patients, surgical ligation of testicular veins was performed rather than SAS to avoid uncontrolled systemic sclerosant spillage. Mean length of stay was 1.13 day. One patient with scrotal haematoma and one other with minor wound dehiscence were managed conservatively. Mean follow-up period was 10.9 (1-22) months. Thirteen patients (86.7 %) achieved varicocele grading ≤ 1. There was no postoperative testicular atrophy, hydrocele and epididymo-orchitis. Scrotal antegrade sclerotherapy using STS foam is a safe and effective treatment for adolescent varicoceles. Anatomical variations on venous drainage in varicoceles are common.

[Complex treatment of patients with cholangiogenic hepatic abscess].

PubMed

Nychytaĭlo, M Iu; Skums, A V; Medvets'kyĭ, Ie B; Ohorodnyk, P V; Mashkovs'kyĭ, H Iu; Shkarban, V P; Shkarban, P O; Farzolakh, Mekhraban Jafarlu

2005-07-01

Results of treatment of 47 patients with cholangiogenic hepatic abscess were analyzed. Clinical, laboratory and special methods of investigation were applied for diagnosis. The authors consider ultrasound investigation (USI), computer tomography and the abscess puncture under the USI control with subsequent cytological and bacterial control the decisive methods in diagnosis of hepatic abscess. In complex of treatment of patients miniinvasive technologies were applied--the abscess puncture, its cavity drainage under USI control transcutaneus transhepatic cholangiostomy, endoscopic papillosphincterotomy with lithotripsy and nasobiliary drainage, according to indications. Efficacy of the abscess cavity sanation, using miramistinum and decasan, was proved. In general therapy the directed transport of medicines was applied.

Estimating subcatchment runoff coefficients using weather radar and a downstream runoff sensor.

PubMed

Ahm, Malte; Thorndahl, Søren; Rasmussen, Michael R; Bassø, Lene

2013-01-01

This paper presents a method for estimating runoff coefficients of urban drainage subcatchments based on a combination of high resolution weather radar data and flow measurements from a downstream runoff sensor. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients of the separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678 ha) located in the city of Aarhus, Denmark. The study has proven that it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and downstream runoff measurements to identify the runoff coefficients at subcatchment level.

Combined Scleral Flap with Donor Scleral Patch Graft for Anterior Tube Placement in Glaucoma Drainage Device Surgery.

PubMed

Yu, Jea H; Nguyen, Chuck; Gallemore, Esmeralda; Gallemore, Ron P

2016-01-01

Purpose . To report a new technique for anterior placement of tubes for glaucoma drainage devices to reduce the risk of tube erosions. Methods . Retrospective review of select cases of Ahmed Valve surgery combined with the novel method of a limbal-based scleral flap covered by a scleral patch graft to cover the tube at the entrance through the limbus. Intraoperative and postoperative illustrations are shown to highlight the method of tube placement. Results . In this retrospective case series, 3 patients are presented illustrating the technique. Two had neovascular glaucoma and one had primary open-angle glaucoma (POAG). On average, intraocular pressure was reduced from 39 ± 14 mmHg to 15 ± 2 mmHg and the number of glaucoma medications was reduced from 4 ± 1 to 0. Preoperative and most recent visual acuities were hand-motion (HM) and HM, 20/60 and 20/50, and 20/70 and 20/30, respectively. Conclusion . The combination of a limbal-based scleral flap with scleral patch graft to cover the tube with glaucoma drainage devices may be an effective means to reduce erosion and protect against endophthalmitis.

Stream-channel and watershed delineations and basin-characteristic measurements using lidar elevation data for small drainage basins within the Des Moines Lobe landform region in Iowa

USGS Publications Warehouse

Eash, David A.; Barnes, Kimberlee K.; O'Shea, Padraic S.; Gelder, Brian K.

2018-02-14

Basin-characteristic measurements related to stream length, stream slope, stream density, and stream order have been identified as significant variables for estimation of flood, flow-duration, and low-flow discharges in Iowa. The placement of channel initiation points, however, has always been a matter of individual interpretation, leading to differences in stream definitions between analysts.This study investigated five different methods to define stream initiation using 3-meter light detection and ranging (lidar) digital elevation models (DEMs) data for 17 streamgages with drainage areas less than 50 square miles within the Des Moines Lobe landform region in north-central Iowa. Each DEM was hydrologically enforced and the five stream initiation methods were used to define channel initiation points and the downstream flow paths. The five different methods to define stream initiation were tested side-by-side for three watershed delineations: (1) the total drainage-area delineation, (2) an effective drainage-area delineation of basins based on a 2-percent annual exceedance probability (AEP) 12-hour rainfall, and (3) an effective drainage-area delineation based on a 20-percent AEP 12-hour rainfall.Generalized least squares regression analysis was used to develop a set of equations for sites in the Des Moines Lobe landform region for estimating discharges for ungaged stream sites with 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent AEPs. A total of 17 streamgages were included in the development of the regression equations. In addition, geographic information system software was used to measure 58 selected basin-characteristics for each streamgage.Results of the regression analyses of the 15 lidar datasets indicate that the datasets that produce regional regression equations (RREs) with the best overall predictive accuracy are the National Hydrographic Dataset, Iowa Department of Natural Resources, and profile curvature of 0.5 stream initiation methods combined with the 20-percent AEP 12-hour rainfall watershed delineation method. These RREs have a mean average standard error of prediction (SEP) for 4-, 2-, and 1-percent AEP discharges of 53.9 percent and a mean SEP for all eight AEPs of 55.5 percent. Compared to the RREs developed in this study using the basin characteristics from the U.S. Geological Survey StreamStats application, the lidar basin characteristics provide better overall predictive accuracy.

Method for estimating low-flow characteristics of ungaged streams in Indiana

USGS Publications Warehouse

Arihood, Leslie D.; Glatfelter, Dale R.

1991-01-01

Equations for estimating the 7-day, 2-year and 7oday, 10-year low flows at sites on ungaged streams are presented. Regression analysis was used to develop equations relating basin characteristics and low-flow characteristics at 82 gaging stations. Significant basin characteristics in the equations are contributing drainage area and flow-duration ratio, which is the 20-percent flow duration divided by the 90-percent flow duration. Flow-duration ratio has been regionalized for Indiana on a plate. Ratios for use in the equations are obtained from the plate. Drainage areas are determined from maps or are obtained from reports. The predictive capability of the method was determined by tests of the equations and of the flow-duration ratios on the plate. The accuracy of the equations alone was tested by estimating the low-flow characteristics at 82 gaging stations where flow-duration ratio is already known. In this case, the standard errors of estimate for 7-day, 2-year and 7-day, 10-year low flows are 19 and 28 percent. When flow-duration ratios for the 82 gaging stations are obtained from the map, the standard errors are 46 and 61 percent. However, when stations having drainage areas of less than 10 square miles are excluded from the test, the standard errors decrease to 38 and 49 percent. Standard errors increase when stations with small basins are included, probably because some of the flow-duration ratios obtained for these small basins are incorrect. Local geology and its effect on the ratio are not adequately reflected on the plate, which shows the regional variation in flow-duration ratio. In all the tests, no bias is apparent areally, with increasing drainage area or with increasing ratio. Guidelines and limitations should be considered when using the method. The method can be applied only at sites in the northern and central physiographic zones of the State. Low-flow characteristics cannot be estimated for regulated streams unless the amount of regulation is known so that the estimated low-flow characteristic can be adjusted. The method is most accurate for sites having drainage areas ranging from 10 to 1,000 square miles and for predictions of 7-day, 10-year low flows ranging from 0.5 to 340 cubic feet per second.

Method for estimating low-flow characteristics of ungaged streams in Indiana

USGS Publications Warehouse

Arihood, L.D.; Glatfelter, D.R.

1986-01-01

Equations for estimating the 7-day, 2-yr and 7-day, 10-yr low flows at sites on ungaged streams are presented. Regression analysis was used to develop equations relating basin characteristics and low flow characteristics at 82 gaging stations. Significant basin characteristics in the equations are contributing drainage area and flow duration ratio, which is the 20% flow duration divided by the 90% flow duration. Flow duration ratio has been regionalized for Indiana on a plate. Ratios for use in the equations are obtained from this plate. Drainage areas are determined from maps or are obtained from reports. The predictive capability of the method was determined by tests of the equations and of the flow duration ratios on the plate. The accuracy of the equations alone was tested by estimating the low flow characteristics at 82 gaging stations where flow duration ratio is already known. In this case, the standard errors of estimate for 7-day, 2-yr and 7-day, 10-yr low flows are 19% and 28%. When flow duration ratios for the 82 gaging stations are obtained from the map, the standard errors are 46% and 61%. However, when stations with drainage areas < 10 sq mi are excluded from the test, the standard errors reduce to 38% and 49%. Standard errors increase when stations with small basins are included, probably because some of the flow duration ratios obtained for these small basins are incorrect. Local geology and its effect on the ratio are not adequately reflected on the plate, which shows the regional variation in flow duration ratio. In all the tests, no bias is apparent areally, with increasing drainage area or with increasing ratio. Guidelines and limitations should be considered when using the method. The method can be applied only at sites in the northern and the central physiographic zones of the state. Low flow characteristics cannot be estimated for regulated streams unless the amount of regulation is known so that the estimated low flow characteristic can be adjusted. The method is most accurate for sites with drainage areas ranging from 10 to 1,000 sq mi and for predictions of 7-day, 10-yr low flows ranging from 0.5 to 340 cu ft/sec. (Author 's abstract)

Paravertebral Block: An Improved Method of Pain Control in Percutaneous Transhepatic Biliary Drainage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Culp, William C., E-mail: culpwilliamc@uams.edu; McCowan, Timothy C.; DeValdenebro, Miguel

Background and Purpose. Percutaneous transhepatic biliary drainage remains a painful procedure in many cases despite the routine use of large amounts of intravenous sedation. We present a feasibility study of thoracic paravertebral blocks in an effort to reduce pain during and following the procedure and reduce requirements for intravenous sedation. Methods. Ten consecutive patients undergoing biliary drainage procedures received fluoroscopically guided paravertebral blocks and then had supplemental intravenous sedation as required to maintain patient comfort. Levels T8-T9 and T9-T10 on the right were targeted with 10-20 ml of 0.5% bupivacaine. Sedation requirements and pain levels were recorded. Results. Ten biliarymore » drainage procedures in 8 patients were performed for malignancy in 8 cases and for stones in 2. The mean midazolam use was 1.13 mg IV, and the mean fentanyl requirement was 60.0 {mu}g IV in the block patients. Two episodes of hypotension, which responded promptly to volume replacement, may have been related to the block. No serious complications were encountered. The mean pain score when traversing the chest wall, liver capsule, and upon entering the bile ducts was 0.1 on a scale of 0 to 10, with 1 patient reporting a pain level of 1 and 9 reporting 0. The mean peak pain score, encountered when manipulating at the common bile duct level or when addressing stones there, was 5.4 and ranged from 0 to 10. Conclusions. Thoracic paravertebral block with intravenous sedation supplementation appears to be a feasible method of pain control during biliary interventions.« less

Twist-Drill or Burr Hole Craniostomy for Draining Chronic Subdural Hematomas: How to Choose It for Chronic Subdural Hematoma Drainage

PubMed Central

Lee, Seong-Jong; Im, Soo Bin

2016-01-01

Objective Although twist-drill craniostomy (TDC) has a number of procedural advantages and an equivalent outcome compared to burr hole craniostomy (BHC) for the treatment of chronic subdural hematomas (CSDHs), the latter technique remains the preferred method. We analyzed symptomatic CSDHs in whom TDC at the pre-coronal suture entry point (PCSEP) was the primary method for hematoma drainage and BHC on the parietal was the secondary option. Methods CSDHs in 86 consecutive patients were included. TDC at the PCSEP, which is 1 cm anterior to coronal suture at the level of the superior temporal line, was the primary operational technique when the hematoma thickness was suitable, and BHC was performed via the parietal when TDC was unreasonable or failed. The clinical feasibility and outcomes of these approaches were analyzed. Results Of the 86 patients, 68 (79.1%) were treated by TDC, and 18 (20.9%) by BHC. All patients showed improvements in their symptoms after hematoma drainage. Neither morbidity nor mortality was associated with either technique, and there were no differences in drainage days between the groups. Ten patients had bilateral hematomas and were treated using TDC. Two patients were not sufficiently treated by TDC and, as a result, BHC was applied. Only six hematomas (7% of 86 hematomas) exhibited insufficient thickness on the computed tomography to perform TDC. Conclusion When the hematoma was thick enough, a majority of the CSDHs were drained using TDC at the PCSEP as the first procedure, which was especially useful for bilateral hematomas and in elderly patients. PMID:27857917

A closed system irrigation & drainage technique for surgical evacuation of chronic subdural haematomas

PubMed Central

Kareem, Haider; Adams, Hadie

2018-01-01

Background: Chronic subdural haematoma (CSDH), is a common neurosurgical disorder that is associated with morbidity and mortality affecting the ageing population. The aim is to present the treatment experience of CSDH patients treated with a technique that combines the classical single burr-hole irrigation and the continuous closed system drainage: The closed system irrigation & drainage (CSID) technique. Methods: The cases undergoing CSDH evacuation with the CSID method were captured over a 4-year period at a tertiary neurosurgical centre. The authors describe the performance of this methods with respect to post-operative clinical and radiological features, including recurrence rates, complications, and length of stay. Results: A total of 36 cases undergoing 42 CSID procedures (30 unilateral and 6 bilateral CSDHs) were performed, in cases ranging between 55-95 years old (median age 79 years). The rate of recurrence or significant ruminant blood in the subdural space on post-operative imaging was 11% (n=4). No cases of pneumocephalus were observed in this series (n=0). The mean (SD) skin-to-skin time for this procedure was 13.4 (4.4) minutes, with a mean (SD) length of stay of 4 (1.9) days. Conclusion: We conclude that the one burr-hole closed system irrigation and drainage technique with a sub-periosteal drain seems to be a simple, effective and safe procedure for treatment of CSDH. It’s well tolerated under local anaesthesia for patients with high co-morbidities and these preliminary results indicated it may potentially be a better option for treatment of CSDH with a lower rate of post-operative complications. PMID:29904602

Quantitative analysis and implications of drainage morphometry of the Agula watershed in the semi-arid northern Ethiopia

NASA Astrophysics Data System (ADS)

Fenta, Ayele Almaw; Yasuda, Hiroshi; Shimizu, Katsuyuki; Haregeweyn, Nigussie; Woldearegay, Kifle

2017-11-01

This study aimed at quantitative analysis of morphometric parameters of Agula watershed and its sub-watersheds using remote sensing data, geographic information system, and statistical methods. Morphometric parameters were evaluated from four perspectives: drainage network, watershed geometry, drainage texture, and relief characteristics. A sixth-order river drains Agula watershed and the drainage network is mainly dendritic type. The mean bifurcation ratio ( R b) was 4.46 and at sub-watershed scale, high R b values ( R b > 5) were observed which might be expected in regions of steeply sloping terrain. The longest flow path of Agula watershed is 48.5 km, with knickpoints along the main river which could be attributed to change of lithology and major faults which are common along the rift escarpments. The watershed has elongated shape suggesting low peak flows for longer duration and hence easier flood management. The drainage texture analysis revealed fine drainage which implies the dominance of impermeable soft rock with low resistance against erosion. High relief and steep slopes dominates, by which rough landforms (hills, breaks, and low mountains) make up 76% of the watershed. The S-shaped hypsometric curve with hypsometric integral of 0.4 suggests that Agula watershed is in equilibrium or mature stage of geomorphic evolution. At sub-watershed scale, the derived morphometric parameters were grouped into three clusters (low, moderate, and high) and considerable spatial variability was observed. The results of this study provide information on drainage morphometry that can help better understand the watershed characteristics and serve as a basis for improved planning, management, and decision making to ensure sustainable use of watershed resources.

The efficacy and safety of burr-hole craniotomy without continuous drainage for chronic subdural hematoma and subdural hygroma in children under 2 years of age.

PubMed

Matsuo, Kazuya; Akutsu, Nobuyuki; Otsuka, Kunitoshi; Yamamoto, Kazuki; Kawamura, Atsufumi; Nagashima, Tatsuya

2016-12-01

Various treatment modalities have been used in the management of chronic subdural hematoma and subdural hygroma (CSDH/SDHy) in children. However, few studies have examined burr-hole craniotomy without continuous drainage in such cases. Here, we retrospectively evaluated the efficacy and safety of burr-hole craniotomy without continuous drainage for CSDH/SDHy in children under 2 years old. We also aimed to determine the predictors of CSDH/SDHy recurrence. We conducted a retrospective chart review of 25 children under 2 years old who underwent burr-hole craniotomy without continuous drainage for CSDH/SDHy at a pediatric teaching hospital over a 10-year period. We analyzed the relationship between CSDH/SDHy recurrence and factors such as abusive head trauma, laterality of CSDH/SDHy, and subdural fluid collection type (hematoma or hygroma). CSDH/SDHy recurred in 5 of the 25 patients (20 %), requiring a second operation at an average of 0.92 ± 1.12 months after the initial procedure. The mean follow-up period was 25.1 ± 28.6 months. There were no complications related to either operation. None of the assessed factors were statistically associated with recurrence. Burr-hole craniotomy without continuous drainage for CSDH/SDHy appears safe in children aged under 2 years and results in a relatively low recurrence rate. No predictors of CSDH/SDHy recurrence were identified. Advantages of this method include avoiding external subdural drainage-related complications. However, burr-hole drainage may be more effective for CSDH, which our data suggests is more likely to recur than SDHy, providing the procedure is performed with specific efforts to reduce complications.

Modelling the ability of source control measures to reduce inundation risk in a community-scale urban drainage system

NASA Astrophysics Data System (ADS)

Mei, Chao; Liu, Jiahong; Wang, Hao; Shao, Weiwei; Xia, Lin; Xiang, Chenyao; Zhou, Jinjun

2018-06-01

Urban inundation is a serious challenge that increasingly confronts the residents of many cities, as well as policymakers, in the context of rapid urbanization and climate change worldwide. In recent years, source control measures (SCMs) such as green roofs, permeable pavements, rain gardens, and vegetative swales have been implemented to address flood inundation in urban settings, and proven to be cost-effective and sustainable. In order to investigate the ability of SCMs on reducing inundation in a community-scale urban drainage system, a dynamic rainfall-runoff model of a community-scale urban drainage system was developed based on SWMM. SCMs implementing scenarios were modelled under six design rainstorm events with return period ranging from 2 to 100 years, and inundation risks of the drainage system were evaluated before and after the proposed implementation of SCMs, with a risk-evaluation method based on SWMM and analytic hierarchy process (AHP). Results show that, SCMs implementation resulting in significantly reduction of hydrological indexes that related to inundation risks, range of reduction rates of average flow, peak flow, and total flooded volume of the drainage system were 28.1-72.1, 19.0-69.2, and 33.9-56.0 %, respectively, under six rainfall events with return periods ranging from 2 to 100 years. Corresponding, the inundation risks of the drainage system were significantly reduced after SCMs implementation, the risk values falling below 0.2 when the rainfall return period was less than 10 years. Simulation results confirm the effectiveness of SCMs on mitigating inundation, and quantified the potential of SCMs on reducing inundation risks in the urban drainage system, which provided scientific references for implementing SCMs for inundation control of the study area.

Primary closure versus T-tube drainage in laparoscopic common bile duct exploration: a meta-analysis of randomized clinical trials.

PubMed

Wu, Xiangsong; Yang, Yong; Dong, Ping; Gu, Jun; Lu, Jianhua; Li, Maolan; Mu, Jiasheng; Wu, Wenguang; Yang, Jiahua; Zhang, Lin; Ding, Qichen; Liu, Yingbin

2012-08-01

To compare the safety and effectiveness of primary closure with those of T-tube drainage in laparoscopic common bile duct exploration (LCBDE) for choledocholithiasis. A comprehensive search was performed in the PubMed, EmBase, and Cochrane Library databases. Only randomized controlled trials comparing primary closure with T-tube drainage in LCBDE were considered eligible for this meta-analysis. The analyzed outcome variables included postoperative mortality, overall morbidity, biliary complication rate, biliary leak rate, reoperation, operating time, postoperative hospital stay, time to abdominal drain removal, and retained stone. All calculations and statistical tests were performed using ReviewerManager 5.1.2 software. A total of 295 patients (148 patients with primary closure and 147 patients with T-tube drainage) from three trials were identified and analyzed. No deaths occurred in any of the trials. Primary closure showed significantly better results in terms of morbidity (risk ratio (RR), 0.51; 95% confidence interval (CI), 0.30 to 0.88), biliary complication without a combination of retained stone (RR, 0.44; 95% CI, 0.20 to 0.97), reoperation (RR, 0.16; 95% CI, 0.03 to 0.87), operating time (mean difference (MD), -20.72; 95% CI, -29.59 to -11.85), postoperative hospital stay (MD, -3.24; 95% CI, -3.96 to -2.52), and time to abdominal drainage removal (MD, -0.45; 95% CI, -0.86 to -0.04). Statistically significant differences were not found between the two methods in terms of biliary leak, biliary complication, and retained stones. The current meta-analysis indicates that primary closure of the common bile duct is safer and more effective than T-tube drainage for LCBDE. Therefore, we do not recommend routine performance of T-tube drainage in LCBDE.

Management of traumatic hemothorax by closed thoracic drainage using a central venous catheter

PubMed Central

Yi, Jian-hua; Liu, Hua-bo; Zhang, Mao; Wu, Jun-song; Yang, Jian-xin; Chen, Jin-ming; Xu, Shan-xiang; Wang, Jian-an

2012-01-01

Objective: To evaluate the efficacy and safety of the treatment of traumatic hemothorax by closed pleural drainage using a central venous catheter (CVC), compared with using a conventional chest tube. Methods: A prospective controlled study with the Ethics Committee approval was undertaken. A total of 407 patients with traumatic hemothorax were involved and they were randomly assigned to undergo closed pleural drainage with CVCs (n=214) or conventional chest tubes (n=193). The Seldinger technique was used for drainage by CVC, and the conventional technique for drainage by chest tube. If the residual volume of the hemothorax was less than 200 ml after the daily volume of drainage decreased to below 100 ml for two consecutive days, the treatment was considered successful. The correlative data of efficacy and safety between the two groups were analyzed using t or chi-squared tests with SPSS 13.0. A P value of less than 0.05 was taken as indicating statistical significance. Results: Compared with the chest tube group, the operation time, fraction of analgesic treatment, time of surgical wound healing, and infection rate of surgical wounds were significantly decreased (P<0.05) in the CVC group. There were no significant differences between the two groups in the success rate of treatment and the incidence of serious complications (P>0.05), or in the mean catheter/tube indwelling time and mean medical costs of patients treated successfully (P>0.05). Conclusions: Management of medium or large traumatic hemothoraxes by closed thoracic drainage using CVC is minimally invasive and as effective as using a conventional large-bore chest tube. Its complications can be prevented and it has the potential to replace the large-bore chest tube. PMID:22205619

Regional Hydraulic Geometry Curves of the Northern Cascade Mountains, Chelan and King Counties, Washington State, USA

NASA Astrophysics Data System (ADS)

Gasperi, J. T.; McClung, J. M.; Hanson, D. L.

2006-12-01

The USDA-Natural Resources Conservation Service has developed regional hydraulic geometry curves relating drainage area to bankfull top width, mean depth and cross-sectional area for the east and west sides of the northern Cascade Mountains in Chelan and King Counties, Washington. NRCS surveyed 10 channel reaches with drainage areas from 1 to 1000 square miles within the Wenatchee River drainage of Chelan County and 10 channel reaches with drainage areas of 1 to 100 square miles within the Cedar and Green River drainages of King County. Selection criteria for stream reaches required a minimum of 20 years of USGS stream gage discharge records, unregulated flows and safe access. Survey data were collected with a Sokkia Total Station during low flow conditions from August 2004 to September 2005. NRCS measured a channel cross-section at each of the USGS stream gage sites and two or three additional cross-sections up and downstream. The authors also collected samples of bed material for gradation analysis and estimation of Manning's roughness coefficient, n. Bankfull elevations were estimated based on visual identification of field indicators and USGS flood discharges for the 50% exceedance probability event. Field data were evaluated with the Ohio DNR Reference Reach spreadsheet to determine bankfull top width, mean depth and cross-sectional area. We applied a simple linear regression to the data following USGS statistical methods to evaluate the closeness of fit between drainage area and bankfull channel dimensions. The resulting R2 values of 0.83 to 0.93 for the eastern Cascade data of Chelan County and 0.71 to 0.88 for the western Cascade data of King County indicate a close association between drainage area and bankfull channel dimensions for these two sets of data.

Applications of network analysis for adaptive management of artificial drainage systems in landscapes vulnerable to sea level rise

NASA Astrophysics Data System (ADS)

Poulter, Benjamin; Goodall, Jonathan L.; Halpin, Patrick N.

2008-08-01

SummaryThe vulnerability of coastal landscapes to sea level rise is compounded by the existence of extensive artificial drainage networks initially built to lower water tables for agriculture, forestry, and human settlements. These drainage networks are found in landscapes with little topographic relief where channel flow is characterized by bi-directional movement across multiple time-scales and related to precipitation, wind, and tidal patterns. The current configuration of many artificial drainage networks exacerbates impacts associated with sea level rise such as salt-intrusion and increased flooding. This suggests that in the short-term, drainage networks might be managed to mitigate sea level rise related impacts. The challenge, however, is that hydrologic processes in regions where channel flow direction is weakly related to slope and topography require extensive parameterization for numerical models which is limited where network size is on the order of a hundred or more kilometers in total length. Here we present an application of graph theoretic algorithms to efficiently investigate network properties relevant to the management of a large artificial drainage system in coastal North Carolina, USA. We created a digital network model representing the observation network topology and four types of drainage features (canal, collector and field ditches, and streams). We applied betweenness-centrality concepts (using Dijkstra's shortest path algorithm) to determine major hydrologic flowpaths based off of hydraulic resistance. Following this, we identified sub-networks that could be managed independently using a community structure and modularity approach. Lastly, a betweenness-centrality algorithm was applied to identify major shoreline entry points to the network that disproportionately control water movement in and out of the network. We demonstrate that graph theory can be applied to solving management and monitoring problems associated with sea level rise for poorly understood drainage networks in advance of numerical methods.

Diuretic 99mTc DTPA renography in assessment of renal function and drainage in infants with antenatally detected hydronephrosis.

PubMed

Radulović, Marija; Pucar, Dragan; Jauković, Ljiljana; Sisić, Marija; Krstić, Zoran; Ajdinović, Boris

2015-12-01

The controversy over the postnatal management of infants with antenataly detected hydronephrosis (ANH) still exists. We presented the results of diuretic 99mTc diethylenetriamine pentaacetic acid (DTPA) renography in 30 infants with the antenatal diagnosis of unilateral renal pelvic dilatation. The aim of this study was to assess the renal function determined by the pattern of drainage and split renal function (SRF) on diuretic renography and to correlate these findings with anteroposterior pelvic diameter (APD) estimated by ultrasonography. A total of 30 infants with 60 renal units (RU) (25 boys and 5 girls, median age 6.0 months, range 2-24) presented with unilateral hydronephrosis on ultrasound in the newborn period, underwent DTPA diuretic renal scintigraphy (F+15 protocol). The median APD evaluated on perinatal ultrasound was 15 mm (range 5-30). The postnatal associated clinical diagnosis were pelviureteric junction obstruction (PUJ), simple hydronephrosis, megaureter, vesicoureteral reflux (VUR) and posterior urethral valves in 11, 10, 6, 2 and 1 infant, respectively. Images and Tmax/2 after diuretic stimulation on the background subtracted renographic curves were used as the criteria for classifying the drainage as good, partial, and poor or no drainage. The SRF was calculated with the integral method. Good drainage was shown in 36/60, partial drainage in 13/60 and poor or no drainage in 11/60 RU. The SRF > 40% was observed in 55/60 RU, with no RU showing SRF lower than 23.5%. In infants with severe ANH the obstruction was not excluded in 94.1%. Diuretic renography in antenatally detected hydronephrosis should be a useful tool in postnatal follow up, especially in differentiating nonobstructive hydronephrosis from obstructive. It is also importanat to assess and monitor the SRF. Our results suggest that even in the presence of partial or no drainage, SRF may not be significantly impaired.

Time to Redefine the Intramammary Lymph Node as a Separate Entity?

PubMed

Green, M; Tafazal, H; Swati, B; Vidya, R

2018-04-17

The lymphatic drainage for the majority of primary breast tumours is to the axillary lymph nodes (ALNs). Some, however drain to the so-called extra-axillary basins, namely the internal mammary, supra- and infraclavicular regions. Another potential drainage route includes the intramammary lymph nodes (IMLNs). Current guidance suggests IMLNs should be considered as part of the axillary group, potentially affecting axillary management. However, due to evolution in imaging and advancement in technology, IMLNs may now be distinguished more accurately pre-operatively. There are currently no published guidelines for the management of IMLNs in the United Kingdom. The authors suggest that it is time to reclassify IMLNs as a separate focus of cancer and treat it as a separate entity. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

Comparison of three surgical treatment options for unicameral bone cysts in humerus.

PubMed

Mavčič, Blaž; Saraph, Vinay; Gilg, Magdalena M; Bergovec, Marko; Brecelj, Janez; Leithner, Andreas

2018-04-23

Treatment of unicameral bone cysts (UBC) in the humerus with drainage screws is scarcely reported in the literature. The aim of this retrospective study was to compare drainage screws and alternative treatment methods with respect to the number of required surgical procedures to achieve sufficient UBC healing, postoperative fractures/recurrences/complications, and radiological outcome. Medical archives of two tertiary orthopedic referral centers were screened for all patients who were treated surgically for humeral UBC in the period 1991-2015 with a histologically/cytologically confirmed diagnosis. Sex, age, all surgical procedures, fractures, complications, recurrences, and the final radiological outcome were compared between patients treated with drainage screws, elastic intramedullary nails, or curettage with optional grafting. The study included 106 operated patients with a mean age of 10.3 years, with a mean follow-up of 5.7 years. The average number of UBC-related surgical procedures in sex-matched and age-matched treatment groups was 2.7 with drainage screws, 2.8 with intramedullary nails, and 3.5 with curettage/grafting (P=0.54). Intramedullary nails (odds ratio 0.20) and older age (odds ratio for each year 0.83) predicted a lower risk of postoperative UBC recurrence. Patients with drainage screws had the highest UBC recurrence rates and the lowest rates of changed initial treatment method. There was no difference between the treatment groups in the postoperative fracture rate, complications, or the final radiological outcome. UBC treatment in the humerus therefore requires approximately three surgical procedures, irrespective of the treatment modality chosen. Adding an elastic intramedullary nail to a humeral UBC cyst may reduce recurrence risk and prevent further fractures. Level III - therapeutic retrospective comparative study.

Accurate seismic phase identification and arrival time picking of glacial icequakes

NASA Astrophysics Data System (ADS)

Jones, G. A.; Doyle, S. H.; Dow, C.; Kulessa, B.; Hubbard, A.

2010-12-01

A catastrophic lake drainage event was monitored continuously using an array of 6, 4.5 Hz 3 component geophones in the Russell Glacier catchment, Western Greenland. Many thousands of events and arrival time phases (e.g., P- or S-wave) were recorded, often with events occurring simultaneously but at different locations. In addition, different styles of seismic events were identified from 'classical' tectonic earthquakes to tremors usually observed in volcanic regions. The presence of such a diverse and large dataset provides insight into the complex system of lake drainage. One of the most fundamental steps in seismology is the accurate identification of a seismic event and its associated arrival times. However, the collection of such a large and complex dataset makes the manual identification of a seismic event and picking of the arrival time phases time consuming with variable results. To overcome the issues of consistency and manpower, a number of different methods have been developed including short-term and long-term averages, spectrograms, wavelets, polarisation analyses, higher order statistics and auto-regressive techniques. Here we propose an automated procedure which establishes the phase type and accurately determines the arrival times. The procedure combines a number of different automated methods to achieve this, and is applied to the recently acquired lake drainage data. Accurate identification of events and their arrival time phases are the first steps in gaining a greater understanding of the extent of the deformation and the mechanism of such drainage events. A good knowledge of the propagation pathway of lake drainage meltwater through a glacier will have significant consequences for interpretation of glacial and ice sheet dynamics.

A method for early diagnosis and treatment of intrathoracic esophageal anastomotic leakage: prophylactic placement of a drainage tube adjacent to the anastomosis.

PubMed

Tang, Hua; Xue, Lei; Hong, Jiang; Tao, Xiandong; Xu, Zhifei; Wu, Bin

2012-04-01

Anastomotic leakage is a severe complication after esophagectomy, which results in high mortality and morbidity. In this study, we will preset a drainage tube adjacent to the anastomosis and evaluate its effect in the diagnosis and treatment of anastomotic leakage. We undertook a retrospective review of 414 patients who underwent partial esophageal resection or cardia resection with intrathoracic esophagogastric anastomosis. The patients were divided into two groups (Tube group and no-tube group) according to whether a drainage tube was placed adjacent to the anastomotic stoma during the surgical procedure. The leakage rate, time to diagnosis, time to flush, time to recovery, and patient outcome were analyzed. The leakage rate in the tube group was 5.35% (6/112) while it was 3.64% (11/302) in the no-tube group. The total mortality among patients with anastomotic leakage was 29.41%. In the tube group, all the patients were definitively diagnosed the same day on which suspicion of leakage occurs while the patients in the no-tube group required further examination to diagnose. In the no-tube group, the patients required placement of a drainage tube with the help of computed tomography or ultrasonic examination while there was no need for further procedures in the tube group. The days to flush and recovery in the tube group were 23.4 ± 5.94 and 32.2 ± 10.84, respectively, while, in the no-tube group, it was 80.71 ± 48.41 and 98.14 ± 56.24 (P < 0.05). In conclusion, prophylactic implantation of a drainage tube adjacent to the esophageal anastomosis is a good method for rapid diagnosis and treatment of leakage.

Application of Spatial Neural Network Model for Optimal Operation of Urban Drainage System

NASA Astrophysics Data System (ADS)

KIM, B. J.; Lee, J. Y.; KIM, H. I.; Son, A. L.; Han, K. Y.

2017-12-01

The significance of real-time operation of drainage pump and warning system for inundation becomes recently increased in order to coping with runoff by high intensity precipitation such as localized heavy rain that frequently and suddenly happen. However existing operation of drainage pump station has been made a decision according to opinion of manager based on stage because of not expecting exact time that peak discharge occur in pump station. Therefore the scale of pump station has been excessively estimated. Although it is necessary to perform quick and accurate inundation in analysis downtown area due to huge property damage from flood and typhoon, previous studies contained risk deducting incorrect result that differs from actual result owing to the diffusion aspect of flow by effect on building and road. The purpose of this study is to develop the data driven model for the real-time operation of drainage pump station and two-dimensional inundation analysis that are improved the problems of the existing hydrology and hydrological model. Neuro-Fuzzy system for real time prediction about stage was developed by estimating the type and number of membership function. Based on forecasting stage, it was decided when pump machine begin to work and how much water scoop up by using penalizing genetic algorithm. It is practicable to forecast stage, optimize pump operation and simulate inundation analysis in real time through the methodologies suggested in this study. This study can greatly contribute to the establishment of disaster information map that prevent and mitigate inundation in urban drainage area. The applicability of the development model for the five drainage pump stations in the Mapo drainage area was verified. It is considered to be able to effectively manage urban drainage facilities in the development of these operating rules. Keywords : Urban flooding; Geo-ANFIS method; Optimal operation; Drainage system; AcknowlegementThis research was supported by a grant (17AWMP-B079625-04) from Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Infeasibility of endoscopic transmural drainage due to pancreatic pseudocyst wall calcifications - case report.

PubMed

Krajewski, Andrzej; Lech, Gustaw; Makiewicz, Marcin; Kluciński, Andrzej; Wojtasik, Monika; Kozieł, Sławomir; Słodkowski, Maciej

2017-02-28

Postinflammatory pancreatic pseudocysts are one of the most common complications of acute pancreatitis. In most cases, pseudocysts self-absorb in the course of treatment of pancreatitis. In some patients, pancreatic pseudocysts are symptomatic and cause pain, problems with gastrointestinal transit, and other complications. In such cases, drainage or resection should be performed. Among the invasive methods, mini invasive procedures like endoscopic transmural drainage through the wall of the stomach or duodenum play an important role. For endoscopic transmural drainage, it is necessary that the cyst wall adheres to the stomach or duodenum, making a visible impression. We present a very rare case of infeasibility of endoscopic drainage of a postinflammatory pancreatic pseudocyst, impressing the stomach, due to cyst wall calcifications. A 55-year-old man after acute pancreatitis presented with a 1-year history of epigastric pain and was admitted due to a postinflammatory pseudocyst in the body and tail of pancreas. On admission, blood tests, including CA 19-9 and CEA, were normal. An ultrasound examination revealed a 100-mm pseudocyst in the tail of pancreas, which was confirmed on CT and EUS. Acoustic shadowing caused by cyst wall calcifications made the cyst unavailable to ultrasound assessment and percutaneous drainage. Gastroscopy revealed an impression on the stomach wall from the outside. The patient was scheduled for endoscopic transmural drainage. After insufflation of the stomach, a large mass protruding from the wall was observed. The stomach mucosa was punctured with a cystotome needle knife, and the pancreatic cyst wall was reached. Due to cyst wall calcifications, endoscopic drainage of the cyst was unfeasible. Profuse submucosal bleeding at the puncture site was stopped by placing clips. The patient was scheduled for open surgery, and distal pancreatectomy with splenectomy was performed. The histopathological examination confirmed the initial diagnosis of postinflammatory pancreatic pseudocyst. Endoscopic transmural drainage is a highly effective procedure for treating postinflammatory pancreatic pseudocysts. In some patents, especially with large pseudocysts, pseudocysts with calcified walls, and cysts of primary origin, resection should be performed.

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

PubMed Central

Choi, Jin Woo; Kim, Kyoung Won; Kim, Ah Young; Kim, Pyo Nyun; Ha, Hyun Kwon; Lee, Moon-Gyu

2003-01-01

Objective To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation. Materials and Methods The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct. Results The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3). Conclusion The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%). PMID:12845303

Comparison of pigtail catheter with chest tube for drainage of parapneumonic effusion in children.

PubMed

Lin, Chien-Heng; Lin, Wei-Ching; Chang, Jeng-Sheng

2011-12-01

The use of thoracostomy tube for drainage of parapneumonic effusion is an important therapeutic measure. In this study, we compared the effectiveness and complications between chest tube and pigtail catheter thoracostomy for drainage of parapneumonic pleural effusion in children. We retrospectively reviewed the medical records of children with parapneumonic effusion during the period of July 2001 through December 2003. Patients who received thoracostomy with either chest tube or pigtail catheter were enrolled into this study. Medical records, such as age, sex, clinical presentation, subsequent therapies, hospital stay, laboratory data, and complications, were collected and compared between these two methods of intervention. A total of 32 patients (17 boys and 15 girls; age range, 2-17 years; mean age, 14 years) were enrolled into the study. Twenty patients were treated with traditional chest tubes, whereas 12 patients were treated with pigtail catheters. In the chest tube group, drainage failure occurred in one patient and pneumothorax occurred in two patients. In the pigtail catheter group, drainage failure occurred in two patients, but no case was complicated with pneumothorax. There were no significant differences in either drainage days or hospitalization days between the chest tube group and pigtail catheter group (6.0 ± 2.6 vs. 5.9 ± 3.8, p=0.66; 12.5 ± 5.6 vs. 17.3 ± 8.5, p=0.13). The effectiveness and complications of the pigtail catheter were comparable to those of the chest tubes. Copyright © 2011. Published by Elsevier B.V.

Moisture Separator Reheater for NPP Turbines

NASA Astrophysics Data System (ADS)

Manabe, Jun; Kasahara, Jiro

This paper introduces the development of the current model Moisture Separator Reheater (MSR) for nuclear power plant (NPP) turbines, commercially placed in service in the period 1984-1997, focusing on the mist separation performance of the MSR along with drainage from heat exchanger tubes. A method of predicting the mist separation performance was devised first based on the observation of mist separation behaviors under an air-water test. Then the method was developed for the application to predict under the steam conditions, followed by the verification in comparison with the actual results of a steam condition test. The instability of tube drainage associated with both sub-cooling and temperature oscillation might adversely affect the seal welding of tubes to tube sheet due to thermal fatigue. The instability was measured on an existing unit to clarify behaviors and the development of a method to suppress them. Both methods were applied to newly constructed units and the effectiveness of the methods was demonstrated.

The co-genetic evolution of metamorphic core complexes and drainage systems

NASA Astrophysics Data System (ADS)

Trost, Georg; Neubauer, Franz; Robl, Jörg

2016-04-01

Metamorphic core complexes (MCCs) are large scale geological features that globally occur in high strain zones where rocks from lower crustal levels are rapidly exhumed along discrete fault zones, basically ductile-low-angle normal faults recognizable by a metamorphic break between the cool upper plate and hot lower plate. Standard methods, structural analysis and geochronology, are applied to reveal the geodynamic setting of MCCs and to constrain timing and rates of their exhumation. Exhumation is abundantly accompanied by spatially and temporally variable vertical (uplift) and horizontal motions (lateral advection) representing the tectonic driver of topography formation that forces drainage systems and related hillslopes to adjust. The drainage pattern commonly develops in the final stage of exhumation and contributes to the decay of the forming topography. Astonishingly, drainage systems and their characteristic metrics (e.g. normalized steepness index) in regions coined by MCCs have only been sparsely investigated to determine distinctions between different MCC-types (A- and B-type MCCs according to Le Pourhiet et al., 2012). They however, should significantly differ in their topographic expression that evolves by the interplay of tectonic forcing and erosional surface processes. A-type MCCs develop in an overall extensional regime and are bounded partly by strike-slip faults showing transtensional or transpressional components. B-type MCCs are influenced by extensional dynamics only. Here, we introduce C-type MCCs that are updoming along oversteps of crustal-scale, often orogen-parallel strike-slip shear zones. In this study, we analyze drainage systems of several prominent MCCs, and compare their drainage patterns and channel metrics to constrain their geodynamic setting. The Naxos MCC represents an A-type MCC. The Dayman Dome located in Papua New Guinea a B-type MCC, whereas MCCs of the Red River Shear Zone, the Diancang, Ailao-Shan and Day Nui Con Voi complexes, show structural features of the C-type endmember. In the case of the Diancang complex, the MCC is even superimposed by late stage B-type dynamics. The Tauern window and Lepontine dome in the Alps are described as C-type MCCs. We extracted drainage systems and basins and calculated Strahler orders to explore asymmetries in the drainage pattern and to detect evidence for horizontal advection of rivers and catchments. We computed longitudinal river profiles and determined the normalized steepness indexes for channels to uncover regions of spatially variable uplift rates and to constrain the state of landscape adjustment at active MCCs. Furthermore, we analyzed the stability of watersheds by computing so called χ-maps. A-type MCCs show a drainage pattern, which is partly parallel to the stretching and elongation direction, potentially developing from grooves of the detachment. The B-type MCCs show preferences for a radial oriented drainage pattern along lateral terminations. The radial morphology is overprinted by fault systems and neighboring uplifted domes beside the investigation site. A clear preferred direction for further capturing of catchments can be described along detachment zones. The results show an asymmetric alignment of the drainage networks of C-type MCCs, caused by tilting and lateral offset of the streams. One side of the valley shows short streams, whereas the other side is characterized by long, deeply incised streams with a clear tendency to capture adjacent catchments. In C-type MCCs, the drainage pattern develops perpendicular to the trunk streams, which are subparallel to confining faults. The tributaries of the trunk valleys show often dragging in shear direction of the confining fault. The drainage pattern along ductile low-angle normal faults seemingly develops parallel to these faults and shows an asymmetry due to tilting towards the hangingwall block. The analysis reveals that the three types of MCCs can be distinguished by their drainage pattern. All three types have a distinct central drainage divide in common, which is getting elongated in the stretching direction in C-type MCCs and remains small in B-type MCCs. Further early results of our analysis show the high potential of employing morphometric tools in combination with methods from structural geology and low temperature geochronology to determine the type of MCCs, to reveal timing and rates of uplift and horizontal advection, and to constrain the state of landscape adjustment at active MCCs.

Pilot-Scale Selenium Bioremediation of San Joaquin Drainage Water with Thauera selenatis

PubMed Central

Cantafio, A. W.; Hagen, K. D.; Lewis, G. E.; Bledsoe, T. L.; Nunan, K. M.; Macy, J. M.

1996-01-01

This report describes a simple method for the bioremediation of selenium from agricultural drainage water. A medium-packed pilot-scale biological reactor system, inoculated with the selenate-respiring bacterium Thauera selenatis, was constructed at the Panoche Water District, San Joaquin Valley, Calif. The reactor was used to treat drainage water (7.6 liters/min) containing both selenium and nitrate. Acetate (5 mM) was the carbon source-electron donor reactor feed. Selenium oxyanion concentrations (selenate plus selenite) in the drainage water were reduced by 98%, to an average of 12 (plusmn) 9 (mu)g/liter. Frequently (47% of the sampling days), reactor effluent concentrations of less than 5 (mu)g/liter were achieved. Denitrification was also observed in this system; nitrate and nitrite concentrations in the drainage water were reduced to 0.1 and 0.01 mM, respectively (98% reduction). Analysis of the reactor effluent showed that 91 to 96% of the total selenium recovered was elemental selenium; 97.9% of this elemental selenium could be removed with Nalmet 8072, a new, commercially available precipitant-coagulant. Widespread use of this system (in the Grasslands Water District) could reduce the amount of selenium deposited in the San Joaquin River from 7,000 to 140 lb (ca. 3,000 to 60 kg)/year. PMID:16535401

Prophylactic intra-peritoneal drain placement following pancreaticoduodenectomy: A systematic review and meta-analysis

PubMed Central

Wang, Yi-Chao; Szatmary, Peter; Zhu, Jing-Qiang; Xiong, Jun-Jie; Huang, Wei; Gomatos, Ilias; Nunes, Quentin M; Sutton, Robert; Liu, Xu-Bao

2015-01-01

AIM: To conduct a meta-analysis comparing outcomes after pancreaticoduodenectomy (PD) with or without prophylactic drainage. METHODS: Relevant comparative randomized and non-randomized studies were systemically searched based on specific inclusion and exclusion criteria. Postoperative outcomes were compared between patients with and those without routine drainage. Pooled odds ratios (OR) with 95%CI were calculated using either fixed effects or random effects models. RESULTS: One randomized controlled trial and four non-randomized comparative studies recruiting 1728 patients were analyzed. Patients without prophylactic drainage after PD had significantly higher mortality (OR = 2.32, 95%CI: 1.11-4.85; P = 0.02), despite the fact that they were associated with fewer overall complications (OR = 0.62, 95%CI: 0.48-0.82; P = 0.00), major complications (OR = 0.75, 95%CI: 0.60-0.93; P = 0.01) and readmissions (OR = 0.77, 95%CI: 0.60-0.98; P = 0.04). There were no significant differences in the rates of pancreatic fistula, intra-abdominal abscesses, postpancreatectomy hemorrhage, biliary fistula, delayed gastric emptying, reoperation or radiologic-guided drains between the two groups. CONCLUSION: Indiscriminate abandonment of intra-abdominal drainage following PD is associated with greater mortality, but lower complication rates. Future randomized trials should compare routine vs selective drainage. PMID:25741162

A Novel Technique of a Transcorneal Suture to Manage an Iris Tuck into the Tube of a Glaucoma Drainage Device.

PubMed

Kataria, Pankaj; Kaushik, Sushmita; Singh, Simar R; Pandav, Surinder S

2016-08-01

Glaucoma drainage devices create an alternative pathway of aqueous drainage from the anterior chamber by channelling aqueous out of the eye through a tube to a subconjunctival bleb or the suprachoroidal space. They may be associated with a number of potential complications including tube malpositioning. This malpositioning may have serious sequelae such as corneal endothelial damage, chronic iritis, tube iris touch, cataract formation, or tube occlusion. Occlusion of the mouth of the tube by the iris impedes aqueous drainage and results in the failure of intraocular pressure (IOP) control. Tube repositioning in cases of occlusion of the mouth of the tube by the iris often involves extensive and potentially complicated surgery requiring tube removal and reinsertion. We describe a new minimally invasive surgical technique for correcting posterior tube malposition resulting in tube occlusion by the iris. The iris had occluded the tube of a Baerveldt prototype glaucoma drainage devices and caused an intractable increased IOP. After our tube sling suture, the tube was free, and the IOP normalized. The procedure entailed no difficult dissection or major surgical intervention. The technique is illustrated by a surgical video. This novel technique is a simple method that relieved the occlusion successfully, and avoided the need to redissect the conjunctiva or shorten the tube.

Reality named endoscopic ultrasound biliary drainage

PubMed Central

Guedes, Hugo Gonçalo; Lopes, Roberto Iglesias; de Oliveira, Joel Fernandez; Artifon, Everson Luiz de Almeida

2015-01-01

Endoscopic ultrasound (EUS) is used for diagnosis and evaluation of many diseases of the gastrointestinal (GI) tract. In the past, it was used to guide a cholangiography, but nowadays it emerges as a powerful therapeutic tool in biliary drainage. The aims of this review are: outline the rationale for endoscopic ultrasound-guided biliary drainage (EGBD); detail the procedural technique; evaluate the clinical outcomes and limitations of the method; and provide recommendations for the practicing clinician. In cases of failed endoscopic retrograde cholangiopancreatography (ERCP), patients are usually referred for either percutaneous transhepatic biliary drainage (PTBD) or surgical bypass. Both these procedures have high rates of undesirable complications. EGBD is an attractive alternative to PTBD or surgery when ERCP fails. EGBD can be performed at two locations: transhepatic or extrahepatic, and the stent can be inserted in an antegrade or retrograde fashion. The drainage route can be transluminal, duodenal or transpapillary, which, again, can be antegrade or retrograde [rendezvous (EUS-RV)]. Complications of all techniques combined include pneumoperitoneum, bleeding, bile leak/peritonitis and cholangitis. We recommend EGBD when bile duct access is not possible because of failed cannulation, altered upper GI tract anatomy, gastric outlet obstruction, a distorted ampulla or a periampullary diverticulum, as a minimally invasive alternative to surgery or radiology. PMID:26504507

Acidity and alkalinity in mine drainage: Theoretical considerations

USGS Publications Warehouse

Kirby, Carl S.; Cravotta,, Charles A.

2004-01-01

Acidity, net acidity, and net alkalinity are widely used parameters for the characterization of mine drainage, but these terms are not well defined and are often misunderstood. Incorrect interpretation of acidity, alkalinity, and derivative terms can lead to inadequate treatment design or poor regulatory decisions. We briefly explain derivations of theoretical expressions of three types of alkalinities (caustic, phenolphthalein, and total) and acidities (mineral, CO2, and total). Theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined “CO2- acidity” is closely related to most standard titration methods used for mine drainage with an endpoint pH of 8.3, but it presents numerous interpretation problems, and it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/massaction approach and employing graphs for visualization, we explore the concept of principal components and how to assign acidity contributions to solution species, including aqueous complexes, commonly found in mine drainage. We define a comprehensive theoretical definition of acidity in mine drainage on the basis of aqueous speciation at the sample pH and the capacity of these species to undergo hydrolysis to pH 8.3. This definition indicates the computed acidity in milligrams per liter (mg L-1 ) as CaCO3 (based on pH and analytical concentrations of dissolved FeIII , FeII , Mn, and Al in mg L-1 ): Aciditycomputed = 50. (10(3-pH) + 3.CFeIII/55.8 + 2.CFeII/55.8 + 2.CMn/54.9 + 3.CAl/27.0) underestimates contributions from HSO4 - and H+ , but overestimates the acidity due to Fe3+. These errors tend to approximately cancel each other. We demonstrate that “net alkalinity” is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. We demonstrate that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: 1) alkalinity and acidity values based on aqueous speciation, 2) measured alkalinity - computed acidity, or 3) taking the negative of the value obtained in a standard method “hot peroxide” acidity titration, provided that labs report negative values. We recommend the third approach; i.e., Net alkalinity = - Hot Acidity.

Using Campylobacter spp. and Escherichia coli data and Bayesian microbial risk assessment to examine public health risks in agricultural watersheds under tile drainage management.

PubMed

Schmidt, P J; Pintar, K D M; Fazil, A M; Flemming, C A; Lanthier, M; Laprade, N; Sunohara, M D; Simhon, A; Thomas, J L; Topp, E; Wilkes, G; Lapen, D R

2013-06-15

Human campylobacteriosis is the leading bacterial gastrointestinal illness in Canada; environmental transmission has been implicated in addition to transmission via consumption of contaminated food. Information about Campylobacter spp. occurrence at the watershed scale will enhance our understanding of the associated public health risks and the efficacy of source water protection strategies. The overriding purpose of this study is to provide a quantitative framework to assess and compare the relative public health significance of watershed microbial water quality associated with agricultural BMPs. A microbial monitoring program was expanded from fecal indicator analyses and Campylobacter spp. presence/absence tests to the development of a novel, 11-tube most probable number (MPN) method that targeted Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. These three types of data were used to make inferences about theoretical risks in a watershed in which controlled tile drainage is widely practiced, an adjacent watershed with conventional (uncontrolled) tile drainage, and reference sites elsewhere in the same river basin. E. coli concentrations (MPN and plate count) in the controlled tile drainage watershed were statistically higher (2008-11), relative to the uncontrolled tile drainage watershed, but yearly variation was high as well. Escherichia coli loading for years 2008-11 combined were statistically higher in the controlled watershed, relative to the uncontrolled tile drainage watershed, but Campylobacter spp. loads for 2010-11 were generally higher for the uncontrolled tile drainage watershed (but not statistically significant). Using MPN data and a Bayesian modelling approach, higher mean Campylobacter spp. concentrations were found in the controlled tile drainage watershed relative to the uncontrolled tile drainage watershed (2010, 2011). A second-order quantitative microbial risk assessment (QMRA) was used, in a relative way, to identify differences in mean Campylobacter spp. infection risks among monitoring sites for a hypothetical exposure scenario. Greater relative mean risks were obtained for sites in the controlled tile drainage watershed than in the uncontrolled tile drainage watershed in each year of monitoring with pair-wise posterior probabilities exceeding 0.699, and the lowest relative mean risks were found at a downstream drinking water intake reference site. The second-order modelling approach was used to partition sources of uncertainty, which revealed that an adequate representation of the temporal variation in Campylobacter spp. concentrations for risk assessment was achieved with as few as 10 MPN data per site. This study demonstrates for the first time how QMRA can be implemented to evaluate, in a relative sense, the public health implications of controlled tile drainage on watershed-scale water quality. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Frequency of an accessory popliteal efferent lymphatic pathway in dogs.

PubMed

Mayer, Monique N; Sweet, Katherine A; Patsikas, Michael N; Sukut, Sally L; Waldner, Cheryl L

2018-05-01

Staging and therapeutic planning for dogs with malignant disease in the popliteal lymph node are based on the expected patterns of lymphatic drainage from the lymph node. The medial iliac lymph nodes are known to receive efferent lymph from the popliteal lymph node; however, an accessory popliteal efferent pathway with direct connection to the sacral lymph nodes has also been less frequently reported. The primary objective of this prospective, anatomic study was to describe the frequency of various patterns of lymphatic drainage of the popliteal lymph node. With informed client consent, 50 adult dogs with no known disease of the lymphatic system underwent computed tomographic lymphography after ultrasound-guided, percutaneous injection of 350 mg/ml iohexol into a popliteal lymph node. In all 50 dogs, the popliteal lymph node drained directly to the ipsilateral medial iliac lymph node through multiple lymphatic vessels that coursed along the medial thigh. In 26% (13/50) of dogs, efferent vessels also drained from the popliteal lymph node directly to the internal iliac and/or sacral lymph nodes, coursing laterally through the gluteal region and passing over the dorsal aspect of the pelvis. Lymphatic connections between the right and left medial iliac and right and left internal iliac lymph nodes were found. Based on our findings, the internal iliac and sacral lymph nodes should be considered when staging or planning therapy for dogs with malignant disease in the popliteal lymph node. © 2018 American College of Veterinary Radiology.

Novel Split Chest Tube Improves Post-Surgical Thoracic Drainage.

PubMed

Olivencia-Yurvati, Albert H; Cherry, Brandon H; Gurji, Hunaid A; White, Daniel W; Newton, J Tyler; Scott, Gary F; Hoxha, Besim; Gourlay, Terence; Mallet, Robert T

2014-01-01

Conventional, separate mediastinal and pleural tubes are often inefficient at draining thoracic effusions. We developed a Y-shaped chest tube with split ends that divide within the thoracic cavity, permitting separate intrathoracic placement and requiring a single exit port. In this study, thoracic drainage by the split drain vs. that of separate drains was tested. After sternotomy, pericardiotomy, and left pleurotomy, pigs were fitted with separate chest drains (n=10) or a split tube prototype (n=9) with internal openings positioned in the mediastinum and in the costo-diaphragmatic recess. Separate series of experiments were conducted to test drainage of D5W or 0.58 M sucrose, an aqueous solution with viscosity approximating that of plasma. One litre of fluid was infused into the thorax, and suction was applied at -20 cm H2O for 30 min. When D5W was infused, the split drain left a residual volume of 53 ± 99 ml (mean value ± SD) vs. 148 ± 120 for the separate drain (P=0.007), representing a drainage efficiency (i.e. drained vol/[drained + residual vol]) of 95 ± 10% vs. 86 ± 12% for the separate drains (P = 0.011). In the second series, the split drain evacuated more 0.58 M sucrose in the first minute (967 ± 129 ml) than the separate drains (680 ± 192 ml, P<0.001). By 30 min, the split drain evacuated a similar volume of sucrose vs. the conventional drain (1089 ± 72 vs. 1056 ± 78 ml; P = 0.5). Residual volume tended to be lower (25 ± 10 vs. 62 ± 72 ml; P = 0.128) and drainage efficiency tended to be higher (98 ± 1 vs. 95 ± 6%; P = 0.111) with the split drain vs. conventional separate drains. The split chest tube drained the thoracic cavity at least as effectively as conventional separate tubes. This new device could potentially alleviate postoperative complications.

Sedimentary response to orogenic exhumation in the northern rocky mountain basin and range province, flint creek basin, west-central Montana

USGS Publications Warehouse

Portner, R.A.; Hendrix, M.S.; Stalker, J.C.; Miggins, D.P.; Sheriff, S.D.

2011-01-01

Middle Eocene through Upper Miocene sedimentary and volcanic rocks of the Flint Creek basin in western Montana accumulated during a period of significant paleoclimatic change and extension across the northern Rocky Mountain Basin and Range province. Gravity modelling, borehole data, and geologic mapping from the Flint Creek basin indicate that subsidence was focused along an extensionally reactivated Sevier thrust fault, which accommodated up to 800 m of basin fill while relaying stress between the dextral transtensional Lewis and Clark lineament to the north and the Anaconda core complex to the south. Northwesterly paleocurrent indicators, foliated metamorphic lithics, 64 Ma (40Ar/39Ar) muscovite grains, and 76 Ma (U-Pb) zircons in a ca. 27 Ma arkosic sandstone are consistent with Oligocene exhumation and erosion of the Anaconda core complex. The core complex and volcanic and magmatic rocks in its hangingwall created an important drainage divide during the Paleogene shedding detritus to the NNW and ESE. Following a major period of Early Miocene tectonism and erosion, regional drainage networks were reorganized such that paleoflow in the Flint Creek basin flowed east into an internally drained saline lake system. Renewed tectonism during Middle to Late Miocene time reestablished a west-directed drainage that is recorded by fluvial strata within a Late Miocene paleovalley. These tectonic reorganizations and associated drainage divide explain observed discrepancies in provenance studies across the province. Regional correlation of unconformities and lithofacies mapping in the Flint Creek basin suggest that localized tectonism and relative base level fluctuations controlled lithostratigraphic architecture.

Heavy metal transport in large river systems: heavy metal emissions and loads in the Rhine and Elbe river basins

NASA Astrophysics Data System (ADS)

Vink, Rona; Behrendt, Horst

2002-11-01

Pollutant transport and management in the Rhine and Elbe basins is still of international concern, since certain target levels set by the international committees for protection of both rivers have not been reached. The analysis of the chain of emissions of point and diffuse sources to river loads will provide policy makers with a tool for effective management of river basins. The analysis of large river basins such as the Elbe and Rhine requires information on the spatial and temporal characteristics of both emissions and physical information of the entire river basin. In this paper, an analysis has been made of heavy metal emissions from various point and diffuse sources in the Rhine and Elbe drainage areas. Different point and diffuse pathways are considered in the model, such as inputs from industry, wastewater treatment plants, urban areas, erosion, groundwater, atmospheric deposition, tile drainage, and runoff. In most cases the measured heavy metal loads at monitoring stations are lower than the sum of the heavy metal emissions. This behaviour in large river systems can largely be explained by retention processes (e.g. sedimentation) and is dependent on the specific runoff of a catchment. Independent of the method used to estimate emissions, the source apportionment analysis of observed loads was used to determine the share of point and diffuse sources in the heavy metal load at a monitoring station by establishing a discharge dependency. The results from both the emission analysis and the source apportionment analysis of observed loads were compared and gave similar results. Between 51% (for Hg) and 74% (for Pb) of the total transport in the Elbe basin is supplied by inputs from diffuse sources. In the Rhine basin diffuse source inputs dominate the total transport and deliver more than 70% of the total transport. The diffuse hydrological pathways with the highest share are erosion and urban areas.

Study protocol for a randomised controlled trial of invasive versus conservative management of primary spontaneous pneumothorax

PubMed Central

Brown, Simon G A; Ball, Emma L; Perrin, Kyle; Read, Catherine A; Asha, Stephen E; Beasley, Richard; Egerton-Warburton, Diana; Jones, Peter G; Keijzers, Gerben; Kinnear, Frances B; Kwan, Ben C H; Lee, Y C Gary; Smith, Julian A; Summers, Quentin A; Simpson, Graham

2016-01-01

Introduction Current management of primary spontaneous pneumothorax (PSP) is variable, with little evidence from randomised controlled trials to guide treatment. Guidelines emphasise intervention in many patients, which involves chest drain insertion, hospital admission and occasionally surgery. However, there is evidence that conservative management may be effective and safe, and it may also reduce the risk of recurrence. Significant questions remain regarding the optimal initial approach to the management of PSP. Methods and analysis This multicentre, prospective, randomised, open label, parallel group, non-inferiority study will randomise 342 participants with a first large PSP to conservative or interventional management. To maintain allocation concealment, randomisation will be performed in real time by computer and stratified by study site. Conservative management will involve a period of observation prior to discharge, with intervention for worsening symptoms or physiological instability. Interventional treatment will involve insertion of a small bore drain. If drainage continues after 1 hour, the patient will be admitted. If drainage stops, the drain will be clamped for 4 hours. The patient will be discharged if the lung remains inflated. Otherwise, the patient will be admitted. The primary end point is the proportion of participants with complete lung re-expansion by 8 weeks. Secondary end points are as follows: days in hospital, persistent air leak, predefined complications and adverse events, time to resolution of symptoms, and pneumothorax recurrence during a follow-up period of at least 1 year. The study has 95% power to detect an absolute non-inferiority margin of 9%, assuming 99% successful expansion at 8 weeks in the invasive treatment arm. The primary analysis will be by intention to treat. Ethics and dissemination Local ethics approval has been obtained for all sites. Study findings will be disseminated by publication in a high-impact international journal and presentation at major international Emergency Medicine and Respiratory meetings. Trial registration number ACTRN12611000184976; Pre-results. PMID:27625060

Burr-hole drainage for the treatment of acute epidural hematoma in coagulopathic patients: a report of eight cases.

PubMed

Habibi, Zohreh; Meybodi, Ali Tayebi; Haji Mirsadeghi, Seyed Mohammad; Miri, Seyed Mojtaba

2012-07-20

Craniotomy has been accepted as the treatment of choice for the management of acute epidural hematomas (AEDH). However, in practice, it seems possible to evacuate AEDH via a single burr hole instead of the traditional craniotomy in certain circumstances. Among 160 patients with AEDH meeting criteria for evacuation admitted to the emergency and accident division of our center between 2006 and 2009, we found 8 cases of hematoma appearing isodense to brain parenchyma on computed tomography (CT), who had concomitant coagulopathy. These patients were managed by burr-hole drainage for treatment of the liquefied AEDH. A closed drainage system was then kept in the epidural space for 3 days. In all 8 patients, AEDH was evacuated successfully via burr-hole placement over the site of hematoma. The level of consciousness and other symptoms improved within the first day, and no patient required an additional routine craniotomy. For patients with slowly-developing AEDH in the context of impaired coagulation, burr-hole evacuation and drainage might be a less invasive method of treatment compared to conventional craniotomy.

The management of vacuum neck drains in head and neck surgery and the comparison of two different practice protocols for drain removal.

PubMed

Kasbekar, A V; Davies, F; Upile, N; Ho, M W; Roland, N J

2016-01-01

Introduction The management of vacuum neck drains in head and neck surgery is varied. We aimed to improve early drain removal and therefore patient discharge in a safe and effective manner. Methods The postoperative management of head and neck surgical patients with vacuum neck drains was reviewed retrospectively. A new policy was then implemented to measure drainage three times daily (midnight, 6am, midday). The decision for drain removal was based on the most recent drainage period (at <3ml per hour). A further patient cohort was subsequently assessed prospectively. The length of hospital stay was compared between the cohorts. Results The retrospective audit included 51 patients while the prospective audit included 47. The latter saw 16 patients (33%) discharged at least one day earlier than they would have been under the previous policy. No adverse effects were noted from earlier drain removal. Conclusions Measuring drainage volumes three times daily allows for more accurate assessment of wound drainage, and this can lead to earlier removal of neck drains and safe discharge.

Preliminary appraisal of the geohydrologic aspects of drainage wells, Orlando area, central Florida

USGS Publications Warehouse

Kimrey, Joel O.

1978-01-01

The Floridan aquifer contains two highly transmissive cavernous zones in the Orlando area: an upper producing zone about 150-600 feet below land surface; and a lower producing zone about 1,100-1,500 feet below land surface. Natural head differences are downward and there is hydraulic connection between the two producing zones. Drainage wells are finished open-end into the upper producing zone and emplace surface waters directly into that zone by gravity. Quantitatively, their use constitutes an effective method of artificial recharge. Their negative aspects relate to the probably poor, but unknown, quality of the recharge water. Caution is suggested in drawing definite and final conclusions on the overall geohydrologic and environmental effects of drainage wells prior to the collection and interpretation of a considerable quantity of new data. Though few ground-water pollution problems have been documented to date, the potential for such pollution should be seriously considered in light of the prob-able continuing need to use drainage wells; the probable volumes and quality of water involved; and the hydraulic relations between the two producing zones.

Net alkalinity and net acidity 1: Theoretical considerations

USGS Publications Warehouse

Kirby, C.S.; Cravotta, C.A.

2005-01-01

Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a standard method "hot peroxide" acidity titration, provided that labs report negative values. The authors recommend the third approach; i.e., net alkalinity = -Hot Acidity. ?? 2005 Elsevier Ltd. All rights reserved.

STATISTICAL VALIDATION OF SULFATE QUANTIFICATION METHODS USED FOR ANALYSIS OF ACID MINE DRAINAGE

EPA Science Inventory

Turbidimetric method (TM), ion chromatography (IC) and inductively coupled plasma atomic emission spectrometry (ICP-AES) with and without acid digestion have been compared and validated for the determination of sulfate in mining wastewater. Analytical methods were chosen to compa...

[Tentorial Dural Arteriovenous Fistula Successfully Treated with Transvenous Embolization Using a Double Catheterization Technique through Venous Drainage:A Case Report].

PubMed

Yamakawa, Akira; Fujita, Atsushi; Tanaka, Hirotomo; Ikeda, Mitsuru; Morikawa, Masashi; Kohmura, Eiji

2017-07-01

Tentorial dural arteriovenous fistulas(dAVFs)are a rare clinical entity accounting for less than 10% of all intracranial dAVFs. Because these lesions are characterized by high hemorrhagic risk, aggressive treatment should be considered. Although the number of reported cases treated with endovascular transarterial embolization(TAE)using glue has been increasing, little is known about the transvenous approach. Here, we report the case of a patient with a tentorial dAVF who was successfully treated with transvenous embolization(TVE)through venous drainage using a double catheterization technique. A 68-year-old male patient who had a history of left putaminal hemorrhage treated with a craniotomy was diagnosed with a tentorial dAVF on a magnetic resonance angiogram. Because the patient refused another craniotomy for surgical interruption of the dAVF, an endovascular approach was considered. We first attempted to perform TAE with glue, but catheterization into the tortuous meningohypophyseal trunk failed. We then performed a TVE of the venous drainage near the shunt with detachable coils and achieved complete obliteration of the fistula. During coil embolization of the venous drainage, insertion of small coils near the shunt was supported by another anchor coil that was delivered using a double catheterization technique. The method of TVE through venous drainage using a double catheterization technique, which involved placing coils in the fragile drainage vein, was safe and effective in a case of tentorial dAVF. This technique should be considered as another option for the management of complex tentorial dAVFs.

Numerical study on non-locally reacting behavior of nacelle liners incorporating drainage slots

NASA Astrophysics Data System (ADS)

Chen, Chao; Li, Xiaodong; Thiele, Frank

2018-06-01

For acoustic liners used in current commercial nacelles, in order to prevent any liquid accumulating in the resonators, drainage slots are incorporated on the partition walls between closely packed cavities. Recently, an experimental study conducted by Busse-Gerstengarbe et al. shown that the cell interaction introduced by drainage slots causes an additional dissipation peak which increases with the size of the slot. However, the variation of damping process due to drainage slots is still not fully understood. Therefore, a numerical study based on computational aeroacoustic methods is carried out to investigate the mechanism of the changed attenuation characteristics due to drainage slots in presence of grazing incident sound waves with low or high intensities. Different slot configurations are designed based on the generic non-locally reacting liner model adopted in the experimental investigation. Both 2-D and 3-D numerical simulations of only slit resonators are carried out. Numerical results indicate that the extra peak is a result of a resonance excited in the second cavity at specific frequency. Under high sound pressure level incoming waves, the basic characteristics of the acoustic performance remain. However, vortex shedding transpires at the resonances around both the slits and the drainage slot. Vorticity contours show that the connection of two coupled cavities decreases the strength of vortex shedding around the basic Helmholtz resonance due to a higher energy reflection. Meanwhile, the cell interaction significantly increases the vorticity magnitude near the extra resonant frequency. Finally, a semi-empirical model is derived to predict the extra attenuation peak frequency.

Correction of differential renal function for asymmetric renal area ratio in unilateral hydronephrosis.

PubMed

Aktaş, Gul Ege; Sarıkaya, Ali

2015-11-01

Children with unilateral hydronephrosis are followed up with anteroposterior pelvic diameter (APD), hydronephrosis grade, mercaptoacetyltriglycine (MAG-3) drainage pattern and differential renal function (DRF). Indeterminate drainage preserved DRF in higher grades of hydronephrosis, in some situations, complicating the decision-making process. Due to an asymmetric renal area ratio, falsely negative DRF estimations can result in missed optimal surgery times. This study was designed to assess whether correcting the DRF estimation according to kidney area could reflect the clinical situation of a hydronephrotic kidney better than a classical DRF calculation, concurrently with the hydronephrosis grade, APD and MAG-3 drainage pattern. We reviewed the MAG-3, dimercaptosuccinic acid (DMSA) scans and ultrasonography (US) of 23 children (6 girls, 17 boys, mean age: 29 ± 50 months) with unilateral hydronephrosis. MAG-3 and DMSA scans were performed within 3 months (mean 25.4 ± 30.7 days). The closest US findings (mean 41.5 ± 28.2 days) were used. DMSA DRF estimations were obtained using the geometric mean method. Secondary calculations were performed to correct the counts (the total counts divided by the number of pixels in ROI) according to kidney area. The renogram patterns of patients were evaluated and separated into subgroups. The visual assessment of DMSA scans was noted and the hydronephrotic kidney was classified in comparison to the normal contralateral kidney's uptake. The correlations of the DRF values of classical and area-corrected methods with MAG-3 renogram patterns, the visual classification of DMSA scan, the hydronephrosis grade and the APD were assessed. DRF estimations of two methods were statistically different (p: 0.001). The categories of 12 hydronephrotic kidneys were changed. There were no correlations between classical DRF estimations and the hydronephrosis grade, APD, visual classification of the DMSA scan and uptake evaluation. The DRF distributions according to MAG-3 drainage patterns were not different. Area-corrected DRF estimations correlated with all: with an increasing hydronephrosis grade and APD, DRF estimations decreased and MAG-3 drainage patterns worsened. A decrease in DRF (< 45 %) was determined when APD was ≥ 10 mm. When APD was ≥ 26 mm, a reduction of DRF below 40 % was determined. Our results suggest that correcting DRF estimation for asymmetric renal area ratio in unilateral hydronephrosis can be more robust than the classical method, especially for higher grades of hydronephrotic kidneys, under equivocal circumstances.

Enabling high-quality observations of surface imperviousness for water runoff modelling from unmanned aerial vehicles

NASA Astrophysics Data System (ADS)

Tokarczyk, Piotr; Leitao, Joao Paulo; Rieckermann, Jörg; Schindler, Konrad; Blumensaat, Frank

2015-04-01

Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the area. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increase as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data is unavailable. Modern unmanned air vehicles (UAVs) allow acquiring high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements, and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility to derive high-resolution imperviousness maps for urban areas from UAV imagery and to use this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is tested and applied in a state-of-the-art urban drainage modelling exercise. In a real-life case study in the area of Lucerne, Switzerland, we compare imperviousness maps generated from a consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their correctness, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyze the surface runoff of the 307 individual sub-catchments regarding relevant attributes, such as peak runoff and volume. Finally, we evaluate the model's channel flow prediction performance through a cross-comparison with reference flow measured at the catchment outlet. We show that imperviousness maps generated using UAV imagery processed with modern classification methods achieve accuracy comparable with standard, off-the-shelf aerial imagery. In the examined case study, we find that the different imperviousness maps only have a limited influence on modelled surface runoff and pipe flows. We conclude that UAV imagery represents a valuable alternative data source for urban drainage model applications due to the possibility to flexibly acquire up-to-date aerial images at a superior quality and a competitive price. Our analyses furthermore suggest that spatially more detailed urban drainage models can even better benefit from the full detail of UAV imagery.

High-quality observation of surface imperviousness for urban runoff modelling using UAV imagery

NASA Astrophysics Data System (ADS)

Tokarczyk, P.; Leitao, J. P.; Rieckermann, J.; Schindler, K.; Blumensaat, F.

2015-01-01

Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the area. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increase as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data is unavailable. Modern unmanned air vehicles (UAVs) allow acquiring high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements, and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility to derive high-resolution imperviousness maps for urban areas from UAV imagery and to use this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is tested and applied in a state-of-the-art urban drainage modelling exercise. In a real-life case study in the area of Lucerne, Switzerland, we compare imperviousness maps generated from a consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their correctness, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyze the surface runoff of the 307 individual subcatchments regarding relevant attributes, such as peak runoff and volume. Finally, we evaluate the model's channel flow prediction performance through a cross-comparison with reference flow measured at the catchment outlet. We show that imperviousness maps generated using UAV imagery processed with modern classification methods achieve accuracy comparable with standard, off-the-shelf aerial imagery. In the examined case study, we find that the different imperviousness maps only have a limited influence on modelled surface runoff and pipe flows. We conclude that UAV imagery represents a valuable alternative data source for urban drainage model applications due to the possibility to flexibly acquire up-to-date aerial images at a superior quality and a competitive price. Our analyses furthermore suggest that spatially more detailed urban drainage models can even better benefit from the full detail of UAV imagery.

Methods for estimating selected flow-duration and flood-frequency characteristics at ungaged sites in Central Idaho

USGS Publications Warehouse

Kjelstrom, L.C.

1998-01-01

Methods for estimating daily mean discharges for selected flow durations and flood discharge for selected recurrence intervals at ungaged sites in central Idaho were applied using data collected at streamflow-gaging stations in the area. The areal and seasonal variability of discharge from ungaged drainage basins may be described by estimating daily mean discharges that are exceeded 20, 50, and 80 percent of the time each month. At 73 gaging stations, mean monthly discharge was regressed with discharge at three points—20, 50, and 80—from daily mean flow-duration curves for each month. Regression results were improved by dividing the study area into six regions. Previously determined estimates of mean monthly discharge from about 1,200 ungaged drainage basins provided the basis for applying the developed techniques to the ungaged basins. Estimates of daily mean discharges that are exceeded 20, 50, and 80 percent of the time each month at ungaged drainage basins can be made by multiplying mean monthly discharges estimated at ungaged sites by a regression factor for the appropriate region. In general, the flow-duration data were less accurately estimated at discharges exceeded 80 percent of the time than at discharges exceeded 20 percent of the time. Curves drawn through the three points for each of the six regions were most similar in July and most different from December through March. Coefficients of determination of the regressions indicate that differences in mean monthly discharge largely explain differences in discharge at points on the daily mean flow-duration curve. Inherent in the method are errors in the technique used to estimate mean monthly discharge. Flood discharge estimates for selected recurrence intervals at ungaged sites upstream or downstream from gaging stations can be determined by a transfer technique. A weighted ratio of drainage area times flood discharge for selected recurrence intervals at the gaging station can be used to estimate flood discharge at the ungaged site. Best results likely are obtained when the difference between gaged and ungaged drainage areas is small.

Advances in endoscopic retrograde cholangiopancreatography for the treatment of cholangiocarcinoma

PubMed Central

Uppal, Dushant S; Wang, Andrew Y

2015-01-01

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts that carries high morbidity and mortality. Patients with CCA typically present with obstructive jaundice, and associated complications of CCA include cholangitis and biliary sepsis. Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable treatment modality for patients with CCA, as it enables internal drainage of blocked bile ducts and hepatic segments by using plastic or metal stents. While there remains debate as to if bilateral (or multi-segmental) hepatic drainage is required and/or superior to unilateral drainage, the underlying tenant of draining any persistently opacified bile ducts is paramount to good ERCP practice and good clinical outcomes. Endoscopic therapy for malignant biliary strictures from CCA has advanced to include ablative therapies via ERCP-directed photodynamic therapy (PDT) or radiofrequency ablation (RFA). While ERCP techniques cannot cure CCA, advancements in the field of ERCP have enabled us to improve upon the quality of life of patients with inoperable and incurable disease. ERCP-directed PDT has been used in lieu of brachytherapy to provide neoadjuvant local tumor control in patients with CCA who are awaiting liver transplantation. Lastly, mounting evidence suggests that palliative ERCP-directed PDT, and probably ERCP-directed RFA as well, offer a survival advantage to patients with this difficult-to-treat malignancy. PMID:26140095

Advances in endoscopic retrograde cholangiopancreatography for the treatment of cholangiocarcinoma.

PubMed

Uppal, Dushant S; Wang, Andrew Y

2015-06-25

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts that carries high morbidity and mortality. Patients with CCA typically present with obstructive jaundice, and associated complications of CCA include cholangitis and biliary sepsis. Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable treatment modality for patients with CCA, as it enables internal drainage of blocked bile ducts and hepatic segments by using plastic or metal stents. While there remains debate as to if bilateral (or multi-segmental) hepatic drainage is required and/or superior to unilateral drainage, the underlying tenant of draining any persistently opacified bile ducts is paramount to good ERCP practice and good clinical outcomes. Endoscopic therapy for malignant biliary strictures from CCA has advanced to include ablative therapies via ERCP-directed photodynamic therapy (PDT) or radiofrequency ablation (RFA). While ERCP techniques cannot cure CCA, advancements in the field of ERCP have enabled us to improve upon the quality of life of patients with inoperable and incurable disease. ERCP-directed PDT has been used in lieu of brachytherapy to provide neoadjuvant local tumor control in patients with CCA who are awaiting liver transplantation. Lastly, mounting evidence suggests that palliative ERCP-directed PDT, and probably ERCP-directed RFA as well, offer a survival advantage to patients with this difficult-to-treat malignancy.

THE INFLUENCE OF PHYSICAL FACTORS ON COMPARATIVE PERFORMANCE OF SAMPLING METHODS IN LARGE RIVERS

EPA Science Inventory

In 1999, we compared five existing benthic macroinvertebrate sampling methods used in boatable rivers. Each sampling protocol was performed at each of 60 sites distributed among four rivers in the Ohio River drainage basin. Initial comparison of methods using key macroinvertebr...

[Selection of type of urinary tract drainage in laparoscopic ureterolithotomy].

PubMed

Kisliakov, D A; Sirota, E S; Shpot', E V; Enikeev, M É

2014-01-01

The article presents the results of 44 laparoscopic ureterolithotomies performed for large stones in upper and middle third of the ureter. Patients' age ranged from 35 to 82 years. The different types of drainage of the urinary tract depending on the characteristics of surgical treatment (retro- or transperitoneal ureterolithotomy) were used. The effectiveness was evaluated according to the results of plain urography, ultrasound, and multi-layer spiral CT. The results showed that the preferred method of urinary tract drainage is a preoperative deployment of ureteral catheter-stent. However, in the case of impossibility of such procedure, preoperative deployment of ureteral catheter with subsequent intraoperative replacing it on catheter-stent is permissible. With retroperitoneal approach, tubeless ureterolithotomy is feasible in the absence of the ipsilateral kidney stones, residual ureteral stones and pronounced changes in the area of finding the stones.

Water-quality data from two agricultural drainage basins in northwestern Indiana and northeastern Illinois: I. Lagrangian and synoptic data, 1999-2002

USGS Publications Warehouse

Antweiler, Ronald C.; Smith, Richard L.; Voytek, Mary A.; Bohlke, John Karl; Richards, Kevin D.

2005-01-01

Methods of data collection and results of analyses are presented for Lagrangian and synoptic water-quality data collected from two agricultural drainages, the Iroquois River in northwestern Indiana and Sugar Creek in northwestern Indiana and northeastern Illinois. During six separate sampling trips, in April, June and September 1999, May 2000, September 2001 and April 2002, 152 discrete water samples were collected to characterize the water chemistry over the course of 2 to 4 days on each of these drainages. Data were collected for nutrients, major inorganic constituents, dissolved organic carbon, trace elements, dissolved gases, total bacterial cell counts, chlorophyll-a concentrations, and suspended sediment concentrations. In addition, field measurements of streamflow, pH, specific conductance, water temperature, and dissolved oxygen concentration were made during all trips except April 1999.

Coupled flow and deformations in granular systems beyond the pendular regime

NASA Astrophysics Data System (ADS)

Yuan, Chao; Chareyre, Bruno; Darve, Felix

2017-06-01

A pore-scale numerical model is proposed for simulating the quasi-static primary drainage and the hydro-mechanical couplings in multiphase granular systems. The solid skeleton is idealized to a dense random packing of polydisperse spheres by DEM. The fluids (nonwetting and wetting phases) space is decomposed to a network of tetrahedral pores based on the Regular Triangulation method. The local drainage rules and invasion logic are defined. The fluid forces acting on solid grains are formulated. The model can simulate the hydraulic evolution from a fully saturated state to a low level of saturation but beyond the pendular regime. The features of wetting phase entrapments and capillary fingering can also be reproduced. Finally, a primary drainage test is performed on a 40,000 spheres of sample. The water retention curve is obtained. The solid skeleton first shrinks then swells.

Best option for preoperative biliary drainage in Klatskin tumor

PubMed Central

Tang, Zengwei; Yang, Yuan; Meng, Wenbo; Li, Xun

2017-01-01

Abstract The operative treatment combined with preoperative biliary drainage (PBD) has been established as a safe Klatskin tumor (KT) treatment strategy. However, there has always been a dispute for the preferred technique for PBD technique. This meta-analysis was conducted to compare the biliary drainage-related cholangitis, pancreatitis, hemorrhage, and the success rates of palliative relief of cholestasis between percutaneous transhepatic biliary drainage (PTBD) and endoscopic biliary drainage (EBD), to identify the best technique in the management of KT. PubMed, EMBASE, and Web of Science were searched systematically for prospective or retrospective studies reporting the biliary drainage-related cholangitis, pancreatitis, hemorrhage, and the success rates of palliative relief of cholestasis in patients with KT. A meta-analysis was performed, using the fixed or random-effect model, with Review Manager 5.3. PTBD was associated with lower risk of cholangitis (risk ratio [RR] = 0.49, 95% confidence interval [CI]: 0.36–0.67; P < .00001), particularly in patients with Bismuth-Corlette type II, III, IV KT (RR = 0.50, 95% CI: 0.33–0.77; P = .05). Compared with EBD, PTBD was also associated with a lower risk of pancreatitis (RR = 0.35, 95% CI: 0.17–0.69; P = 0.003) and with higher successful rates of palliative relief of cholestasis (RR = 1.20, 95% CI: 1.10–1.31; P < .0001). The incidence of hemorrhage was similar in these 2 groups (RR 1.29, 95% CI: 0.51–3.27; P = .59). The risk of biliary drainage-related cholangitis (RR = 1.96, 95% CI: 0.96–4.01; P = .06) and pancreatitis (RR = 1.62, 95% CI: 0.76–3.47; P = .21) was similar between endoscopic nasobiliary drainage groups and biliary stenting. In patients with type II or type III or IV KT who need to have PBD, PTBD should be performed as an initial method of biliary drainage in terms of reducing the incidence of procedure related cholangitis, pancreatitis, and improving the rates of palliative relief of cholestasis. Well-conducted randomized controlled trials with a universial criterion for PBD are required to confirm these findings. PMID:29069029

Assessment of Nitrate-N Load in Subsurface Drainage Water from the Agricultural Fields in the Fergana Valley, Uzbekistan

NASA Astrophysics Data System (ADS)

Kenjabaev, S.; Forkutsa, I.; Dukhovny, V.; Frede, H. G.

2012-04-01

Leaching of nitrate-N (NO3-) from irrigated agricultural land and water contamination have become a worldwide concern. This study was conducted to investigate amount of nitrate-N leached to groundwater and surface water from irrigated cotton, winter wheat and maize fields in the Fergana Valley (Uzbekistan). Therefore at two sites ("Akbarabad" and "Azizbek") equipped with closed horizontal drainage system during 2010-2011 vegetation seasons we monitored water flow, nutrient concentrations and salinity at surface and subsurface drains, at irrigation canals and groundwater. We also applied stable isotopes (δ2H and δ18O) method in order to investigate the source of drainage water runoff. Discussed are results of 2010. Farmers fertilized cotton fields with ammonium nitrate of 350-450 kg ha-1 in "Akbarabad" and 700 kg ha-1 in "Azizbek" sites. In winter wheat and maize fields (in "Akbarabad") about 500 kg ha-1 of ammonium nitrate were applied. Cotton fields were irrigated with 2700 m3 ha-1 ("Akbarabad") and 3500 m3 ha-1 ("Azizbek"). In winter wheat and maize fields applied irrigation water amounted to 3900 m3 ha-1 and 723 m3 ha-1, respectively. Frequent groundwater and subsurface drainage water sampling revealed that nitrate leaching occurred mostly during and right after the irrigation events. The estimated average nitrate-N concentration in subsurface drainage water in "Akbarabad" was slightly higher (9 mg l-1) than in "Azizbek" (8 mg l-1). During July-November (2010), in average, nitrate-N losses through subsurface drainage amounted to 24 kg ha-1 in "Akbarabad" and 18 kg ha-1 in "Azizbek". The salinity of drainage water at both sites was similar and varied between 2.3-2.7 dS m-1. Preliminary results of isotope signals of studied water (precipitation, drainage, irrigation and ground water) indicate that the source of drainage water runoff comes from the irrigation water, while the contribution of rainfall is negligible. It is planned to run simulations with DRAINMOD model for further investigation of water and N balances of the selected sites. Developed recommendations for farmers on optimum irrigation water amounts and N fertilization will allow reducing environmental risks in agricultural lands of the Fergana Valley.

Sterile Fluid Collections in Acute Pancreatitis: Catheter Drainage Versus Simple Aspiration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walser, Eric M.; Nealon, William H.; Marroquin, Santiago

2006-02-15

Purpose. To compare the clinical outcome of needle aspiration versus percutaneous catheter drainage of sterile fluid collections in patients with acute pancreatitis. Methods. We reviewed the clinical and imaging data of patients with acute pancreatic fluid collections from 1998 to 2003. Referral for fluid sampling was based on elevated white blood cell count and fevers. Those patients with culture-negative drainages or needle aspirations were included in the study. Fifteen patients had aspiration of 10-20 ml fluid only (group A) and 22 patients had catheter placement for chronic evacuation of fluid (group C). We excluded patients with grossly purulent collections andmore » chronic pseudocysts. We also recorded the number of sinograms and catheter changes and duration of catheter drainage. The CT severity index, Ranson scores, and maximum diameter of abdominal fluid collections were calculated for all patients at presentation. The total length of hospital stay (LOS), length of hospital stay after the drainage or aspiration procedure (LOS-P), and conversions to percutaneous and/or surgical drainage were recorded as well as survival. Results. The CT severity index and acute Ransom scores were not different between the two groups (p = 0.15 and p = 0.6, respectively). When 3 crossover patients from group A to group C were accounted for, the duration of hospitalization did not differ significantly, with a mean LOS and LOS-P of 33.8 days and 27.9 days in group A and 41.5 days and 27.6 days in group C, respectively (p = 0.57 and 0.98, respectively). The 60-day mortality was 2 of 15 (13%) in group A and 2 of 22 (9.1%) in group C. Kaplan-Meier survival curves for the two groups were not significantly different (p 0.3). Surgical or percutaneous conversions occurred significantly more often in group A (7/15, 47%) than surgical conversions in group C (4/22, 18%) (p 0.03). Patients undergoing catheter drainage required an average of 2.2 sinograms/tube changes and kept catheters in for an average of 52 days. Aspirates turned culture-positive in 13 of 22 patients (59%) who had chronic catheterization. In group A, 3 of the 7 patients converted to percutaneous or surgical drainage had infected fluid at the time of conversion (total positive culture rate in group A 3/15 or 20%). Conclusions. There is no apparent clinical benefit for catheter drainage of sterile fluid collections arising in acute pancreatitis as the length of hospital stay and mortality were similar between patients undergoing aspiration versus catheter drainage. However, almost half of patients treated with simple aspiration will require surgical or percutaneous drainage at some point. Disadvantages of chronic catheter drainage include a greater than 50% rate of bacterial colonization and the need for multiple sinograms and tube changes over an average duration of about 2 months.« less

Development of flood probability charts for urban drainage network in coastal areas through a simplified joint assessment approach

NASA Astrophysics Data System (ADS)

Archetti, R.; Bolognesi, A.; Casadio, A.; Maglionico, M.

2011-04-01

The operating conditions of urban drainage networks during storm events certainly depend on the hydraulic conveying capacity of conduits but also on downstream boundary conditions. This is particularly true in costal areas where the level of the receiving water body is directly or indirectly affected by tidal or wave effects. In such cases, not just different rainfall conditions (varying intensity and duration), but also different sea-levels and their effects on the network operation should be considered. This paper aims to study the behaviour of a seaside town storm sewer network, estimating the threshold condition for flooding and proposing a simplified method to assess the urban flooding severity as a function of either climate variables. The case study is a portion of the drainage system of Rimini (Italy), implemented and numerically modelled by means of InfoWorks CS code. The hydraulic simulation of the sewerage system has therefore allowed to identify the percentage of nodes of the drainage system where flooding is expected to occur. Combining these percentages with both climate variables values has lead to the definition charts representing the combined degree of risk "sea-rainfall" for the drainage system under investigation. A final comparison between such charts and the results obtained from a one-year sea-rainfall time series has confirmed the reliability of the analysis.

Development of flood probability charts for urban drainage network in coastal areas through a simplified joint assessment approach

NASA Astrophysics Data System (ADS)

Archetti, R.; Bolognesi, A.; Casadio, A.; Maglionico, M.

2011-10-01

The operating conditions of urban drainage networks during storm events depend on the hydraulic conveying capacity of conduits and also on downstream boundary conditions. This is particularly true in coastal areas where the level of the receiving water body is directly or indirectly affected by tidal or wave effects. In such cases, not just different rainfall conditions (varying intensity and duration), but also different sea-levels and their effects on the network operation should be considered. This paper aims to study the behaviour of a seaside town storm sewer network, estimating the threshold condition for flooding and proposing a simplified method to assess the urban flooding severity as a function of climate variables. The case study is a portion of the drainage system of Rimini (Italy), implemented and numerically modelled by means of InfoWorks CS code. The hydraulic simulation of the sewerage system identified the percentage of nodes of the drainage system where flooding is expected to occur. Combining these percentages with both climate variables' values has lead to the definition of charts representing the combined degree of risk "rainfall-sea level" for the drainage system under investigation. A final comparison between such charts and the results obtained from a one-year rainfall-sea level time series has demonstrated the reliability of the analysis.

CT-Guided Percutaneous Drainage of Infected Collections Due to Gastric Leak After Sleeve Gastrectomy for Morbid Obesity: Initial Experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelogrigoris, M., E-mail: kelogre.mic@hotmail.com; Sotiropoulou, E.; Stathopoulos, K.

This study was designed to evaluate the efficacy and safety of computed tomography (CT)-guided drainage in treating infected collections due to gastric leak after laparoscopic sleeve gastrectomy for morbid obesity. From January 2007 to June 2009, 21 patients (9 men and 12 women; mean age, 39.2 (range, 26-52) years) with infected collections due to gastric leak after laparoscopic sleeve gastrectomy for morbid obesity underwent image-guided percutaneous drainage. All procedures were performed using CT guidance and 8- to 12-Fr pigtail drainage catheters. Immediate technical success was achieved in all 21 infected collections. In 18 of 21 collections, we obtained progressive shrinkagemore » of the collection with consequent clinical success (success rate 86%). In three cases, the abdominal fluid collection was not resolved, and the patients were reoperated. Among the 18 patients who avoided surgery, 2 needed replacement of the catheter due to obstruction. No major complications occurred during the procedure. The results of our study support that CT-guided percutaneous drainage is an effective and safe method to treat infected abdominal fluid collections due to gastric leak in patients who had previously underwent laparoscopic sleeve gastrectomy for morbid obesity. It may be considered both as a preparatory step for surgery and a valuable alternative to open surgery. Failure of the procedure does not, however, preclude a subsequent surgical operation.« less

Meta-Analysis of Drainage Versus No Drainage After Laparoscopic Cholecystectomy

PubMed Central

Lucarelli, Pierino; Di Filippo, Annalisa; De Angelis, Francesco; Stipa, Francesco; Spaziani, Erasmo

2014-01-01

Background and Objectives: Routine drainage after laparoscopic cholecystectomy is still controversial. This meta-analysis was performed to assess the role of drains in reducing complications in laparoscopic cholecystectomy. Methods: An electronic search of Medline, Science Citation Index Expanded, Scopus, and the Cochrane Library database from January 1990 to June 2013 was performed to identify randomized clinical trials that compare prophylactic drainage with no drainage in laparoscopic cholecystectomy. The odds ratio for qualitative variables and standardized mean difference for continuous variables were calculated. Results: Twelve randomized controlled trials were included in the meta-analysis, involving 1939 patients randomized to a drain (960) versus no drain (979). The morbidity rate was lower in the no drain group (odds ratio, 1.97; 95% confidence interval, 1.26 to 3.10; P = .003). The wound infection rate was lower in the no drain group (odds ratio, 2.35; 95% confidence interval, 1.22 to 4.51; P = .01). Abdominal pain 24 hours after surgery was less severe in the no drain group (standardized mean difference, 2.30; 95% confidence interval, 1.27 to 3.34; P < .0001). No significant difference was present with respect to the presence and quantity of subhepatic fluid collection, shoulder tip pain, parenteral ketorolac consumption, nausea, vomiting, and hospital stay. Conclusion: This study was unable to prove that drains were useful in reducing complications in laparoscopic cholecystectomy. PMID:25516708

[An application of low-invasive access in ultrasound-guided surgery of liquid formation of the abdominal cavity and retroperitoneal space].

PubMed

Demin, D B; Laĭkov, A V; Funygin, M S; Chegodaeva, A A; Solodov, Iu Iu; Butina, K V

2014-01-01

The article presents a low-invasive method in the intraoperative ultrasound-guided surgery. The method had several steps: an access (2-3 cm) was made to a liquid formation with the following aspiration of contents, a necrotic detritus was removed through the wound tract using simultaneous ultrasound examination of efficacy of emptying the cavity with drainage. This means allowed the performance of single-stage sanitization and drainage of cavity formations, which contained the liquid and dense necrotic tissues in the lumen. The method was effective, technically workable in any surgical hospital. At the same time, it was economically reasonable, because there wasn't need to buy an additional equipment. The application of the means considerably shortened a hospital stay and the lethality was reduced.

Contractile markers distinguish structures of the mouse aqueous drainage tract

PubMed Central

Ko, MinHee K.

2013-01-01

Purpose Structures of the aqueous humor drainage tract are contractile, although the tract is not entirely composed of muscle. We characterized the mouse aqueous drainage tract by immunolabeling contractile markers and determined whether profiling these markers within the tract distinguished its key structures of the trabecular meshwork (TM) and ciliary muscle (CM). Methods Enucleated eyes from pigmented C57BL/6 (n=8 mice) and albino BALB/c (n=6 mice) mice were processed for cryo- and formalin-fixed paraffin-embedded sectioning. Immunofluorescence labeling was performed for the following: (a) filamentous actin (using fluorescence-conjugated phalloidin), representing a global contractile marker; (b) α-smooth muscle actin (α-SMA), caldesmon, and calponin, representing classic smooth muscle epitopes; and (c) nonmuscle myosin heavy chain, representing a nonmuscle contractile protein. Tissue labeling was identified by confocal microscopy and analyzed quantitatively. Hematoxylin and eosin staining provided structural orientation. Results A small portion of the TM faced the anterior chamber; the rest extended posteriorly alongside Schlemm’s canal (SC) within the inner sclera. Within the drainage tract, filamentous actin labeling was positive in TM and CM. α-SMA and caldesmon labeling was seen primarily along the CM, which extended from the anterior chamber angle to its posterior termination beyond the SC near the retina. Low intensity, patchy α-SMA and caldesmon labeling was seen in the TM. Myosin heavy chain immunoreactivity was primarily found in the TM and calponin was primarily observed in the CM. C57BL/6 and BALB/c comparison showed that pigment obscured fluorescence in the ciliary body. Conclusions Our strategy of profiling contractile markers distinguished mouse aqueous drainage tract structures that were otherwise indistinguishable by hematoxylin and eosin staining. The mouse TM was seen as an intervening structure between SC, a part of the conventional drainage tract, and CM, a part of the unconventional drainage tract. Our findings provide important insights into the structural and functional organization of the mouse aqueous drainage tract and a basis for exploring the role of contractility in modulating aqueous outflow. PMID:24357924

Analytical Deriving of the Field Capacity through Soil Bundle Model

NASA Astrophysics Data System (ADS)

Arnone, E.; Viola, F.; Antinoro, C.; Noto, L. V.

2015-12-01

The concept of field capacity as soil hydraulic parameter is widely used in many hydrological applications. Althought its recurring usage, its definition is not univocal. Traditionally, field capacity has been related to the amount of water that remains in the soil after the excess water has drained away and the water downward movement experiences a significant decresase. Quantifying the drainage of excess of water may be vague and several definitions, often subjective, have been proposed. These definitions are based on fixed thresholds either of time, pressure, or flux to which the field capacity condition is associated. The flux-based definition identifies the field capacity as the soil moisture value corresponding to an arbitrary fixed threshold of free drainage flux. Recently, many works have investigated the flux-based definition by varying either the drainage threshold, the geometry setting and mainly the description of the drainage flux. Most of these methods are based on the simulation of the flux through a porous medium by using the Darcy's law or Richard's equation. Using the above-mentioned flux-based definition, in this work we propose an alternative analytical approach for deriving the field capacity based on a bundle-of-tubes model. The pore space of a porous medium is conceptualized as a bundle of capillary tubes of given length of different radii, derived from a known distribution. The drainage from a single capillary tube is given by the analytical solution of the differential equation describing the water height evolution within the capillary tube. This equation is based on the Poiseuille's law and describes the drainage flux with time as a function of tube radius. The drainage process is then integrated for any portion of soil taking into account the tube radius distribution which in turns depends on the soil type. This methodology allows to analytically derive the dynamics of drainage water flux for any soil type and consequently to define the soil field capacity as the latter reachs a given threshold value. The theoretical model also accounts for the tortuosity which characterizes the water pathways in real soils, but neglects the voids mutual interconnections.

Flood-frequency prediction methods for unregulated streams of Tennessee, 2000

USGS Publications Warehouse

Law, George S.; Tasker, Gary D.

2003-01-01

Up-to-date flood-frequency prediction methods for unregulated, ungaged rivers and streams of Tennessee have been developed. Prediction methods include the regional-regression method and the newer region-of-influence method. The prediction methods were developed using stream-gage records from unregulated streams draining basins having from 1 percent to about 30 percent total impervious area. These methods, however, should not be used in heavily developed or storm-sewered basins with impervious areas greater than 10 percent. The methods can be used to estimate 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence-interval floods of most unregulated rural streams in Tennessee. A computer application was developed that automates the calculation of flood frequency for unregulated, ungaged rivers and streams of Tennessee. Regional-regression equations were derived by using both single-variable and multivariable regional-regression analysis. Contributing drainage area is the explanatory variable used in the single-variable equations. Contributing drainage area, main-channel slope, and a climate factor are the explanatory variables used in the multivariable equations. Deleted-residual standard error for the single-variable equations ranged from 32 to 65 percent. Deleted-residual standard error for the multivariable equations ranged from 31 to 63 percent. These equations are included in the computer application to allow easy comparison of results produced by the different methods. The region-of-influence method calculates multivariable regression equations for each ungaged site and recurrence interval using basin characteristics from 60 similar sites selected from the study area. Explanatory variables that may be used in regression equations computed by the region-of-influence method include contributing drainage area, main-channel slope, a climate factor, and a physiographic-region factor. Deleted-residual standard error for the region-of-influence method tended to be only slightly smaller than those for the regional-regression method and ranged from 27 to 62 percent.

Comparison of Intracranial Pressure and Pressure Reactivity Index Obtained Through Pressure Measurements in the Ventricle and in the Parenchyma During and Outside Cerebrospinal Fluid Drainage Episodes in a Manipulation-Free Patient Setting.

PubMed

Klein, Samuel Patrick; Bruyninckx, Dominike; Callebaut, Ina; Depreitere, Bart

2018-01-01

We investigated the effect of cerebrospinal fluid (CSF) drainage on the intracranial pressure (ICP) signal measured in the parenchyma and the ventricle as well as the effect on the pressure reactivity index (PRx) calculated from both signals.  Ten patients were included in this prospective study. All patients received a parenchymal ICP sensor and an external ventricular drain (EVD) for CSF drainage. ICP signals (ICP-p and ICP-evd) were captured. Part of the study was a period of 90 min during which the patient was free from any manipulation, consisting of 30 min of drainage (O1), 30 min EVD closed (C) and 30 min of drainage (O2).  Mean ICP-evd and mean AMP-evd increased (3.03 and 0.46 mmHg) from O1 to C and decreased (2.12 and 0.43 mmHg) from C to O2. ICP-p and AMP-p changes were less pronounced (closing EVD: +0.81 mmHg/+0.22 mmHg; opening EVD: -0.22 mmHg/-0.05 mmHg). Mean difference between PRx-evd and PRx-p was 0.12 for O1, 0.02 for C and -0.02 for O2. The intraclass correlation coefficient for absolute agreement of single measures was 0.66 for O1, 0.77 for C and 0.69 for O2. Mean PRx differences demonstrated a significant difference between O1 versus C and O1 versus O2 but not between C versus O2.  Drainage of CSF reduces ICP magnitude and amplitude through the EVD. This effect was only marginal in parenchymal ICP measurements. In manipulation-free circumstances, agreement of PRx obtained through parenchymal and ventricular measurements was moderate to good, depending on the statistical method, and was not necessarily influenced by drainage.

Comparison of anti-siphon devices-how do they affect CSF dynamics in supine and upright posture?

PubMed

Gehlen, Manuel; Eklund, Anders; Kurtcuoglu, Vartan; Malm, Jan; Schmid Daners, Marianne

2017-08-01

Three different types of anti-siphon devices (ASDs) have been developed to counteract siphoning-induced overdrainage in upright posture. However, it is not known how the different ASDs affect CSF dynamics under the complex pressure environment seen in clinic due to postural changes. We investigated which ASDs can avoid overdrainage in upright posture best without leading to CSF accumulation. Three shunts each of the types Codman Hakim with SiphonGuard (flow-regulated), Miethke miniNAV with proSA (gravitational), and Medtronic Delta (membrane controlled) were tested. The shunts were compared on a novel in vitro setup that actively emulates the physiology of a shunted patient. This testing method allows determining the CSF drainage rates, resulting CSF volume, and intracranial pressure in the supine, sitting, and standing posture. The flow-regulated ASDs avoided increased drainage by closing their primary flow path when drainage exceeded 1.39 ± 0.42 mL/min. However, with intraperitoneal pressure increased in standing posture, we observed reopening of the ASD in 3 out of 18 experiment repetitions. The adjustable gravitational ASDs allow independent opening pressures in horizontal and vertical orientation, but they did not provide constant drainage in upright posture (0.37 ± 0.03 mL/min and 0.26 ± 0.03 mL/min in sitting and standing posture, respectively). Consequently, adaptation to the individual patient is critical. The membrane-controlled ASDs stopped drainage in upright posture. This eliminates the risk of overdrainage, but leads to CSF accumulation up to the volume observed without shunting when the patient is upright. While all tested ASDs reduced overdrainage, their actual performance will depend on a patient's specific needs because of the large variation in the way the ASDs influence CSF dynamics: while the flow-regulated shunts provide continuous drainage in upright posture, the gravitational ASDs allow and require additional adaptation, and the membrane-controlled ASDs show robust siphon prevention by a total stop of drainage.

Effects of Consumptive Water Use on Biodiversity in Wetlands of International Importance

PubMed Central

2013-01-01

Wetlands are complex ecosystems that harbor a large diversity of species. Wetlands are among the most threatened ecosystems on our planet, due to human influences such as conversion and drainage. We assessed impacts from water consumption on the species richness of waterbirds, nonresidential birds, water-dependent mammals, reptiles and amphibians in wetlands, considering a larger number of taxa than previous life cycle impact assessment methods. Effect factors (EF) were derived for 1184 wetlands of international importance. EFs quantify the number of global species-equivalents lost per m2 of wetland area loss. Vulnerability and range size of species were included to reflect conservation values. Further, we derived spatially explicit characterization factors (CFs) that distinguish between surface water and groundwater consumption. All relevant watershed areas that are contributing to feeding the respective wetlands were determined for CF applications. In an example of rose production, we compared damages of water consumption in Kenya and The Netherlands. In both cases, the impact was largest for waterbirds. The total impact from water consumption in Kenya was 67 times larger than in The Netherlands, due to larger species richness and species’ vulnerability in Kenya, as well as more arid conditions and larger amounts of water consumed. PMID:24087849

Effects of consumptive water use on biodiversity in wetlands of international importance.

PubMed

Verones, Francesca; Saner, Dominik; Pfister, Stephan; Baisero, Daniele; Rondinini, Carlo; Hellweg, Stefanie

2013-01-01

Wetlands are complex ecosystems that harbor a large diversity of species. Wetlands are among the most threatened ecosystems on our planet, due to human influences such as conversion and drainage. We assessed impacts from water consumption on the species richness of waterbirds, nonresidential birds, water-dependent mammals, reptiles and amphibians in wetlands, considering a larger number of taxa than previous life cycle impact assessment methods. Effect factors (EF) were derived for 1184 wetlands of international importance. EFs quantify the number of global species-equivalents lost per m(2) of wetland area loss. Vulnerability and range size of species were included to reflect conservation values. Further, we derived spatially explicit characterization factors (CFs) that distinguish between surface water and groundwater consumption. All relevant watershed areas that are contributing to feeding the respective wetlands were determined for CF applications. In an example of rose production, we compared damages of water consumption in Kenya and The Netherlands. In both cases, the impact was largest for waterbirds. The total impact from water consumption in Kenya was 67 times larger than in The Netherlands, due to larger species richness and species' vulnerability in Kenya, as well as more arid conditions and larger amounts of water consumed.

[Prostatic abscess: diagnosis and treatment].

PubMed

Franco, A; Menéndez, V; Luque, M P; Ribal, M J; Mallafre, J M; Alcover, J; Vilana, R; Carretero, P

1996-02-01

Prostatic abscesses are an infrequent pathology, probably due to a better and early management of prostatic infections. Predisposing factors in this pathology are diabetes mellitus, urethral catheterism or manipulation, and immunodepressed states like AIDS. Nowadays, ultrasonography is an excellent diagnostic method of this pathology, and serves as a guidance of directed drainage. We present five cases in which the size of the abscess was determining in relation to the therapeutic attitude. Abscesses of less than 2 cm, measured by transrectal ultrasonography, can be evacuated by directed puncture, followed by antibiotic treatment. When the diameter of the abscess is greater than 2 cm, we realize a perineal drainage with a catheter placed with transrectal ultrasonography. Currently, TUR and other methods seems to be overcome.

Remote sensing of wet lands in irrigated areas

NASA Technical Reports Server (NTRS)

Ham, H. H.

1972-01-01

The use of airborne remote sensing techniques to: (1) detect drainage problem areas, (2) delineate the problem in terms of areal extent, depth to the water table, and presence of excessive salinity, and (3) evaluate the effectiveness of existing subsurface drainage facilities, is discussed. Experimental results show that remote sensing, as demonstrated in this study and as presently constituted and priced, does not represent a practical alternative as a management tool to presently used visual and conventional photographic methods in the systematic and repetitive detection and delineation of wetlands.

Endoscopic Drainage of >50% of Liver in Malignant Hilar Biliary Obstruction Using Metallic or Fenestrated Plastic Stents

PubMed Central

Kerdsirichairat, Tossapol; Arain, Mustafa A; Attam, Rajeev; Glessing, Brooke; Bakman, Yan; Amateau, Stuart K; Freeman, Martin L

2017-01-01

Objectives: Endoscopic drainage of complex hilar tumors has generally resulted in poor outcomes. Drainage of >50% of liver volume has been proposed as optimal, but not evaluated using long multifenestrated plastic stents (MFPS) or self-expanding metal stents (SEMS). We evaluated outcomes of endoscopic drainage of malignant hilar strictures using optimal strategy and stents, and determined factors associated with stent patency, survival, and complications. Methods: Cross-sectional study was conducted at an academic center over 5 years. MFPS (10 French or 8.5 French) or open-cell SEMS were used for palliation of unresectable malignant hilar strictures, with imaging-targeted drainage of as many sectors as needed to drain >50% of viable liver volume. Risk factors were evaluated using regression analysis. The cumulative risk was assessed using Kaplan–Meier analysis. Results: 77 patients with malignant hilar biliary strictures (median Bismuth IV) underwent targeted stenting (41 MFPS and 36 SEMS). Comparing MFPS vs. SEMS, technical success (95.1 vs. 97.2%, P=0.64), clinical success (75.6 vs. 83.3%, P=0.40), frequency of multiple stents (23/41 vs. 25/36, P=0.19), survival and adverse events were similar, but stent patency was significantly shorter (P<0.0001). Factors associated with survival were Karnofsky score and serum bilirubin level at presentation. Outcomes were independent of Bismuth class with acceptable results in Bismuth III and IV. Conclusions: Endoscopic biliary drainage with MFPS or open-cell SEMS targeting >50% of viable liver resulted in effective palliation in patients with complex malignant hilar biliary strictures. Patency was shorter in the MFPS group, but similar survival and complications were found when comparing MFPS and SEMS group. PMID:28858292

Recovery of iron oxides from acid mine drainage and their application as adsorbent or catalyst.

PubMed

Flores, Rubia Gomes; Andersen, Silvia Layara Floriani; Maia, Leonardo Kenji Komay; José, Humberto Jorge; Moreira, Regina de Fatima Peralta Muniz

2012-11-30

Iron oxide particles recovered from acid mine drainage represent a potential low-cost feedstock to replace reagent-grade chemicals in the production of goethite, ferrihydrite or magnetite with relatively high purity. Also, the properties of iron oxides recovered from acid mine drainage mean that they can be exploited as catalysts and/or adsorbents to remove azo dyes from aqueous solutions. The main aim of this study was to recover iron oxides with relatively high purity from acid mine drainage to act as a catalyst in the oxidation of dye through a Fenton-like mechanism or as an adsorbent to remove dyes from an aqueous solution. Iron oxides (goethite) were recovered from acid mine drainage through a sequential precipitation method. Thermal treatment at temperatures higher than 300 °C produces hematite through a decrease in the BET area and an increase in the point of zero charge. In the absence of hydrogen peroxide, the solids adsorbed the textile dye Procion Red H-E7B according to the Langmuir model, and the maximum amount adsorbed decreased as the temperature of the thermal treatment increased. The decomposition kinetics of hydrogen peroxide is dependent on the H(2)O(2) concentration and iron oxides dosage, but the second-order rate constant normalized to the BET surface area is similar to that for different iron oxides tested in this and others studies. These results indicate that acid mine drainage could be used as a source material for the production of iron oxide catalysts/adsorbents, with comparable quality to those produced using analytical-grade reagents. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effects of pleural fluid drainage on respiratory function in mechanically ventilated patients after cardiac surgery

PubMed Central

Brims, Fraser J H; Davies, Michael G; Elia, Andy; Griffiths, Mark J D

2015-01-01

Background Pleural effusions occur commonly after cardiac surgery and the effects of drainage on gas exchange in this population are not well established. We examined pulmonary function indices following drainage of pleural effusions in cardiac surgery patients. Methods We performed a retrospective study examining the effects of pleural fluid drainage on the lung function indices of patients recovering from cardiac surgery requiring mechanical ventilation for more than 7 days. We specifically analysed patients who had pleural fluid removed via an intercostal tube (ICT: drain group) compared with those of a control group (no effusion, no ICT). Results In the drain group, 52 ICTs were sited in 45 patients. The mean (SD) volume of fluid drained was 1180 (634) mL. Indices of oxygenation were significantly worse in the drain group compared with controls prior to drainage. The arterial oxygen tension (PaO2)/fractional inspired oxygen (FiO2) (P/F) ratio improved on day 1 after ICT placement (mean (SD), day 0: 31.01 (8.92) vs 37.18 (10.7); p<0.05) and both the P/F ratio and oxygenation index (OI: kPa/cm H2O=PaO2/mean airway pressure×FiO2) demonstrated sustained improvement to day 5 (P/F day 5: 39.85 (12.8); OI day 0: 2.88 (1.10) vs day 5: 4.06 (1.73); both p<0.01). The drain group patients were more likely to have an improved mode of ventilation on day 1 compared with controls (p=0.028). Conclusions Pleural effusion after cardiac surgery may impair oxygenation. Drainage of pleural fluid is associated with a rapid and sustained improvement in oxygenation. PMID:26339492

Utility of 222Rn as a passive tracer of subglacial distributed system drainage

NASA Astrophysics Data System (ADS)

Linhoff, Benjamin S.; Charette, Matthew A.; Nienow, Peter W.; Wadham, Jemma L.; Tedstone, Andrew J.; Cowton, Thomas

2017-03-01

Water flow beneath the Greenland Ice Sheet (GrIS) has been shown to include slow-inefficient (distributed) and fast-efficient (channelized) drainage systems, in response to meltwater delivery to the bed via both moulins and surface lake drainage. This partitioning between channelized and distributed drainage systems is difficult to quantify yet it plays an important role in bulk meltwater chemistry and glacial velocity, and thus subglacial erosion. Radon-222, which is continuously produced via the decay of 226Ra, accumulates in meltwater that has interacted with rock and sediment. Hence, elevated concentrations of 222Rn should be indicative of meltwater that has flowed through a distributed drainage system network. In the spring and summer of 2011 and 2012, we made hourly 222Rn measurements in the proglacial river of a large outlet glacier of the GrIS (Leverett Glacier, SW Greenland). Radon-222 activities were highest in the early melt season (10-15 dpm L-1), decreasing by a factor of 2-5 (3-5 dpm L-1) following the onset of widespread surface melt. Using a 222Rn mass balance model, we estimate that, on average, greater than 90% of the river 222Rn was sourced from distributed system meltwater. The distributed system 222Rn flux varied on diurnal, weekly, and seasonal time scales with highest fluxes generally occurring on the falling limb of the hydrograph and during expansion of the channelized drainage system. Using laboratory based estimates of distributed system 222Rn, the distributed system water flux generally ranged between 1-5% of the total proglacial river discharge for both seasons. This study provides a promising new method for hydrograph separation in glacial watersheds and for estimating the timing and magnitude of distributed system fluxes expelled at ice sheet margins.

Determination of the Thermal Properties of Sands as Affected by Water Content, Drainage/Wetting, and Porosity Conditions for Sands With Different Grain Sizes

NASA Astrophysics Data System (ADS)

Smits, K. M.; Sakaki, T.; Limsuwat, A.; Illangasekare, T. H.

2009-05-01

It is widely recognized that liquid water, water vapor and temperature movement in the subsurface near the land/atmosphere interface are strongly coupled, influencing many agricultural, biological and engineering applications such as irrigation practices, the assessment of contaminant transport and the detection of buried landmines. In these systems, a clear understanding of how variations in water content, soil drainage/wetting history, porosity conditions and grain size affect the soil's thermal behavior is needed, however, the consideration of all factors is rare as very few experimental data showing the effects of these variations are available. In this study, the effect of soil moisture, drainage/wetting history, and porosity on the thermal conductivity of sandy soils with different grain sizes was investigated. For this experimental investigation, several recent sensor based technologies were compiled into a Tempe cell modified to have a network of sampling ports, continuously monitoring water saturation, capillary pressure, temperature, and soil thermal properties. The water table was established at mid elevation of the cell and then lowered slowly. The initially saturated soil sample was subjected to slow drainage, wetting, and secondary drainage cycles. After liquid water drainage ceased, evaporation was induced at the surface to remove soil moisture from the sample to obtain thermal conductivity data below the residual saturation. For the test soils studied, thermal conductivity increased with increasing moisture content, soil density and grain size while thermal conductivity values were similar for soil drying/wetting behavior. Thermal properties measured in this study were then compared with independent estimates made using empirical models from literature. These soils will be used in a proposed set of experiments in intermediate scale test tanks to obtain data to validate methods and modeling tools used for landmine detection.

Measurement of peak CSF flow velocity at cerebral aqueduct, before and after lumbar CSF drainage, by use of phase-contrast MRI: utility in the management of idiopathic normal pressure hydrocephalus.

PubMed

Sharma, Ashwani Kumar; Gaikwad, Shailesh; Gupta, Vipul; Garg, Ajay; Mishra, Nalini K

2008-04-01

Since it was first described, normal pressure hydrocephalus (NPH) and its treatment by means of cerebrospinal fluid (CSF) shunting have been the focus of much investigation. Whatever be the cause of NPH, it has been hypothesized that in this disease there occurs decreased arterial expansion and an increased brain expansion leading to increased transmantle pressure. We cannot measure the latter, but fortunately the effect of these changes (increased peak flow velocity through the aqueduct) can be quantified with cine phase-contrast magnetic resonance imaging (MRI). This investigation was thus undertaken to characterize and measure CSF peak flow velocity at the level of the aqueduct, before and after lumbar CSF drainage, by means of a phase-contrast cine MRI and determine its role in selecting cases for shunt surgery. 37 patients with clinically suspected NPH were included in the study. Changes in the hyperdynamic peak CSF flow velocity with 50 ml lumbar CSF drainage (mimicking shunt) were evaluated in them for considering shunt surgery. 14 out of 15 patients who were recommended for shunt surgery, based on changes peak flow velocity after lumbar CSF drainage, improved after shunt surgery. None of the cases which were not recommended for shunt surgery, based on changes in CSF peak flow velocity after lumbar CSF drainage, improved after shunt surgery (2 out of 22 cases). The study concluded that the phase-contrast MR imaging, done before and after CSF drainage, is a sensitive method to support the clinical diagnosis of normal pressure hydrocephalus, selecting patients of NPH who are likely to benefit from shunt surgery, and to select patients of NPH who are not likely to benefit from shunt surgery.

A Specific Mapping Study Using Fluorescence Sentinel Lymph Node Detection in Patients with Intermediate- and High-risk Prostate Cancer Undergoing Extended Pelvic Lymph Node Dissection.

PubMed

Nguyen, Daniel P; Huber, Philipp M; Metzger, Tobias A; Genitsch, Vera; Schudel, Hans H; Thalmann, George N

2016-11-01

Sentinel lymph node (SLN) detection techniques have the potential to change the standard of surgical care for patients with prostate cancer. We performed a lymphatic mapping study and determined the value of fluorescence SLN detection with indocyanine green (ICG) for the detection of lymph node metastases in intermediate- and high-risk patients undergoing radical prostatectomy and extended pelvic lymph node dissection. A total of 42 patients received systematic or specific ICG injections into the prostate base, the midportion, the apex, the left lobe, or the right lobe. We found (1) that external and internal iliac regions encompass the majority of SLNs, (2) that common iliac regions contain up to 22% of all SLNs, (3) that a prostatic lobe can drain into the contralateral group of pelvic lymph nodes, and (4) that the fossa of Marcille also receives significant drainage. Among the 12 patients who received systematic ICG injections, 5 (42%) had a total of 29 lymph node metastases. Of these, 16 nodes were ICG positive, yielding 55% sensitivity. The complex drainage pattern of the prostate and the low sensitivity of ICG for the detection of lymph node metastases reported in our study highlight the difficulties related to the implementation of SNL techniques in prostate cancer. There is controversy about how extensive lymph node dissection (LND) should be during prostatectomy. We investigated the lymphatic drainage of the prostate and whether sentinel node fluorescence techniques would be useful to detect node metastases. We found that the drainage pattern is complex and that the sentinel node technique is not able to replace extended pelvic LND. Copyright © 2016. Published by Elsevier B.V.

Peritoneal drainage or laparotomy for neonatal bowel perforation? A randomized controlled trial.

PubMed

Rees, Clare M; Eaton, Simon; Kiely, Edward M; Wade, Angie M; McHugh, Kieran; Pierro, Agostino

2008-07-01

To determine whether primary peritoneal drainage improves survival and outcome of extremely low birth weight (ELBW) infants with intestinal perforation. Optimal surgical management of ELBW infants with intestinal perforation is unknown. An international multicenter randomized controlled trial was performed between 2002 and 2006. Inclusion criteria were birthweight >or=1000 g and pneumoperitoneum on x-ray (necrotizing enterocolitis or isolated perforation). Patients were randomized to peritoneal drain or laparotomy, minimizing differences in weight, gestation, ventilation, inotropes, platelets, country, and on-site surgical facilities. Patients randomized to drain were allowed to have a delayed laparotomy after at least 12 hours of no clinical improvement. Sixty-nine patients were randomized (35 drain, 34 laparotomy); 1 subsequently withdrew consent. Six-month survival was 18/35 (51.4%) with a drain and 21/33 (63.6%) with laparotomy (P = 0.3; difference 12% 95% CI, -11, 34%). Cox regression analysis showed no significant difference between groups (hazard ratio for primary drain 1.6; P = 0.3; 95% CI, 0.7-3.4). Delayed laparotomy was performed in 26/35 (74%) patients after a median of 2.5 days (range, 0.4-21) and did not improve 6-month survival compared with primary laparotomy (relative risk of mortality 1.4; P = 0.4; 95% CI, 0.6-3.4). Drain was effective as a definitive treatment in only 4/35 (11%) surviving neonates, the rest either had a delayed laparotomy or died. Seventy-four percent of neonates treated with primary peritoneal drainage required delayed laparotomy. There were no significant differences in outcomes between the 2 randomization groups. Primary peritoneal drainage is ineffective as either a temporising measure or definitive treatment. If a drain is inserted, a timely "rescue" laparotomy should be considered. Trial registration number ISRCTN18282954; http://isrctn.org/

Prairie Pothole Region wetlands and subsurface drainage systems: Key factors for determining drainage setback distances

USGS Publications Warehouse

Tangen, Brian; Wiltermuth, Mark T.

2018-01-01

Use of agricultural subsurface drainage systems in the Prairie Pothole Region of North America continues to increase, prompting concerns over potential negative effects to the Region's vital wetlands. The U.S. Fish and Wildlife Service protects a large number of wetlands through conservation easements that often utilize standard lateral setback distances to provide buffers between wetlands and drainage systems. Because of a lack of information pertaining to the efficacy of these setback distances for protecting wetlands, information is required to support the decision making for placement of subsurface drainage systems adjacent to wetlands. We used qualitative graphical analyses and data comparisons to identify characteristics of subsurface drainage systems and wetland catchments that could be considered when assessing setback distances. We also compared setback distances with catchment slope lengths to determine if they typically exclude drainage systems from the catchment. We demonstrated that depth of a subsurface drainage system is a key factor for determining drainage setback distances. Drainage systems located closer to the surface (shallow) typically could be associated with shorter lateral setback distances compared with deeper systems. Subsurface drainage systems would be allowed within a wetland's catchment for 44–59% of catchments associated with wetland conservation easements in North Dakota. More specifically, results suggest that drainage setback distances generally would exclude drainage systems from catchments of the smaller wetlands that typically have shorter slopes in the adjacent upland contributing area. For larger wetlands, however, considerable areas of the catchment would be vulnerable to drainage that may affect wetland hydrology. U.S. Fish and Wildlife Service easements are associated with > 2,000 km2 of wetlands in North Dakota, demonstrating great potential to protect these systems from drainage depending on policies for installing subsurface drainage systems on these lands. The length of slope of individual catchments and depth of subsurface drainage systems could be considered when prescribing drainage setback distances and assessing potential effects to wetland hydrology. Moreover, because of uncertainties associated with the efficacy of standard drainage setback distances, exclusion of subsurface drainage systems from wetland catchments would be ideal when the goal is to protect wetlands.

Viscosity and stability of ultra-high internal phase CO2-in-water foams stabilized with surfactants and nanoparticles with or without polyelectrolytes.

PubMed

Xue, Zheng; Worthen, Andrew; Qajar, Ali; Robert, Isaiah; Bryant, Steven L; Huh, Chun; Prodanović, Maša; Johnston, Keith P

2016-01-01

To date, relatively few examples of ultra-high internal phase supercritical CO2-in-water foams (also referred to as macroemulsions) have been observed, despite interest in applications including "waterless" hydraulic fracturing in energy production. The viscosities and stabilities of foams up to 0.98 CO2 volume fraction were investigated in terms of foam bubble size, interfacial tension, and bulk and surface viscosity. The foams were stabilized with laurylamidopropyl betaine (LAPB) surfactant and silica nanoparticles (NPs), with and without partially hydrolyzed polyacrylamide (HPAM). For foams stabilized with mixture of LAPB and NPs, fine ∼70 μm bubbles and high viscosities on the order of 100 cP at>0.90 internal phase fraction were stabilized for hours to days. The surfactant reduces interfacial tension, and thus facilitates bubble generation and decreases the capillary pressure to reduce the drainage rate of the lamella. The LAPB, which is in the cationic protonated form, also attracts anionic NPs (and anionic HPAM in systems containing polymer) to the interface. The adsorbed NPs at the interface are shown to slow down Ostwald ripening (with or without polymer added) and increase foam stability. In systems with added HPAM, the increase in the bulk and surface viscosity of the aqueous phase further decreases the lamella drainage rate and inhibits coalescence of foams. Thus, the added polymer increases the foam viscosity by threefold. Scaling law analysis shows the viscosity of 0.90 volume fraction foams is inversely proportional to the bubble size. Copyright © 2015 Elsevier Inc. All rights reserved.

Evaluation of Streamflow Requirements for Habitat Protection by Comparison to Streamflow Characteristics at Index Streamflow-Gaging Stations in Southern New England

USGS Publications Warehouse

Armstrong, David S.; Parker, Gene W.; Richards, Todd A.

2003-01-01

Streamflow characteristics and methods for determining streamflow requirements for habitat protection were investigated at 23 active index streamflow-gaging stations in southern New England. Fish communities sampled near index streamflow-gaging stations in Massachusetts have a high percentage of fish that require flowing-water habitats for some or all of their life cycle. The relatively unaltered flow condition at these sites was assumed to be one factor that has contributed to this condition. Monthly flow durations and low flow statistics were determined for the index streamflow-gaging stations for a 25- year period from 1976 to 2000. Annual hydrographs were prepared for each index station from median streamflows at the 50-percent monthly flow duration, normalized by drainage area. A median monthly flow of 1 ft3/s/mi2 was used to split hydrographs into a high-flow period (November–May), and a low-flow period (June–October). The hydrographs were used to classify index stations into groups with similar median monthly flow durations. Index stations were divided into four regional groups, roughly paralleling the coast, to characterize streamflows for November to May; and into two groups, on the basis of base-flow index and percentage of sand and gravel in the contributing area, for June to October. For the June to October period, for index stations with a high base-flow index and contributing areas greater than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.57, 0.49, and 0.46 ft3/s/mi2 for July, August, and September, respectively. For index stations with a low base-flow index and contributing areas less than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.34, 0.28, and 0.27 ft3/s/mi2 for July, August, and September, respectively. Streamflow variability between wet and dry years can be characterized by use of the interquartile range of median streamflows at selected monthly flow durations. For example, the median Q50 discharge for August had an interquartile range of 0.30 to 0.87 ft3/s/mi2 for the high-flow group and 0.16 to 0.47 ft3/s/mi2 for the low-flow group. Streamflow requirements for habitat protection were determined for 23 index stations by use of three methods based on hydrologic records, the Range of Variability Approach, the Tennant method, and the New England Aquatic-Base-Flow method. Normalized flow management targets determined by the Range of Variability Approach for July, August, and September ranged between 0.21 and 0.84 ft3/s/mi2 for the low monthly flow duration group, and 0.37 and 1.27 ft3/s/mi2 for the high monthly flow duration group. Median streamflow requirements for habitat protection during summer for the 23 index streamflow-gaging stations determined by the Tennant method, normalized by drainage area, were 0.81, 0.61, and 0.21 ft3/s/mi2 for the Tennant 40-, 30-, and 10-percent of the mean annual flow methods, representing good, fair, and poor stream habitat conditions in summer, according to Tennant. New England Aquatic-Base-Flow streamflow requirements for habitat protection during summer were determined from median of monthly mean flows for August for index streamflow-gaging stations having drainage areas greater than 50 mi2 . For five index streamflow-gaging stations in the low median monthly flow group, the average median monthly mean streamflow for August, normalized by drainage area, was 0.48 ft3/s/mi2. Streamflow requirements for habitat protection were determined for riffle habitats near 10 index stations by use of two methods based on hydraulic ratings, the Wetted-Perimeter and R2Cross methods. Hydraulic parameters required by these methods were simulated by calibrated HEC-RAS models. Wetted-Perimeter streamflow requirements for habitat protection, normalized by drainage area, ranged between 0.13 and 0.58 ft3/s/mi2, and had a median value of 0.37 ft3/s/mi2. Streamflow requirements determined by the R2Cross 3-of-3 criteria method ranged between 0.39 and 2.1 ft3/s/mi2 , and had a median of 0.84 ft3/s/mi2. Streamflow requirements determined by the R2Cross 2-of-3 criteria method, normalized by drainage area, ranged between 0.16 and 0.85 ft3/s/mi2 and had a median of 0.36 ft3/s/mi2 , respectively. Streamflow requirements determined by the different methods were evaluated by comparison to streamflow statistics from the index streamflow-gaging stations.

Drilling skull plus injection of urokinase in the treatment of epidural haematoma: a preliminary study.

PubMed

Liu, Weiguo; Ma, Li; Wen, Liang; Shen, Fang; Sheng, Hansong; Zhou, Bo; Hu, Weiwei; Zheng, Xiujue; Yang, Xiaofeng

2008-02-01

This study was performed to evaluate the effectiveness of a minimally invasive approach to manage patients with epidural haematoma (EDH). The surgical indication and key points were investigated. Descriptive, retrospective study. Twenty-one patients with traumatic EDH were treated through the following method: After anaesthesia, twist drill trepanations were performed followed by a placement of drainage tubes. Twenty ku urokinase in 3 ml saline was injected into the haematoma cyst through the tube, which was closed for 3 hours before connection to a vacuum ball with negative pressure. The injection was repeated three times a day after operation. The fibrinolytic agents were not used in the 'acute group' because of the risk of rebleeding. CT scans were performed according to the changes of clinical manifestations. The drainage tubes were left for 3-5 days before most clots were resolved. The patients discharged after 7 days' hospitalization on average. No infections or recurrence of EDHs were observed in this series. Drilling skull plus injection of urokinase through drainage tube is a safe and effective method with less injury in the treatment of a selected part of patients with EDHs.

[Choice of urinary tract drainage in different age groups of patients with urolithiasis].

PubMed

Trapeznikova, M F; Dutov, V V; Rumiantsev, A A; Rusanova, E V; Zlobin, A N; Beliaev, V V

2011-01-01

Retro- and prospective analyses of 802 case histories of patients with nephrostomic drainage (n=272), ureteral catheter (n=27) and ureteral stent (n=503) treated for urolithiasis in the urological department of M.F. Vladimirsky Moscow Region Research Clinical Institute and Zhukovsky city hospital hospitalized in 1995 to 2009 made it possible to develop algorithms of choice of upper urinary tract drainage depending on clinical and laboratory indices. Nephrostomic drainage is preferable in a single functioning kidney, acute obstructive pyelonephritis, anuria, hyperthermia above 38 degrees C, marked supravesical urodynamic disorder, in renal failure, serum creatinine over 200 mcmol/l, urea over 10 mmol/l, blood potassium over 5 mmol/l, uric acid over 380 mcmol/l and leukocytosis over 8 x 10(9) l. Draining with ureteral stent was used primarily in elective surgery--extracorporeal shock-wave lithotripsy and transurethral operations. Stenting was better tolerated and entailed less frequent complications. In the rest cases choice of drain method should be made by the urologist. In active inflammation, before getting antibioticogram, the drain should be followed by antibiotic treatment with fluoroquinolones, cephalosporines of the third or forth generation, aminoglycosides, carbapenems in standard doses.

Estimating restorable wetland water storage at landscape scales

USGS Publications Warehouse

Jones, Charles Nathan; Evenson, Grey R.; McLaughlin, Daniel L.; Vanderhoof, Melanie; Lang, Megan W.; McCarty, Greg W.; Golden, Heather E.; Lane, Charles R.; Alexander, Laurie C.

2018-01-01

Globally, hydrologic modifications such as ditching and subsurface drainage have significantly reduced wetland water storage capacity (i.e., volume of surface water a wetland can retain) and consequent wetland functions. While wetland area has been well documented across many landscapes and used to guide restoration efforts, few studies have directly quantified the associated wetland storage capacity. Here, we present a novel raster-based approach to quantify both contemporary and potential (i.e., restorable) storage capacities of individual depressional basins across landscapes. We demonstrate the utility of this method by applying it to the Delmarva Peninsula, a region punctuated by both depressional wetlands and drainage ditches. Across the entire peninsula, we estimated that restoration (i.e., plugging ditches) could increase storage capacity by 80%. Focusing on an individual watershed, we found that over 59% of restorable storage capacity occurs within 20 m of the drainage network, and that 93% occurs within 1 m elevation of the drainage network. Our demonstration highlights widespread ditching in this landscape, spatial patterns of both contemporary and potential storage capacities, and clear opportunities for hydrologic restoration. In Delmarva and more broadly, our novel approach can inform targeted landscape-scale conservation and restoration efforts to optimize hydrologically mediated wetland functions.

Estimating restorable wetland water storage at landscape scales.

PubMed

Jones, Charles Nathan; Evenson, Grey R; McLaughlin, Daniel L; Vanderhoof, Melanie K; Lang, Megan W; McCarty, Greg W; Golden, Heather E; Lane, Charles R; Alexander, Laurie C

2018-01-01

Globally, hydrologic modifications such as ditching and subsurface drainage have significantly reduced wetland water storage capacity (i.e., volume of surface water a wetland can retain) and consequent wetland functions. While wetland area has been well documented across many landscapes and used to guide restoration efforts, few studies have directly quantified the associated wetland storage capacity. Here, we present a novel raster-based approach to quantify both contemporary and potential (i.e., restorable) storage capacities of individual depressional basins across landscapes. We demonstrate the utility of this method by applying it to the Delmarva Peninsula, a region punctuated by both depressional wetlands and drainage ditches. Across the entire peninsula, we estimated that restoration (i.e., plugging ditches) could increase storage capacity by 80%. Focusing on an individual watershed, we found that over 59% of restorable storage capacity occurs within 20 m of the drainage network, and that 93% occurs within 1 m elevation of the drainage network. Our demonstration highlights widespread ditching in this landscape, spatial patterns of both contemporary and potential storage capacities, and clear opportunities for hydrologic restoration. In Delmarva and more broadly, our novel approach can inform targeted landscape-scale conservation and restoration efforts to optimize hydrologically mediated wetland functions.

A stochastic approach for automatic generation of urban drainage systems.

PubMed

Möderl, M; Butler, D; Rauch, W

2009-01-01

Typically, performance evaluation of new developed methodologies is based on one or more case studies. The investigation of multiple real world case studies is tedious and time consuming. Moreover extrapolating conclusions from individual investigations to a general basis is arguable and sometimes even wrong. In this article a stochastic approach is presented to evaluate new developed methodologies on a broader basis. For the approach the Matlab-tool "Case Study Generator" is developed which generates a variety of different virtual urban drainage systems automatically using boundary conditions e.g. length of urban drainage system, slope of catchment surface, etc. as input. The layout of the sewer system is based on an adapted Galton-Watson branching process. The sub catchments are allocated considering a digital terrain model. Sewer system components are designed according to standard values. In total, 10,000 different virtual case studies of urban drainage system are generated and simulated. Consequently, simulation results are evaluated using a performance indicator for surface flooding. Comparison between results of the virtual and two real world case studies indicates the promise of the method. The novelty of the approach is that it is possible to get more general conclusions in contrast to traditional evaluations with few case studies.

The Rare Perennial Balduina atropurpurea (Asteraceae) at Fort Stewart, Georgia

DTIC Science & Technology

1998-06-01

savannas; moist, sandy, peaty clearings among slash ( Pinus elliottii) and longleaf (P. palustris) pines; and sandhill seeps with seasonal standing...with relatively shallow roots; however, near the end of the autumn drought these soils are still wet. It is believed that the soils remain wet from...internal drainage through the upland soils above the impervious clay layer into the topographically lower bog habitats over the 6 to 8 week drought

Enhancement of venous drainage with vein stripper for reversed pedicled neurocutaneous flaps.

PubMed

Sonmez, Erhan; Silistireli, Özlem Karataş; Karaaslan, Önder; Kamburoğlu, Haldun Onuralp; Safak, Tunc

2013-05-01

The flaps based on the vascular axis of superficial sensitive cutaneous nerves had gained increased popularity in reconstructive surgery because of such major advantages as preservation of major extremity arteries and avoidance of microsurgical procedures. However, postoperative venous congestion resulting in partial or total necrosis is still a common problem for these flaps. The aim of the current study is to introduce a new method for reducing the postoperative venous congestion of neural island flap with the results of reconstruction of the soft tissue defects of foot and ankle. This method was used to treat 19 patients with various chronic soft tissue defects of the foot and ankle between 2011 and 2012. We observed that the novel method presented in this report enables effective venous drainage, solving the postoperative venous congestion problem of these flaps. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Pelvic drainage during removal of dialysis catheter decreases the risk of subsequent intra-abdominal complications in refractory peritoneal dialysis-related peritonitis.

PubMed

Hsu, Chih-Yang; Huang, Wei-Chieh; Huang, Chun-Kai; Huang, Chien-Wei; Chou, Nan-Hua; Lee, Po-Tsang; Fang, Hua-Chang; Chou, Kang-Ju; Chen, Chien-Liang

2015-11-01

Some patients with refractory peritoneal dialysis-related peritonitis continue to develop intra-abdominal complications despite removal of the peritoneal catheter. Repeated percutaneous drainage or open laparotomy is often required, and mortality is not uncommon. The benefits of pelvic drainage placement during catheter removal in decreasing these complications and interventions remain unproven. Forty-six patients with refractory peritonitis who underwent removal of a Tenckhoff catheter between 1991 and 2013 were reviewed retrospectively. Twelve patients had pelvic drainage using closed active suction devices during catheter removal (drainage group). The remaining 34 patients underwent catheter removal without drainage (non-drainage group). The outcomes measured were the development of intra-abdominal complications and the requirement for repeated percutaneous drainage or open laparotomy within 90 days after the catheter removal. Baseline characteristics were similar with the exception of a higher median number of previous peritonitis episodes in the drainage group compared with the non-drainage group (2 vs 0, P = 0.02). During the follow-up period, intra-abdominal complications occurred in 15 (44%) of 34 patients in the non-drainage group, compared with one (8%) of 12 patients in the drainage group (P = 0.03). Twelve (35%) patients in the non-drainage group required repeated percutaneous drainage or open laparotomy for management, compared with zero (0%) patients in the drainage group (P = 0.02). Drain tubes were removed at a median of 6 days (inter-quartile range: 5-10) without complications. In the management of refractory peritonitis, pelvic drainage during removal of dialysis catheter decreases the risk of subsequent intra-abdominal complications and invasive interventions. © 2015 Asian Pacific Society of Nephrology.

A prospective, multicenter study of a double stent system for palliative treatment of malignant extrahepatic biliary obstructions.

PubMed

Kim, Jong Woo; Gwon, Dong Il; Han, Young-Min; Won, Je Hwan; Hong, Hyun Pyo; Ko, Gi-Young; Yoon, Hyun-Ki; Sung, Kyu-Bo

2015-10-01

A double stent system (covered stent in uncovered stent) was designed to provide long-term patency without tumor ingrowth or stent-related complications, such as stent migration, cholecystitis, or pancreatitis. To investigate the safety and efficacy of double stents in patients with malignant extrahepatic biliary obstructions. This prospective, nonrandomized, multicenter study enrolled 160 consecutive patients (102 men; mean age, 64 years; range, 33-91 years) with malignant extrahepatic biliary obstructions treated with a double stent system from January 2010 to March 2012. The technical success rate of the double stent placement was 100%. No stent migration was observed. Procedure-related minor (self-limiting hemobilia [n = 6] and cholangitis [n = 2]) and major (pancreatitis [n = 16], cholecystitis [n = 3], and hepatic abscess [n = 2]) complications occurred in a total of 29 patients. The mean serum bilirubin level, which was 8.9 ± 5.6 mg/dL before drainage, decreased to 2.2 ± 4.6 mg/dL 1 month after stent placement (P < 0.001). Successful internal drainage was achieved in 148 patients (92.5%). During the mean follow-up period of 205 days, acute cholecystitis (n = 3) and hepatic abscess (n = 2) occurred in five patients. The median patient survival and stent patency time were 135 days (95% confidence interval [CI], 96-160 days) and 114 days (95% CI, 83-131 days), respectively. Of 153 patients, 22 (14.4%) presented with stent dysfunction due to sludge incrustation (n = 17), tumor overgrowth (n = 4), or blood clot (n = 1), and required repeat intervention. Tumor ingrowth was not observed in any of these patients. Percutaneous treatment of malignant extrahepatic biliary obstruction using a double stent safely and effectively achieves internal biliary drainage. © The Foundation Acta Radiologica 2014.

An Optimal Balance between Efficiency and Safety of Urban Drainage Networks

NASA Astrophysics Data System (ADS)

Seo, Y.

2014-12-01

Urban drainage networks have been developed to promote the efficiency of a system in terms of drainage time so far. Typically, a drainage system is designed to drain water from developed areas promptly as much as possible during floods. In this regard, an artificial drainage system have been considered to be more efficient compared to river networks in nature. This study examined artificial drainage networks and the results indicate they can be less efficient in terms of network configuration compared with river networks, which is counter-intuitive. The case study of 20 catchments in Seoul, South Korea shows that they have wide range of efficiency in terms of network configuration and consequently, drainage time. This study also demonstrates that efficient drainage networks are more sensitive to spatial and temporal rainfall variation such as rainstorm movement. Peak flows increase more than two times greater in effective drainage networks compared with inefficient and highly sinuous drainage networks. Combining these results, this study implies that the layout of a drainage network is an important factor in terms of efficient drainage and also safety in urban catchments. Design of an optimal layout of the drainage network can be an alternative non-structural measures that mitigate potential risks and it is crucial for the sustainability of urban environments.

Controlling Bottom Hole Flowing Pressure Within a Specific Range for Efficient Coalbed Methane Drainage

NASA Astrophysics Data System (ADS)

Zhao, Bin; Wang, Zhi-Yin; Hu, Ai-Mei; Zhai, Yu-Yang

2013-11-01

The stress state of coal surrounding a coalbed methane (CBM) production well is affected by the bottom hole flowing pressure (BHFP). The permeability of coal shows a marked change under compression. The BHFP must be restricted to a specific range to favor higher permeability in the surrounding coal and thus higher productivity of the well. A new method to determine this specific range is proposed in this paper. Coal has a rather low tensile strength, which induces tensile failure and rock disintegration. The deformation of coal samples under compression has four main stages: compaction, elastic deformation, strain hardening, and strain softening. Permeability is optimal when the coal samples are in the strain softening stage. The three critical values of BHFP, namely, p wmin, p wmid, and p wupper, which correspond to the occurrence of tensile failure, the start of strain softening, and the beginning of plastic deformation, respectively, are derived from theoretical principles. The permeability of coal is in an optimal state when the BHFP is between p wmin and p wmid. The BHFP should be confined to this specific range for the efficient drainage of CBM wells. This method was applied to field operations in three wells in the Hancheng CBM field in China. A comprehensive analysis of drainage data and of the BHFP indicates that the new method is effective and offers significant improvement to current practices.

Representing natural and manmade drainage systems in an earth system modeling framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hongyi; Wu, Huan; Huang, Maoyi

Drainage systems can be categorized into natural or geomorphological drainage systems, agricultural drainage systems and urban drainage systems. They interact closely among themselves and with climate and human society, particularly under extreme climate and hydrological events such as floods. This editorial articulates the need to holistically understand and model drainage systems in the context of climate change and human influence, and discusses the requirements and examples of feasible approaches to representing natural and manmade drainage systems in an earth system modeling framework.

Effect Of Preoperative Intravenous Steroids On Seroma Formation After Modified Radical Mastectomy.

PubMed

Khan, Maryam Alam

2017-01-01

With the steep increase in breast cancer incidence globally and regionally, there has been a trend toward reducing patient morbidity by meticulous surgical techniques to obviate complications like seroma formation; use to pre-operative steroids seems to be convenient, cost effective and shows promising results in trials. This randomized clinical trial was conducted at Surgical Department of Khyber Teaching Hospital Peshawar, from January 2012 to April 2014 on 65 patients randomly allocated to Group A and Group B using lottery method. Group A underwent MRM+AD in the conventional manner while Group B received a 120 mg of injection Depomedrol intravenously 1 hour before the surgery. The two were compared in terms of total drainage, days of drainage, wound complications and incidence of seroma. Data was entered and analysed using statistical program SPSS-21. The mean age in group A was 34.2±10.1 years and B was 32.3±9.1 years. The mean drainage in intervention group was significantly reduced as compared to control group (755.4±65ml vs 928.3±102.5). Total drainage days were reduced (6.5±1.6 days vs 10.2±2.2 days) and incidence of seroma was also reduced (A=18.75% vs B=6.06%). However, three patients in group B had wound infection. Seroma formation is the most common complication of Mastectomy and among the methods used to reduce its incidence, steroid administration seems to be the most cost effective and shows promising results.

Twist-Drill or Burr Hole Craniostomy for Draining Chronic Subdural Hematomas: How to Choose It for Chronic Subdural Hematoma Drainage.

PubMed

Lee, Seong-Jong; Hwang, Sun-Chul; Im, Soo Bin

2016-10-01

Although twist-drill craniostomy (TDC) has a number of procedural advantages and an equivalent outcome compared to burr hole craniostomy (BHC) for the treatment of chronic subdural hematomas (CSDHs), the latter technique remains the preferred method. We analyzed symptomatic CSDHs in whom TDC at the pre-coronal suture entry point (PCSEP) was the primary method for hematoma drainage and BHC on the parietal was the secondary option. CSDHs in 86 consecutive patients were included. TDC at the PCSEP, which is 1 cm anterior to coronal suture at the level of the superior temporal line, was the primary operational technique when the hematoma thickness was suitable, and BHC was performed via the parietal when TDC was unreasonable or failed. The clinical feasibility and outcomes of these approaches were analyzed. Of the 86 patients, 68 (79.1%) were treated by TDC, and 18 (20.9%) by BHC. All patients showed improvements in their symptoms after hematoma drainage. Neither morbidity nor mortality was associated with either technique, and there were no differences in drainage days between the groups. Ten patients had bilateral hematomas and were treated using TDC. Two patients were not sufficiently treated by TDC and, as a result, BHC was applied. Only six hematomas (7% of 86 hematomas) exhibited insufficient thickness on the computed tomography to perform TDC. When the hematoma was thick enough, a majority of the CSDHs were drained using TDC at the PCSEP as the first procedure, which was especially useful for bilateral hematomas and in elderly patients.

An Automated, Gravity-driven CSF Drainage System Decreases Complications and Lowers Costs

PubMed Central

Lieberson, Robert E; Meyer, William; Trang, Tung

2017-01-01

Background: FlowSafeTM (BeckerSmith Medical, Irvine, CA, USA) is a novel, robotic, external lumbar drainage (ELD) system, which was designed to control cerebrospinal fluid (CSF) drainage, reduce complications, and decrease treatment costs. Methods: Forty-seven consecutive neurosurgical patients requiring ELD were treated using the FlowSafe system. Results: In 39 of 40 patients with traumatic and surgical dural openings, potential CSF leaks were avoided. In seven patients with suspected normal pressure hydrocephalus, post-infectious ventriculomegaly, or pseudotumor cerebrum, we were able to assess the likelihood of improvement with shunting. The system, therefore, produced what we considered to be the “desired result” in 46 of 47 patients (98%). Our one treatment failure (2%) involved a patient with unrecognized hydrocephalus who, following a Chiari repair with a dural patch graft, was drained for six days. A persistent CSF leak eventually required a reoperation. Two patients (4%) described low-pressure headaches during treatment. Both responded to temporarily suspending or reducing the drainage rate. We saw no complications. Required nursing interventions were minimal.  Conclusions: The FlowSafe system was safe and effective. In our experience, there were fewer complications compared to currently available ELD systems. The FlowSafe was well tolerated by our patients. The near elimination of nursing interventions should allow lumbar drainage to be delivered in less costly, non-intensive care unit settings. Larger trials will be needed. PMID:28331772

Impairment of Lymph Drainage in Subfascial Compartment of Forearm in Breast Cancer-Related Lymphedema

PubMed Central

MELLOR, R.H.; COOK, G.J.; SVENSSON, W.E.; PETERS, A.M.; LEVICK, J.R.; MORTIMER, P.S.

2005-01-01

Background: In arm lymphedema secondary to axillary surgery and radiotherapy (breast cancer-related lymphedema), the swelling is largely epifascial and lymph flow per unit epifascial volume is impaired. The subfascial muscle compartment is not measurably swollen despite the iatrogenic damage to its axillary drainage pathway, but this could be due to its low compliance. Our aim was to test the hypothesis that subfascial lymph drainage too is impaired. Methods and Results: Quantitative lymphoscintigraphy was used to measure the removal rate constant (local lymph flow per unit distribution volume) for technetium-99m-human immunoglobulin G injected intramuscularly in the forearms of nine women with unilateral lymphedema. The removal rate constant was on average 31% lower in the ipsilateral swollen forearm than in the contralateral forearm (swollen arm: −0.096 ± 0.041% min−1, contralateralarm: −0.138 ± 0.037% min−1; mean ± SD, p = 0.037). The decrease in subfascial rate constant correlated strongly with increase in arm volume (r 0.88, p = 0.002), even though the swelling is mainly epifascial. There was no convincing evidence of dermal backflow. Conclusions: Lymph flow in the subfascial muscle compartment is decreased in breast cancer-related lymphedema. The correlation between impairment of subfascial drainage and epifascial arm swelling could be because both depend on the severity of axillary damage, or because loss of function in subfascial lymphatics impairs drainage from the epifascial to the subfascial system. PMID:15624420

Renal function and urine drainage after conservative or operative treatment of primary (obstructive) megaureter in infants and children.

PubMed

Tröbs, R-B; Heinecke, K; Elouahidi, T; Nounla, J; Kluge, R

2006-01-01

We examined renal function and urinary drainage of children with primary megaureter (PMU) in dependence on conservative or operative treatment. The retrospective analysis covering the years 1994 to 2000 comprised children at an age of 0-7 years with 35 PMU. Sonography, dynamic MAG3 renography as well as endogenic creatinine clearance (GFR) were used to assess drainage and the renal function. Temporary urinary diversion was established in fourteen patients of both groups. In 14 children with 16 PMU a ureteroneocystostomy (UNC) was performed. The average observation period was 30 months (11-108). The children of the UNC group differed from the non-neoimplanted group in the age at diagnosis (10.5 vs. < 1 months), higher degrees of hydronephrosis on average, a more distinct dilatation of the ureter as well as renographically significant obstruction. Children of the non-UNC group, including four children with a type B drainage curve (O'Reilly), had an unimpaired differential renal function or improved during the observation period (initially 51% vs. 50.5% at the end). In neoimplantation group the differential function improved from 32.5% to 38.5% (p < 0.05) and obstruction resolved with one exception. Given a higher-grade PMU with a reduced function of the kidneys and a significant impaired drainage pattern and/or symptoms, neoimplantation without temporary diversion has proved to be an efficient renoprotective method. Furthermore, data clearly justify a conservative approach without urinary diversion in infants with large asymptomatic PMU.

Standard (head-down tilt) versus modified (without head-down tilt) postural drainage in infants and young children with cystic fibrosis.

PubMed

Freitas, Diana A; Chaves, Gabriela Ss; Santino, Thayla A; Ribeiro, Cibele Td; Dias, Fernando Al; Guerra, Ricardo O; Mendonça, Karla Mpp

2018-03-09

Postural drainage is used primarily in infants with cystic fibrosis from diagnosis up to the moment when they are mature enough to actively participate in self-administered treatments. However, there is a risk of gastroesophageal reflux associated with this technique.This is an update of a review published in 2015. To compare the effects of standard postural drainage (15º to 45º head-down tilt) with modified postural drainage (15º to 30º head-up tilt) with regard to gastroesophageal reflux in infants and young children up to six years old with cystic fibrosis in terms of safety and efficacy. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Cystic Fibrosis Trials Register. We also searched the reference lists of relevant articles and reviews. Additional searches were conducted on ClinicalTrials.gov and on the WHO International Clinical Trials Registry Platform for any planned, ongoing and unpublished studies.The date of the most recent literature searches: 19 June 2017. We included randomised controlled studies that compared two postural drainage regimens (standard and modified postural drainage) with regard to gastroesophageal reflux in infants and young children (up to and including six years old) with cystic fibrosis. We used standard methodological procedures expected by Cochrane. Two review authors independently identified studies for inclusion, extracted outcome data and assessed risk of bias. We resolved disagreements by consensus or by involving a third review author. We contacted study authors to obtain missing or additional information. The quality of the evidence was assessed using GRADE. Two studies, involving a total of 40 participants, were eligible for inclusion in the review. We included no new studies in the 2018 update. The included studies were different in terms of the age of participants, the angle of tilt, the reported outcomes, the number of sessions and the study duration. The following outcomes were measured: appearance or exacerbation of gastroesophageal reflux episodes; percentage of peripheral oxygen saturation; number of exacerbations of upper respiratory tract symptoms; number of days on antibiotics for acute exacerbations; chest X-ray scores; and pulmonary function tests. One study reported that postural drainage with a 20° head-down position did not appear to exacerbate gastroesophageal reflux. However, the majority of the reflux episodes in this study reached the upper oesophagus (moderate-quality evidence). The second included study reported that modified postural drainage (30° head-up tilt) was associated with fewer number of gastroesophageal reflux episodes and fewer respiratory complications than standard postural drainage (30° head-down tilt) (moderate-quality evidence). The included studies had an overall low risk of bias. One included study was funded by the Sydney Children's Hospital Foundation and the other by the Royal Children's Hospital Research Foundation and Physiotherapy Research Foundation of Australia. Data were not able to be pooled by meta-analysis due to differences in the statistical presentation of the data. The limited evidence regarding the comparison between the two regimens of postural drainage is still weak due to the small number of included studies, the small number of participants assessed, the inability to perform any meta-analyses and some methodological issues with the studies. However, it may be inferred that the use of a postural regimen with a 30° head-up tilt is associated with a lower number of gastroesophageal reflux episodes and fewer respiratory complications in the long term. The 20° head-down postural drainage position was not found to be significantly different from the 20° head-up tilt modified position. Nevertheless, the fact that the majority of reflux episodes reached the upper oesophagus should make physiotherapists carefully consider their treatment strategy. We do not envisage that there will be any new trials undertaken that will affect the conclusions of this review; therefore, we do not plan to update this review.

Functional discrepancy between two liver lobes after hemilobe biliary drainage in patients with jaundice and bile duct cancer: an appraisal using (99m)Tc-GSA SPECT/CT fusion imaging.

PubMed

Sumiyoshi, Tatsuaki; Shima, Yasuo; Okabayashi, Takehiro; Noda, Yoshihiro; Hata, Yasuhiro; Murata, Yoriko; Kozuki, Akihito; Tokumaru, Teppei; Nakamura, Toshio; Uka, Kiminori

2014-11-01

To determine the functional discrepancy between the two liver lobes using technetium 99m ((99m)Tc) diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ( GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin ) single photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging following preoperative biliary drainage and portal vein embolization ( PVE portal vein embolization ) in patients with jaundice who have bile duct cancer ( BDC bile duct cancer ). This retrospective study was approved by the institutional review board, with waiver of informed consent. Preoperative (99m)Tc- GSA diethylenetriamine-pentaacetic acid-galactosyl human serum albumin SPECT/CT fusion images from 32 patients with extrahepatic BDC bile duct cancer were retrospectively reviewed. Patients were classified into four groups according to the extent of biliary drainage and presence of a preoperative right PVE portal vein embolization : right lobe drainage group (right drainage), bilateral lobe drainage group (bilateral drainage), left lobe drainage group (left drainage), and left lobe drainage with right PVE portal vein embolization group (left drainage with right PVE portal vein embolization ). Percentage volume and percentage function were measured in each lobe using fusion imaging. The ratio between percentage function and percentage volume (the function-to-volume ratio) was calculated for each lobe, and the results were compared among the four groups. Statistical analysis was performed with Wilcoxon signed-rank tests and Mann-Whitney U tests. The median values for the function-to-volume ratio in the right drainage, bilateral drainage, left drainage, and left drainage with right PVE portal vein embolization group were 1.12, 1.05, 1.02, and 0.81 in the right lobe; and 0.51, 0.88, 0.96, and 1.17 in the left lobe. Significant differences in the function-to-volume ratio were observed among the four groups (right drainage vs bilateral drainage vs left drainage vs left drainage with right PVE portal vein embolization ; with P < .002, P = .023, and P < .002 for the right lobe and P < .001, P = .023, and P < .002 for the left lobe). Hepatic lobar function significantly differs between the two lobes, depending on the extent of biliary drainage and the presence of portal vein embolization.

Determining the area of influence of depression cone in the vicinity of lignite mine by means of triangle method and LANDSAT TM/ETM+ satellite images.

PubMed

Zawadzki, Jarosław; Przeździecki, Karol; Miatkowski, Zygmunt

2016-01-15

Problems with lowering of water table are common all over the world. Intensive pumping of water from aquifers for consumption, irrigation, industrial or mining purposes often causes groundwater depletion and results in the formation of cone of depression. This can severely decrease water pressure, even over vast areas, and can create severe problems such as degradation of agriculture or natural environment sometimes depriving people and animals of water supply. In this paper, the authors present a method for determining the area of influence of a groundwater depression cone resulting from prolonged drainage, by means of satellite images in optical, near infrared and thermal infrared bands from TM sensor (Thematic Mapper) and ETM+ sensor (Enhanced Thematic Mapper +) placed on Landsat 5 and Landsat 7 satellites. The research area was Szczercowska Valley (Pol. Kotlina Szczercowska), Central Poland, located within a range of influence of a groundwater drainage system of the lignite coal mine in Belchatow. It is the biggest lignite coal mine in Poland and one of the largest in Europe exerting an enormous impact on the environment. The main method of satellite data analysis for determining soil moisture, was the so-called triangle method. This method, based on TVDI (Temperature Vegetation Dryness Index) was supported by additional spatial analysis including ordinary kriging used in order to combine fragmentary information obtained from areas covered by meadows. The results obtained are encouraging and confirm the usefulness of the triangle method not only for soil moisture determination but also for assessment of the temporal and spatial changes in the area influenced by the groundwater depression cone. The range of impact of the groundwater depression cone determined by means of above-described remote sensing analysis shows good agreement with that determined by ground measurements. The developed satellite method is much faster and cheaper than in-situ measurements, and allows for systematic monitoring of the vast area in the vicinity of Belchatow lignite mine. Besides, this method could be useful as a helper in in-situ measurement allowing a significant reduction of the number of in-situ measurements by performing them only within problematic areas. Hence, the triangle method can be used as an effective supplement to field measurements. Although the research area is located in Poland, in the vicinity of lignite mine, the method of observation of depression cones provided in this study is universal and effective, and therefore could also be useful to an international audience. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-quality observation of surface imperviousness for urban runoff modelling using UAV imagery

NASA Astrophysics Data System (ADS)

Tokarczyk, P.; Leitao, J. P.; Rieckermann, J.; Schindler, K.; Blumensaat, F.

2015-10-01

Modelling rainfall-runoff in urban areas is increasingly applied to support flood risk assessment, particularly against the background of a changing climate and an increasing urbanization. These models typically rely on high-quality data for rainfall and surface characteristics of the catchment area as model input. While recent research in urban drainage has been focusing on providing spatially detailed rainfall data, the technological advances in remote sensing that ease the acquisition of detailed land-use information are less prominently discussed within the community. The relevance of such methods increases as in many parts of the globe, accurate land-use information is generally lacking, because detailed image data are often unavailable. Modern unmanned aerial vehicles (UAVs) allow one to acquire high-resolution images on a local level at comparably lower cost, performing on-demand repetitive measurements and obtaining a degree of detail tailored for the purpose of the study. In this study, we investigate for the first time the possibility of deriving high-resolution imperviousness maps for urban areas from UAV imagery and of using this information as input for urban drainage models. To do so, an automatic processing pipeline with a modern classification method is proposed and evaluated in a state-of-the-art urban drainage modelling exercise. In a real-life case study (Lucerne, Switzerland), we compare imperviousness maps generated using a fixed-wing consumer micro-UAV and standard large-format aerial images acquired by the Swiss national mapping agency (swisstopo). After assessing their overall accuracy, we perform an end-to-end comparison, in which they are used as an input for an urban drainage model. Then, we evaluate the influence which different image data sources and their processing methods have on hydrological and hydraulic model performance. We analyse the surface runoff of the 307 individual subcatchments regarding relevant attributes, such as peak runoff and runoff volume. Finally, we evaluate the model's channel flow prediction performance through a cross-comparison with reference flow measured at the catchment outlet. We show that imperviousness maps generated from UAV images processed with modern classification methods achieve an accuracy comparable to standard, off-the-shelf aerial imagery. In the examined case study, we find that the different imperviousness maps only have a limited influence on predicted surface runoff and pipe flows, when traditional workflows are used. We expect that they will have a substantial influence when more detailed modelling approaches are employed to characterize land use and to predict surface runoff. We conclude that UAV imagery represents a valuable alternative data source for urban drainage model applications due to the possibility of flexibly acquiring up-to-date aerial images at a quality compared with off-the-shelf image products and a competitive price at the same time. We believe that in the future, urban drainage models representing a higher degree of spatial detail will fully benefit from the strengths of UAV imagery.

Modes of supraglacial lake drainage and dynamic ice sheet response

NASA Astrophysics Data System (ADS)

Das, S. B.; Behn, M. D.; Joughin, I. R.

2011-12-01

We investigate modes of supraglacial lake drainage using geophysical, ground, and remote sensing observations over the western margin of the Greenland ice sheet. Lakes exhibit a characteristic life cycle defined by a pre-drainage, drainage, and post-drainage phase. In the pre-drainage phase winter snow fills pre-existing cracks and stream channels, efficiently blocking past drainage conduits. As temperatures increase in the spring, surface melting commences, initially saturating the snow pack and subsequently forming a surface network of streams that fills the lake basins. Basins continue to fill until lake drainage commences, which for individual lakes occurs at different times depending on the previous winter snow accumulation and summer temperatures. Three styles of drainage behavior have been observed: (1) no drainage, (2) slow drainage over the side into an adjacent pre-existing crack, and (3) rapid drainage through a new crack formed beneath the lake basin. Moreover, from year-to-year individual lakes exhibit different drainage behaviors. Lakes that drain slowly often utilize the same outflow channel for multiple years, creating dramatic canyons in the ice. Ultimately, these surface channels are advected out of the lake basin and a new channel forms. In the post-drainage phase, melt water continues to access the bed typically through a small conduit (e.g. moulin) formed near a local topographic minimum along the main drainage crack, draining the lake catchment throughout the remainder of the melt season. This melt water input to the bed leads to continued basal lubrication and enhanced ice flow compared to background velocities. Lakes that do not completely drain freeze over to form a surface ice layer that persists into the following year. Our results show that supraglacial lakes show a spectrum of drainage behaviors and that these styles of drainage lead to varying rates and timing of surface meltwater delivery to the bed resulting in different dynamic ice responses.

Development of a rational method for predicting corrosion rates of metals in soils and water : final report, October 31, 2009.

DOT National Transportation Integrated Search

2009-10-31

Methods used by the Florida Department of Transportation for predicting corrosion rates of metallic piling, anchors, and metallic drainage pipe used in highway construction were examined and updates were proposed as needed.

Global 30m Height Above the Nearest Drainage

NASA Astrophysics Data System (ADS)

Donchyts, Gennadii; Winsemius, Hessel; Schellekens, Jaap; Erickson, Tyler; Gao, Hongkai; Savenije, Hubert; van de Giesen, Nick

2016-04-01

Variability of the Earth surface is the primary characteristics affecting the flow of surface and subsurface water. Digital elevation models, usually represented as height maps above some well-defined vertical datum, are used a lot to compute hydrologic parameters such as local flow directions, drainage area, drainage network pattern, and many others. Usually, it requires a significant effort to derive these parameters at a global scale. One hydrological characteristic introduced in the last decade is Height Above the Nearest Drainage (HAND): a digital elevation model normalized using nearest drainage. This parameter has been shown to be useful for many hydrological and more general purpose applications, such as landscape hazard mapping, landform classification, remote sensing and rainfall-runoff modeling. One of the essential characteristics of HAND is its ability to capture heterogeneities in local environments, difficult to measure or model otherwise. While many applications of HAND were published in the academic literature, no studies analyze its variability on a global scale, especially, using higher resolution DEMs, such as the new, one arc-second (approximately 30m) resolution version of SRTM. In this work, we will present the first global version of HAND computed using a mosaic of two DEMS: 30m SRTM and Viewfinderpanorama DEM (90m). The lower resolution DEM was used to cover latitudes above 60 degrees north and below 56 degrees south where SRTM is not available. We compute HAND using the unmodified version of the input DEMs to ensure consistency with the original elevation model. We have parallelized processing by generating a homogenized, equal-area version of HydroBASINS catchments. The resulting catchment boundaries were used to perform processing using 30m resolution DEM. To compute HAND, a new version of D8 local drainage directions as well as flow accumulation were calculated. The latter was used to estimate river head by incorporating fixed and variable thresholding methods. The resulting HAND dataset was analyzed regarding its spatial variability and to assess the global distribution of the main landform types: valley, ecotone, slope, and plateau. The method used to compute HAND was implemented using PCRaster software, running on Google Compute Engine platform running under Ubuntu Linux. The Google Earth Engine was used to perform mosaicing and clipping of the original DEMs as well as to provide access to the final product. The effort took about three months of computing time on eight core CPU virtual machine.

Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis.

PubMed

Hong, Kun-Hao; Pan, Jian-Ke; Yang, Wei-Yi; Luo, Ming-Hui; Xu, Shu-Chai; Liu, Jun

2016-08-01

Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage. PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3-5, length of hospital stay and wound infections after TKA surgery. The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3-5, length of hospital stay and wound infections. Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

Fishhook removal

MedlinePlus

... such as redness, swelling, pain, or drainage. Wire cutting method: First, wash your hands with soap and ... is casting. Keep electrician's pliers with a wire-cutting blade and disinfecting solution in your tackle box. ...

Surgical treatment of chronic pancreatitis and its complications. Comparative analysis of results in 91 patients.

PubMed

Marinov, V; Draganov, K; Gaydarski, R; Katev, N N

2013-01-01

There is a large variety of proposed conservative, invasive, endoscopic and surgical methods for treatment of chronic pancreatitis and its complications. This study presents a comparative analysis of the results from each group of patients subjected to drainage, resection, denervation and other operative techniques for a total of 91 patients with chronic pancreatitis and its complications. Drainage and resection operative techniques yield comparable results in terms of postoperative pain control 93.1% and 100%, perioperative mortality--3.17% and 5.8%, perioperative morbidity--7.9% and 11.7%, respectively. There is a significant increase in the instances of diabetes in the resection group. Right-side semilunar ganglionectomy is a good method for pain control as an accompanying procedure in the course of another main operative technique.

Variability of Short-term Precipitation and Runoff in Small Czech Drainage Basins

NASA Astrophysics Data System (ADS)

Kavka, Petr; Strouhal, Luděk; Landa, Martin; Neuman, Martin; Kožant, Petr; Muller, Miloslav

2016-04-01

The aim of this contribution is to introduce the recently started three year's project named "Variability of Short-term Precipitation and Runoff in Small Czech Drainage Basins and its Influence on Water Resources Management". Its main goal is to elaborate a methodology and online utility for deriving short-term design precipitation series, which could be utilized by a broad community of scientists, state administration as well as design planners. The outcomes of the project will especially be helpful in modelling hydrological or soil erosion problems when designing common measures for promoting water retention or landscape drainage systems in or out of the scope of Landscape consolidation projects. The precipitation scenarios will be derived from 10 years of observed data from point gauging stations and radar data. The analysis is focused on events' return period, rainfall total amount, internal intensity distribution and spatial distribution over the area of Czech Republic. The methodology will account for the choice of the simulation model. Several representatives of practically oriented models will be tested for the output sensitivity to selected precipitation scenario comparing to variability connected with other inputs uncertainty. The variability of the outputs will also be assessed in the context of economic impacts in design of landscape water structures or mitigation measures. The research was supported by the grant QJ1520265 of the Czech Ministry of Agriculture, using data provided by the Czech Hydrometeorological Institute.

[Observation of the use of percutaneous tracheostomy tube for closed drainage of pneumothorax in intensive care unit].

PubMed

Kang, Hongshan; Bai, Yan; Ma, Hongfang; Du, Zhiyong; Ma, Zhen; Wang, Huiqing; Liu, Yajing; Liu, Shuhong; Cui, Zhaobo

2014-12-01

To explore the effect of the transcutaneous tracheostomy tube in patients with pneumothorax and its clinical value. A prospective randomized controlled trial was conducted. Thirty-two patients with pneumothorax admitted to Department of Critical Care Medicine of Harrison International Peace Hospital of Hebei Medical University from June 2010 to June 2014 were enrolled. The patients were divided into control group and observation group, with 16 cases in each group. Beside the treatment for primary disease, the patients in control group received thoracic close drainage with traditional silica gel tube as performed by thoracic surgeons, and those in observation group received thoracic close drainage with transcutaneous tracheostomy tube by intensive care doctors. The curative effect and complications of the two groups were observed. Compared with control group, the time from diagnosis to operation (minutes:8.00 ± 1.36 vs. 23.06 ± 3.83, t=14.790, P=0.000) and the operation time were significantly shortened (days:5.37 ± 1.02 vs. 7.31 ± 1.70, t=7.286, P=0.000), the frequency of drainage tube replacement (times: 0.18 ± 0.40 vs. 3.87 ± 1.14, t=12.128, P=0.000) and the times of repeated chest radiography (times:1.12 ± 0.34 vs. 2.93 ± 0.77, t=8.589, P=0.000) in observation group were significantly reduced, the length of hospital day was significantly shortened (days:8.30 ± 1.37 vs. 24.56 ± 5.62, t=17.289, P=0.000), the rates of dislocation of drainage tube (0 vs. 3 cases), obstruction of the tube (0 vs. 5 cases), and subcutaneous emphysema (3 vs. 16 cases) were reduced obviously, but there was no difference in incidence of incision infection (1 vs. 3 cases) and infection of thoracic cavity (0 vs. 2 cases). The usage of transcutaneous tracheostomy tube in patients with pneumothorax is safe and simple. Doctors in ICU can independently do this procedure, and its effect is positive.

CUA Annual Meeting Abstracts addition.

PubMed

2012-08-01

: Foley catheters are assumed to drain the bladder to completion. We have previously shown that dependent loops along the drainage tubing create air-locks, which obstruct antegrade urine flow and result in un-drained residual bladder urine. We hypothesized that drainage characteristics of Foley catheters remain poorly understood by urologists and general surgeons. We conducted a nationwide survey of general surgery and urology training program faculty and residents, to assess perceptions of Foley catheter drainage. We designed a novel catheter drainage tube/bag that eliminates air-locks. : An anonymous illustrated questionnaire assessing Foley catheter use patterns and perception was sent to general surgery and urology residency programs (N=108) nationwide. A modified catheter drainage tube/bag unit was designed and tested. An ex vivo catheterized bladder model was designed to measure and compare urine drainage rates with the standard drainage system, versus with our novel design. : A total of 307 responses were collected from residents (55%) and faculty (45%); responses were similar among both groups (p<0.05). The majority reported that at their centers Foley catheter drainage tubes are generally positioned with a dependent loop (94.1%), and, that positioning with a dependent loop, versus without (78.1%) promoted optimal drainage. Antegrade drainage does not occur with a traditional drainage system when a >5.5 inch dependent loop in place. With our proposed design, which eliminates dependent loops, the bladder model emptied to completion consistently. : Traditional Foley catheter drainage systems, as commonly used, evacuate the bladder sub- optimally. More reliable and complete bladder drainage may decrease the incidence of catheter related UTI. The novel modified Foley catheter drainage tube/bag design presented here eliminates dependent loops, to optimize antegrade drainage.

Lemierre's syndrome (necrobacillosis)

PubMed Central

Golpe, R.; Marin, B.; Alonso, M.

1999-01-01

Lemierre's syndrome or postanginal septicaemia (necrobacillosis) is caused by an acute oropharyngeal infection with secondary septic thrombophlebitis of the internal jugular vein and frequent metastatic infections. Fusobacterium necrophorum is the most common pathogen isolated from the patients. The interval between the oropharyngeal infection and the onset of the septicaemia is usually short. The most common sites of septic embolisms are the lungs and joints, and other locations can be affected. A high degree of clinical suspicion is needed to diagnose the syndrome. Computed tomography of the neck with contrast is the most useful study to detect internal jugular vein thrombosis. Treatment includes intravenous antibiotic therapy and drainage of septic foci. The role of anticoagulation is controversial. Ligation or excision of the internal jugular vein may be needed in some cases.


Keywords: Lemierre's syndrome; Fusobacterium necrophorum; necrobacillosis; septicaemia; oropharynx PMID:10448489

Translating evidence-based protocol of wound drain management for total joint arthroplasty into practice: A quasi-experimental study.

PubMed

Tsang, Lap Fung; Cheng, Hang Cheong; Ho, Hon Shuen; Hsu, Yung Chak; Chow, Chiu Man; Law, Heung Wah; Fong, Lup Chau; Leung, Lok Ming; Kong, Ivy Ching Yan; Chan, Chi Wai; Sham, Alice So Yuen

2016-05-01

Although various drains have long been used in total joint replacement, evidence suggests inconsistent practice exists in the use of drainage systems including intermittently applying suction or free of drainage suction, and variations in the optimal timing for wound drain removal. A comprehensive systematic review of available evidence up to 2013 was conducted in a previous study and a protocol was adapted for clinical application according to the summary of the retrieved information (Tsang, 2015). To determine if the protocol could reduce blood loss and blood transfusion after operation and to develop a record form so as to enhance communication of drainage record amongst surgeons and nurses. A quasi-experimental time-series design was undertaken. In the conventional group, surgeons ordered free drainage if the drain output was more than 300 ml. The time of removal of the drain was based on their professional judgement. In the protocol group the method of drainage was dependant of the drainage output as was the timing of the removal of the drain. A standardized record form was developed to guide operating room and orthopaedic ward nurses to manage the drainage system. The drain was removed significantly earlier in the protocol group. Blood loss rate at the first hour of post-operation was extremely low in the protocol group due to clamping effect. Blood loss in volume during the first three hours in the protocol group was significantly lower than that in the conventional group. Only in 11.1% and 4% of cases was it necessary to clamp at the three and four hour post-operative hours. No clamping was required at the two and eight hour postoperative period. There was no significant difference in blood loss during the removal of the drain and during blood transfusion, which was required for patients upon removal of the drain in the two groups. This is the first clinical study to develop an evidence-based protocol to manage wound drain effectively in Hong Kong. Total blood loss and blood transfusions were not significantly different between the conventional and protocol groups. A standard documentation document is beneficial to enhance communication between doctors and nurses as well as to monitor and observe drainage effectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Toward more accurate basal boundary conditions: a new 2-D model of distributed and channelised subglacial drainage

NASA Astrophysics Data System (ADS)

Werder, M. A.; Hewitt, I. J.; Schoof, C.; Flowers, G. E.

2012-04-01

Basal boundary conditions are one of the least constrained components of today's ice sheet models. To get at these one needs to know the distributed basal water pressure. We present a new glacier drainage system model to contribute to this missing piece of the puzzle. This two dimensional mathematical/numerical model combines distributed and channelised drainage at the ice-bed interface coupled to a water storage component. Notably the model determines the location of the channels as part of the solution. This is achieved by allowing channels (modelled as R-channels) to form on any of the edges of the unstructured triangular grid used to discretise the model. The distributed system is represented by a water sheet which is a continuum description of a linked-cavity system and exchanges water with the channels along their length. Water storage is parameterised as a function of the subglacial water pressure, which can be interpreted as storage in an englacial aquifer or due to elastic processes. The parabolic equation that determines the water pressure is solved using finite elements, the time evolution of the water sheet thickness and channel diameter are governed by local differential equations that are integrated using explicit methods. To explore the model's properties, we apply it to synthetic ice sheet catchments with areas up to 3000km2. We present steady state drainage system configurations and evaluate their channel-network properties (fractal dimensions, channel spacing). We find that an arborescent channel network forms whose density depends on the water sheet conductivity relative to water input. As a further experiment, we force the model with a seasonally and diurnally varying melt water input to investigate how the modelled drainage system evolves on these time scales: a channelised system grows up glacier as meltwater is delivered to the bed in spring and collapses in autumn. Water pressure is highest just before the formation of channels and then drops. Conversely, the diurnal variations in discharge affect the drainage system morphology only slightly. Instead they lead to large water pressure variations which lag meltwater input and coincide with changes in the volume of stored water. By incorporating an evolving R-channel network within a continuum model of distributed water drainage and storage, this 2-D model succeeds in qualitatively reproducing many of the observed and postulated features of the glacier drainage system.

Exploring Agricultural Drainage's Influence on Wetland and ...

EPA Pesticide Factsheets

Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie

[Clinical application of self-made drainage tube with balloon for iatrogenic colonic perforation].

PubMed

Liu, Bing-rong; Li, Hui; Zhao, Li-xia; Song, Ji-tao; Wang, Yan-jun; Chen, Jing; Liu, Wei

2012-07-01

To investigate the clinical efficacy of colonic bypass drainage by self-made drainage tube with balloon for iatrogenic colonic perforation. A retrospective analysis of 8 patients with iatrogenic colonic perforations from January 2009 to March 2011 was performed. Self-made drainage tubes with balloon were placed in the bowel lumen endoscopically after perforations were closed with endoclips or endoloops under endoscope. The inflatable balloon at the front-end of the tube was fixed at the mouth side of colonic perforation to achieve continuous drainage of stool and intestinal juice. Endoscopic bypass continuous drainage by using self-made drainage tube with balloon was successfully carried out in all the 8 patients. All the perforations healed and no surgical intervention required. Bypass drainage continued for 3-10 days(mean 7.6 days). One patient received colonoscopy 3 days after the procedure, and displacement of the drainage tube was noticed requiring endoscopic adjustment. All the drainage tubes were removed uneventfully, and no ulceration or perforation occurred at balloon fixed site after removal. After follow up ranging from 12 to 36 months, no chronic fistula, adhesive obstruction, or abdominal infection occurred. Colonic bypass drainage by self-made drainage tube with balloon for iatrogenic colonic perforation is simple, feasible, safe and reliable.

Traditional Foley drainage systems--do they drain the bladder?

PubMed

Garcia, Maurice M; Gulati, Shelly; Liepmann, Dorian; Stackhouse, G Bennett; Greene, Kirsten; Stoller, Marshall L

2007-01-01

Foley catheters are assumed to drain the bladder to completion. Drainage characteristics of Foley catheter systems are poorly understood. To investigate unrecognized retained urine with Foley catheter drainage systems, bladder volumes of hospitalized patients were measured with bladder scan ultrasound volumetrics. Additionally, an in vitro bench top mock bladder and urinary catheter system was developed to understand the etiology of such residual volumes. A novel drainage tube design that optimizes indwelling catheter drainage was also designed. Bedside bladder ultrasound volumetric studies were performed on patients hospitalized in ward and intensive care unit. If residual urine was identified the drainage tubing was manipulated to facilitate drainage. An ex vivo bladder-urinary catheter model was designed to measure flow rates and pressures within the drainage tubing of a traditional and a novel drainage tube system. A total of 75 patients in the intensive care unit underwent bladder ultrasound volumetrics. Mean residual volume was 96 ml (range 4 to 290). In 75 patients on the hospital ward mean residual volume was 136 ml (range 22 to 647). In the experimental model we found that for every 1 cm in curl height, obstruction pressure increased by 1 cm H2O within the artificial bladder. In contrast, the novel spiral-shaped drainage tube demonstrated rapid (0.5 cc per second), continuous and complete (100%) reservoir drainage in all trials. Traditional Foley catheter drainage systems evacuate the bladder suboptimally. Outflow obstruction is caused by air-locks that develop within curled redundant drainage tubing segments. The novel drainage tubing design eliminates gravity dependent curls and associated air-locks, optimizes flow, and minimizes residual bladder urine.

Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST): a protocol for a multicentre randomised controlled trial.

PubMed

Kato, Shin; Kuwatani, Masaki; Sugiura, Ryo; Sano, Itsuki; Kawakubo, Kazumichi; Ono, Kota; Sakamoto, Naoya

2017-08-11

The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naïve major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016-0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. The University Hospital Medical Information Network ID: UMIN000025727 Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Bundle of measures for external cerebral ventricular drainage-associated ventriculitis.

PubMed

Chatzi, Maria; Karvouniaris, Marios; Makris, Demosthenes; Tsimitrea, Eleni; Gatos, Charalampos; Tasiou, Anastasia; Mantzarlis, Kostas; Fountas, Kostas N; Zakynthinos, Epaminondas

2014-01-01

To assess the prevalence and outcome of external cerebral ventricular drainage-associated ventriculitis in neurocritical patients before and after the implementation of a bundle of external cerebral ventricular drainage-associated ventriculitis control measures. Clinical prospective case series. University Hospital of Larissa, Greece. Consecutive patients were recruited from the ICU of the hospital. Patient inclusion criteria included presence of external ventricular drainage and ICU stay more than 48 hours. The bundle of external cerebral ventricular drainage-associated ventriculitis control measures included 1) reeducation of ICU personnel on issues of infection control related to external cerebral ventricular drainage, 2) meticulous intraventricular catheter handling, 3) cerebrospinal fluid sampling only when clinically necessary, and 4) routine replacement of the drainage catheter on the seventh drainage day if the catheter was still necessary. The bundle was applied after an initial period (preintervention) where standard policy for external cerebral ventricular drainage-associated ventriculitis was established. External cerebral ventricular drainage-associated ventriculitis prevalence, external cerebral ventricular drainage-associated ventriculitis events per 1,000 drainage days (drain-associated infection rate), length of ICU stay, Glasgow Outcome Scale at 6 months, and risk factors for external cerebral ventricular drainage-associated ventriculitis. Eighty-two patients entered the study in the preintervention period and 57 patients during the intervention period. During the preintervention and intervention period, external cerebral ventricular drainage-associated ventriculitis prevalence was 28% and 10.5% (p = 0.02) and drain-associated infection rate was 18 and 7.1, respectively (p = 0.0001); mean (95% CI) length of ICU stay in patients who presented external cerebral ventricular drainage-associated ventriculitis was 44.4 days (36.4-52.4 d), whereas mean (95% CI) length of ICU stay in patients who did not was 20 days (16.9-23.2 d) (p < 0.001). Furthermore, the length of ICU stay was associated with length of drainage (p = 0.0001). Therefore, the presence of external cerebral ventricular drainage-associated ventriculitis and the length of drainage were the only variables associated with a prolonged ICU stay. Unfavorable outcome in Glasgow Outcome Scale at 6 months was not associated with the presence of external cerebral ventricular drainage-associated ventriculitis (p = 0.5). No significant differences were found when Glasgow Outcome Scale was analyzed according to the two study periods. The implementation of a bundle of measures for external cerebral ventricular drainage-associated ventriculitis control was associated with significantly decreased postintervention prevalence of the infection.

Easy clip to treat anal fistula tracts: a word of caution.

PubMed

Gautier, M; Godeberge, P; Ganansia, R; Bozio, G; Godart, B; Bigard, M A; Barthet, M; Siproudhis, L

2015-05-01

Closing the internal opening by a clip ovesco has been recently proposed for healing the fistula tract, but, to date, data on benefit are poorly analyzed. The aim was to report a preliminary multicenter experience. Retrospective study was undertaken in six different French centers: surgical procedure, immediate complications, and follow-up have been collected. Nineteen clips were inserted in 17 patients (M/F, 4/13; median age, 42 years [29-54]) who had an anal fistula: 12 (71%) high fistulas (including 4 rectovaginal fistulas), 5 (29%) lower fistulas (with 3 rectovaginal fistulas), and 6 (35%) Crohn's fistulas. Out of 17 patients, 15 had a seton drainage beforehand. The procedure was easy in 8 (47%) patients and the median operative time was 27.5 min (20-36.5). Postoperative period was painful for 11 (65%) patients. A clip migration was noted in 11 patients (65%) after a median follow-up of 10 days (5.5-49.8). Eleven patients (65%) who failed had reoperation including 10 new drainages within the first month (0.5-5). After a mean follow-up of 4 months (2-7),, closing the tract was observed in 2 patients (12%) following the first insertion of the clip and in another one after a second insertion. Treatment of anal fistula by placing a clip on the internal opening is disappointing and deleterious for some patients. A better assessment before dissemination is recommended.

The Borderlands - A region of physical and cultural diversity: Chapter 2 in United States-Mexican Borderlands: Facing tomorrow's challenges through USGS science

USGS Publications Warehouse

Parcher, Jean W.; Papoulias, Diana M.; Woodward, Dennis G.; Durall, Roger A.

2013-01-01

The area surrounding the United States–Mexican border is very physically and culturally diverse and cannot be generalized by any single description. To assist in an accurate appraisal and understanding of this remarkable region, the Borderlands team has divided it into eight subareas based on the watershed subareas of the U.S. Geological Survey Border Environmental Health Initiative (http://borderhealth.cr.usgs.gov) (fig. 2–1), the boundaries of which are defined primarily by surface-water drainage basins. The drainage basins directly adjacent to or crossing the international boundary were automatically included in the defined border region, as were those basins that contain unconsolidated aquifers that extend to or cross the international boundary. Also, “protected areas” adjacent to included basins were selectively added to the defined border region. Though some geographic features are entirely within the Borderlands, many features—deserts, mountain ranges, rivers, etc.— extend beyond the region boundaries but are still influential to Borderlands environments (fig. 2–2). In some cases, the authors of the following chapters have made fine adjustments to the Borderlands boundaries, and they have described those alterations where necessary. By describing and studying these subareas individually and comparing them to one another, we can emphasize the physical and cultural diversity that makes the Borderlands such an important geographic area.

[Metastasis of Hepatocellular Carcinoma to the Membrane of Chronic Subdural Hematomas:A Case Report].

PubMed

Oshita, Jumpei; Ohba, Shinji; Itou, Yoko; Yonezawa, Koki; Hosogai, Masahiro

2017-10-01

An 81-year-old man presented with gait disturbance. Two months previously, he suffered from hepatocellular carcinoma and transarterial chemoembolization was performed. A head computed tomography(CT)scan revealed bilateral chronic subdural hematomas. The patient's gait disturbance was improved after achievement of bilateral burr hole drainage. A head CT two months after treatment revealed no recurrence of the hematomas. However, head CT images obtained four months after treatment revealed an abnormal mass in the right parietal region attached to the internal surface of the skull. The mass was located in the same region from where the chronic subdural hematomas were previously removed via burr hole drainage, and was suspected to have originated from the dura mater. We performed craniotomy and total removal of the mass. The dura mater was intact, and macroscopically, the mass originated from the organized membrane of the chronic subdural hematoma. A pathological examination revealed metastasis of hepatocellular carcinoma to the membrane of the chronic subdural hematomas. Head magnetic resonance imaging(MRI)performed 39 days after craniotomy presented a new lesion in the left parietal region attached to the internal surface of the skull. The patient subsequently died 46 days post-operation. When examining chronic subdural hematomas in cancer patients, histological examination of the dura mater, hematoma, and membrane of the hematoma are important. The possibility of metastasis to the capsule of the hematoma should be considered.

Characterize the hydraulic behaviour of grate inlet in urban drainage to prevent the urban's flooding

NASA Astrophysics Data System (ADS)

Tellez Alvarez, Jackson David; Gomez, Manuel; Russo, Beniamino; Redondo, Jose M.

2016-04-01

One of the most important problems that have some cities is the urban floods because of poor drainage design. Therefore the systems the drainage do not have the capacity of capture the flow of discharge generated in a rain event and insert it into the drainage network. Even though the two problems that have caught the main attention are the evaluation of the volumes falling in the river basin because extreme rainfall events often lead to urban pluvial flooding being a hydrologic problem and the hydraulic design of the sewer network being a hydraulic problem to limiting capacity of the drainage system, there is an intermediate step between these two processes that is necessary to solve that is the hydraulic behavior of the grate inlet. We need to collect the runoff produced on the city surface and to introduce it in the sewer network. Normally foundry companies provide complete information about drainage grate structural capacity but provide nothing about their hydraulic capacity. This fact can be seen because at the moment does not exist any official regulation at national or international level in this field. It's obvious that, nowadays, there is a great gap in this field at the legislative level owing to the complexity of this field and the modernity of the urban hydrology as science [1]. In essence, we shows the relevance to know the inlet hydraulic interception capacity because surface drainage requires a satisfactory knowledge on storm frequency, gutter flow and above all inlet capacity. In addition, we development an important achievement is the invention and development of techniques for measurement of field velocities in hydraulics engineering applications. Hence knowledge the technological advances in digital cameras with high resolution and high speed found in the environmental, and the advances in image processing techniques, therefore now is a tremendous potential to obtain of behavior of the water surface flow [2]. A novel technique using particle image velocimetry to measure surface flow velocities has been developed and validated with the experiments assays with the grate inlets [3 - 4]. Indeed, the Methodology carried out can become a useful tools to understand the hydraulics behavior of the flow approaching the inlet where the traditional measuring equipment have serious problems and limitations [5 - 6]. References [1] Gómez, M., Macchione, F. and Russo, B. (2006). Inlet systems and risk criteria associated to street runoff application to urban drainage catchments. 27 Corso di aggiornamiento in techniche per la difesa dall'inquinamento. [2] Russo, B., Gómez, M., & Tellez, J. (2013). Methodology to Estimate the Hydraulic Efficiency of Nontested Continuous Transverse Grates. Journal of Irrigation and Drainage Engineering, 139(10), 864-871. doi:10.1061/(ASCE)IR.1943-4774.0000625 [3] DigiFlow. User Guide. (2012), (June). [4] Vila, T., Tellez, J., Sanchez, J.M., Sotillos, L., Diez, M., and Redondo, J.M. (2014). Diffusion in fractal wakes and convective thermoelectric flows. Geophysical Research Abstracts - EGU General Assembly 2014. [5] Tellez, J., Gómez, M., Russo, B. and Redondo, J.M. (2014). A simple technique to measuring surface flow velocity to analyze the behavior of fields velocities in hydraulics engineer applications. Geophysical Research Abstracts - EGU General Assembly 2015. [6] Tellez, J., Gómez, M. and Russo, B. (2015). Técnica para la obtención del campo de velocidad del flujo superficial en proximidad de rejas de alcantarillado. IV Jornadas de Ingeniería del Agua. La precipitación y los procesos erosivos.

Equations for estimating bankfull channel geometry and discharge for streams in Massachusetts

USGS Publications Warehouse

Bent, Gardner C.; Waite, Andrew M.

2013-01-01

Regression equations were developed for estimating bankfull geometry—width, mean depth, cross-sectional area—and discharge for streams in Massachusetts. The equations provide water-resource and conservation managers with methods for estimating bankfull characteristics at specific stream sites in Massachusetts. This information can be used for the adminstration of the Commonwealth of Massachusetts Rivers Protection Act of 1996, which establishes a protected riverfront area extending from the mean annual high-water line corresponding to the elevation of bankfull discharge along each side of a perennial stream. Additionally, information on bankfull channel geometry and discharge are important to Federal, State, and local government agencies and private organizations involved in stream assessment and restoration projects. Regression equations are based on data from stream surveys at 33 sites (32 streamgages and 1 crest-stage gage operated by the U.S. Geological Survey) in and near Massachusetts. Drainage areas of the 33 sites ranged from 0.60 to 329 square miles (mi2). At 27 of the 33 sites, field data were collected and analyses were done to determine bankfull channel geometry and discharge as part of the present study. For 6 of the 33 sites, data on bankfull channel geometry and discharge were compiled from other studies done by the U.S. Geological Survey, Natural Resources Conservation Service of the U.S. Department of Agriculture, and the Vermont Department of Environmental Conservation. Similar techniques were used for field data collection and analysis for bankfull channel geometry and discharge at all 33 sites. Recurrence intervals of the bankfull discharge, which represent the frequency with which a stream fills its channel, averaged 1.53 years (median value 1.34 years) at the 33 sites. Simple regression equations were developed for bankfull width, mean depth, cross-sectional area, and discharge using drainage area, which is the most significant explanatory variable in estimating these bankfull characteristics. The use of drainage area as an explanatory variable is also the most commonly published method for estimating these bankfull characteristics. Regional curves (graphic plots) of bankfull channel geometry and discharge by drainage area are presented. The regional curves are based on the simple regression equations and can be used to estimate bankfull characteristics from drainage area. Multiple regression analysis, which includes basin characteristics in addition to drainage area, also was used to develop equations. Variability in bankfull width, mean depth, cross-sectional area, and discharge was more fully explained by the multiple regression equations that include mean-basin slope and drainage area than was explained by equations based on drainage area alone. The Massachusetts regional curves and equations developed in this study are similar, in terms of values of slopes and intercepts, to those developed for other parts of the northeastern United States. Limitations associated with site selection and development of the equations resulted in some constraints for the application of equations and regional curves presented in this report. The curves and equations are applicable to stream sites that have (1) less than about 25 percent of their drainage basin area occupied by urban land use (commercial, industrial, transportation, and high-density residential), (2) little to no streamflow regulation, especially from flood-control structures, (3) drainage basin areas greater than 0.60 mi2 and less than 329 mi2, and (4) a mean basin slope greater than 2.2 percent and less than 23.9 percent. The equations may not be applicable where streams flow through extensive wetlands. The equations also may not apply in areas of Cape Cod and the Islands and the area of southeastern Massachusetts close to Cape Cod with extensive areas of coarse-grained glacial deposits where none of the study sites are located. Regardless of the setting, the regression equations are not intended for use as the sole method of estimating bankfull characteristics; however, they may supplement field identification of the bankfull channel when used in conjunction with field verified bankfull indicators, flood-frequency analysis, or other supporting evidence.

Visualization and quantification of capillary drainage in the pore space of laminated sandstone by a porous plate method using differential imaging X-ray microtomography

NASA Astrophysics Data System (ADS)

Lin, Qingyang; Bijeljic, Branko; Rieke, Holger; Blunt, Martin J.

2017-08-01

The experimental determination of capillary pressure drainage curves at the pore scale is of vital importance for the mapping of reservoir fluid distribution. To fully characterize capillary drainage in a complex pore space, we design a differential imaging-based porous plate (DIPP) method using X-ray microtomography. For an exemplar mm-scale laminated sandstone microcore with a porous plate, we quantify the displacement from resolvable macropores and subresolution micropores. Nitrogen (N2) was injected as the nonwetting phase at a constant pressure while the porous plate prevented its escape. The measured porosity and capillary pressure at the imaged saturations agree well with helium measurements and experiments on larger core samples, while providing a pore-scale explanation of the fluid distribution. We observed that the majority of the brine was displaced by N2 in macropores at low capillary pressures, followed by a further brine displacement in micropores when capillary pressure increases. Furthermore, we were able to discern that brine predominantly remained within the subresolution micropores, such as regions of fine lamination. The capillary pressure curve for pressures ranging from 0 to 1151 kPa is provided from the image analysis compares well with the conventional porous plate method for a cm-scale core but was conducted over a period of 10 days rather than up to few months with the conventional porous plate method. Overall, we demonstrate the capability of our method to provide quantitative information on two-phase saturation in heterogeneous core samples for a wide range of capillary pressures even at scales smaller than the micro-CT resolution.

Sulphates Removal from Acid Mine Drainage

NASA Astrophysics Data System (ADS)

Luptáková, Alena; Mačingová, Eva; Kotuličová, Ingrida; Rudzanová, Dominika

2016-10-01

Acid mine drainage (AMD) are a worldwide problem leading to ecological destruction in river basins and the contamination of water sources. AMD are characterized by low pH and high content of heavy metals and sulphates. In order to minimize negative impacts of AMD appropriate treatment techniques has to be chosen. Treatment processes are focused on neutralizing, stabilizing and removing pollutants. From this reason efficient and environmental friendly methods are needed to be developed in order to reduce heavy metals as well as sulphates. Various methods are used for remediation of acid mine drainage, but any of them have been applied under commercial-scale conditions. Their application depends on geochemical, technical, natural, financial, and other factors. The aim of the present work was to interpret the study of biological methods for sulphates removal from AMD out-flowing from the shaft Pech of the deposit Smolmk in Slovak Republic. In the experimental works AMD were used after removal of heavy metals by precipitation and sorption using the synthetic sorbent Slovakite. The base of the studied method for the sulphates elimination was the anaerobic bacterial sulphate reduction using sulphate-reducing bacteria (SRB) genera Desulfovibrio. SRB represent a group of bacteria that uses sulphates as a terminal electron acceptor for their metabolism. These bacteria realize the conversion of sulphate to hydrogen sulphide under anaerobic conditions. For the purposes of experiments a few variants of the selective medium DSM-63 culture media were used in term of the sulphates and sodium lactate contents in the selective medium as well as sulphates in the studied AMD.

Maximum known stages and discharges of New York streams and their annual exceedance probabilities through September 2011

USGS Publications Warehouse

Wall, Gary R.; Murray, Patricia M.; Lumia, Richard; Suro, Thomas P.

2014-01-01

Maximum known stages and discharges at 1,400 sites on 796 streams within New York are tabulated. Stage data are reported in feet. Discharges are reported as cubic feet per second and in cubic feet per second per square mile. Drainage areas range from 0.03 to 298,800 square miles; excluding the three sites with larger drainage areas on the St. Lawrence and Niagara Rivers, which drain the Great Lakes, the maximum drainage area is 8,288 square miles (Hudson River at Albany). Most data were obtained from U.S. Geological Survey (USGS) compilations and records, but some were provided by State, local, and other Federal agencies and by private organizations. The stage and discharge information is grouped by major drainage basins and U.S. Geological Survey site number, in downstream order. Site locations and their associated drainage area, period(s) of record, stage and discharge data, and flood-frequency statistics are compiled in a Microsoft Excel spreadsheet. Flood frequencies were derived for 1,238 sites by using methods described in Bulletin 17B (Interagency Advisory Committee on Water Data, 1982), Ries and Crouse (2002), and Lumia and others (2006). Curves that “envelope” maximum discharges within their range of drainage areas were developed for each of six flood-frequency hydrologic regions and for sites on Long Island, as well as for the State of New York; the New York curve was compared with a curve derived from a plot of maximum known discharges throughout the United States. Discharges represented by the national curve range from at least 2.7 to 4.9 times greater than those represented by the New York curve for drainage areas of 1.0 and 1,000 square miles. The relative magnitudes of discharge and runoff in the six hydrologic regions of New York and Long Island suggest the largest known discharges per square mile are in the southern part of western New York and the Catskill Mountain area, and the smallest are on Long Island.

A randomized trial of early versus delayed mediastinal drain removal after cardiac surgery using silastic and conventional tubes

PubMed Central

Moss, Emmanuel; Miller, Corey S.; Jensen, Henrik; Basmadjian, Arsène; Bouchard, Denis; Carrier, Michel; Perrault, Louis P.; Cartier, Raymond; Pellerin, Michel; Demers, Philippe

2013-01-01

OBJECTIVES Mediastinal drainage following cardiac surgery with traditional large-bore plastic tubes can be painful and cumbersome. This study was designed to determine whether prolonged drainage (5 days) with a silastic tube decreased the incidence of significant pericardial effusion and tamponade following aortic or valvular surgery. METHODS One hundred and fifty patients undergoing valvular or aortic surgery in a tertiary cardiac surgery institution were randomized to receive a conventional mediastinal tube plus a silastic Blake drain (n = 75), or two conventional tubes (n = 75). Conventional drains were removed on postoperative day (POD) 1, while Blake drains were removed on POD 5. The primary end-point was the combined incidence of significant pericardial effusion (≥15 mm) or tamponade through POD 5. Secondary end-points included total mediastinal drainage, postoperative atrial fibrillation (AF) and pain. RESULTS Analysis was performed for 67 patients in the Blake group and 73 in the conventional group. There was no difference between the two groups in the combined end-point of significant effusion or tamponade (7.4 vs 8.3%, P = 0.74), or in the incidence of AF (47 vs 46%, P = 0.89). Mean 24-h drainage was greater in the Blake group than in the conventional group (749 ± 444 ml vs 645 ± 618 ml, P < 0.01). Overall incidence of significant pericardial effusion at 30 days was 12.1% (n = 17), with 5% (n = 7) requiring drainage. The Blake group had a numerically lower incidence of effusion requiring drainage at POD 30 (3.0 vs 6.8%, P = 0.44). Postoperative pain was similar between groups. CONCLUSIONS In patients undergoing ascending aortic or valvular surgery, prolonged drainage with silastic tubes is safe and does not increase postoperative pain. There was no difference between the Blake and conventional drains with regard to significant pericardial effusion or tamponade in this cohort; however, this conclusion is limited by the low overall incidence of the primary outcome in this cohort. PMID:23575759

Study of treatment results and early complications of tube drainage versus capitonnage after the unroofing and aspiration of hydatid cysts.

PubMed

Mehrabi Bahar, Mostafa; Jabbari Nooghabi, Azadeh; Hamid, Alireza; Amouzeshi, Ahmad; Jangjoo, Ali

2014-10-01

There is controversy concerning the management of the remaining cavity after the evacuation of a cyst in patients who have undergone surgical operation for liver hydatidosis. This study compares the results of capitonnage and tube drainage of the remaining cavity. In this retrospective study, participants were selected from two groups of patients with a liver hydatid cyst who underwent capitonnage or tube drainage from 2004 to 2012. The patients were followed for 6-24 months. The data of age, sex, involved liver lobe, size of the cyst, complications, drain duration, and hospital stay were analyzed. Participants included 155 patients consisting of 96 (61.94%) females and 59 (38.06%) males. Most cysts were in the right lobe, and the most common diameter of the cysts was greater than 10 cm. Capitonnage was performed on 90 (58.06%) patients and the tube drainage procedure was performed on the remaining 65 (41.94%) patients. In the tube drainage group and the capitonnage group, the operative times were 2.21 ± 0.65 hours and 2.53 ± 0.35 hours, respectively; the hospital stays were 5.695 ± 3.37 days and 4.43 ± 2.96 days, respectively; the drain duration was 9.2 ± 1.7 days and 2.1 ± 0.4 days, respectively; and the time to return to work was 14.7 ± 2.3 days and 8.3 ± 10.4 days, respectively. All variables were statistically significant, except for the operative time. Cavity infection and biliary fistula were identified in three patients and six patients, respectively, in the tube drainage group and identified in two patients and three patients, respectively, in the capitonnage group. This difference was not statistically significant. This study demonstrated that capitonnage versus the tube drainage method may result in a shorter hospital stay, decreased time to return to work, and low rate of morbidity and complications. Copyright © 2014. Published by Elsevier B.V.

GIS based quantitative morphometric analysis and its consequences: a case study from Shanur River Basin, Maharashtra India

NASA Astrophysics Data System (ADS)

Pande, Chaitanya B.; Moharir, Kanak

2017-05-01

A morphometric analysis of Shanur basin has been carried out using geoprocessing techniques in GIS. These techniques are found relevant for the extraction of river basin and its drainage networks. The extracted drainage network was classified according to Strahler's system of classification and it reveals that the terrain exhibits dendritic to sub-dendritic drainage pattern. Hence, from the study, it is concluded that remote sensing data (SRTM-DEM data of 30 m resolution) coupled with geoprocessing techniques prove to be a competent tool used in morphometric analysis and evaluation of linear, slope, areal and relief aspects of morphometric parameters. The combined outcomes have established the topographical and even recent developmental situations in basin. It will also change the setup of the region. It therefore needs to analyze high level parameters of drainage and environment for suitable planning and management of water resource developmental plan and land resource development plan. The Shanur drainage basin is sprawled over an area of 281.33 km2. The slope of the basin varies from 1 to 10 %, and the slope variation is chiefly controlled by the local geology and erosion cycles. The main stream length ratio of the basin is 14.92 indicating that the study area is elongated with moderate relief and steep slopes. The morphometric parameters of the stream have been analyzed and calculated by applying standard methods and techniques viz. Horton (Trans Am Geophys Union 13:350-361, 1945), Miller (A quantitative geomorphologic study of drainage basin characteristics in the clinch mountain area, Virginia and Tennessee Columbia University, Department of Geology, Technical Report, No. 3, Contract N6 ONR 271-300, 1953), and Strahler (Handbook of applied hydrology, McGraw Hill Book Company, New York, 1964). GIS based on analysis of all morphometric parameters and the erosional development of the area by the streams has been progressed well beyond maturity and lithology is an influence in the drainage development. These studies are very useful for planning of rainwater harvesting and watershed management.

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

Subsurface drainage volume reduction with drainage water management: Case studies in Ohio, USA

USDA-ARS?s Scientific Manuscript database

One of the main contributors to poor water quality in the Mississippi River and aeral increase in the hypoxic zone in the Gulf of Mexico is intensive drainage of the cropland within the watershed. Controlled drainage has been demonstrated as an approach to curb totla drainage outflow and nutrient di...

Alternative methods to trench backfill.

DOT National Transportation Integrated Search

2005-04-30

Conduit structures dealing with hydraulic drainage needs in the Louisiana highway system include pipe culverts, pipe arch culverts, storm drains, sewers, etc. Although the Louisiana Department of Transportation and Development (LADOTD) has standard s...

Efficacy of preoperative biliary drainage in malignant obstructive jaundice: a meta-analysis and systematic review.

PubMed

Moole, Harsha; Bechtold, Matthew; Puli, Srinivas R

2016-07-11

In patients requiring surgical resection for malignant biliary jaundice, it is unclear if preoperative biliary drainage (PBD) would improve mortality and morbidity by restoration of biliary flow prior to operation. This is a meta-analysis to pool the evidence and assess the utility of PBD in patients with malignant obstructive jaundice. The primary outcome is comparing mortality outcomes in patients with malignant obstructive jaundice undergoing direct surgery (DS) versus PBD. The secondary outcomes include major adverse events and length of hospital stay in both the groups. Studies using PBD in patients with malignant obstructive jaundice were included in this study. For the data collection and extraction, articles were searched in MEDLINE, PubMed, Embase, Cochrane Central Register of Controlled Trials & Database of Systematic Reviews, etc. Pooled proportions were calculated using both Mantel-Haenszel method (fixed effects model) and DerSimonian-Laird method (random effects model). Initial search identified 2230 reference articles, of which 204 were selected and reviewed. Twenty-six studies (N = 3532) for PBD in malignant obstructive jaundice which met the inclusion criteria were included in this analysis. The odds ratio for mortality in PBD group versus DS group was 0.96 (95 % CI = 0.71 to 1.29). Pooled number of major adverse effects was lower in the PBD group at 10.40 (95 % CI = 9.96 to 10.83) compared to 15.56 (95 % CI = 15.06 to 16.05) in the DS group. Subgroup analysis comparing internal PBD to DS group showed lower odds for major adverse events (odds ratio, 0.48 with 95 % CI = 0.32 to 0.74). In patients with malignant biliary jaundice requiring surgery, PBD group had significantly less major adverse effects than DS group. Length of hospital stay and mortality rate were comparable in both the groups.

Managing the Earth’s Biggest Mass Gathering Event and WASH Conditions: Maha Kumbh Mela (India)

PubMed Central

Baranwal, Annu; Anand, Ankit; Singh, Ravikant; Deka, Mridul; Paul, Abhishek; Borgohain, Sunny; Roy, Nobhojit

2015-01-01

Background: Mass gatherings including a large number of people makes the planning and management of the event a difficult task. Kumbh Mela is one such, internationally famous religious mass gathering. It creates the substantial challenge of creating a temporary city in which millions of people can stay for a defined period of time. The arrangements need to allow this very large number of people to reside with proper human waste disposal, medical services, adequate supplies of food and clean water, transportation etc. Methods: We report a case study of Maha Kumbh, 2013 which focuses on the management and planning that went into the preparation of Kumbh Mela and understanding its water, sanitation and hygiene conditions. It was an observational cross-sectional study, the field work was done for 13 days, from 21 January to 2 February 2013. Results: Our findings suggest that the Mela committee and all other agencies involved in Mela management proved to be successful in supervising the event and making it convenient, efficient and safe. Health care services and water sanitation and hygiene conditions were found to be satisfactory. BhuleBhatke Kendra (Center for helping people who got separated from their families) had the major task of finding missing people and helping them to meet their families. Some of the shortfalls identified were that drainage was a major problem and some fire incidents were reported. Therefore, improvement in drainage facilities and reduction in fire incidents are essential to making Mela cleaner and safer. The number of persons per toilet was high and there were no separate toilets for males and females. Special facilities and separate toilets for men and women will improve their stay in Mela. Conclusion: Inculcation of modern methods and technologies are likely to help in supporting crowd management and improving water, sanitation and hygiene conditions in the continuously expanding KumbhMela, in the coming years. PMID:25932345

Endoscopic ultrasound guided drainage of pancreatic fluid collections: Assessment of the procedure, technical details and review of the literature

PubMed Central

Puri, Rajesh; Thandassery, Ragesh Babu; Alfadda, Abdulrahman A; Kaabi, Saad Al

2015-01-01

Endoscopic ultrasound (EUS) guided drainage of pancreatic fluid collections (PFC) has become increasingly popular and become first line management option in many centers. Use of therapeutic echoendoscopes has greatly increased the applicability of EUS guided transmural drainage. Drainage is indicated in symptomatic PFCs, PFC related infection, bleed, luminal obstruction, fistulization and biliary obstruction. EUS guided transmural drainage of PFCs is preferred in patients with non bulging lesions, portal hypertension, bleeding tendency and in those whom conventional drainage has failed. In the present decade significant progress has been made in minimally invasive endoscopic techniques. There are newer stent designs, access devices and techniques for more efficient drainage of PFCs. In this review, we discuss the EUS guided drainage of PFCs in acute pancreatitis. PMID:25901214

On the theory of drainage area for regular and non-regular points.

PubMed

Bonetti, S; Bragg, A D; Porporato, A

2018-03-01

The drainage area is an important, non-local property of a landscape, which controls surface and subsurface hydrological fluxes. Its role in numerous ecohydrological and geomorphological applications has given rise to several numerical methods for its computation. However, its theoretical analysis has lagged behind. Only recently, an analytical definition for the specific catchment area was proposed (Gallant & Hutchinson. 2011 Water Resour. Res. 47 , W05535. (doi:10.1029/2009WR008540)), with the derivation of a differential equation whose validity is limited to regular points of the watershed. Here, we show that such a differential equation can be derived from a continuity equation (Chen et al. 2014 Geomorphology 219 , 68-86. (doi:10.1016/j.geomorph.2014.04.037)) and extend the theory to critical and singular points both by applying Gauss's theorem and by means of a dynamical systems approach to define basins of attraction of local surface minima. Simple analytical examples as well as applications to more complex topographic surfaces are examined. The theoretical description of topographic features and properties, such as the drainage area, channel lines and watershed divides, can be broadly adopted to develop and test the numerical algorithms currently used in digital terrain analysis for the computation of the drainage area, as well as for the theoretical analysis of landscape evolution and stability.

On the theory of drainage area for regular and non-regular points

NASA Astrophysics Data System (ADS)

Bonetti, S.; Bragg, A. D.; Porporato, A.

2018-03-01

The drainage area is an important, non-local property of a landscape, which controls surface and subsurface hydrological fluxes. Its role in numerous ecohydrological and geomorphological applications has given rise to several numerical methods for its computation. However, its theoretical analysis has lagged behind. Only recently, an analytical definition for the specific catchment area was proposed (Gallant & Hutchinson. 2011 Water Resour. Res. 47, W05535. (doi:10.1029/2009WR008540)), with the derivation of a differential equation whose validity is limited to regular points of the watershed. Here, we show that such a differential equation can be derived from a continuity equation (Chen et al. 2014 Geomorphology 219, 68-86. (doi:10.1016/j.geomorph.2014.04.037)) and extend the theory to critical and singular points both by applying Gauss's theorem and by means of a dynamical systems approach to define basins of attraction of local surface minima. Simple analytical examples as well as applications to more complex topographic surfaces are examined. The theoretical description of topographic features and properties, such as the drainage area, channel lines and watershed divides, can be broadly adopted to develop and test the numerical algorithms currently used in digital terrain analysis for the computation of the drainage area, as well as for the theoretical analysis of landscape evolution and stability.

The use of deconvolution techniques to identify the fundamental mixing characteristics of urban drainage structures.

PubMed

Stovin, V R; Guymer, I; Chappell, M J; Hattersley, J G

2010-01-01

Mixing and dispersion processes affect the timing and concentration of contaminants transported within urban drainage systems. Hence, methods of characterising the mixing effects of specific hydraulic structures are of interest to drainage network modellers. Previous research, focusing on surcharged manholes, utilised the first-order Advection-Dispersion Equation (ADE) and Aggregated Dead Zone (ADZ) models to characterise dispersion. However, although systematic variations in travel time as a function of discharge and surcharge depth have been identified, the first order ADE and ADZ models do not provide particularly good fits to observed manhole data, which means that the derived parameter values are not independent of the upstream temporal concentration profile. An alternative, more robust, approach utilises the system's Cumulative Residence Time Distribution (CRTD), and the solute transport characteristics of a surcharged manhole have been shown to be characterised by just two dimensionless CRTDs, one for pre- and the other for post-threshold surcharge depths. Although CRTDs corresponding to instantaneous upstream injections can easily be generated using Computational Fluid Dynamics (CFD) models, the identification of CRTD characteristics from non-instantaneous and noisy laboratory data sets has been hampered by practical difficulties. This paper shows how a deconvolution approach derived from systems theory may be applied to identify the CRTDs associated with urban drainage structures.

[The impact of preoperative biliary drainage on surgical morbidity in hilar cholangiocarcinoma patients].

PubMed

Li, Shao-qiang; Chen, Dong; Liang, Li-jian; Peng, Bao-gang; Yin, Xiao-yu

2009-08-01

To evaluate the impact of preoperative biliary drainage on surgical morbidity in hilar cholangiocarcinoma patients underwent surgery. One hundred and eleven consecutive patients with hilar cholangiocarcinoma whose serum total bilirubin (TBIL) level > 85 micromol/L and underwent surgery in the period from June 1998 to August 2007 were enrolled. There were 67 male and 44 female patients, aged from 26 to 82 years old with a mean of 56 years old. Fifty-five patients underwent preoperative biliary drainage with a mean of 11.4 d of drainage period (drainage group), the other (n = 56) were the non-drainage group. The preoperative TBIL level of drainage group was (154 +/- 69) micromol/L, which was significantly lower than the value of pre-drainage (256 +/- 136) micromol/L (P = 0.000) and the value of non-drainage group (268 +/- 174) micromol/L (P = 0.005). ALT and GGT levels could be lowered by preoperative biliary drainage. The postoperative complications of these two groups were comparable (36.3% vs. 28.6%, P = 0.381). Four patients in drainage group and 5 patients in non-drainage group died of liver failure. Multivariate logistic regression indicated that hepatectomy (OR = 0.284, P = 0.003) was the independent risk factor associated with postoperative morbidity. Bismuth-Corlette classification (OR = 0.211, P = 0.028) was the independent risk factor linked to postoperative mortality. Preoperative biliary drainage could alleviate liver injury due to hyperbilirubin, but it could not decrease the surgical morbidity and postoperative mortality. Concomitant hepatectomy and Bismuth-Corlette classification were independent risk factors linked to surgical risks.

Assessment of the microbial community in a constructed wetland that receives acid coal mine drainage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicomrat, D.; Dick, W.A.; Tuovinen, O.H.

2006-01-15

Constructed wetlands are used to treat acid drainage from surface or underground coal mines. However, little is known about the microbial communities in the receiving wetland cells. The purpose of this work was to characterize the microbial population present in a wetland that was receiving acid coal mine drainage (AMD). Samples were collected from the oxic sediment zone of a constructed wetland cell in southeastern Ohio that was treating acid drainage from an underground coal mine seep. Samples comprised Fe(Ill) precipitates and were pretreated with ammonium oxalate to remove interfering iron, and the DNA was extracted and purified by agarosemore » gel electrophoresis prior to amplification of portions of the 16S rRNA gene. Amplified products were separated by denaturing gradient gel electrophoresis and DNA from seven distinct bands was excised from the gel and sequenced. The sequences were matched to sequences in the GenBank bacterial 16S rDNA database. The DNA in two of the bands yielded matches with Acidithiobacillus ferrooxidans and the DNA in each of the remaining five bands was consistent with one of the following microorganisms: Acidithiobacillus thiooxidans, strain TRA3-20 (a eubacterium), strain BEN-4 (an arsenite-oxidizing bacterium), an Alcaligenes sp., and a Bordetella sp. Low bacterial diversity in these samples reflects the highly inorganic nature of the oxic sediment layer where high abundance of iron- and sulfur-oxidizing bacteria would be expected. The results we obtained by molecular methods supported our findings, obtained using culture methods, that the dominant microbial species in an acid receiving, oxic wetland are A. thiooxidans and A. ferrooxidans.« less

Surgical Treatments for Infantile Purulent Meningitis Complicated by Subdural Effusion

PubMed Central

Wang, Xianshu; Zhang, Xiaoru; Cao, Hongbin; Jing, Shiyuan; Yang, Zhiguo; Cheng, Zhenghai; Liu, Ye; Li, Xin; Gao, Feifei; Ji, Yuanqi

2015-01-01

Background Infantile purulent meningitis (PM) is a commonly severe intracranial infectious disease in infants under age 1 year. In recent years, several diagnostic and treatment methods were reported, but in these cases the neurological complications and sequel were often observed, among which subdural effusion (SE) is the most common complication in PM. Timely diagnosis and early intervention are vital for better outcomes. In this study, the surgical treatments for infantile PM complicated by SE were investigated. Material/Methods Patients who had PM complicated by SE in the Children’s Hospital of Hebei Province from June 2000 to June 2012 were retrospectively analyzed and 170 patients were enrolled in the study. Surgical treatment for each patient was adopted according to producing effusion time, leucocyte count, protein content, intracranial pressure, and bacteria culture, coupled with cranial ultrasound examination, CT, and MRI scans. Results Nearly, 15 patients were cured using serial taps, with a 50% cure rate. Seventeen out of 30 (56.6%) patients receiving subcutaneous reservoir drainage had better outcome. Nearly 80% of patients (55/69) who underwent minimally invasive trepanation and drainage were positive. Surgical procedure of minimally invasive trepanation and drainage combined with drug douche was effective in 63% of patients (19/30). In addition, 6 patients were cured with subdural-peritoneal shunt. Only 1 patient died, after the recurrence of meningitis, and the remaining 4 patients were cured by craniotomy. Conclusions For infantile PM complicated with SE, treatment needs be chosen according to the specific situation. Surgical procedure of minimally invasive trepanation and drainage is a very effective treatment in curing PM complicated by SE. The treatment was highly effective with the use of drug douche. Subdural-peritoneal shunt and craniotomy were as effective as in refractory cases. PMID:26482715

Imaging Preferential Flow Pathways of Contaminants from Passive Acid Mine Drainage Mitigation Sites Using Electrical Resistivity

NASA Astrophysics Data System (ADS)

Kelley, N.; Mount, G.; Terry, N.; Herndon, E.; Singer, D. M.

2017-12-01

The Critical Zone represents the surficial and shallow layer of rock, air, water, and soil where most interactions between living organisms and the Earth occur. Acid mine drainage (AMD) resulting from coal extraction can influence both biological and geochemical processes across this zone. Conservative estimates suggest that more than 300 million gallons of AMD are released daily, making this acidic solution of water and contaminants a common issue in areas with legacy or current coal extraction. Electrical resistivity imaging (ERI) provides a rapid and minimally invasive method to identify and monitor contaminant pathways from AMD remediation systems in the subsurface of the Critical Zone. The technique yields spatially continuous data of subsurface resistivity that can be inverted to determine electrical conductivity as a function of depth. Since elevated concentrations of heavy metals can directly influence soil conductivity, ERI data can be used to trace the flow pathways or perhaps unknown mine conduits and transport of heavy metals through the subsurface near acid mine drainage sources. This study aims to examine preferential contaminant migration from those sources through substrate pores, fractures, and shallow mine workings in the near subsurface surrounding AMD sites in eastern Ohio and western Pennsylvania. We utilize time lapse ERI measures during different hydrologic conditions to better understand the variability of preferential flow pathways in relation to changes in stage and discharge within the remediation systems. To confirm ERI findings, and provide constraint to geochemical reactions occurring in the shallow subsurface, we conducted Inductively Coupled Plasma (ICP) spectrometry analysis of groundwater samples from boreholes along the survey transects. Through these combined methods, we can provide insight into the ability of engineered systems to contain and isolate metals in passive acid mine drainage treatment systems.

Simulation of flood hydrographs for Georgia streams

USGS Publications Warehouse

Inman, Ernest J.

1987-01-01

Flood hydrographs are needed for the design of many highway drainage structures and embankments. A method for simulating these flood hydrographs at ungaged sites in Georgia is presented in this report. The O'Donnell method was used to compute unit hydrographs and lagtimes for 355 floods at 80 gaging stations. An average unit hydrograph and an average lagtime were computed for each station. These average unit hydrographs were transformed to unit hydrographs having durations of one-fourth, one-third, one-half, and three-fourths lagtime, then reduced to dimensionless terms by dividing the time by lagtime and the discharge by peak discharge. Hydrographs were simulated for these 355 floods and their widths were compared with the widths of the observed hydrographs at 50 and 75 percent of peak flow. The dimensionless hydrograph based on one-half lagtime duration provided the best fit of the observed data. Multiple regression analysis was then used to define relations between lagtime and certain physical basin characteristics; of these characteristics, drainage area and slope were found to be significant for the rural-stream equations and drainage area, slope, and impervious area were found to be significant for the Atlanta urban-stream equation. A hydrograph can be simulated from the dimensionless hydrograph, the peak discharge of a specific recurrence interval, and the lagtime obtained from regression equations for any site in Georgia having a drainage area of less than 500 square miles. For simulating hydrographs at sites having basins larger than 500 square miles, the U.S. Geological Survey computer model CONROUT can be used. This model routes streamflow from an upstream channel location to a user-defined location downstream. The product of CONROUT is a simulated discharge hydrograph for the downstream site that has a peak discharge of a specific recurrence interval.

Moss and soil contributions to the annual net carbon flux of a maturing boreal forest

USGS Publications Warehouse

Harden, J.W.; O'Neill, K. P.; Trumbore, S.E.; Veldhuis, H.; Stocks, B.J.

1997-01-01

We used input and decomposition data from 14C studies of soils to determine rates of vertical accumulation of moss combined with carbon storage inventories on a sequence of burns to model how carbon accumulates in soils and moss after a stand-killing fire. We used soil drainage - moss associations and soil drainage maps of the old black spruce (OBS) site at the BOREAS northern study area (NSA) to areally weight the contributions of each moderately well drained, feathermoss areas; poorly drained sphagnum - feathermoss areas; and very poorly drained brown moss areas to the carbon storage and flux at the OBS NSA site. On this very old (117 years) complex of black spruce, sphagnum bog veneer, and fen systems we conclude that these systems are likely sequestering 0.01-0.03 kg C m-2 yr-' at OBS-NSA today. Soil drainage in boreal forests near Thompson, Manitoba, controls carbon storage and flux by controlling moss input and decomposition rates and by controlling through fire the amount and quality of carbon left after burning. On poorly drained soils rich in sphagnum moss, net accumulation and long-term storage of carbon is higher than on better drained soils colonized by feathermosses. The carbon flux of these contrasting ecosystems is best characterized by soil drainage class and stand age, where stands recently burned are net sources of CO2, and maturing stands become increasingly stronger sinks of atmospheric CO2. This approach to measuring carbon storage and flux presents a method of scaling to larger areas using soil drainage, moss cover, and stand age information.

Simplified continuous simulation model for investigating effects of controlled drainage on long-term soil moisture dynamics with a shallow groundwater table.

PubMed

Sun, Huaiwei; Tong, Juxiu; Luo, Wenbing; Wang, Xiugui; Yang, Jinzhong

2016-08-01

Accurate modeling of soil water content is required for a reasonable prediction of crop yield and of agrochemical leaching in the field. However, complex mathematical models faced the difficult-to-calibrate parameters and the distinct knowledge between the developers and users. In this study, a deterministic model is presented and is used to investigate the effects of controlled drainage on soil moisture dynamics in a shallow groundwater area. This simplified one-dimensional model is formulated to simulate soil moisture in the field on a daily basis and takes into account only the vertical hydrological processes. A linear assumption is proposed and is used to calculate the capillary rise from the groundwater. The pipe drainage volume is calculated by using a steady-state approximation method and the leakage rate is calculated as a function of soil moisture. The model is successfully calibrated by using field experiment data from four different pipe drainage treatments with several field observations. The model was validated by comparing the simulations with observed soil water content during the experimental seasons. The comparison results demonstrated the robustness and effectiveness of the model in the prediction of average soil moisture values. The input data required to run the model are widely available and can be measured easily in the field. It is observed that controlled drainage results in lower groundwater contribution to the root zone and lower depth of percolation to the groundwater, thus helping in the maintenance of a low level of soil salinity in the root zone.

Studies on Foam Decay Trend and Influence of Temperature Jump on Foam Stability in Sclerotherapy.

PubMed

Bai, Taoping; Chen, Yu; Jiang, Wentao; Yan, Fei; Fan, Yubo

2018-02-01

This study investigated the influence of temperature jump and liquid-gas ratio on foam stability to derive the foam-decay law. The experimental group conditions were as follows: mutation temperatures (10°C, 16°C, 20°C, 23°C, 25°C, and 27°C to >37°C) and liquid-gas ratios (1:1, 1:2, 1:3, and 1:4). The control group conditions were as follows: temperatures (10°C, 16°C, 20°C, 23°C, 25°C and 27°C) and liquid-gas ratios (1:1, 1:2, 1:3, and 1:4). A homemade device manufactured using the Tessari DSS method was used to prepare the foam. The decay process was videotape recorded. In the drainage rate curve, the temperature rose, and the liquid-gas ratio varied from 1:1 to 1:4, causing faster decay. In the entire process, the foam volume decreased with increasing drainage rate. The relationships were almost linear. Comparison of the experimental and control groups shows that the temperature jump results in a drainage time range of 1 to 15 seconds. The half-life ranges from 10 to 30 seconds. The maximum rate is 18.85%. Changes in the preparation temperature yields a drainage time range of 3 to 30 seconds. The half-life varies from 20 to 60 seconds. Decreasing the temperature jump range and liquid-gas ratio gradually enhances the foam stability. The foam decay time and drainage rate exhibit an exponential function distribution.

Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

NASA Astrophysics Data System (ADS)

Livingstone, S. J.; Clark, C. D.; Woodward, J.; Kingslake, J.

2013-11-01

We use the Shreve hydraulic potential equation as a simplified approach to investigate potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. We validate the method by demonstrating its ability to recall the locations of >60% of the known subglacial lakes beneath the Antarctic Ice Sheet. This is despite uncertainty in the ice-sheet bed elevation and our simplified modelling approach. However, we predict many more lakes than are observed. Hence we suggest that thousands of subglacial lakes remain to be found. Applying our technique to the Greenland Ice Sheet, where very few subglacial lakes have so far been observed, recalls 1607 potential lake locations, covering 1.2% of the bed. Our results will therefore provide suitable targets for geophysical surveys aimed at identifying lakes beneath Greenland. We also apply the technique to modelled past ice-sheet configurations and find that during deglaciation both ice sheets likely had more subglacial lakes at their beds. These lakes, inherited from past ice-sheet configurations, would not form under current surface conditions, but are able to persist, suggesting a retreating ice-sheet will have many more subglacial lakes than advancing ones. We also investigate subglacial drainage pathways of the present-day and former Greenland and Antarctic ice sheets. Key sectors of the ice sheets, such as the Siple Coast (Antarctica) and NE Greenland Ice Stream system, are suggested to have been susceptible to subglacial drainage switching. We discuss how our results impact our understanding of meltwater drainage, basal lubrication and ice-stream formation.

Hydrologic and water-quality data in selected agricultural drainages in Beaufort and Hyde Counties, North Carolina, 1990-92

USGS Publications Warehouse

Treece, M.W.

1993-01-01

An investigation was begun in 1988 to: (1) quantify nutrient, sediment, and freshwater loadings in canals that collect drainage from cropland field ditches; (2) determine the effects of tide gates and flashboard risers on these loadings and on receiving water quality; and (3) characterize the effects of drainage on the salinity regime of a tidal creek. Data were collected in three canals in Hyde County, two canals in Beaufort County, and in Campbell Creek, which receives drainage directly from the Beaufort County canals. A tide gate was placed in one of the Hyde County canals near the beginning of the investigation. In August 1990 following more than 2 years of data collection, control structures were placed in the remaining two Hyde County canals. Flashboard risers were installed in the Beaufort County canals in April 1991. Hydrologic and water quality data are presented for each of the study sites for the period of October 1990 through May 1992. Following a description of the study sites and data collection methods, data are presented for the five drainage canals and Campbell Creek. The data collected included: (1) daily values of accumulated precipitation; (2) water level statistics; (3) daily mean values of discharge in the canals; (4) biweekly water quality measurements and sample analyses; (5) storm-event water quality measurements and sample analyses; (6) continuous records of specific conductance in the canals; (7) vertical profiles of salinity in Campbell Creek; and (8) daily mean values of salinity at five sites at Campbell Creek.

Losses of Soil Carbon upon a Fire on a Drained Forested Raised Bog

NASA Astrophysics Data System (ADS)

Glukhova, T. V.; Sirin, A. A.

2018-05-01

We studied the consequences of a fire that affected 29 ha of a drained forested raised bog in Tver oblast, Central European Russia. The drainage network consisted of open 1-m-deep ditches with 60 to 160 m ditch spacing. The groundwater level (GWL) varied within the studied drained bog. We used the method of assessing the loss of soil carbon (C) based on the difference between the ash concentration in the burnt peat of the upper layer and underlying unburnt layers. The carbon loss was higher near the drainage ditches than in the sites remote from ditches. The sample median values of carbon loss (kg C/m2) were estimated at 0.37 near the drainage ditches and at 0.22 for the remote sites with a distance of 160 m between ditches. They increased to 2.23 and 0.79 near and far from the drainage ditches for 106 m ditch spacing, and ranged from 1.13 to 2.10 near the drainage ditches and were equal to 0.45 at the remote sites for 60 m ditch spacing. The maximum loss of C was at the bog margin with the 70-cm-deep GWL; the sample median was equal to 2.97 kg C/m2. The results obtained for C loss from the wildfire on the raised bog agree with the estimates obtained by other authors (1.45-4.90 kg C/m2) and confirm the importance of taking such loss into account in the estimates of the carbon budget of peat soils (Histosols).

Multistage late Cenozoic evolution of the Amargosa River drainage, southwestern Nevada and eastern California Society of America. All rights reserved

USGS Publications Warehouse

Menges, C.M.

2008-01-01

Stratigraphic and geomorphic analyses reveal that the regional drainage basin of the modern Amargosa River formed via multistage linkage of formerly isolated basins in a diachronous series of integration events between late Miocene and latest Pleistocene-Holocene time. The 275-km-long Amargosa River system drains generally southward across a large (15,540 km ²) watershed in southwestern Nevada and eastern California to its terminus in central Death Valley. This drainage basin is divided into four major subbasins along the main channel and several minor subbasins on tributaries; these subbasins contain features, including central valley lowlands surrounded by highlands that form external divides or internal paleodivides, which suggest relict individual physiographic-hydrologic basins. From north to south, the main subbasins along the main channel are: (1) an upper headwaters subbasin, which is deeply incised into mostly Tertiary sediments and volcanic rocks; (2) an unincised low-gradient section within the Amargosa Desert; (3) a mostly incised section centered on Tecopa Valley and tributary drainages; and (4) a west- to northwest-oriented mostly aggrading lower section along the axis of southern Death Valley. Adjoining subbasins are hydro-logically linked by interconnecting narrows or canyon reaches that are variably incised into formerly continuous paleodivides. The most important linkages along the main channel include: (1) the Beatty narrows, which developed across a Tertiary bedrock paleodivide between the upper and Amargosa Desert subbasins during a latest Miocene-early Pliocene to middle Pleistocene interval (ca. 4-0.5 Ma); (2) the Eagle Mountain narrows, which cut into a mostly alluvial paleodivide between the Amar-gosa Desert and Tecopa subbasins in middle to late Pleistocene (ca. 150-100 ka) time; and (3) the Amargosa Canyon, which formed in late middle Pleistocene (ca. 200140 ka) time through a breached, actively uplifting paleodivide between the Tecopa and southern Death Valley subbasins. Collectively, the interconnecting reaches represent discrete integration events that incrementally produced the modern drainage basin starting near Beatty sometime after 4 Ma and ending in the Salt Creek tributary in the latest Pleistocene to Holocene (post-30 ka). Potential mechanisms for drainage integration across paleodivides include basin overtopping from sedimentary infilling above paleodivide elevations, paleolake spillover, groundwater sapping, and (or) headward erosion of dissecting channels in lower-altitude subbasins. These processes are complexly influenced by fluvial responses to factors such as climatic change, local base-level differences across divides, and (or) tectonic activity (the latter only recognized in Amargosa Canyon). ?? 2008 The Geological Society of America.

Drainage capture and discharge variations driven by glaciation in the Southern Alps, New Zealand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ann V. Rowan; Mitchell A. Plummer; Simon H. Brocklehurst

Sediment flux in proglacial fluvial settings is primarily controlled by discharge, which usually varies predictably over a glacial–interglacial cycle. However, glaciers can flow against the topographic gradient to cross drainage divides, reshaping fluvial drainage networks and dramatically altering discharge. In turn, these variations in discharge will be recorded by proglacial stratigraphy. Glacial-drainage capture often occurs in alpine environments where ice caps straddle range divides, and more subtly where shallow drainage divides cross valley floors. We investigate discharge variations resulting from glacial-drainage capture over the past 40 k.y. for the adjacent Ashburton, Rangitata, and Rakaia basins in the Southern Alps, Newmore » Zealand. Although glacial-drainage capture has previously been inferred in the range, our numerical glacier model provides the first quantitative demonstration that this process drives larger variations in discharge for a longer duration than those that occur due to climate change alone. During the Last Glacial Maximum, the effective drainage area of the Ashburton catchment increased to 160% of the interglacial value with drainage capture, driving an increase in discharge exceeding that resulting from glacier recession. Glacial-drainage capture is distinct from traditional (base level–driven) drainage capture and is often unrecognized in proglacial deposits, complicating interpretation of the sedimentary record of climate change.« less

Assessment of the service performance of drainage system and transformation of pipeline network based on urban combined sewer system model.

PubMed

Peng, Hai-Qin; Liu, Yan; Wang, Hong-Wu; Ma, Lu-Ming

2015-10-01

In recent years, due to global climate change and rapid urbanization, extreme weather events occur to the city at an increasing frequency. Waterlogging is common because of heavy rains. In this case, the urban drainage system can no longer meet the original design requirements, resulting in traffic jams and even paralysis and post a threat to urban safety. Therefore, it provides a necessary foundation for urban drainage planning and design to accurately assess the capacity of the drainage system and correctly simulate the transport effect of drainage network and the carrying capacity of drainage facilities. This study adopts InfoWorks Integrated Catchment Management (ICM) to present the two combined sewer drainage systems in Yangpu District, Shanghai (China). The model can assist the design of the drainage system. Model calibration is performed based on the historical rainfall events. The calibrated model is used for the assessment of the outlet drainage and pipe loads for the storm scenario currently existing or possibly occurring in the future. The study found that the simulation and analysis results of the drainage system model were reliable. They could fully reflect the service performance of the drainage system in the study area and provide decision-making support for regional flood control and transformation of pipeline network.

Pseudocyst in the pancreatic tail associated with chronic pancreatitis successfully treated by transpapillary cyst drainage.

PubMed

Naitoh, Itaru; Ohara, Hirotaka; Okayama, Yasutaka; Nakazawa, Takahiro; Ando, Tomoaki; Hayashi, Kazuki; Okumura, Fumihiro; Kitajima, Yasuhiro; Ban, Tessin; Miyabe, Katsuyuki; Ueno, Koichiro; Joh, Takashi; Sano, Hitoshi

2008-09-01

We report a 50-year-old male with pseudocysts in the pancreatic tail associated with chronic pancreatitis successfully treated by transpapillary cyst drainage. He had previously undergone ultrasonography-guided percutaneous cyst drainage for a pancreatic pseudocyst in our hospital. He was readmitted due to abdominal pain and fever. Computed tomography showed recurrence of a pseudocyst in the pancreatic tail measuring 5 cm in diameter. Since conservative treatment failed, endoscopic retrograde pancreatography was performed. There was communication between the pseudocyst and the main pancreatic duct, and pancreatic duct stenosis proximal to the pseudocyst. First, transpapillary pancreatic duct drainage was performed using a plastic stent, but the pseudocyst did not decrease in size and became infected. After removal of the stent, a pigtail type nasocystic catheter was placed in the pseudocyst via the pancreatic duct. The pseudocyst infection immediately disappeared, and the pseudocyst gradually decreased and disappeared. After removal of the nasocystic catheter, no recurrence was observed. As transpapillary drainage of pancreatic pseudocyst, cyst drainage and pancreatic duct drainage have been reported. In our patient with pseudocyst in the pancreatic tail, duct drainage was ineffective and the pseudocyst was infected, whereas cyst drainage was very effective. We considered that cyst drainage by a nasocystic catheter was the first-line therapy as the transpapillary drainage of the pancreatic pseudocyst.

Inventory of drainage wells and potential sources of contaminants to drainage-well inflow in Southwest Orlando, Orange County, Florida

USGS Publications Warehouse

Taylor, George Fred

1993-01-01

Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.

[Application research of presacral space drainage tube combined with subcutaneous vacuum pressure suction in the laparoscopic-assisted abdominoperineal resection].

PubMed

Chen, Liqi; Zeng, Changqing; Chi, Liangjie; Huang, Liangxiang; Li, Jiandang

2017-08-25

To study the management for the perineal incision after laparoscopic-assisted abdominoperineal resection for rectal cancer. Clinical data of 87 patients undergoing laparoscopic Miles operation for lower rectal cancer from June 2009 to February 2014 were collected and studied. Presacral space drainage group: presacral space drainage tube was applied in 42 patients. Combined drainage group: presacral space drainage tube combined with subcutaneous vacuum pressure suction was applied in 45 cases. In combined drainage group, except the presacral drainage tube, another drainage tube was placed subcutaneously and connected to a negative pressure ball, which was fixed on the lateral anterior of perineal wound by the further incision and drainage. After subcutaneous tube was placed for 2 weeks, as drainage fluid was limpid and <15 ml/d for 3 days, meanwhile no obvious pelvic fluid was detected by ultrasound, and the wound healed quite well without redness and edema, then the subcutaneous tube with the negative pressure ball could be removed. There were 51 males and 36 females with the mean age of 26-78(56.9±10.8) years old. The laparoscopic Miles operation was successfully completed in all the cases without death and complications. The drainage tube was placed for 4-13(8.0±2.5) days in presacral space drainage group, and for 4-14(6.7±2.4) days in combined drainage group. The subcutaneous tube was placed for 14-24(15.8±3.0) days. The primary healing rate of perineal wound in presacral space drainage group and combined drainage group was 66.7%(28/42) and 91.1%(41/45) respectively, while the perineal wound infection rate was 21.4%(9/42) and 4.4%(2/45) respectively, whose differences between two groups were both significant (χ 2 =7.911, P=0.005 and χ 2 =5.674, P=0.017). Presacral space drainage tube combined with subcutaneous vacuum pressure suction in laparoscopic-assisted abdominoperineal resection for rectal cancer has better efficacy and lower infection rate for perineal incision, which is worth wide application.

43 CFR 23.7 - Approval of exploration plan.

Code of Federal Regulations, 2010 CFR

2010-10-01

... showing topographic, cultural and drainage features; (3) A statement of proposed exploration methods, i.e... measures to be taken to prevent or control fire, soil erosion, pollution of surface and ground water...

ODOT research news : spring 2005.

DOT National Transportation Integrated Search

2005-01-01

The newsletter includes: : 1) New Projects Selected; : 2) Commercial Products R&D Program; : 3) Managing a Multitude of Drainage Facilities; : 4) ODOT Helps with Seismography Network; : 5) Methods for Inspecting Composite-Strengthened Bridges; : 6) O...

[Choice of the method of surgical treatment of chronic pancreatitis].

PubMed

Vorobeĭ, A V; Shuleĭko, A Ch; Orlovskiĭ, Iu N; Vizhinis, Iu I; Butra, Iu V; Lagodich, N A

2014-01-01

An analysis of surgical treatment of 187 patients with chronic pancreatitis was made during 3-year period in the department of surgery clinic of Byelorussian Medical Academy of Post-Graduate Education. Drainage operations were performed on 28 patients, resection-drainage operations were carried out on 130 patients and resection operations had 19 patients. The laser beam technologies were successfully applied during operations on the pancreas in 43 patients. Postoperative complications (14.8%) were analyzed and structured. Methods of corrections and ways of prophylaxis of complication development were provided. On the basis of the complication analysis and new conception concerning peripheral pancreatic hypertension the authors offered the rational approaches to choice of operations on the pancreas in case of chronic pancreatitis. The authors developed the classification of pancreatoductolitiasis, pancreatic hypertension and a new strategy of surgical management of chronic pancreatitis.

Foam property tests to evaluate the potential for longwall shield dust control.

PubMed

Reed, W R; Beck, T W; Zheng, Y; Klima, S; Driscoll, J

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration's lower coal mine respirable dust standard of 1.5 mg/m 3 . Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control.

Foam property tests to evaluate the potential for longwall shield dust control

PubMed Central

Reed, W.R.; Beck, T.W.; Zheng, Y.; Klima, S.; Driscoll, J.

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration’s lower coal mine respirable dust standard of 1.5 mg/m3. Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control. PMID:29416179

Mortality of Dandy-Walker syndrome in the United States: Analysis by race, gender, and insurance status

PubMed Central

McClelland, Shearwood; Ukwuoma, Onyinyechi I.; Lunos, Scott; Okuyemi, Kolawole S.

2015-01-01

Background: Dandy-Walker syndrome (DWS) is a congenital disorder often diagnosed in early childhood. Typically manifesting with signs/symptoms of increased intracranial pressure, DWS is catastrophic unless timely neurosurgical care can be administered via cerebrospinal fluid (CSF) drainage. The rates of mortality, adverse discharge disposition (ADD), and CSF drainage in DWS may not be uniform regardless of race, gender or insurance status; such differences could reflect disparities in access to neurosurgical care. This study examines these issues on a nationwide level. Materials and Methods: The Kids’ Inpatient Database spanning 1997-2003 was used for analysis. Only patients admitted for DWS (ICD-9-CM = 742.3) were included. Multivariate analysis was adjusted for several variables, including patient age, race, sex, admission type, primary payer, income, and hospital volume. Results: More than 14,000 DWS patients were included. Increasing age predicted reduced mortality (OR = 0.87; P < 0.05), ADD (OR = 0.96; P < 0.05), and decreased likelihood of receiving CSF drainage (OR = 0.86; P < 0.0001). Elective admission type predicted reduced mortality (OR = 0.29; P = 0.0008), ADD (OR = 0.68; P < 0.05), and increased CSF drainage (OR = 2.02; P < 0.0001). African-American race (OR = 1.20; P < 0.05) and private insurance (OR = 1.18; P < 0.05) each predicted increased likelihood of receiving CSF drainage, but were not predictors of mortality or ADD. Gender, income, and hospital volume were not significant predictors of DWS outcome. Conclusion: Increasing age and elective admissions each decrease mortality and ADD associated with DWS. African-American race and private insurance status increase access to CSF drainage. These findings contradict previous literature citing African-American race as a risk factor for mortality in DWS, and emphasize the role of private insurance in obtaining access to potentially lifesaving operative care. PMID:25883477

Fast-Track Management of Patients Undergoing Proximal Pancreatic Resection

PubMed Central

French, JJ; Mansfield, SD; Jaques, K; Jaques, BC; Manas, DM; Charnley, RM

2009-01-01

INTRODUCTION To avoid the risk of complications of biliary drainage, a feasibility study was carried out to determine whether it might be possible to fast-track surgical treatment, with resection before biliary drainage, in jaundiced patients with proximal pancreatic/peri-ampullary malignancy. PATIENTS AND METHODS Over an 18-month period, based on their presenting bilirubin levels and other logistical factors, all jaundiced patients who might be suitable for fast-track management were identified. Data on complications and hospital stay were compared with those patients in whom a conventional pathway (with biliary drainage) was used during the same time period. Data were also compared with a group of patients from the preceding 6 months. RESULTS Nine patients were fast-tracked and 49 patients treated in the conventional pathway. Fast-track patients mean (SD) serum bilirubin level was 265 μmol/l (81.6) at the time of the operation compared to 43 μmol/l (51.3; P ≥ 0.0001) in conventional patients. Mean (SD) of time from referral to operation, 14 days (9) versus 59 days (36.9), was significantly shorter in fast-track patients than conventional patients (P ≤ 0.0001). Length of hospital stay mean (SD) at 17 (6) days versus 22 days (19.6; P = 0.2114), surgical complications and mortality in fast-track patients were similar to conventional patients. Prior to surgery, the 49 conventional patients underwent a total of 73 biliary drainage procedures resulting in seven major complications. Comparison with the group of patients from the previous 6 months indicated that the conventional group were not disadvantaged. CONCLUSIONS Fast-track management by resection without biliary drainage of selected patients with distal biliary strictures is safe and has the potential to reduce the waiting time to surgery, overall numbers of biliary drainage procedures and the complications thereof. PMID:19220943

Middlemore Hospital experience with tubo-ovarian abscesses: an observational retrospective study

PubMed Central

Habboub, Antoine Youssef

2016-01-01

Aim The aim of this paper was to study the characteristics of patients presenting to Middlemore Hospital with tubo-ovarian abscess (TOA) and to compare the outcomes of conservative medical management versus medical management with surgical drainage and medical management with radiological drainage. Methods All patients admitted with a radiologically or surgically proven TOA between January 01, 2008 and December 31, 2010, were included and followed up until June 30, 2011. The total number of patient/index admission was 174. Results The mean age of patients was 37.8 years. One hundred thirty patients had medical treatment only with hospitalization and antibiotics, and 44 patients were managed with antibiotics and surgical drainage. Complete resolution of TOA was 77.3% (99/128) for patients managed medically and 93.2% (41/44) for patients managed surgically. When the two groups were compared, patients who were managed surgically were more likely to have complete resolution of TOA within 6 months of index admission with an odds ratio (OR) of 4 and a P-value of 0.029. There was no statistically significant difference in the secondary outcomes namely of readmission with TOA (OR: 0.47) and the need for repeat surgical or radiological drainage (OR: 1.48). Nonetheless, the relative duration of hospitalization was longer for the surgical group with a P-value of <0.0001. The C-reactive protein and the size of TOA were the significant factors involved in the resolution of TOA. Conclusion The results of this study confirmed our initial hypothesis that we should consider surgical drainage more often, probably earlier, especially for the younger patients still desiring fertility preservation and for larger abscesses. Laparoscopic surgical drainage is safe and could be used as the procedure of choice. Conservative medical management is still acceptable with good cure rates of 77%. C-reactive protein and the size of the abscess were the important factors to consider when managing patients with TOA. PMID:27524920

Modeling of subglacial hydrological development following rapid supraglacial lake drainage.

PubMed

Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindbäck, K; Pettersson, R; Jones, G A; Hubbard, A

2015-06-01

The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections. Model for subglacial hydrological analysis of rapid lake drainage eventsLimited subglacial channel growth during and following rapid lake drainagePersistence of distributed drainage in inland areas where channel growth is limited.

Modeling of subglacial hydrological development following rapid supraglacial lake drainage

PubMed Central

Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindbäck, K; Pettersson, R; Jones, G A; Hubbard, A

2015-01-01

The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections. Key Points Model for subglacial hydrological analysis of rapid lake drainage events Limited subglacial channel growth during and following rapid lake drainage Persistence of distributed drainage in inland areas where channel growth is limited PMID:26640746

Composite fibrous glaucoma drainage implant

NASA Astrophysics Data System (ADS)

Klapstova, A.; Horakova, J.; Shynkarenko, A.; Lukas, D.

2017-10-01

Glaucoma is a frequent reason of loss vision. It is usually caused by increased intraocular pressure leading to damage of optic nerve head. This work deals with the development of fibrous structure suitable for glaucoma drainage implants (GDI). Commercially produced metallic glaucoma implants are very effective in lowering intraocular pressure. However, these implants may cause adverse events such as damage to adjacent tissue, fibrosis, hypotony or many others [1]. The aim of this study is to reduce undesirable properties of currently produced drains and improve their properties by creating of the composite fibrous drain for achieve a normal intraocular pressure. Two types of electrospinning technologies were used for the production of very small tubular implants. First type was focused for production of outer part of tubular drain and the second type of electrospinning method made the inner part of shape follows the connections of both parts. Complete implant had a special properties suitable for drainage of fluid. Morphological parameters, liquid transport tests and in-vitro cell adhesion tests were detected.

[Design of cross-sectional anatomical model focused on drainage pathways of paranasal sinuses].

PubMed

Zha, Y; Lv, W; Gao, Y L; Zhu, Z Z; Gao, Z Q

2018-05-01

Objective: To design and produce cross-sectional anatomical models of paranasal sinuses for the purpose of demonstrating drainage pathways of each nasal sinus for the young doctors. Method: We reconstructed the three-dimensional model of sinuses area based on CT scan data, and divided it into 5 thick cross-sectional anatomy models by 4 coronal plane，which cross middle points of agger nasi cell, ethmoid bulla, posterior ethmoid sinuses and sphenoid sinus respectively. Then a 3D printerwas used to make anatomical cross-sectional anatomical models. Result: Successfully produced a digital 3D printing cross-sectional models of paranasal sinuses. Sinus drainage pathways were observed on the models. Conclusion: The cross-sectional anatomical models made by us can exactly and intuitively demonstrate the ostia of each sinus cell and they can help the young doctors to understand and master the key anatomies and relationships which are important to the endoscopic sinus surgery. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Occult traumatic hemothorax: when can sleeping dogs lie?

PubMed

Bilello, John F; Davis, James W; Lemaster, Deborah M

2005-12-01

Size of traumatic occult hemothorax on admission requiring drainage has not been defined. Computed axial tomography (CAT) may guide drainage criteria. A retrospective review of patients with hemothoraces on CAT was performed. Extrapolating previously described methods of pleural fluid measurement, hemothoraces were quantified using the fluid stripe in the dependent pleural "gutter." Data included patient age, injury severity, and intervention (thoracentesis or tube thoracostomy). Seventy-eight patients with 99 occult hemothoraces met the criteria for study inclusion: 52 hemothoraces qualified as "minimal" and 47 as "moderate/large." Eight patients (15%) in the minimal group and 31 patients (66%) in the moderate/large group underwent intervention (P < .001). There was no difference in patient age, injury severity, ventilator requirement, or presence of pulmonary contusion. CAT in stable blunt-trauma patients can predict which patients with occult hemothorax are likely to undergo intervention. Patients with hemothorax > or = 1.5 cm on CAT were 4 times more likely to undergo drainage intervention compared with those having hemothorax < 1.5 cm.

The Global Geometry of River Drainage Basins and the Signature of Tectonic and Autogenic Processes

NASA Astrophysics Data System (ADS)

Giachetta, E.; Willett, S.

2015-12-01

The plan-form structure of the world's river basins contains extensive information regarding tectonic, paleo-geographic and paleo-climate conditions, but interpretation of this structure is complicated by the need to disentangle these processes from the autogenic behavior of fluvial processes. One method of interpreting this structure is by utilizing the well-established scaling between drainage area and channel slope. Integration of this scaling relationship predicts a relationship between channel length and downstream integrated drainage area, referred to in recent studies as χ (Willett et al., 2014). In this paper, we apply this methodology at a continental scale by calculating χ for the world's river networks using hydrological information from the HydroSHED (Hydrological data and maps based on SHuttleElevation Derivatives at multiple Scales) suite of geo-referenced data sets (drainage directions and flow accumulations). River pixels were identified using a minimum drainage area of 5 km2. A constant value of m/n of 0.45 was assumed. We applied a new method to correct χ within closed basins where base level is different from sea level. Mapping of χ illustrates the geometric stability of a river network, thus highlighting where tectonic or climatic forcing has perturbed the shape and geometry. Each continent shows characteristic features. Continental rift margins on all continents show clear asymmetric escarpments indicating inland migration. Active orogenic belts break up older river basins, but are difficult to interpret because of spatially variable uplift rates. Regions of recent tilting are evident even in cratonic areas by lateral reorganizations of basins. Past and pending river captures are identified on all continents. Very few regions on Earth appear to be in near-equilibrium, though some are identified; for example the Urals appears to provide a stable continental divide for Eurasia. Our analysis of maps of χ at the global scale quantifies a dynamic view of Earth's river networks and helps to identify past and ongoing evolution of Earth's landscapes. References Willett, S.D., McCoy, S.W., Perron, J.T., Goren, L., Chen C.Y. (2014): Dynamic reorganization of river basins, Science 343, 1248765. DOI: 10.1126/science.1248765.

Drainage and impregnation capillary pressure curves calculated by the X-ray CT model of Berea sandstone using Lattice Boltzmann's method

NASA Astrophysics Data System (ADS)

Zakirov, T.; Galeev, A.; Khramchenkov, M.

2018-05-01

The study deals with the features of the technique for simulating the capillary pressure curves of porous media on their X-ray microtomographic images. The results of a computational experiment on the immiscible displacement of an incompressible fluid by another in the pore space represented by a digital image of the Berea sandstone are presented. For the mathematical description of two-phase fluid flow we use Lattice Boltzmann Equation (LBM), and phenomena at the fluids interface are described by the color-gradient model. Compared with laboratory studies, the evaluation of capillary pressure based on the results of a computational filtration experiment is a non-destructive method and has a number of advantages: the absence of labor for preparation of fluids and core; the possibility of modeling on the scale of very small core fragments (several mm), which is difficult to realize under experimental conditions; three-dimensional visualization of the dynamics of filling the pore space with a displacing fluid during drainage and impregnation; the possibility of carrying out multivariate calculations for specified parameters of multiphase flow (density and viscosity of fluids, surface tension, wetting contact angle). A satisfactory agreement of the capillary pressure curves during drainage with experimental results was obtained. It is revealed that with the increase in the volume of the digital image, the relative deviation of the calculated and laboratory data decreases and for cubic digital cores larger than 1 mm it does not exceed 5%. The behavior of the non-wetting fluid flow during drainage is illustrated. It is shown that flow regimes under which computational and laboratory experiments are performed the distribution of the injected phase in directions different from the gradient of the hydrodynamic drop, including the opposite ones, is characteristic. Experimentally confirmed regularities are obtained when carrying out calculations for drainage and imbibition at different values of interfacial tension. There is a close coincidence in the average diameters of permeable channels, estimated by capillary curves for different interfacial tension and pore network model. The differences do not exceed 15%.

A proposed international watershed research network

USGS Publications Warehouse

Osterkamp, W.R.; Gray, J.R.

2003-01-01

An “International Watershed Research Network” is to be an initial project of the Sino-U. S. Centers for Soil and Water Conservation and Environmental Protection. The Network will provide a fundamental database for research personnel of the Centers, as well as of the global research community, and is viewed as an important resource for their successful operation. Efforts are under way to (a) identify and select candidate watersheds, (b) develop standards and protocols for data collection and dissemination, and (c) specify other data sources on erosion, sediment transport, hydrology, and ancillary information of probable interest and use to participants of the Centers. The initial focus of the Network will be on water-deficient areas. Candidate watersheds for the Network are yet to be determined although likely selections include the Ansai Research Station, northern China, and the Walnut Gulch Experimental Watershed, Arizona, USA. The Network is to be patterned after the Vigil Network, an open-ended group of global sites and small drainage basins for which Internet-accessible geomorphic, hydrologic, and biological data are periodically collected or updated. Some types of data, using similar instruments and observation methods, will be collected at all watersheds selected for the Network. Other data from the watersheds that may reflect individual watershed characteristics and research objectives will be collected as well.

Spaceborne imaging radar - Geologic and oceanographic applications

NASA Technical Reports Server (NTRS)

Elachi, C.

1980-01-01

Synoptic, large-area radar images of the earth's land and ocean surface, obtained from the Seasat orbiting spacecraft, show the potential for geologic mapping and for monitoring of ocean surface patterns. Structural and topographic features such as lineaments, anticlines, folds and domes, drainage patterns, stratification, and roughness units can be mapped. Ocean surface waves, internal waves, current boundaries, and large-scale eddies have been observed in numerous images taken by the Seasat imaging radar. This article gives an illustrated overview of these applications.

Final Environmental Assessment for Wildlife Control Actions at Williams Lake, Buckley Air Force Base, Colorado

DTIC Science & Technology

2012-06-01

Reservoir Quincy Reservoir A U R O R AD E N V E R 6th Avenue P eñ a B lv d. Denver International Airport Aurora Airport Centennial Airport N 0...of the Continental Divide. The Denver Basin is a structural depression that is 300 miles long and 200 miles wide and was formed about 67 million...hydrologic analysis: Basin contributing drainage area Width of the subwatershed Subwatershed slope Percent Imperviousness Depression storage

Installation Restoration Program. Remedial Investigation Report. Minnesota Air National Guard Base Duluth International Airport, Duluth, Minnesota. Volume 1

DTIC Science & Technology

1990-01-01

There are three above ground storage tanks for the storage of JP-4 jet fuel with ancillary piping, pumps, loading and unloading facilities, and...time daily basis. Workers are present to transfer jet fuel from delivery tncks to the storage tanks and from the storage tanks to fueling trucks...Ground-water flow and contaminant migration at Site 4, the fuel storage area, is generally toward the drainage ditch located immediately north of the

Performance of Subsurface Tube Drainage System in Saline Soils: A Case Study

NASA Astrophysics Data System (ADS)

Pali, A. K.

2015-06-01

In order to improve the saline and water logged soils caused due to groundwater table rise, installation of subsurface drainage system is considered as one of the best remedies. However, the design of the drainage system has to be accurate so that the field performance results conform to the designed results. In this investigation, the field performance of subsurface tube drainage system installed at the study area was evaluated. The performance was evaluated on the basis of comparison of the designed value of water table drop as 30 cm after 2 days of drainage and predicted and field measured hydraulic heads for a consecutive drainage period of 14 days. The investigation revealed that the actual drop of water table after 2 days of drainage was 25 cm, about 17 % less than the designed value of 30 cm after 2 days of drainage. The comparison of hydraulic heads predicted by Van Schilfgaarde equation of unsteady drainage with the field-measured hydraulic heads showed that the deviation of predicted hydraulic heads varied within a range of ±8 % indicating high acceptability of Van Schlifgaarde equation for designing subsurface drainage system in saline and water logged soils resembling to that of the study area.

Amylase, lipase, and volume of drainage fluid in gastrectomy for the early detection of complications caused by pancreatic leakage.

PubMed

Seo, Kyung Won; Yoon, Ki Young; Lee, Sang Ho; Shin, Yeon Myung; Choi, Kyung Hyun; Hwang, Hyun Yong

2011-12-01

Pancreatic leakage is a serious complication of gastrectomy due to stomach cancer. Therefore, we analyzed amylase and lipase concentrations in blood and drainage fluid, and evaluated the volume of drainage fluid to discern their usefulness as markers for the early detection of serious pancreatic leakage requiring reoperation after gastrectomy. From January 2001 to December 2007, we retrospectively analyzed data from 24,072 patient samples. We divided patients into two groups; 1) complications with pancreatic leakage (CG), and 2) no complications associated with pancreatic leakage (NCG). Values of amylase and lipase in the blood and drainage fluid, volume of the drainage fluid, and relationships among the volumes, amylase values, and lipase values in the drainage fluid were evaluated, respectively in the two groups. The mean amylase values of CG were significantly higher than those of NCG in blood and drainage fluid (P < 0.05). For lipase, statistically significant differences were observed in drainage fluid (P < 0.05). The mean volume (standard deviation) of the drained fluid through the tube between CG (n = 22) and NCG (n = 236) on postoperative day 1 were 368.41 (266.25) and 299.26 (300.28), respectively. There were no statistically significant differences between the groups (P = 0.298). There was a correlation between the amylase and lipase values in the drainage fluid (r = 0.812, P = 0.000). Among postoperative amylase and lipase values in blood and drainage fluid, and the volume of drainage fluid, the amylase in drainage fluid was better differentiated between CG and NCG than other markers. The volume of the drainage fluid did not differ significantly between groups.

Comparison of Suction Versus Nonsuction Drainage After Lung Resections: A Prospective Randomized Trial.

PubMed

Gocyk, Wojciech; Kużdżał, Jarosław; Włodarczyk, Janusz; Grochowski, Zbigniew; Gil, Tomasz; Warmus, Janusz; Kocoń, Piotr; Talar, Piotr; Obarski, Piotr; Trybalski, Łukasz

2016-10-01

Sufficiently large, prospective randomized trials comparing suction drainage and nonsuction drainage are lacking. The aim of the present study was to compare the effects of suction drainage and nonsuction drainage on the postoperative course in patients who have undergone lung resection. This prospective, randomized trial included patients undergoing different types of lung resections. On the day of surgery, suction drainage at -20 cm H2O was used. On the morning of the first postoperative day, patients, in whom the pulmonary parenchyma was fully reexpanded, were randomized in the ratio of 1:1. Patients assigned to group A continued with suction drainage, while those assigned to group B underwent nonsuction drainage. The study included 254 patients, with 127 patients in each group. The drainage volumes were 1098.8 mL and 814.4 mL in groups A and B, respectively (p = 0.0014). The times to chest tube removal were 5.61 days and 4.49 days in groups A and B, respectively (p = 0.0014). Prolonged air leakage occurred in 5.55% of patients in group A and in 0.7% of patients in group B (p = 0.032), and asymptomatic residual air spaces were noted in 0.8% of patients in group A and 9.4% of patients in group B (p = 0.0018). Nonsuction drainage is more effective than suction drainage with regard to drainage volume, drainage duration, and incidence of persistent air leakage. However, it is associated with a higher incidence of asymptomatic residual air spaces. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Effect of viscosity on tear drainage and ocular residence time.

PubMed

Zhu, Heng; Chauhan, Anuj

2008-08-01

An increase in residence time of dry eye medications including artificial tears will likely enhance therapeutic benefits. The drainage rates and the residence time of eye drops depend on the viscosity of the instilled fluids. However, a quantitative understanding of the dependence of drainage rates and the residence time on viscosity is lacking. The current study aims to develop a mathematical model for the drainage of Newtonian fluids and also for power-law non-Newtonian fluids of different viscosities. This study is an extension of our previous study on the mathematical model of tear drainage. The tear drainage model is modified to describe the drainage of Newtonian fluids with viscosities higher than the tear viscosity and power-law non-Newtonian fluids with rheological parameters obtained from fitting experimental data in literature. The drainage rate through canaliculi was derived from the modified drainage model and was incorporated into a tear mass balance to calculate the transients of total solute quantity in ocular fluids and the bioavailability of instilled drugs. For Newtonian fluids, increasing the viscosity does not affect the drainage rate unless the viscosity exceeds a critical value of about 4.4 cp. The viscosity has a maximum impact on drainage rate around a value of about 100 cp. The trends are similar for shear thinning power law fluids. The transients of total solute quantity, and the residence time agrees at least qualitatively with experimental studies. A mathematical model has been developed for the drainage of Newtonian fluids and power-law fluids through canaliculi. The model can quantitatively explain different experimental observations on the effect of viscosity on the residence of instilled fluids on the ocular surface. The current study is helpful for understanding the mechanism of fluid drainage from the ocular surface and for improving the design of dry eye treatments.

40 CFR 440.144 - New source performance standards (NSPS).

Code of Federal Regulations, 2011 CFR

2011-07-01

...-cut mine plant site shall not exceed the volume of infiltration, drainage and mine drainage waters... of infiltration, drainage and mine drainage waters which is in excess of the make up water required...

40 CFR 440.144 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

...-cut mine plant site shall not exceed the volume of infiltration, drainage and mine drainage waters... of infiltration, drainage and mine drainage waters which is in excess of the make up water required...

WTAQ - A computer program for aquifer-test analysis of confined and unconfined aquifers

USGS Publications Warehouse

Barlow, P.M.; Moench, A.F.

2004-01-01

Computer program WTAQ was developed to implement a Laplace-transform analytical solution for axial-symmetric flow to a partially penetrating, finite-diameter well in a homogeneous and anisotropic unconfined (water-table) aquifer. The solution accounts for wellbore storage and skin effects at the pumped well, delayed response at an observation well, and delayed or instantaneous drainage from the unsaturated zone. For the particular case of zero drainage from the unsaturated zone, the solution simplifies to that of axial-symmetric flow in a confined aquifer. WTAQ calculates theoretical time-drawdown curves for the pumped well and observation wells and piezometers. The theoretical curves are used with measured time-drawdown data to estimate hydraulic parameters of confined or unconfined aquifers by graphical type-curve methods or by automatic parameter-estimation methods. Parameters that can be estimated are horizontal and vertical hydraulic conductivity, specific storage, and specific yield. A sample application illustrates use of WTAQ for estimating hydraulic parameters of a hypothetical, unconfined aquifer by type-curve methods. Copyright ASCE 2004.

Drainage area data for Alabama streams

USGS Publications Warehouse

Stallings, J.S.; Peirce, L.B.

1957-01-01

The drainage area of a river basin is an important parameter in many engineering equations used for hydrologic design. It is not a parameter, however, that always requires precise measurement. Factors in the hydrologic cycle such as rainfall, runoff, transpiration, and infiltration cannot be measured nearly as closely as drainage area. Largely for this reason, drainage areas are often measured to varying degrees of precision depending upon the immediate need, with little thought to some other use or some other user of the figure obtained. It can readily be appreciated that this practice, continued for long by many different agencies, will result in a heterogeneous collection of drainage area figures, often discordant and of an accuracy unknown to any but those who computed them. Figures of drainage area published by various Federal agencies are frequently discrepant or contradictory, giving rise to confusion in the use of drainage area data. Seeking to better this situation, the Federal Inter-Agency River Basin Committee (FIARBC) in November 1951 published its Bulletin No. 4, Inter-Agency Coordination of Drainage Area Data. That Bulletin recommended procedures to be followed by the interested Federal agencies “for coordinating drainage area data in the interest of promoting uniformity, reducing confusion and contradiction of published figures, and improving the ready availability of drainage area data pertaining to drainage basins of the United States and its possessions.”

Pseudocyst in the Pancreatic Tail Associated with Chronic Pancreatitis Successfully Treated by Transpapillary Cyst Drainage

PubMed Central

Naitoh, Itaru; Ohara, Hirotaka; Okayama, Yasutaka; Nakazawa, Takahiro; Ando, Tomoaki; Hayashi, Kazuki; Okumura, Fumihiro; Kitajima, Yasuhiro; Ban, Tessin; Miyabe, Katsuyuki; Ueno, Koichiro; Joh, Takashi; Sano, Hitoshi

2008-01-01

We report a 50-year-old male with pseudocysts in the pancreatic tail associated with chronic pancreatitis successfully treated by transpapillary cyst drainage. He had previously undergone ultrasonography-guided percutaneous cyst drainage for a pancreatic pseudocyst in our hospital. He was readmitted due to abdominal pain and fever. Computed tomography showed recurrence of a pseudocyst in the pancreatic tail measuring 5 cm in diameter. Since conservative treatment failed, endoscopic retrograde pancreatography was performed. There was communication between the pseudocyst and the main pancreatic duct, and pancreatic duct stenosis proximal to the pseudocyst. First, transpapillary pancreatic duct drainage was performed using a plastic stent, but the pseudocyst did not decrease in size and became infected. After removal of the stent, a pigtail type nasocystic catheter was placed in the pseudocyst via the pancreatic duct. The pseudocyst infection immediately disappeared, and the pseudocyst gradually decreased and disappeared. After removal of the nasocystic catheter, no recurrence was observed. As transpapillary drainage of pancreatic pseudocyst, cyst drainage and pancreatic duct drainage have been reported. In our patient with pseudocyst in the pancreatic tail, duct drainage was ineffective and the pseudocyst was infected, whereas cyst drainage was very effective. We considered that cyst drainage by a nasocystic catheter was the first-line therapy as the transpapillary drainage of the pancreatic pseudocyst. PMID:21897788

Infectious arteritis of the internal carotid artery complicating retropharyngeal abscess.

PubMed

Lisan, Q; Tran, H; Verillaud, B; Herman, P

2016-02-01

Retropharyngeal abscess is a well-known entity in children, but can also occur in adults. The two main vascular complications are vascular compression and pseudoaneurysm, while infectious arteritis of the internal carotid artery is exceptional. The authors describe a case of a retropharyngeal abscess in an adult woman complicated by infectious arteritis of the internal carotid artery. This rare complication was treated by endovascular occlusion of the internal carotid artery and incision and drainage of the abscess in combination with antibiotic and anticoagulant therapy. The patient did not present any neurological sequelae and follow-up MRI did not reveal any signs of vascular or neurological complications. This case highlights the importance of thorough examination of imaging performed in the context of deep neck space abscess to detect signs of vascular involvement. Treatment must be aggressive in view of the life-threatening risk of arterial rupture or septic embolism. This is the first reported case of infectious arteritis involving the internal carotid artery complicating retropharyngeal abscess. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Intraventricular catheter placement by electromagnetic navigation safely applied in a paediatric major head injury patient.

PubMed

Aufdenblatten, Christoph Alexander; Altermatt, Stefan

2008-09-01

In the management of severe head injuries, the use of intraventricular catheters for intracranial pressure (ICP) monitoring and the option of cerebrospinal fluid drainage is gold standard. In children and adolescents, the insertion of a cannula in a compressed ventricle in case of elevated intracranial pressure is difficult; therefore, a pressure sensor is placed more often intraparenchymal as an alternative option. In cases of persistent elevated ICP despite maximal brain pressure management, the use of an intraventricular monitoring device with the possibility of cerebrospinal fluid drainage is favourable. We present the method of intracranial catheter placement by means of an electromagnetic navigation technique.