Acute hydrocephalus secondary to herpes simplex type II meningitis.

PubMed

Heppner, Peter A; Schweder, Patrick M; Monteith, Stephen J; Law, Andrew J J

2008-10-01

A 34-year-old woman presented with a rapid onset of meningitic symptoms. Cerebrospinal fluid (CSF) from a lumbar puncture revealed a leucocytosis with a preponderance of monocytes, elevated protein and reduced glucose. Herpes simplex virus (HSV) type II was subsequently confirmed by polymerase chain reaction (PCR) of CSF. The patient's level of consciousness deteriorated and a CT scan revealed hydrocephalus. The patient required placement of an external ventricular drain for 5 days; however, she made a full recovery without specific antiviral therapy. This is the first reported case of hydrocephalus secondary to isolated HSV type II meningitis.

External Ventricular Drain and Hemorrhage in Aneurysmal Subarachnoid Hemorrhage Patients on Dual Antiplatelet Therapy: A Retrospective Cohort Study.

PubMed

Hudson, Joseph S; Prout, Benjamin S; Nagahama, Yasunori; Nakagawa, Daichi; Guerrero, Waldo R; Zanaty, Mario; Chalouhi, Nohra; Jabbour, Pascal; Dandapat, Sudeepta; Allan, Lauren; Ortega-Gutierrez, Santiago; Samaniego, Edgar A; Hasan, David

2018-04-11

Stenting and flow diversion for aneurysmal sub arachnoid hemorrhage (aSAH) require the use of dual antiplatelet therapy (DAPT). To investigate whether DAPT is associated with hemorrhagic complication following placement of external ventricular drains (EVD) in patients with aSAH. Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who received DAPT for stenting or flow diversion, and patients who underwent microsurgical clipping or coiling and did not receive DAPT by way of a backward stepwise multivariate analysis. Four hundred forty-three patients were admitted for aSAH management. Two hundred ninety-eight patients required placement of an EVD. One hundred twenty patients (40%) were treated with stent-assisted coiling or flow diversion and required DAPT, while 178 patients (60%) were treated with coiling without stents or microsurgical clipping and did not receive DAPT. Forty-two (14%) cases of new hemorrhage along the EVD catheter were identified radiographically. Thirty-two of these hemorrhages occurred in patients on DAPT, while 10 occurred in patients without DAPT. After multivariate analysis, DAPT was significantly associated with radiographic hemorrhage [odds ratio: 4.92, 95% confidence interval: 2.45-9.91, P = .0001]. We did not observe an increased proportion of symptomatic hemorrhage in patients receiving DAPT (10 of 32 [31%]) vs those without (5 of 10 [50%]; P = .4508). Patients with aSAH who receive stent-assisted coiling or flow diversion are at higher risk for radiographic hemorrhage associated with EVD placement. The timing between EVD placement and DAPT initiation does not appear to be of clinical significance. Stenting and flow diversion remain viable options for aSAH patients.

Antibiotic Impregnated External Ventricular Drains: Meta and Cost Analysis.

PubMed

Root, Brandon K; Barrena, Benjamin G; Mackenzie, Todd A; Bauer, David F

2016-02-01

To determine whether antibiotic impregnated external ventricular drains (AI-EVDs) are effective in preventing ventriculostomy associated infection (VAI), and to examine their cost effectiveness. A comprehensive literature search was performed for published data through May 2014, including randomized controlled trials and observational cohort studies comparing AI-EVDs with nonimpregnated controls. A meta-analysis of included studies was performed using a random effects model. Historical data at the authors' institution were used to estimate both the incremental price of AI-EVDs and the hospital expenses associated with VAI. Three randomized controlled trials and 5 observational studies met inclusion criteria. The analysis demonstrated a statistically significant protective effect of AI-EVDs against VAI (risk ratio = 0.31 [0.15-0.64]; P = 0.002), although there was significant heterogeneity (χ(2) = 18.08; P = 0.01; I(2) = 61%). The number of AI-EVDs needed to prevent one infection (Number needed to treat [NNT]) was 19. Based on $100 as the incremental price, and $30,000 as the estimated expense of one episode of VAI, AI-EVDs would result in an overall savings estimate of $28,100 (range, $26,400-$28,500) per NNT. If a hospital places 150 AI-EVDs annually, savings could range from $109,292 to $278,577 per year. Meta-analysis demonstrated a significant protective benefit of AI-EVDs against VAI, and this benefit is likely associated with cost savings. However, current data on AI-EVDs are limited, and overall hospital costs will vary among institutions. Although both the efficacy and cost effectiveness of AI-EVDs are supported by this analysis, further study of AI-EVDs is clearly warranted. Copyright © 2016 Elsevier Inc. All rights reserved.

From the Skin to the Brain: Pathophysiology of Colonization and Infection of External Ventricular Drain, a Prospective Observational Study.

PubMed

Mounier, Roman; Lobo, David; Cook, Fabrice; Martin, Mathieu; Attias, Arie; Aït-Mamar, Bouziane; Gabriel, Inanna; Bekaert, Olivier; Bardon, Jean; Nebbad, Biba; Plaud, Benoît; Dhonneur, Gilles

2015-01-01

Ventriculostomy-related infection (VRI) is a serious complication of external ventricular drain (EVD) but its natural history is poorly studied. We prospectively tracked the bacteria pathways from skin towards ventricles to identify the infectious process resulting in ventriculostomy-related colonization (VRC), and VRI. We systematically sampled cerebrospinal fluid (CSF) on a daily basis and collected swabs from both the skin and stopcock every 3.0 days for microbiological analysis including in 101 neurosurgical patient. Risk factors for positive event defined as either VRC or VRI were recorded and related to our microbiological findings. A total of 1261 CSF samples, 473 skin swabs, and 450 stopcock swabs were collected. Skin site was more frequently colonized than stopcock (70 (60%) vs 34 (29%), p = 0.023), and earlier (14 ±1.4 vs 24 ±1.5 days, p<0.0001). Sixty-one (52%) and 32 (27%) skin and stopcock sites were colonized with commensal bacteria, 1 (1%) and 1 (1%) with pathogens, 8 (7%) and 1 (1%) with combined pathogens and commensal bacteria, respectively. Sixteen positive events were diagnosed; a cutaneous origin was identified in 69% of cases. The presence of a pathogen at skin site (6/16 vs 4/85, OR: 11.8, [2.5-56.8], p = 0.002) and CSF leakage (7/16 vs 6/85, OR 10 [2.4-41.2], p = 0.001)) were the two independent significant risk factors statistically linked to positive events occurrence. Our results suggest that VRC and VRI mainly results from an extra-luminal progression of pathogens initially colonizing the skin site where CSF leaks.

Accuracy and Safety of External Ventricular Drain Placement by Physician Assistants and Nurse Practitioners in Aneurysmal Acute Subarachnoid Hemorrhage.

PubMed

Enriquez-Marulanda, Alejandro; Ascanio, Luis C; Salem, Mohamed M; Maragkos, Georgios A; Jhun, Ray; Alturki, Abdulrahman Y; Moore, Justin M; Ogilvy, Christopher S; Thomas, Ajith J

2018-06-11

In the current dynamic health environment, increasing number of procedures are being completed by advanced practitioners (nurse practitioners and physician assistants). This is the first study to assess the clinical outcomes and safety of external ventricular drain (EVD) placements by specially trained advanced practitioners. Compare the safety and outcomes of EVD placement by advanced practitioners in patients with subarachnoid hemorrhage (SAH). A cohort comparison study was performed from an aneurysmal SAH database selecting patients treated with EVD from a single major academic institution in the USA between June 2007 and June 2017. Safety, accuracy, and complications of EVD placement were compared between advanced practitioners and neurosurgical physicians (attending neurosurgeon and subspecialty clinical fellow). Statistical analysis was performed using the Mann-Whitney test for continuous variables and χ 2 test for categorical variables, with p values set at < 0.05 for significance. We identified 203 patients for this cohort with 238 EVD placements; eighty-seven (36.6%) placements were performed by advanced practitioners and 151 (63.4%) by neurosurgeons. Most of the ventriculostomies were placed in the emergency room (n = 114; 47.9%). Additional procedures performed concurrently with the EVD placements were significantly higher among the physicians' group (21.8 vs. 4.6%; p < 0.001). Bedside placement and usage of Ghajar guide were significantly higher among advanced practitioner's (58.3 vs. 98.9 and 9.9 vs. 64.4%, respectively, with a p < 0.001 for both). There were, however, no significant differences in terms of the number of attempts for insertion, intraprocedural complications, tract hemorrhages, accuracy, infection rates, catheter dislodgments, and need for repositioning/replacement of EVD. After appropriate training, EVD placement can be safely performed by advanced practitioners with an adequate accuracy of placement.

From the Skin to the Brain: Pathophysiology of Colonization and Infection of External Ventricular Drain, a Prospective Observational Study

PubMed Central

Cook, Fabrice; Martin, Mathieu; Attias, Arie; Aït-Mamar, Bouziane; Gabriel, Inanna; Bekaert, Olivier; Bardon, Jean; Nebbad, Biba; Plaud, Benoît; Dhonneur, Gilles

2015-01-01

Ventriculostomy-related infection (VRI) is a serious complication of external ventricular drain (EVD) but its natural history is poorly studied. We prospectively tracked the bacteria pathways from skin towards ventricles to identify the infectious process resulting in ventriculostomy-related colonization (VRC), and VRI. We systematically sampled cerebrospinal fluid (CSF) on a daily basis and collected swabs from both the skin and stopcock every 3.0 days for microbiological analysis including in 101 neurosurgical patient. Risk factors for positive event defined as either VRC or VRI were recorded and related to our microbiological findings. A total of 1261 CSF samples, 473 skin swabs, and 450 stopcock swabs were collected. Skin site was more frequently colonized than stopcock (70 (60%) vs 34 (29%), p = 0.023), and earlier (14 ±1.4 vs 24 ±1.5 days, p<0.0001). Sixty-one (52%) and 32 (27%) skin and stopcock sites were colonized with commensal bacteria, 1 (1%) and 1 (1%) with pathogens, 8 (7%) and 1 (1%) with combined pathogens and commensal bacteria, respectively. Sixteen positive events were diagnosed; a cutaneous origin was identified in 69% of cases. The presence of a pathogen at skin site (6/16 vs 4/85, OR: 11.8, [2.5–56.8], p = 0.002) and CSF leakage (7/16 vs 6/85, OR 10 [2.4–41.2], p = 0.001)) were the two independent significant risk factors statistically linked to positive events occurrence. Our results suggest that VRC and VRI mainly results from an extra-luminal progression of pathogens initially colonizing the skin site where CSF leaks. PMID:26555597

Brain Trauma Foundation Guideline Compliance: Results of a Multidisciplinary, International Survey.

PubMed

Hirschi, Ryan; Rommel, Casey; Letsinger, Joshua; Nirula, Raminder; Hawryluk, Gregory W J

2018-05-09

Brain Trauma Foundation (BTF) guidelines reflect evidence-based best practices in management of traumatic brain injury. The aim of this study was to examine self-reported physician compliance and predictors of compliance related to BTF guidelines. We conducted an international, multidisciplinary survey examining self-reported adherence to BTF guidelines and multiple factors potentially affecting adherence. We also surveyed intracranial pressure monitoring practices. Of 154 physician respondents, 15.9% reported their institutions "always" follow BTF guidelines and 72.2% reported that they follow them "most of the time." Personal volume of traumatic brain injury cases and years in practice were not significantly related to adherence. Reported adherence varied significantly in association with respondent's institutional trauma level (P = 0.0010): 17.3% of practitioners at level I, 13.0% at level II, and 0% at level III trauma centers reported "always" following guidelines. Reported adherence to guidelines also varied significantly in association with provider specialty (P = 0.015) and institutional volume of severe traumatic brain injury cases (P = 0.008). Regarding intracranial pressure monitoring practices, 52% of respondents used external ventricular drains, 21% used intraparenchymal monitors, and 27% had no preference (P < 0.001). Of respondents not routinely using external ventricular drains, 36% claimed to "always" follow guidelines. There was no apparent association between type of intracranial pressure monitoring used and reported guideline adherence. Few respondents reported their institutions "always" follow BTF guidelines. General surgeons and providers at high-volume level I trauma centers were more likely to comply with guidelines. Differences in survey responses based on provider and institutional characteristics may help target educational efforts. Copyright © 2018 Elsevier Inc. All rights reserved.

Intracerebroventricular opiate infusion for refractory head and facial pain

PubMed Central

Lee, Darrin J; Gurkoff, Gene G; Goodarzi, Amir; Muizelaar, J Paul; Boggan, James E; Shahlaie, Kiarash

2014-01-01

AIM: To study the risks and benefits of intracerebroventricular (ICV) opiate pumps for the management of benign head and face pain. METHODS: SSix patients with refractory trigeminal neuralgia and/or cluster headaches were evaluated for implantation of an ICV opiate infusion pump using either ICV injections through an Ommaya reservoir or external ventricular drain. Four patients received morphine ICV pumps and two patientS received a hydromorphone pump. Of the Four patients with morphine ICV pumps, one patient had the medication changed to hydromorphone. Preoperative and post-operative visual analog scores (VAS) were obtained. Patients were evaluated post-operatively for a minimum of 3 mo and the pump dosage was adjusted at each outpatient clinic visit according to the patient’s pain level. RESULTS: All 6 patients had an intracerebroventricular opiate injection trial period, using either an Ommaya reservoir or an external ventricular drain. There was an average VAS improvement of 75.8%. During the trial period, no complications were observed. Pump implantation was performed an average of 3.7 wk (range 1-7) after the trial injections. After implantation, an average of 20.7 ± 8.3 dose adjustments were made over 3-56 mo after surgery to achieve maximal pain relief. At the most recent follow-up (26.2 mo, range 3-56), VAS scores significantly improved from an average of 7.8 ± 0.5 (range 6-10) to 2.8 ± 0.7 (range 0-5) at the final dose (mean improvement 5.0 ± 1.0, P < 0.001). All patients required a stepwise increase in opiate infusion rates to achieve maximal benefit. The most common complications were nausea and drowsiness, both of which resolved with pump adjustments. On average, infusion pumps were replaced every 4-5 years. CONCLUSION: These results suggest that ICV delivery of opiates may potentially be a viable treatment option for patients with intractable pain from trigeminal neuralgia or cluster headache. PMID:25133146

Delayed Retroclival and Cervical Spinal Subdural Hematoma Complicated by Preexisting Chiari Malformation in Adult Trauma Patient.

PubMed

Nguyen, Ha Son; Choi, Hoon; Kurpad, Shekar; Soliman, Hesham

2017-09-01

Traumatic spinal subdural hematoma involving the retroclival region and upper cervical spine is a rare pathology. To our knowledge, there have only been 2 prior cases in an adult trauma patient. We describe a patient with preexisting Chiari 1 malformation, who recently sustained a unilateral type 1 occipital condyle fracture with associated disruption of the tectorial membrane and transverse ligament, which returned with a retroclival subdural hematoma extending down to C7, causing spinal cord compression and symptomatic obstructive hydrocephalus. A 30-year-old female sustained a motor vehicle collision. Computed tomography C spine revealed a type I occipital condyle fracture. Magnetic resonance imaging C spine demonstrated disruption of the tectorial membrane and avulsion of the transverse ligament at its attachment to the left C1 tubercle; moreover, there was a Chiari 1 malformation. The patient was neurologically intact. A halo was recommended, but the patient opted for an aspen collar with close management. She was discharged but returned 3 days later with apneic episodes, along with bradycardia and hypertension. She was promptly intubated. Computed tomography head showed interval ventricular enlargement. Magnetic resonance imaging C spine revealed a new ventral hematoma spanning the retroclival region to C7, most pronounced at C2-C3. On examination, she opened her eyes to pain, her pupils were equal and reactive, and she withdrew in all extremities. An external ventricular drain was emergently placed. She underwent a suboccipital craniectomy, C1-3 laminectomies, and occiput-C4 instrumented fusion. The dura was significantly tense, and no epidural hematoma was observed during lateral exploration. Postoperatively, she woke up well, exhibiting a nonfocal neurologic examination. A diagnostic angiogram was negative. She was extubated uneventfully, and the external ventricular drain was weaned off in 4 days. Traumatic spinal subdural hematoma involving both the retroclival region and upper cervical spine can lead to bulbar signs and symptomatic obstructive hydrocephalus. There should be vigilance for this pathology in patients with high-energy craniocervical trauma. Disruption of the tectorial membrane and therapeutic anticoagulation may be risk factors. The clinical scenario can be complicated in the setting of a preexisting Chiari 1 malformation. Copyright © 2017 Elsevier Inc. All rights reserved.

Prophylactic antibiotics in pediatric shunt surgery.

PubMed

Biyani, N; Grisaru-Soen, G; Steinbok, P; Sgouros, S; Constantini, S

2006-11-01

The optimal antibiotic prophylaxis for pediatric shunt-related procedures is not clear. There is much inconsistency among different medical centers. This paper summarizes and analyzes the various prophylactic antibiotic regiments used for shunt-related surgeries at different pediatric neurosurgery centers in the world. A survey questionnaire was distributed through the Pediatric Neurosurgery list-server (an e-mail-based special interest group in pediatric neurosurgery). Forty-five completed questionnaires were received, one per medical center, primarily from pediatric neurosurgeons with the following geographic breakdown: 25 from North America, 13 from Europe, and 7 from Asia and other countries. All centers routinely administered prophylactic antibiotics for shunt-related procedures. The drugs of choice were first-generation cephalosporins (23), second-generation cephalosporins (10), naficillin/oxacillin (4), vancomycin (3), clindamycin (1), amoxicillin (1), and mixed protocols in three centers. The initial drug administration ("first dose") was: in the department before transfer to operating room (5), upon arrival to operating room (11), at induction of anesthesia (13), and at initial skin incision (16). The duration of antibiotic dosage also varied: single dose (13), 24-h administration (26), 48-h administration (2), and longer than 48 h in four centers. Two general tendencies were noted, common to the majority of participating centers. There was a general trend to modify antibiotic treatment protocol in "high-risk" populations. The second common theme noted in more than half of responding centers was the use of long-term antibiotic treatment for externalized devices (such as externalized shunts, external ventricular drains or lumbar drains), usually till the device was in place.

Negative-pressure and low-pressure hydrocephalus: the role of cerebrospinal fluid leaks resulting from surgical approaches to the cranial base.

PubMed

Filippidis, Aristotelis S; Kalani, M Yashar S; Nakaji, Peter; Rekate, Harold L

2011-11-01

Negative-pressure and low-pressure hydrocephalus are rare clinical entities that are frequently misdiagnosed. They are characterized by recurrent episodes of shunt failure because the intracranial pressure is lower than the opening pressure of the valve. In this report the authors discuss iatrogenic CSF leaks as a cause of low- or negative-pressure hydrocephalus after approaches to the cranial base. The authors retrospectively reviewed cases of low-pressure or negative-pressure hydrocephalus presenting after cranial approaches complicated with a CSF leak at their institution. Three patients were identified. Symptoms of high intracranial pressure and ventriculomegaly were present, although the measured pressures were low or negative. A blocked communication between the ventricles and the subarachnoid space was documented in 2 of the cases and presumed in the third. Shunt revisions failed repeatedly. In all cases, temporary clinical and radiographic improvement resulted from external ventricular drainage at subatmospheric pressures. The CSF leaks were sealed and CSF communication was reestablished operatively. In 1 case, neck wrapping was used with temporary success. Negative-pressure or low-pressure hydrocephalus associated with CSF leaks, especially after cranial base approaches, is difficult to treat. The solution often requires the utilization of subatmospheric external ventricular drains to establish a lower ventricular drainage pressure than the drainage pressure created in the subarachnoid space, where the pressure is artificially lowered by the CSF leak. Treatment involves correction of the CSF leak, neck wrapping to increase brain turgor and allow the pressure in the ventricles to rise to the level of the opening pressure of the valve, and reestablishing the CSF route.

Influence of the hole geometry on the flow distribution in ventricular catheters for hydrocephalus.

PubMed

Giménez, Ángel; Galarza, Marcelo; Pellicer, Olga; Valero, José; Amigó, José M

2016-07-15

Hydrocephalus is a medical condition consisting of an abnormal accumulation of cerebrospinal fluid within the brain. A catheter is inserted in one of the brain ventricles and then connected to an external valve to drain the excess of cerebrospinal fluid. The main drawback of this technique is that, over time, the ventricular catheter ends up getting blocked by the cells and macromolecules present in the cerebrospinal fluid. A crucial factor influencing this obstruction is a non-uniform flow pattern through the catheter, since it facilitates adhesion of suspended particles to the walls. In this paper we focus on the effects that tilted holes as well as conical holes have on the flow distribution and shear stress. We have carried out 3D computational simulations to study the effect of the hole geometry on the cerebrospinal fluid flow through ventricular catheters. All the simulations were done with the OpenFOAM® toolbox. In particular, three different groups of models were investigated by varying (i) the tilt angles of the holes, (ii) the inner and outer diameters of the holes, and (iii) the distances between the so-called hole segments. The replacement of cylindrical holes by conical holes was found to have a strong influence on the flow distribution and to lower slightly the shear stress. Tilted holes did not involve flow distribution changes when the hole segments are sufficiently separated, but the mean shear stress was certainly reduced. The authors present new results about the behavior of the fluid flow through ventricular catheters. These results complete earlier work on this topic by adding the influence of the hole geometry. The overall objective pursued by this research is to provide guidelines to improve existing commercially available ventricular catheters.

Ruptured Massa Intermedia Secondary to Hydrocephalus.

PubMed

El Damaty, Ahmed; Langner, Soenke; Schroeder, Henry W S

2017-01-01

We report a case of ruptured massa intermedia (MI) as a sequela of hydrocephalus. A single case report is presented describing the sequelae of tumor bed hematoma after a posterior fossa hemangioblastoma resection in which the patient bled 3 days after surgery, resulting in secondary hydrocephalus and subsequently dilatation of the third ventricle, which resulted in rupture of the MI. The patient was managed on emergency basis with an external ventricular drain then endoscopically with a third ventriculostomy and clot extraction. Absent MI is not uncommon in hydrocephalic patients, and it is assumed to be the result of rupture from acute dilatation of the third ventricle. Our case report proves this assumption and documents the presence and absence of the MI before and after developing hydrocephalus. Copyright © 2016 Elsevier Inc. All rights reserved.

Importance of the mitral apparatus for left ventricular function: an experimental approach.

PubMed

Gams, E; Hagl, S; Schad, H; Heimisch, W; Mendler, N; Sebening, F

1992-01-01

In an experimental study of 31 anesthetized dogs the importance of the mitral apparatus for the left ventricular function was investigated. During extracorporeal circulation bileaflet mitral valve prostheses were implanted preserving the mitral subvalvular apparatus. Flexible wires were slung around the chordae tendineae and exteriorized through the left ventricular wall to cut the chordae by electrocautery from the outside when the heart was beating again. External and internal left ventricular dimensions were measured by sonomicrometry, left ventricular stroke volume by electromagnetic flowmeters around the ascending aorta, left ventricular end-diastolic volume by dye dilution technique, and left ventricular pressure by catheter tip manometers. Different preload levels were achieved by volume loading with blood transfusion before and after cutting the chordae tendineae. When the chordae had been divided peak systolic left ventricular pressure did not change. Heart rate only increased at the lowest left ventricular end-diastolic pressures of 3-4 mmHg, but remained unchanged at higher preload levels. Cardiac output decreased significantly up to -9% at left ventricular end-diastolic pressures of 5-10 mmHg, while left ventricular dp/dtmax showed a consistent reduction of up to -15% at any preload level. Significant reductions were also seen in systolic shortening in the left ventricular major axis (by external measurements -27%, by internal recording -43%). Left ventricular end-diastolic dimensions increased in the major axis by +2% when recorded externally, by +10% when measured internally. Systolic and diastolic changes in the minor axis were not consistent and different in the external and internal recordings.(ABSTRACT TRUNCATED AT 250 WORDS)

Erroneous intracranial pressure measurements from simultaneous pressure monitoring and ventricular drainage catheters.

PubMed

Birch, A A; Eynon, C A; Schley, D

2006-01-01

The objective of this report is to highlight the potential for false pressure measurements from systems that combine intracranial pressure (ICP) measurement and ventricular drainage. If the ports of the drain become blocked to the extent that they present a high resistance to cerebrospinal fluid flow, then a significant pressure gradient between the inside and outside of the catheter may be established. Thus, any intracatheter transducer will faithfully record a pressure much lower than true ICP. This holds true for catheter-tip transducers when the transducer lies inside the catheter. In the absence of flow, however, pressures will equalize; therefore, accurate measurements may be taken if the drain is temporarily closed. We model this situation and provide simulations of expected measurements in such situations; these compare well to observed clinical readings.

[Wearable Automatic External Defibrillators].

PubMed

Luo, Huajie; Luo, Zhangyuan; Jin, Xun; Zhang, Leilei; Wang, Changjin; Zhang, Wenzan; Tu, Quan

2015-11-01

Defibrillation is the most effective method of treating ventricular fibrillation(VF), this paper introduces wearable automatic external defibrillators based on embedded system which includes EGG measurements, bioelectrical impedance measurement, discharge defibrillation module, which can automatic identify VF signal, biphasic exponential waveform defibrillation discharge. After verified by animal tests, the device can realize EGG acquisition and automatic identification. After identifying the ventricular fibrillation signal, it can automatic defibrillate to abort ventricular fibrillation and to realize the cardiac electrical cardioversion.

Externalized Conductor Cables in QuickSite Left Ventricular Pacing Lead and Riata Right Ventricular Lead in a Single Patient: A Common Problem With Silicone Insulation

PubMed Central

Lakshmanadoss, Umashankar; Hackett, Vera; Deshmukh, Pramod

2012-01-01

QuickSite (St Jude Medical, Sylmar, CA, USA) is a silicone and polyurethane-insulated coronary sinus pacing lead. Riata lead (St Jude Medical, Sylmar, CA, USA) is a silicone insulated right ventricular shock lead. Recently, insulation breach of silicone based leads raised a huge concern. Fluoroscopic examination of these two leads in the same patient revealed externalization of these two leads. Same mechanism producing insulation breach of Riata lead may be involved in externalization of QuickSite LV lead as distal part of insulation is also made of silicone. PMID:28348692

A randomized, placebo-controlled pilot study of patients with spontaneous intraventricular haemorrhage treated with intraventricular thrombolysis.

PubMed

King, Nicolas K K; Lai, Jin Li; Tan, Li Bing; Lee, Kah Keow; Pang, Boon Chuan; Ng, Ivan; Wang, Ernest

2012-07-01

Intraventricular hemorrhage (IVH) occurring after spontaneous intracerebral hemorrhage (ICH) is an independent risk factor for mortality. The use of intraventricular urokinase (Uk) to reduce intraventricular blood clot volume and improve outcome was investigated. Patients with IVH requiring external ventricular drainage were recruited and randomized into a double-blind placebo controlled study. Assessments of collected cerebrospinal fluid (CSF) haemoglobin (Hb) and serial CT scans were performed. The study outcomes were: infection rates, length of stay in the intensive care unit, survival, National Institutes of Health Stroke Scale score; and modified Rankin Scale scores. Our results showed an increase in both the drained CSF Hb concentration in patients treated with Uk compared to placebo and in the rate of resolution clot volume. No differences were found in the other outcome measures but there was a trend towards lowered mortality in the group treated with Uk. Therefore, intraventricular Uk resulted in faster resolution of IVH with no adverse events. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Research on automatic external defibrillator based on DSP].

PubMed

Jing, Jun; Ding, Jingyan; Zhang, Wei; Hong, Wenxue

2012-10-01

Electrical defibrillation is the most effective way to treat the ventricular tachycardia (VT) and ventricular fibrillation (VF). An automatic external defibrillator based on DSP is introduced in this paper. The whole design consists of the signal collection module, the microprocessor controlingl module, the display module, the defibrillation module and the automatic recognition algorithm for VF and non VF, etc. This automatic external defibrillator has achieved goals such as ECG signal real-time acquisition, ECG wave synchronous display, data delivering to U disk and automatic defibrillate when shockable rhythm appears, etc.

Following the canyon to reach and remove olfactory groove meningiomas.

PubMed

Stefini, Roberto; Zenga, Francesco; Giacomo, Esposito; Bolzoni, Andrea; Tartara, Fulvio; Spena, Giannantonio; Ambrosi, Claudia; Fontanella, Marco M

2017-04-01

Olfactory groove meningiomas (OGMs) represent approximately 10% of all intracranial meningiomas. They arise in the olfactory fossa, a variable depression delimited by the lateral lamella and perpendicular plate. The cribriform plate with the lateral lamella and ethmoidal and orbital roof could be viewed as a 'canyon' with the frontal sinus as the main entrance. Between January 2000 and December 2013, 32 consecutive patients underwent removal of OGMs through this 'canyon' at the Department of Neurosurgery of Brescia and Turin. Complete removal was achieved in all patients with this trans-frontal sinus subcranial approach (Simpson grade I; mean lesion volume, 46.6 cm3). Five patients (15.6%) experienced nasal CSF leakage, treated with external lumbar drain positioning for 4 days and resolved in all cases but one, which was re-operated. Two patients (6.2%) during the CSF leakage experienced meningitis at day 7 after surgery, both successfully treated by intravenous antibiotic therapy. After one month, one patient developed hydrocephalus, treated with a ventricular peritoneal shunt. In one patient, traction on the OGM caused bleeding of the callosomarginal artery, which was coagulated with superior frontal gyrus ischemia without neurological consequences. Glasgow Outcome Scale Score at 6 months was V in 29 patients, IV in one patient, and I in two patients. Advantages with this approach may include easy and early control of blood supply from its insertion in the skull base, minimal frontal lobe retraction, preservation of the frontal veins draining to the sagittal sinus, and a satisfactory aesthetic outcome.

A programmable point-of-care device for external CSF drainage and monitoring.

PubMed

Simkins, Jeffrey R; Subbian, Vignesh; Beyette, Fred R

2014-01-01

This paper presents a prototype of a programmable cerebrospinal fluid (CSF) external drainage system that can accurately measure the dispensed fluid volume. It is based on using a miniature spectrophotometer to collect color data to inform drain rate and pressure monitoring. The prototype was machined with 1 μm dimensional accuracy. The current device can reliably monitor the total accumulated fluid volume, the drain rate, the programmed pressure, and the pressure read from the sensor. Device requirements, fabrication processes, and preliminary results with an experimental set-up are also presented.

Continuous monitoring of intracranial pressure after endoscopic third ventriculostomy in the management of CSF shunt failure.

PubMed

Elgamal, E A

2010-04-01

The effectiveness of continuous intracranial pressure (ICP) monitoring in the adaptation period, after endoscopic third ventriculostomy (ETV), and removal of the failed shunt in the management of CSF shunt failure is assessed. Nine patients with active hydrocephalus presenting with CSF shunt obstruction or infection were managed by ETV, removal of the shunt and insertion of an external ventricular drain (EVD) containing an ICP sensor for the purpose of postoperative monitoring of the ICP, and intermittent drainage of CSF. Patient ages ranged from 8 months to 24 years, and six of them were females. Hydrocephalus was obstructive in seven patients, and multiloculated in two. Six patients had an ventriculoperitoneal shunt (VPS), one with a bilateral VPS, one patient had a ventriculoatrial shunt, and one had a VPS and cystoperitoneal shunt (CPS). Shunt failure was caused by obstruction in six patients and infection in three. The post-operative ICP monitoring period ranged from 1-7 days. Intracranial hypertension was persistent in the first day after ETV in 3 patients, and up to 110 mL of CSF were drained to improve its symptoms. ETV was successful in six patients and 3 had permanent VPS. Post-operative continuous ICP monitoring and EVD insertion were very useful in the treatment of CSF shunt failure with ETV. This procedure allowed intermittent CSF drainage, relieving symptoms of elevated ICP, and provided accurate assessment of the success of the ETV and patency of the stoma in the early postoperative days by CT ventriculography and can also be used to install antibiotics in cases of infection.

Surgical approach to left ventricular inflow obstruction due to dilated coronary sinus.

PubMed

Vargas, Florentino J; Rozenbaum, Jorge; Lopez, Ricardo; Granja, Miguel; De Dios, Ana; Zarlenga, Beatriz; Flores, Enrique; Fischman, Enrique; Kreutzer, Eduardo

2006-07-01

Left superior vena cava draining to a dilated coronary sinus can cause left ventricular inflow obstruction. Our purpose is to report 4 severely ill patients with this malformation who were operated upon and in whom repair was accomplished using an original surgical approach. An operative procedure was designed, which included complete resection of the wall of the coronary sinus along its entire extension in the left atrium; division of the left superior vena cava; and establishment of the left superior vena cava-right atrial continuity by a wide left superior vena cava-right atrial appendage anastomosis. The series included 1 patient with interrupted inferior vena cava-hemiazygous continuation to left superior vena cava. There were no deaths. Absence of residual left ventricular inflow obstruction was demonstrated at follow-up in all cases, together with an unobstructed left superior vena cava-right atrial appendage-right atrial connection. A predictable relief of the left ventricular inflow obstruction, together with preservation of an adequate drainage for the systemic venous return, were both achieved with this repair.

[Worldwide experience with automated external defibrillators: What have we achieved? What else can we expect?].

PubMed

Trappe, Hans-Joachim

2016-03-01

In Germany approximately 70,000-100,000 SCD patients die from sudden cardiac death (SCD). SCD is not caused by a single factor but is a multifactorial problem. In 50 % of SCD victims, sudden cardiac death is the first manifestation of heart disease. SCD is caused by ventricular tachyarrhythmias in approximately 90 % of patients, whereas SCD is caused by bradyarrhythmias in 5-10 % of the patients. Risk stratification is not possible in the majority of them prior to the fatal event. Early defibrillation is the method of choice to terminate ventricular fibrillation. Therefore, it is mandatory to install automatic external defibrillators (AED) in places with many people. There is general agreement that early defibrillation with automated external defibrillators (AED) is an effective tool to treat patients with ventricular fibrillation and will improve survival. It seems necessary to teach cardiocompression and AED use, also to children and adolescents. AED therapy "at home" did not improve survival in patients with cardiac arrest and can not be recommended.

Endovascular Treatment of Ruptured Vertebrobasilar Dissecting Aneurysms Using Flow Diversion Embolization Devices: Single-Institution Experience.

PubMed

Guerrero, Waldo R; Ortega-Gutierrez, Santiago; Hayakawa, Minako; Derdeyn, Colin P; Rossen, James D; Hasan, David; Samaniego, Edgar A

2018-01-01

Treatment of ruptured posterior circulation dissecting aneurysms is technically challenging with potentially high morbidity and mortality. We sought to assess the safety and feasibility of using a flow-diversion device (FDD) and a specific acute antiplatelet aggregation protocol in the management of ruptured dissecting aneurysms. Subjects with ruptured dissecting aneurysms treated during a 3-year period were retrospectively identified from a prospective registry. Intraoperative complications, morbidity, and mortality were recorded. Tirofiban maintenance infusion without bolus was administered intravenously immediately after deployment of the FDD, and almost all patients were loaded with dual antiplatelet (aspirin and clopidogrel) post procedure. Clinical follow-up evaluation and modified Rankin Scale were assessed. Nine subjects with ruptured posterior circulation dissecting aneurysms were treated with an FDD: 5 vertebral artery, 2 basilar artery, and 2 posterior inferior cerebellar artery aneurysms. Average World Federation of Neurosurgical Societies score was 2 (range 1-5). Seven patients had external ventricular drain placed acutely for hydrocephalus. Eight patients received tirofiban infusion without bolus after FDD. No intraoperative complications occurred. Two subjects developed asymptomatic intraparenchymal hemorrhage found on surveillance noncontrast computed tomography. One subject suffered a major intraparenchymal hemorrhage and died a few days post intervention after additional anticoagulation was started for a left ventricular assist device. Follow-up modified Rankin Scale within 12 months was 0 in 3 subjects, 1 in 3 subjects, 2 in 1 subject, and 4 in 1. Treatment of dissecting posterior circulation aneurysms with FDDs is feasible and a potential alternative to deconstructive techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

The Use of Automated External Defibrillators in Infants: A Report From the American Red Cross Scientific Advisory Council.

PubMed

Rossano, Joseph W; Jones, Wendell E; Lerakis, Stamatios; Millin, Michael G; Nemeth, Ira; Cassan, Pascal; Shook, Joan; Kennedy, Siobán; Markenson, David; Bradley, Richard N

2015-07-01

Automated external defibrillators (AEDs) have been used successfully in many populations to improve survival for out-of-hospital cardiac arrest. While ventricular fibrillation and pulseless ventricular tachycardia are more prevalent in adults, these arrhythmias do occur in infants. The Scientific Advisory Council of the American Red Cross reviewed the literature on the use of AEDs in infants in order to make recommendations on use in the population. The Cochrane library and PubMed were searched for studies that included AEDs in infants, any external defibrillation in infants, and simulation studies of algorithms used by AEDs on pediatric arrhythmias. There were 4 studies on the accuracy of AEDs in recognizing pediatric arrhythmias. Case reports (n = 2) demonstrated successful use of AED in infants, and a retrospective review (n = 1) of pediatric pads for AEDs included infants. Six studies addressed defibrillation dosages used. The algorithms used by AEDs had high sensitivity and specificity for pediatric arrhythmias and very rarely recommended a shock inappropriately. The energy doses delivered by AEDs were high, although in the range that have been used in out-of-hospital arrest. In addition, there are data to suggest that 2 to 4 J/kg may not be effective defibrillation doses for many children. In the absence of prompt defibrillation for ventricular fibrillation or pulseless ventricular tachycardia, survival is unlikely. Automated external defibrillators should be used in infants with suspected cardiac arrest, if a manual defibrillator with a trained rescuer is not immediately available. Automated external defibrillators that attenuate the energy dose (eg, via application of pediatric pads) are recommended for infants. If an AED with pediatric pads is not available, the AED with adult pads should be used.

[ILCOR recommendation on signage of automated external defibrillators (AEDs)].

PubMed

Truhlár, A

2010-05-01

Early defibrillation is a determinant of survival in both out-of-hospital and in-hospital cardiac arrests from ventricular fibrillation and pulseless ventricular tachycardia. The review summarizes importance of early defibrillation with automated external defibrillators (AED) and presents the International Liaison Committee on Resuscitation (ILCOR) recommendation for universal AED sign. The aim of the recommendation is to unify the AED signs worldwide and to spread the knowledge of this. The public in general, but healthcare professionals particularly, should be able to recognize AED location and use the device immediately in case of cardiac arrest.

The role of external drains and peritoneal conduits in the treatment of recurrent chronic subdural hematoma.

PubMed

Santarius, Thomas; Qureshi, Hammad U; Sivakumaran, Ram; Kirkpatrick, Peter J; Kirollos, Ramez W; Hutchinson, Peter J

2010-06-01

A considerable body of evidence supporting the use of external drainage after evacuation of primary chronic subdural hematoma (CSDH) exists in the literature. However, no systematic study of the value of postoperative drainage in the treatment of recurrent CSDH has been published. The aim of the study was to investigate external drains and subdural-to-peritoneal conduit in the treatment of recurrent CSDH. A retrospective review of cases of CSDH treated in our institution between October 2002 and October 2006 was conducted. During the study period, 408 patients had burr hole evacuation. Sixty-four patients (15.9%) had treatment for recurrence. One patient had craniotomy, and the remaining 63 had another burr hole evacuation: 36 without placement of a drain (BHO), 14 with external drainage (SED), and 13 with placement of subdural-peritoneal catheter (SPC). Fifteen patients (24%) developed a secondary recurrence requiring a third drainage procedure. Postoperative drainage (SED or SPC) was associated with a significantly lower secondary recurrence rate when compared to BHO: 3/27 (11%) versus 12/36 (33%) (χ(2), P=.040). There was no significant difference in recurrence rates between SED and SPC. Postoperative complications included acute subdural hematoma (2), subdural empyema (2), brain edema (2), pneumonia (3), and in-hospital death (2). None of the complications was associated with the use of a specific technique. The results indicate that, as in the treatment of primary CSDHs, the use of drain (SED or SPC) with burr hole evacuation is safe and is associated with lower recurrence rate. Further investigation is needed to clarify the indications of currently available surgical techniques in the treatment of recurrent CSDH. Copyright © 2010 Elsevier Inc. All rights reserved.

[Problems with placement and using of automated external defibrillators in Czech Republic].

PubMed

Olos, Tomás; Bursa, Filip; Gregor, Roman; Holes, David

2011-01-01

The use of automated external defibrillators improves the survival of adults who suffer from cardiopulmonary arrest. Automated external defibrillators detect ventricular fibrillation with almost perfect sensitivity and specificity. Authors describe the use of automated external defibrillator during cardiopulmonary resuscitation in a patient with sudden cardiac arrest during ice-hockey match. The article reports also the use of automated external defibrillators in children.

Smart Stylet: The development and use of a bedside external ventricular drain image-guidance system

PubMed Central

Patil, Vaibhav; Gupta, Rajiv; Estépar, Raúl San José; Lacson, Ronilda; Cheung, Arnold; Wong, Judith M.; Popp, A. John; Golby, Alexandra; Ogilvy, Christopher; Vosburgh, Kirby G.

2015-01-01

Background Placement accuracy of ventriculostomy catheters is reported in a wide and variable range. Development of an efficient image-guidance system may improve physician performance and patient safety. Objective We evaluate the prototype of Smart Stylet, a new electromagnetic image-guidance system for use during bedside ventriculostomy. Methods Accuracy of the Smart Stylet system was assessed. System operators were evaluated for their ability to successfully target the ipsilateral frontal horn in a phantom model. Results Target registration error across 15 intracranial targets ranged from 1.3 – 4.6 mm (mean 3.1 mm). Using Smart Stylet guidance, a test operator successfully passed a ventriculostomy catheter to a shifted ipsilateral frontal horn 20/20 (100%) times from the frontal approach in a skull phantom. Without Smart Stylet guidance, the operator was successful 4/10 (40 %) from the right frontal approach and 6/10 (60 %) from the left frontal approach. In a separate experiment, resident operators were successful 2/4 (50%) when targeting the shifted ipsilateral frontal horn with Smart Stylet guidance and 0/4 (0 %) without image-guidance using a skull phantom. Conclusions Smart Stylet may improve the ability to successfully target the ventricles during frontal ventriculostomy. PMID:25662506

Design optimization of the sensor spatial arrangement in a direct magnetic field-based localization system for medical applications.

PubMed

Marechal, Luc; Shaohui Foong; Zhenglong Sun; Wood, Kristin L

2015-08-01

Motivated by the need for developing a neuronavigation system to improve efficacy of intracranial surgical procedures, a localization system using passive magnetic fields for real-time monitoring of the insertion process of an external ventricular drain (EVD) catheter is conceived and developed. This system operates on the principle of measuring the static magnetic field of a magnetic marker using an array of magnetic sensors. An artificial neural network (ANN) is directly used for solving the inverse problem of magnetic dipole localization for improved efficiency and precision. As the accuracy of localization system is highly dependent on the sensor spatial location, an optimization framework, based on understanding and classification of experimental sensor characteristics as well as prior knowledge of the general trajectory of the localization pathway, for design of such sensing assemblies is described and investigated in this paper. Both optimized and non-optimized sensor configurations were experimentally evaluated and results show superior performance from the optimized configuration. While the approach presented here utilizes ventriculostomy as an illustrative platform, it can be extended to other medical applications that require localization inside the body.

Assessing residents' operative skills for external ventricular drain placement and shunt surgery in pediatric neurosurgery.

PubMed

Aldave, Guillermo; Hansen, Daniel; Briceño, Valentina; Luerssen, Thomas G; Jea, Andrew

2017-04-01

OBJECTIVE The authors previously demonstrated the use of a validated Objective Structured Assessment of Technical Skills (OSATS) tool for evaluating residents' operative skills in pediatric neurosurgery. However, no benchmarks have been established for specific pediatric procedures despite an increased need for meaningful assessments that can either allow for early intervention for underperforming trainees or allow for proficient residents to progress to conducting operations independently with more passive supervision. This validated methodology and tool for assessment of operative skills for common pediatric neurosurgical procedures-external ventricular drain (EVD) placement and shunt surgery- was applied to establish its procedure-based feasibility and reliability, and to document the effect of repetition on achieving surgical skill proficiency in pediatric EVD placement and shunt surgery. METHODS A procedure-based technical skills assessment for EVD placements and shunt surgeries in pediatric neurosurgery was established through the use of task analysis. The authors enrolled all residents from 3 training programs (Baylor College of Medicine, Houston Methodist Hospital, and University of Texas-Medical Branch) who rotated through pediatric neurosurgery at Texas Children's Hospital over a 26-month period. For each EVD placement or shunt procedure performed with a resident, the faculty and resident (for self-assessment) completed an evaluation form (OSATS) based on a 5-point Likert scale with 7 categories. Data forms were then grouped according to faculty versus resident (self) assessment, length of pediatric neurosurgery rotation, postgraduate year level, and date of evaluation ("beginning of rotation," within 1 month of start date; "end of rotation," within 1 month of completion date; or "middle of rotation"). Descriptive statistical analyses were performed with the commercially available SPSS statistical software package. A p value < 0.05 was considered statistically significant. RESULTS Five attending evaluators (including 2 fellows who acted as attending surgeons) completed 260 evaluations. Twenty house staff completed 269 evaluations for self-assessment. Evaluations were completed in 562 EVD and shunt procedures before the surgeons left the operating room. There were statistically significant differences (p < 0.05) between overall attending (mean 4.3) and junior resident (self; mean 3.6) assessments, and between overall attending (mean 4.8) and senior resident (self; mean 4.6) assessment scores on general performance and technical skills. The learning curves produced for the residents demonstrate a stereotypical U- or V-shaped curve for acquiring skills, with a significant improvement in overall scores at the end of the rotation compared with the beginning. The improvement for junior residents (Δ score = 0.5; p = 0.002) was larger than for senior residents (Δ score = 0.2; p = 0.018). CONCLUSIONS The OSATS is an effective assessment tool as part of a comprehensive evaluation of neurosurgery residents' performance for specific pediatric procedures. The authors observed a U-shaped learning curve, contradicting the idea that developing one's surgical technique and learning a procedure represents a monotonic, cumulative process of repetitions and improvement.

Wide localized solutions of the parity-time-symmetric nonautonomous nonlinear Schrödinger equation

NASA Astrophysics Data System (ADS)

Meza, L. E. Arroyo; Dutra, A. de Souza; Hott, M. B.; Roy, P.

2015-01-01

By using canonical transformations we obtain localized (in space) exact solutions of the nonlinear Schrödinger equation (NLSE) with cubic and quintic space and time modulated nonlinearities and in the presence of time-dependent and inhomogeneous external potentials and amplification or absorption (source or drain) coefficients. We obtain a class of wide localized exact solutions of NLSE in the presence of a number of non-Hermitian parity-time (PT )-symmetric external potentials, which are constituted by a mixing of external potentials and source or drain terms. The exact solutions found here can be applied to theoretical studies of ultrashort pulse propagation in optical fibers with focusing and defocusing nonlinearities. We show that, even in the presence of gain or loss terms, stable solutions can be found and that the PT symmetry is an important feature to guarantee the conservation of the average energy of the system.

The health workforce crisis: the brain drain scourge.

PubMed

Ike, Samuel O

2007-01-01

The magnitude of the health workforce crisis engendered by brain drain particularly in Africa, and nay more especially Nigeria, has been assuming increasingly alarming proportions in the past three decades. The challenge it poses in meeting the manpower needs in the healthcare sector as well as in the larger economy of the sending countries is enormous. This paper thus sets out to highlight the scope of this brain drain, its effects and the reasons sustaining it, as well as makes concrete suggestions to help stern the tide. A review of the literature on brain drain with particular emphasis on the health workforce sector was done, with focus on Africa, and specifically Nigeria. Literature search was done using mainly the Medline, as well as local journals. The historical perspectives, with the scope of external and internal brain drain are explored. The glaring effects of brain drain both in the global workforce terrain and specifically in the health sectors are portrayed. The countries affected most and the reasons for brain drain are outlined. Strategic steps to redress the brain drain crisis are proffered in this paper. The health workforce crisis resulting from brain drain must be brought to the front-burner of strategic policy decisions leading to paradigm shift in political, social and economic conditions that would serve as incentives to curb the scourge.

Chronic Heart Failure: Contemporary Diagnosis and Management

PubMed Central

Ramani, Gautam V.; Uber, Patricia A.; Mehra, Mandeep R.

2010-01-01

Chronic heart failure (CHF) remains the only cardiovascular disease with an increasing hospitalization burden and an ongoing drain on health care expenditures. The prevalence of CHF increases with advancing life span, with diastolic heart failure predominating in the elderly population. Primary prevention of coronary artery disease and risk factor management via aggressive blood pressure control are central in preventing new occurrences of left ventricular dysfunction. Optimal therapy for CHF involves identification and correction of potentially reversible precipitants, target-dose titration of medical therapy, and management of hospitalizations for decompensation. The etiological phenotype, absolute decrease in left ventricular ejection fraction and a widening of QRS duration on electrocardiography, is commonly used to identify patients at increased risk of progression of heart failure and sudden death who may benefit from prophylactic implantable cardioverter-defibrillator placement with or without cardiac resynchronization therapy. Patients who transition to advanced stages of disease despite optimal traditional medical and device therapy may be candidates for hemodynamically directed approaches such as a left ventricular assist device; in selected cases, listing for cardiac transplant may be warranted. PMID:20118395

Implantation of a cardiac resynchronization therapy-defibrillator device in a patient with persistent left superior vena cava.

PubMed

Atar, İlyas; Karaçağlar, Emir; Özçalık, Emre; Özin, Bülent; Müderrisoğlu, Haldun

2015-06-01

Presence of a persistent left superior vena cava (PLSVC) is generally clinically asymptomatic and discovered incidentally during central venous catheterization. However, PLSVC may cause technical difficulties during cardiac device implantation. An 82-year-old man with heart failure symptoms and an ejection fraction (EF) of 20% was scheduled for resynchronization therapy-defibrillator device (CRT-D) implantation. A PLSVC draining via a dilated coronary sinus into an enlarged right atrium was diagnosed. First, an active-fixation right ventricular lead was inserted into the right atrium through the PLSVC. The stylet was preshaped to facilitate its passage to the right ventricular apex. An atrial lead was positioned on the right atrium free wall, and an over-the-wire coronary sinus lead deployed to a stable position. CRT-D implantation procedure was successfully completed.

Experiments of draining and filling processes in a collapsible tube at high external pressure

NASA Astrophysics Data System (ADS)

Flaud, P.; Guesdon, P.; Fullana, J.-M.

2012-02-01

The venous circulation in the lower limb is mainly controlled by the muscular action of the calf. To study the mechanisms governing the venous draining and filling process in such a situation, an experimental setup, composed by a collapsible tube under external pressure, has been built. A valve preventing back flows is inserted at the bottom of the tube and allows to model two different configurations: physiological when the fluid flow is uni-directional and pathological when the fluid flows in both directions. Pressure and flow rate measurements are carried out at the inlet and outlet of the tube and an original optical device with three cameras is proposed to measure the instantaneous cross-sectional area. The experimental results (draining and filling with physiological or pathological valves) are confronted to a simple one-dimensional numerical model which completes the physical interpretation. One major observation is that the muscular contraction induces a fast emptying phase followed by a slow one controlled by viscous effects, and that a defect of the valve decreases, as expected, the ejected volume.

Prediction of the external work of the native heart from the dynamic H-Q curves of the rotary blood pumps during left heart bypass.

PubMed

Yokoyama, Yoshimasa; Kawaguchi, Osamu; Kitao, Takashi; Kimura, Taro; Steinseifer, Ulrich; Takatani, Setsuo

2010-09-01

The ventricular performance is dependent on the drainage effect of rotary blood pumps (RBPs) and the performance of RBPs is affected by the ventricular pulsation. In this study, the interaction between the ventricle and RBPs was examined using the pressure-volume (P-V) diagram of the ventricle and dynamic head pressure-bypass flow (H-Q) curves (H, head pressure: arterial pressure minus ventricular pressure vs. Q, bypass flow) of the RBPs. We first investigated the relationships in a mock loop with a passive fill ventricle, followed by validation in ex vivo animal experiments. An apical drainage cannula with a micro-pressure sensor was especially fabricated to obtain ventricular pressure, while three pairs of ultrasonic crystals placed on the heart wall were used to derive ventricular volume. The mock loop-configured ventricular apical-descending aorta bypass revealed that the external work of the ventricle expressed by the area inside the P-V diagrams (EW(Heart) ) correlated strongly with the area inside dynamic H-Q curves (EW(VAD)), with the coefficients of correlation being R² = 0.869 ∼ 0.961. The results in the mock loop were verified in the ex vivo studies using three Shiba goats (10-25 kg in body weight), showing the correlation coefficients of R² = 0.802 ∼ 0.817. The linear regression analysis indicated that the increase in the bypass flow reduced pulsatility in the ventricle expressed in EW(Heart) as well as in EW(VAD) . Experimental results, both mock loop and animal studies, showed that the interaction between cardiac external work and H-Q performance of RBPs can be expressed by the relationships "EW(Heart) versus EW(VAD) ." The pulsatile nature of the native heart can be expressed in the area underneath the H-Q curves of RBPs EW(VAD) during left heart bypass indicating the status of the level of assistance by RBPs and the native heart function. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Massive pediatric neurosurgical injuries and lessons learned following a tornado disaster in Alabama.

PubMed

Chern, Joshua J; Miller, Joseph H; Tubbs, R Shane; Whisenhunt, Thomas R; Johnston, James M; Wellons, John C; Rozzelle, Curtis J; Blount, Jeffrey P; Oakes, W Jerry

2011-12-01

A large volume of patients presented to a Level I pediatric trauma center during and after a recent tornado disaster. Injuries of the central and peripheral nervous systems and the medical responses of a pediatric neurosurgical team are reviewed. The clinical courses of patients who suffered cranial, spinal, and peripheral nerve injuries due to the tornado storm are reported. The clinical actions taken by the neurosurgical team during and after the event are reviewed and the lessons learned are discussed. The tornado storm system moved through the Tuscaloosa and Birmingham metropolitan areas on the early evening hours of April 27, 2011. Twenty-four patients received care from the neurosurgical team. A total of 11 cranial (including placement of an external ventricular drain), 2 spine, and 2 peripheral procedures were performed for the victims. Nine procedures were performed within the first 12 hours of the event, and an additional 6 surgeries were performed in the following 24 hours. Injuries of the peripheral nervous system often presented in a delayed fashion. Several key components were identified that enabled adequate neurosurgical care for a large influx of acute patients. Massive casualties due to tornados are rare. A well-organized physician team working with the hospital administration may decrease the mortality and morbidity of such events.

Transcranial Evacuation of Atypical Progressive Supradiaphragmatic Hematoma After Transsphenoidal Complete Resection of Pituitary Adenoma.

PubMed

Metwali, Hussam; Fahlbusch, Rudolf

2017-06-01

Supradiaphragmatic hematoma is a type of hematoma that occurs after transsphenoidal (TS) resection of pituitary adenoma and requires special management. Two patients had symptomatic supradiaphragmatic hematomas after total TS resection of pituitary adenomas in the absence of vascular anomalies. Both patients also had hydrocephalus at the time of diagnosis of the hematoma. The initial endoscopic endonasal inspection showed no subdiaphragmatic bleeding. The hematoma was evacuated via a frontolateral approach after insertion of an external ventricular drain (EVD). The supradiaphragmatic hematoma could be clinically and radiologically distinguished. It presented early with visual deterioration without headache. The patients developed hydrocephalus, which was associated with deterioration of level of consciousness. Radiologically, the hematoma filled the suprasellar space and was associated with the extension of bleeding in the basal cisterns. Recovery was good in both patients. There were no permanent neurologic deficits. The EVD was removed in both patients. One patient required a ventriculoperitoneal shunt because of delayed hydrocephalus. Supradiaphragmatic hematoma can be clinically and radiologically distinguished from other types of hematoma occurring after TS resection of pituitary adenoma. Transcranial surgery should be performed to manage supradiaphragmatic hematoma, when symptomatic. Insertion of an EVD at the time of evacuation is mandatory to relax the brain and to alleviate the hydrocephalus. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulation of acute haemodynamic outcomes of the surgical strategies for the right ventricular failure treatment in pediatric LVAD.

PubMed

Di Molfetta, Arianna; Ferrari, Gianfranco; Iacobelli, Roberta; Filippelli, Sergio; Fresiello, Libera; Gagliardi, Maria G; Toscano, Alessandro; Trivella, Maria G; Amodeo, Antonio

2015-12-01

Right ventricular failure (RVF) is one of the major complications during LVAD. Apart from drug therapy, the most reliable option is the implantation of RVAD. However, BIVAD have a poor prognosis and increased complications. Experiments have been conducted on alternative approaches, such as the creation of an atrial septal defect (ASD), a cavo-aortic shunt (CAS) including the LVAD and a cavo-pulmonary connection (CPC). This work aims at realizing a lumped parameter model (LPM) to compare the acute hemodynamic effects of ASD, CPC, CAS, RVAD in LVAD pediatric patients with RVF. Data of 5 pediatric patients undergoing LVAD were retrospectively collected to reproduce patients baseline hemodynamics with the LPM. The effects of continuous flow LVAD implantation complicated by RVF was simulated and then the effects of ASD, CPC, CAS and RVAD treatments were simulated for each patient. The model successfully reproduced patients' baseline and the hemodynamic effects of the surgical strategies. Simulating the different surgical strategies, an unloading of the right ventricle and an increment of left ventricular preload were observed with an improvement of the hemodynamics (total cardiac output: ASD +15%, CPC +10%, CAS +70% RVAD +20%; right ventricular external work: ASD -19%, CPC -46%, CAS -76%, RVAD -32%; left ventricular external work: ASD +12%, CPC +28%, RVAD +64%). The use of numerical model could offer an additional support for clinical decision-making, also potentially reducing animal experiments, to compare the outcome of different surgical strategies to treat RVF in LVAD.

Outflow monitoring of a pneumatic ventricular assist device using external pressure sensors.

PubMed

Kang, Seong Min; Her, Keun; Choi, Seong Wook

2016-08-25

In this study, a new algorithm was developed for estimating the pump outflow of a pneumatic ventricular assist device (p-VAD). The pump outflow estimation algorithm was derived from the ideal gas equation and determined the change in blood-sac volume of a p-VAD using two external pressure sensors. Based on in vitro experiments, the algorithm was revised to consider the effects of structural compliance caused by volume changes in an implanted unit, an air driveline, and the pressure difference between the sensors and the implanted unit. In animal experiments, p-VADs were connected to the left ventricles and the descending aorta of three calves (70-100 kg). Their outflows were estimated using the new algorithm and compared to the results obtained using an ultrasonic blood flow meter (UBF) (TS-410, Transonic Systems Inc., Ithaca, NY, USA). The estimated and measured values had a Pearson's correlation coefficient of 0.864. The pressure sensors were installed at the external controller and connected to the air driveline on the same side as the external actuator, which made the sensors easy to manage.

Multiple left anterior descending coronary artery to left ventricular fistula - A case series and literature review.

PubMed

Iyer, Praneet; Yelisetti, Rishitha

2017-10-01

Coronary artery fistulas (CAFs) are found in 0.3-0.8% of patients who undergo coronary angiography. CAFs are defined as single or multiple, small or large direct communications that arise from one or more coronary arteries and enter into one of the four cardiac chambers or major vessels. We present two cases of multiple coronary artery fistulas arising from diagonal and left anterior descending (LAD) branches of left coronary artery draining into the left ventricle. In both the cases, No intervention was performed. Of the congenital fistulas, two major groups are identified: solitary CAFs or coronary artery-left ventricular multiple micro-fistulas (CALVMMFs). Noninvasive techniques such as transthoracic echocardiography, transesophageal echocardiography and magnetic resonance imaging are becoming increasingly popular for diagnosis and follow-up of CAFs. Despite the advent of these newer non-invasive modalities, coronary angiography remains the gold standard for diagnosis. Treatment of CAFs is indicated when the patients are symptomatic with left ventricular volume overload, myocardial ischemia, left ventricular dysfunction or in the presence of a large or increasing left-to-right shunt. If the fistula is small and hemodynamically insignificant, it can be managed with conservative management. Multiple left anterior descending to left ventricle (LV) fistulas are extremely rare and, as per our literature review, we noted only a few case reports of coronary artery fistulas between branches of LAD and left ventricle.

Transmural recording of shock potential gradient fields, early postshock activations, and refibrillation episodes associated with external defibrillation of long-duration ventricular fibrillation in swine.

PubMed

Allred, James D; Killingsworth, Cheryl R; Allison, J Scott; Dosdall, Derek J; Melnick, Sharon B; Smith, William M; Ideker, Raymond E; Walcott, Gregory P

2008-11-01

Knowledge of the shock potential gradient (nablaV) and postshock activation is limited to internal defibrillation of short-duration ventricular fibrillation (SDVF). The purpose of this study was to determine these variables after external defibrillation of long-duration VF (LDVF). In six pigs, 115-20 plunge needles with three to six electrodes each were inserted to record throughout both ventricles. After the chest was closed, the biphasic defibrillation threshold (DFT) was determined after 20 seconds of SDVF with external defibrillation pads. After 7 minutes of LDVF, defibrillation shocks that were less than or equal to the SDVF DFT strength were given. For DFT shocks (1632 +/- 429 V), the maximum minus minimum ventricular voltage (160 +/- 100 V) was 9.8% of the shock voltage. Maximum cardiac nablaV (28.7 +/- 17 V/cm) was 4.7 +/- 2.0 times the minimum nablaV (6.2 +/- 3.5 V/cm). Although LDVF did not increase the DFT in five of the six pigs, it significantly lengthened the time to earliest postshock activation following defibrillation (1.6 +/- 2.2 seconds for SDVF and 4.9 +/- 4.3 seconds for LDVF). After LDVF, 1.3 +/- 0.8 episodes of spontaneous refibrillation occurred per animal, but there was no refibrillation after SDVF. Compared with previous studies of internal defibrillation, during external defibrillation much less of the shock voltage appears across the heart and the shock field is much more even; however, the minimum nablaV is similar. Compared with external defibrillation of SDVF, the biphasic external DFT for LDVF is not increased; however, time to earliest postshock activation triples. Refibrillation is common after LDVF but not after SDVF in these normal hearts, indicating that LDVF by itself can cause refibrillation without requiring preexisting heart disease.

Ventricular fibrillation

MedlinePlus

... arrives. VF is treated by delivering a quick electric shock through the chest. It is done using a device called an external defibrillator. The electric shock can immediately restore the heartbeat to a ...

Vernakalant selectively prolongs atrial refractoriness with no effect on ventricular refractoriness or defibrillation threshold in pigs.

PubMed

Bechard, Jeff; Gibson, John Ken; Killingsworth, Cheryl R; Wheeler, Jeffery J; Schneidkraut, Marlowe J; Huang, Jian; Ideker, Raymond E; McAfee, Donald A

2011-03-01

Vernakalant is a novel antiarrhythmic agent that has demonstrated clinical efficacy for the treatment of atrial fibrillation. Vernakalant blocks, to various degrees, cardiac sodium and potassium channels with a pattern that suggests atrial selectivity. We hypothesized, therefore, that vernakalant would affect atrial more than ventricular effective refractory period (ERP) and have little or no effect on ventricular defibrillation threshold (DFT). Atrial and ventricular ERP and ventricular DFT were determined before and after treatment with vernakalant or vehicle in 23 anesthetized male mixed-breed pigs. Vernakalant was infused at a rate designed to achieve stable plasma levels similar to those in human clinical trials. Atrial and ventricular ERP were determined by endocardial extrastimuli delivered to the right atria or right ventricle. Defibrillation was achieved using external biphasic shocks delivered through adhesive defibrillation patches placed on the thorax after 10 seconds of electrically induced ventricular fibrillation. The DFT was estimated using the Dixon "up-and-down" method. Vernakalant significantly increased atrial ERP compared with vehicle controls (34 ± 8 versus 9 ± 7 msec, respectively) without significantly affecting ventricular ERP or DFT. This is consistent with atrial selective actions and supports the conclusion that vernakalant does not alter the efficacy of electrical defibrillation.

Prevalence and prognosis of ventricular tachycardia/ventricular fibrillation in patients with post-infarction left ventricular aneurysm: Analysis of 575 cases.

PubMed

Ning, Xiaohui; Ye, Xuerui; Si, Yanhua; Yang, Zihe; Zhao, Yunzi; Sun, Qi; Chen, Ruohan; Tang, Min; Chen, Keping; Zhang, Xiaoli; Zhang, Shu

2018-03-21

We investigated the prevalence of ventricular tachycardia/ventricular fibrillation (VT/VF) in Post-infarction left ventricular aneurysm (PI-LVA) patients and analyze clinical outcomes in patients presenting with VT/VF. 575 PI-LVA patients were enrolled and investigated by logistic regression analysis. Patients with VT/VF were followed up, the composite primary endpoint was cardiac death and appropriate ICD/external shocks. The incidence of sustained VT/VF was 11%. Logistical regression analysis showed male gender, enlarged LV end diastolic diameter (LVEDD) and higher NYHA class were correlated with VT/VF development. During follow up of 46 ± 15 months, 19 out of 62(31%) patients reached study end point. Multivariate Cox regression analysis revealed that enlarged LVEDD and moderate/severe mitral regurgitation (MR) were independently predictive of clinical outcome. Male gender, enlarged LVEDD and higher NYHA class associated with risk of sustained VT/VF in PI-LVA patients. Among VT/VF positive patients, enlarged LVEDD and moderate/severe MR independently predicted poor clinical prognosis. Copyright © 2018. Published by Elsevier Inc.

Ventricular Fibrillation

MedlinePlus

... heart with a device called an automated external defibrillator (AED). Treatments to prevent sudden cardiac death for ... can even be purchased for your home. Portable defibrillators come with built-in instructions for their use. ...

Brain drain and health workforce distortions in Mozambique.

PubMed

Sherr, Kenneth; Mussa, Antonio; Chilundo, Baltazar; Gimbel, Sarah; Pfeiffer, James; Hagopian, Amy; Gloyd, Stephen

2012-01-01

Trained human resources are fundamental for well-functioning health systems, and the lack of health workers undermines public sector capacity to meet population health needs. While external brain drain from low and middle-income countries is well described, there is little understanding of the degree of internal brain drain, and how increases in health sector funding through global health initiatives may contribute to the outflow of health workers from the public sector to donor agencies, non-governmental organisations (NGOs), and the private sector. An observational study was conducted to estimate the degree of internal and external brain drain among Mozambican nationals qualifying from domestic and foreign medical schools between 1980-2006. Data were collected 26-months apart in 2008 and 2010, and included current employment status, employer, geographic location of employment, and main work duties. Of 723 qualifying physicians between 1980-2006, 95.9% (693) were working full-time, including 71.1% (493) as clinicians, 20.5% (142) as health system managers, and 6.9% (48) as researchers/professors. 25.5% (181) of the sample had left the public sector, of which 62.4% (113) continued working in-country and 37.6% (68) emigrated from Mozambique. Of those cases of internal migration, 66.4% (75) worked for NGOs, 21.2% (24) for donor agencies, and 12.4% (14) in the private sector. Annual incidence of physician migration was estimated to be 3.7%, predominately to work in the growing NGO sector. An estimated 36.3% (41/113) of internal migration cases had previously held senior-level management positions in the public sector. Internal migration is an important contributor to capital flight from the public sector, accounting for more cases of physician loss than external migration in Mozambique. Given the urgent need to strengthen public sector health systems, frank reflection by donors and NGOs is needed to assess how hiring practices may undermine the very systems they seek to strengthen.

Brain Drain and Health Workforce Distortions in Mozambique

PubMed Central

Sherr, Kenneth; Mussa, Antonio; Chilundo, Baltazar; Gimbel, Sarah; Pfeiffer, James; Hagopian, Amy; Gloyd, Stephen

2012-01-01

Introduction Trained human resources are fundamental for well-functioning health systems, and the lack of health workers undermines public sector capacity to meet population health needs. While external brain drain from low and middle-income countries is well described, there is little understanding of the degree of internal brain drain, and how increases in health sector funding through global health initiatives may contribute to the outflow of health workers from the public sector to donor agencies, non-governmental organisations (NGOs), and the private sector. Methods An observational study was conducted to estimate the degree of internal and external brain drain among Mozambican nationals qualifying from domestic and foreign medical schools between 1980–2006. Data were collected 26-months apart in 2008 and 2010, and included current employment status, employer, geographic location of employment, and main work duties. Results Of 723 qualifying physicians between 1980–2006, 95.9% (693) were working full-time, including 71.1% (493) as clinicians, 20.5% (142) as health system managers, and 6.9% (48) as researchers/professors. 25.5% (181) of the sample had left the public sector, of which 62.4% (113) continued working in-country and 37.6% (68) emigrated from Mozambique. Of those cases of internal migration, 66.4% (75) worked for NGOs, 21.2% (24) for donor agencies, and 12.4% (14) in the private sector. Annual incidence of physician migration was estimated to be 3.7%, predominately to work in the growing NGO sector. An estimated 36.3% (41/113) of internal migration cases had previously held senior-level management positions in the public sector. Discussion Internal migration is an important contributor to capital flight from the public sector, accounting for more cases of physician loss than external migration in Mozambique. Given the urgent need to strengthen public sector health systems, frank reflection by donors and NGOs is needed to assess how hiring practices may undermine the very systems they seek to strengthen. PMID:22558237

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.

Pressure-controlled drainage of cerebrospinal fluid: clinical experience with a new type of ventricular catheter (Ventcontrol MTC)and an integrated Piezo-resistive sensor at its tip: technical note.

PubMed

Piek, J; Raes, P

1996-01-01

We described a new ventricular catheter that is the combination of a "classic" ventricular catheter with a piezo-resistive transducer at its tip. The device allows parallel recordings of intraventricular fluid pressure via a chip and a fluid-filled external transducer, drainage of cerebrospinal fluid from the ventricle or injection of fluid into the ventricle with simultaneous monitoring of intracranial pressure, and recording of brain tissue pressure in cases of misplacement or dislocation of the ventricular catheter or in cases of progressively narrowing ventricles caused by brain edema. Clinical tests in various situations at different pressure ranges (total recording time, 1356 h in 13 patients) gave excellent correlations of both pressures. Application of the device is especially indicated in clinical situations in which pressure-controlled drainage is desirable, occlusion of ventricular bolts is likely, or pressure-volume tests are needed.

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.

Association Between Echocardiography Laboratory Accreditation and the Quality of Imaging and Reporting for Valvular Heart Disease.

PubMed

Thaden, Jeremy J; Tsang, Michael Y; Ayoub, Chadi; Padang, Ratnasari; Nkomo, Vuyisile T; Tucker, Stephen F; Cassidy, Cynthia S; Bremer, Merri; Kane, Garvan C; Pellikka, Patricia A

2017-08-01

It is presumed that echocardiographic laboratory accreditation leads to improved quality, but there are few data. We sought to compare the quality of echocardiographic examinations performed at accredited versus nonaccredited laboratories for the evaluation of valvular heart disease. We enrolled 335 consecutive valvular heart disease subjects who underwent echocardiography at our institution and an external accredited or nonaccredited institution within 6 months. Completeness and quality of echocardiographic reports and images were assessed by investigators blinded to the external laboratory accreditation status and echocardiographic results. Compared with nonaccredited laboratories, accredited sites more frequently reported patient sex (94% versus 78%; P <0.001), height and weight (96% versus 63%; P <0.001), blood pressure (86% versus 39%; P <0.001), left ventricular size (96% versus 83%; P <0.001), right ventricular size (94% versus 80%; P =0.001), and right ventricular function (87% versus 73%; P =0.006). Accredited laboratories had higher rates of complete and diagnostic color (58% versus 35%; P =0.002) and spectral Doppler imaging (45% versus 21%; P <0.0001). Concordance between external and internal grading of external studies was improved when diagnostic quantification was performed (85% versus 69%; P =0.003), and in patients with mitral regurgitation, reproducibility was improved with higher quality color Doppler imaging. Accredited echocardiographic laboratories had more complete reporting and better image quality, while echocardiographic quantification and color Doppler image quality were associated with improved concordance in grading valvular heart disease. Future quality improvement initiatives should highlight the importance of high-quality color Doppler imaging and echocardiographic quantification to improve the accuracy, reproducibility, and quality of echocardiographic studies for valvular heart disease. © 2017 American Heart Association, Inc.

Percutaneous fiber optic angioscopy of the left ventricle in patients with rheumatic valvular disease

NASA Astrophysics Data System (ADS)

Hirose, Junichi; Oshima, Tomomitsu; Fujimori, Yoshiharu; Uchida, Yasumi

1993-05-01

Recent advances in fiberoptic technology enabled us to observe percutaneously the cardiac chambers and valves. We examined left ventricular luminal and valvular changes by percutaneous fiberoptic angioscopy in patients with rheumatic valvular disease. Six patients with echocardiographic rheumatic changes in the mitral valves, underwent angioscopy during routine cardiac catheterization. The fiberscope 4.2 F in diameter, and the guiding catheter 9 F in external diameter with an inflatable balloon around the distal most tip were used for angioscopy. The left ventricular endocardial surface was diffusely white in color or white and brown in mosaic fashion. Echocardiography and angiography had low sensitivity for detecting the changes of the left ventricular luminal surface. Whitish changes which were observed by angioscopy were not related to the indices derived from echocardiography and angiography. The results indicate the possibility of percutaneous angioscopy in detecting left ventricular luminal changes in patients with rheumatic valvular disease.

Attenuating the defibrillation dosage decreases postresuscitation myocardial dysfunction in a swine model of pediatric ventricular fibrillation

PubMed Central

Berg, Marc D.; Banville, Isabelle L.; Chapman, Fred W.; Walker, Robert G.; Gaballa, Mohammed A.; Hilwig, Ronald W.; Samson, Ricardo A.; Kern, Karl B.; Berg, Robert A.

2009-01-01

Objective The optimal biphasic defibrillation dose for children is unknown. Postresuscitation myocardial dysfunction is common and may be worsened by higher defibrillation doses. Adult-dose automated external defibrillators are commonly available; pediatric doses can be delivered by attenuating the adult defibrillation dose through a pediatric pads/cable system. The objective was to investigate whether unattenuated (adult) dose biphasic defibrillation results in greater postresuscitation myocardial dysfunction and damage than attenuated (pediatric) defibrillation. Design Laboratory animal experiment. Setting University animal laboratory. Subjects Domestic swine weighing 19 ± 3.6 kg. Interventions Fifty-two piglets were randomized to receive biphasic defibrillation using either adult-dose shocks of 200, 300, and 360 J or pediatric-dose shocks of ~50, 75, and 85 J after 7 mins of untreated ventricular fibrillation. Contrast left ventriculograms were obtained at baseline and then at 1, 2, 3, and 4 hrs postresuscitation. Postresuscitation left ventricular ejection fraction and cardiac troponins were evaluated. Measurements and Main Results By design, piglets in the adult-dose group received shocks with more energy (261 ± 65 J vs. 72 ± 12 J, p < .001) and higher peak current (37 ± 8 A vs. 13 ± 2 A, p < .001) at the largest defibrillation dose needed. In both groups, left ventricular ejection fraction was reduced significantly at 1, 2, and 4 hrs from baseline and improved during the 4 hrs postresuscitation. The decrease in left ventricular ejection fraction from baseline was greater after adult-dose defibrillation. Plasma cardiac troponin levels were elevated 4 hrs postresuscitation in 11 of 19 adult-dose piglets vs. four of 20 pediatric-dose piglets (p = .02). Conclusions Unattenuated adult-dose defibrillation results in a greater frequency of myocardial damage and worse postresuscitation myocardial function than pediatric doses in a swine model of prolonged out-of-hospital pediatric ventricular fibrillation cardiac arrest. These data support the use of pediatric attenuating electrodes with adult biphasic automated external defibrillators to defibrillate children. PMID:18496405

Hollow mandrin facilitates external ventricular drainage placement.

PubMed

Heese, O; Regelsberger, J; Kehler, U; Westphal, M

2005-07-01

Placement of ventricular catheters is a routine procedure in neurosurgery. Ventricle puncture is done using a flexible ventricular catheter stabilised by a solid steel mandrin in order to improve stability during brain penetration. A correct catheter placement is confirmed after removing the solid steel mandrin by observation of cerebrospinal fluid (CSF) flow out of the flexible catheter. Incorrect placement makes further punctures necessary. The newly developed device allows CSF flow observation during the puncture procedure and in addition precise intracranial pressure (ICP) measurement. The developed mandrin is hollow with a blunt tip. On one side 4-5 small holes with a diameter of 0.8 mm are drilled corresponding exactly with the holes in the ventricular catheter, allowing CSF to pass into the hollow mandrin as soon as the ventricle is reached. By connecting a small translucent tube at the distal portion of the hollow mandrin ICP can be measured without loss of CSF. The system has been used in 15 patients with subarachnoid haemorrhage (SAH) or intraventricular haemeorrhage (IVH) and subsequent hydrocephalus. The new system improved the external ventricular drainage implantation procedure. In all 15 patients catheter placement was correct. ICP measurement was easy to perform immediately at ventricle puncture. In 4 patients at puncture no spontaneous CSF flow was observed, therefore by connecting a syringe and gentle aspiration of CSF correct placement was confirmed in this unexpected low pressure hydrocephalus. Otherwise by using the conventional technique further punctures would have been necessary. Advantages of the new technique are less puncture procedures with a lower risk of damage to neural structures and reduced risk of intracranial haemorrhages. Implantation of the ventricular catheter to far into the brain can be monitored and this complication can be overcome. Using the connected pressure monitoring tube an exact measurement of the opening intracranial pressure can be obtained performed without losing CSF.

[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.

Use of automated external defibrillators in US federal buildings: implementation of the Federal Occupational Health public access defibrillation program.

PubMed

Kilaru, Austin S; Leffer, Marc; Perkner, John; Sawyer, Kate Flanigan; Jolley, Chandra E; Nadkarni, Lindsay D; Shofer, Frances S; Merchant, Raina M

2014-01-01

Federal Occupational Health (FOH) administers a nationwide public access defibrillation program in US federal buildings. We describe the use of automated external defibrillators (AEDs) in federal buildings and evaluate survival after cardiac arrest. Using the FOH database, we examined reported events in which an AED was brought to a medical emergency in federal buildings over a 14-year period, from 1999 to 2012. There were 132 events involving an AED, 96 (73%) of which were due to cardiac arrest of cardiac etiology. Of 54 people who were witnessed to experience a cardiac arrest and presented with ventricular fibrillation or ventricular tachycardia, 21 (39%) survived to hospital discharge. Public access defibrillation, along with protocols to install, maintain, and deploy AEDs and train first responders, benefits survival after cardiac arrest in the workplace.

Use of Automated External Defibrillators in US Federal Buildings

PubMed Central

Kilaru, Austin S.; Leffer, Marc; Perkner, John; Sawyer, Kate Flanigan; Jolley, Chandra E.; Nadkarni, Lindsay D.; Shofer, Frances S.; Merchant, Raina M.

2014-01-01

Objective Federal Occupational Health (FOH) administers a nationwide public access defibrillation program in US federal buildings. We describe the use of automated external defibrillators (AEDs) in federal buildings and evaluate survival after cardiac arrest. Methods Using the FOH database, we examined reported events in which an AED was brought to a medical emergency in federal buildings over a 14-year period, from 1999 to 2012. Results There were 132 events involving an AED, 96 (73%) of which were due to cardiac arrest of cardiac etiology. Of 54 people who were witnessed to experience a cardiac arrest and presented with ventricular fibrillation or ventricular tachycardia, 21 (39%) survived to hospital discharge. Conclusions Public access defibrillation, along with protocols to install, maintain, and deploy AEDs and train first responders, benefits survival after cardiac arrest in the workplace. PMID:24351893

Mass transfer of pediatric tertiary care hospital inpatients to a new location in under 12 hours: lessons learned and implications for disaster preparedness.

PubMed

Fuzak, Julia K; Elkon, Benjamin D; Hampers, Louis C; Polage, Kathleen J; Milton, Jerrod D; Powers, Linda K; Percell-de'Shong, Karen; Wathen, Joseph E

2010-07-01

To report an experience with large-scale rapid transportation of hospitalized children, highlighting elements applicable to a disaster event. This was a retrospective study of the relocation of an entire pediatric inpatient population. Mitigation steps included postponement of elective procedures, implementation of planned discharges, and transfer of selected patients to satellite hospitals. Drills and simulations were used to estimate travel times and develop contingency plans. A transfer queue was modified as necessary to account for changing acuity. The Hospital Incident Command System was used. Thirteen critical care teams, 5 general crews, 2 vans, and 4 other vehicles transferred a total of 111 patients 8.5 miles in 11.6 hours. Patients were transferred along parallel (vs series) circuits, allowing simultaneous movement of patients from different areas. Sixty-four patients (including 32 infants) were considered critically ill; 24 of these patients required ventilator support, 3 required inhaled nitric oxide, 30 required continuous infusions, and 4 had an external ventricular drain. There were no adverse outcomes. Mass inpatient pediatric transfers can be managed rapidly and safely with parallel transfers. Preexisting agreements with regional pediatric teams are imperative. Disaster preparedness concepts, including preplanning, evacuation priorities, recovery analysis, and prevention/mitigation, can be applied to this event. Copyright (c) 2010 Mosby, Inc. All rights reserved.

Biventricular support with the Jarvik 2000 axial flow pump: a feasibility study.

PubMed

Radovancevic, Branislav; Gregoric, Igor D; Tamez, Daniel; Vrtovec, Bojan; Tuzun, Egemen; Chee, Hyun Keun; Moore, Sheila; Jarvik, Robert K; Frazier, O H

2003-01-01

Patients with congestive heart failure who are supported with a left ventricular assist device (LVAD) may experience right ventricular dysfunction or failure that requires support with a right ventricular assist device (RVAD). To determine the feasibility of using a clinically available axial flow ventricular assist device as an RVAD, we implanted Jarvik 2000 pumps in the left ventricle and right atrium of two Corriente crossbred calves (approximately 100 kg each) by way of a left thoracotomy and then analyzed the hemodynamic effects in the mechanically fibrillated heart at various LVAD and RVAD speeds. Right atrial implantation of the device required no modification of either the device or the surgical technique used for left ventricular implantation. Satisfactory biventricular support was achieved during fibrillation as evidenced by an increase in mean aortic pressure from 34 mm Hg with the pumps off to 78 mm Hg with the pumps generating a flow rate of 4.8 L/min. These results indicate that the Jarvik 2000 pump, which can provide chronic circulatory support and can be powered by external batteries, is a feasible option for right ventricular support after LVAD implantation and is capable of completely supporting the circulation in patients with global heart failure.

Cardiopulmonary physiology: why the heart and lungs are inextricably linked.

PubMed

Verhoeff, Kevin; Mitchell, Jamie R

2017-09-01

Because the heart and lungs are confined within the thoracic cavity, understanding their interactions is integral for studying each system. Such interactions include changes in external constraint to the heart, blood volume redistribution (venous return), direct ventricular interaction (DVI), and left ventricular (LV) afterload. During mechanical ventilation, these interactions can be amplified and result in reduced cardiac output. For example, increased intrathoracic pressure associated with mechanical ventilation can increase external constraint and limit ventricular diastolic filling and, therefore, output. Similarly, high intrathoracic pressures can alter blood volume distribution and limit diastolic filling of both ventricles while concomitantly increasing pulmonary vascular resistance, leading to increased DVI, which may further limit LV filling. While LV afterload is generally considered to decrease with increased intrathoracic pressure, the question arises if the reduced LV afterload is primarily a consequence of a reduced LV preload. A thorough understanding of the interaction between the heart and lungs can be complicated but is essential for clinicians and health science students alike. In this teaching review, we have attempted to highlight the present understanding of certain salient aspects of cardiopulmonary physiology and pathophysiology, as well as provide a resource for multidisciplined health science educators and students. Copyright © 2017 the American Physiological Society.

Monte Carlo simulations of spin transport in a strained nanoscale InGaAs field effect transistor

NASA Astrophysics Data System (ADS)

Thorpe, B.; Kalna, K.; Langbein, F. C.; Schirmer, S.

2017-12-01

Spin-based logic devices could operate at a very high speed with a very low energy consumption and hold significant promise for quantum information processing and metrology. We develop a spintronic device simulator by combining an in-house developed, experimentally verified, ensemble self-consistent Monte Carlo device simulator with spin transport based on a Bloch equation model and a spin-orbit interaction Hamiltonian accounting for Dresselhaus and Rashba couplings. It is employed to simulate a spin field effect transistor operating under externally applied voltages on a gate and a drain. In particular, we simulate electron spin transport in a 25 nm gate length In0.7Ga0.3As metal-oxide-semiconductor field-effect transistor with a CMOS compatible architecture. We observe a non-uniform decay of the net magnetization between the source and the gate and a magnetization recovery effect due to spin refocusing induced by a high electric field between the gate and the drain. We demonstrate a coherent control of the polarization vector of the drain current via the source-drain and gate voltages, and show that the magnetization of the drain current can be increased twofold by the strain induced into the channel.

Early feasibility evaluation of thoracoscopically assisted transcatheter ventricular reconstruction in an experimental model of ischaemic heart failure with left anteroapical aneurysm.

PubMed

Cheng, Yanping; Yi, Geng-Hua; Annest, Lon S; Van Bladel, Kevin; Brown, Ryan; Wechsler, Andrew; Shibuya, Masahiko; Conditt, Gerard B; Peppas, Athanasios; Kaluza, Greg L; Granada, Juan F

2015-04-01

To test the feasibility of a thoracoscopically assisted, off-pump, transcatheter ventricular reconstruction (TCVR) approach in an ovine model of left ventricular (LV) anteroapical aneurysm. Myocardial infarction (MI) was induced by coil occlusion of the middle left anterior descending artery and diagonals. Two months after MI creation, TCVR was performed via a minimal thoracotomy in eight sheep. Under endoscopic and fluoroscopic guidance, trans-interventricular septal puncture was performed from the LV epicardial scar. A guidewire was externalised via a snare placed in the right ventricle from the external jugular vein. An internal anchor was inserted over the wire and positioned on the right ventricular septum and an external anchor was deployed on the LV anterior epicardium. Serial pairs of anchors were placed and plicated together to exclude the scar completely. Immediately after TCVR, echocardiography showed LV end-systolic volume decreased from pre-procedure 58.8±16.6 ml to 25.1±7.6 ml (p<0.01) and the ejection fraction increased from 32.0±7.3% to 52.0±7.5% (p<0.01). LV twist significantly improved (3.83±2.21 vs. pre-procedure -0.41±0.94, p=0.01) and the global peak-systolic longitudinal strain increased from -5.64% to -10.77% (p<0.05). TCVR using minimally invasive access techniques on the off-pump beating heart is feasible and resulted in significant improvement in LV performance.

Accuracy of external ventricular drainage catheter placement.

PubMed

Abdoh, Mohammad Ghazi; Bekaert, Olivier; Hodel, Jérôme; Diarra, Salia Mamadou; Le Guerinel, Caroline; Nseir, Rémi; Bastuji-Garin, Sylvie; Decq, Philippe

2012-01-01

External ventricular drainage (EVD) is a freehand neurosurgical procedure performed routinely using the anatomical landmarks. The aim of this study was to determine the accuracy of EVD catheter freehand placement. Pre-operative and post-operative computed tomography scans for 66 consecutive EVDs performed in 56 adult patients (26 men, 30 women) in 2008 were retrospectively reviewed. Etiologies of acute hydrocephalus were subarachnoid or intraventricular haemorrhage (43 cases) or miscellaneous (13 cases). Pre-operative lateral ventricular volume, position of the burr hole, length of the catheter and its sagittal and coronal angular variations from a theoretical trajectory were measured. The EVD was placed on the right (53 cases) or left (13 cases) side. The mean pre-operative lateral ventricular volume was 51 cc (10-118 cc). The average distance from the burr hole to the midline was 28 mm (10-49 mm) and to the supra-orbital ridge was 101 mm (75-125 mm). The mean intracranial catheter length was 60 mm (from 39-102 mm). Only 50% of the EVDs in the coronal plane and 40% in the sagittal plane were placed with an angular variation of ±5° to the target. The tip was placed outside of the ventricles in three cases; 13 catheters crossed the midline, and five intracranial minor haemorrhages were detected. Freehand placement of EVDs does not have sufficient accuracy and may lead to drainage dysfunctions. This data suggests that a guidance system for EVD's would be required.

Cerebrospinal Fluid Leak at Percutaneous Exit of Ventricular Catheter as a Crucial Risk Factor for External Ventricular Drainage-Related Infection in Adult Neurosurgical Patients.

PubMed

Park, Jaechan; Choi, Yeon-Ju; Ohk, Boram; Chang, Hyun-Ha

2018-01-01

The placement of a ventricular catheter for temporary cerebrospinal fluid (CSF) diversion is associated with a considerable risk of CSF infection. The authors investigated the effect of a CSF leak on CSF-related infection and the predisposing factors for a CSF leak. Fifty-two patients who underwent external ventricular drainage (EVD) for acute hydrocephalus associated with a subarachnoid hemorrhage or intraventricular hemorrhage (IVH) were enrolled in this prospective study. A CSF leak-detection paper (small sterilized filter paper) was applied at the percutaneous catheter exit site to check for any bloody CSF leak. In addition, radiologic and clinical data were collected. Four of the 52 patients (7.7%) developed an EVD-related CSF infection from organisms including Staphylococcus epidermidis (n = 3) and Staphylococcus hominis (n = 1). A prolonged CSF leak >1 day was detected in 9 patients (17.3%) and revealed as a significant risk factor for CSF infection with a 44.4% positive predictive value. Moreover, an IVH >10 mL was found in 11 patients (21.2%) and revealed as a significant predisposing factor for a CSF leak at the percutaneous catheter exit. A prolonged CSF leak for >1 day at the percutaneous catheter exit site is a crucial risk factor for EVD-related CSF infection and an IVH >10 mL is a predisposing factor for a CSF leak. Copyright © 2017 Elsevier Inc. All rights reserved.

Remote cerebellar haemorrhage after placement of an external ventricular drainage for acute hydrocephalus: A case report.

PubMed

Caldeira, I; Lavrador, J; Basílio, G; Sousa, R; Reimão, S

2017-03-01

Remote cerebellar haemorrhage (RCH) is a rare complication following a craniotomy. This generally benign phenomenon is an identifiable complication of supratentorial craniotomies and should not be mistaken with other pathologies. The most common presenting symptom is a decrease in the level of consciousness but in some cases the RCH may be asymptomatic and accidentally discovered in follow-up CT scans. A 70-year-old man was admitted to our emergency department with sudden mental status deterioration. A head CT scan was carried out and an acute hydrocephalus was diagnosed. The patient was transferred to the operating room for external ventricular drainage (EVD) placement via a frontal burr-hole. At 24hours, the patient made a complete neurological recovery. On third postoperative day, a follow-up CT scan showed an asymptomatic right remote cerebellar haemorrhage. The MRI assessment confirmed the diagnosis. The EVD was removed on the 6th postoperative day and the patient was discharged after one week with no further symptoms. This case report is the first documented case, to our knowledge, of a remote cerebellar haemorrhage after placement of external ventricular drainage via a frontal burr-hole. The precise aetiology of remote cerebellar haemorrhage remains unclear. One of the most accepted theories is the "cerebellar sag" explanation, which defends hypothesis that peri-operative over drainage of cerebrospinal fluid (CSF) is the main mechanism involved. Further investigation is required to understand the pathogenesis and risk factors for the occurrence of this phenomenon. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

[Quality of life in patients with urolithiasis depending on methods of drainage of the upper urinary tract].

PubMed

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

2010-01-01

A sociological study was made of quality of life of 60 patients with nephrostomic drainage and 71 patients with an ureteral stent according to standard international questionnaires SF-36 and EORTC QLQ-C30, version 3.0. It was found that both internal and external drain significantly aggravate quality of life in the same degree. Younger patients of both groups suffered less. Quality of life was higher in both groups in drainage duration up to 1 month (p < 0.05), in 1 to 6 month draining quality of life is worse in both groups. Internal drainage is worse tolerated by males aged 25-44 years and elderly women aged 60-75 years, especially in long-term drain (over 6 months). Internal drainage is worse tolerated by elderly females (60-75 years of age) and senile women (over 75 years) in 6 month and longer drainage. The study of large number of patients revealed significant differences in quality of life in patients with nephrostomic drain and ureteral stent.

Accurate recognition and effective treatment of ventricular fibrillation by automated external defibrillators in adolescents.

PubMed

Atkins, D L; Hartley, L L; York, D K

1998-03-01

To evaluate the accuracy and efficacy of automated external defibrillators (AEDs) in patients <16 years old. AEDs are standard therapy in out-of-hospital resuscitation of adults and have led to higher success rates. Their use in children and adolescents has never been evaluated, despite recommendations from the American Heart Association that they be used in children >8 years of age. This was a retrospective cohort study of children <16 years old who underwent out-of-hospital cardiac resuscitation and on whom an AED was used during the resuscitation. The setting was rural and urban prehospital emergency medical systems. Patients were identified by review of a database of cardiac arrests maintained by a large surveillance program of these services. AEDs were used to assess cardiac rhythm in 18 patients with a mean age of 12.1 +/- 3.7 years. The cardiac rhythms were analyzed 67 times and included ventricular fibrillation (25), asystole/pulseless electrical activity (32), sinus bradycardia (6), and sinus tachycardia (4). The AEDs recognized all nonshockable rhythms accurately and advised no shock. Ventricular fibrillation was recognized accurately in 22 (88%) of 25 episodes and advised or administered a shock 22 times. Sensitivity and specificity for accurate rhythm analysis were 88% and 100%, respectively. One patient with a nonshockable rhythm survived, whereas 3 of 9 patients with ventricular fibrillation survived. These data furnish evidence that AEDs provide accurate rhythm detection and shock delivery to children and young adolescents. AED use is potentially as effective for children as it is for adults.

External heart deformities in passerine birds exposed to environmental mixtures of polychlorinated biphenyls during development.

PubMed

DeWitt, Jamie C; Millsap, Deborah S; Yeager, Ronnie L; Heise, Steve S; Sparks, Daniel W; Henshel, Diane S

2006-02-01

Necropsy-observable cardiac deformities were evaluated from 283 nestling passerines collected from one reference site and five polychlorinated biphenyl (PCB)-contaminated sites around Bloomington and Bedford, Indiana, USA. Hearts were weighed and assessed on relative scales in three dimensions (height, length, and width) and for externally visible deformities. Heart weights normalized to body weight (heart somatic index) were decreased significantly at the more contaminated sites in both house wren (Troglodytes aedon) and tree swallow (Tachycineta bicolor). Heart somatic indices significantly correlated with log PCB concentrations in Carolina chickadee (Parus carolinesis) and tree swallow and with log 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent values in tree swallow alone. Ventricular length was increased significantly in eastern bluebirds (Sialia sialis) and decreased significantly in Carolina chickadee and tree swallow from contaminated sites versus the reference site. Heart length regressed significantly against the log PCB concentrations (Carolina chickadee and tree swallow) or the square of the PCB concentrations (red-winged blackbird [Agelaius phoeniceus]) in a sibling bird. The deformities that were observed most at the contaminated sites included abnormal tips (pointed, rounded, or flattened), center rolls, macro- and microsurface roughness, ventricular indentations on the ventral or dorsal surface, lateral ventricular notches, visibly thin ventricular walls, and changes in overall heart shape. A pooled heart deformity index regressed significantly against the logged contaminant concentrations for all species except red-winged blackbird. These results indicate that developmental changes in heart morphometrics and shape abnormalities are quantifiable and may be sensitive and useful indicators of PCB-related developmental impacts across many avian species.

Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators.

PubMed

Berg, Robert A

2004-09-01

To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation. Review relevant human and animal literature. Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children. Theoretical considerations and transthoracic impedance data from animals and children suggest that pediatric defibrillation doses should not necessarily vary in a simple weight-based manner. Two piglet studies have established that an attenuated adult biphasic dosage can be successfully used for 3.5- to 24-kg animals in ventricular fibrillation. One study established that the attenuated adult biphasic dosage was at least as safe and effective as the standard monophasic weight-based dosing. This review supports the American Heart Association's new guidelines for pediatric automated external defibrillator usage: "Automated external defibrillators may be used for children 1 to 8 yrs of age who have no signs of circulation. Ideally the device should deliver a pediatric dose. The arrhythmia detection system used in the device should demonstrate high specificity for pediatric shockable rhythms, i.e., it will not recommend delivery of a shock for nonshockable rhythms."

Effects of a prostagrandin EP4-receptor agonist ONO-AE1-329 on the left ventricular pressure-volume relationship in the halothane-anesthetized dogs.

PubMed

Honda, Atsushi; Nakamura, Yuji; Ohara, Hiroshi; Cao, Xin; Nomura, Hiroaki; Katagi, Jun; Wada, Takeshi; Izumi-Nakaseko, Hiroko; Ando, Kentaro; Sugiyama, Atsushi

2016-03-15

Cardiac effects of a prostagrandin EP4-receptor agonist ONO-AE1-329 were assessed in the halothane-anesthetized dogs under the monitoring of left ventricular pressure-volume relationship, which were compared with those of clinically recommended doses of dopamine, dobutamine and milrinone (n=4-5 for each treatment). ONO-AE1-329 was intravenously administered in doses of 0.3, 1 and 3 ng/kg/min for 10 min with a pause of 20 min. Dopamine in a dose of 3 µg/kg/min for 10 min, dobutamine in a dose of 1 µg/kg/min for 10 min and milrinone in a dose of 5 µg/kg/min for 10 min followed by 0.5 µg/kg/min for 10 min were intravenously administered. Low dose of ONO-AE1-329 increased the stroke volume. Middle dose of ONO-AE1-329 increased the cardiac output, left ventricular end-diastolic volume, ejection fraction, maximum upstroke/downstroke velocities of the left ventricular pressure and external work, but decreased the end-systolic pressure and internal work besides the change by the low dose. High dose of ONO-AE1-329 increased the heart rate and maximum elastance, but decreased the end-systolic volume besides the changes by the middle dose. Dopamine, dobutamine and milrinone exerted essentially similar cardiac effects to ONO-AE1-329, but they did not significantly change the end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, end-systolic pressure, maximum elastance, external work or internal work. Thus, EP4-receptor stimulation by ONO-AE1-329 may have potential to better promote the passive ventricular filling than the conventional cardiotonic drugs, which could become a candidate of novel therapeutic strategy for the treatment of heart failure with preserved ejection fraction. Copyright © 2016 Elsevier B.V. All rights reserved.

Use of Ventricular Assist Device in Univentricular Physiology: The Role of Lumped Parameter Models.

PubMed

Di Molfetta, Arianna; Ferrari, Gianfranco; Filippelli, Sergio; Fresiello, Libera; Iacobelli, Roberta; Gagliardi, Maria G; Amodeo, Antonio

2016-05-01

Failing single-ventricle (SV) patients might benefit from ventricular assist devices (VADs) as a bridge to heart transplantation. Considering the complex physiopathology of SV patients and the lack of established experience, the aim of this work was to realize and test a lumped parameter model of the cardiovascular system, able to simulate SV hemodynamics and VAD implantation effects. Data of 30 SV patients (10 Norwood, 10 Glenn, and 10 Fontan) were retrospectively collected and used to simulate patients' baseline. Then, the effects of VAD implantation were simulated. Additionally, both the effects of ventricular assistance and cavopulmonary assistance were simulated in different pathologic conditions on Fontan patients, including systolic dysfunction, diastolic dysfunction, and pulmonary vascular resistance increment. The model can reproduce patients' baseline well. Simulation results suggest that the implantation of VAD: (i) increases the cardiac output (CO) in all the three palliation conditions (Norwood 77.2%, Glenn 38.6%, and Fontan 17.2%); (ii) decreases the SV external work (SVEW) (Norwood 55%, Glenn 35.6%, and Fontan 41%); (iii) increases the mean pulmonary arterial pressure (Pap) (Norwood 39.7%, Glenn 12.1%, and Fontan 3%). In Fontan circulation, with systolic dysfunction, the left VAD (LVAD) increases CO (35%), while the right VAD (RVAD) determines a decrement of inferior vena cava pressure (Pvci) (39%) with 34% increment of CO. With diastolic dysfunction, the LVAD increases CO (42%) and the RVAD decreases the Pvci. With pulmonary vascular resistance increment, the RVAD allows the highest CO (50%) increment with the highest decrement of Pvci (53%). The single ventricular external work (SVEW) increases (decreases) increasing the VAD speed in cavopulmonary (ventricular) assistance. Numeric models could be helpful in this challenging and innovative field to support patients and VAD selection to optimize the clinical outcome and personalize the therapy. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Endoscopic transaqueductal placement of a single-catheter cyst-ventriculoperitoneal shunt in a neonate with Dandy-Walker malformation-associated hydrocephalus: case report.

PubMed

Morigaki, Ryoma; Pooh, Kyong-Hon; Nakagawa, Yoshinobu

2011-01-01

A neonate with hydrocephalus associated with Dandy-Walker malformation was successfully treated with an endoscopic placement of a transaqueductal ventricular single catheter. The modified catheter was provided with additional fenestration on its proximal side to allow simultaneous drainage from both the supra- and infratentorial compartments. This technique is well known for isolated fourth ventricles, but has not been applied to hydrocephalus associated with Dandy-Walker malformation. The cyst-ventriculoperitoneal shunt effectively drained both compartments. The patient was doing well 18 months after the surgical procedure. Endoscopic transaqueductal shunt placement can be considered, especially in patients with aqueductal patency.

Endoscopic transpapillary drainage for external fistulas developing after surgical or radiological pancreatic interventions.

PubMed

Rana, Surinder Singh; Bhasin, Deepak Kumar; Nanda, Mohit; Siyad, Ismail; Gupta, Rajesh; Kang, Mandeep; Nagi, Birinder; Singh, Kartar

2010-06-01

External pancreatic fistulas (EPFs) are a therapeutic challenge. The present study was conducted to evaluate the efficacy of endoscopic transpapillary nasopancreatic drainage (NPD) in patients with EPF. Over 12 years, 23 patients (19 males) with EPF underwent attempted endoscopic transpapillary NPD. The end points were fistula closure with healing of pancreatic duct disruption on nasopancreatogram, or need for surgery. All 23 patients had persistent drain output (>50 mL/day) for >6 weeks. The mean output volume of the fistula was 223 mL (range: 60 mL to 750 mL). Sixteen patients had partial and seven patients had complete pancreatic duct disruption. The NPD could be successfully placed in 21/23 (91.3%) patients. Disruption was bridged in 15 of 16 patients with partial duct disruption. EPF healed in 2-8 weeks of placement of NPD in all of the patients with partial duct disruption that was bridged and there was no recurrence at a mean follow-up of 38 months. The EPF resolved in only 2/6 (33%) patients with complete duct disruption. External pancreatic fistulas developing following percutaneous drainage of pancreatic fluid collections or surgical necrosectomy can be effectively treated by transpapillary nasopancreatic drain placement especially when there is partial ductal disruption and the disruption can be bridged.

Perioperative management of calves undergoing implantation of a left ventricular assist device.

PubMed

Wilson, D V; Kantrowitz, A; Pacholewicz, J; Salat, O; Paules, B R; Zhou, Y; Dawe, E J

2000-01-01

To describe perioperative management of calves that underwent left lateral thoracotomy, aortic cross-clamping, partial left heart bypass and implantation of a left ventricular assist device. A total of 43 healthy castrated male calves, weighing 121 +/- 24 kg. Diazepam (mean +/- SD, 0.26 +/- 0.07 mg/kg), ketamine (5.9 +/- 2.17 mg/kg) and isoflurane were used in the anesthetic management of calves undergoing implantation of a left ventricular assist device in the descending thoracic aorta. Other adjunctive agents administered were fentanyl (11 +/- 5.4 microg/kg), lidocaine (4.9 +/- 3.19 mg/kg), bupivacaine (0.75%) and butorphanol (0.49 +/- 0.13 mg/kg). None of the calves regurgitated at induction or during intubation. A tube was used to drain the rumen and prevent bloat during the procedure. Partial left heart bypass was used to perfuse the caudal half of the body during the period of aortic cross clamp and device implantation. Initial mean systemic blood pressure was 96 +/- 25 mm Hg, and pressures measured in the auricular artery increased during aortic cross-clamping and bypass. Vasoconstrictor therapy was required to treat caudal arterial hypotension during the procedure in 9 calves. Mean systemic arterial pressures returned to baseline values by the end of the anesthetic period. Initial mean pulmonary arterial pressures (PAP) were 22 +/- 3 mm Hg. A significant but transient increase in pulmonary arterial pressure occurred after both heparin and protamine administration. The described anesthetic protocol was effective for thoracotomy and implantation of an intra-aortic left ventricular assist device in normal calves. Partial left ventricular bypass was a useful adjunct during the period of aortic cross clamp. The doses of heparin and protamine administered were effective. Responsibility to monitor oxygenation of the cranial half of the animal continues during the bypass period as hypoxemia due to pulmonary dysfunction will not be detected by the perfusionist.

Needs Assessment for Incoming PGY-1 Residents in Neurosurgical Residency.

PubMed

Brandman, David M; Haji, Faizal A; Matte, Marie C; Clarke, David B

2015-01-01

Residents must develop a diverse range of skills in order to practice neurosurgery safely and effectively. The purpose of this study was to identify the foundational skills required for neurosurgical trainees as they transition from medical school to residency. Based on the CanMEDS competency framework, a web-based survey was distributed to all Canadian academic neurosurgical centers, targeting incoming and current PGY-1 neurosurgical residents as well as program directors. Using Likert scale and free-text responses, respondents rated the importance of various cognitive (e.g. management of raised intracranial pressure), technical (e.g. performing a lumbar puncture) and behavioral skills (e.g. obtaining informed consent) required for a PGY-1 neurosurgical resident. Of 52 individuals contacted, 38 responses were received. Of these, 10 were from program directors (71%), 11 from current PGY-1 residents (58%) and 17 from incoming PGY-1 residents (89%). Respondents emphasized operative skills such as proper sterile technique and patient positioning; clinical skills such as lesion localization and interpreting neuro-imaging; management skills for common scenarios such as raised intracranial pressure and status epilepticus; and technical skills such as lumbar puncture and external ventricular drain placement. Free text answers were concordant with the Likert scale results. We surveyed Canadian neurosurgical program directors and PGY-1 residents to identify areas perceived as foundational to neurosurgical residency education and training. This information is valuable for evaluating the appropriateness of a training program's goals and objectives, as well as for generating a national educational curriculum for incoming PGY-1 residents.

The Causes and Treatment Outcomes of 91 Patients with Adult Nosocomial Meningitis

PubMed Central

Kim, Hye-In; Park, Ga-Young; Kwon, Eu-Gene; Kim, Hyo-Hoon; Jeong, Ju-Young; Chang, Hyun-Ha; Lee, Jong-Myung; Kim, Neung-Su

2012-01-01

Background/Aims Frequent pathogens of nosocomial meningitis were investigated and the adequacy of empiric antibiotic therapy was assessed. Outcomes of nosocomial meningitis were also evaluated. Methods Ninety-one patients, who were diagnosed and treated for nosocomial meningitis at a single tertiary hospital in Daegu, Korea for 10 years, were included. Medical record and electronic laboratory data on the causative pathogens, antibiotics used, and outcomes were retrospectively investigated. Results Coagulase-negative Staphylococcus (40.9%) was the most common pathogen, followed by Acinetobacter (32.5%). Both were cultured as a single organism in cerebrospinal fluid (CSF). Seventy-eight patients (85.7%) had infections related to external ventricular drains (EVD). The most common empirical antibiotics were extended-spectrum beta-lactam antibiotics plus vancomycin (35/91, 38.6%). Of the 27 patients who had cultured Acinetobacter in CSF, 10 (37%) were given the wrong empirical antibiotic treatment. Seven of the 27 patients (26.9%) with cultured Acinetobacter died, and overall mortality of the 91 patients was 16.5%. In the multivariate analysis, the presence of combined septic shock (p < 0.001) and a persistent EVD state (p = 0.021) were associated with a poor prognosis. Conclusions Acinetobacter is one of the leading pathogens of nosocomial meningitis and may lead to inadequate coverage of empiric antibiotic therapy due to increasing resistance. An EVD should be removed early in cases of suspected nosocomial meningitis, and carbapenem might be required for the poor treatment response. PMID:22707889

Intramyocardial pressure gradients in working and nonworking isolated cat hearts.

PubMed

Mihailescu, L S; Abel, F L

1994-03-01

This study presents an improved method for the measurement of intramyocardial pressure (IMP) using the servo-nulling mechanism. Glass micropipettes (20-24 microns OD) were used as transducers, coated to increase their mechanical resistance to breakage, and placed inside the left ventricular wall with a micropipette holder and manipulator. IMP was measured at the base of the left ventricle in working and nonworking isolated cat hearts that were perfused with Krebs-Henseleit buffer. In working hearts a transmural gradient of systolic IMP oriented from endocardium toward the epicardium was found; the endocardial values for systolic IMP were slightly higher than systolic left ventricular pressure (LVP), by 11-18%. Increases in afterload induced increases in IMP, without changing the systolic IMP-to-LVP ratio. In nonworking hearts with drained left ventricles, the systolic transmural gradient for IMP described for working hearts persisted, but at lower values, and was directly dependent on coronary perfusion pressure. Systolic IMP-to-LVP ratios were always > 1. The diastolic IMP of both working and nonworking hearts exhibited irregular transmural gradients. Our results support the view that generated systolic IMP is largely independent of LVP development.

Infectious complications related to external ventricular shunt. Incidence and risk factors.

PubMed

López-Amor, L; Viña, L; Martín, L; Calleja, C; Rodríguez-García, R; Astola, I; Forcelledo, L; Álvarez-García, L; Díaz-Gómez, C; Fernández-Domínguez, J; Vázquez, F; Escudero, D

2017-10-01

Infectious complications related to external ventricular shunt (ICREVS) are a main problem in neurocritical intensive care units (ICU). The aim of the review is to assess the incidence of ICREVS and to analyse factors involved. Retrospective analysis, adult polyvalent ICU in a third level reference hospital. Patients carrying external ventricular shunt (DVE) were included. Those patients with central nervous system infection diagnosed prior DVE placement were excluded. 87 patients were included with 106 DVE. Most common admittance diagnosis was subarachnoid haemorrhage (49.4%). 31 patients with 32 DVE developed an ICREVS. Infection rate is 19.5 per 1000 days of shunt for ICREVS and 14 per 1000 days for ventriculitis. 31.6% of the patients developed ICREVS and 25.3% ventriculitis. Patients who developed ICREVS presented higher shunt manipulations (2.0 ± 0.6 vs. 3.26 ± 1.02, p=0.02), shunt repositioning (0.1 ± 0.1 vs. 0.2 ± 0.1) and ICU and hospital stay (29.8 ± 4.9 vs 49.8 ± 5.2, p<0.01 y 67.4 ± 18.8 vs. 108.9 ± 30.2, p=0.02. Those DVE with ICREVS were placed for longer not only at infection diagnosis but also at removal (12.6 ± 2.1 vs. 18.3 ± 3.6 and 12.6 ± 2.1 vs. 30.4 ± 7.3 days, p<0.01). No difference in mortality was found. One out of three patients with a DVE develops an infection. The risk factors are the number of manipulations, repositioning and the permanency days. Patients with ICREVS had a longer ICU and hospital average stay without an increase in mortality.

Keyhole Approach Combined With External Ventricular Drainage for Ruptured, Poor-Grade, Anterior Circulation Cerebral Aneurysms

PubMed Central

Zheng, Shu-Fa; Yao, Pei-Sen; Yu, Liang-Hong; Kang, De-Zhi

2015-01-01

Abstract Poor-grade ruptured anterior circulation cerebral aneurysms are frequently associated with severe vasospasm and high morbidity rates despite recent remarkable advances in endovascular coiling. Here, we explored the feasibility of keyhole approach combined with external ventricular drainage for ruptured, poor-grade, anterior circulation cerebral aneurysms. We retrospectively assessed the records of 103 patients with ruptured, Hunt and Hess grade IV or V, anterior circulation cerebral aneurysms. The patients were divided into 2 groups (conservative group and surgical group). In surgical group, patients were divided into 2 subgroups according to surgical time (within 24 hours and at 24–48 hours). Clinical outcome was assessed at the 6-month follow-up and categorized according to modified Rankin Scale (mRS) score. Twenty percent of patients (9/44) in conservative group obtained good outcome, while 54% (32/54) in surgical group (P < 0.05). Mortality was 73% in conservative group and 40% in surgical group, respectively. In surgical group, age, Hunt and Hess grade (IV or V), and timing of intervention (<24 hours or later) influenced the clinical outcome of the patients (P < 0.05), while sex, Fisher grade, hydrocephalus, the location of aneurysms, and cerebral vasospasm (CVS) not (P > 0.05). Furthermore, 65% of patients (22/34) operated within 24 hours after onset of hemorrhage had a good outcome compared with 20% of patients (5/25) operated at 24 to 48 hours in surgical group (P < 0.05). The results indicate that keyhole approach combined with external ventricular drainage is a safe and reliable treatment for ruptured, poor-grade, anterior circulation cerebral aneurysms in early stage, which will reduce mortality. PMID:26705215

Asymmetric and Symmetric Dimethylarginines are Markers of Delayed Cerebral Ischemia and Neurological Outcome in Patients with Subarachnoid Hemorrhage.

PubMed

Appel, Daniel; Seeberger, Miriam; Schwedhelm, Edzard; Czorlich, Patrick; Goetz, Alwin E; Böger, Rainer H; Hannemann, Juliane

2018-03-20

Delayed cerebral ischemia (DCI) is the major cause of lethality and neuronal damage in patients who survived the primary subarachnoid hemorrhage (SAH). Asymmetric and symmetric dimethylarginines (ADMA and SDMA) inhibit nitric oxide production from L-arginine via distinct mechanisms. Elevated ADMA levels are associated with vasospasm after SAH. We aimed to study the time course of ADMA and SDMA in plasma and ventricular cerebrospinal fluid (CSF) and their associations with DCI and outcome. We measured ADMA and SDMA in 34 SAH patients with an external ventricular drain at admission and on days 3, 6, 8, 12, and 15 and followed them up for clinical status and neurological outcome until 30 days post-discharge. DCI was defined as the appearance of new infarctions on cerebral computed tomography or magnetic resonance imaging. ADMA and SDMA plasma concentrations did not differ significantly at baseline between patients who suffered DCI (N = 14; 41%) and not; however, plasma ADMA reached a peak on days 8 and 15 after hemorrhage in patients with DCI (0.81-0.91 µmol/l). Baseline plasma L-arginine/ADMA ratio was significantly lower in patients with DCI (57.1 [34.3; 70.8] vs. 68.7 [55.7; 96.2]; p < 0.05). ADMA and SDMA concentrations in CSF were significantly higher in patients with DCI than without. In multivariable-adjusted linear regression models, CSF ADMA was negatively associated with the incidence of DCI (OR 0.03 [0.02-0.70]; p = 0.04), whereas CSF SDMA on the day of hemorrhage predicted poor neurological outcome until 30 days after discharge (OR 22.4 [1.21-416.02]; p = 0.04). Our study shows that ADMA and the L-arginine/ADMA ratio are associated with the incidence of DCI after SAH. By contrast, SDMA was associated with initial neuronal damage and poor neurological outcome after SAH. These data support the hypothesis that ADMA and L-arginine affect the pathophysiology of cerebral ischemia after SAH, while SDMA is a biomarker of neurological outcome after SAH.

Ventricular fibrillation and the use of automated external defibrillators on children.

PubMed

Markenson, David

2007-11-01

The use of automated external defibrillators (AEDs) has been advocated in recent years as one part of the chain of survival to improve outcomes for adult cardiac arrest victims. When AEDs first entered the market, they had not been tested for pediatric usage and rhythm interpretation. In addition, the presumption was that children do not experience ventricular fibrillation, so they would not benefit from the use of AEDs. Recent literature has shown that children do experience ventricular fibrillation, which has a better outcome than do other cardiac arrest rhythms. At the same time, the arrhythmia software on AEDs has become more extensive and validated for children, and attenuation devices have become available to downregulate the energy delivered by AEDs to allow their use on children. Pediatricians are now being asked whether AED programs should be implemented, and where they are being implemented, pediatricians are being asked to provide guidance on the use of them on children. As AED programs expand, pediatricians must advocate on behalf of children so that their needs are accounted for. For pediatricians to be able to provide guidance and ensure that children are included in AED programs, it is important for pediatricians to know how AEDs work, be up-to-date on the literature regarding pediatric fibrillation and energy delivery, and understand the role of AEDs as life-saving interventions for children.

[Automatic external defibrillator--mode of operation and clinical use].

PubMed

Wieneke, H; Konorza, T; Breuckmann, F; Reinsch, N; Erbel, R

2008-10-01

Every year about 100,000 persons die from sudden cardiac death (SCD) in Germany. Although many efforts have been undertaken, mortality remains high. Only 2 - 10% of patients with out-off hospital SCD can finally be discharged from hospital after resuscitation. Observational studies show that ventricular fibrillation and ventricular tachycardia are the primary arrhythmias underlying SCD. For both arrhythmias the main determinant for survival is the time between onset and termination by defibrillation. The chance of survival declines by 10% for every minute of delay. These findings prompted the concept of early defibrillation by first responders. Many studies have shown that non-medical professionals, like police men, firemen or security officers, often arrive at the patient more early than emergency medical service. Thus, "smart" automated external defibrillators (AEDs), designed to identify VT/VF and prompt the user when to deliver a shock were introduced. These devices allow lay rescuers to terminate ventricular arrhythmias before the arrival of medical professionals. By this approach the time to defibrillation could be reduced and a significant reduction in mortality could be documented in selected situation. These encouraging results initialled the installation of AED at public places like aircrafts, airports, underground stations and shopping males. Due to the success of this approach doctors are more and more confronted with questions about technical details, reliability and cost effectiveness of these devices. The present review should give an overview about the current studies and guidelines.

T-tube drainage of the common bile duct choleperitoneum: etiology and management.

PubMed

Daldoul, S; Moussi, A; Zaouche, A

2012-06-01

External drainage of the common bile duct by placement of a T-tube is a common practice after choledochotomy. This practice may result in the specific complication of bile peritonitis due to leakage after removal of the T-tube. This complication has multiple causes: some are patient-related (corticotherapy, chemotherapy, ascites), and others are due to technical factors (inappropriate suturing of the drain to the ductal wall, minimal inflammatory reaction related to some drain materials). The clinical presentation is quite variable depending on the amount and rapidity of intra-peritoneal spread of of bile leakage. Abdominal ultrasound (US), with US-guided needle aspiration and occasionally Technetium(99) scintigraphy are useful for diagnosis. Traditional therapy consists of surgical intervention including peritoneal lavage and re-intubation of the choledochal fistulous tract to allow for a further period of external drainage. When leakage is walled off and well-tolerated, a more nuanced and less invasive conservative therapy may combine percutaneous drainage with endoscopic placement of a trans-ampullary biliary drainage. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Myocardial mechanics, energetics, and hemodynamics during intraaortic balloon and transvalvular axial flow hemopump support with a bovine model of ischemic cardiac dysfunction.

PubMed

Marks, J D; Pantalos, G M; Long, J W; Kinoshita, M; Everett, S D; Olsen, D B

1999-01-01

Unlike the mechanisms of intraaortic balloon pump (IABP) support, the mechanisms by which transvalvular axial flow Hemopump (HP) support benefit dysfunctional myocardium are less clearly understood. To help elucidate these mechanisms, hemodynamic, metabolic, and mechanical indexes of left ventricular function were measured during conditions of control, ischemic dysfunction, IABP support, and HP support. A large animal (calf) model of left ventricular dysfunction was created with multiple coronary ligations. Peak intraventricular pressure increased with HP support and decreased with IABP support. Intramyocardial pressure (an indicator of intramyocardial stress), time rate of pressure change (an indicator of contractility), and left ventricular myocardial oxygen consumption decreased with IABP and HP support. Left ventricular work decreased with HP support and increased with IABP support. During HP support, indexes of wall stress, work, and contractility, all primary determinants of oxygen consumption, were reduced. During IABP support, indexes of wall stress and contractility were reduced and external work increased. These changes were attributed primarily to changes in ventricular preload, and geometry for HP support, and to a reduction in afterload for IABP support. These findings support the hypothesis that both HP and IABP support reduce intramyocardial stress development and the corresponding oxygen consumption, although via different mechanisms.

Is the blocking of drainage channels in upland peats an effective means of reducing DOC loss at the catchment scale?

NASA Astrophysics Data System (ADS)

Turner, Kate; Worrall, Fred

2010-05-01

Only 3% of the earths land surface is covered by peatland yet boreal and subarctic peatlands store approximately 15-30% of the World's soil carbon as peat (Limpens et al. 2008). In comparison British bogs store carbon equivalent to 20 years worth of national emissions. The loss of carbon from these areas in the form of dissolved organic carbon (DOC) is increasing and it is expected to have grown by up to 40% by 2018. Extensive drainage of UK peatlands has been associated with dehydration of the peat, an increase in water colour and a loss of carbon storage. It has been considered that the blocking of these drainage channels represents a means of peat restoration and a way of reducing DOC loss. This study aims to assess the effectiveness of this drain blocking at both an individual drain scale and at a larger catchment scale. Gibson et al. (2009) considered the effects of blocking at a solely individual drain scale finding that a 20% drop in DOC export was recorded post blocking however this decrease was due to a reduction in water yield rather than a reduction in DOC concentration with the concentration record showing no significant reduction. The effect of external parameters become more pronounced as the DOC record is examined at larger scales. The catchment is an open system and water chemistry will be influence by mixing with water from other sources. Also it is likely that at some point the drains will cut across slope leading to the flow of any highly coloured water down slope, bypassing the blockages, and entering the surface waters downstream. Degradation of DOC will occur naturally downstream due to the effects of light and microbial activity. There is, consequently, a need to examine the wider effects of drain blocking at a catchment scale to ensure that what is observed for one drain transfers to the whole catchment. A series of blocked and unblocked catchments were studied in Upper Teesdale, Northern England. Drain water samples were taken at least daily at nine localities. These sites were located such that individual drains could be monitored in the context of a larger catchment. Water table depth, flow and weather parameters were recorded along with the collection of runoff and soil water samples. A detailed sampling programme was undertaken in which a series of drains were studied in the 12 months prior to and post blocking. This approach has allowed the effects of blocking on the carbon budget, water balance and flow pathways to be considered. Results indicate that the blocking of zero order drainage channels leads to a decrease in DOC export on an individual drain scale. However, this is due to a reduction in water yield rather than concentration. Concentrations are seen to rise by a small yet statistically significant amount in blocked zero order streams. The effect at a larger scale is more complex. Annual export values in the unblocked control catchment show a rise from zero to first order streams indicating that water is being added to the system at this scale from external spatially variable sources. This pattern is also recognised in the blocked catchment. The DOC concentration record in blocked drains at this larger scale however indicated a reduction relative to the unblocked catchment. This reduction points to a change in flow pathways post blocking as highly coloured water re-navigates its way downstream. References: Gibson H, Worrall F, Burt TP, Adamson JK (2009) DOC budgets of drained peat catchments: implications for DOC production in peat soils, Hydrological Processes 23(13) 1901-1911 Limpens J (2008) Peatlands and the carbon cycle: from local processes to global implications- a synthesis, Biogeosciences 5 1475-1491

Moisture and Thermal Conductivity of Lightweight Block Walls

NASA Astrophysics Data System (ADS)

Joosep, R.

2015-11-01

This article examines thermal properties of lightweight block walls and their changes over the course of time. Three different types of lightweight blocks and two types of heat insulation are used in construction. Aeroc aerated concrete blocks are in use, as well as compacted LECA (Lightweight Expanded Clay Aggregate) Fibo blocks made from burned clay and Silbet blocks produced from oil shale ash. Expanded Thermisol EPS60F polystyrene plates and glass wool Isover OL-P plates are used for thermal insulation. The actual and computational values of thermal conductivity and the water draining properties of walls over time are compared in this article. Water draining from glass wool walls is relatively fast. Water-draining can take over a year in polystyrene insulated walls. All four wall constructions can be used as external walls, but care must be taken regarding the moisture content of the blocks during construction (the construction should be handled with care to minimise the moisture in the blocks), especially in polystyrene board-insulated walls.

The role of the wearable cardioverter defibrillator in clinical practice.

PubMed

Chung, Mina K

2014-05-01

The wearable cardioverter defibrillator (WCD) is an option for external monitoring and defibrillation in patients at risk for sudden cardiac arrest caused by ventricular tachycardia or ventricular fibrillation and who are not candidates for or who refuse an implantable cardioverter defibrillator (ICD). WCDs provide monitoring with backup defibrillation protection. WCDs have been used when a patient's condition delays or prohibits ICD implantation, or as a bridge when an indicated ICD must be explanted. WCDs are used for primary prevention of sudden cardiac death during high-risk gap periods early after myocardial infarction, coronary revascularization, or new diagnosis of heart failure. Copyright © 2014 Elsevier Inc. All rights reserved.

Transvenous demand Pacemaker Treatment for intermittent complete Heart Block in a Cat.

PubMed

Forterre, S; Nürnberg, J H; Forterre, F; Skrodzki, M; Lange, P E

2001-11-01

A 13-year-old male neutered domestic shorthaired cat had repeated syncopal episodes over a 6 month period, which had variable duration and continued to increase in frequency. Intermittent ventricular asystole, due to complete heart block, and hyperthyroidism were documented. As the syncopal episodes did not respond to a 4-week medical treatment and symptoms became severe, a transvenous ventricular demand pacemaker system (VVIM) was implanted via the external jugular vein. The unipolar lead was tunneled subcutaneously and connected with the generator in a preformed ventral abdominal muscle pocket. During follow up of 18-months there were no recurrences of the syncopal episodes.

Feasibility of Leadless Cardiac Pacing Using Injectable Magnetic Microparticles

PubMed Central

Rotenberg, Menahem Y.; Gabay, Hovav; Etzion, Yoram; Cohen, Smadar

2016-01-01

A noninvasive, effective approach for immediate and painless heart pacing would have invaluable implications in several clinical scenarios. Here we present a novel strategy that utilizes the well-known mechano-electric feedback of the heart to evoke cardiac pacing, while relying on magnetic microparticles as leadless mechanical stimulators. We demonstrate that after localizing intravenously-injected magnetic microparticles in the right ventricular cavity using an external electromagnet, the application of magnetic pulses generates mechanical stimulation that provokes ventricular overdrive pacing in the rat heart. This temporary pacing consistently managed to revert drug-induced bradycardia, but could only last up to several seconds in the rat model, most likely due to escape of the particles between the applied pulses using our current experimental setting. In a pig model with open chest, MEF-based pacing was induced by banging magnetic particles and has lasted for a longer time. Due to overheating of the electromagnet, we intentionally terminated the experiments after 2 min. Our results demonstrate for the first time the feasibility of external leadless temporary pacing, using injectable magnetic microparticles that are manipulated by an external electromagnet. This new approach can have important utilities in clinical settings in which immediate and painless control of cardiac rhythm is required. PMID:27091192

Third Ventricular Cerebrospinal Fluid Cysts of Thalamic Origin: Review of Embryologic Origin, Presentation, and Management Strategies with a Case Series.

PubMed

Vasquez, Ciro A; Casey, Michael; Folzenlogen, Zach; Ormond, David R; Lillehei, Kevin; Youssef, A Samy

2017-07-01

Third ventricular cerebrospinal fluid (CSF) cysts of thalamic origin are rare. The objective of this study is to review their possible pathogenesis, clinical presentation, and management strategies with a case series describing management via an endoscopic approach with fenestration using a single burr-hole technique. A systematic literature review of reported cases of thalamic cysts was conducted with further meta-analysis of CSF cysts that involve the third ventricle. The mode of presentation, pathologic analysis, surgical management, and outcomes were analyzed. Twenty-two studies reported between 1990 and 2013 described 42 cases of thalamic cyst. Of those cases, 13 were consistent with CSF cyst that originated in the thalamus and involved the third ventricle. Eight cases (61.5%) were treated via endoscopic fenestration, 2 cases (15.4%) were surgically drained, 2 cases (15.4%) were stereotactically aspirated, and 1 case (7.69%) was observed. The most common presenting symptoms were gait disturbance (26.3%) and headaches (26.3%) followed by tremors (15.8%) and weakness (15.8%). In our series, a single burr-hole technique was a successful definitive treatment, with an average period of 23 months. Third ventricular CSF cysts of thalamic origin most commonly present with hydrocephalus. They can be safely definitively treated via endoscopic fenestration to the CSF circulation using a single burr-hole technique. Long-term follow-up shows lasting improvement in symptoms without reaccumulation of the cyst. Copyright © 2017 Elsevier Inc. All rights reserved.

Two hearts synchronized each other with a DDD pacemaker.

PubMed

Brunacci, Michele; Valbusa, Alberto; Brunelli, Claudio; Bertero, Giovanni

2016-12-01

: We describe the case of a patient with dyspnea and heterotopic cardiac transplant, ventricular fibrillation from the native heart and sinus rhythm from the transplanted one. The two hearts were synchronized with a pacemaker. Electric external cardioversion and a different type of pacemaker stimulation were successfully performed, with improving symptoms.

Chest Tube Drainage of the Pleural Space: A Concise Review for Pulmonologists.

PubMed

Porcel, José M

2018-04-01

Chest tube insertion is a common procedure usually done for the purpose of draining accumulated air or fluid in the pleural cavity. Small-bore chest tubes (≤14F) are generally recommended as the first-line therapy for spontaneous pneumothorax in non-ventilated patients and pleural effusions in general, with the possible exception of hemothoraces and malignant effusions (for which an immediate pleurodesis is planned). Large-bore chest drains may be useful for very large air leaks, as well as post-ineffective trial with small-bore drains. Chest tube insertion should be guided by imaging, either bedside ultrasonography or, less commonly, computed tomography. The so-called trocar technique must be avoided. Instead, blunt dissection (for tubes >24F) or the Seldinger technique should be used. All chest tubes are connected to a drainage system device: flutter valve, underwater seal, electronic systems or, for indwelling pleural catheters (IPC), vacuum bottles. The classic, three-bottle drainage system requires either (external) wall suction or gravity ("water seal") drainage (the former not being routinely recommended unless the latter is not effective). The optimal timing for tube removal is still a matter of controversy; however, the use of digital drainage systems facilitates informed and prudent decision-making in that area. A drain-clamping test before tube withdrawal is generally not advocated. Pain, drain blockage and accidental dislodgment are common complications of small-bore drains; the most dreaded complications include organ injury, hemothorax, infections, and re-expansion pulmonary edema. IPC represent a first-line palliative therapy of malignant pleural effusions in many centers. The optimal frequency of drainage, for IPC, has not been formally agreed upon or otherwise officially established. Copyright©2018. The Korean Academy of Tuberculosis and Respiratory Diseases.

Chest Tube Drainage of the Pleural Space: A Concise Review for Pulmonologists

PubMed Central

2018-01-01

Chest tube insertion is a common procedure usually done for the purpose of draining accumulated air or fluid in the pleural cavity. Small-bore chest tubes (≤14F) are generally recommended as the first-line therapy for spontaneous pneumothorax in non-ventilated patients and pleural effusions in general, with the possible exception of hemothoraces and malignant effusions (for which an immediate pleurodesis is planned). Large-bore chest drains may be useful for very large air leaks, as well as post-ineffective trial with small-bore drains. Chest tube insertion should be guided by imaging, either bedside ultrasonography or, less commonly, computed tomography. The so-called trocar technique must be avoided. Instead, blunt dissection (for tubes >24F) or the Seldinger technique should be used. All chest tubes are connected to a drainage system device: flutter valve, underwater seal, electronic systems or, for indwelling pleural catheters (IPC), vacuum bottles. The classic, three-bottle drainage system requires either (external) wall suction or gravity (“water seal”) drainage (the former not being routinely recommended unless the latter is not effective). The optimal timing for tube removal is still a matter of controversy; however, the use of digital drainage systems facilitates informed and prudent decision-making in that area. A drain-clamping test before tube withdrawal is generally not advocated. Pain, drain blockage and accidental dislodgment are common complications of small-bore drains; the most dreaded complications include organ injury, hemothorax, infections, and re-expansion pulmonary edema. IPC represent a first-line palliative therapy of malignant pleural effusions in many centers. The optimal frequency of drainage, for IPC, has not been formally agreed upon or otherwise officially established. PMID:29372629

Use of Cardiac Computed Tomography for Ventricular Volumetry in Late Postoperative Patients with Tetralogy of Fallot.

PubMed

Kim, Ho Jin; Mun, Da Na; Goo, Hyun Woo; Yun, Tae-Jin

2017-04-01

Cardiac computed tomography (CT) has emerged as an alternative to magnetic resonance imaging (MRI) for ventricular volumetry. However, the clinical use of cardiac CT requires external validation. Both cardiac CT and MRI were performed prior to pulmonary valve implantation (PVI) in 11 patients (median age, 19 years) who had undergone total correction of tetralogy of Fallot during infancy. The simplified contouring method (MRI) and semiautomatic 3-dimensional region-growing method (CT) were used to measure ventricular volumes. All volumetric indices measured by CT and MRI generally correlated well with each other, except for the left ventricular end-systolic volume index (LV-ESVI), which showed the following correlations with the other indices: the right ventricular end-diastolic volume index (RV-EDVI) (r=0.88, p<0.001), the right ventricular end-systolic volume index (RV-ESVI) (r=0.84, p=0.001), the left ventricular end-diastolic volume index (LV-EDVI) (r=0.90, p=0.001), and the LV-ESVI (r=0.55, p=0.079). While the EDVIs measured by CT were significantly larger than those measured by MRI (median RV-EDVI: 197 mL/m 2 vs. 175 mL/m 2 , p=0.008; median LV-EDVI: 94 mL/m 2 vs. 92 mL/m 2 , p=0.026), no significant differences were found for the RV-ESVI or LV-ESVI. The EDVIs measured by cardiac CT were greater than those measured by MRI, whereas the ESVIs measured by CT and MRI were comparable. The volumetric characteristics of these 2 diagnostic modalities should be taken into account when indications for late PVI after tetralogy of Fallot repair are assessed.

Using Arc/Info GIS to help implement the National Pollutant Discharge Elimination System (NPDES) stormwater permit for Los Angeles County

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

Levine, D.A.; Pace, P.J.; Woods, J.A.

1997-06-01

One of Los Angeles County Department of Public Works` many responsibilities is to manage non-point pollution that enters the storm drain network within Los Angeles County. The management of this non-point source pollution is mandated by the NPDES guidelines under the Federal Clean Water Act. These guidelines require the County to monitor the drainage network and the storm water and urban runoff flowing through it. The County covers over 3,117 square miles, with the NPDES Permit covering over 3,100 square miles and over 2500 miles of storm drains. A proposed solution to monitor and manage this vast geographic area ismore » centered upon an Arc/Info GIS. Some of the many concerns which need to be addressed include the administration and evaluation of Best Management Practices (BMP`s), storm drain inspection for illegal connections and illicit discharges, and pollutant load assessment and modeling. The storm drain network and other coverages will be related to external data bases currently used for facility management and planning. This system would be used for query purposes to perform spatial modeling and {open_quotes}what if{close_quotes} scenarios needed to create maps and reports required by the permit and to evaluate various BMP implementation strategies.« less

Cardiovascular pharmacology of quazodine (MJ-1988), with particular reference to effects of myocardial blood flow and metabolic heat production.

PubMed

Parratt, J R; Winslow, E

1971-06-01

1. The effects of intravenous infusions of quazodine (6,7-dimethoxy-4-ethylquinazoline; MJ-1988) on myocardial blood flow, myocardial metabolic heat production and on general haemodynamics have been studied in cats anaesthetized with sodium pentobarbitone.2. Quazodine (0.25 and 0.5 (mg/kg)/min for 10 min) decreased diastolic blood pressure, peripheral vascular resistance, systolic ejection time and left ventricular end-diastolic pressure. Heart rate, cardiac effort, output and external work and left ventricular dP/dt were markedly increased. These changes are indicative of increased myocardial contractility and peripheral vasodilatation.3. In a dose of (1.0 mg/kg)/min, quazodine had a more marked hypotensive effect, systolic pressure being significantly reduced, and had less effect on left ventricular dP/dt and cardiac effort. Calculated external cardiac work was slightly reduced and there were very occasional nodal arrhythmias.4. Changes in heart rate, aortic dP/dt and diastolic blood pressure induced by quazodine were unaffected by the previous administration of the beta-adrenoceptor blocking agent alprenolol in a dose (1.0 mg/kg) which abolished the effects of isoprenaline.5. In all doses, quazodine markedly increased local blood flow (by 70-540%) around an implanted myocardial heated thermocouple recorder. ;Corrected temperature', an index of local myocardial metabolic heat production, was almost unchanged and it is suggested that increased myocardial contractility, occurring with unchanged metabolic heat production and oxygen consumption, probably results from a concomitant decrease in intramural wall tension.

Complete trisomy 9 with unusual phenotypic associations: Dandy-Walker malformation, cleft lip and cleft palate, cardiovascular abnormalities.

PubMed

Tonni, Gabriele; Lituania, Mario; Chitayat, David; Bonasoni, Maria Paola; Keating, Sarah; Thompson, Megan; Shannon, Patrick

2014-12-01

Trisomy 9 is a rare chromosomal abnormality usually associated with first-trimester miscarriage; few fetuses survive until the second trimester. We report two new cases of complete trisomy 9 that both present unusual phenotypic associations, and we analyze the genetic pathway involved in this chromosomal abnormality. The first fetus investigated showed Dandy-Walker malformation, cleft lip, and cleft palate) at the second trimester scan. Cardiovascular abnormalities were characterized by a right-sided, U-shaped aortic arch associated with a ventricular septal defect (VSD). Symmetrical intrauterine growth restriction and multicystic dysplastic kidney disease were associated findings. The second fetus showed a dysmorphic face, bilateral cleft lip, hypoplastic corpus callosum, and a Dandy-Walker malformation. Postmortem examination revealed cardiovascular abnormalities such as persistent left superior vena cava draining into the coronary sinus, membranous ventricular septal defect, overriding aorta, pulmonary valve with two cusps and three sinuses, and the origin of the left subclavian artery distal to the junction of ductus arteriosus and aortic arch. Complete trisomy 9 may result in a wide spectrum of congenital abnormalities, and the presented case series contributes further details on the phenotype of this rare aneuploidy. Copyright © 2014. Published by Elsevier B.V.

Endoscopic third ventriculostomy

PubMed Central

Yadav, Yad Ram; Parihar, Vijay; Pande, Sonjjay; Namdev, Hemant; Agarwal, Moneet

2012-01-01

Endoscopic third ventriculostomy (ETV) is considered as a treatment of choice for obstructive hydrocephalus. It is indicated in hydrocephalus secondary to congenital aqueductal stenosis, posterior third ventricle tumor, cerebellar infarct, Dandy-Walker malformation, vein of Galen aneurism, syringomyelia with or without Chiari malformation type I, intraventricular hematoma, post infective, normal pressure hydrocephalus, myelomeningocele, multiloculated hydrocephalus, encephalocele, posterior fossa tumor and craniosynostosis. It is also indicated in block shunt or slit ventricle syndrome. Proper Pre-operative imaging for detailed assessment of the posterior communicating arteries distance from mid line, presence or absence of Liliequist membrane or other membranes, located in the prepontine cistern is useful. Measurement of lumbar elastance and resistance can predict patency of cranial subarachnoid space and complex hydrocephalus, which decides an ultimate outcome. Water jet dissection is an effective technique of ETV in thick floor. Ultrasonic contact probe can be useful in selected patients. Intra-operative ventriculo-stomography could help in confirming the adequacy of endoscopic procedure, thereby facilitating the need for shunt. Intraoperative observations of the patent aqueduct and prepontine cistern scarring are predictors of the risk of ETV failure. Such patients may be considered for shunt surgery. Magnetic resonance ventriculography and cine phase contrast magnetic resonance imaging are effective in assessing subarachnoid space and stoma patency after ETV. Proper case selection, post-operative care including monitoring of ICP and need for external ventricular drain, repeated lumbar puncture and CSF drainage, Ommaya reservoir in selected patients could help to increase success rate and reduce complications. Most of the complications develop in an early post-operative, but fatal complications can develop late which indicate an importance of long term follow up. PMID:22865970

Factors Associated with Acute and Chronic Hydrocephalus in Nonaneurysmal Subarachnoid Hemorrhage.

PubMed

Kang, Peter; Raya, Amanda; Zipfel, Gregory J; Dhar, Rajat

2016-02-01

Hydrocephalus requiring external ventricular drain (EVD) or shunt placement commonly complicates aneurysmal subarachnoid hemorrhage (SAH), but its frequency is not as well known for nonaneurysmal SAH (NA-SAH). Those with diffuse bleeding may have greater risk of hydrocephalus compared to those with a perimesencephalic pattern. We evaluated the frequency of hydrocephalus in NA-SAH and whether imaging factors could predict the need for EVD and shunting. We collected admission clinical and imaging variables for 105 NA-SAH patients, including bicaudate index (BI), Hijdra sum score (HSS), intraventricular hemorrhage (IVH) score, modified Fisher scale (mFS), and bleeding pattern. Hydrocephalus was categorized as acute (need for EVD) or chronic (shunt). We applied logistic regression to determine whether hydrocephalus risk was independently related to bleeding pattern or mediated through blood volume or ventriculomegaly. Acute hydrocephalus was seen in 26 (25%) patients but was more common with diffuse (15/28, 54%) versus perimesencephalic (10/59, 17%, p < 0.001) bleeding. Patients developing acute hydrocephalus had worse clinical grade and higher BI, HSS, and IVH scores. Adjusting the relationship between hydrocephalus and diffuse bleeding for HSS (but not BI) nullified this association. Nine (35%) patients requiring EVD eventually required shunting for chronic hydrocephalus, which was associated with greater blood burden but not poor clinical grade. Acute hydrocephalus occurs in one-quarter of NA-SAH patients. The greater risk in diffuse bleeding appears to be mediated by greater cisternal blood volume but not by greater ventriculomegaly. Imaging characteristics may aid in anticipatory management of hydrocephalus in NA-SAH.

Cerebellar GABAergic progenitors adopt an external granule cell-like phenotype in the absence of Ptf1a transcription factor expression.

PubMed

Pascual, Marta; Abasolo, Ibane; Mingorance-Le Meur, Ana; Martínez, Albert; Del Rio, José A; Wright, Christopher V E; Real, Francisco X; Soriano, Eduardo

2007-03-20

We report in this study that, in the cerebellum, the pancreatic transcription factor Ptf1a is required for the specific generation of Purkinje cells (PCs) and interneurons. Moreover, granule cell progenitors in the external GCL (EGL) appear to be unaffected by deletion of Ptf1a. Cell lineage analysis in Ptf1a(Cre/Cre) mice was used to establish that, in the absence of Ptf1a expression, ventricular zone progenitors, normally fated to produce PCs and interneurons, aberrantly migrate to the EGL and express typical markers of these cells, such as Math1, Reelin, and Zic1/2. Furthermore, these cells have a fine structure typical of EGL progenitors, indicating that they adopt an EGL-like cell phenotype. These findings indicate that Ptf1a is necessary for the specification and normal production of PCs and cerebellar interneurons. Moreover, our results suggest that Ptf1a is also required for the suppression of the granule cell specification program in cerebellar ventricular zone precursors.

Influence of pHo on calcium channel block by amlodipine, a charged dihydropyridine compound. Implications for location of the dihydropyridine receptor

PubMed Central

1989-01-01

We have investigated the modulation of L-type calcium channel currents in isolated ventricular cells by the dihydropyridine derivative amlodipine, a weak base with a pKa of 8.6. Under conditions that favor neutral drug molecules, amlodipine block resembles other, previously described, neutral dihydropyridine derivatives: block is more pronounced at depolarized voltages, repetitive pulsing is not needed to promote block, and recovery is complete at hyperpolarized voltages. When the drug is ionized, depolarized voltages still enhance block, however, the time course is slow and speeded by repetitive pulses that open channels. Recovery from block by ionized drug molecules is very slow and incomplete, but can be rapidly modified by changes in external hydrogen ion concentration. We conclude from these observations that the degree of ionization of the drug molecule can affect access to the dihydropyridine receptor and that external protons can interact with the drug-receptor complex even if channels are blocked and closed. These observations place limitations on the location of this receptor in the ventricular cell membrane. PMID:2549176

Effects of ventricular rate and regularity on the velocity and magnitude of left atrial appendage flow in atrial fibrillation

PubMed Central

Obel, O A; Luddington, L; Maarouf, N; Aytemir, K; Ekwall, C; Malik, M; Camm, A J

2005-01-01

Objective: To prospectively determine whether ventricular rate and regularity are significant determinants of the velocity and magnitude of left atrial appendage (LAA) flow. Design and patients: 12 patients with atrial fibrillation (AF), high degree atrioventricular block, and indwelling permanent pacemakers were studied. Setting: Cardiology department of a tertiary referral centre. Interventions: Pacing was triggered by an external programmable transcutaneous device. Patients were paced at 60, 120, and 150 beats/min in both regular and irregular rhythm. LAA flow velocity and magnitude were assessed with transoesophageal Doppler echocardiography. Main outcome measures: Peak and mean LAA inflow and outflow velocity, and time-velocity interval (TVI) of LAA flow. Results: Increasing ventricular rate was associated with significantly lower peak inflow (p < 0.01), peak outflow (p < 0.05), mean inflow (p < 0.01), and mean outflow (p < 0.05) velocities and with a lower TVI of LAA filling and emptying velocities (p < 0.01). This effect was noted at rates of 60 beats/min compared with both 120 and 150 beats/min. At a pacing rate of 120 beats/min there was a significantly higher total TVI when pacing at a regular than at an irregular rhythm (40.16 (14.6) cm v 30.74 (10.9) cm, p < 0.05). Conclusions: In this study, LAA filling velocities in patients in AF were significantly influenced by paced ventricular rate and to a much lesser extent ventricular rhythm. These results suggest that rapid ventricular rates may predispose to stasis in the LAA in AF. PMID:15894771

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.

Ventricular fibrillation occurring after atrioventricular node ablation despite minimal difference between pre- and post-ablation heart rates.

PubMed

Squara, F; Theodore, G; Scarlatti, D; Ferrari, E

2017-02-01

We report the case of an 82-year-old man presenting with ventricular fibrillation (VF) occurring acutely after atrioventricular node (AVN) ablation. This patient had severe valvular cardiomyopathy, chronic atrial fibrillation (AF), and underwent prior to the AVN ablation a biventricular implantable cardiac defibrillator positioning. The VF was successfully cardioverted with one external electrical shock. What makes this presentation original is that the pre-ablation spontaneous heart rate in AF was slow (84 bpm), and that VF occurred after ablation despite a minimal heart rate drop of only 14 bpm. VF is the most feared complication of AVN ablation, but it had previously only been described in case of acute heart rate drop after ablation of at least 30 bpm (and more frequently>50 bpm). This case report highlights the fact that VF may occur after AVN ablation regardless of the heart rate drop, rendering temporary fast ventricular pacing mandatory whatever the pre-ablation heart rate. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Aortic Wave Dynamics and Its Influence on Left Ventricular Workload

PubMed Central

Pahlevan, Niema M.; Gharib, Morteza

2011-01-01

The pumping mechanism of the heart is pulsatile, so the heart generates pulsatile flow that enters into the compliant aorta in the form of pressure and flow waves. We hypothesized that there exists a specific heart rate at which the external left ventricular (LV) power is minimized. To test this hypothesis, we used a computational model to explore the effects of heart rate (HR) and aortic rigidity on left ventricular (LV) power requirement. While both mean and pulsatile parts of the pressure play an important role in LV power requirement elevation, at higher rigidities the effect of pulsatility becomes more dominant. For any given aortic rigidity, there exists an optimum HR that minimizes the LV power requirement at a given cardiac output. The optimum HR shifts to higher values as the aorta becomes more rigid. To conclude, there is an optimum condition for aortic waves that minimizes the LV pulsatile load and consequently the total LV workload. PMID:21853075

Diastolic function of the nonfilling human left ventricle.

PubMed

Paulus, W J; Vantrimpont, P J; Rousseau, M F

1992-12-01

To investigate an early-diastolic left ventricular suction effect in humans, tip-micromanometer left ventricular pressure recordings were obtained in patients with mitral stenosis at the time of balloon inflations during percutaneous mitral valvuloplasty performed with a self-positioning Inoue balloon, which fits tightly in the mitral orifice. When mitral inflow was impeded in anesthetized dogs, left ventricular pressure decayed to a negative asymptote value. This negative asymptote value was consistent with an early diastolic suction effect. Tip-micromanometer left ventricular pressure recordings were obtained in 23 patients with symptomatic mitral stenosis at the time of balloon inflations during percutaneous mitral valvuloplasty performed with a self-positioning Inoue balloon. The left ventricular diastolic asymptote pressure (P(asy)) was determined in 47 nonfilling beats with a sufficiently long (greater than 200 ms) diastolic time interval (that is, the interval from minimal first derivative of left ventricular pressure to left ventricular end-diastolic pressure) and equaled 2 +/- 3 mm Hg for beats with normal intraventricular conduction and 3 +/- 2 mm Hg for beats with aberrant intraventricular conduction. Left ventricular angiography was performed in five patients during the first inflation of the Inoue balloon at the time of complete balloon expansion. Left ventricular end-diastolic volume of the nonfilling beats averaged 38 +/- 14 ml and was comparable to the left ventricular end-systolic volume (39 +/- 19 ml) measured during baseline angiography before mitral valvuloplasty. Time constants of left ventricular pressure decay were calculated on 21 nonfilling beats with a diastolic time interval greater than 200 ms, normal intraventricular conduction and peak left ventricular pressure greater than 50 mm Hg. Time constants (T0 and TBF) derived from an exponential curve fit with zero asymptote pressure and with a best-fit asymptote pressure were compared with a time constant (T(asy)) derived from an exponential curve fit with the measured diastolic left ventricular asymptote pressure. The value for T(asy) (37 +/- 9 ms) was significantly smaller than that for TBF (68 +/- 28 ms, p less than 0.001) and the value for the measured diastolic left ventricular asymptote pressure (2 +/- 4 mm Hg) was significantly larger than that for the best-fit asymptote pressure (-9 +/- 11 mm Hg, p less than 0.001). T0 (44 +/- 20 ms) was significantly (p less than 0.01) different from TBF but not from T(asy). During balloon inflation of a self-positioning Inoue balloon, left ventricular pressure decayed continuously toward a positive asymptote value and left ventricular cavity volume was comparable to the left ventricular end-systolic volume of filling beats. In these nonfilling beats, the best-fit asymptote pressure was unrelated to the measured asymptote pressure and T0 was a better measure of T(asy) than was TBF. Reduced internal myocardial restoring forces, caused by different extracellular matrix of the human heart, reduced external myocardial restoring forces caused by low coronary perfusion pressure during the balloon inflation and inward motion of the balloon-occluded mitral valve into the left ventricular cavity could explain the failure to observe significant diastolic left ventricular suction in the human heart.

Fabrication and characteristics of MOSFET protein chip for detection of ribosomal protein.

PubMed

Park, Keun-Yong; Kim, Min-Suk; Choi, Sie-Young

2005-04-15

A metal oxide silicon field effect transistor (MOSFET) protein chip for the easy detection of protein was fabricated and its characteristics were investigated. Generally, the drain current of the MOSFET is varied by the gate potential. It is expected that the formation of an antibody-antigen complex on the gate of MOSFET would lead to a detectable change in the charge distribution and thus, directly modulate the drain current of MOSFET. As such, the drain current of the MOSFET protein chip can be varied by ribosomal proteins absorbed by the self-assembled monolayer (SAM) immobilized on the gate (Au) surface, as ribosomal protein has positive charge, and these current variations then used as the response of the protein chip. The gate of MOSFET protein chip is not directly biased by an external voltage source, so called open gate or floating gate MOSFET, but rather chemically modified by immobilized molecular receptors called self-assembled monolayer (SAM). In our experiments, the current variation in the proposed protein chip was about 8% with a protein concentration of 0.7 mM. As the protein concentration increased, the drain current also gradually increased. In addition, there were some drift of the drain current in the device. It is considered that these drift might be caused by the drift from the MOSFET itself or protein absorption procedures that are relied on the facile attachment of thiol (-S) ligands to the gate (Au) surface. We verified the formation of SAM on the gold surface and the absorption of protein through the surface plasmon resonance (SPR) measurement.

Heat transfer in a tank with a cryogenic fluid under conditions of external heating

NASA Astrophysics Data System (ADS)

Notkin, V. L.

Heat transfer in the gas layer of a horizontal cylindrical tank with a fluctuating level of boiling liquid nitrogen is investigated experimentally. Criterial equations for heat transfer in the gas cavity of the tank are obtained. A procedure is proposed for calculating heat fluxes, temperature fields, and cryogenic fluid evaporation during the filling and draining of the tank.

Acute hemodynamic efficacy of a 32-ml subcutaneous counterpulsation device in a calf model of diminished cardiac function.

PubMed

Koenig, Steven C; Litwak, Kenneth N; Giridharan, Guruprasad A; Pantalos, George M; Dowling, Robert D; Prabhu, Sumanth D; Slaughter, Mark S; Sobieski, Michael A; Spence, Paul A

2008-01-01

The acute hemodynamic efficacy of an implantable counterpulsation device (CPD) was evaluated. The CPD is a valveless single port, 32-ml stroke volume blood chamber designed to be connected to the human axillary artery using a simple surface surgical procedure. Blood is drawn into the pump during systole and ejected during diastole. The acute hemodynamic effects of the 32-ml CPD were compared to a standard clinical 40-ml intra-aortic balloon pump (IABP) in calves (80 kg, n = 10). The calves were treated by a single oral dose of Monensin to produce a model of diminished cardiac function (DCF). The CPD and IABP produced similar increases in cardiac output (6% CPD vs. 5% IABP, p > 0.5) and reduction in left ventricular external work (14% CPD vs. 13% IABP, p > 0.5) compared to DCF (p < 0.05). However, the ratio of diastolic coronary artery flow to left ventricular external work increase from DCF baseline (p < 0.05) was greater with the CPD compared to the IABP (15% vs. 4%, p < 0.05). The CPD also produced a greater reduction in left ventricular myocardial oxygen consumption from DCF baseline (p < 0.05) compared to the IABP (13% vs. 9%, p < 0.05) despite each device providing similar improvements in cardiac output. There was no early indication of hemolysis, thrombus formation, or vascular injury. The CPD provides hemodynamic efficacy equivalent to an IABP and may become a therapeutic option for patients who may benefit from prolonged counterpulsation.

Acute Hemodynamic Efficacy of a 32-ml Subcutaneous Counterpulsation Device in a Calf Model of Diminished Cardiac Function

PubMed Central

Koenig, Steven C.; Litwak, Kenneth N.; Giridharan, Guruprasad A.; Pantalos, George M.; Dowling, Robert D.; Prabhu, Sumanth D.; Slaughter, Mark S.; Sobieski, Michael A.; Spence, Paul A.

2010-01-01

The acute hemodynamic efficacy of an implantable counter-pulsation device (CPD) was evaluated. The CPD is a valveless single port, 32-ml stroke volume blood chamber designed to be connected to the human axillary artery using a simple surface surgical procedure. Blood is drawn into the pump during systole and ejected during diastole. The acute hemodynamic effects of the 32-ml CPD were compared to a standard clinical 40-ml intra-aortic balloon pump (IABP) in calves (80 kg, n = 10). The calves were treated by a single oral dose of Monensin to produce a model of diminished cardiac function (DCF). The CPD and IABP produced similar increases in cardiac output (6% CPD vs. 5% IABP, p > 0.5) and reduction in left ventricular external work (14% CPD vs. 13% IABP, p > 0.5) compared to DCF (p < 0.05). However, the ratio of diastolic coronary artery flow to left ventricular external work increase from DCF baseline (p < 0.05) was greater with the CPD compared to the IABP (15% vs. 4%, p < 0.05). The CPD also produced a greater reduction in left ventricular myocardial oxygen consumption from DCF baseline (p < 0.05) compared to the IABP (13% vs. 9%, p < 0.05) despite each device providing similar improvements in cardiac output. There was no early indication of hemolysis, thrombus formation, or vascular injury. The CPD provides hemodynamic efficacy equivalent to an IABP and may become a therapeutic option for patients who may benefit from prolonged counterpulsation. PMID:19033769

Safety aspects for public access defibrillation using automated external defibrillators near high-voltage power lines.

PubMed

Schlimp, C J; Breiteneder, M; Lederer, W

2004-05-01

Automated external defibrillators (AEDs) must combine easy operability and high-quality diagnosis even under unfavorable conditions. This study determined the influence of electromagnetic interference caused by high-voltage power lines with 16.7-Hz alternating current on the quality of AEDs' rhythm analysis. Two AEDs frequently used in Austria were tested near high-voltage power lines (15 kV or 110 kV, alternating current with 16.7 Hz). The defibrillation electrodes were attached either to a proband with true sinus rhythm or to a resuscitation dummy with generated sinus rhythm, ventricular fibrillation, ventricular tachycardia or asystole. Electromagnetic interference was much more prominent in a human's than in a dummy's electrocardiogram and depended on the position of the electrodes and cables in relation to the power line. Near high-voltage power lines the AEDs showed a significant operational fault. One AED interpreted the interference as a motion artifact, even when underlying rhythms were clearly detectable. The other AED interpreted 16.7-Hz oscillation as ventricular fibrillation with consequent shock advice when no underlying rhythm was detected. The tested AEDs neither filter nor recognize a technical interference of 16.7 Hz caused by 15-kV power lines above railway tracks or 110-kV overland power lines, as run by railway companies in Austria, Germany, Norway, Sweden and Switzerland. These failures in AEDs' algorithms for rhythm analysis may cause substantial harm to patients undergoing public access defibrillation. The proper function of AEDs needs to be reconsidered to guarantee patients' safety near high-voltage power lines.

The Utility and Benefits of External Lumbar CSF Drainage after Endovascular Coiling on Aneurysmal Subarachnoid Hemorrhage

PubMed Central

Kwon, Ou Young; Kim, Young Jin; Cho, Chun Sung; Lee, Sang Koo; Cho, Maeng Ki

2008-01-01

Objective Cerebral vasospasm still remains a major cause of the morbidity and mortality, despite the developments in treatment of aneurysmal subarachnoid hemorrhage. The authors measured the utility and benefits of external lumbar cerebrospinal fluid (CSF) drainage to prevent the clinical vasospasm and its sequelae after endovascular coiling on aneurysmal subarachnoid hemorrhage in this randomized study. Methods Between January 2004 and March 2006, 280 patients with aneurysmal subarachnoid hemorrhage were treated at our institution. Among them, 107 patients met our study criteria. The treatment group consisted of 47 patients who underwent lumbar CSF drainage during vasospasm risk period (about for 14 days after SAH), whereas the control group consisted of 60 patients who received the management according to conventional protocol without lumbar CSF drainage. We created our new modified Fisher grade on the basis of initial brain computed tomography (CT) scan at admission. The authors established five outcome criteria as follows : 1) clinical vasospasm; 2) GOS score at 1-month to 6-month follow-up; 3) shunt procedures for hydrocephalus; 4) the duration of stay in the ICU and total hospital stay; 5) mortality rate. Results The incidence of clinical vasospasm in the lumbar drain group showed 23.4% compared with 63.3% of individuals in the control group. Moreover, the risk of death in the lumbar drain group showed 2.1% compared with 15% of individuals in the control group. Within individual modified Fisher grade, there were similar favorable results. Also, lumbar drain group had twice more patients than the control group in good GOS score of 5. However, there were no statistical significances in mean hospital stay and shunt procedures between the two groups. IVH was an important factor for delayed hydrocephalus regardless of lumbar drain. Conclusion Lumbar CSF drainage remains to play a prominent role to prevent clinical vasospasm and its sequelae after endovascular coiling on aneurysmal subarachnoid hemorrhage. Also, this technique shows favorable effects on numerous neurological outcomes and prognosis. The results of this study warrant clinical trials after endovascular treatment in patients with aneurysmal SAH. PMID:19096633

External lumbar cerebrospinal fluid drainage in patients with aneurysmal subarachnoid hemorrhage: A systematic review and meta-analysis of controlled trials.

PubMed

Alcalá-Cerra, G; Paternina-Caicedo, Á; Díaz-Becerra, C; Moscote-Salazar, L R; Gutiérrez-Paternina, J J; Niño-Hernández, L M

2016-09-01

External lumbar drainage is a promising measure for the prevention of delayed aneurysmal subarachnoid hemorrhage-related ischemic complications. Controlled studies evaluating the effects of external lumbar drainage in patients with aneurysmal subarachnoid hemorrhage were included. Primary outcomes were: new cerebral infarctions and severe disability. Secondary outcomes were: clinical deterioration due to delayed cerebral ischemia, mortality, and the need of definitive ventricular shunting. Results were presented as pooled relative risks, with their 95% confidence intervals (95% CI). A total of 6 controlled studies were included. Pooled relative risks were: new cerebral infarctions, 0.48 (95% CI: 0.32-0.72); severe disability, 0.5 (95% CI: 0.29-0.85); delayed cerebral ischemia-related clinical deterioration, 0.46 (95% CI: 0.34-0.63); mortality, 0.71 (95% CI: 0.24-2.06), and need of definitive ventricular shunting, 0.80 (95% CI: 0.51-1.24). Assessment of heterogeneity only revealed statistically significant indexes for the analysis of severe disability (I(2)=70% and P=.01). External lumbar drainage was associated with a statistically significant decrease in the risk of delayed cerebral ischemia-related complications (cerebral infarctions and clinical deterioration), as well as the risk of severe disability; however, it was not translated in a lower mortality. Nevertheless, it is not prudent to provide definitive recommendations at this time because of the qualitative and quantitative heterogeneity among included studies. More randomized controlled trials with more homogeneous outcomes and definitions are needed to clarify its impact in patients with aneurysmal subarachnoid hemorrhage. Copyright © 2013 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

External prolonged electrocardiogram monitoring in unexplained syncope and palpitations: results of the SYNARR-Flash study.

PubMed

Locati, E T; Moya, A; Oliveira, M; Tanner, H; Willems, R; Lunati, M; Brignole, M

2016-08-01

SYNARR-Flash study (Monitoring of SYNcopes and/or sustained palpitations of suspected ARRhythmic origin) is an international, multicentre, observational, prospective trial designed to evaluate the role of external 4-week electrocardiogram (ECG) monitoring in clinical work-up of unexplained syncope and/or sustained palpitations of suspected arrhythmic origin. Consecutive patients were enrolled within 1 month after unexplained syncope or palpitations (index event) after being discharged from emergency room or hospitalization without a conclusive diagnosis. A 4-week ECG monitoring was obtained by external high-capacity loop recorder (SpiderFlash-T(®), Sorin) storing patient-activated and auto-triggered tracings. Diagnostic monitorings included (i) conclusive events with reoccurrence of syncope or palpitation with concomitant ECG recording (with/without arrhythmias) and (ii) events with asymptomatic predefined significant arrhythmias (sustained supraventricular or ventricular tachycardia, advanced atrio-ventricular block, sinus bradycardia <30 b.p.m., pauses >6 s). SYNARR-Flash study enrolled 395 patients (57.7% females, 56.9 ± 18.7 years, 28.1% with syncope, and 71.9% with palpitations) from 10 European centres. For syncope, the 4-week diagnostic yield was 24.5%, and predictors of diagnostic events were early start of recording (0-15 vs. >15 days after index event) (OR 6.2, 95% CI 1.3-29.6, P = 0.021) and previous history of supraventricular arrhythmias (OR 3.6, 95% CI 1.4-9.7, P = 0.018). For palpitations, the 4-week diagnostic yield was 71.6% and predictors of diagnostic events were history of recurrent palpitations (P < 0.001) and early start of recording (P = 0.001). The 4-week external ECG monitoring can be considered as first-line tool in the diagnostic work-up of syncope and palpitation. Early recorder use, history of supraventricular arrhythmia, and frequent previous events increased the likelihood of diagnostic events during the 4-week external ECG monitoring. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

Ascending transaqueductal cystoventriculoperitoneal shunting in Dandy-Walker malformation: technical note.

PubMed

Unal, Omer Faruk; Aras, Yavuz; Aydoseli, Aydin; Akcakaya, Mehmet Osman

2012-01-01

The optimal treatment for Dandy-Walker malformation is still controversial. Ventriculoperitoneal shunting, cystoperitoneal shunting or combinations are the most common surgical options in the management of this clinical entity. Endoscopic procedures like ventriculocystostomy, 3rd ventriculostomy or endoscopy-assisted shunt surgeries have become the focus of recent publications. We describe a new transcystic endoscopic technique, with the usage of a single ascending transaqueductal shunt catheter with additional holes, whereby both the posterior fossa cyst and supratentorial ventricular compartments are drained effectively. By using this new technique complications associated with combined shunting can be avoided. In addition, by equalizing the pressure within the supra- and infratentorial compartments, the upward or downward herniations associated with single-catheter shunting can be prevented. Copyright © 2013 S. Karger AG, Basel.

Limb salvage in Charcot foot and ankle osteomyelitis: combined use single stage/double stage of arthrodesis and external fixation.

PubMed

Dalla Paola, Luca; Brocco, Enrico; Ceccacci, Tanja; Ninkovic, Sasa; Sorgentone, Sara; Marinescu, Maria Grazia; Volpe, Antonio

2009-11-01

Charcot neuroarthropathy of the foot/ankle is a devastating complication of diabetes. Along with neuroarthropathy, osteomyelitis can occur which can result in amputation. This prospective study evaluated a limb salvage procedure as an alternative to amputation through surgical treatment of osteomyelitis of the midfoot or the ankle and stabilization with external fixation. Forty-five patients with Charcot arthropathy and osteomyelitis underwent debridement and attempted fusion with an external fixator. Chart and radiograph review was performed to assess the success of the fusion and eradication of infection. Out of 45 patients, 39 patients healed using emergent surgery to drain an acute manifestation of the infection while maintaining the fixation for an average of 25.7 weeks. Two patients were treated with intramedullary nail in a subsequent surgical procedure. In four patients, the infection could not be controlled, therefore a major amputation was carried out. For select patients, external fixation proved to be a reasonable alternative to below-knee amputation.

Endoscopic Third Ventriculostomy before Posterior Fossa Tumor Surgery in Adult Patients.

PubMed

Marx, Sascha; El Damaty, Ahmed; Manwaring, Jotham; El Refaee, Ehab; Fleck, Steffen; Fritsch, Michael; Gaab, Michael R; Schroeder, H W S; Baldauf, Jörg

2018-03-01

 Obstructive hydrocephalus in patients with posterior fossa tumors is frequently seen. Treatment options include immediate tumor removal or prior cerebrospinal fluid (CSF) diversion procedures. The necessity and feasibility of an ETV in these situations has not yet been proven in adult patients.  We retrospectively reviewed our prospectively maintained database for ETVs before surgery of posterior fossa tumors in adults. The primary focus of data analyses was the question of whether the ETV was suitable to treat the acute situation of hydrocephalus without an increased rate of complications due to the special anatomical situation with a posterior fossa tumor. We also analyzed whether any further CSF diverting procedures were necessary.  A total of 40 adult patients who underwent an ETV before posterior fossa tumor surgery were analyzed. Overall, 33 patients (82.5%) had clinical signs of hydrocephalus, and all of them improved in their clinical course after ETV. Seven patients (17.5%) did not demonstrate clinical signs of hydrocephalus, but ETV was performed with prophylactic or palliative intent in six patients and one patient, respectively. No complications were observed due to ETV itself. No permanent shunting procedure was necessary in a mean follow-up of 76.5 months. Early additional CSF diverting procedures (redo ETV, external ventricular drain) were performed in five patients (12.5%).  The present series confirms the feasibility and safety of ETV before posterior fossa tumor surgery in adult patients. If patients had symptomatic hydrocephalus before tumor surgery, an ETV can be performed, followed by early elective tumor surgery. A prophylactic ETV in asymptomatic patients is not advised. Early elective tumor surgery should be performed in these patients. Georg Thieme Verlag KG Stuttgart · New York.

Intracranial pressure monitoring after primary decompressive craniectomy in traumatic brain injury: a clinical study.

PubMed

Picetti, Edoardo; Caspani, Maria Luisa; Iaccarino, Corrado; Pastorello, Giulia; Salsi, Pierpaolo; Viaroli, Edoardo; Servadei, Franco

2017-04-01

Intracranial pressure (ICP) monitoring represents an important tool in the management of traumatic brain injury (TBI). Although current information exists regarding ICP monitoring in secondary decompressive craniectomy (DC), little is known after primary DC following emergency hematoma evacuation. Retrospective analysis of prospectively collected data. Inclusion criteria were age ≥18 years and admission to the intensive care unit (ICU) for TBI and ICP monitoring after primary DC. Exclusion criteria were ICU length of stay (LOS) <1 day and pregnancy. Major objectives were: (1) to analyze changes in ICP/cerebral perfusion pressure (CPP) after primary DC, (2) to evaluate the relationship between ICP/CPP and neurological outcome and (3) to characterize and evaluate ICP-driven therapies after DC. A total of 34 patients were enrolled. Over 308 days of ICP/CPP monitoring, 130 days with at least one episode of intracranial hypertension (26 patients, 76.5%) and 57 days with at least one episode of CPP <60 mmHg (22 patients, 64.7%) were recorded. A statistically significant relationship was discovered between the Glasgow Outcome Scale (GOS) scores and mean post-decompression ICP (p < 0.04) and between GOS and CPP minimum (CPPmin) (p < 0.04). After DC, persisting intracranial hypertension was treated with: barbiturate coma (n = 7, 20.6%), external ventricular drain (EVD) (n = 4, 11.8%), DC diameter widening (n = 1, 2.9%) and removal of newly formed hematomas (n = 3, 8.8%). Intracranial hypertension and/or low CPP occurs frequently after primary DC; their occurence is associated with an unfavorable neurological outcome. ICP monitoring appears useful in guiding therapy after primary DC.

Very Large Metastases to the Brain: Retrospective Study on Outcomes of Surgical Management.

PubMed

Gattozzi, Domenico A; Alvarado, Anthony; Kitzerow, Collin; Funkhouser, Alexander; Bimali, Milan; Moqbel, Murad; Chamoun, Roukoz B

2018-05-25

The incidence of brain metastases is rising. No published study focuses exclusively on brain metastases larger than 4 cm. We present our surgical outcomes for patients with brain metastases larger than 4 cm. This is a retrospective chart review of inpatient data at our institution from January 2006 to September 2015. Primary endpoints included overall survival, progression-free survival, and local recurrence rate. Sixty-one patients had a total of 67 brain metastases larger than 4 cm: 52 supratentorial and 15 infratentorial. Forty-three patients underwent surgical resection. Average duration of disease freedom after resection was 4.79 months (range 0-30). Excluding patients with residual on immediate post-operative MRI, average rate of local recurrence was 7 months (range 1-14). Overall survival after surgery excluding patients who chose palliation in the immediate postoperative period averaged 8.76 months (range 1-37). Thirty-five (81.4%) of 43 patients had stable or improved neurological exams post-operatively. Six (13.95%) patients developed surgical complications. There were 3 (6.98%) major complications: 2 pseudomeningoceles requiring intervention, and 1 post-operative hematoma requiring external ventricular drain placement. There were 3 (6.98%) minor complications: 1 self-limited pseudomeningocele, 1 subgaleal fluid collection, and 1 post-operative seizure. Surgery resulted in stable or improved neurological exam in 81.4% of cases. On statistical analysis, significantly increased overall survival was noted in patients undergoing surgical resection, as well as those with higher KPS and lower number of brain metastases at presentation. There is need for further studies to evaluate management of brain metastases larger than 4 cm. Copyright © 2018 Elsevier Inc. All rights reserved.

Differences in Neuropeptide Y Secretion Between Intracerebral Hemorrhage and Aneurysmal Subarachnoid Hemorrhage.

PubMed

Schebesch, Karl-M; Bründl, Elisabeth; Schödel, Petra; Hochreiter, Andreas; Scheitzach, Judith; Bele, Sylvia; Brawanski, Alexander; Störr, Eva-M; Lohmeier, Anette; Proescholdt, Martin

2017-07-01

Neuropeptide Y (NPY) is one of the most potent endogenous vasoconstrictors, and its contribution to the multifactorial cascade of cerebral vasospasm due to nontraumatic subarachnoid hemorrhage (SAH) is not yet fully understood. This experimental study compared the hemorrhage-specific course of NPY secretion into cerebrospinal fluid (CSF) and into plasma between 2 groups: patients with SAH and patients with basal ganglia hemorrhage (BGH) or cerebellar hemorrhage (CH) over the first 10 days after hemorrhage. Seventy-nine patients were prospectively included: SAH patients (n=66) (historic population) and intracerebral hemorrhage patients (n=13). All patients received an external ventricular drain within 24 hours of the onset of bleeding. CSF and plasma were drawn daily from day 1 to day 10. The levels of NPY were determined by means of competitive enzyme immunoassay. The CSF samples of 29 patients (historic population) who had undergone spinal anesthesia due to orthopedic surgery served as the control group. NPY levels in CSF were significantly higher in the 2 hemorrhage groups than in the control group. However, the 2 hemorrhage groups showed significant differences in NPY levels in CSF (SAH mean, 0.842 ng/mL vs. BGH/CH mean, 0.250 ng/mL; P<0.001) as well as in the course of NPY secretion into CSF over the 10-day period. NPY levels in plasma did not differ significantly among SAH, BGH/CH, and controls. Our findings support the hypothesis that excessive release of NPY into CSF but not into plasma is specific to aneurysmal SAH in the acute period of 10 days after hemorrhage. In BGH/CH, CSF levels of NPY were also increased, but the range was much lower.

Factors Associated with Fever in Intracerebral Hemorrhage.

PubMed

Gillow, Sabreena J; Ouyang, Bichun; Lee, Vivien H; John, Sayona

2017-06-01

Fever is common in patients with intracerebral hemorrhage (ICH). We sought to identify predictors of fever in patients hospitalized with ICH, and compare infectious fever with noninfectious fever. A retrospective review on consecutive spontaneous ICH patients from April 2009 to March 2010 was performed. Fever was defined as temperature 100.9°F or higher and attributed to infectious versus noninfectious etiology, based upon the National Healthcare Safety Network criteria. Univariate analysis and multivariable logistic regression model were used to determine factors associated with fever and with infection. Among the 351 ICH patients, 136 (39%) developed fever. Factors associated with fever included mean ICH volume, intraventricular hemorrhage (IVH), external ventricular drain (EVD) placement or surgical evacuation, positive microbial cultures, longer length of stay (LOS), and higher in-hospital mortality. Among patients with fever, 96 (71%) were noninfectious and 40 (29%) were infectious. Infectious fever was associated with higher LOS. Noninfectious fever was associated with higher in-hospital mortality. In multivariable analysis, ICH volume (OR = 1.01, P = .04), IVH (OR = 2.0, P = .03), EVD (OR = 3.7, P < .0001), and surgical evacuation (OR = 6.78, P < .0001) were significant predictors of fever. Infectious fever (OR = 5.26, P = .004), EVD (OR = 4.86, P = .01), and surgical evacuation (OR = 4.77, P = .04) correlated with prolonged LOS when dichotomized using a median of 15 days. Fever is common in ICH patients and is not associated with a clear infectious etiology in the majority of patients. Patients with noninfectious fever have higher in-hospital mortality, but survivors have shorter LOS. Further studies are warranted to better understand fevers in ICH. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Minimally invasive evacuation of intraventricular hemorrhage with the Apollo vibration/suction device.

PubMed

Tan, Lee A; Lopes, Demetrius K; Munoz, Lorenzo F; Shah, Yojan; Bhabad, Sudeep; Jhaveri, Miral; Moftakhar, Roham

2016-05-01

Intraventricular hemorrhages (IVH) can occur as a consequence of spontaneous intracerebral hemorrhage, aneurysm rupture, arteriovenous malformation hemorrhage, trauma, or coagulopathy. IVH is a known risk factor for poor clinical outcome with up to 80% mortality. The current standard treatment strategy for IVH consists of the placement of an external ventricular drain. We report our early experience with using the Apollo suction/vibration aspiration system (Penumbra, Alameda, CA, USA) for minimally invasive evacuation of IVH with a review of the pertinent literature. Medical records of patients with IVH who were admitted to Rush University Medical Center, USA, from July to November 2014 were queried from the electronic database. Patients with Graeb Scores (GS) >6 were selected for minimally invasive IVH evacuation with the Apollo aspiration system. Patient demographics, pre- and post-operative GS, pre- and post-operative modified Graeb Score (mGS), as well procedure related complications were analyzed and recorded. A total of eight patients (five men) were identified during the study period. The average age was 55.5years. The mean GS was 9.6 pre-operatively and decreased to 4.9 post-operatively (p=0.0002). The mean mGS was 22.9 pre-operatively and decreased to 11.4 post-operatively (p=0.0001). Most of the IVH reduction occurred in the frontal horn and atrium of the lateral ventricle, as well the third ventricle. One (1/8) procedure-related complication occurred consisted of a tract hemorrhage. The Apollo system can be used for minimally invasive IVH evacuation to achieve significant blood clot volume reduction with minimal procedure-related complication. Copyright © 2016. Published by Elsevier Ltd.

Clinical, biological, and microbiological pattern associated with ventriculostomy-related infection: a retrospective longitudinal study.

PubMed

Mounier, Roman; Lobo, David; Cook, Fabrice; Fratani, Alexandre; Attias, Arie; Martin, Mathieu; Chedevergne, Karin; Bardon, Jean; Tazi, Sanaa; Nebbad, Biba; Bloc, Sébastien; Plaud, Benoît; Dhonneur, Gilles

2015-12-01

Our aim was to describe the pattern of ventriculostomy-related infection (VRI) development using a dynamic approach. Retrospective longitudinal study. We analyzed the files of 449 neurosurgical patients who underwent placement of external ventricular drain (EVD). During the study period, CSF sampling was performed on a daily base setting. VRI was defined as a positive CSF culture resulting in antibiotic treatment. For VRI patients, we arbitrary defined day 0 (D0) as the day antibiotic treatment was started. In these patients, we compared dynamic changes in clinical and biological parameters at four pre-determined time points: (D-4, D-3, D-2, D-1) with those of D0. For all CSF-positive cultures, we compared CSF biochemical markers' evolution pattern between VRI patients and the others, considered as a control cohort. Thirty-two suffered from VRI. Peripheral white blood cell count did not differ between D-4-D0. Median body temperature, CSF cell count, median Glasgow Coma Scale, CSF protein, and glucose concentrations were significantly different between D-4, D-3, D-2, and D0. At D0, 100 % of CSF samples yielded organisms in culture. The physician caring for the patient decided to treat VRI based upon positive CSF culture in only 28 % (9/32) of cases. In the control cohort, CSF markers' profile trends to normalize, while it worsens in the VRI patients. We showed that clinical symptoms and biological abnormalities of VRI evolved over time. Our data suggest that VRI decision to treat relies upon a bundle of evidence, including dynamic changes in CSF laboratory exams combined with microbiological analysis.

Acute triventricular hydrocephalus caused by choroid plexus cysts: a diagnostic and neurosurgical challenge.

PubMed

Spennato, Pietro; Chiaramonte, Carmela; Cicala, Domenico; Donofrio, Vittoria; Barbarisi, Manlio; Nastro, Anna; Mirone, Giuseppe; Trischitta, Vincenzo; Cinalli, Giuseppe

2016-11-01

OBJECTIVE Intraventricular choroid plexus cysts are unusual causes of acute hydrocephalus in children. Radiological diagnosis of intraventricular choroid plexus cysts is difficult because they have very thin walls and fluid contents similar to CSF and can go undetected on routine CT studies. METHODS This study reports the authors' experience with 5 patients affected by intraventricular cysts originating from the choroid plexus. All patients experienced acute presentation with rapid neurological deterioration, sometimes associated with hypothalamic dysfunction, and required urgent surgery. In 2 cases the symptoms were intermittent, with spontaneous remission and sudden clinical deteriorations, reflecting an intermittent obstruction of the CSF pathway. RESULTS Radiological diagnosis was difficult in these cases because a nonenhanced CT scan revealed only triventricular hydrocephalus, with slight lateral ventricle asymmetry in all cases. MRI with driven-equilibrium sequences and CT ventriculography (in 1 case) allowed the authors to accurately diagnose the intraventricular cysts that typically occupied the posterior part of the third ventricle, occluding the aqueduct and at least 1 foramen of Monro. The patients were managed by urgent implantation of an external ventricular drain in 1 case (followed by endoscopic surgery, after completing a diagnostic workup) and by urgent endoscopic surgery in 4 cases. Endoscopic surgery allowed the shrinkage and near-complete removal of the cysts in all cases. Use of neuronavigation and a laser were indispensable. All procedures were uneventful, resulting in restoration of normal neurological conditions. Long-term follow-up (> 2 years) was available for 2 patients, and no complications or recurrences occurred. CONCLUSIONS This case series emphasizes the necessity of an accurate and precise identification of the possible causes of triventricular hydrocephalus. Endoscopic surgery can be considered the ideal treatment of choroid plexus cysts in children.

Air Force Operational Medicine: Using the Enterprise Estimating Supplies Program to Develop Materiel Solutions for the Medical Neurosurgical Team (FFNEU)

DTIC Science & Technology

2010-11-18

6515014978131 CRANIOTOMY -LAMINECTOMY CUSTOM PK FOR NEUROSURG MMS & CSG DEPMEP 30 30 105.00 7.50 17,131.80 105.00 7.50 17,131.80 D 6515003225550 CURETTE MASTOID...6515NCM040995 ASPEN CERVICAL COLLAR ADU 10 1 0.00 0.00 1,250.00 0.00 0.00 125.00 C 6515014687080 BAG DRAINAGE VENTRICULAR USED W/EXTERNAL DRAINAGE SYSTEM 5S 3...EESP cost A 6515013587147 DRAINAGE UNIT EXTERNAL 75ML DRIP CHAMBER W/ANTI REFLUX VALVE 2 2 4.00 0.80 388.80 4.00 0.80 388.80 B 6515015497613 DURAL

Haemodynamic and energetic properties of stunned myocardium in rabbit hearts.

PubMed Central

Schipke, J. D.; Korbmacher, B.; Dorszewski, A.; Selcan, G.; Sunderdiek, U.; Arnold, G.

1996-01-01

OBJECTIVE--To amplify the description of myocardial stunning. DESIGN--Control versus 30 min after a 20 min no flow ischaemia. EXPERIMENTAL ANIMALS--15 isolated rabbit hearts perfused with erythrocyte suspension. MAIN OUTCOME MEASURES--Left ventricular systolic function in terms of aortic flow, peak systolic pressure (LVPmax), dP/dtmax, and the end systolic pressure-volume relation (ESPVR); early relaxation from dP/dtmin and rate of left ventricular pressure decay (tau). Passive properties: ventricular and myocardial stiffness. Coronary resistance from coronary blood flow and perfusion pressure. Total myocardial oxygen consumption (MVo2tot). Total mechanical energy via pressure-volume area (PVA). Contractile efficiency (Econ) and MVo2 of the unloaded contracting heart (MVo2unl). External mechanical efficiency (Eext) from stroke work and MVo2tot. RESULTS--Systolic variables in stunned myocardium were significantly decreased (mean (SD)): aortic flow: 38 (13) v 9 (11) ml/min; LVPmax: 112 (19) v 74 (18) mm Hg; dP/dtmax: 1475 (400) v 1075 (275) mm Hg/s. ESPVR was not significantly decreased, at 138 (73) v 125 (58) mm Hg/ml, but the volume axis intercept was shifted rightward: 0.30 (0.37) v 0.65 (0.25) ml. Likewise, early relaxation was impaired: dP/dtmin (-1275 (250) v -975 (250) mm Hg/s) and tau (37 (7) v 46 (10) ms). LVPed was significantly decreased at 19 (12) v 12 (7) mm Hg, and both the ventricular (end diastolic pressure-volume relation) and the myocardial stiffness (constant k) were increased by 75% and 31%, respectively. Coronary resistance increased non-significantly from 0.83 (0.31) to 1.04 (0.41) mm Hg/(ml/min/100 g). Decreases in PVA (570 (280) v 270 (200) mm Hg.ml/100 g), MVo2tot (40 (9) v 34 (8) microliters/beat/100 g), and MVo2unl (26 (9) v 22 (6) microliters/beat/100 g) did not reach significance, in contrast to significant decreases in Econ (31 (18) v 14 (7)%) and Eext (0.75 (0.29) v 0.18 (0.25) arbitrary units). CONCLUSIONS--Ventricular systolic function is decreased after brief episodes of ischaemia. The decrease in diastolic function probably amplifies the systolic deterioration during myocardial stunning. Passive diastolic properties are also changed, shown by increases in both ventricular and myocardial stiffness. The increase in coronary resistance indicates stunning at the vascular level which could limit oxygen supply. With maintained MVo2tot during stunning, external efficiency is decreased. Possible candidates for this metabolic stunning are inadequate excitation-contraction coupling and disturbed O2 utilisation by the contractile apparatus. Images PMID:8624873

Evaluation of a Unique Defibrillation Unit with Dual-Vector Biphasic Waveform Capabilities: Towards a Miniaturized Defibrillator.

PubMed

Okamura, Hideo; Desimone, Christopher V; Killu, Ammar M; Gilles, Emily J; Tri, Jason; Asirvatham, Roshini; Ladewig, Dejae J; Suddendorf, Scott H; Powers, Joanne M; Wood-Wentz, Christina M; Gray, Peter D; Raymond, Douglas M; Savage, Shelley J; Savage, Walter T; Bruce, Charles J; Asirvatham, Samuel J; Friedman, Paul A

2017-02-01

Automated external defibrillators can provide life-saving therapies to treat ventricular fibrillation. We developed a prototype unit that can deliver a unique shock waveform produced by four independent capacitors that is delivered through two shock vectors, with the rationale of providing more robust shock pathways during emergent defibrillation. We describe the initial testing and feasibility of this unique defibrillation unit, features of which may enable downsizing of current defibrillator devices. We tested our defibrillation unit in four large animal models (two canine and two swine) under general anesthesia. Experimental defibrillation thresholds (DFT) were obtained by delivery of a unique waveform shock pulse via a dual-vector pathway with four defibrillation pads (placed across the chest). DFTs were measured and compared with those of a commercially available biphasic defibrillator (Zoll M series, Zoll Medical, Chelmsford, MA, USA) tested in two different vectors. Shocks were delivered after 10 seconds of stable ventricular fibrillation and the output characteristics and shock outcome recorded. Each defibrillation series used a step-down to failure protocol to define the defibrillation threshold. A total of 96 shocks were delivered during ventricular fibrillation in four large animals. In comparison to the Zoll M series, which delivered a single-vector, biphasic shock, the energy required for successful defibrillation using the unique dual-vector biphasic waveform did not differ significantly (P = 0.65). Our early findings support the feasibility of a unique external defibrillation unit using a dual-vector biphasic waveform approach. This warrants further study to leverage this unique concept and work toward a miniaturized, portable shock delivery system. © 2016 Wiley Periodicals, Inc.

Survival After Ventricular Fibrillation Cardiac Arrest in the Sao Paulo Metropolitan Subway System: First Successful Targeted Automated External Defibrillator (AED) Program in Latin America.

PubMed

Gianotto-Oliveira, Renan; Gonzalez, Maria Margarita; Vianna, Caio Brito; Monteiro Alves, Maurício; Timerman, Sergio; Kalil Filho, Roberto; Kern, Karl B

2015-10-09

Targeted automated external defibrillator (AED) programs have improved survival rates among patients who have an out-of-hospital cardiac arrest (OHCA) in US airports, as well as European and Japanese railways. The Sao Paulo (Brazil) Metro subway carries 4.5 million people per day. A targeted AED program was begun in the Sao Paulo Metro with the objective to improve survival from cardiac arrest. A prospective, longitudinal, observational study of all cardiac arrests in the Sao Paulo Metro was performed from September 2006 through November 2012. This study focused on cardiac arrest by ventricular arrhythmias, and the primary endpoint was survival to hospital discharge with minimal neurological impairment. A total of 62 patients had an initial cardiac rhythm of ventricular fibrillation. Because no data on cardiac arrest treatment or outcomes existed before beginning this project, the first 16 months of the implementation was used as the initial experience and compared with the subsequent 5 years of full operation. Return of spontaneous circulation was not different between the initial 16 months and the subsequent 5 years (6 of 8 [75%] vs. 39 of 54 [72%]; P=0.88). However, survival to discharge was significantly different once the full program was instituted (0 of 8 vs. 23 of 54 [43%]; P=0.001). Implementation of a targeted AED program in the Sao Paulo Metro subway system saved lives. A short interval between arrest and defibrillation was key for good long-term, neurologically intact survival. These results support strategic expansion of targeted AED programs in other large Latin American cities. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Chemotherapy administration directly into the fourth ventricle in a nonhuman primate model.

PubMed

Sandberg, David I; Peet, M Melissa; Johnson, Mark D; Cole, Phaedra; Koru-Sengul, Tulay; Luqman, Ali W

2012-05-01

The authors hypothesized that chemotherapy infusions directly into the fourth ventricle might potentially play a role in treating malignant fourth ventricular tumors. The study tested the safety and pharmacokinetics of short- and long-term infusions of methotrexate into the fourth ventricle in a new nonhuman primate model. Six rhesus monkeys underwent posterior fossa craniectomy and catheter insertion into the fourth ventricle. In Group I (3 animals), catheters were externalized, and lumbar drain catheters were placed simultaneously to assess CSF distribution after short-term methotrexate infusions. In 2 animals, methotrexate (0.5 mg) was infused into the fourth ventricle daily for 5 days. Serial CSF and serum methotrexate levels were measured. The third animal had a postoperative neurological deficit, and the experiment was aborted prior to methotrexate administration. In Group II (3 animals), catheters were connected to a subcutaneously placed port for subsequent long-term methotrexate infusions. In 2 animals, 4 cycles of intraventricular methotrexate, each consisting of 4 daily infusions (0.5 mg), were administered over 8 weeks. The third animal received 3 cycles, and then the experiment was terminated due to self-inflicted wound breakdown. All animals underwent detailed neurological evaluations, MRI, and postmortem histological analysis. No neurological deficits were noted after intraventricular methotrexate infusions. Magnetic resonance images demonstrated catheter placement within the fourth ventricle and no signal changes in the brainstem or cerebellum. Histologically, two Group I animals, one of which did not receive methotrexate, had several small focal areas of brainstem injury. Two Group II animals had a small (≤ 1-mm) focus of axonal degeneration in the midbrain. Intraventricular and meningeal inflammation was noted in 4 animals after methotrexate infusions (one from Group I and all three from Group II). In all Group II animals, inflammation extended minimally into brainstem parenchyma. Serum methotrexate levels were undetectable or negligible in both groups, ranging from 0.00 to 0.06 μmol/L. In Group I, the mean peak methotrexate level in fourth ventricle CSF exceeded that in the lumbar CSF by greater than 10-fold. Statistically significant differences between fourth ventricle and lumbar AUC (area under the concentration-time curve) were detected at peaks (p = 0.04) but not at troughs (p = 0.50) or at all time collection points (p = 0.12). In Group II, peak fourth ventricle CSF methotrexate levels ranged from 84.62 to 167.89 μmol/L (mean 115.53 ± 15.95 μmol/L [SD]). Trough levels ranged from 0.06 to 0.55 μmol/L (mean 0.22 ± 0.13 μmol/L). Methotrexate can be infused into the fourth ventricle in nonhuman primates without clinical or radiographic evidence of injury. Observed inflammatory and other histological changes had no clinical correlate. This approach may have pharmacokinetic advantages over current treatment paradigms. Further experiments are warranted to determine if fourth ventricular chemotherapy infusions may benefit patients with malignant fourth ventricular tumors.

[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.

[Phaeochromocytoma as an unusual aetiology of cardiogenic shock].

PubMed

Ouchikhe, A; Lehoux, P; Gringore, A; Renouf, P; Deredec, R; Tasle, M; Massetti, M; Khayat, A; Saloux, E; Grollier, G; Samama, G; Gérard, J-L

2006-01-01

The authors reported a case involving a young patient with a cardiogenic shock associated to an acute pulmonary oedema. According to the seriousness of the shock, an external ventricular assist device (VAD) was initially inserted and replaced thereafter because of the cardiovascular instability, by an external pneumatic biventricular assist device. A cardiogenic shock induced by an acute adrenergic myocarditis due to a phaeochromocytoma was diagnosed. The patient was weaned from the VAD on day 84 and was scheduled for elective surgery of the phaeochromocytoma on day 93. The authors discussed the time of the surgery according to the anticoagulation therapy necessary to the VAD and the necessary caution taken if a cardiogenic shock appeared around surgery.

Acknowledging the Elephant in the Room: How Stressful Environmental Contexts Shape Relationship Dynamics

PubMed Central

Neff, Lisa A.; Karney, Benjamin R.

2016-01-01

Compared to affluent marriages, lower income marriages develop within a context filled with negative stressors that may prove quite toxic for marital stability. The current paper argues that stressful contexts may undermine marital well-being through two routes. First, external stressors create additional problems within the marriage by diverting time and attention away from activities that promote intimacy between partners. Second, external stress may render spouses ill-equipped to cope with this increase in problems by draining spouses of the energy and resources necessary for responding to marital challenges in a constructive manner. In acknowledging the role of the marital context for relationship dynamics, this model suggests new directions for interventions designed to strengthen the marriages of lower income couples. PMID:27766285

Life-saving automated external defibrillation in a teenager: a case report

PubMed Central

Rey, Corsino; Rodríguez-Nuñez, Antonio; Medina, Alberto; Mayordomo, Juan

2007-01-01

Background Adolescent sudden death during sport participation is commonly due to cardiac causes. Survival is more likely when an automated external defibrillator (AED) is used soon after collapse. Case presentation We describe a case of sudden death in a 14 year old boy with two remarkable points, successful resuscitation at school using an AED and diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC). Bystander cardiopulmonary resuscitation (CPR) was immediately started by a witness and 5 minutes after the event the child was placed on an AED monitor that determined he was in a non shockable rhythm, therefore CPR was continued. Two minutes later, the AED monitor detected a shockable rhythm and recommended a shock, which was then administered. One minute after the shock, a palpable pulse was detected and the child began to breathe by himself. Four days after cardiac arrest, the boy was conversing and self-caring. Cardiac magnetic resonance imaging was suggestive of ARVC. Conclusion Ventricular fibrillation secondary to ARVC may be a devastating event and places young patients and athletes at high risk of sudden death. Immediate CPR and AED have been demonstrated to be lifesaving in such events. Therefore, we suggest that schools should have teachers skilled in CPR and accessible AEDs. PMID:17767706

Rapid Pore Cranial Drilling With External Ventricular Drainage for Treatment of Intraventricular Hemorrhage: A 36-Year Case Series

PubMed Central

Zhang, Wei; Wei, Lin; Li, Gang; Sun, Jinlong; Jin, Peng; Yang, Jun; Wang, Daokui; Bai, Yunan; Li, Xingang; Fei, Chang; Wang, Chengwei; Wang, Baoan; Pan, Shumao; Du, Jihai; Xie, Bo; Xu, Dongfang; Xin, Changming; Wang, Jihua; Zhang, Qinglin

2015-01-01

This study aimed to describe the technique details of rapid pore cranial drilling with external ventricular drainage and document its clinical outcomes by highlighting the advantages over the traditional and modified cranial drilling technique. Intraventricular hemorrhage is one of the most severe subtypes of hemorrhagic stroke with high mortality. The amount of blood in the ventricles is associated with severity of outcomes, and fast removal of the blood clot is the key to a good prognosis. Between 1977 and 2013, 3773 patients admitted for intraventricular hemorrhage underwent rapid pore cranial drilling drainage. The therapeutic effects and clinical outcomes were retrospectively analyzed. Of these patients, 1049 (27.8%) experienced complete remission, 1788 (47.4%) had improved condition, and 936 (24.8%) died. A total of 3229 (85.6%) patients gained immediate remission. One typical case was illustrated to demonstrate the efficacy of the rapid pore drilling technique. Rapid pore cranial drilling drainage in patients with intraventricular hemorrhage is fast, effective, and provides immediate relief in patients with severe conditions. It could be a better alternative to the conventional drilling approach for treatment of intraventricular hemorrhage. A randomized controlled trial for direct comparison between the rapid pore cranial drilling drainage and conventional drilling technique is in urgent need. PMID:25590642

Rapid Pore Cranial Drilling With External Ventricular Drainage for Treatment of Intraventricular Hemorrhage: A 36-Year Case Series.

PubMed

Zhang, Wei; Wei, Lin; Li, Gang; Sun, Jinlong; Jin, Peng; Yang, Jun; Wang, Daokui; Bai, Yunan; Li, Xingang; Fei, Chang; Wang, Chengwei; Wang, Baoan; Pan, Shumao; Du, Jihai; Xie, Bo; Xu, Dongfang; Xin, Changming; Wang, Jihua; Zhang, Qinglin

2015-06-01

This study aimed to describe the technique details of rapid pore cranial drilling with external ventricular drainage and document its clinical outcomes by highlighting the advantages over the traditional and modified cranial drilling technique. Intraventricular hemorrhage is one of the most severe subtypes of hemorrhagic stroke with high mortality. The amount of blood in the ventricles is associated with severity of outcomes, and fast removal of the blood clot is the key to a good prognosis. Between 1977 and 2013, 3773 patients admitted for intraventricular hemorrhage underwent rapid pore cranial drilling drainage. The therapeutic effects and clinical outcomes were retrospectively analyzed. Of these patients, 1049 (27.8%) experienced complete remission, 1788 (47.4%) had improved condition, and 936 (24.8%) died. A total of 3229 (85.6%) patients gained immediate remission. One typical case was illustrated to demonstrate the efficacy of the rapid pore drilling technique. Rapid pore cranial drilling drainage in patients with intraventricular hemorrhage is fast, effective, and provides immediate relief in patients with severe conditions. It could be a better alternative to the conventional drilling approach for treatment of intraventricular hemorrhage. A randomized controlled trial for direct comparison between the rapid pore cranial drilling drainage and conventional drilling technique is in urgent need.

Decompressive craniectomy and CSF disorders in children.

PubMed

Manfiotto, Marie; Mottolese, Carmine; Szathmari, Alexandru; Beuriat, Pierre-Aurelien; Klein, Olivier; Vinchon, Matthieu; Gimbert, Edouard; Roujeau, Thomas; Scavarda, Didier; Zerah, Michel; Di Rocco, Federico

2017-10-01

Decompressive craniectomy (DC) is a lifesaving procedure but is associated to several post-operative complications, namely cerebrospinal fluid (CSF) dynamics impairment. The aim of this multicentric study was to evaluate the incidence of such CSF alterations after DC and review their impact on the overall outcome. We performed a retrospective multicentric study to analyze the CSF disorders occurring in children aged from 0 to 17 years who had undergone a DC for traumatic brain injury (TBI) in the major Departments of Pediatric Neurosurgery of France between January 2006 and August 2016. Out of 150 children, ranging in age between 7 months and 17 years, mean 10.75 years, who underwent a DC for TBI in 10 French pediatric neurosurgical centers. Sixteen (6 males, 10 females) (10.67%) developed CSF disorders following the surgical procedure and required an extrathecal CSF shunting. External ventricular drainage increased the risk of further complications, especially cranioplasty infection (p = 0.008). CSF disorders affect a minority of children after DC for TBI. They may develop early after the DC but they may develop several months after the cranioplasty (8 months), consequently indicating the necessity of clinical and radiological close follow-up after discharge from the neurosurgical unit. External ventricular drainage and permanent CSF shunt placement increase significantly the risk of cranioplasty infection.

Right coronary artery fistula misdiagnosed as right atrial cardiac myxoma: A case report.

PubMed

Wen, Bing; Yang, Junya; Jiao, Zhouyang; Fu, Guowei; Zhao, Wenzeng

2016-06-01

The current study describes a case of right coronary artery fistula (CAF) misdiagnosed as right atrial myxoma (RAM). A 33-year-old man presented with a 13-year history of intermittent chest pain, and aggravation for 3 days. Echocardiography revealed an occupying lesion in the right atrium producing a partial dynamic tricuspid obstruction. The initial diagnosis was RAM, which causes partial right ventricular inflow tract obstruction. During cardiopulmonary bypass surgery, a giant mass was detected in the anterior wall of the right ventricle and an abnormal vascular fistula was observed at the bottom of the mass. Successful excision of the mass and closure of the fistula completely relieved the patient's presenting symptoms. The disease was subsequently diagnosed as right CAF draining to the myocardial void. The surgical management and misdiagnosis of the case are discussed herein.

Risk stratification for implantable cardioverter defibrillator therapy: the role of the wearable cardioverter-defibrillator.

PubMed

Klein, Helmut U; Goldenberg, Ilan; Moss, Arthur J

2013-08-01

The benefit of implantable cardioverter-defibrillator (ICD) therapy depends upon appropriate evaluation of a persisting risk of sudden death and estimation of the patient's overall survival. Assessment of a stable and unchangeable arrhythmogenic substrate is often difficult. Structural abnormality and ventricular dysfunction, the two major risk parameters, may recover, and heart failure symptoms can improve so that ICD therapy may not be indicated. Risk stratification can take time while the patient continues to be at high risk of arrhythmic death, and patients may need temporary bridging by a defibrillator in cases of interrupted ICD therapy. The wearable cardioverter-defibrillator (WCD) combines a long-term electrocardiogram (ECG)-monitoring system with an external automatic defibrillator. The LIfeVest® (ZOLL, Pittsburgh, PA, USA) is composed of a garment, containing two defibrillation patch electrodes on the back, and an elastic belt with a front-defibrillation patch electrode and four non-adhesive ECG electrodes, connected to a monitoring and defibrillation unit. The WCD is a safe and effective tool to terminate ventricular tachycardia/ventricular fibrillation events, unless a conscious patient withholds shock delivery. It may be used in patients in the early phase after acute myocardial infarction with poor left ventricular function, after acute coronary revascularization procedures (percutaneous coronary intervention or coronary artery bypass grafting) and reduced left ventricular ejection fraction (≤35%), in patients with acute heart failure in non-ischaemic cardiomyopathy of uncertain aetiology and prognosis. The WCD may be helpful in subjects with syncope of assumed tachyarrhythmia origin or in patients with inherited arrhythmia syndromes. The WCD may replace ICD implantation in patients waiting for heart transplantation or who need a ventricular-assist device. This review describes the technical details and characteristics of the WCD, discusses its various potential applications, and reports the currently available experience with the wearable defibrillator.

Lung assist devices influence cardio-energetic parameters: Numerical simulation study.

PubMed

De Lazzari, C; Quatember, B; Recheis, W; Mayr, M; Demertzis, S; Allasia, G; De Rossi, A; Cavoretto, R; Venturino, E; Genuini, I

2015-08-01

We aim at an analysis of the effects mechanical ventilators (MVs) and thoracic artificial lungs (TALs) will have on the cardiovascular system, especially on important quantities, such as left and right ventricular external work (EW), pressure-volume area (PVA) and cardiac mechanical efficiency (CME). Our analyses are based on simulation studies which were carried out by using our CARDIOSIM(©) software simulator. At first, we carried out simulation studies of patients undergoing mechanical ventilation (MV) without a thoracic artificial lung (TAL). Subsequently, we conducted simulation studies of patients who had been provided with a TAL, but did not undergo MV. We aimed at describing the patient's physiological characteristics and their variations with time, such as EW, PVA, CME, cardiac output (CO) and mean pulmonary arterial/venous pressure (PAP/PVP). We were starting with a simulation run under well-defined initial conditions which was followed by simulation runs for a wide range of mean intrathoracic pressure settings. Our simulations of MV without TAL showed that for mean intrathoracic pressure settings from negative (-4 mmHg) to positive (+5 mmHg) values, the left and right ventricular EW and PVA, right ventricular CME and CO decreased, whereas left ventricular CME and the PAP increased. The simulation studies of patients with a TAL, comprised all the usual TAL arrangements, viz. configurations "in series" and in parallel with the natural lung and, moreover, hybrid configurations. The main objective of the simulation studies was, as before, the assessment of the hemodynamic response to the application of a TAL. We could for instance show that, in case of an "in series" configuration, a reduction (an increase) in left (right) ventricular EW and PVA values occurred, whereas the best performance in terms of CO can be achieved in the case of an in parallel configuration.

Regional pressure and temperature variations across the injured human brain: comparisons between paired intraparenchymal and ventricular measurements.

PubMed

Childs, Charmaine; Shen, Liang

2015-06-23

Intraparenchymal, multimodality sensors are commonly used in the management of patients with severe traumatic brain injury (TBI). The 'gold standard', based on accuracy, reliability and cost for intracranial pressure (ICP) monitoring is within the cerebral ventricle (external strain gauge). There are no standards yet for intracerebral temperature monitoring and little is known of temperature differences between brain tissue and ventricle. The aim of the study therefore was to determine pressure and temperature differences at intraparenchymal and ventricular sites during five days of continuous neuromonitoring. Patients with severe TBI requiring emergency surgery. patients who required ICP monitoring were eligible for recruitment. Two intracerebral probe types were used: a) intraventricular, dual parameter sensor (measuring pressure, temperature) with inbuilt catheter for CSF drainage: b) multiparameter intraparenchymal sensor measuring pressure, temperature and oxygen partial pressure. All sensors were inserted during surgery and under aseptic conditions. Seventeen patients, 12 undergoing neurosurgery (decompressive craniectomy n = 8, craniotomy n = 4) aged 21-78 years were studied. Agreement of measures for 9540 brain tissue-ventricular temperature 'pairs' and 10,291 brain tissue-ventricular pressure 'pairs' were determined using mixed model to compare mean temperature and pressure for longitudinal data. There was no significant overall difference for mean temperature (p = 0.92) or mean pressure readings (p = 0.379) between tissue and ventricular sites. With 95.8 % of paired temperature readings within 2SD (-0.4 to 0.4 °C) differences in temperature between brain tissue and ventricle were clinically insignificant. For pressure, 93.5 % of readings pairs fell within the 2SD range (-9.4756 to 7.8112 mmHg). However, for individual patients, agreement for mean tissue-ventricular pressure differences was poor on occasions. There is good overall agreement between paired temperature measurements obtained from deep white matter and brain ventricle in patients with and without early neurosurgery. For paired ICP measurements, 93.5 % of readings were within 2SD of mean difference. Whilst the majority of paired readings were comparable (within 10 mmHg) clinically relevant tissue-ventricular dissociations were noted. Further work is required to unravel the events responsible for short intervals of pressure dissociation before tissue pressure readings can be definitively accepted as a reliable surrogate for ventricular pressure.

Hemodynamic responses to external counterbalancing of auto-positive end-expiratory pressure in mechanically ventilated patients with chronic obstructive pulmonary disease.

PubMed

Baigorri, F; de Monte, A; Blanch, L; Fernández, R; Vallés, J; Mestre, J; Saura, P; Artigas, A

1994-11-01

To study the effect of positive end-expiratory pressure (PEEP) on right ventricular hemodynamics and ejection fraction in patients with chronic obstructive pulmonary disease and positive alveolar pressure throughout expiration by dynamic hyperinflation (auto-PEEP). Open, prospective, controlled trial. General intensive care unit of a community hospital. Ten patients sedated and paralyzed with an acute exacerbation of chronic obstructive pulmonary disease undergoing mechanical ventilation. Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. PEEP was then increased from 0 (PEEP 0) to auto-PEEP level (PEEP = auto-PEEP) and 5 cm H2O above that (PEEP = auto-PEEP +5). At each level of PEEP, airway pressures, flow and volume, hemodynamic variables (including right ventricular ejection fraction by thermodilution technique), and blood gas analyses were recorded. The mean auto-PEEP was 6.6 +/- 2.8 cm H2O and the total PEEP reached was 12.2 +/- 2.4 cm H2O. The degree of lung inflation induced by PEEP averaged 145 +/- 87 mL with PEEP = auto-PEEP and 495 +/- 133 mL with PEEP = auto-PEEP + 5. The PEEP = auto-PEEP caused a right ventricular end-diastolic pressure increase, but there was no other significant hemodynamic change. With PEEP = auto-PEEP + 5, there was a significant increase in intravascular pressures; this amount of PEEP reduced cardiac output (from 4.40 +/- 1.38 L/min at PEEP 0 to 4.13 +/- 1.48 L/min; p < .05). The cardiac output reduction induced by PEEP = auto-PEEP + 5 was > 10% in only five cases and this group of patients had significantly lower right ventricular volumes than the group with less cardiac output variation (right ventricular end-diastolic volume: 64 +/- 9 vs. 96 +/- 26 mL/m2; right ventricular end-systolic volume: 38 +/- 6 vs. 65 +/- 21 mL/m2; p < .05) without significant difference in the other variables that were measured. Neither right ventricular ejection fraction nor right ventricle volumes changed as PEEP increased, but there were marked interpatient differences and also pronounced changes in volume between stages in individual patients. In the study conditions, PEEP application up to values approaching auto-PEEP did not result in the impairment of right ventricular hemodynamics, while higher levels reduced cardiac output in selected patients.

Heterogeneous growth-induced prestrain in the heart

PubMed Central

Genet, M.; Rausch, M.; Lee, L.C.; Choy, S.; Zhao, X.; Kassab, G.S.; Kozerke, S.; Guccione, J.M.; Kuhl, E.

2015-01-01

Even when entirely unloaded, biological structures are not stress-free, as shown by Y.C. Fung’s seminal opening angle experiment on arteries and the left ventricle. As a result of this prestrain, subject-specific geometries extracted from medical imaging do not represent an unloaded reference configuration necessary for mechanical analysis, even if the structure is externally unloaded. Here we propose a new computational method to create physiological residual stress fields in subject-specific left ventricular geometries using the continuum theory of fictitious configurations combined with a fixed-point iteration. We also reproduced the opening angle experiment on four swine models, to characterize the range of normal opening angle values. The proposed method generates residual stress fields which can reliably reproduce the range of opening angles between 8.7±1.8 and 16.6 ± 13.7 as measured experimentally. We demonstrate that including the effects of prestrain reduces the left ventricular stiffness by up to 40%, thus facilitating the ventricular filling, which has a significant impact on cardiac function. This method can improve the fidelity of subject-specific models to improve our understanding of cardiac diseases and to optimize treatment options. PMID:25913241

Evaluation of Persistent Lymphatic Fluid Leakage Using a Strategy of Placing a Drain After Kidney Transplantation: A Statistical Analysis to Assess Its Origin.

PubMed

Inoue, T; Saito, M; Narita, S; Numakura, K; Tsuruta, H; Maeno, A; Tsuchiya, N; Satoh, S; Habuchi, T

2017-10-01

Using a strategy of placing a surgical drain after kidney transplantation, the duration of a lymphatic fluid leakage and prevalence of a symptomatic lymphocele were retrospectively analyzed. The risk factors for persistent lymphatic fluid leakage or asymptomatic lymphocele were evaluated using multivariate analysis to estimate the origin of the lymphatic fluid leakage. Patients with persistent lymphatic fluid leakage and symptomatic lymphocele were defined as those with lymphatic fluid drainage >50 mL for more than 15 days and those who required a percutaneous drainage of the lymphocele, respectively. Persistent lymphatic fluid leakage and symptomatic lymphocele were observed in 40 (16.4%) and 10 (4.1%) of a total of 244 patients, respectively. The maximum durations of lymphatic fluid drainage from the initial drain tube and the second drainage of the symptomatic lymphocele were 48 and 28 days, respectively. Anastomosis of the graft artery to the external iliac artery was an independent risk factor to predict persistent lymphatic fluid leakage or symptomatic lymphocele after kidney transplantation (odds = 2.597, P = .008). The findings of the study suggest that the lymphatic fluid originates from the recipient's iliac lymph trunk rather than from the graft kidney. Copyright © 2017 Elsevier Inc. All rights reserved.

Repair of a mal-repaired biliary injury: a case report.

PubMed

Aldumour, Awad; Aseni, Paolo; Alkofahi, Mohmmad; Lamperti, Luca; Aldumour, Elias; Girotti, Paolo; De Carlis, Luciano-Gregorio

2009-05-14

Iatrogenic bile-duct injury post-laparoscopic cholecystectomy remains a major serious complication with unpredictable long-term results. We present a patient who underwent laparoscopic cholecystectomy for gallstones, in which the biliary injury was recognized intraoperatively. The surgical procedure was converted to an open one. The first surgeon repaired the injury over a T-tube without recognizing the anatomy and type of the biliary lesion, which led to an unusual biliary mal-repair. Immediately postoperatively, the abdominal drain brought a large amount of bile. A T-tube cholangiogram was performed. Despite the contrast medium leaking through the abdominal drain, the mal-repair was unrecognized. The patient was referred to our hospital for biliary leak. Ultrasound and cholangiography was repeated, which showed an unanatomical repair (right to left hepatic duct anastomosis over the T-tube), with evidence of contrast medium coming out through the abdominal drain. Eventually the patient was subjected to a definitive surgical treatment. The biliary continuity was re-established by a Roux-en-Y hepatico-jejunostomy, over transanastomotic external biliary stents. The patient is now doing well 4 years after the second surgical procedure. In reviewing the literature, we found a similar type of injury but we did not find a similar surgical mal-repair. We propose an algorithm for the treatment of early and late biliary injuries.

Repair of a mal-repaired biliary injury: A case report

PubMed Central

Aldumour, Awad; Aseni, Paolo; Alkofahi, Mohmmad; Lamperti, Luca; Aldumour, Elias; Girotti, Paolo; Carlis, Luciano Gregorio De

2009-01-01

Iatrogenic bile-duct injury post-laparoscopic cholecystectomy remains a major serious complication with unpredictable long-term results. We present a patient who underwent laparoscopic cholecystectomy for gallstones, in which the biliary injury was recognized intraoperatively. The surgical procedure was converted to an open one. The first surgeon repaired the injury over a T-tube without recognizing the anatomy and type of the biliary lesion, which led to an unusual biliary mal-repair. Immediately postoperatively, the abdominal drain brought a large amount of bile. A T-tube cholangiogram was performed. Despite the contrast medium leaking through the abdominal drain, the mal-repair was unrecognized. The patient was referred to our hospital for biliary leak. Ultrasound and cholangiography was repeated, which showed an unanatomical repair (right to left hepatic duct anastomosis over the T-tube), with evidence of contrast medium coming out through the abdominal drain. Eventually the patient was subjected to a definitive surgical treatment. The biliary continuity was re-established by a Roux-en-Y hepatico-jejunostomy, over transanastomotic external biliary stents. The patient is now doing well 4 years after the second surgical procedure. In reviewing the literature, we found a similar type of injury but we did not find a similar surgical mal-repair. We propose an algorithm for the treatment of early and late biliary injuries. PMID:19437572

Intraoperative Tumoral Bleeding of Hypervascular Medulloblastoma after Ventricular Drainage: A Case Report.

PubMed

Ryu, Han-Seung; Jung, Tae-Young; Han, Moon-Soo; Kim, Seul-Ki; Lee, Kyung-Hwa

2017-01-01

We report a rare case of intraoperative tumoral bleeding of a hypervascular medulloblastoma. A 12-year-old girl presented with dizziness and nausea. Brain magnetic resonance (MR) images revealed an approximately 4.2-cm enhanced mass on the cerebellar vermis associated with mild perilesional edema and increased cerebral blood volume. Angiography showed tumoral staining and developed occipital and circular dural sinuses in the venous phase. A suboccipital craniotomy was performed. To relieve the intracranial pressure, cerebrospinal fluid (CSF) was drained via a lateral ventricular catheter in the occipital horn. During the opening of the dura, the brain swelling had progressed, and brain computed tomography revealed an intratumoral hemorrhage with brainstem compression. The patient was in a stuporous mental state. A reoperation was performed, and the mass was totally removed. The pathologic findings revealed a medulloblastoma with abnormal enlarged arterial vascular structures. Postoperatively, the patient recovered to an alert mental state. She underwent chemotherapy and radiotherapy. There was no recurrence after 1 year. Pre-resectional CSF drainage should not be routinely performed in posterior fossa tumors, especially with increased cerebral blood volume on MR perfusion images. Complete removal should be performed quickly while CSF drainage should be performed slowly. An intratumoral hemorrhage should be considered in posterior fossa tumors when severe brain swelling suddenly develops after CSF drainage. © 2016 S. Karger AG, Basel.

Hybrid model analysis of intra-aortic balloon pump performance as a function of ventricular and circulatory parameters.

PubMed

Ferrari, Gianfranco; Khir, Ashraf W; Fresiello, Libera; Di Molfetta, Arianna; Kozarski, Maciej

2011-09-01

We investigated the effects of the intra-aortic balloon pump (IABP) on endocardial viability ratio (EVR), cardiac output (CO), end-systolic (V(es)) and end-diastolic (V(ed)) ventricular volumes, total coronary blood flow (TCBF), and ventricular energetics (external work [EW], pressure-volume area [PVA]) under different ventricular (E(max) and diastolic stiffness) and circulatory (arterial compliance) parameters. We derived a hybrid model from a computational model, which is based on merging computational and hydraulic submodels. The lumped parameter computational submodel consists of left and right hearts and systemic, pulmonary, and coronary circulations. The hydraulic submodel includes part of the systemic arterial circulation, essentially a silicone rubber tube representing the aorta, which contains a 40-mL IAB. EVR, CO, V(es), and V(ed), TCBF and ventricular energetics (EW, PVA) were analyzed against the ranges of left ventricular E(max) (0.3-0.5-1 mm Hg/cm(3)) and diastolic stiffness V(stiffness) (≈0.08 and ≈0.3 mm Hg/cm(3), obtained by changing diastolic stiffness constant) and systemic arterial compliance (1.8-2.5 cm(3)/mm Hg). All experiments were performed comparing the selected variables before and during IABP assistance. Increasing E(maxl) from 0.5 to 2 mm Hg/cm(3) resulted in IABP assistance producing lower percentage changes in the selected variables. The changes in ventricular diastolic stiffness strongly influence both absolute value of EVR and its variations during IABP (71 and 65% for lower and higher arterial compliance, respectively). V(ed) and V(es) changes are rather small but higher for lower E(max) and higher V(stiffness). Lower E(max) and higher V(stiffness) resulted in higher TCBF and CO during IABP assistance (∼35 and 10%, respectively). The use of this hybrid model allows for testing real devices in realistic, stable, and repeatable circulatory conditions. Specifically, the presented results show that IABP performance is dependent, at least in part, on left ventricular filling, ejection characteristics, and arterial compliance. It is possible in this way to simulate patient-specific conditions and predict the IABP performance at different values of the circulatory or ventricular parameters. Further work is required to study the conditions for heart recovery modeling, baroreceptor controls, and physiological feedbacks. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Investigation of genesis of gallop sounds in dogs by quantitative phonocardiography and digital frequency analysis.

PubMed

Aubert, A E; Denys, B G; Meno, F; Reddy, P S

1985-05-01

Several investigators have noted external gallop sounds to be of higher amplitude than their corresponding internal sounds (S3 and S4). In this study we hoped to determine if S3 and S4 are transmitted in the same manner as S1. In 11 closed-chest dogs, external (apical) and left ventricular pressures and sounds were recorded simultaneously with transducers with identical sensitivity and frequency responses. Volume and pressure overload and positive and negative inotropic drugs were used to generate gallop sounds. Recordings were made in the control state and after the various interventions. S3 and S4 were recorded in 17 experiments each. The amplitude of the external S1 was uniformly higher than that of internal S1 and internal gallop sounds were inconspicuous. With use of Fourier transforms, the gain function was determined by comparing internal to external S1. By inverse transform, the amplitude of the internal gallop sounds was predicted from external sounds. The internal sounds of significant amplitude were predicted in many instances, but the actual recordings showed no conspicuous sounds. The absence of internal gallop sounds of expected amplitude as calculated from the external gallop sounds and the gain function derived from the comparison of internal and external S1 make it very unlikely that external gallop sounds are derived from internal sounds.

Development of an implantable ventricular assist system.

PubMed

Macris, M P; Parnis, S M; Frazier, O H; Fuqua, J M; Jarvik, R K

1997-02-01

This study describes the present state of progress in the development of the Jarvik 2000 ventricular assist system. Designed for implantation in the human thorax, the system consists of a small (25 cm3, 90 g) intraventricular axial-flow blood pump that transmits power and data via internal electronics and a transcutaneous energy transfer system. The pump is powered by portable internal and external polymer lithium ion batteries. The only moving part, the pump rotor, contains a permanent magnet of a brushless direct-current motor that mounts an axial-flow impeller and partial magnetic thrust support, with blood-immersed radial and thrust bearings. The motor uses a redundant coil and electric lead design, which permits continued operation in case of wire breakage. Seven calves have been supported for an average of 107 days (range, 40 to 162 days) with prototypes of the Jarvik 2000 ventricular assist system. No physiologic complications have occurred. When its user is at rest, the pump produces flows of 5 to 6 L/min with a decreased arterial pulse contour. Renal and hepatic functions have remained normal throughout the duration of all studies. Mean plasma free hemoglobin levels ranged from 4.3 to 11.4 mg/dL (mean, 6.3 mg/dL) for each study. Pathologic analyses of the heart and kidneys revealed no damage related to the device. These studies indicate that the Jarvik 2000 ventricular assist system is feasible in animals and holds promise for long-term support of patients.

[Clinical, electrocardiographic and echocardiographic aspects in elderly hypertensive patients in Senegal].

PubMed

Sarr, Simon Antoine; Babaka, Kana; Mboup, Mouhamadou Cherif; Fall, Pape Diadie; Dia, Khadidiatou; Bodian, Malick; Ndiaye, Mouhamadou Bamba; Kane, Adama; Diao, Maboury; Ba, Serigne Abdou

2016-01-01

Arterial hypertension (HTA) in the elderly is an independent risk factor for cardiovascular disease. Our study aims to describe the clinical, electrocardiographic and echocardiographic aspects of Arterial hypertension in elderly patients. We conducted a descriptive, cross-sectional study from January to September 2013. Hypertensive patients =60 years treated in Outpatient Cardiology Department at the Principal Hospital in Dakar were included in the study. Statistical data were analyzed using Epi Info 7 software and a p-value < 0.05 was taken as significant. A total of 208 patients were enrolled in the study. The average age was 69.9 years with a female predominance (sex ratio 0.85). Average blood pressure was 162/90 mm Hg. HTA was under control in 13% of cases. The ECG showed evidence of rhythm disturbance (17.78%), left atrial enlargement (45.19%), left ventricular hypertrophy (28.85%) and complete atrioventricular block in 2 cases. Holter ECG revealed non-sustained ventricular tachycardia (Lown class IVb) in 4 cases, paroxysmal atrial fibrillation in 6 cases and paroxysmal atrial flutter in 1 case. Echocardiography performed in 140 patients showed mainly concentric left ventricular hypertrophy in 25 patients, occuring more frequently in males (p=0,04) and dilated left atrium in 56,42% of cases, occuring more frequently in elderly patients (p= 0,01). Electrocardiographic and echocardiographic aspects in elderly hypertensive population are characterized by concentric left ventricular hypertrophy and by the frequency of arrhythmias sometimes revealed by long-term continuous external electrocardiographic recording.

Noninvasive measurement of cerebrospinal fluid flow using an ultrasonic transit time flow sensor: a preliminary study.

PubMed

Pennell, Thomas; Yi, Juneyoung L; Kaufman, Bruce A; Krishnamurthy, Satish

2016-03-01

OBJECT Mechanical failure-which is the primary cause of CSF shunt malfunction-is not readily diagnosed, and the specific reasons for mechanical failure are not easily discerned. Prior attempts to measure CSF flow noninvasively have lacked the ability to either quantitatively or qualitatively obtain data. To address these needs, this preliminary study evaluates an ultrasonic transit time flow sensor in pediatric and adult patients with external ventricular drains (EVDs). One goal was to confirm the stated accuracy of the sensor in a clinical setting. A second goal was to observe the sensor's capability to record real-time continuous CSF flow. The final goal was to observe recordings during instances of flow blockage or lack of flow in order to determine the sensor's ability to identify these changes. METHODS A total of 5 pediatric and 11 adult patients who had received EVDs for the treatment of hydrocephalus were studied in a hospital setting. The primary EVD was connected to a secondary study EVD that contained a fluid-filled pressure transducer and an in-line transit time flow sensor. Comparisons were made between the weight of the drainage bag and the flow measured via the sensor in order to confirm its accuracy. Data from the pressure transducer and the flow sensor were recorded continuously at 100 Hz for a period of 24 hours by a data acquisition system, while the hourly CSF flow into the drip chamber was recorded manually. Changes in the patient's neurological status and their time points were noted. RESULTS The flow sensor demonstrated a proven accuracy of ± 15% or ± 2 ml/hr. The flow sensor allowed real-time continuous flow waveform data recordings. Dynamic analysis of CSF flow waveforms allowed the calculation of the pressure-volume index. Lastly, the sensor was able to diagnose a blocked catheter and distinguish between the blockage and lack of flow. CONCLUSIONS The Transonic flow sensor accurately measures CSF output within ± 15% or ± 2 ml/hr, diagnoses the blockage or lack of flow, and records real-time continuous flow data in patients with EVDs. Calculations of a wide variety of diagnostic parameters can be made from the waveform recordings, including resistance and compliance of the ventricular catheters and the compliance of the brain. The sensor's clinical applications may be of particular importance to the noninvasive diagnosis of shunt malfunctions with the development of an implantable device.

Magnetic field enhanced resonant tunneling in a silicon nanowire single-electron-transistor.

PubMed

Aravind, K; Lin, M C; Ho, I L; Wu, C S; Kuo, Watson; Kuan, C H; Chang-Liao, K S; Chen, C D

2012-03-01

We report fabrication, measurement and simulation of silicon single-electron-transistors made on silicon-on-insulator wafers. At T-2 K, these devices showed clear Coulomb blockade structures. An external perpendicular magnetic field was found to enhance the resonant tunneling peak and was used to predict the presence of two laterally coupled quantum dots in the narrow constriction between the source-drain electrodes. The proposed model and measured experimental data were consistently explained using numerical simulations.

Totally implantable total artificial heart and ventricular assist device with multipurpose miniature electromechanical energy system.

PubMed

Takatani, S; Orime, Y; Tasai, K; Ohara, Y; Naito, K; Mizuguchi, K; Makinouchi, K; Damm, G; Glueck, J; Ling, J

1994-01-01

A multipurpose miniature electromechanical energy system has been developed to yield a compact, efficient, durable, and biocompatible total artificial heart (TAH) and ventricular assist device (VAD). Associated controller-driver electronics were recently miniaturized and converted into hybrid circuits. The hybrid controller consists of a microprocessor and controller, motor driver, Hall sensor, and commutation circuit hybrids. The sizing study demonstrated that all these components can be incorporated in the pumping unit of the TAH and VAD, particularly in the centerpiece of the TAH and the motor housing of the VAD. Both TAH and VAD pumping units will start when their power line is connected to either the internal power pack or the external battery unit. As a redundant driving and diagnostic port, an emergency port was newly added and will be placed in subcutaneous location. In case of system failure, the skin will be cut down, and an external motor drive or a pneumatic driver will be connected to this port to run the TAH. This will minimize the circulatory arrest time. Overall efficiency of the TAH without the transcutaneous energy transmission system was 14-18% to deliver pump outputs of 4-9 L/min against the right and left afterload pressures of 25 and 100 mm Hg. The internal power requirement ranged from 6 to 13 W. The rechargeable batteries such as NiCd or NiMH with 1 AH capacity can run the TAH for 30-45 min. The external power requirement, when TETS efficiency of 75% was assumed, ranged from 8 to 18 W. The accelerated endurance test in the 42 degrees C saline bath demonstrated stable performance over 4 months. Long-term endurance and chronic animal studies will continue toward a system with 5 years durability by the year 2000.

A new Subcutaneously Anchored Device for Securing External Cerebrospinal Fluid Catheters: our Preliminary Experience.

PubMed

Frassanito, Paolo; Massimi, Luca; Tamburrini, Gianpiero; Pittiruti, Mauro; Doglietto, Francesco; Nucci, Carlotta Ginevra; Caldarelli, Massimo

2016-09-01

Accidental dislocation or removal is a well-known complication of external cerebrospinal fluid (CSF) drainage in daily clinical practice. At present, no data about the incidence of such complications are available in the scientific literature. SecurAcath (Interrad Medical, Plymouth, Minnesota, USA) is a subcutaneously anchored device recently adopted for securement of central venous catheters, known to be highly effective (and cost-effective) in reducing the risk of catheter dislodgement and/or accidental removal. We report our preliminary experience with the use of SecurAcath to secure CSF drainage, either ventricular or spinal, to the skin. SecurAcath was used in 29 consecutive patients (age range: 3 weeks-16 years, median age 6.3 years). In particular, the device was used for 25 ventricular catheters (a patient received 2 catheters in the same procedure for bilateral brain abscess) and 5 spinal drainages. Period in place ranged from 1-4 weeks (median 22 days). No complication related to the use of the device was observed, in particular there was no case of dislocation or accidental removal of the catheter. The removal procedure was extremely easy. The device has proven its utility also in 3 cases requiring an adjustment of the length of the catheter. In our experience, SecurAcath is a safe and effective device to secure CSF external catheters to the skin, with several relevant advantages: its placement and maintenance are easy; it may stay in place for the entire duration of the catheter; it allows a more complete antisepsis of the exit site, thus reducing local skin complications; it eliminates the risk of suture-related needlestick injuries. Copyright © 2016 Elsevier Inc. All rights reserved.

Frequency-dependent left ventricular performance in women and men.

PubMed

Wainstein, Rodrigo V; Sasson, Zion; Mak, Susanna

2012-06-01

We aimed to determine whether sex differences in humans extend to the dynamic response of the left ventricular (LV) chamber to changes in heart rate (HR). Several observations suggest sex influences LV structure and function in health; moreover, this physiology is also affected in a sex-specific manner by aging. Eight postmenopausal women and eight similarly aged men underwent a cardiac catheterization-based study for force-interval relationships of the LV. HR was controlled by right atrial (RA) pacing, and LV +dP/dt(max) and volume were assessed by micromanometer-tipped catheter and Doppler echocardiography, respectively. Analysis of approximated LV pressure-volume relationships was performed using a time-varying model of elastance. External stroke work was also calculated. The relationship between HR and LV +dP/dt(max) was expressed as LV +dP/dt(max) = b + mHR. The slope (m) of the relationship was steeper in women compared with men (11.8 ± 4.0 vs. 6.1 ± 4.1 mmHg·s(-1)·beats(-1)·min(-1), P = 0.01). The greater increase in contractility in women was reproducibly observed after normalizing LV +dP/dt(max) to LV end-diastolic volume (LVVed) or by measuring end-systolic elastance. LVVed and stroke volume decreased more in women. Thus, despite greater increases in contractility, HR was associated with a lesser rise in cardiac output and a steeper fall in external stroke work in women. Compared with men, women exhibit greater inotropic responses to incremental RA pacing, which occurs at the same time as a steeper decline in external stroke work. In older adults, we observed sexual dimorphism in determinants of LV mechanical performance.

Complicated Pseudomeningocele Repair After Chiari Decompression: Case Report and Review of the Literature.

PubMed

De Tommasi, Claudio; Bond, Aaron E

2016-04-01

Pseudomeningocele is a recognised complication after posterior fossa decompression for Chiari malformation. Its management can be challenging and treatment options vary in literature. A difficult-to-treat case of a pseudomeningocele after posterior fossa decompression for a Chiari I malformation is presented. A 34-year-old woman underwent an initial decompression followed by multiple revision surgeries after the development of a symptomatic pseudomeningocele and a low-grade infection. Complications associated with standard treatment modalities, including lumbar drainage and dural repair, are discussed. A review of the existing literature is presented. The reported case ultimately required complete removal of all dural repair materials to eliminate the patient's low-grade infection, a muscular flap, and placement of a ventricular-peritoneal shunt for definitive treatment after a trial of a lumbar drain led to herniation and development of a syrinx. Copyright © 2016 Elsevier Inc. All rights reserved.

Hemodynamic, pulmonary vascular, and myocardial abnormalities secondary to pharmacologic constriction of the fetal ductus arteriosus. A possible mechanism for persistent pulmonary hypertension and transient tricuspid insufficiency in the newborn infant.

PubMed

Levin, D L; Mills, L J; Weinberg, A G

1979-08-01

The prostaglandin synthetase inhibitor indomethacin was given orally or intravenously to pregnant ewes. This resulted in a significant rise in the fetal pulmonary-to-systemic arterial mean blood pressure difference across the ductus arteriosus, presumably secondary to constriction of the ductus arteriosus. In five experiments the pressure difference could be promptly but temporarily reversed by the administration of prostaglandin E1 (PGE1) into the fetal inferior vena cava. Fetal lungs from study and control animals were fixed by perfusion at measured pulmonary arterial mean blood pressure, and fifth-generation resistance vessels were studied. The medial width/external diameter ratio was significantly increased in the study vs the control lungs due to increased smooth muscle and decreased external diameter. In addition, study fetuses had acute degenerative myocardial changes in the tricuspid valve papillary muscles, the right ventricular free wall and the interventricular septum. Similar changes were not seen in control fetuses. Indomethacin administration during pregnancy causes constriction of the fetal ductus arteriosus, fetal pulmonary arterial hypertension, and right ventricular damage. If severe, this may cause rapid fetal death. If less severe, in the newborn infant, this mechanism may be one cause of persistent pulmonary hypertension due to vasoconstriction and increased pulmonary arterial smooth muscle and/or tricuspid insufficiency due to papillary muscle infarction.

How frequently external ventricular drainage device should be changed in children with ventriculoperitonel shunt infection?

PubMed Central

Gulsen, Ismail; Ak, Hakan; Demir, Nihat; Sosuncu, Enver; Arslan, Mehmet

2015-01-01

Objective: The purpose of the presenting study was to determine how frequently external ventricular drainage (EVD) device should be changed in children with ventriculopertienal shunt (VPS) infection during prolonged intravenous antimicrobial therapy. Methods: In this retrospective study, 25 children with VPS infection were evaluated between January 2012 and December 2013. In these children VPS was surgically removed and appropriate antimicrobial therapy was administered according to cerebrospinal culture results. Data noted about how frequently EVD device had been changed, the number of cells on direct observation of cerebrospinal fluid (CSF), glucose and protein levels of CSF, and CSF culture results were obtained from patients’ records. Results: Total 25 children were included in the study. The median age was three months (1 and 65 months). In 44% of children, Staphylococcus epidermidis was isolated. During treatment period, EVD catheter has changed one to six times. A total of 68 EVD catheters were changed in these patients. When the duration of ventriculostomy catheter and leukocyte count in CSF were evaluated on daily basis, leukocyte count was decreased 5 units per day in children whose catheter remained less than 10 days. However, in children whose catheter remained more than 10 days leukocyte count was decreased 2.21 units per day. Conclusions: In children with VPS infection, EVD device should be changed at every 10 days for the rapid resolution of the infection. PMID:26101506

Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control.

PubMed

Frank, Philipp; Schreiter, Joerg; Haefner, Sebastian; Paschew, Georgi; Voigt, Andreas; Richter, Andreas

2016-01-01

Microfluidics is a great enabling technology for biology, biotechnology, chemistry and general life sciences. Despite many promising predictions of its progress, microfluidics has not reached its full potential yet. To unleash this potential, we propose the use of intrinsically active hydrogels, which work as sensors and actuators at the same time, in microfluidic channel networks. These materials transfer a chemical input signal such as a substance concentration into a mechanical output. This way chemical information is processed and analyzed on the spot without the need for an external control unit. Inspired by the development electronics, our approach focuses on the development of single transistor-like components, which have the potential to be used in an integrated circuit technology. Here, we present membrane isolated chemical volume phase transition transistor (MIS-CVPT). The device is characterized in terms of the flow rate from source to drain, depending on the chemical concentration in the control channel, the source-drain pressure drop and the operating temperature.

Apparatus for sensing patterns of electrical field variations across a surface

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

Warren, William L.; Devine, Roderick A. B.

An array of nonvolatile field effect transistors used to sense electric potential variations. The transistors owe their nonvolatility to the movement of protons within the oxide layer that occurs only in response to an externally applied electric potential between the gate on one side of the oxide and the source/drain on the other side. The position of the protons within the oxide layer either creates or destroys a conducting channel in the adjacent source/channel/drain layer below it, the current in the channel being measured as the state of the nonvolatile memory. The protons can also be moved by potentials createdmore » by other instrumentalities, such as charges on fingerprints or styluses above the gates, pressure on a piezoelectric layer above the gates, light shining upon a photoconductive layer above the gates. The invention allows sensing of fingerprints, handwriting, and optical images, which are converted into digitized images thereof in a nonvolatile format.« less

Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control

PubMed Central

Frank, Philipp; Schreiter, Joerg; Haefner, Sebastian; Paschew, Georgi; Voigt, Andreas; Richter, Andreas

2016-01-01

Microfluidics is a great enabling technology for biology, biotechnology, chemistry and general life sciences. Despite many promising predictions of its progress, microfluidics has not reached its full potential yet. To unleash this potential, we propose the use of intrinsically active hydrogels, which work as sensors and actuators at the same time, in microfluidic channel networks. These materials transfer a chemical input signal such as a substance concentration into a mechanical output. This way chemical information is processed and analyzed on the spot without the need for an external control unit. Inspired by the development electronics, our approach focuses on the development of single transistor-like components, which have the potential to be used in an integrated circuit technology. Here, we present membrane isolated chemical volume phase transition transistor (MIS-CVPT). The device is characterized in terms of the flow rate from source to drain, depending on the chemical concentration in the control channel, the source-drain pressure drop and the operating temperature. PMID:27571209

Piezoelectric potential gated field-effect transistor based on a free-standing ZnO wire.

PubMed

Fei, Peng; Yeh, Ping-Hung; Zhou, Jun; Xu, Sheng; Gao, Yifan; Song, Jinhui; Gu, Yudong; Huang, Yanyi; Wang, Zhong Lin

2009-10-01

We report an external force triggered field-effect transistor based on a free-standing piezoelectric fine wire (PFW). The device consists of an Ag source electrode and an Au drain electrode at two ends of a ZnO PFW, which were separated by an insulating polydimethylsiloxane (PDMS) thin layer. The working principle of the sensor is proposed based on the piezoelectric potential gating effect. Once subjected to a mechanical impact, the bent ZnO PFW cantilever creates a piezoelectric potential distribution across it width at its root and simultaneously produces a local reverse depletion layer with much higher donor concentration than normal, which can dramatically change the current flowing from the source electrode to drain electrode when the device is under a fixed voltage bias. Due to the free-standing structure of the sensor device, it has a prompt response time less than 20 ms and quite high and stable sensitivity of 2%/microN. The effect from contact resistance has been ruled out.

External biliary drainage following major liver resection for perihilar cholangiocarcinoma: impact on development of liver failure and biliary leakage

PubMed Central

Olthof, Pim B.; Coelen, Robert J.S.; Wiggers, Jimme K.; Besselink, Marc G.H.; Busch, Olivier R.C.; van Gulik, Thomas M.

2016-01-01

Background Preoperative biliary drainage is considered essential in perihilar cholangiocarcinoma (PHC) requiring major hepatectomy with biliary-enteric reconstruction. However, evidence for postoperative biliary drainage as to protect the anastomosis is currently lacking. This study investigated the impact of postoperative external biliary drainage on the development of post-hepatectomy biliary leakage and liver failure (PHLF). Methods All patients who underwent major liver resection for suspected PHC between 2000 and 2015 were retrospectively analyzed. Biliary leakage and PHLF was defined as grade B or higher according to the International Study Group of Liver Surgery (ISGLS) criteria. Results Eighty-nine out of 125 (71%) patients had postoperative external biliary drainage. PHLF was more prevalent in the drain group (29% versus 6%; P = 0.004). There was no difference in the incidence of biliary leakage (32% versus 36%). On multivariable analysis, postoperative external biliary drainage was identified as an independent risk factor for PHLF (Odds-ratio 10.3, 95% confidence interval 2.1–50.4; P = 0.004). Conclusions External biliary drainage following major hepatectomy for PHC was associated with an increased incidence of PHLF. It is therefore not recommended to routinely use postoperative external biliary drainage, especially as there is no evidence that this decreases the risk of biliary anastomotic leakage. PMID:27037204

Transmembrane Na+ and Ca2+ electrochemical gradients in cardiac muscle and their relationship to force development

PubMed Central

1982-01-01

Na+- and CA2+-sensitive microelectrodes were used to measure intracellular Na+ and Ca2+ activities (alpha iCa) of sheep ventricular muscle and Purkinje strands to study the interrelationship between Na+ and Ca2+ electrochemical gradients (delta muNa and delta muCa) under various conditions. In ventricular muscle, alpha iNa was 6.4 +/- 1.2 mM and alpha iCa was 87 +/- 20 nM ([Ca/+] = 272 nM). A graded decrease of external Na+ activity (alpha oNa) resulted in decrease of alpha iNa, and increase of alpha iCa. There was increase of twitch tension in low- alpha oNa solutions, and occasional increase of resting tension in 40% alpha oNa. Increase of external Ca2+ (alpha oCa) resulted in increase of alpha iCa and decrease of alpha iNa. Decrease of alpha oCa resulted in decrease of alpha iCa and increase of alpha iNa. The apparent resting Na-Ca energy ratio (delta muCa/delta muNa) was between 2.43 and 2.63. When the membrane potential (Vm) was depolarized by 50 mM K+ in ventricular muscle, Vm depolarized by 50 mV, alpha iNa decreased, and alpha iCa increased, with the development of a contracture. The apparent energy coupling ratio did not change with depolarization. 5 x 10(-6) M ouabain induced a large increase in alpha iNa ad alpha iCa, accompanied by an increase in twitch and resting tension. Under the conditions we have studied, delta muNa and delta muCa appeared to be coupled and n was nearly constant at 2.5, as would be expected if the Na-Ca exchange system was able to set the steady level of alpha iCa. Tension threshold was about 230 nM alpha iCa. The magnitude of twitch tension was directly related to alpha iCa. PMID:6292328

Extension of generator longevity by use of high impedance ventricular leads.

PubMed

Scherer, M; Ezziddin, K; Klesius, A; Skupin, M; Helms, S; Moritz, A; Olbrich, H G

2001-02-01

The resistance of a pacing lead negatively correlates to current consumption. A prospective, randomized trial was conducted to evaluate the effect of a high impedance ventricular lead (CapSure Z) on generator longevity compared to a conventional lead (CapSure SP) eighty-nine patients were included in the study (51 male, 37 female, age 70.0+/-10.3 years). Forty-six patients received a CapSure SP lead (5024 bipolar), and 43 patients received a CapSure Z lead (5034 bipolar) in a randomized fashion. Follow-up data collected at 5 days, 3, 6, and 12 months postimplant included: lead impedance, pacing and sensing thresholds, impulse energy, and estimated time to replacement. All parameters were collected via pacemaker telemetry; the time to replacement was calculated automatically by a programmed algorithm of the pacemaker. There was no difference in the performance of the atrial lead when a dual chamber device was indicated. The CapSure Z leads displayed statistically significant higher impedance values than the CapSure SP lead in all follow-up periods. There was no significant difference in lead related complications. No significant differences were observed between pacing and sensing thresholds in both groups. The CapSure Z leads provided a significant reduction in current drain, resulting in a reduction of mean energy consumption at the 12-month follow-up from 10.4+/-5.0 microJ in the CapSure SP group to 6.6+/-1.4 microJ in the CapSure Z group (median from 9.9 microJ to 6.9 microJ, respectively), providing an estimated increase in mean longevity of more than 1 year from 81.1+/-23.5 months in the CapSure SP group to 94.5+/-13.4 months in the CapSure Z group (median: 76.5 months to 95.0 months, respectively). The use of a high resistance lead for ventricular pacing appears to result in a clinically relevant extension of generator longevity.

Direct current performance and current collapse in AlGaN/GaN insulated gate high-electron mobility transistors on Si (1 1 1) substrate with very thin SiO2 gate dielectric

NASA Astrophysics Data System (ADS)

Lachab, M.; Sultana, M.; Fatima, H.; Adivarahan, V.; Fareed, Q.; Khan, M. A.

2012-12-01

This work reports on the dc performance of AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOSHEMTs) grown on Si (1 1 1) substrate and the study of current dispersion in these devices using various widely adopted methods. The MOSHEMTs were fabricated using a very thin (4.2 nm) SiO2 film as the gate insulator and were subsequently passivated with about 30 nm thick Si3N4 layer. For devices with 2.5 µm long gates and a 4 µm drain-to-source spacing, the maximum saturation drain current density was 822 mA mm-1 at + 4 V gate bias and the peak external transconductance was ˜100 mS mm-1. Furthermore, the oxide layer successfully suppressed the drain and gate leakage currents with the subthreshold current and the gate diode current levels exceeding by more than three orders of magnitude the levels found in their Schottky gate counterparts. Capacitance-voltage and dynamic current-voltage measurements were carried out to assess the oxide quality as well as the devices’ surface properties after passivation. The efficacy of each of these characterization techniques to probe the presence of interface traps and oxide charge in the nitride-based transistors is also discussed.

Wide topical negative pressure wound dressing treatment for patients undergoing abdominal dermolipectomy following massive weight loss.

PubMed

Dragu, Adrian; Schnürer, Stefan; Unglaub, Frank; Wolf, Maya B; Beier, Justus P; Kneser, Ulrich; Horch, Raymund E

2011-11-01

Postbariatric plastic surgery is considered to be a high-risk procedure, which entails such frequent minor complications as postoperative seroma, bleeding and wound dehiscence. These occur with a high incidence, especially, following postbariatric abdominal dermolipectomy. In order to reduce these complication rates, a new type of dressing with wide abdominal topical negative pressure (TNP) application was applied. We performed abdominal dermolipectomy in 23 obese patients. The average body mass index was 32.8 kg/m(2), and the median age of the patients was 42.9 years. Ten patients received conventional standard dressings (control group I), whereas the other 13 patients received a wide TNP dressing including the ventral and lateral trunk (negative pressure group II). Postoperative exudate volumes were collected, tallied and documented for each group separately until all drains could be removed. The conventionally treated control group (I) showed a significantly higher postoperative secretion volume compared with the negative pressure group (II). In addition, the average time to postoperative final drain removal was significantly lower in the negative pressure group (II) compared with the control group (I). The results indicate that widely applied external TNP wound dressing on the ventral and lateral trunk following postbariatric abdominal dermolipectomy leads to a significant reduction in exudate formation, enables early drain removal and thus, decreases length of hospitalization.

Remote magnetic navigation for mapping and ablating right ventricular outflow tract tachycardia.

PubMed

Thornton, Andrew S; Jordaens, Luc J

2006-06-01

Navigation, mapping, and ablation in the right ventricular outflow tract (RVOT) can be difficult. Catheter navigation using external magnetic fields may allow more accurate mapping and ablation. The purpose of this study was to assess the feasibility of RVOT tachycardia ablation using remote magnetic navigation. Mapping and ablation were performed in eight patients with outflow tract ventricular arrhythmias. Tachycardia mapping was undertaken with a 64-polar basket catheter, followed by remote activation and pace-mapping using a magnetically enabled catheter. The area of interest was localized on the basket catheter in seven patients in whom an RVOT arrhythmia was identified. Remote navigation of the magnetic catheter to this area was followed by pace-mapping. Ablation was performed at the site of perfect pace-mapping, with earliest activation if possible. Acute success was achieved in all patients (median four applications). Median procedural time was 144 minutes, with 13.4 minutes of patient fluoroscopy time and 3.8 minutes of physician fluoroscopy time. No complications occurred. One recurrence occurred during follow-up (mean 366 days). RVOT tachycardias can be mapped and ablated using remote magnetic navigation, initially guided by a basket catheter. Precise activation and pace-mapping are possible. Remote magnetic navigation permitted low fluoroscopy exposure for the physician. Long-term results are promising.

Does Late Gadolinium Enhancement still have Value? Right Ventricular Internal Mechanical Work, Ea/Emax and Late Gadolinium Enhancement as Prognostic Markers in Patients with Advanced Pulmonary Hypertension via Cardiac MRI.

PubMed

Abouelnour, Amr Ei; Doyle, Mark; Thompson, Diane V; Yamrozik, June; Williams, Ronald B; Shah, Moneal B; Soma, Siva Kr; Murali, Srinivas; Benza, Raymond L; Biederman, Robert Ww

2017-01-01

Investigate the impact of Right Ventricular (RV) Internal Work (IW), ratio of arterial to ventricular end-systolic elastance (E a /E max ), and RV Insertion Point (IP) Late Gadolinium Enhancement (LGE) on outcome in Pulmonary Hypertension (PH) patients. LGE is well known to be present within the RVIPs and Inter Ventricular Septum (IVS) in PH patients, but its prognostic role remains complex and potentially overestimated via 2D qualitative relative to the 3D quantitative measures now available. However, E a /E max , a measure of ventricular-arterial coupling and IW, when added to external cardiac work i.e. the P-V loop area as correlates to the heart's energy demands, might fundamentally improve measures of prognosis as they interrogate physiology beyond just the RV. Cardiac Magnetic Resonance Imaging (CMR) of 124 PH patients (age = 60±13, 85F) referred to a large tertiary PH center, was retrospectively examined for RV volumetric and functional indices and RVIP LGE%. Right Heart Catheterizations (RHC) performed within 1±2 months of the CMR were reviewed. E a /E max was derived as RV End-Systolic Volume (ESV/RVSV). IW was estimated as RVESV ×(RV end-systolic pressure-RV diastolic pressure). Patients were followed from date of CMR for up to 5 years for MACE (death, hospitalized RV failure, initiation of parenteral prostacyclin, sustained ventricular arrhythmia or referral for lung transplantation). MACE was high; 48/124 (39%) patients had MACE by 1.6±1.3 years. Neither RVIP nor IVS LGE using visual assessment or even 3D quantization predicted MACE. The strongest predictor of MACE was RVIW (OR=1.00013, p<0.002), vs. mPAP, RV mass, RV EF and IP LGE. Surprisingly, neither a single time-point RVIP nor whole IVS LGE% can predict outcome in the largest cohort of PH patients studied to date when compared with conventional or contemporary metrics of disease progression. CMR-LGE appears to lose its' prognostic value in PH patients in stark contradistinction to all other left and right-sided human myocardial pathologies.

A practical review for cardiac rehabilitation professionals of continuous-flow left ventricular assist devices: historical and current perspectives.

PubMed

Compostella, Leonida; Russo, Nicola; Setzu, Tiziana; Bottio, Tomaso; Compostella, Caterina; Tarzia, Vincenzo; Livi, Ugolino; Gerosa, Gino; Iliceto, Sabino; Bellotto, Fabio

2015-01-01

An increasing number of patients with end-stage heart failure are being treated with continuous-flow left ventricular assist devices (cf-LVADs). These patients provide new challenges to the staff in exercise-based cardiac rehabilitation (CR) programs. Even though experience remains limited, it seems that patients supported by cf-LVADs may safely engage in typical rehabilitative activities, provided that some attention is paid to specific aspects, such as the presence of a short external drive line. In spite of initial physical deconditioning, CR allows progressive improvement of symptoms such as fatigue and dyspnea. Intensity of rehabilitative activities should ideally be based on measured aerobic capacity and increased appropriately over time. Regular, long-term exercise training results in improved physical fitness and survival rates. Appropriate adjustment of cf-LVAD settings, together with maintenance of adequate blood volume, provides maximal output, while avoiding suction effects. Ventricular arrhythmias, although not necessarily constituting an immediate life-threatening situation, deserve treatment as they could lead to an increased rate of hospitalization and poorer quality of life. Atrial fibrillation may worsen symptoms of right ventricular failure and reduce exercise tolerance. Blood pressure measurements are possible in cf-LVAD patients only using a Doppler technique, and a mean blood pressure ≤80 mmHg is considered "ideal." Some patients may present with orthostatic intolerance, related to autonomic dysfunction. While exercise training constitutes the basic rehabilitative tool, a comprehensive intervention that includes psychological and social support could better meet the complex needs of patients in which cf-LVAD may offer prolonged survival.

Failure to Treat Life-Threatening Ventricular Tachyarrhythmias in Contemporary Implantable Cardioverter–Defibrillators

PubMed Central

Thøgersen, Anna Margrethe; Larsen, Jacob Moesgaard; Johansen, Jens Brock; Abedin, Moeen

2017-01-01

Background: In clinical trials, manufacturer-specific, strategic programming of implantable cardioverter–defibrillators (ICDs), including faster detection rates, reduces unnecessary therapy but permits therapy for ventricular tachycardia/ventricular fibrillation (VF). Present consensus recommends a generic rate threshold between 185 and 200 beats per minute, which exceeds the rate tested in clinical trials for some manufacturers. In a case series, we sought to determine the relationship between programmed parameters and failure of modern ICDs to treat VF. Methods and Results: We reviewed cases in which normally functioning ICDs failed to deliver timely therapy for VF from April 2015 to January 2017 at 4 institutions. Of 10 ambulatory patients, 5 died from untreated VF, 4 had cardiac arrests requiring external shocks, and 1 was rescued by a delayed ICD shock. VF did not satisfy programmed detection criteria in 9 patients (90%). Seven of these patients had slowest detection rates that were consistent with generic recommendations but not tested in a peer-reviewed trial for their manufacturer’s ICDs. Manufacturer-specific factors interacted with fast detection rates to withhold therapy, including strict VF episode termination rules, enhancements to minimize T-wave oversensing, and features that restrict therapy to regular rhythms in ventricular tachycardia zones. Untreated VF despite recommended programming accounted for 56% of sudden deaths and 11% of all deaths during the study period. Conclusions: Complex and unanticipated interactions between manufacturer-specific features and generic programming can prevent therapy for VF. More data are needed to assess the risks and benefits of translating evidence-based detection parameters from one manufacturer to another. PMID:28916511

Predicting Outcome in Subarachnoid Hemorrhage (SAH) Utilizing the Full Outline of UnResponsiveness (FOUR) Score.

PubMed

Zeiler, F A; Lo, B W Y; Akoth, E; Silvaggio, J; Kaufmann, A M; Teitelbaum, J; West, M

2017-12-01

Existing scoring systems for aneurysmal subarachnoid hemorrhage (SAH) patients fail to accurately predict patient outcome. Our goal was to prospectively study the Full Outline of UnResponsiveness (FOUR) score as applied to newly admitted aneurysmal SAH patients. All adult patients presenting to Health Sciences Center in Winnipeg from January 2013 to July 2015 (2.5 year period) with aneurysmal SAH were prospectively enrolled in this study. All patients were followed up to 6 months. FOUR score was calculated upon admission, with repeat calculation at 7 and 14 days. The primary outcomes were: mortality, as well as dichotomized 1- and 6-month Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) values. Sixty-four patients were included, with a mean age of 54.2 years (range 26-85 years). The mean FOUR score upon admission pre- and post-external ventricular drain (EVD) was 10.3 (range 0-16) and 11.1 (range 3-16), respectively. There was a statistically significant association between pre-EVD FOUR score (total, eye, respiratory and motor sub-scores) with mortality, 1-month GOS, and 6-month GOS/mRS (p < 0.05 in all). The day 7 total, eye, respiratory, and motor FOUR scores were associated with mortality, 1-month GOS/mRS, and 6-month GOS/mRS (p < 0.05 in all). The day 14 total, eye, respiratory, and motor FOUR scores were associated with 6-month GOS (p < 0.05 in all). The day 7 cumulative FOUR score was associated with the development of clinical vasospasm (p < 0.05). The FOUR score at admission and day 7 post-SAH is associated with mortality, 1-month GOS/mRS, and 6-month GOS/mRS. The FOUR score at day 14 post-SAH is associated with 6-month GOS. The brainstem sub-score was not associated with 1- or 6-month primary outcomes.

Prognostic significance of blood-brain barrier disruption in patients with severe nonpenetrating traumatic brain injury requiring decompressive craniectomy.

PubMed

Ho, Kwok M; Honeybul, Stephen; Yip, Cheng B; Silbert, Benjamin I

2014-09-01

The authors assessed the risk factors and outcomes associated with blood-brain barrier (BBB) disruption in patients with severe, nonpenetrating, traumatic brain injury (TBI) requiring decompressive craniectomy. At 2 major neurotrauma centers in Western Australia, a retrospective cohort study was conducted among 97 adult neurotrauma patients who required an external ventricular drain (EVD) and decompressive craniectomy during 2004-2012. Glasgow Outcome Scale scores were used to assess neurological outcomes. Logistic regression was used to identify factors associated with BBB disruption, defined by a ratio of total CSF protein concentrations to total plasma protein concentration > 0.007 in the earliest CSF specimen collected after TBI. Of the 252 patients who required decompressive craniectomy, 97 (39%) required an EVD to control intracranial pressure, and biochemical evidence of BBB disruption was observed in 43 (44%). Presence of disruption was associated with more severe TBI (median predicted risk for unfavorable outcome 75% vs 63%, respectively; p = 0.001) and with worse outcomes at 6, 12, and 18 months than was absence of BBB disruption (72% vs 37% unfavorable outcomes, respectively; p = 0.015). The only risk factor significantly associated with increased risk for BBB disruption was presence of nonevacuated intracerebral hematoma (> 1 cm diameter) (OR 3.03, 95% CI 1.23-7.50; p = 0.016). Although BBB disruption was associated with more severe TBI and worse long-term outcomes, when combined with the prognostic information contained in the Corticosteroid Randomization after Significant Head Injury (CRASH) prognostic model, it did not seem to add significant prognostic value (area under the receiver operating characteristic curve 0.855 vs 0.864, respectively; p = 0.453). Biochemical evidence of BBB disruption after severe nonpenetrating TBI was common, especially among patients with large intracerebral hematomas. Disruption of the BBB was associated with more severe TBI and worse long-term outcomes, but when combined with the prognostic information contained in the CRASH prognostic model, this information did not add significant prognostic value.

Mortality Rates After Emergent Posterior Fossa Decompression for Ischemic or Hemorrhagic Stroke in Older Patients.

PubMed

Puffer, Ross C; Graffeo, Christopher; Rabinstein, Alejandro; Van Gompel, Jamie J

2016-08-01

Cerebellar stroke causes major morbidity in the aging population. Guidelines from the American Stroke Association recommend emergent decompression in patients who have brainstem compression, hydrocephalus, or clinical deterioration. The objective of this study was to determine 30-day and 1-year mortality rates in patients >60 years old undergoing emergent posterior fossa decompression. Surgical records identified all patients >60 years old who underwent emergent posterior fossa decompression. Mortality rates were calculated at 30 days and 1 year postoperatively, and these rates were compared with patient and procedure characteristics. During 2000-2014, 34 emergent posterior fossa decompressions were performed in patients >60 years old. Mortality rates at 30 days were 0%, 33%, and 25% for age deciles 60-69 years, 70-79 years, and ≥80 years. Increasing age (alive at 30 days 75.2 years ± 1.7 vs. deceased 81.1 years ± 1.7, P = 0.01) and smaller craniectomy dimensions were associated with 30-day mortality. Mortality rates at 1 year were 0%, 50%, and 67% for age deciles 60-69 years, 70-79 years, and ≥80 years. Increasing age was significantly associated with mortality at 1 year (alive at 1 year 72.3 years ± 2.0 vs. deceased 81.1 years ± 1.2, P < 0.01). Type of pathology, side of pathology, volume of bleed/infarct, and placement of an external ventricular drain were not associated with mortality. Age was independent of admission Glasgow Coma Scale score as a predictor of mortality at 30 days, 90 days, and 1 year postoperatively. Increasing age and smaller craniectomy size were significantly associated with mortality in patients undergoing emergent posterior fossa decompression. Among patients ≥80 years old, one-quarter were dead within 1 month of the operation, and more than two-thirds were dead within 1 year. Copyright © 2016 Elsevier Inc. All rights reserved.

Neuro-critical care: a valuable placement during foundation and early neurosurgical training.

PubMed

Dyson, Edward W; Kolias, Angelos G; Burnstein, Rowan M; Hutchinson, Peter J A; Garnett, Matthew R; Menon, David K; Trivedi, Rikin A

2014-10-01

Neurosciences critical care units (NCCUs) present a unique opportunity to junior trainees in neurosurgery as well as foundation trainees looking to gain experience in the management of critically ill patients with neurological conditions. Placements in NCCUs are undertaken in the early years of neurosurgical training or during neurosciences themed foundation programmes. We sought to quantify the educational benefits of such placements from the trainee perspective. Thirty-two trainees who had undertaken placements at Foundation Year 2 (FY2) to Specialty Trainee Year 3 (ST3) level between August 2009 and April 2013 were invited to take part in an online questionnaire survey. Competence in individual skills was self-rated on a ranked scale from one (never observed) to five (performed unsupervised) both before and after the placement. Trainees were also asked a series of questions pertaining to their ability to manage common neurosurgical conditions, as well as the perceived educational rigour of their placement. Twenty-three responses were received. Eighteen responses were from FY2s and seven were from ST1-3 level trainees. Following their placements, 100% of respondents felt better equipped to deal with neurosurgical and neurological emergencies and cranial trauma. Most felt better equipped to manage hydrocephalus (95.7%), polytrauma patients (95.7%), spontaneous intracranial haemorrhage (91.3%) and spinal trauma (82.6%). Significant increases were seen in experience in all practical skills assessed. These included central venous catheterisation (p < 0.001), intracranial pressure (ICP) bolt insertion (p < 0.001), ICP bolt removal (p < 0.001), external ventricular drain (EVD) insertion (p = 0.001) and tapping of EVD for cerebrospinal fluid sample (p < 0.001). Our results clearly demonstrate the educational benefits of NCCU placements in the early stages of a neurosurgical training programme as well as in the Foundation Programme. This supports the incorporation of a four- to six-month NCCU rotation in early years training as educationally valuable.

Raised Proinflammatory Cytokine Production Within Cerebrospinal Fluid Precedes Fever Onset in Patients With Neurosurgery-Associated Bacterial Meningitis.

PubMed

Liu, Zhuo-Hao; Tu, Po-Hsun; Chen, Nan-Yu; Yip, Ping K; Bowes, Amy L; Lee, Cheng-Chi; Chan, She-Hung; Kung, Chua-Chi; Wang, Alvin Yi-Chou; Wu, Chieh-Tsai; Lee, Shih-Tseng

2015-11-01

The objective of the present study was to determine whether selective inflammatory cytokine concentrations within cerebrospinal fluid are useful markers for the differential diagnosis of aseptic and bacterial meningitis within neurosurgical patients. Prospective, open-label, observational, cohort study. Neurosurgical ICU, Chang Gung Memorial Hospital. Thirty-two consecutive neurosurgical patients who had postoperative fever following external ventricular drain insertion for the treatment of brain injury underwent serial cerebrospinal fluid cytokine analysis pre and post fever to determine the value of such markers in ascertaining the differential diagnosis of meningitis. Cerebrospinal fluid samples were collected on the day of fever onset, as well as on day 2 and 4 pre and post fever development. Tumor necrosis factor-α, interleukin-1β, interleukin-6, interleukin-8, transforming growth factor-β, and procalcitonin were subsequently analyzed using enzyme-linked immunosorbent assay analysis techniques. Inflammatory marker levels were compared among febrile aseptic, bacterial, and nonmeningitis patients to determine cerebrospinal fluid inflammatory changes over time. Significant increases in cerebrospinal fluid tumor necrosis factor -α, interleukin-1β, interleukin-6, and interleukin-8 levels were observed within patients with bacterial meningitis at fever onset, which was not evident in aseptic or nonmeningitis patients. Furthermore, significant increases in cerebrospinal fluid tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8 levels were detected as early as 4 days prior to fever onset within patients with bacterial meningitis when compared with both aseptic and nonmeningitis groups. Interestingly, procalcitonin was only significantly increased in patients with bacterial meningitis on the fourth day post fever. The present study suggests that raised cerebrospinal fluid tumor necrosis factor -α, interleukin-1β, and interleukin-8 in a temporal manner may indicate early bacterial meningitis development in neurosurgical patients, enabling earlier diagnostic certainty and improved patient outcomes.

Electrical cardioversion

PubMed Central

Sucu, Murat; Davutoglu, Vedat; Ozer, Orhan

2009-01-01

External electrical cardioversion was first performed in the 1950s. Urgent or elective cardioversions have specific advantages, such as termination of atrial and ventricular tachycardia and recovery of sinus rhythm. Electrical cardioversion is life-saving when applied in urgent circumstances. The succcess rate is increased by accurate tachycardia diagnosis, careful patient selection, adequate electrode (paddles) application, determination of the optimal energy and anesthesia levels, prevention of embolic events and arrythmia recurrence and airway conservation while minimizing possible complications. Potential complications include ventricular fibrillation due to general anesthesia or lack of synchronization between the direct current (DC) shock and the QRS complex, thromboembolus due to insufficient anticoagulant therapy, non-sustained VT, atrial arrhythmia, heart block, bradycardia, transient left bundle branch block, myocardial necrosis, myocardial dysfunction, transient hypotension, pulmonary edema and skin burn. Electrical cardioversion performed in patients with a pacemaker or an incompatible cardioverter defibrillator may lead to dysfunction, namely acute or chronic changes in the pacing or sensitivity threshold. Although this procedure appears fairly simple, serious consequences might occur if inappropriately performed. PMID:19448376

Development and evaluation of a long-term, implantable, electrically actuated left ventricular assist system: THI/Gould LVAS.

PubMed

Norman, J C; McGee, M G; Fuqua, J M; Igo, S R; Turner, S A; Sterling, R; Urrutia, C O; Frazier, O H; Clay, W C; Chambers, J A

1983-02-01

A long-term, implantable, electrically actuated left ventricular assist system (THI/Gould LVAS) is being developed and characterized in vitro and in vivo for utilization in patients with end-stage heart disease. This system consists of five major components: a long-term, implantable blood pump (THI E-type ALVAD); an electrical-mechanical energy converter (Gould Model V); a control unit with batteries; a volume compensation system; and an external power supply and monitoring unit. Two of these components (blood pump and electrical-mechanical energy converter) have been integrated, and are undergoing chronic in vivo evaluations in calves. Thus far, 44 pneumatically and electrically actuated THI/Gould LVAS evaluations have been performed. This experience has resulted in greater than 6.5 years of actuation in vivo, with durations exceeding 1 year. System in vivo performance in terms of durability, mechanical reliability, hemodynamic effectiveness, and biocompatibility has been satisfactory. Demonstration of long-term (2-year) effectiveness in supporting the circulation is the ultimate goal.

Heart rate-left ventricular ejection time relations - Variations during postural change and cardiovascular challenges

NASA Technical Reports Server (NTRS)

Lance, V. Q.; Spodick, D. H.

1976-01-01

Experiments were conducted on healthy human subjects to determine HR-LVET (Heart Rate-Left Ventricular Ejection Time) regression relations in different postures, including tilt, and during isometric exercise. The subjects were tested in the resting state in supine and sitting positions, during isometric handgrip in supine and sitting positions and during 70 deg headup tilt. The recordings included a bipolar electrocardiogram and a right external carotid pulse curve. Comparison of the HR-LVET relation for the conditions under analysis revealed differences among the respective regression equations, which can be explained by the well-established differences in stroke volume and ejection rate among these states. These differences appear to account for the fact that under conditions in which stroke volume variations should be the major determinant, slopes will be similar but intercepts will vary. Since substantial differences among intercepts are observed, caution should be exercised whenever the intercept factor is used to predict LVET for HR.

Correction of aortic insufficiency with an external adjustable prosthetic aortic ring.

PubMed

Gogbashian, Andrew; Ghanta, Ravi K; Umakanthan, Ramanan; Rangaraj, Aravind T; Laurence, Rita G; Fox, John A; Cohn, Lawrence H; Chen, Frederick Y

2007-09-01

Less invasive, valve-sparing options are needed for patients with aortic insufficiency (AI). We sought to evaluate the feasibility of reducing AI with an external adjustable aortic ring in an ovine model. To create AI, five sheep underwent patch plasty enlargement of the aortic annulus and root by placement of a 10 x 15 mm pericardial patch between the right and noncoronary cusps. An adjustable external ring composed of a nylon band was fabricated and placed around the aortic root. Aortic flow, aortic pressure, and left ventricular pressures were measured with the ring loose (off) and tightened (on). Mean regurgitant orifice area decreased by 86%, from 0.07 +/- 0.03 cm2 (ring loose, off) to 0.01 +/- 0.00 cm2 (ring tightened, on) [p < 0.01]. The regurgitant fraction decreased from 18 +/- 4% to 2 +/- 1% [p < 0.01]. The ring did not significantly affect stroke volume and aortic pressure. An ovine model of aortic root dilatation resulting in acute AI has been developed. In this model, application of an external, adjustable constricting aortic ring eliminated AI. An aortic ring may be a useful adjunct in reducing AI secondary to annular dilatation.

Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency.

PubMed

Hansson, Nils Henrik; Tolbod, Lars; Harms, Johannes; Wiggers, Henrik; Kim, Won Yong; Hansen, Esben; Zaremba, Tomas; Frøkiær, Jørgen; Jakobsen, Steen; Sørensen, Jens

2016-08-01

Noninvasive estimation of myocardial external efficiency (MEE) requires measurements of left ventricular (LV) oxygen consumption with [(11)C]acetate PET in addition to LV stroke volume and mass with cardiovascular magnetic resonance (CMR). Measuring LV geometry directly from ECG-gated [(11)C]acetate PET might enable MEE evaluation from a single PET scan. Therefore, we sought to establish the accuracy of measuring LV volumes, mass, and MEE directly from ECG-gated [(11)C]acetate PET. Thirty-five subjects with aortic valve stenosis underwent ECG-gated [(11)C]acetate PET and CMR. List mode PET data were rebinned into 16-bin ECG-gated uptake images before measuring LV volumes and mass using commercial software and compared to CMR. Dynamic datasets were used for calculation of mean LV oxygen consumption and MEE. LV mass, volumes, and ejection fraction measured by CMR and PET correlated strongly (r = 0.86-0.92, P < .001 for all), but were underestimated by PET (P < .001 for all except ESV P = .79). PET-based MEE, corrected for bias, correlated fairly with PET/CMR-based MEE (r = 0.60, P < .001, bias -3 ± 21%, P = .56). PET-based MEE bias was strongly associated with LV wall thickness. Although analysis-related improvements in accuracy are recommended, LV geometry estimated from ECG-gated [(11)C]acetate PET correlate excellently with CMR and can indeed be used to evaluate MEE.

[In-hospital resuscitation. Concept of first-responder resuscitation using semi-automated external defibrillators (AED)].

PubMed

Hanefeld, C; Lichte, C; Laubenthal, H; Hanke, E; Mügge, A

2006-09-29

The prognosis after in-hospital resuscitation has not significantly improved in the last 40 years. This account presents the results over a three-year period of a hospital-wide emergency plan which implements the use of an automated external defibrillator (AED) by the first responder to the emergency call. 15 "defibrillator points" were installed, which could be reached within 30 s from all wards, out-patient departments and other areas, thus making them accessible for immediate defibrillator application. The hospital personnel is trained periodically in the alarm sequence, cardiopulmonary resuscitation and use of the defibrillator. Data on 57 patients who had sustained a cardiac arrest were prospectively recorded and analysed. In 46 patients (81%) the "on-the-spot" personnel (first-responder) was able to apply AED before arrival of the hospital's resuscitation team. Mean period between arrest alarm and activation of the AED was 2.2 (0.7-4.7) min. Ventricular fibrillation or ventricular tachyarrhythmia was recorded in 40 patients, making immediate shock delivery by AED possible. Restoration of the circulation was achieved in 23 (80%) of the patients and 20 (50%) were discharged home, 17 (43%) without neurological deficit. The high proportion of first-responder AED applications and evaluation of the personnel training indicate a wide acceptance of the emergency plan among the personnel. An immediate resuscitation plan consisting of an integrated programme of early defibrillation is feasible and seems to achieve an improved prognosis for patients who have sustained an in-hospital cardiac arrest.

Strain-effect transistors: Theoretical study on the effects of external strain on III-nitride high-electron-mobility transistors on flexible substrates

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

Shervin, Shahab; Asadirad, Mojtaba; Materials Science and Engineering Program, University of Houston, Houston, Texas 77204

This paper presents strain-effect transistors (SETs) based on flexible III-nitride high-electron-mobility transistors (HEMTs) through theoretical calculations. We show that the electronic band structures of InAlGaN/GaN thin-film heterostructures on flexible substrates can be modified by external bending with a high degree of freedom using polarization properties of the polar semiconductor materials. Transfer characteristics of the HEMT devices, including threshold voltage and transconductance, are controlled by varied external strain. Equilibrium 2-dimensional electron gas (2DEG) is enhanced with applied tensile strain by bending the flexible structure with the concave-side down (bend-down condition). 2DEG density is reduced and eventually depleted with increasing compressive strainmore » in bend-up conditions. The operation mode of different HEMT structures changes from depletion- to enchantment-mode or vice versa depending on the type and magnitude of external strain. The results suggest that the operation modes and transfer characteristics of HEMTs can be engineered with an optimum external bending strain applied in the device structure, which is expected to be beneficial for both radio frequency and switching applications. In addition, we show that drain currents of transistors based on flexible InAlGaN/GaN can be modulated only by external strain without applying electric field in the gate. The channel conductivity modulation that is obtained by only external strain proposes an extended functional device, gate-free SETs, which can be used in electro-mechanical applications.« less

Strain-Gated Field Effect Transistor of a MoS2-ZnO 2D-1D Hybrid Structure.

PubMed

Chen, Libo; Xue, Fei; Li, Xiaohui; Huang, Xin; Wang, Longfei; Kou, Jinzong; Wang, Zhong Lin

2016-01-26

Two-dimensional (2D) molybdenum disulfide (MoS2) is an exciting material due to its unique electrical, optical, and piezoelectric properties. Owing to an intrinsic band gap of 1.2-1.9 eV, monolayer or a-few-layer MoS2 is used for fabricating field effect transistors (FETs) with high electron mobility and on/off ratio. However, the traditional FETs are controlled by an externally supplied gate voltage, which may not be sensitive enough to directly interface with a mechanical stimulus for applications in electronic skin. Here we report a type of top-pressure/force-gated field effect transistors (PGFETs) based on a hybrid structure of a 2D MoS2 flake and 1D ZnO nanowire (NW) array. Once an external pressure is applied, the piezoelectric polarization charges created at the tips of ZnO NWs grown on MoS2 act as a gate voltage to tune/control the source-drain transport property in MoS2. At a 6.25 MPa applied stimulus on a packaged device, the source-drain current can be tuned for ∼25%, equivalent to the results of applying an extra -5 V back gate voltage. Another type of PGFET with a dielectric layer (Al2O3) sandwiched between MoS2 and ZnO also shows consistent results. A theoretical model is proposed to interpret the received data. This study sets the foundation for applying the 2D material-based FETs in the field of artificial intelligence.

A detrital garnet fingerprint of the Central Swiss Alps

NASA Astrophysics Data System (ADS)

Stutenbecker, Laura; Berger, Alfons; Schlunegger, Fritz

2017-04-01

Detrital garnet is a promising candidate to reliably fingerprint sediment sources in the Alps, which has so far been complicated by the wide range and similarity of some of the lithologies. Garnet is present in most Alpine sediments, is easy to identify, is fairly stable and, most importantly, reflects the type and the metamorphic grade of its source rock in its chemical composition. This study aims to establish fingerprints based on detrital garnet composition for the most important tectonic units of the Central Alps, including European, Penninic and Adriatic basement rocks and their respective meta-sedimentary cover. Sediments collected from modern rivers, which drain representative portions of the individual tectonic units, contain a natural mixture of the various garnet populations present in each unit. We selected six catchments in southwestern Switzerland draining the External Massifs, Helvetic sediments and the Penninic nappe stack at the transition of Alpine greenschist- to amphibolite-facies metamorphism in order to test the variability of Alpine garnets and the role of inherited (pre-Alpine) garnets. Extraordinary grossular- and spessartine-rich garnets of the External massifs, which experienced greenschist facies metamorphism, are clearly distinguishable from generally almandine-rich garnets supplied by the higher-grade metamorphic Penninic nappe stack. The variable pyrope-, grossular- and spessartine-components of these almandine-rich garnets can be used to further distinguish pre-Alpine, Alpine eclogite-facies and low-grade metasedimentary garnets. This fingerprint has the potential to be used for reconstructing sediment sources, transport and dispersal patterns in a variety of settings throughout the Alpine sedimentary record.

The potential of detrital garnet as a provenance proxy in the Central Swiss Alps

NASA Astrophysics Data System (ADS)

Stutenbecker, Laura; Berger, Alfons; Schlunegger, Fritz

2017-04-01

Detrital garnet is a promising candidate to reliably fingerprint sediment sources in the Alps, which has so far been complicated by the wide range and similarity of some of the lithologies. Garnet is present in most Alpine sediments, is easy to identify, is fairly stable and, most importantly, reflects the type and the metamorphic grade of its source rock in its chemical composition. This study aims to establish fingerprints based on detrital garnet composition for the most important tectonic units of the Central Alps, including European, Penninic and Adriatic basement rocks and their respective metasedimentary covers. Sediments collected from modern rivers, which drain representative portions of the individual tectonic units, contain a natural mixture of the various garnet populations present in each unit. We selected six catchments in southwestern Switzerland draining the External massifs, Helvetic sediments and the Penninic nappe stack at the transition of Alpine greenschist- to amphibolite-facies metamorphism in order to test the variability of Alpine garnets and the role of inherited (pre-Alpine) garnets. Extraordinary grossular- and spessartine-rich garnets of the External massifs, which experienced greenschist facies metamorphism, are clearly distinguishable from generally almandine-rich garnets supplied by the higher-grade metamorphic Penninic nappe stack. The variable pyrope, grossular and spessartine components of these almandine-rich garnets can be used to further distinguish pre-Alpine, Alpine eclogite-facies and low-grade metasedimentary garnets. This provenance proxy has the potential to be used for reconstructing sediment sources, transport and dispersal patterns in a variety of settings throughout the Alpine sedimentary record.

KSC-2010-5939

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Shown here, is one of two solid rocket boosters, which are still attached to the external tank and shuttle. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5945

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Shown here is the nose of the shuttle, which still is attached to the external tank and solid rocket boosters. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

Photo-thermoelectric properties of SnS nanocrystals with orthorhombic layered structure

NASA Astrophysics Data System (ADS)

Hyun, Cheol-Min; Choi, Jeong-Hun; Lee, Myoung-Jae; Ahn, Ji-Hoon

2017-07-01

The photo-thermoelectric properties of SnS nanocrystals, two-dimensional materials with an orthorhombic symmetry, were investigated using a focused laser scanning method. The SnS nanocrystals were synthesized by a vapor transport method, and their fundamental material and electrical properties were investigated. Upon shining a laser onto the SnS channel region under a positive source-drain bias, a positive photocurrent was observed due to photo-excited electron-hole pairs. On the other hand, when this external electric field was not applied, a strong photocurrent was observed within the metal electrode region rather than at the metal-semiconductor interface, which indicated that the major mechanism for the photocurrent under zero external bias was a photo-induced thermoelectric effect rather than a photovoltaic effect. Moreover, the Seebeck coefficient of the SnS nanocrystal device was approximately 1735 μV/K, which is 3.5 times larger than that of its bulk counterpart.

Characterization of structural and electrical properties of ZnO tetrapods

NASA Astrophysics Data System (ADS)

Gu, Yu-Dong; Mai, Wen-Jie; Jiang, Peng

2011-12-01

ZnO tetrapods were synthesized by a typical thermal vapor-solid deposition method in a horizontal tube furnace. Structural characterization was carried out by transmission electron microscopy (TEM) and select-area electron diffraction (SAED), which shows the presence of zinc blende nucleus in the center of tetrapods while the four branches taking hexagonal wurtzite structure. The electrical transport property of ZnO tetrapods was investigated through an in-situ nanoprobe system. The three branches of a tetrapod serve as source, drain, and "gate", respectively; while the fourth branch pointing upward works as the force trigger by vertically applying external force downward. The conductivity of each branch of ZnO-tetrapods increases 3-4 times under pressure. In such situation, the electrical current through the branches of ZnO tetrapods can be tuned by external force, and therefore a simple force sensor based on ZnO tetrapods has been demonstrated for the first time.

Fundamental and future prospects of printed ambipolar fluorene-type polymer light-emitting transistors for improved external quantum efficiency, mobility, and emission pattern

NASA Astrophysics Data System (ADS)

Kajii, Hirotake

2018-05-01

In this review, we focus on the improved external quantum efficiency, field-effect mobility, and emission pattern of top-gate-type polymer light-emitting transistors (PLETs) based on ambipolar fluorene-type polymers. A low-temperature, high-efficiency, printable red phosphorescent PLET based on poly(alkylfluorene) with modified alkyl side chains fabricated by a film transfer process is demonstrated. Device fabrication based on oriented films leads to an improved EL intensity owing to the increase in field-effect mobility. There are three factors that affect the transport of carriers, i.e., the energy level, threshold voltage, and mobility of each layer for heterostructure PLETs, which result in various emission patterns such as the line-shaped, multicolor and in-plane emission pattern in the full-channel area between source and drain electrodes. Fundamentals and future prospects in heterostructure devices are discussed and reviewed.

Transport model of controlled molecular rectifier showing unusual negative differential resistance effect.

PubMed

Granhen, Ewerton Ramos; Reis, Marcos Allan Leite; Souza, Fabrício M; Del Nero, Jordan

2010-12-01

We investigate theoretically the charge accumulated Q in a three-terminal molecular device in the presence of an external electric field. Our approach is based on ab initio Hartree-Fock and density functional theory methodology contained in Gaussian package. Our main finding is a negative differential resistance (NDR) in the charge Q as a function of an external electric field. To explain this NDR effect we apply a phenomenological capacitive model based on a quite general system composed of many localized levels (that can be LUMOs of a molecule) coupled to source and drain. The capacitance accounts for charging effects that can result in Coulomb blockade (CB) in the transport. We show that this CB effect gives rise to a NDR for a suitable set of phenomenological parameters, like tunneling rates and charging energies. The NDR profile obtained in both ab initio and phenomenological methodologies are in close agreement.

Bile duct injury during cholecystectomy.

PubMed

Kapoor, V K

2015-08-01

Laparoscopic cholecystectomy (LC) is the treatment of choice for gallstones, but is associated with increased risk of bile duct injury (BDI bile duct injury). If the BDI is detected during LC can be addressed immediately, if available hepatobiliary surgeon, but the easiest and safest procedure for the general surgeon is placing drains into subhepatic region and the transfer of acute BDI to controlled external biliary fistula (external Biliary fistula EBF). Most BDI is diagnosed when the postoperative period, when there is biliary leak. Therapy is a percutaneous catheter drainage and endoscopic stenting in the bile duct; early repair is not recommended. Repair in the form hepatico-jejunostomy (HJ) should be performed hepatobiliary surgeon at intervals of 46 weeks after it closes EBF. BDI is a frequent cause medico-legal actions and a substantial burden on health care costs. Most BDI can be avoided by adherence to the principles of safe cholecystectomy.

Analysis of baroreflex sensitivity during undulation pump ventricular assist device support.

PubMed

Liu, Hongjian; Shiraishi, Yasuyuki; Zhang, Xiumin; Song, Hojin; Saijo, Yoshifumi; Baba, Atsushi; Yambe, Tomoyuki; Abe, Yusuke; Imachi, Kou

2009-07-01

The aim of this study was to examine the baroreflex sensitivity (BRS), which involves the autonomic nervous system, in a goat with a chronically implanted undulation pump ventricular assist device (UPVAD). The UPVAD involved transforming the rotation of a brushless DC motor into an undulating motion by a disc attached via a special linking mechanism, and a jellyfish valve in the outflow cannula to prevent diastolic backflow. The pump was implanted into the thoracic cavity of a goat by a left thoracotomy, and the inflow and outflow cannulae were sutured to the apex of the left ventricle and to the descending aorta, respectively. The driving cable was wired percutaneously to an external controller. Electrocardiogram and hemodynamic waveforms were recorded at a sampling frequency of 1 kHz. BRS was determined when awake by the slope of the linear regression of R-R interval against mean arterial pressure changes, which were induced by the administration of methoxamine hydrochloride, both with continuous driving of the UPVAD as well as without assistance. BRS values during the UPVAD support and without assistance were 1.60 +/- 0.30 msec/mm Hg and 0.98 +/- 0.22 msec/mm Hg (n = 5, P < 0.05), respectively. BRS was significantly improved during left ventricular assistance. Therefore, UPVAD support might decrease sympathetic nerve activity and increase parasympathetic nerve activity to improve both microcirculation and organ function.

Full counting statistics in a serially coupled double quantum dot system with spin-orbit coupling

NASA Astrophysics Data System (ADS)

Wang, Qiang; Xue, Hai-Bin; Xie, Hai-Qing

2018-04-01

We study the full counting statistics of electron transport through a serially coupled double quantum dot (QD) system with spin-orbit coupling (SOC) weakly coupled to two electrodes. We demonstrate that the spin polarizations of the source and drain electrodes determine whether the shot noise maintains super-Poissonian distribution, and whether the sign transitions of the skewness from positive to negative values and of the kurtosis from negative to positive values take place. In particular, the interplay between the spin polarizations of the source and drain electrodes and the magnitude of the external magnetic field, can give rise to a gate-voltage-tunable strong negative differential conductance (NDC) and the shot noise in this NDC region is significantly enhanced. Importantly, for a given SOC parameter, the obvious variation of the high-order current cumulants as a function of the energy-level detuning in a certain range, especially the dip position of the Fano factor of the skewness can be used to qualitatively extract the information about the magnitude of the SOC.

Electromagnetic interference from welding and motors on implantable cardioverter-defibrillators as tested in the electrically hostile work site.

PubMed

Fetter, J G; Benditt, D G; Stanton, M S

1996-08-01

This study was designed to determine the susceptibility of an implanted cardioverter-defibrillator to electromagnetic interference in an electrically hostile work site environment, with the ultimate goal of allowing the patient to return to work. Normal operation of an implanted cardioverter-defibrillator depends on reliable sensing of the heart's electrical activity. Consequently, there is concern that external electromagnetic interference from external sources in the work place, especially welding equipment or motor-generator systems, may be sensed and produce inappropriate shocks or abnormal reed switch operation, temporarily suspending detection of ventricular tachycardia or ventricular fibrillation. The effects of electromagnetic interference on the operation of one type of implantable cardioverter-defibrillator (Medtronic models 7217 and 7219) was measured by using internal event counter monitoring in 10 patients operating arc welders at up to 900 A or working near 200-hp motors and 1 patient close to a locomotive starter drawing up to 400 A. The electromagnetic interference produced two sources of potential interference on the sensing circuit or reed switch operation, respectively: 1) electrical fields with measured frequencies up to 50 MHz produced by the high currents during welding electrode activation, and 2) magnetic fields produced by the current in the welding electrode and cable. The defibrillator sensitivity was programmed to the highest (most sensitive) value: 0.15 mV (model 7219) or 0.3 mV (model 7217). The ventricular tachycardia and ventricular fibrillation therapies were temporarily turned off but the detection circuits left on. None of the implanted defibrillators tested were affected by oversensing of the electric field as verified by telemetry from the detection circuits. The magnetic field from 225-A welding current produced a flux density of 1.2 G; this density was not adequate to close the reed switch, which requires approximately 10 G. Our testing at the work site revealed no electrical interference with this type of defibrillator. Patients were allowed to return to work. The following precautions should be observed by the patient: 1) maintain a minimal distance of 2 ft (61 cm) from the welding arc and cables or large motors, 2) do not exceed tested currents with the welding equipment, 3) wear insulated gloves while operating electrical equipment, 4) verify that electrical equipment is properly grounded, and 5) stop welding and leave the work area immediately if a therapy is delivered or a feeling of lightheadedness is experienced.

Cardiopulmonary Resuscitation in Adults and Children With Mechanical Circulatory Support: A Scientific Statement From the American Heart Association.

PubMed

Peberdy, Mary Ann; Gluck, Jason A; Ornato, Joseph P; Bermudez, Christian A; Griffin, Russell E; Kasirajan, Vigneshwar; Kerber, Richard E; Lewis, Eldrin F; Link, Mark S; Miller, Corinne; Teuteberg, Jeffrey J; Thiagarajan, Ravi; Weiss, Robert M; O'Neil, Brian

2017-06-13

Cardiac arrest in patients on mechanical support is a new phenomenon brought about by the increased use of this therapy in patients with end-stage heart failure. This American Heart Association scientific statement highlights the recognition and treatment of cardiovascular collapse or cardiopulmonary arrest in an adult or pediatric patient who has a ventricular assist device or total artificial heart. Specific, expert consensus recommendations are provided for the role of external chest compressions in such patients. © 2017 American Heart Association, Inc.

Cardiovascular responses to glucagon - Physiologic measurement by external recordings.

NASA Technical Reports Server (NTRS)

Byrne, M. J.; Pigott, V.; Spodick, D. H.

1972-01-01

Assessment by noninvasive polygraphic techniques of the cardiovascular responses of normal subjects to intravenous injections of glucagon and glucagon diluent. A blinding procedure which eliminated observer bias was used during the reading of tracings. Analysis of group results showed that glucagon provoked uniformly significant changes, including increase in heart rate, blood pressure, pressure-rate product, and ejection time index, and decrease in prejection period, mechanical and electromechanical systole, left ventricular ejection time, and the ratio PEP/LVET. The principal results correlated well with those of previous studies of the hemodynamic effects of glucagon.

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

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.

Successful living donor liver transplant in a child with Abernethy malformation with biliary atresia, ventricular septal defect and intrapulmonary shunting.

PubMed

Singhal, Ashish; Srivastava, Ajitabh; Goyal, Neerav; Vij, Vivek; Wadhawan, Manav; Bera, Motilal; Gupta, Subash

2009-12-01

Congenital portosystemic shunts are the anomalies in which the mesenteric venous drainage bypasses the liver and drains directly into the systemic circulation. This is a report of a rare case of LDLT in a four-yr old male child suffering with biliary atresia (post-failed Kasai procedure) associated with (i) a large congenital CEPSh from the spleno-mesentric confluence to the LHV, (ii) intrapulmonary shunts, (iii) perimembranous VSD. The left lobe graft was procured from the mother of the child. Recipient IVC and the shunt vessel were preserved during the hepatectomy, and the caval and shunt clamping were remarkably short while performing the HV and portal anastomosis. Post-operative course was uneventful; intrapulmonary shunts regressed within three months after transplantation and currently after 18 months following transplant child is doing well with normal liver functions. CEPSh has been extensively discussed and all the published cases of liver transplantation for CEPSh were reviewed.

[Pulsatile total cavopulmonary shunt for hypoplastic right heart syndrome with abnormal systemic venous return--a case report].

PubMed

Oiwa, H; Kawauchi, M; Chikada, M; Yagyu, K; Kotsuka, Y; Furuse, A

1995-01-01

A pulsatile total cavopulmonary shunt was successfully performed on a 5-year-old girl with hypoplastic right heart syndrome associated with abnormal systemic venous return; at the same time, modified mitral valve replacement was performed for mitral regurgitation. The right atrium, tricuspid valve and right ventricle were all extremely dimunitive. The diameter of the tricuspid valve was 50% of normal and the volume of the right ventricle was 8.6% of normal. In addition, there were severe subpumonary stenosis, a restrictive ventricular septal defect (VSD) and an atrial septal defect (ASD). The bilateral superior venae cavae (SVCs) and the hepatic vein drained to the left atrium, and the inferior vena cava was infrahepatically interrupted with a hemiazygos connection to the left superior vena cava. At the operation, each SVC was anastomosed end-to-side to each branch of the pulmonary artery (PA). The restrictive ventricular septal defect and stenotic subpulmonary lesion were left. The diameter of the ASD was reduced from 12 mm to 7 mm. The main PA was neither divided nor banded. The pulsatile blood flow from the left heart to the PA was regurated by a native restrictive VSD and stenotic subpulmonary lesion, and that from the right heart via the ASD was limited by reducing the size of the ASD. These described anatomic arrangements produced adequate antegrade pulsatile flow in the PA, which might prevent the development of pulmonary arteriovenous fistulae and, besides permit transfer of drainage of the hepatic vein from the left to the right atrium via the ASD in future.

Calcium-sensitive and insensitive transient outward current in rabbit ventricular myocytes.

PubMed Central

Hiraoka, M; Kawano, S

1989-01-01

1. A suction pipette whole-cell voltage-clamp technique was used to record membrane currents and potentials of isolated ventricular myocytes from rabbit hearts. 2. Transient outward current (Ito) was activated by voltage steps positive to -20 mV, increasing in amplitude with further depolarization to reach a maximum around +70 mV. The current attained its peak within 10 ms and then it inactivated for 100-200 ms. 3. A large portion of Ito still remained after the calcium current (ICa) was blocked when depolarizing pulses were applied at a frequency of 0.1 Hz or less. Therefore, this current component is referred to as calcium-insensitive Ito or It. 4. It showed voltage- and time-dependent inactivation similar to that observed in Purkinje fibres and other cardiac preparations. 5. The reversal potential of It depended on external K+ concentration, [K+]o, with a slope of 32 mV per 10-fold change in the presence of a normal [Na+]o (143 mM), while the slope was 48 mV per 10-fold change in low [Na+]o (1.0 mM). 6. It was completely inhibited by 2-4 mM-4-aminopyridine. Ito in the presence of ICa was also partially blocked by 4-aminopyridine and the remainder was abolished by 5 mM-caffeine. 7. The calcium-insensitive and caffeine-sensitive Ito differed in their decay rates as well as in their recovery time courses. The former was predominantly available at a slow pulsing rate, while the latter increased its amplitude with high-frequency depolarization. 8. The caffeine-sensitive Ito was inhibited by a blockade of ICa, by replacing Ca2+ with Sr2+, by external application of ryanodine and by internal application of EGTA. This indicates that the current is calcium-sensitive and is dependent on increased myoplasmic Ca2+ through Ca2+ influx via the sarcolemma and Ca2+ release from the sarcoplasmic reticulum. The current is therefore designated as IK, Ca. 9. The physiological functions of IK, Ca and It are indicated by their contribution to ventricular repolarization at fast and slow heart rates, respectively. PMID:2552080

Left ventricular hypertrophy with strain and aortic stenosis.

PubMed

Shah, Anoop S V; Chin, Calvin W L; Vassiliou, Vassilis; Cowell, S Joanna; Doris, Mhairi; Kwok, T'ng Choong; Semple, Scott; Zamvar, Vipin; White, Audrey C; McKillop, Graham; Boon, Nicholas A; Prasad, Sanjay K; Mills, Nicholas L; Newby, David E; Dweck, Marc R

2014-10-28

ECG left ventricular hypertrophy with strain is associated with an adverse prognosis in aortic stenosis. We investigated the mechanisms and outcomes associated with ECG strain. One hundred and two patients (age, 70 years [range, 63-75 years]; male, 66%; aortic valve area, 0.9 cm(2) [range, 0.7-1.2 cm(2)]) underwent ECG, echocardiography, and cardiovascular magnetic resonance. They made up the mechanism cohort. Myocardial fibrosis was determined with late gadolinium enhancement (replacement fibrosis) and T1 mapping (diffuse fibrosis). The relationship between ECG strain and cardiovascular magnetic resonance was then assessed in an external validation cohort (n=64). The outcome cohort was made up of 140 patients from the Scottish Aortic Stenosis and Lipid Lowering Trial Impact on Regression (SALTIRE) study and was followed up for 10.6 years (1254 patient-years). Compared with those without left ventricular hypertrophy (n=51) and left ventricular hypertrophy without ECG strain (n=30), patients with ECG strain (n=21) had more severe aortic stenosis, increased left ventricular mass index, more myocardial injury (high-sensitivity plasma cardiac troponin I concentration, 4.3 ng/L [interquartile range, 2.5-7.3 ng/L] versus 7.3 ng/L [interquartile range, 3.2-20.8 ng/L] versus 18.6 ng/L [interquartile range, 9.0-45.2 ng/L], respectively; P<0.001) and increased diffuse fibrosis (extracellular volume fraction, 27.4±2.2% versus 27.2±2.9% versus 30.9±1.9%, respectively; P<0.001). All patients with ECG strain had midwall late gadolinium enhancement (positive and negative predictive values of 100% and 86%, respectively). Indeed, late gadolinium enhancement was independently associated with ECG strain (odds ratio, 1.73; 95% confidence interval, 1.08-2.77; P=0.02), a finding confirmed in the validation cohort. In the outcome cohort, ECG strain was an independent predictor of aortic valve replacement or cardiovascular death (hazard ratio, 2.67; 95% confidence interval, 1.35-5.27; P<0.01). ECG strain is a specific marker of midwall myocardial fibrosis and predicts adverse clinical outcomes in aortic stenosis. © 2014 American Heart Association, Inc.

Value of an automatic external defibrillator printout as a diagnostic tool after successful AED use on a child.

PubMed

van Sambeeck, S J; van Gent, R; Schroër, C; Halbertsma, F J J

2013-04-22

A 6-year-old girl without any medical history experienced a drowning incident for a duration of 2 min, according to witnesses. This was followed by cardiopulmonary resuscitation, during which the automatic external defibrillator (AED) detected a shockable rhythm and subsequently delivered a single electroshock. At the time of admission, her medical history was unclear, and as her chest had been wet, it was not clear if the AED had been capable of correctly analysing the rhythm. The AED printout, however, revealed ventricular fibrillation (VF), which proved to be a primary cardiac cause at the time of the incident. This case report confirms the assumption that the AED can adequately perform rhythm analysis on children and convert VF into sinus rhythm. Moreover, the AED printout can provide information about the rhythm that is necessary for the diagnosis of an underlying cardiac disease.

The use of AEDs by police officers in the City of London. Automated external defibrillators.

PubMed

Ross, P; Nolan, J; Hill, E; Dawson, J; Whimster, F; Skinner, D

2001-08-01

The Guidelines 2000 for cardiopulmonary resuscitation recommend shock delivery to victims in ventricular fibrillation within 5 min of call receipt by the Emergency Medical Services. In an effort to achieve this goal, in some parts of the United States, police officers have been trained to use automated external defibrillators (AEDs). We undertook a 3-year pilot evaluation of the use of AEDs by City of London police (CPOL) officers. Over a period of 3 years, 147 CPOL officers were trained in the use of an AED. Four AEDs were placed on rapid response vehicles covering the City of London. An overall call-response interval target was set at 8 min. The CPOL attended 1103 (90%) of the total of 1232 calls to which they were summoned. The mean interval between the first call received and arrival of the CPOL on scene was 8.9+/-4.0 min. The CPOL applied AEDs to 25 victims, 13 of whom were initially in ventricular fibrillation; at least one shock was delivered to all 13. The interval between call reception and delivery of the first shock was 5.5+/-2.5 min. The mean interval between switching on the AED and delivery of the first shock was 24+/-12 s. Two (15%) of these victims survived to hospital discharge. This study has confirmed the feasibility of training police officers in the UK to use AEDs as first responders. The call received to arrival on scene interval should be reduced by improvements in communication between LAS and CPOL.

Physiological Effects of Early Incremental Mobilization of a Patient with Acute Intracerebral and Intraventricular Hemorrhage Requiring Dual External Ventricular Drainage.

PubMed

Kumble, Sowmya; Zink, Elizabeth K; Burch, Mackenzie; Deluzio, Sandra; Stevens, Robert D; Bahouth, Mona N

2017-08-01

Recent trials have challenged the notion that very early mobility benefits patients with acute stroke. It is unclear how cerebral autoregulatory impairments, prevalent in this population, could be affected by mobilization. The safety of mobilizing patients who have external ventricular drainage (EVD) devices for cerebrospinal fluid diversion and intracranial pressure (ICP) monitoring is another concern due to risk of device dislodgment and potential elevation in ICP. We report hemodynamic and ICP responses during progressive, device-assisted mobility interventions performed in a critically ill patient with intracerebral hemorrhage (ICH) requiring two EVDs. A 55-year-old man was admitted to the Neuroscience Critical Care Unit with an acute thalamic ICH and complex intraventricular hemorrhage requiring placement of two EVDs. Progressive mobilization was achieved using mobility technology devices. Range of motion exercises were performed initially, progressing to supine cycle ergometry followed by incremental verticalization using a tilt table. Physiological parameters were recorded before and after the interventions. All mobility interventions were completed without any adverse event or clinically detectable change in the patient's neurological state. Physiological parameters including hemodynamic variables and ICP remained within prescribed goals throughout. Progressive, device-assisted early mobilization was feasible and safe in this critically ill patient with hemorrhagic stroke when titrated by an interdisciplinary team of skilled healthcare professionals. Studies are needed to gain insight into the hemodynamic and neurophysiological responses associated with early mobility in acute stroke to identify subsets of patients who are most likely to benefit from this intervention.

Randomized Controlled Trial to Reduce Bacterial Colonization of Surgical Drains After Breast and Axillary Operations

PubMed Central

Degnim, Amy C.; Scow, Jeffrey S.; Hoskin, Tanya L.; Miller, Joyce P.; Loprinzi, Margie; Boughey, Judy C.; Jakub, James W.; Throckmorton, Alyssa; Patel, Robin; Baddour, Larry M.

2014-01-01

Objective To determine if bacterial colonization of drains can be reduced by local antiseptic interventions. Summary Background Drains are a potential source of bacterial entry into surgical wounds and may contribute to surgical site infection (SSI) after breast surgery. Methods Following IRB approval, patients undergoing total mastectomy and/or axillary lymph node dissection were randomized to standard drain care (control) or drain antisepsis (treated). Standard drain care comprised twice daily cleansing with alcohol swabs. Antisepsis drain care included 1) a chlorhexidine disc at the drain exit site and 2) irrigation of the drain bulb twice daily with dilute sodium hypochlorite (Dakin’s) solution. Cultures results of drain fluid and tubing were compared between control and antisepsis groups. Results Overall, 100 patients with 125 drains completed the study with 48 patients (58 drains) in the control group and 52 patients (67 drains) in the antisepsis group. Cultures of drain bulb fluid at one week were positive (1+ or greater growth) in 66% (38/58) of control drains compared to 21% of antisepsis drains (14/67), (p=0.0001). Drain tubing cultures demonstrated >50 CFU in 19% (8/43) of control drains versus 0% (0/53) of treated drains (p=0.004). SSI was diagnosed in 6 patients (6%) - 5 patients in the control group and 1 patient in the antisepsis group (p=0.06). Conclusions Simple and inexpensive local antiseptic interventions with a chlorhexidine disc and hypochlorite solution reduce bacterial colonization of drains. Based on these data, further study of drain antisepsis and its potential impact on SSI rate is warranted. PMID:23518704

Acute Communicating Hydrocephalus as Spinal Cord Surgery Complication in Patient with Lumbar Lipomyelocele.

PubMed

Prior, Alessandro; Severino, Mariasavina; Rossi, Andrea; Pavanello, Marco; Piatelli, Gianluca; Consales, Alessandro

2018-04-17

A lumbar lipomyelocele is a closed spinal dysraphism that can cause tethered cord syndrome. Between 5% and 15% of spinal dysraphism surgery cases are burdened with complications, the most common being wound infections or dehiscence and cerebrospinal fluid leak. Acute communicating hydrocephalus has never been described as a complication of this type of surgery. A 6-year-old girl who had undergone several surgeries in another institution for lumbar lipomyeloschisis came to our attention for a second opinion about the management of her spinal dysraphism. During the visit, she experienced sudden loss of consciousness. An emergent computed tomography scan revealed an acute communicating hydrocephalus. External ventricular drainage was performed with quick recovery of consciousness. Further craniospinal magnetic resonance imaging revealed small droplets of fat in the intracranial subarachnoid spaces and ventricular system, suggestive of rupture of the lipoma with consequent aseptic meningitis. This is the first description of acute communicating hydrocephalus as a complication of lipomyelocele surgery. We discuss the possible pathophysiologic mechanisms leading to cerebrospinal fluid dynamics alteration. Copyright © 2018 Elsevier Inc. All rights reserved.

Development of a compact portable driver for a pneumatic ventricular assist device.

PubMed

Nishinaka, Tomohiro; Taenaka, Yoshiyuki; Tatsumi, Eisuke; Ohnishi, Hiroyuki; Homma, Akihiko; Shioya, Kyoko; Mizuno, Toshihide; Tsukiya, Tomonori; Mushika, Sadahiko; Hashiguchi, Yasuhiro; Suzuki, Akira; Kitamura, Soichiro

2007-01-01

The Toyobo-National Cardiovascular Center pneumatic ventricular assist device (Toyobo-NCVC VAD) is widely used in Japan; however, the current pneumatic drivers have some drawbacks, including their large size, heavy weight, and high power consumption. These issues cause difficulty with mobility and contribute to an unsatisfactory quality of life for patients. Because it is urgently necessary to improve patients' safety and quality of life, we have developed a compact, low-noise, portable VAD driver by utilizing an electrohydraulic actuator consisting of a brushless DC motor and a regenerative pump. This unit can be actuated for as long as 2 h with two rechargeable lightweight batteries as well as with external AC power. It is compact in size (33 x 25 x 43 cm) and light in weight (13 kg), and the unit is carried on a mobile wheeled cart. In vitro testing with a Toyobo-NCVC VAD demonstrated a sufficient pumping capacity of up to 8 l/min. We conclude that this newly-developed compact portable driver can provide a better quality of life and improved safety for patients using protracted pneumatic VAD support.

Optimum Heart Rate to Minimize Pulsatile External Cardiac Power

NASA Astrophysics Data System (ADS)

Pahlevan, Niema; Gharib, Morteza

2011-11-01

The workload on the left ventricle is composed of steady and pulsatile components. Clinical investigations have confirmed that an abnormal pulsatile load plays an important role in the pathogenesis of left ventricular hypertrophy (LVH) and progression of LVH to congestive heart failure (CHF). The pulsatile load is the result of the complex dynamics of wave propagation and reflection in the compliant arterial vasculature. We hypothesize that aortic waves can be optimized to reduce the left ventricular (LV) pulsatile load. We used an in-vitro experimental approach to investigate our hypothesis. A unique hydraulic model was used for in-vitro experiments. This model has physical and dynamical properties similar to the heart-aorta system. Different compliant models of the artificial aorta were used to test the hypothesis under various aortic rigidities. Our results indicate that: i) there is an optimum heart rate that minimizes LV pulsatile power (this is in agreement with our previous computational study); ii) introducing an extra reflection site at the specific location along the aorta creates constructive wave conditions that reduce the LV pulsatile power.

Detecting occlusion inside a ventricular catheter using photoacoustic imaging through skull

NASA Astrophysics Data System (ADS)

Tavakoli, Behnoosh; Guo, Xiaoyu; Taylor, Russell H.; Kang, Jin U.; Boctor, Emad M.

2014-03-01

Ventricular catheters are used to treat hydrocephalus by diverting the excess of the cerebrospinal fluid (CSF) to the reabsorption site so as to regulate the intracranial pressure. The failure rate of these shunts is extremely high due to the ingrown tissue that blocks the CSF flow. We have studied a method to image the occlusion inside the shunt through the skull. In this approach the pulsed laser light coupled to the optical fiber illuminate the occluding tissue inside the catheter and an external ultrasound transducer is applied to detect the generated photoacoustic signal. The feasibility of this method is investigated using a phantom made of ovis aries brain tissue and adult human skull. We were able to image the target inside the shunt located 20mm deep inside the brain through about 4mm thick skull bone. This study could lead to the development of a simple, safe and non-invasive device for percutaneous restoration of patency to occluded shunts. This will eliminate the need of the surgical replacement of the occluded catheters which expose the patients to risks including hemorrhage and brain injury.

Using external lumbar CSF drainage to treat communicating external hydrocephalus in adult patients after acute traumatic or non-traumatic brain injury.

PubMed

Manet, Romain; Payen, Jean-François; Guerin, Romain; Martinez, Orianne; Hautefeuille, Serge; Francony, Gilles; Gergelé, Laurent

2017-10-01

Despite various treatments to control intracranial pressure (ICP) after brain injury, patients may present a late onset of high ICP or a poor response to medications. External lumbar drainage (ELD) can be considered a therapeutic option if high ICP is due to communicating external hydrocephalus. We aimed at describing the efficacy and safety of ELD used in a cohort of traumatic or non-traumatic brain-injured patients. In this multicentre retrospective analysis, patients had a delayed onset of high ICP after the initial injury and/or a poor response to ICP treatments. ELD was considered in the presence of radiological signs of communicating external hydrocephalus. Changes in ICP values and side effects following the ELD procedure were reported. Thirty-three patients with a median age of 51 years (25-75th percentile: 34-61 years) were admitted after traumatic (n = 22) or non-traumatic (n = 11) brain injuries. Their initial Glasgow Coma Scale score was 8 (4-11). Eight patients underwent external ventricular drainage prior to ELD. Median time to ELD insertion was 5 days (4-8) after brain insult. In all patients, ELD was dramatically effective in lowering ICP: 25 mmHg (20-31) before versus 7 mmHg (3-10) after (p < 0.001). None of the patients showed adverse effects such as pupil changes or intracranial bleeding after the procedure. One patient developed an ELD-related infection. These findings indicate that ELD may be considered potentially effective in controlling ICP, remaining safe if a firm diagnosis of communicating external hydrocephalus has been made.

Experimental Simulation of Active Control With On-line System Identification on Sound Transmission Through an Elastic Plate

NASA Technical Reports Server (NTRS)

1998-01-01

An adaptive control algorithm with on-line system identification capability has been developed. One of the great advantages of this scheme is that an additional system identification mechanism such as an additional uncorrelated random signal generator as the source of system identification is not required. A time-varying plate-cavity system is used to demonstrate the control performance of this algorithm. The time-varying system consists of a stainless-steel plate which is bolted down on a rigid cavity opening where the cavity depth was changed with respect to time. For a given externally located harmonic sound excitation, the system identification and the control are simultaneously executed to minimize the transmitted sound in the cavity. The control performance of the algorithm is examined for two cases. First, all the water was drained, the external disturbance frequency is swept with 1 Hz/sec. The result shows an excellent frequency tracking capability with cavity internal sound suppression of 40 dB. For the second case, the water level is initially empty and then raised to 3/20 full in 60 seconds while the external sound excitation is fixed with a frequency. Hence, the cavity resonant frequency decreases and passes the external sound excitation frequency. The algorithm shows 40 dB transmitted noise suppression without compromising the system identification tracking capability.

Lung physiology during ECS resuscitation of DCD donors followed by in situ assessment of lung function.

PubMed

Reoma, Junewai L; Rojas, Alvaro; Krause, Eric M; Obeid, Nabeel R; Lafayette, Nathan G; Pohlmann, Joshua R; Padiyar, Niru P; Punch, Jeffery D; Cook, Keith E; Bartlett, Robert H

2009-01-01

Extracorporeal cardiopulmonary support (ECS) of donors after cardiac death (DCD) has been shown to improve abdominal organs for transplantation. This study assesses whether pulmonary congestion occurs during ECS with the heart arrested and describes an in vivo method to assess if lungs are suitable for transplantation from DCD donors after ECS resuscitation. Cardiac arrest was induced in 30 kg pigs, followed by 10 min of warm ischemia. Cannulae were placed into the right atrium (RA) and iliac artery, and veno-arterial ECS was initiated for 90 min with lungs inflated, group 1 (n = 5) or deflated, group 2 (n = 3). Left atrial pressures were measured as a marker for pulmonary congestion. After 90 min of ECS, lung function was evaluated. Cannulae were placed into the pulmonary artery (PA) and left ventricle (LV). A second pump was included, and ECS was converted to a bi-ventricular (bi-VAD) system. The RVAD drained from the RA and pumped into the PA, and the LVAD drained the LV and pumped into the iliac. This brought the lungs back into circulation for a 1-hr assessment period. The oxygenator was turned off, and ventilation was restarted. Flows, blood gases, PA and left atrial pressures, and compliance were recorded. In both the groups, LA pressure was <15 mm Hg during ECS. During the lung assessment period, PA flows were 1.4-2.2 L/min. PO2 was >300 mm Hg, with normal PCO2. Extracorporeal cardiopulmonary support resuscitation of DCD donors is feasible and allows for assessment of function before procurement. Extracorporeal cardiopulmonary support does not cause pulmonary congestion, and the lungs retain adequate function for transplantation. Compliance correlated with lung function.

Dissolved solids in basin-fill aquifers and streams in the southwestern United States

USGS Publications Warehouse

Anning, David W.; Bauch, Nancy J.; Gerner, Steven J.; Flynn, Marilyn E.; Hamlin, Scott N.; Moore, Stephanie J.; Schaefer, Donald H.; Anderholm, Scott K.; Spangler, Lawrence E.

2007-01-01

The U.S. Geological Survey National Water-Quality Assessment Program performed a regional study in the Southwestern United States (Southwest) to describe the status and trends of dissolved solids in basin-fill aquifers and streams and to determine the natural and human factors that affect dissolved solids. Basin-fill aquifers, which include the Rio Grande aquifer system, Basin and Range basin-fill aquifers, and California Coastal Basin aquifers, are the most extensively used ground-water supplies in the Southwest. Rivers, such as the Colorado, the Rio Grande, and their tributaries, are also important water supplies, as are several smaller river systems that drain internally within the Southwest, or drain externally to the Pacific Ocean in southern California. The study included four components that characterize (1) the spatial distribution of dissolved-solids concentrations in basin-fill aquifers, and dissolved-solids concentrations, loads, and yields in streams; (2) natural and human factors that affect dissolved-solids concentrations; (3) major sources and areas of accumulation of dissolved solids; and (4) trends in dissolved-solids concentrations over time in basin-fill aquifers and streams, and the relation of trends to natural or human factors.

KSC-2010-5934

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Work platforms inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida begin to surround space shuttle Discovery, its solid rocket boosters and external fuel tank at dawn. The shuttle rolled back from Launch Pad 39A so technicians can examine the external tank and re-apply foam where 89 sensors were installed on the tank's aluminum skin for an instrumented tanking test on Dec. 17. The sensors were used to measure changes in the tank as super-cold propellants were pumped in and drained out. Data and analysis from the test will be used to determine what caused the tops of two, 21-foot-long support beams, called stringers, on the outside of the intertank to crack during fueling on Nov. 5. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Frank Michaux

A miniature microcontroller curve tracing circuit for space flight testing transistors.

PubMed

Prokop, N; Greer, L; Krasowski, M; Flatico, J; Spina, D

2015-02-01

This paper describes a novel miniature microcontroller based curve tracing circuit, which was designed to monitor the environmental effects on Silicon Carbide Junction Field Effect Transistor (SiC JFET) device performance, while exposed to the low earth orbit environment onboard the International Space Station (ISS) as a resident experiment on the 7th Materials on the International Space Station Experiment (MISSE7). Specifically, the microcontroller circuit was designed to operate autonomously and was flown on the external structure of the ISS for over a year. This curve tracing circuit is capable of measuring current vs. voltage (I-V) characteristics of transistors and diodes. The circuit is current limited for low current devices and is specifically designed to test high temperature, high drain-to-source resistance SiC JFETs. The results of each I-V data set are transmitted serially to an external telemetered communication interface. This paper discusses the circuit architecture, its design, and presents example results.

Laryngopyocele: report of a rare case and systematic review.

PubMed

Al-Yahya, Syarifah N; Baki, Marina Mat; Saad, Sakina Mohd; Azman, Mawaddah; Mohamad, Abdullah Sani

2016-01-01

A systematic review on laryngopyoceles across Ovid, PubMed, and Google Scholar database was conducted. A total of 61 papers published between 1952 and 2015 were found. Of these, 23 cases written in English, which described the number of cases, surgical approaches, resort to tracheostomy, complications, and outcomes, were shortlisted. Four cases of laryngopyoceles were managed endoscopically using a cold instrument, microdebrider, or laser. Eighteen cases were operated via an external approach, and 1 case applied both approaches. One of 4 endoscopic and 10 of 18 external approaches involved tracheostomy. The present study aimed to report a case of large mixed laryngopyocele that was successfully drained and marsupialized endoscopically using suction diathermy without requiring tracheostomy. Management using suction diathermy for excision and marsupialization of a laryngopyocele has never been reported and can be recommended as a feasible method due to its widespread availability. In the presence of a large laryngopyocele impeding the airway, tracheostomy may be averted in a controlled setting. None specified.

KSC-2010-5935

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Work platforms inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida begin to surround space shuttle Discovery, its solid rocket boosters and external fuel tank. The shuttle rolled back from Launch Pad 39A so technicians can examine the external tank and re-apply foam where 89 sensors were installed on the tank's aluminum skin for an instrumented tanking test on Dec. 17. The sensors were used to measure changes in the tank as super-cold propellants were pumped in and drained out. Data and analysis from the test will be used to determine what caused the tops of two, 21-foot-long support beams, called stringers, on the outside of the intertank to crack during fueling on Nov. 5. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Frank Michaux

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.

Vulnerability of drained and rewetted organic soils to climate change impacts and associated adaptation options

NASA Astrophysics Data System (ADS)

Renou-Wilson, Florence; Müller, Christoph; Wilson, David

2016-04-01

With 20% of the land covered with peat soils, Ireland needs to develop a deeper understanding among stakeholders of the potential vulnerability of peatlands and organic soils to climate change (both gradual and extreme events) in the context of current land use changes. The fate of carbon in organic soils is critical for predicting future greenhouse gas (GHG) concentrations in the atmosphere. While keeping carbon stock in organic soils (for example by rewetting drained sites) can be an effective mitigation measures to reduce CO2 emissions, adaptation options are also required to ensure their 'resilience'. Rewetting of drained organic soils has been initiated at several sites across the country with the aim to (i) reduce net GHG emissions at the source and/or (ii) create suitable conditions for carbon sequestration in active peatland habitats. We present here two sites: an industrial cutaway peatland and an extensive grassland over organic soil, where long-term (> 4 years) environmental and GHG flux (chamber) datasets in both drained and rewetted areas have provided information on the impact of annual weather variability on net ecosystem exchange (NEE). Statistical response functions estimated for gross primary production (GPP) and ecosystem respiration (Reco) were used to reconstruct annual CO2 balances using site-specific models driven by soil temperature, solar radiation, soil water table levels and leaf area index. The modification of some of the model parameters to fit predicted future climate scenarios for the region allowed potential changes in modelled NEE to be assessed. Both sites were, on average, an annual source of CO2 when drained (138 - 232 g C m-2 yr-1) and a sink when rewetted (ranging from -40 g C m-2 yr-1 in the ungrazed rewetted grassland to a maximum of -260 g C m-2 yr-1 in the rewetted cutaway). At both sites, soil temperatures and water table levels varied significantly between all years. Average NEE at each site displayed a very large standard deviation over the years suggesting a strong influence of external factors (weather variability) and vegetation change in some cases. Such wide variation in annual NEE values is not encountered in their natural counterparts within the same region. Under simulated moderate scenarios of (i) increased soil temperature (1° C) and (ii) deeper WT (-10cm) (both seasonal and/or annual), the rewetted areas always displayed a larger change (increase) in annual NEE compared to the drained areas. Furthermore, all rewetted sites became CO2 sources when both parameters were altered simultaneously over 4 years. Although positive feedbacks from vegetation may occur following such environmental changes, it is expected that the rewetted peatland areas will remain at risk under even moderate levels of climate change and may therefore require further intervention.

A structure-function analysis of the left ventricle

PubMed Central

Meyer, Leith C. R.; Fuller, Andrea; Haw, Anna; Mitchell, Duncan; Farrell, Anthony P.; Costello, Mary-Ann; Izwan, Adian; Badenhorst, Margaret; Maloney, Shane K.

2016-01-01

This study presents a structure-function analysis of the mammalian left ventricle and examines the performance of the cardiac capillary network, mitochondria, and myofibrils at rest and during simulated heavy exercise. Left ventricular external mechanical work rate was calculated from cardiac output and systemic mean arterial blood pressure in resting sheep (Ovis aries; n = 4) and goats (Capra hircus; n = 4) under mild sedation, followed by perfusion-fixation of the left ventricle and quantification of the cardiac capillary-tissue geometry and cardiomyocyte ultrastructure. The investigation was then extended to heavy exercise by increasing cardiac work according to published hemodynamics of sheep and goats performing sustained treadmill exercise. Left ventricular work rate averaged 0.017 W/cm3 of tissue at rest and was estimated to increase to ∼0.060 W/cm3 during heavy exercise. According to an oxygen transport model we applied to the left ventricular tissue, we predicted that oxygen consumption increases from 195 nmol O2·s−1·cm−3 of tissue at rest to ∼600 nmol O2·s−1·cm−3 during heavy exercise, which is within 90% of the oxygen demand rate and consistent with work remaining predominantly aerobic. Mitochondria represent 21-22% of cardiomyocyte volume and consume oxygen at a rate of 1,150 nmol O2·s−1·cm−3 of mitochondria at rest and ∼3,600 nmol O2·s−1·cm−3 during heavy exercise, which is within 80% of maximum in vitro rates and consistent with mitochondria operating near their functional limits. Myofibrils represent 65–66% of cardiomyocyte volume, and according to a Laplacian model of the left ventricular chamber, generate peak fiber tensions in the range of 50 to 70 kPa at rest and during heavy exercise, which is less than maximum tension of isolated cardiac tissue (120–140 kPa) and is explained by an apparent reserve capacity for tension development built into the left ventricle. PMID:27586835

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 23.1021 Section 23.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 23.1021 Section 23.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

A prospective randomized study of use of drain versus no drain after burr-hole evacuation of chronic subdural hematoma.

PubMed

Singh, Amit Kumar; Suryanarayanan, Bhaskar; Choudhary, Ajay; Prasad, Akhila; Singh, Sachin; Gupta, Laxmi Narayan

2014-01-01

Chronic subdural hematoma (CSDH) recurs after surgical evacuation in 5-30% of patients. Inserting subdural drain might reduce the recurrence rate, but is not commonly practiced. There are few prospective studies to evaluate the effect of subdural drains. A prospective randomized study to investigate the effect of subdural drains in the on recurrence rates and clinical outcome following burr-hole drainage (BHD) of CSDH was undertaken. During the study period, 246 patients with CSDH were assessed for eligibility. Among 200 patients fulfilling the eligibility criteria, 100 each were assigned to "drain group" (drain inserted into the subdural space following BHD) and "without drain group" (subdural drain was not inserted following BHD) using random allocation software. The primary end point was recurrence needing re-drainage up to a period of 6 months from surgery. Recurrence occurred in 9 of 100 patients with a drain, and 26 of 100 patients in without drain group (P = 0.002). The mortality was 5% in patients with drain and 4% in patients without drain group (P = 0.744). The medical and surgical complications were comparable between the two study groups. Use of a subdural drain after burr-hole evacuation of a CSDH reduces the recurrence rate and is not associated with increased complications.

Does release of antimicrobial agents from impregnated external ventricular drainage catheters affect the diagnosis of ventriculitis?

PubMed

Bayston, Roger; Ashraf, Waheed; Ortori, Catherine

2016-02-01

Recently concern has arisen over the effect of released antimicrobial agents from antibiotic-impregnated external ventricular drainage (EVD) catheters on the reliability of CSF culture for diagnosis of ventriculitis. The authors designed a laboratory study to investigate this possibility, and to determine whether there was also a risk of loss of bacterial viability when CSF samples were delayed in transport to the laboratory. Three types of commercially available antibiotic-impregnated EVD catheters were perfused with a suspension of bacteria (Staphylococcus epidermidis) over 21 days. Samples were analyzed for bacterial viability and for concentrations of antibiotics released from the catheters. The authors also investigated the effect on bacterial viability in samples stored at 18°C and 4°C to simulate delay in CSF samples reaching the laboratory for analysis. Bacterial viability was significantly reduced in all 3 catheter types when sampled on Day 1, but this effect was not observed in later samples. The results were reflected in stored samples, with significant loss of viability in Day 1 samples but with little further loss of viable bacteria in samples obtained after this time point. All samples stored for 18 hours showed significant loss of viable bacteria. While there were differences between the catheters, only samples taken on Day 1 showed a significant reduction in the numbers of viable bacteria after passing through the catheters. This reduction coincided with higher concentrations of antimicrobial agents in the first few hours after perfusion began. Similarly, bacterial viability declined significantly after storage of Day 1 samples, but only slightly in samples obtained thereafter. The results indicate that drugs released from these antimicrobial catheters are unlikely to affect the diagnosis of ventriculitis, as sampling for this purpose is not usually conducted in the first 24 hours of EVD.

Out-of-hospital defibrillation with automated external defibrillators: postshock analysis should be delayed.

PubMed

Blouin, D; Topping, C; Moore, S; Stiell, I; Afilalo, M

2001-09-01

The American Heart Association protocols for use of automated external defibrillators (AEDs) recommend that a rhythm analysis be done immediately after each defibrillation attempt. However, shock is often followed by electrical silence or marginally organized electrical activity before ventricular fibrillation (VF) or ventricular tachycardia (VT) recurs. The optimal timing of postshock analysis for identification of recurrent VF/VT is unknown. This study examines the time to recurrence of VF/VT after a defibrillation attempt with AED. Over an 18-month period, all tapes from patients with out-of-hospital cardiac arrest who received shocks at least once with an AED were screened for recurrent VF/VT. All cases come from a single emergency medical services system providing basic life support, defibrillation with AED, and intubation with an esophageal-tracheal twin-lumen airway device (Combitube) for a population of 633,511 individuals. Pediatric and traumatic cases were excluded. When VF/VT recurred within 3 minutes of the defibrillation attempt, rhythm strips were printed and included in the study. Two cardiology fellows, blinded to the study objectives, measured the time from defibrillation to recurrent VF/VT for each strip. Over the study period, 222 tapes from 96 patients met the inclusion criteria. Only 44 (20%) occurrences of VF/VT had recurred within 6 seconds of defibrillation, 162 (73%) at 60 seconds, and 200 (90%) at 90 seconds. Eighty percent of VF/VT recurred more than 6 seconds after defibrillation and were missed when using current American Heart Association AED protocols. Subsequent analysis should be postponed until at least 30 seconds after defibrillation. Performing 30 seconds of chest compressions after defibrillation before subsequent AED rhythm analysis would increase AED identification of VF/VT to 52%.

Diagnostic Accuracy of Commercially Available Automated External Defibrillators.

PubMed

Nishiyama, Takahiko; Nishiyama, Ako; Negishi, Masachika; Kashimura, Shin; Katsumata, Yoshinori; Kimura, Takehiro; Nishiyama, Nobuhiro; Tanimoto, Yoko; Aizawa, Yoshiyasu; Mitamura, Hideo; Fukuda, Keiichi; Takatsuki, Seiji

2015-12-01

Although automated external defibrillators (AEDs) have contributed to a better survival of out-of-hospital cardiac arrests, there have been reports of their malfunctioning. We investigated the diagnostic accuracy of commercially available AEDs using surface ECGs of ventricular fibrillation (VF), ventricular tachycardia (VT), and supraventricular tachycardia (SVT). ECGs(VF 31, VT 48, SVT 97) were stored during electrophysiological studies and transmitted to 4 AEDs, the LifePak CR Plus (CR Plus), HeartStart FR3 (FR3), and CardioLife AED-2150 (CL2150) and -9231 (CL9231), through the pad electrode cables. For VF, the CL2150 and CL9231 advised shocks in all cases, and the CR Plus and FR3 advised shocks in all but one VF case. For VTs faster than 180 bpm, the ratios for advising shocks were 79%, 36%, 89%, and 96% for the CR Plus, FR3, CL2150, and CL9231, respectively. The FR3 and CR Plus did not advise shocks for narrow QRS SVTs, whereas the CL9231 tended to treat high-rate tachycardias faster than 180 bpm even with narrow QRS complexes. The characteristics of the shock advice for the FR3 differed from that for the CL9231 (kappa coefficient [κ]=0.479, P<0.001), and the CR Plus and CL2150 had characteristics somewhere between the 2 former AEDs (κ=0.818, P<0.001). Commercially available AEDs diagnosed VF almost always correctly. For VT and SVT diagnoses, a discrepancy was evident among the 4 investigated AEDs. The differences in the arrhythmia diagnosis algorithms for differentiating SVT from VT were thought to account for these differences. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Bleeding and infection with external ventricular drainage: a systematic review in comparison with adjudicated adverse events in the ongoing Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage Phase III (CLEAR-III IHV) trial.

PubMed

Dey, Mahua; Stadnik, Agnieszka; Riad, Fady; Zhang, Lingjiao; McBee, Nichol; Kase, Carlos; Carhuapoma, J Ricardo; Ram, Malathi; Lane, Karen; Ostapkovich, Noeleen; Aldrich, Francois; Aldrich, Charlene; Jallo, Jack; Butcher, Ken; Snider, Ryan; Hanley, Daniel; Ziai, Wendy; Awad, Issam A

2015-03-01

Retrospective series report varied rates of bleeding and infection with external ventricular drainage (EVD). There have been no prospective studies of these risks with systematic surveillance, threshold definitions, or independent adjudication. To analyze the rate of complications in the ongoing Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage Phase III (CLEAR III) trial, providing a comparison with a systematic review of complications of EVD in the literature. Patients were prospectively enrolled in the CLEAR III trial after placement of an EVD for obstructive intraventricular hemorrhage and randomized to receive recombinant tissue-type plasminogen activator or placebo. We counted any detected new hemorrhage (catheter tract hemorrhage or any other distant hemorrhage) on computed tomography scan within 30 days from the randomization. Meta-analysis of published series of EVD placement was compiled with STATA software. Growing or unstable hemorrhage was reported as a cause of exclusion from the trial in 74 of 5707 cases (1.3%) screened for CLEAR III. The first 250 patients enrolled have completed adjudication of adverse events. Forty-two subjects (16.8%) experienced ≥1 new bleeds or expansions, and 6 of 250 subjects (2.4%) suffered symptomatic hemorrhages. Eleven cases (4.4%) had culture-proven bacterial meningitis or ventriculitis. Risks of bleeding and infection in the ongoing CLEAR III trial are comparable to those previously reported in EVD case series. In the present study, rates of new bleeds and bacterial meningitis/ventriculitis are very low despite multiple daily injections, blood in the ventricles, the use of thrombolysis in half the cases, and generalization to >60 trial sites.

Basic and advanced paediatric cardiopulmonary resuscitation - guidelines of the Australian and New Zealand Resuscitation Councils 2010.

PubMed

Tibballs, James; Aickin, Richard; Nuthall, Gabrielle

2012-07-01

Guidelines for basic and advanced paediatric cardiopulmonary resuscitation (CPR) have been revised by Australian and New Zealand Resuscitation Councils. Changes encourage CPR out-of-hospital and aim to improve the quality of CPR in-hospital. Features of basic CPR include: omission of abdominal thrusts for foreign body airway obstruction; commencement with chest compression followed by ventilation in a ratio of 30:2 or compression-only CPR if the rescuer is unwilling/unable to give expired-air breathing when the victim is 'unresponsive and not breathing normally'. Use of automated external defibrillators is encouraged. Features of advanced CPR include: prevention of cardiac arrest by rapid response systems; restriction of pulse palpation to 10 s to diagnosis cardiac arrest; affirmation of 15:2 compression-ventilation ratio for children and for infants other than newly born; initial bag-mask ventilation before tracheal intubation; a single direct current shock of 4 J/kg for ventricular fibrillation (VF) and pulseless ventricular tachycardia followed by immediate resumption of CPR for 2 min without analysis of cardiac rhythm and avoidance of unnecessary interruption of continuous external cardiac compressions. Monitoring of exhaled carbon dioxide is recommended to detect non-tracheal intubation, assess quality of CPR, and to help match ventilation to reduced cardiac output. The intraosseous route is recommended if immediate intravenous access is impossible. Amiodarone is strongly favoured over lignocaine for refractory VF and adrenaline over atropine for severe bradycardia, asystole and pulseless electrical activity. Family presence at resuscitation is encouraged. Therapeutic hypothermia is acceptable after resuscitation to improve neurological outcome. Extracorporeal circulatory support for in-hospital cardiac arrest may be used in equipped centres. © 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

CSF Lumbar Drainage: A Safe Surgical Option in Refractory Intracranial Hypertension Associated with Acute Posttraumatic External Hydrocephalus.

PubMed

Manet, R; Schmidt, E A; Vassal, F; Charier, D; Gergelé, L

2016-01-01

External lumbar drainage (ELD) of cerebrospinal fluid (CSF) in posttraumatic refractory intracranial hypertension (ICHT) is controversial. We report our experience of ELD in ICHT associated with acute disturbance of CSF flow within subarachnoid spaces (SASs). Four adult patients admitted to the neurointensive care unit for severe TBI who presented with secondary ICHT are retrospectively reported. When refractory to second-tier therapy, if external ventricular drainage were not possible or failed, and in the absence of an indication for craniotomy to treat a mass lesion or decompressive craniectomy, we assessed the evolution of CSF volume within cranial SAS and checked the presence of basal cisterns and the absence of tonsillar herniation to evaluate interest in and the safety of ELD. As second-tier therapy failed to lower intracranial pressure (ICP; mean ICP 37 ± 5 mmHg), and computed tomography (CT) showed abnormally enlarged cranial SAS following traumatic subarachnoid hemorrhage, patients received ELD. ICP decreased, with immediate and long-term effect (mean ICP 5 mmHg ± 2 mmHg). There were no complications to report. Acute traumatic external hydrocephalus may explain some of the specific situations of secondary increased ICP, with a "normal" CT scan, that is refractory to medical treatment. In these situations, lumbar drainage should be considered to be a safe, minimally invasive, and effective surgical option.

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 23.1021 Section 23.1021... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Oil System § 23.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 29.1021 Section 29.1021... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 27.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 27.1021 Section 27.1021... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible; and (b...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 25.1021 Section 25.1021... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 25.1021 Section 25.1021... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Oil System § 25.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 23.1021 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Oil system drains. 23.1021 Section 23.1021... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Oil System § 23.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 29.1021 Section 29.1021... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Oil System § 29.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 27.1021 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Oil system drains. 27.1021 Section 27.1021... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Oil System § 27.1021 Oil system drains. A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible; and (b...

An integrated remote sensing and GIS analysis of the Kufrah Paleoriver, Eastern Sahara

NASA Astrophysics Data System (ADS)

Ghoneim, Eman; Benedetti, Michael; El-Baz, Farouk

2012-02-01

A combined remote sensing (optical and radar imagery) and GIS (hydrologic network delineation) analysis allows mapping of the Kufrah Paleoriver of Libya and sheds light on its geomorphic evolution during the Neogene. The Kufrah system, which is now largely buried beneath the windblown sands of the Eastern Sahara, drained an area of about 236,000 km 2 in central and southern Libya. The river discharged across a large inland delta to the Al-Jaghbub depression in northern Libya, and ultimately through the Sirt Basin to the Mediterranean Sea. Radar imagery reveals buried features of the landscape including drainage divides, locations of possible stream capture, deeply-incised valleys, and the distal margins of the inland delta. Previous studies have shown that the Kufrah Paleoriver is the successor of the Sahabi River, which drained most of central Libya during the late Tertiary. Satellite imagery supports the concept of large-scale drainage rearrangement in the Quaternary, driven by tectonic subsidence that diverted streamflow and sediment discharge away from the Sahabi basin toward the inland delta of the lower Kufrah basin. Paleochannels crossing the delta suggest that at various times during the Quaternary, the Kufrah Paleoriver either drained externally through the deeply-incised Sahabi Paleochannel to the Mediterranean Sea, or drained internally to paleolakes in the Al-Jaghbub depression. Thick alluvial deposits on the delta and lake margins likely provided a major sediment source to build the Great Sand Sea, which covers the region today. The southwestern branch of the Kufrah drainage is aligned with an elongated trough that connects to the Amatinga River system in Chad. Thus the Kufrah watershed may have served as an outlet from Megalake Chad to the Mediterranean Sea during humid phases of the Neogene. If so, the combined Amatinga/Kufrah system may have served as one of the proposed natural corridors used by human and animal populations to cross the Sahara during the Pleistocene. These findings hold promise for modeling past lake levels and paleoclimates, locating groundwater sources in the region, and exploring for reservoirs of oil and natural gas in the region.

The Superior Frontal Transsulcal Approach to the Anterior Ventricular System: Exploring the Sulcal and Subcortical Anatomy Using Anatomic Dissections and Diffusion Tensor Imaging Tractography.

PubMed

Koutsarnakis, Christos; Liakos, Faidon; Kalyvas, Aristotelis V; Skandalakis, Georgios P; Komaitis, Spyros; Christidi, Fotini; Karavasilis, Efstratios; Liouta, Evangelia; Stranjalis, George

2017-10-01

To explore the superior frontal sulcus (SFS) morphology, trajectory of the applied surgical corridor, and white matter bundles that are traversed during the superior frontal transsulcal transventricular approach. Twenty normal, adult, formalin-fixed cerebral hemispheres and 2 cadaveric heads were included in the study. The topography, morphology, and dimensions of the SFS were recorded in all specimens. Fourteen hemispheres were investigated through the fiber dissection technique whereas the remaining 6 were explored using coronal cuts. The cadaveric heads were used to perform the superior frontal transsulcal transventricular approach. In addition, 2 healthy volunteers underwent diffusion tensor imaging and tractography reconstruction studies. The SFS was interrupted in 40% of the specimens studied and was always parallel to the interhemispheric fissure. The proximal 5 cm of the SFS (starting from the SFS precentral sulcus meeting point) were found to overlie the anterior ventricular system in all hemispheres. Five discrete white matter layers were identified en route to the anterior ventricular system (i.e., the arcuate fibers, the frontal aslant tract, the external capsule, internal capsule, and the callosal radiations). Diffusion tensor imaging studies confirmed the fiber tract architecture. When feasible, the superior frontal transsulcal transventricular approach offers a safe and effective corridor to the anterior part of the lateral ventricle because it minimizes brain retraction and transgression and offers a wide and straightforward working corridor. Meticulous preoperative planning coupled with a sound microneurosurgical technique are prerequisites to perform the approach successfully. Copyright © 2017 Elsevier Inc. All rights reserved.

Inaccurate treatment decisions of automated external defibrillators used by emergency medical services personnel: incidence, cause and impact on outcome.

PubMed

Calle, Paul A; Mpotos, Nicolas; Calle, Simon P; Monsieurs, Koenraad G

2015-03-01

The rhythm analysis algorithm (RAA) of automated external defibrillators (AEDs) may be deceived by many factors. In this observational study we assessed RAA accuracy in prehospital interventions. For every rhythm analysis judged to be inaccurate, we looked for causal factors and estimated the impact on outcome. In 135 consecutive patients, two physicians reviewed 837 rhythm analyses independently. When they disagreed, a third physician made the final decision. Among 148 shockable episodes, 23 (16%) were not recognized by the RAA due to external artifacts (n=7), fine ventricular fibrillation (VF; n=7), RAA error without external artifacts (n=4) or a combination of factors (n=5). In six cases the omitted/delayed shock was judged to be of clinical relevance: survival with some neurological deficit (n=4), death without regaining consciousness (n=1) and no restoration of spontaneous circulation (n=1). In 689 non-shockable episodes, the RAA decided "shockable" 25 times (4%). This wrongful decision was due to external artifacts (n=9), a concurrent shock of an internal cardioverter defibrillator (n=1), RAA error without external artifacts (n=13) or a combination of factors (n=2). Fifteen spurious shocks were delivered. As these non-shockable rhythms did not deteriorate after the shock, we assumed that no significant harm was done. Up to 16% of shockable rhythms were not detected and 4% of non-shockable rhythms were interpreted as shockable. Therefore, all AED interventions should be reviewed. Feedback to caregivers may avoid future deleterious interactions with the AED, whereas AED manufacturers may use this information to improve RAA accuracy. This approach may improve the outcome of some VF patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cardiac troponin T is necessary for normal development in the embryonic chick heart.

PubMed

England, Jennifer; Pang, Kar Lai; Parnall, Matthew; Haig, Maria Isabel; Loughna, Siobhan

2016-09-01

The heart is the first functioning organ to develop during embryogenesis. The formation of the heart is a tightly regulated and complex process, and alterations to its development can result in congenital heart defects. Mutations in sarcomeric proteins, such as alpha myosin heavy chain and cardiac alpha actin, have now been associated with congenital heart defects in humans, often with atrial septal defects. However, cardiac troponin T (cTNT encoded by gene TNNT2) has not. Using gene-specific antisense oligonucleotides, we have investigated the role of cTNT in chick cardiogenesis. TNNT2 is expressed throughout heart development and in the postnatal heart. TNNT2-morpholino treatment resulted in abnormal atrial septal growth and a reduction in the number of trabeculae in the developing primitive ventricular chamber. External analysis revealed the development of diverticula from the ventricular myocardial wall which showed no evidence of fibrosis and still retained a myocardial phenotype. Sarcomeric assembly appeared normal in these treated hearts. In humans, congenital ventricular diverticulum is a rare condition, which has not yet been genetically associated. However, abnormal haemodynamics is known to cause structural defects in the heart. Further, structural defects, including atrial septal defects and congenital diverticula, have previously been associated with conduction anomalies. Therefore, to provide mechanistic insights into the effect that cTNT knockdown has on the developing heart, quantitative PCR was performed to determine the expression of the shear stress responsive gene NOS3 and the conduction gene TBX3. Both genes were differentially expressed compared to controls. Therefore, a reduction in cTNT in the developing heart results in abnormal atrial septal formation and aberrant ventricular morphogenesis. We hypothesize that alterations to the haemodynamics, indicated by differential NOS3 expression, causes these abnormalities in growth in cTNT knockdown hearts. In addition, the muscular diverticula reported here suggest a novel role for mutations of structural sarcomeric proteins in the pathogenesis of congenital cardiac diverticula. From these studies, we suggest TNNT2 is a gene worthy of screening for those with a congenital heart defect, particularly atrial septal defects and ventricular diverticula. © 2016 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

Timing of Re-Transfusion Drain Removal Following Total Knee Replacement

PubMed Central

Leeman, MF; Costa, ML; Costello, E; Edwards, D

2006-01-01

INTRODUCTION The use of postoperative drains following total knee replacement (TKR) has recently been modified by the use of re-transfusion drains. The aim of our study was to investigate the optimal time for removal of re-transfusion drains following TKR. PATIENTS AND METHODS The medical records of 66 patients who had a TKR performed between October 2003 and October 2004 were reviewed; blood drained before 6 h and the total volume of blood drained was recorded. RESULTS A total of 56 patients had complete records of postoperative drainage. The mean volume of blood collected in the drain in the first 6 h was 442 ml. The mean total volume of blood in the drain was 595 ml. Therefore, of the blood drained, 78% was available for transfusion. CONCLUSION Re-transfusion drains should be removed after 6 h, when no further re-transfusion is permissible. PMID:16551400

A Brief History of Two Common Surgical Drains.

PubMed

Meyerson, Joseph M

2016-01-01

The use of surgical drains is commonplace in all types of surgical procedures, and rarely do we take the time to contemplate or investigate the origins of these critical devices. Every surgeon should be familiar with the Jackson-Pratt drain and Blake drain, 2 of the most frequently used closed suction, negative-pressure drainage devices in surgery. These drains are used throughout the body in a wide variety of surgical procedures. The development and differences between these 2 devices are seldom known by the practicing surgeon. In this article, we delve into the ancient history of drains, the creation and alterations of the closed suction, negative-pressure drain that paved the way for the Jackson-Pratt and Blake drain. Finally, we will discuss the variety of reservoirs that attach to these drains and the origin of the well-known adage of when to pull a drain.

A study of the complications of small bore 'Seldinger' intercostal chest drains.

PubMed

Davies, Helen E; Merchant, Shairoz; McGown, Anne

2008-06-01

Use of small bore chest drains (<14F), inserted via the Seldinger technique, has increased globally over the last few years. They are now used as first line interventions in most acute medical situations when thoracostomy is required. Limited data are available on the associated complications. In this study, the frequency of complications associated with 12F chest drains, inserted using the Seldinger technique, was quantified. A retrospective case note audit was performed of consecutive patients requiring pleural drainage over a 12-month period. One hundred consecutive small bore Seldinger (12F) chest drain insertions were evaluated. Few serious complications occurred. However, 21% of the chest drains were displaced ('fell out') and 9% of the drains became blocked. This contributed to high morbidity rates, with 13% of patients requiring repeat pleural procedures. The frequency of drain blockage in pleural effusion was reduced by administration of regular normal saline drain flushes (odds ratio for blockage in flushed drains compared with non-flushed drains 0.04, 95% CI: 0.01-0.37, P < 0.001). Regular chest drain flushes are advocated in order to reduce rates of drain blockage, and further studies are needed to determine optimal fixation strategies that may reduce associated patient morbidity.

Comparison of a large and small-calibre tube drain for managing spontaneous pneumothoraces.

PubMed

Benton, Ian J; Benfield, Grant F A

2009-10-01

To compare treatment success of large- and small-bore chest drains in the treatment of spontaneous pneumothoraces the case-notes were reviewed of those admitted to our hospital with a total of 73 pneumothoraces and who were treated by trainee doctors of varying experience. Both a large- and a small-bore intercostal tube drain system were in use during the two-year period reviewed. Similar pneumothorax profile and numbers treated with both drains were recorded, resulting in a similar drain time and numbers of successful and failed re-expansion of pneumothoraces. Successful pneumothorax resolution was the same for both drain types and the negligible tube drain complications observed with the small-bore drain reflected previously reported experiences. However the large-bore drain was associated with a high complication rate (32%) with more infectious complications (24%). The small-bore drain was prone to displacement (21%). There was generally no evidence of an increased failure and morbidity, reflecting poorer expertise, in the non-specialist trainees managing the pneumothoraces. A practical finding however was that in those large pneumothoraces where re-expansion failed, the tip of the drain had not been sited at the apex of the pleural cavity irrespective of the drain type inserted.

Automated external defibrillators and simulated in-hospital cardiac arrests.

PubMed

Rossano, Joseph W; Jefferson, Larry S; Smith, E O'Brian; Ward, Mark A; Mott, Antonio R

2009-05-01

To test the hypothesis that pediatric residents would have shorter time to attempted defibrillation using automated external defibrillators (AEDs) compared with manual defibrillators (MDs). A prospective, randomized, controlled trial of AEDs versus MDs was performed. Pediatric residents responded to a simulated in-hospital ventricular fibrillation cardiac arrest and were randomized to using either an AED or MD. The primary end point was time to attempted defibrillation. Sixty residents, 21 (35%) interns, were randomized to 2 groups (AED = 30, MD = 30). Residents randomized to the AED group had a significantly shorter time to attempted defibrillation [median, 60 seconds (interquartile range, 53 to 71 seconds)] compared with those randomized to the MD group [median, 103 seconds (interquartile range, 68 to 288 seconds)] (P < .001). All residents in the AED group attempted defibrillation at <5 minutes compared with 23 (77%) in the MD group (P = .01). AEDs improve the time to attempted defibrillation by pediatric residents in simulated cardiac arrests. Further studies are needed to help determine the role of AEDs in pediatric in-hospital cardiac arrests.

Multisystem dating of modern river detritus from Tajikistan and China: Implications for crustal evolution and exhumation of the Pamir

USGS Publications Warehouse

Barbara Carappa,; Mustapha, F.S.; Cosca, Michael A.; Gehrels, George E.; Schoenbhohm, L; Sobel, E.; DeCelles.P.,; Russell, Joellen; Goodman, Paul

2014-01-01

The Pamir is the western continuation of Tibet and the site of some of the highest mountains on Earth, yet comparatively little is known about its crustal and tectonic evolution and erosional history. Both Tibet and the Pamir are characterized by similar terranes and sutures that can be correlated along strike, although the details of such correlations remain controversial. The erosional history of the Pamir with respect to Tibet is significantly different as well: Most of Tibet has been characterized by internal drainage and low erosion rates since the early Cenozoic; in contrast, the Pamir is externally drained and topographically more rugged, and it has a strongly asymmetric drainage pattern. Here, we report 700 new U-Pb and Lu-Hf isotope determinations and >300 40Ar/39Ar ages from detrital minerals derived from rivers in China draining the northeastern Pamir and >1000 apatite fission-track (AFT) ages from 12 rivers in Tajikistan and China draining the northeastern, central, and southern Pamir. U-Pb ages from rivers draining the northeastern Pamir are Mesozoic to Proterozoic and show affinity with the Songpan-Ganzi terrane of northern Tibet, whereas rivers draining the central and southern Pamir are mainly Mesozoic and show some affinity with the Qiangtang terrane of central Tibet. The εHf values are juvenile, between 15 and −5, for the northeastern Pamir and juvenile to moderately evolved, between 10 and −40, for the central and southern Pamir. Detrital mica 40Ar/39Ar ages for the northeastern Pamir (eastern drainages) are generally older than ages from the central and southern Pamir (western drainages), indicating younger or lower-magnitude exhumation of the northeastern Pamir compared to the central and southern Pamir. AFT data show strong Miocene–Pliocene signals at the orogen scale, indicating rapid erosion at the regional scale. Despite localized exhumation of the Mustagh-Ata and Kongur-Shan domes, average erosion rates for the northeastern Pamir are up to one order of magnitude lower than erosion rates recorded by the central and southern Pamir. Deeper exhumation of the central and southern Pamir is associated with tectonic exhumation of central Pamir domes. Deeper exhumation coincides with western and asymmetric drainages and with higher precipitation today, suggesting an orographic effect on exhumation. A younging-southward trend of cooling ages may reflect tectonic processes. Overall, cooling ages derived from the Pamir are younger than ages recorded in Tibet, indicating younger and higher magnitudes of erosion in the Pamir.

Failure of communication and capture: The perils of temporary unipolar pacing system.

PubMed

Sahinoglu, Efe; Wool, Thomas J; Wool, Kenneth J

2015-06-01

We present a case of a patient with pacemaker dependence secondary to complete heart block who developed loss of capture of her temporary pacemaker. Patient developed torsades de pointes then ventricular fibrillation, requiring CPR and external cardioversion. After patient was stabilized, it was noticed that loss of capture of pacemaker corresponded with nursing care, when the pulse generator was lifted off patient׳s chest wall, and that patient׳s temporary pacing system had been programmed to unipolar mode without knowledge of attending cardiologist. This case highlights the importance of communication ensuring all caregivers are aware of mode of the temporary pacing system.

Chest Drain Fall-Out Rate According to Suturing Practices: A Retrospective Direct Comparison.

PubMed

Asciak, Rachelle; Addala, Dinesh; Karimjee, Juzer; Rana, Maaz Suhail; Tsikrika, Stamatoula; Hassan, Maged Fayed; Mercer, Rachel Mary; Hallifax, Robert John; Wrightson, John Matthew; Psallidas, Ioannis; Benamore, Rachel; Rahman, Najib Mahboob

2018-06-14

Chest drains often become displaced and require replacement, adding unnecessary risks to patients. Simple measures such as suturing of the drain may reduce fall-out rates; however, there is no direct data to demonstrate this and no standardized recommended practice that is evidence based. The study aimed to analyze the rate of chest drain fall out according to suturing practice. Retrospective analysis of all chest drain insertions (radiology and pleural teams) in 2015-2016. Details of chest drain fall out were collected from patient electronic records. Drain "fall out" was pre-hoc defined as the drain tip becoming dislodged outside the pleural cavity unintentionally before a clinical decision was taken to remove the drain. A total of 369 chest drains were inserted: sutured (n = 106, 28.7%; 44 male [41.5%], median age 74 [interquartile range (IQR) 21] years), and unsutured (n = 263, 71.3%; 139 male [52.9%], median age 68 [IQR 21] years). Of the sutured drains, 7 (6.6%) fell out after a mean of 3.3 days (SD 2.6) compared to 39 (14.8%; p = 0.04) unsutured drains falling out after a mean of 2.7 days (SD 2.0; p = 0.8). Within the limits of this retrospective analysis, these results -suggest that suturing of drains is associated with lower fall-out rates. © 2018 S. Karger AG, Basel.

The macroscopic vascular anatomy of the equine ethmoidal area.

PubMed

Bell, B T; Baker, G J; Abbott, L C; Foreman, J H; Kneller, S K

1995-03-01

The vascular anatomy of the ethmoidal area in six normal horses and two normal ponies was studied using vascular-corrosion casts. The major arterial supply to the ethmoidal area stems from an intracranial source. The internal and external ethmoidal arteries anastomose on the rostral intracranial surface of the cribriform plate to form the arterial ethmoidal rete which arborizes and passes through the perforations of the cribriform plate to supply the ethmoid labyrinth. A minor arterial supply to the ventral portion of the ethmoid labyrinth stems from a small caudal nasal branch of the sphenopalatine artery. Multiple parallel venules drain the ethmoid labyrinth rostrally to its apex then join the venous drainage from the surrounding sinuses.

Might digital drains speed up the time to thoracic drain removal?

PubMed

Afoke, Jonathan; Tan, Carol; Hunt, Ian; Zakkar, Mustafa

2014-07-01

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: might digital drains speed up the time to thoracic drain removal in terms of time till chest drain removal, hospital stay and overall cost? A total of 296 papers were identified as a result of the search as described below. Of these, five papers provided the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of the papers are tabulated. A literature search revealed that several single-centre prospective randomized studies have shown significantly earlier removal of chest drains with digital drains ranging between 0.8 and 2.1 days sooner. However, there was heterogeneity in studies in the management protocol of chest drains in terms of the use of suction, number of drains and assessment for drain removal. Some protocols such as routinely keeping drains irrespective of the presence of air leak or drain output may have skewed results. Differences in exclusion criteria and protocols for discharging home with portable devices may have biased results. Due to heterogeneity in the management protocol of chest drains, there is conflicting evidence regarding hospital stay. The limited data on cost suggest that there may be significantly lower postoperative costs in the digital drain group. All the studies were single-centre series generally including patients with good preoperative lung function tests. Further larger studies with more robust chest drain management protocols are required especially to assess length of hospital stay, cost and whether the results are applicable to a larger patient population. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Charge plasma based source/drain engineered Schottky Barrier MOSFET: Ambipolar suppression and improvement of the RF performance

NASA Astrophysics Data System (ADS)

Kale, Sumit; Kondekar, Pravin N.

2018-01-01

This paper reports a novel device structure for charge plasma based Schottky Barrier (SB) MOSFET on ultrathin SOI to suppress the ambipolar leakage current and improvement of the radio frequency (RF) performance. In the proposed device, we employ dual material for the source and drain formation. Therefore, source/drain is divided into two parts as main source/drain and source/drain extension. Erbium silicide (ErSi1.7) is used as main source/drain material and Hafnium metal is used as source/drain extension material. The source extension induces the electron plasma in the ultrathin SOI body resulting reduction of SB width at the source side. Similarly, drain extension also induces the electron plasma at the drain side. This significantly increases the SB width due to increased depletion at the drain end. As a result, the ambipolar leakage current can be suppressed. In addition, drain extension also reduces the parasitic capacitances of the proposed device to improve the RF performance. The optimization of length and work function of metal used in the drain extension is performed to achieve improvement in device performance. Moreover, the proposed device makes fabrication simpler, requires low thermal budget and free from random dopant fluctuations.

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.

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

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.

Right ventricular involvement in cardiac sarcoidosis demonstrated with cardiac magnetic resonance

PubMed Central

van Geuns, Robert‐Jan; Ainslie, Gillian; Ector, Joris; Heidbuchel, Hein; Crijns, Harry J.G.M.

2017-01-01

Abstract Aims Cardiac involvement in sarcoidosis is reported in up to 30% of patients. Left ventricular involvement demonstrated by contrast‐enhanced cardiac magnetic resonance has been well validated. We sought to determine the prevalence and distribution of right ventricular late gadolinium enhancement in patients diagnosed with pulmonary sarcoidosis. Methods and results We prospectively evaluated 87 patients diagnosed with pulmonary sarcoidosis with contrast‐enhanced cardiac magnetic resonance for right ventricular involvement. Pulmonary artery pressures were non‐invasively evaluated with Doppler echocardiography. Patient characteristics were compared between the groups with and without right ventricular involvement, and right ventricular enhancement was correlated with pulmonary hypertension, ventricular mass, volume, and systolic function. Left ventricular late gadolinium enhancement was demonstrated in 30 patients (34%). Fourteen patients (16%) had right ventricular late gadolinium enhancement, with sole right ventricular enhancement in only two patients. The pattern of right ventricular enhancement consisted of right ventricular outflow tract enhancement in 1 patient, free wall enhancement in 8 patients, ventricular insertion point enhancement in 10 patients, and enhancement of the right side of the interventricular septum in 11 patients. Pulmonary arterial hypertension correlated with the presence of right ventricular enhancement (P < 0.001). Right ventricular enhancement correlated with systolic ventricular dysfunction (P < 0.001), hypertrophy (P = 0.001), and dilation (P < 0.001). Conclusions Right ventricular enhancement was present in 16% of patients diagnosed with pulmonary sarcoidosis and in 48% of patients with left ventricular enhancement. The presence of right ventricular enhancement correlated with pulmonary arterial hypertension, right ventricular systolic dysfunction, hypertrophy, and dilation. PMID:29154434

3. DRAINING & DRYING BUILDING, REINFORCED CONCRETE MUSHROOM COLUMNS WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. DRAINING & DRYING BUILDING, REINFORCED CONCRETE MUSHROOM COLUMNS WITH DROP PANELS SUPPORTING DRAINING BINS (IRON VALVES OF DRAINING BINS ARE EMBEDDED IN THE CEILING), VIEW LOOKING WEST - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

Evisceration of Appendix through the Drain Site: A Rare Case Report.

PubMed

Ravishankaran, Praveen; Rajamani, A

2013-06-01

Placing a drain after surgery is a usual procedure in any emergency abdominal operation. The drain is removed as soon as its purpose of draining the intraabdominal collection in served. Evisceration of intraabdominal organs through the drain site is a rare occurance. This case report is about an 12 year old girl who was admitted with blunt trauma abdomen. After completion of emergency laparotomy a drain was placed in the right lower quadrant. When the drain was removed on the 6th post operative day, the appendix eviscerated out of the drain site. The wound was extended a little and an appendectomy was done. This case is presented for its rarity as only two similar instances have been reported in literature so far.

A forgotten retained drain inside a knee for 10 years: A case report.

PubMed

Koaban, Saeed; Alatassi, Raheef; Alogayyel, Nawaf

2018-05-29

Surgical drains are inserted into the wound after an arthroscopic knee procedure mainly to decrease fluid collection after the operation. The use of postoperative surgical drains remains controversial. This report presents a rare case of a forgotten retained drain that was accidentally found inside a knee 10 years after an arthroscopic procedure. The drain was removed without any complications. A retained and broken drain during removal is a very rare and preventable complication that can be stressful for both the patient and surgeon. Most of the literature supports that retained drains in the soft tissues do not affect long-term outcomes, but if the drain fragment is in the intra-articular area, it might cause complications. Furthermore, there are several preventive measures to avoid retained surgical drains. By reporting this case of a forgotten drain retained inside a knee for approximately 10 years, we aim to illustrate the potential risk of leaving a drain inside the joint following an arthroscopic procedure. Furthermore, we advise that surgeons maintain a high index of suspicion for iatrogenic complications when a patient continues to complain about unexplained pain at the surgical site. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Congenital Vitelline Band Causing Intestinal Obstruction in an Adult with a Double Inferior Vena Cava

PubMed Central

Pussepitiya, Kumari; Samarasinghe, Bandula; Wickramasinghe, Nuwan

2016-01-01

Introduction. Vitelline artery remnants are rare causes of intra-abdominal bands leading to bowel obstruction. These bands may be associated with Meckel's diverticulum. Double inferior vena cava (IVC) is a rare presentation and is usually identified incidentally. Case Presentation. A sixty-year-old male presented with progressive vomiting for five days and he was clinically diagnosed with intestinal obstruction. Plain X-ray abdomen showed evidence of small bowel obstruction. CT scan of the abdomen revealed dilated small bowel loops with a small outpouching in the distal ileum with a band like structure attached to it. In the CT, left sided patent IVC draining into the left renal vein was identified. Left external iliac vein was in continuity with the left IVC. Left internal iliac vein was draining into the right IVC. Exploratory laparotomy revealed a Meckel's diverticulum with a band identified as the vitelline remnant attached to its apex and inserting at the anterior abdominal wall near the umbilicus. Discussion. Meckel's diverticulum with vitelline bands, although rare, should be borne in mind in adult patients with intestinal obstruction. Identification of this anomaly can be difficult in imaging studies. Presence of double IVC should be mentioned in the imaging findings to prevent possible catastrophic complications during surgery. PMID:27843667

Design and analysis of optimised class E power amplifier using shunt capacitance in the output structure

NASA Astrophysics Data System (ADS)

Hayati, Mohsen; Roshani, Sobhan; Zirak, Ali Reza

2017-05-01

In this paper, a class E power amplifier (PA) with operating frequency of 1 MHz is presented. MOSFET non-linear drain-to-source parasitic capacitance, linear external capacitance at drain-to-source port and linear shunt capacitance in the output structure are considered in design theory. One degree of freedom is added to the design of class E PA, by assuming the shunt capacitance in the output structure in the analysis. With this added design degree of freedom it is possible to achieve desired values for several parameters, such as output voltage, load resistance and operating frequency, while both zero voltage and zero derivative switching (ZVS and ZDS) conditions are satisfied. In the conventional class E PA, high value of peak switch voltage results in limitations for the design of amplifier, while in the presented structure desired specifications could be achieved with the safe margin of peak switch voltage. The results show that higher operating frequency and output voltage can also be achieved, compared to the conventional structure. PSpice software is used in order to simulate the designed circuit. The presented class E PA is designed, fabricated and measured. The measured results are in good agreement with simulation and theory results.

Evaluation of inlet sampling integrity on NSF/NCAR airborne platforms

NASA Astrophysics Data System (ADS)

Campos, T. L.; Stith, J. L.; Stephens, B. B.; Romashkin, P.

2017-12-01

An inlet test project was conducted during IDEAS-IV-GV (2013), to evaluate the sampling integrity of two inlet designs. Use of a single CO2 sensor provided a high precision detector and a large difference in the mean cabin and external concentrations (500-700 ppmv in the cabin). The original HIAPER Modular InLet (HIMIL) is comprised of a tapered flow straightening flow through `cigar' mounted to a strut. The cigar center sampling line sits 12" from the fuselage skin. An o-ring seals the feedthrough plate coupling sampling lines from the strut into the cigar. However, there is no seal to prevent air inside the strut from seeping out around the cigar body. A pressure-equalizing drain hole in the strut access panel; it was positioned at an approximate distance of 4" from the fuselage to ensure that air from any source that drained out of the strut was confined to a low release point. A second aft-facing inlet design was also evaluated. The sampling center line was moved farther from the fuselage at a height of 16". A similar approach was also applied to sampling locations on the C-130 in 2015. The results of these tests and recommendations for best practices will be presented.

Developing NDE Techniques for Large Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Parker, Don; Starr, Stan; Arens, Ellen

2011-01-01

The Shuttle Program requires very large cryogenic ground storage tanks in which to store liquid oxygen and hydrogen. The existing Pads A and B Launch Complex-39 tanks, which will be passed onto future launch programs, are 45 years old and have received minimal refurbishment and only external inspections over the years. The majority of the structure is inaccessible without a full system drain of cryogenic liquid and granular insulation in the annular region. It was previously thought that there was a limit to the number of temperature cycles that the tanks could handle due to possible insulation compaction before undergoing a costly and time consuming complete overhaul; therefore the tanks were not drained and performance issues with these tanks, specifically the Pad B liquid hydrogen tank, were accepted. There is a needind an opportunity, as the Shuttle program ends and work to upgrade the launch pads progresses, to develop innovative non-destructive evaluation (NDE) techniques to analyze the current tanks. Techniques are desired that can aid in determining the extent of refurbishment required to keep the tanks in service for another 20+ years. A nondestructive technique would also be a significant aid in acceptance testing of new and refurbished tanks, saving significant time and money, if corrective actions can be taken before cryogen is introduced to the systems.

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.

Right ventricular involvement in cardiac sarcoidosis demonstrated with cardiac magnetic resonance.

PubMed

Smedema, Jan-Peter; van Geuns, Robert-Jan; Ainslie, Gillian; Ector, Joris; Heidbuchel, Hein; Crijns, Harry J G M

2017-11-01

Cardiac involvement in sarcoidosis is reported in up to 30% of patients. Left ventricular involvement demonstrated by contrast-enhanced cardiac magnetic resonance has been well validated. We sought to determine the prevalence and distribution of right ventricular late gadolinium enhancement in patients diagnosed with pulmonary sarcoidosis. We prospectively evaluated 87 patients diagnosed with pulmonary sarcoidosis with contrast-enhanced cardiac magnetic resonance for right ventricular involvement. Pulmonary artery pressures were non-invasively evaluated with Doppler echocardiography. Patient characteristics were compared between the groups with and without right ventricular involvement, and right ventricular enhancement was correlated with pulmonary hypertension, ventricular mass, volume, and systolic function. Left ventricular late gadolinium enhancement was demonstrated in 30 patients (34%). Fourteen patients (16%) had right ventricular late gadolinium enhancement, with sole right ventricular enhancement in only two patients. The pattern of right ventricular enhancement consisted of right ventricular outflow tract enhancement in 1 patient, free wall enhancement in 8 patients, ventricular insertion point enhancement in 10 patients, and enhancement of the right side of the interventricular septum in 11 patients. Pulmonary arterial hypertension correlated with the presence of right ventricular enhancement (P < 0.001). Right ventricular enhancement correlated with systolic ventricular dysfunction (P < 0.001), hypertrophy (P = 0.001), and dilation (P < 0.001). Right ventricular enhancement was present in 16% of patients diagnosed with pulmonary sarcoidosis and in 48% of patients with left ventricular enhancement. The presence of right ventricular enhancement correlated with pulmonary arterial hypertension, right ventricular systolic dysfunction, hypertrophy, and dilation. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

The overloaded right heart and ventricular interdependence.

PubMed

Naeije, Robert; Badagliacca, Roberto

2017-10-01

The right and the left ventricle are interdependent as both structures are nested within the pericardium, have the septum in common and are encircled with common myocardial fibres. Therefore, right ventricular volume or pressure overloading affects left ventricular function, and this in turn may affect the right ventricle. In normal subjects at rest, right ventricular function has negligible interaction with left ventricular function. However, the right ventricle contributes significantly to the normal cardiac output response to exercise. In patients with right ventricular volume overload without pulmonary hypertension, left ventricular diastolic compliance is decreased and ejection fraction depressed but without intrinsic alteration in contractility. In patients with right ventricular pressure overload, left ventricular compliance is decreased with initial preservation of left ventricular ejection fraction, but with eventual left ventricular atrophic remodelling and altered systolic function. Breathing affects ventricular interdependence, in healthy subjects during exercise and in patients with lung diseases and altered respiratory system mechanics. Inspiration increases right ventricular volumes and decreases left ventricular volumes. Expiration decreases both right and left ventricular volumes. The presence of an intact pericardium enhances ventricular diastolic interdependence but has negligible effect on ventricular systolic interdependence. On the other hand, systolic interdependence is enhanced by a stiff right ventricular free wall, and decreased by a stiff septum. Recent imaging studies have shown that both diastolic and systolic ventricular interactions are negatively affected by right ventricular regional inhomogeneity and prolongation of contraction, which occur along with an increase in pulmonary artery pressure. The clinical relevance of these observations is being explored. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 29.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 29.999 Section 29.999... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System Components § 29.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

14 CFR 27.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 27.999 Section 27.999... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System Components § 27.999 Fuel system drains. (a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

21 CFR 868.5995 - Tee drain (water trap).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

A mathematical model to optimize the drain phase in gravity-based peritoneal dialysis systems.

PubMed

Akonur, Alp; Lo, Ying-Cheng; Cizman, Borut

2010-01-01

Use of patient-specific drain-phase parameters has previously been suggested to improve peritoneal dialysis (PD) adequacy. Improving management of the drain period may also help to minimize intraperitoneal volume (IPV). A typical gravity-based drain profile consists of a relatively constant initial fast-flow period, followed by a transition period and a decaying slow-flow period. That profile was modeled using the equation VD(t) = (V(D0) - Q(MAX) x t) xphi + (V(D0) x e(-alphat)) x (1 - phi), where V(D)(t) is the time-dependent dialysate volume; V(D0), the dialysate volume at the start of the drain; Q(MAX), the maximum drain flow rate; alpha, the exponential drain constant; and phi, the unit step function with respect to the flow transition. We simulated the effects of the assumed patient-specific maximum drain flow (Q(MAX)) and transition volume (psi), and the peritoneal volume percentage when transition occurs,for fixed device-specific drain parameters. Average patient transport parameters were assumed during 5-exchange therapy with 10 L of PD solution. Changes in therapy performance strongly depended on the drain parameters. Comparing 400 mL/85% with 200 mL/65% (Q(MAX/psi), drain time (7.5 min vs. 13.5 min) and IPV (2769 mL vs. 2355 mL) increased when the initial drain flow was low and the transition quick. Ultrafiltration and solute clearances remained relatively similar. Such differences were augmented up to a drain time of 22 minutes and an IPV of more than 3 L when Q(MAX) was 100 mL/min. The ability to model individual drain conditions together with water and solute transport may help to prevent patient discomfort with gravity-based PD. However, it is essential to note that practical difficulties such as displaced catheters and obstructed flow paths cause variability in drain characteristics even for the same patient, limiting the clinical applicability of this model.

Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment.

PubMed

Dzieciol, Monika; Schornsteiner, Elisa; Muhterem-Uyar, Meryem; Stessl, Beatrix; Wagner, Martin; Schmitz-Esser, Stephan

2016-04-16

Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions on the bacterial composition of the microbiota in biofilms. Copyright © 2016. Published by Elsevier B.V.

[Outpatient Drain Management in Patients with Clinically Relevant Postoperative Pancreatic Fistula (CR-POPF) - Current Status in Germany].

PubMed

Hempel, Sebastian; Püttmann, Pamela; Kahlert, Christoph; Seifert, Lena; Mees, Sören Torge; Welsch, Thilo; Weitz, Jürgen; Distler, Marius

2018-06-01

Postoperative pancreatic fistula (POPF) is a common complication after pancreatic surgery and is associated with extended hospitalisation, increased medical costs, and reduced quality of life. The aim of the present study was to assess the treatment of POPF in Germany, with a special focus on outpatient drain management in patients with clinically relevant POPF (CR-POPF). A questionnaire evaluating postoperative management once a CR-POPF is diagnosed - especially focusing on ambulatory drain management - was developed and sent to 211 German hospitals performing > 12 pancreatic operations per year. Statistical analysis was carried out using SPSS 21. The final response rate was 62% (n = 131). Outpatient drainage management is performed by most of the responding hospitals (n = 100, 76.3%). However, 30% of hospitals (n = 40) perform outpatient treatment only in 5% of their cases with clinically relevant POPF. There was no correlation between case load of the pancreatic centres and frequency of outpatient drain management. In general, discharge criteria for patients with drained POPF (n = 98, 74.8%), the drain management itself (n = 95, 72.5%) and criteria for drain removal (n = 74, 56.5%) are not standardised but made individually. In centres with standardised drain management criteria for drain removal, these criteria were drain volume < 20 ml (29.8%), no fluid collection (25.2%), no elevation of drain amylase/lipase (25.2%) and no specific symptoms (22.1%). This is the first survey in Germany evaluating outpatient drain management in patients with CR-POPF. Although the data in the literature are rare, the majority of German pancreatic surgeons perform outpatient drain management. However, discharge criteria, outpatient care and drain removal are standardised in only the minority of centres. Therefore, we recommend the evaluation of discharge criteria and a management algorithm for patients with drained CR-POPF to improve the perioperative course. Georg Thieme Verlag KG Stuttgart · New York.

Effects of Frequent Hemodialysis on Ventricular Volumes and Left Ventricular Remodeling

PubMed Central

Greene, Tom; Chertow, Glenn M.; Kliger, Alan S.; Stokes, John B.; Beck, Gerald J.; Daugirdas, John T.; Kotanko, Peter; Larive, Brett; Levin, Nathan W.; Mehta, Ravindra L.; Rocco, Michael; Sanz, Javier; Yang, Phillip C.; Rajagopalan, Sanjay

2013-01-01

Summary Background and objectives Higher left ventricular volume is associated with death in patients with ESRD. This work investigated the effects of frequent hemodialysis on ventricular volumes and left ventricular remodeling. Design, setting, participants, & measurements The Frequent Hemodialysis Network daily trial randomized 245 patients to 12 months of six times per week versus three times per week in-center hemodialysis; the Frequent Hemodialysis Network nocturnal trial randomized 87 patients to 12 months of six times per week nocturnal hemodialysis versus three times per week predominantly home-based hemodialysis. Left and right ventricular end systolic and diastolic volumes, left ventricular mass, and ejection fraction at baseline and end of the study were ascertained by cardiac magnetic resonance imaging. The ratio of left ventricular mass/left ventricular end diastolic volume was used as a surrogate marker of left ventricular remodeling. In each trial, the effect of frequent dialysis on left or right ventricular end diastolic volume was tested between predefined subgroups. Results In the daily trial, frequent hemodialysis resulted in significant reductions in left ventricular end diastolic volume (−11.0% [95% confidence interval, −16.1% to −5.5%]), left ventricular end systolic volume (−14.8% [−22.7% to −6.2%]), right ventricular end diastolic volume (−11.6% [−19.0% to −3.6%]), and a trend for right ventricular end systolic volume (−11.3% [−21.4% to 0.1%]) compared with conventional therapy. The magnitude of reduction in left and right ventricular end diastolic volumes with frequent hemodialysis was accentuated among patients with residual urine output<100 ml/d (P value [interaction]=0.02). In the nocturnal trial, there were no significant changes in left or right ventricular volumes. The frequent dialysis interventions had no substantial effect on the ratio of left ventricular mass/left ventricular end diastolic volume in either trial. Conclusions Frequent in-center hemodialysis reduces left and right ventricular end systolic and diastolic ventricular volumes as well as left ventricular mass, but it does not affect left ventricular remodeling. PMID:23970131

Drivers of variability in tree transpiration in a Boreal Black Spruce Forest Chronosequence

NASA Astrophysics Data System (ADS)

Angstmann, J. L.; Ewers, B. E.; Kwon, H.

2009-12-01

Boreal forests are of particular interest in climate change studies because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through the impact of more frequent wildfires, warmer, longer growing seasons, and potential drainage of forested wetlands. This study aims to quantify the influence of stand age, drainage condition, and species on tree transpiration and its drivers in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 113 trees (69 Picea mariana (black spruce), 25 Populus tremuloides (trembling aspen), and 19 Pinus banksiana (jack pine) at four stand ages, each containing a well- and poorly-drained site over three growing seasons (2006-2008). Sap flux per unit xylem area, JS, was expressed as transpiration per unit ground area, EC, and transpiration per unit leaf area, EL, using site- and species-specific allometry to obtain sapwood area (AS)and leaf area(AL)per unit ground area. Well-drained, younger Picea mariana daily JS was 47-64% greater than the older well-drained burn ages and younger poorly-drained stands were 64-68% greater than the two oldest poorly-drained stands. Daily EL in the well-drained Picea mariana stands was on average 12-33% higher in younger stand than in the two oldest stands whereas young, poorly-drained Picea mariana had 71% greater daily EL than the older stands. Well-drained Picea mariana trees had 52% higher daily EC than older trees and poorly-drained Picea mariana in the 1964 burn had 42-81% higher daily EC than the oldest stands. Populus tremuloides located in the two youngest stands had daily JS 38-58% greater rates than the 1930 burn, whereas daily EL and EC had no distint differences due to high interannual variability. Pinus banksiana experienced 21-33% greater daily JS in the 1989 burn than in the older 1964 burn for well- and poorly-drained sites. Poorly-drained Pinus banksiana trees from the older 1964 burn had 23-48% greater daily EL and 26-39% higher daily EC than the 1989 burn. Poorly-drained Picea mariana had 17-31% higher daily JS than the well-drained sites. Poorly-drained Picea mariana had 29-58% higher daily EL 42-50% higher daily EC than the well-drained trees. Poorly-drained Pinus banksiana on average had 27-28% higher daily JS than well-drained trees. Poorly-drained Pinus banskiana had 23.25% higher daily EL than well-drained trees and daily EC 32-67% lower than the well-drained trees. Drivers of these differences include midday leaf water potential, AS, and AL.

Ultrasensitive near-infrared photodetectors based on graphene-MoTe2-graphene vertical van der Waals heterostructure

NASA Astrophysics Data System (ADS)

Zhang, Kun; Ye, Yu; Dai, Lun; School of Physics, Peking University Team

Two-dimensional (2D) materials have rapidly established themselves as exceptional building blocks for optoelectronic applications, due to their unique properties and atomically thin nature. Nevertheless, near-infrared (NIR) photodetectors based on layered 2D semiconductors are rarely realized. In this work, we fabricate graphene-MoTe2-graphene vertical vdWs heterostructure by a facile and reliable site controllable transfer method, and apply it for photodetection from visible to the NIR wavelength range. Compared to the 2D semiconductor based photodetectors reported thus far, the graphene-MoTe2-graphene photodetector has superior performance, including high photoresponsivity (110 mA W-1 at 1064 nm and 205 mA W-1 at 473 nm), high external quantum efficiency (EQE, 12.9% at 1064 nm and 53.8% at 473 nm), rapid response and recovery processes (rise time of 24 μs, fall time of 46 μs under 1064 nm illumination), and free from an external source-drain power supply. The all-2D-materials heterostructure has promising applications in future novel high responsivity, high speed and flexible NIR devices.

[Heart arrest].

PubMed

Chiarella, F; Giovannini, E; Bozzano, A; Caristo, G; Delise, P; Fedele, F; Fera, M S; Lavalle, C; Roghi, A; Valagussa, F

2001-03-01

Cardiac arrest is one of the leading causes of mortality in industrialized countries and is mainly due to ischemic heart disease. According to ISTAT estimates, approximately 45,000 sudden deaths occur annually in Italy whereas according to the World Health Organization, its incidence is 1 per 1000 persons. The most common cause of cardiac arrest is ventricular fibrillation due to an acute ischemic episode. During acute ischemia the onset of a ventricular tachyarrhythmia is sudden, unpredictable and often irreversible and lethal. Each minute that passes, the probability that the patient survives decreases by 10%. For this reason, the first 10 min are considered to be priceless for an efficacious first aid. The possibility of survival depends on the presence of witnesses, on the heart rhythm and on the resolution of the arrhythmia. In the majority of cases, the latter is possible by means of electrical defibrillation followed by the reestablishment of systolic function. An increase in equipment alone does not suffice for efficacious handling of cardiac arrest occurring outside the hospital premises. Above all, an adequate intervention strategy is required. Ambulance personnel must be well trained and capable of intervening rapidly, possibly within the first 5 min. The key to success lies in the diffusion and proper use of defibrillators. The availability of new generation instruments, the external automatic defibrillators, encourages their widespread use. On the territory, these emergencies are the responsibility of the 118 organization based, according to the characteristics specific to each country, on the regulated coordination between the operative command, the crews and the first-aid means. Strategies for the handling of these emergencies within hospitals have been proposed by the Conference of Bethesda and tend to guarantee an efficacious resuscitation with a maximum latency of 2 min between cardiac arrest and the first electric shock. The diffusion of external automatic defibrillators is a preventive measure. Such equipment has permitted early defibrillation by non-medical first-aid personnel. These instruments contain software capable of recognizing an arrhythmia which may be defibrillated and of instructing the operator whether and when to press the defibrillation button. The latest instruments deliver the shock by means of a biphasic wave necessitating a lesser amount of energy which can be provided by lighter condensers. Thus such equipment weighs just a couple of kilograms. As suggested by ILCOR, for reasons of priority, such instruments should not only be available within hospitals and in ambulances but also on the territory, in particular in more crowded places. The availability of external automatic defibrillators in such places should reduce the time latency before intervention and thus increase survival. The ILCOR guidelines have suggested the constitution of an itinerary team well equipped for defibrillation and composed of trained personnel of State Institutions such as the Municipal Police, Traffic Police and the Fire Brigades. With regard to the majority of arrhythmias amenable to defibrillation which occur at home or in less crowded places, other strategies, such as primary prevention and training programs for categories at increased risk, must be employed. Antiarrhythmic drugs have long been considered the best solution for the prevention and treatment of ventricular tachyarrhythmias. However, the approach to these pathologies has drastically changed during the last few years owing to accumulating evidence in favor of defibrillators which may be implanted for the primary and secondary prevention of malignant ventricular arrhythmias. For patients with previous cardiac arrest, randomized studies have proven the advantages of such an approach compared to medical therapy. On the basis of the above, the guidelines for the use of antiarrhythmic implants have been modified. In most western countries, the laws regarding this aspect of medicine have recently been renewed. In the United States, where there is the "Law of the Good Samaritan", in order to protect and acquit persons who give first-aid, many states have adopted new laws which promote the use of external automatic defibrillators. Following recent dispositions by the President of the United States that defibrillators should be present in all Federal properties and on civil aircraft, a new Federal Law is about to pass. Italy lacks legislation regarding the use of defibrillators: in order to rectify this position, which is still anchored to existing dispositions of the civil and penal codes including those regarding the omission of first-aid, a bill entitled "The definition and modalities of the use of the external cardiac defibrillator" has recently been presented.

Controlling the ambipolarity and improvement of RF performance using Gaussian Drain Doped TFET

NASA Astrophysics Data System (ADS)

Nigam, Kaushal; Gupta, Sarthak; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

2018-05-01

Ambipolar conduction in tunnel field-effect transistors (TFETs) has been occurred as an inherent issue due to drain-channel tunneling. It makes TFET less efficient and restricts its application in complementary digital circuits. Therefore, this manuscript reports the application of Gaussian doping profile on nanometer regime silicon channel TFETs to completely eliminate the ambipolarity. For this, Gaussian doping is used in the drain region of conventional gate-drain overlap TFET to control the tunneling of electrons from the valence band of channel to the conduction band of drain. As a result, barrier width at the drain/channel junction increases significantly leading to the suppression of an ambipolar current even when higher doping concentration (1 ? 10 ? cm ?) is considered in the drain region. However, significant improvement in terms of RF figure-of-merits such as cut-off frequency (f ?), gain bandwidth product (GBW), and gate-to-drain capacitance (C ?) is achieved with Gaussian doped gate on drain overlap TFET as compared to its counterpart TFET.

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

A left ventricular epicardial to right ventricular endocardial dominant frequency gradient exists in human ventricular fibrillation.

PubMed

Torres, Jose Luis; Shah, Bindi K; Greenberg, Richard M; Deger, Florin Titus; Gerstenfeld, Edward P

2010-10-01

We hypothesized that in patients with left ventricular dysfunction undergoing implant of a biventricular ICD, the local dominant frequency during early induced ventricular fibrillation would be higher at an epicardial left ventricular position compared to an endocardial right ventricular position. Patients undergoing implant of a biventricular ICD were studied. During ventricular fibrillation induction, bipolar electrograms were recorded from leads at an epicardial left ventricular position and an endocardial right ventricular position. Overlapping 2-s fast Fourier transforms were obtained for 6 s of ventricular fibrillation. The dominant frequency and organizational index were compared. Thirty-four patients (20 men, age 64 ± 11 years) underwent 57 inductions of ventricular fibrillation. Eighteen patients had non-ischemic dilated cardiomyopathy and 16 had ischemic dilated cardiomyopathy. The dominant frequency was higher at a lateral epicardial left ventricular position than an apical endocardial right ventricular position in 18 patients with non-ischemic dilated cardiomyopathy (LV epicardial 5.34 ± 0.37 Hz, RV endocardial 5.09 ± 0.41 Hz, p < 0.001), but not in 16 patients with ischemic dilated cardiomyopathy (LV epicardial 4.99 ± 0.57 Hz, RV epicardial 4.87 ± 0.65 Hz, p = 0.094). In patients with non-ischemic dilated cardiomyopathy, there is a dominant frequency gradient during early ventricular fibrillation induced at ICD testing from the lateral left ventricular epicardium to the apical right ventricular endocardium.

Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report

PubMed Central

2010-01-01

Background Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. Case Presentation We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Conclusions Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery. PMID:20492665

Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report.

PubMed

Lai, Peng-Sheng; Lo, Chiao; Lin, Long-Wei; Lee, Po-Chu

2010-05-21

Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery.

Drain site evisceration of fallopian tube, another reason to discourage abdominal drain: report of a case and brief review of literature.

PubMed

Saini, Pradeep; Faridi, M S; Agarwal, Nitin; Gupta, Arun; Kaur, Navneet

2012-04-01

Placement of a drain following abdominal surgery is common despite a lack of convincing evidence in the current literature to support this practice. The use of intra-abdominal drain is associated with many potential and serious complications. We report a drain site evisceration of the right fallopian tube after the removal of an intra-abdominal drain. The drain was placed in the right iliac fossa in a patient who underwent a lower segment Caesarean section (LSCS) for meconium liquor with fetal distress. The Pfannenstiel incision made for LSCS was reopened and the protruding inflamed fimbrial end of the right fallopian tube was excised. The patient made an uneventful recovery. Routine intra-abdominal prophylactic drain following an abdominal surgery including LSCS should be discouraged.

Right ventricular dysfunction affects survival after surgical left ventricular restoration.

PubMed

Couperus, Lotte E; Delgado, Victoria; Palmen, Meindert; van Vessem, Marieke E; Braun, Jerry; Fiocco, Marta; Tops, Laurens F; Verwey, Harriëtte F; Klautz, Robert J M; Schalij, Martin J; Beeres, Saskia L M A

2017-04-01

Several clinical and left ventricular parameters have been associated with prognosis after surgical left ventricular restoration in patients with ischemic heart failure. The aim of this study was to determine the prognostic value of right ventricular function. A total of 139 patients with ischemic heart failure (62 ± 10 years; 79% were male; left ventricular ejection fraction 27% ± 7%) underwent surgical left ventricular restoration. Biventricular function was assessed with echocardiography before surgery. The independent association between all-cause mortality and right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain was assessed. The additive effect of multiple impaired right ventricular parameters on mortality also was assessed. Baseline right ventricular fractional area change was 42% ± 9%, tricuspid annular plane systolic excursion was 18 ± 3 mm, and right ventricular longitudinal peak systolic strain was -24% ± 7%. Within 30 days after surgery, 15 patients died. Right ventricular fractional area change (hazard ratio, 0.93; 95% confidence interval, 0.88-0.98; P < .01), tricuspid annular plane systolic excursion (hazard ratio, 0.80; 95% confidence interval, 0.66-0.96; P = .02), and right ventricular longitudinal peak systolic strain (hazard ratio, 1.15; 95% confidence interval, 1.05-1.26; P < .01) were independently associated with 30-day mortality, after adjusting for left ventricular ejection fraction and aortic crossclamping time. Right ventricular function was impaired in 21%, 20%, and 27% of patients on the basis of right ventricular fractional area change, tricuspid annular plane systolic excursion, and right ventricular longitudinal peak systolic strain, respectively. Any echocardiographic parameter of right ventricular dysfunction was present in 39% of patients. The coexistence of several impaired right ventricular parameters per patient was independently associated with increased 30-day mortality (hazard ratio, 2.83; 95% confidence interval, 1.64-4.87, P < .01 per additional impaired parameter). Baseline right ventricular systolic dysfunction is independently associated with increased mortality in patients with ischemic heart failure undergoing surgical left ventricular restoration. Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Demonstration of uneven distribution of intracranial pulsatility in hydrocephalus patients.

PubMed

Eide, Per K

2008-11-01

Data from intracranial pressure (ICP) recordings in patients with hydrocephalus were reviewed to determine whether intracranial pulsatility within the cerebrospinal fluid (CSF) of cerebral ventricles (ICP(LV)) may differ from that within the brain parenchyma (ICP(PAR)), and whether pulsatility may differ between noncommunicating ventricles. The authors retrieved data from recordings previously obtained in 7 patients with hydrocephalus (noncommunicating in 4 and communicating in 3) and shunt failure who received both an external ventricular drainage (EVD) and an ICP sensor as part of surveillance during intensive care. Simultaneous ICP(LV) and ICP(PAR) signals were available in 6 cases, and simultaneous signals from the lateral and fourth ventricles (ICP(LV) and ICP4V, respectively) were recorded in 1 case. The recordings with both signals were parsed into 6-second time windows. Pulsatility was characterized by the wave amplitude and rise time coefficient, and differences in pulsatility between the ICP(LV) and ICP(PAR) signals (6 cases) or ICP(LV) and ICP4V signals (1 case) were determined. There was uneven distribution of intracranial pulsatility in all 7 patients, shown as significantly elevated pulsatility (that is, higher wave amplitudes and rise time coefficients) within the ventricles (ICP(LV)) than within brain parenchyma (ICP(PAR)) in 6 patients, and significantly higher pulsatility in the fourth (ICP4V) than in the lateral (ICP(LV)) ventricles in 1 patient. Differences > or = 1 mm Hg in ICP wave amplitude were found in 0.5-100% (median 9.4%) of observations in the 7 patients (total number of 6-second time windows, 68,242). The present observations demonstrate uneven distribution of intracranial pulsatility in patients with hydrocephalus, higher pulse pressure amplitudes within the ventricular CSF (ICP(LV)) than within the brain parenchyma (ICP(PAR)). This may be one mechanism behind ventricular enlargement in hydrocephalus.

Effects of milrinone on left ventricular cardiac function during cooling in an intact animal model.

PubMed

Tveita, Torkjel; Sieck, Gary C

2012-08-01

Due to adverse effects of β-receptor agonists reported when applied during hypothermia, left ventricular (LV) cardiac effects of milrinone, a PDE3 inhibitor which mode of action is deprived the sarcolemmal β-receptor-G protein-PKA system, was tested during cooling to 15 °C. Sprague Dawley rats were instrumented to measure left ventricular (LV) pressure-volume changes using a Millar pressure-volume conductance catheter. Core temperature was reduced from 37 to 15 °C (60 min) using internal and external heat exchangers. Milrinone, or saline placebo, was given as continuous i.v. infusions for 30 min at 37 °C and during cooling. In normothermic controls continuous milrinone infusion for 90 min elevated cardiac output (CO) and stroke volume (SV) significantly. Significant differences in cardiac functional variables between the milrinone group and the saline control group during cooling to 15 °C were found: Compared to saline treated animals throughout cooling from 33 to 15 °CSV was significantly elevated in milrinone animals, the index of LV isovolumic relaxation, Tau, was significantly better preserved, and both HR and CO were significantly higher from 33 to 24 °C. Likewise, during cooling between 33 and 28 °C also LVdP/dt(max) was significantly higher in the milrinone group. Milrinone preserved LV systolic and diastolic function at a significantly higher level than in saline controls during cooling to 15 °C. In essential contrast to our previous results when using β-receptor agonists during hypothermia, the present experiment demonstrates the positive inotropic effects of milrinone on LV cardiac function during cooling to 15 °C. Copyright © 2012 Elsevier Inc. All rights reserved.

Complications of intra-cardial placement of silastic central venous catheter in pediatric patients.

PubMed

Soong, W J; Jeng, M J; Hwang, B

1996-01-01

A three-year prospective study was undertaken to determine the incidence and early complications from intra-cardiac placement of percutaneous central venous catheter (CVC). CVC was inserted by using "Catheter-through-needle" technique, and the insertion length was measured by body surface landmark. CVC course and tip location were routinely checked by roentgenography. Echocardiography was performed in case of arrhythmia. After analysis of 784 CVCs, 104 (13.3%) were proved to be intra-cardial, as located by either roentgenography or echocardiography. However, catheters passed via the upper trunk (14.5%) were significantly (p < 0.05) more intra-cardially located than those via the lower trunk (4.8%). Catheters which passed via the right upper trunk veins (basilic, cephalic, or external jugular veins) were also more intra-cardially located than those via their left veins counterparts, but the finding was not statistically significant (p > 0.05). The mean body weight (3.1 +/- 2.4 kg) in the intra-cardial placement group was significantly (p < 0.05) less than that in the non-intracardial placement group (7.9 +/- 4.5 kg). In intra-cardial placement patients, 32 cases (30.8%) had episode(s) of cardiac arrhythmia including 31 premature ventricular depolarization and 1 supra-ventricular tachycardia. All cases showed the presence of intra-ventricular catheter. All arrhythmias ceased abruptly after the catheters were pulled from the hearts. No other early complications were observed. the incidence of the intracardiac placement of CVC is high, especially in small infants or when the insertion via the upper trunk. Short term intra-cardiac catheter placement has a benign clinical course except that the intraventricular catheter may cause arrhythmia. However, this kind of arrhythmia can be resolved spontaneously by withdrawing the catheter.

An elevated source/drain-on-insulator structure to maximize the intrinsic performance of extremely scaled MOSFETs

NASA Astrophysics Data System (ADS)

Zhang, Zhikuan; Zhang, Shengdong; Feng, Chuguang; Chan, Mansun

2003-10-01

In this paper, a source/drain structure separated from the silicon substrate by oxide isolation is fabricated and studied. The source/drain diffusion regions are connected to the shallow source/drain extension through a smaller opening defined by a double spacer process. Experimental results indicate that the source/drain on insulator significantly reduces the parasitic capacitance. Further optimization by simulation indicates a reduction of series resistance and band-to-band drain leakage at off-state can be achieved in extremely scaled devices. Compared with the conventional planner source/drain structure, the reduction of parasitic capacitance and series resistance can be as much as 80% and 30% respectively.

Role of left ventricular twist mechanics in cardiomyopathies, dance of the helices

PubMed Central

Kauer, Floris; Geleijnse, Marcel Leonard; van Dalen, Bastiaan Martijn

2015-01-01

Left ventricular twist is an essential part of left ventricular function. Nevertheless, knowledge is limited in “the cardiology community” as it comes to twist mechanics. Fortunately the development of speckle tracking echocardiography, allowing accurate, reproducible and rapid bedside assessment of left ventricular twist, has boosted the interest in this important mechanical aspect of left ventricular deformation. Although the fundamental physiological role of left ventricular twist is undisputable, the clinical relevance of assessment of left ventricular twist in cardiomyopathies still needs to be established. The fact remains; analysis of left ventricular twist mechanics has already provided substantial pathophysiological understanding on a comprehensive variety of cardiomyopathies. It has become clear that increased left ventricular twist in for example hypertrophic cardiomyopathy may be an early sign of subendocardial (microvascular) dysfunction. Furthermore, decreased left ventricular twist may be caused by left ventricular dilatation or an extensive myocardial scar. Finally, the detection of left ventricular rigid body rotation in noncompaction cardiomyopathy may provide an indispensible method to objectively confirm this difficult diagnosis. All this endorses the value of left ventricular twist in the field of cardiomyopathies and may further encourage the implementation of left ventricular twist parameters in the “diagnostic toolbox” for cardiomyopathies. PMID:26322187

Prospective Validation of Optimal Drain Management "The 3 × 3 Rule" after Liver Resection.

PubMed

Mitsuka, Yusuke; Yamazaki, Shintaro; Yoshida, Nao; Masamichi, Moriguchi; Higaki, Tokio; Takayama, Tadatoshi

2016-09-01

We previously established an optimal postoperative drain management rule after liver resection (i.e., drain removal on postoperative day 3 if the drain fluid bilirubin concentration is <3 mg/dl) from the results of 514 drains of 316 consecutive patients. This test set predicts that 274 of 316 patients (87.0 %) will be safely managed without adverse events when drain management is performed without deviation from the rule. To validate the feasibility of our rule in recent time period. The data from 493 drains of 274 consecutive patients were prospectively collected. Drain fluid volumes, bilirubin levels, and bacteriological cultures were measured on postoperative days (POD) 1, 3, 5, and 7. The drains were removed according to the management rule. The achievement rate of the rule, postoperative adverse events, hospital stay, medical costs, and predictive value for reoperation according to the rule were validated. The rule was achieved in 255 of 274 (93.1 %) patients. The drain removal time was significantly shorter [3 days (1-30) vs. 7 (2-105), p < 0.01], drain fluid infection was less frequent [4 patients (1.5 %) vs. 58 (18.4 %), p < 0.01], postoperative hospital stay was shorter [11 days (6-73) vs. 16 (9-59), p = 0.04], and medical costs were decreased [1453 USD (968-6859) vs. 1847 (4667-9498), p < 0.01] in the validation set compared with the test set. Five patients who required reoperation were predicted by the drain-based information and treated within 2 days after operation. Our 3 × 3 rule is clinically feasible and allows for the early removal of the drain tube with minimum infection risk after liver resection.

Assessment of the use of selected chemical and microbiological constituents as indicators of wastewater in curtain drains from home sewage-treatment systems in Medina County, Ohio

USGS Publications Warehouse

Dumouchelle, Denise H.

2006-01-01

Many home sewage-treatment systems (HSTS) in Ohio use curtain or perimeter drains to depress the level of the subsurface water in and around the systems. These drains could possibly intercept partially untreated wastewater and release potential pathogens to ground-water and surface-water bodies. The quality of water in curtain drains from two different HSTS designs in Medina County, Ohio, was investigated using several methods. Six evaporation-transpiration-absorption (ETA) and five leach-line (LL) systems were investigated by determining nutrient concentrations, chloride/bromide ratios (Cl/Br), Escherichia coli (E. coli ) concentrations, coliphage genotyping, and genetic fingerprinting of E. coli. Water samples were collected at 11 sites and included samples from curtain drains, septic tanks, and residential water wells. Nitrate concentrations in the curtain drains ranged from 0.03 to 3.53 mg/L (milligrams per liter), as N. Concentrations of chloride in 10 of the 11 curtain drains ranged from 5.5 to 21 mg/L; the chloride concentration in the eleventh curtain drain was 340 mg/L. Bromide concentrations in 11 curtain drains ranged from 0.01 to 0.22 mg/L. Cl/Br ratios ranged from 86 to 2,000. F-specific coliphage were not found in any curtain-drain samples. Concentrations of E. coli in the curtain drains ranged from 1 to 760 colonies per 100 milliliters. The curtain-drain water-quality data were evaluated to determine whether HSTS-derived water was present in the curtain drains. Nutrient concentrations were too low to be of use in the determination. The Cl/Br ratios appear promising. Coliphage was not detected in the curtain drains, so genotyping could not be attempted. E. coli concentrations in the curtain drains were all less than those from the corresponding HSTS; only one sample exceeded the Ohio secondary-contact water-quality standard. The genetic fingerprinting data were inconclusive because multiple links between unrelated sites were found. Although the curtain-drain samples from the ETA systems showed somewhat more evidence of the presence of HSTS water than did the LL systems, most of the approaches were inconclusive by themselves. The best evidence of HSTS water, from the Cl/Br ratios, indicates that the water in 10 of the 11 curtain drains, at both HSTS types, was a mixture of dilute ground water and HSTS-derived water; the 11th drain also show some effects of the HSTS, although road salt-affected water may be present. Therefore, it appears that there is no difference between the ETA and LL systems with respect to the water quality in curtain drains.

Safety of transvenous low energy cardioversion of atrial fibrillation in patients with a history of ventricular tachycardia: effects of rate and repolarization time on proarrhythmic risk.

PubMed

Simons, G R; Newby, K H; Kearney, M M; Brandon, M J; Natale, A

1998-02-01

The objective of this study was to assess the safety and efficacy of transvenous low energy cardioversion of atrial fibrillation in patients with ventricular tachycardia and atrial fibrillation and to study the mechanisms of proarrhythmia. Previous studies have demonstrated that cardioversion of atrial fibrillation using low energy, R wave synchronized, direct current shocks applied between catheters in the coronary sinus and right atrium is feasible. However, few data are available regarding the risk of ventricular proarrhythmia posed by internal atrial defibrillation shocks among patients with ventricular arrhythmias or structural heart disease. Atrial defibrillation was performed on 32 patients with monomorphic ventricular tachycardia and left ventricular dysfunction. Shocks were administered during atrial fibrillation (baseline shocks), isoproterenol infusion, ventricular pacing, ventricular tachycardia, and atrial pacing. Baseline shocks were also administered to 29 patients with a history of atrial fibrillation but no ventricular arrhythmias. A total of 932 baseline shocks were administered. No ventricular proarrhythmia was observed after well-synchronized baseline shocks, although rare inductions of ventricular fibrillation occurred after inappropriate T wave sensing. Shocks administered during wide-complex rhythms (ventricular pacing or ventricular tachycardia) frequently induced ventricular arrhythmias, but shocks administered during atrial pacing at identical ventricular rates did not cause proarrhythmia. The risk of ventricular proarrhythmia after well-synchronized atrial defibrillation shocks administered during narrow-complex rhythms is low, even in patients with a history of ventricular tachycardia. The mechanism of proarrhythmia during wide-complex rhythms appears not to be related to ventricular rate per se, but rather to the temporal relationship between shock delivery and the repolarization time of the previous QRS complex.

Value of right ventricular mapping in patients with postinfarction ventricular tachycardia.

PubMed

Yokokawa, Miki; Good, Eric; Crawford, Thomas; Chugh, Aman; Pelosi, Frank; Latchamsetty, Rakesh; Oral, Hakan; Morady, Fred; Bogun, Frank

2012-06-01

Postinfarction ventricular tachycardia (VT) typically involves the left ventricular endocardium. Right ventricular involvement in the arrhythmogenic substrate of postinfarction VT is considered unusual. To assess the role of right ventricular mapping and ablation in patients with prior septal myocardial infarction. From among 37 consecutive patients with recurrent postinfarction VT, 18 patients with evidence of left ventricular septal involvement of myocardial infarction were identified; these patients were the subjects of this report. In these 18 patients, 166 VTs (cycle length 372 ± 117 ms) were induced. Right ventricular voltage mapping was performed in all 18 patients with left ventricular septal myocardial infarction. Right ventricular voltage mapping showed areas of low voltage in 11 patients; pace mapping from these areas revealed matching pace maps for 17 VTs, and radiofrequency ablation from the right ventricular endocardium but not the left ventricular endocardium eliminated 14 of 17 VTs. VTs with critical components in the right ventricle had a left bundle branch block morphology that had similar characteristics as left bundle branch block VTs with critical areas involving the left ventricular septum. Patients with right ventricular VT breakthrough sites had a lower ejection fraction than did patients without VT breaking out on the right ventricular septum (18% ± 5% vs 33% ± 15%; P = .01). Right ventricular mapping and ablation may be necessary in order to eliminate all inducible VTs in patients with postinfarction VT. More than half the patients with septal myocardial infarction have right ventricular septal areas that are critical for postinfarction VT and that cannot be eliminated by left ventricular ablation alone. Copyright © 2012 Heart Rhythm Society. All rights reserved.

Safety drain system for fluid reservoir

NASA Technical Reports Server (NTRS)

England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

2012-01-01

A safety drain system includes a plurality of drain sections, each of which defines distinct fluid flow paths. At least a portion of the fluid flow paths commence at a side of the drain section that is in fluid communication with a reservoir's fluid. Each fluid flow path at the side communicating with the reservoir's fluid defines an opening having a smallest dimension not to exceed approximately one centimeter. The drain sections are distributed over at least one surface of the reservoir. A manifold is coupled to the drain sections.

Dynamic Changes of QRS Morphology of Premature Ventricular Contractions During Ablation in the Right Ventricular Outflow Tract: A Case Report.

PubMed

Yue-Chun, Li; Jia-Feng, Lin; Jia-Xuan, Lin

2015-10-01

Electrocardiographic characteristics can be useful in differentiating between right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) ventricular arrhythmias. Ventricular arrhythmias originating from ASC, however, show preferential conduction to RVOT that may render the algorithms of electrocardiographic characteristics less reliable. Even though there are few reports describing ventricular arrhythmias with ASC origins and endocardial breakout sites of RVOT, progressive dynamic changes in QRS morphology of the ventricular arrhythmias during ablation obtained were rare.This case report describes a patient with symptomatic premature ventricular contractions of left ASC origin presenting an electrocardiogram (ECG) characteristic of right ventricular outflow tract before ablation. Pacing at right ventricular outflow tract reproduced an excellent pace map. When radiofrequency catheter ablation was applied to the right ventricular outflow tract, the QRS morphology of premature ventricular contractions progressively changed from ECG characteristics of right ventricular outflow tract origin to ECG characteristics of left ASC origin.Successful radiofrequency catheter ablation was achieved at the site of the earliest ventricular activation in the left ASC. The distance between the successful ablation site of the left ASC and the site with an excellent pace map of the RVOT was 20 mm.The ndings could be strong evidence for a preferential conduction via the myocardial bers from the ASC origin to the breakout site in the right ventricular outflow tract. This case demonstrates that ventricular arrhythmias with a single origin and exit shift may exhibit QRS morphology changes.

Containment vessel drain system

DOEpatents

Harris, Scott G.

2018-01-30

A system for draining a containment vessel may include a drain inlet located in a lower portion of the containment vessel. The containment vessel may be at least partially filled with a liquid, and the drain inlet may be located below a surface of the liquid. The system may further comprise an inlet located in an upper portion of the containment vessel. The inlet may be configured to insert pressurized gas into the containment vessel to form a pressurized region above the surface of the liquid, and the pressurized region may operate to apply a surface pressure that forces the liquid into the drain inlet. Additionally, a fluid separation device may be operatively connected to the drain inlet. The fluid separation device may be configured to separate the liquid from the pressurized gas that enters the drain inlet after the surface of the liquid falls below the drain inlet.

[Experiences with the extracardial conduit in the reconstruction of the right ventricular outflow tract].

PubMed

Egloff, L; Schönbeck, M; Arbenz, U; Turina, M; Senning, A

1982-12-18

Operative correction of certain congenital cardiac malformations with discontinuity between the right ventricle and pulmonary artery is technically possible today with satisfactory late results. The atretic or hypoplastic outflow tract can be bridged by an external tubular graft containing a valvular prosthesis. Of 22 patients operated upon from 1978-1981, 16 survived the operation and perioperative period. There was one late death. Routine cardiac catheterization was performed in 6 non-selected patients between 7 and 22 months after surgery. No hemodynamically important gradients were found. The extracardiac conduit between the right ventricle and pulmonary artery has become an important tool in correcting certain forms of congenital heart disease.

Relaxation of Isolated Ventricular Cardiomyocytes by a Voltage-Dependent Process

NASA Astrophysics Data System (ADS)

Bridge, John H. B.; Spitzer, Kenneth W.; Ershler, Philip R.

1988-08-01

Cell contraction and relaxation were measured in single voltage-clamped guinea pig cardiomyocytes to investigate the contribution of sarcolemmal Na+-Ca2+ exchange to mechanical relaxation. Cells clamped from -80 to 0 millivolts displayed initial phasic and subsequent tonic contractions; caffeine reduced or abolished the phasic and enlarged the tonic contraction. The rate of relaxation from tonic contractions was steeply voltage-dependent and was significantly slowed in the absence of a sarcolemmal Na+ gradient. Tonic contractions elicited in the absence of a Na+ gradient promptly relaxed when external Na+ was applied, reflecting activation of Na+-Ca2+ exchange. It appears that a voltage-dependent Na+-Ca2+ exchange can rapidly mechanically relax mammalian heart muscle.

Evaluation of wick drain performance in Virginia soils.

DOT National Transportation Integrated Search

2003-01-01

Prefabricated vertical drains (PVD), also known as wick drains, are commonly used to accelerate the consolidation of fine-grained soils in order to reduce future settlements and increase shear strength. Various drain designs are currently on the mark...

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

PubMed

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

2017-04-01

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. 144 consecutive patients who underwent abscess drainage at a single institution were reviewed retrospectively. Larger initial drain size did not reduce drainage time, drain occlusion, or drain exchanges (P > .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. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

KSC-2010-5940

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Technicians in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida will begin to remove thermal sensors that will give engineers data about the changes space shuttle Discovery's external fuel tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5938

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

Terahertz signal detection in a short gate length field-effect transistor with a two-dimensional electron gas

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

Vostokov, N. V., E-mail: vostokov@ipm.sci-nnov.ru; Shashkin, V. I.

2015-11-28

We consider the problem of non-resonant detection of terahertz signals in a short gate length field-effect transistor having a two-dimensional electron channel with zero external bias between the source and the drain. The channel resistance, gate-channel capacitance, and quadratic nonlinearity parameter of the transistor during detection as a function of the gate bias voltage are studied. Characteristics of detection of the transistor connected in an antenna with real impedance are analyzed. The consideration is based on both a simple one-dimensional model of the transistor and allowance for the two-dimensional distribution of the electric field in the transistor structure. The resultsmore » given by the different models are discussed.« less

Pb/InAs nanowire josephson junction with high critical current and magnetic flux focusing.

PubMed

Paajaste, J; Amado, M; Roddaro, S; Bergeret, F S; Ercolani, D; Sorba, L; Giazotto, F

2015-03-11

We have studied mesoscopic Josephson junctions formed by highly n-doped InAs nanowires and superconducting Ti/Pb source and drain leads. The current-voltage properties of the system are investigated by varying temperature and external out-of-plane magnetic field. Superconductivity in the Pb electrodes persists up to ∼7 K and with magnetic field values up to 0.4 T. Josephson coupling at zero backgate voltage is observed up to 4.5 K and the critical current is measured to be as high as 615 nA. The supercurrent suppression as a function of the magnetic field reveals a diffraction pattern that is explained by a strong magnetic flux focusing provided by the superconducting electrodes forming the junction.

Preferential flow estimates to an agricultural tile drain with implications for glyphosate transport

USGS Publications Warehouse

Stone, W.W.; Wilson, J.T.

2006-01-01

Agricultural subsurface drains, commonly referred to as tile drains, are potentially significant pathways for the movement of fertilizers and pesticides to streams and ditches in much of the Midwest. Preferential flow in the unsaturated zone provides a route for water and solutes to bypass the soil matrix and reach tile drains faster than predicted by traditional displacement theory. This paper uses chloride concentrations to estimate preferential flow contributions to a tile drain during two storms in May 2004. Chloride, a conservative anion, was selected as the tracer because of differences in chloride concentrations between the two sources of water to the tile drain, preferential and matrix flow. A strong correlation between specific conductance and chloride concentration provided a mechanism to estimate chloride concentrations in the tile drain throughout the storm hydrographs. A simple mixing analysis was used to identify the preferential flow component of the storm hydrograph. During two storms, preferential flow contributed 11 and 51% of total storm tile drain flow; the peak contributions, 40 and 81%, coincided with the peak tile drain flow. Positive relations between glyphosate [N-(phosphonomethyl)glycine] concentrations and preferential flow for the two storms suggest that preferential flow is an important transport pathway to the tile drain. ?? ASA, CSSA, SSSA.

Secondary ventricular fibrillation or pulseless ventricular tachycardia during cardiac arrest and epinephrine dosing.

PubMed

Straznitskas, Andrew D; Wong, Sylvia; Kupchik, Nicole; Carlbom, David

2015-05-01

Development of ventricular fibrillation or pulseless ventricular tachycardia after an initial rhythm of pulseless electrical activity or asystole is associated with significantly increased cardiac arrest mortality. To examine differences in epinephrine administration during cardiac arrest between patients who had a secondary ventricular fibrillation or ventricular tachycardia develop and patients who did not. Data were collected for 2 groups of patients with in-hospital cardiac arrest and an initial rhythm of pulseless electrical activity or asystole: those who had a secondary ventricular fibrillation or ventricular tachycardia develop (cases) and those who did not (controls). Dosing of epinephrine during cardiac arrest and other variables were compared between cases and controls. Of the 215 patients identified with an initial rhythm of pulseless electrical activity or asystole, 51 (23.7%) had a secondary ventricular fibrillation or ventricular tachycardia develop. Throughout the total duration of arrest, including periods of return of spontaneous circulation, the dosing interval for epinephrine in patients who had a secondary ventricular fibrillation or ventricular tachycardia develop was 1 mg every 3.4 minutes compared with 1 mg every 5 minutes in controls (P= .001). For the total duration of pulselessness, excluding periods of return of spontaneous circulation during the arrest, the dosing interval for epinephrine in patients who had a secondary ventricular fibrillation or ventricular tachycardia develop was 1 mg every 3.1 minutes versus 1 mg every 4.3 minutes in controls (P= .001). More frequent administration of epinephrine during cardiac arrest is associated with development of secondary ventricular fibrillation or ventricular tachycardia. ©2015 American Association of Critical-Care Nurses.

Phytoplankton abundance and structure as indicator of water quality in the drainage system of the Burullus Lagoon, southern Mediterranean coast, Egypt.

PubMed

El-Kassas, Hala Yassin; Gharib, Samiha Mahmoud

2016-09-01

This study represents the first detailed account of phytoplankton community structure and seasonal succession in eight drain sites and the Brimbal Canal influx into the Burullus Lagoon. The phytoplankton characteristics were studied based on the data collected seasonally over 4 years, from summer 2012 to spring 2016. Various indices such as Palmer's and Shannon's biotic indices were used for the assessment of the water quality of the different drains. There were a total of 194 species belonging to 65 genera and 6 groups: Bacillariophyceae (76 species), Chlorophyceae (59 species), Cyanophyceae (30 species), Euglenophyceae (25 species), Dinophyceae (3 species), and Xanthophyceae (1 species). The phytoplankton community was dominated with diatoms, green algae, and euglenoids such as Cyclotella, Scenedesmus, Navicula, Nitzschia, Ankistrodesmus, Chlorella, and Euglena. Maximum and minimum phytoplankton abundance was recorded at the Brimbal Canal and Hooks Drain. Maximum and minimum species diversities (H') were found at the Hooks Drain (2.564) and Burullus Drain (2.055). Species evenness fluctuated between 0.595 (Burullus Drain) and 0.750 (West Burullus Drain). The total score of algal genus pollution index and the algal species pollution index at the different drains showed that Drain 7 and the West Burullus Drain had moderate pollution, and the total score of the other drains were greater than 20 indicating the confirmed high organic pollution. Thus, the present investigation can be considered an attempt to use the phytoplankton community as a bioindicator of organic pollution.

Fibrosis-Related Gene Expression in Single Ventricle Heart Disease.

PubMed

Nakano, Stephanie J; Siomos, Austine K; Garcia, Anastacia M; Nguyen, Hieu; SooHoo, Megan; Galambos, Csaba; Nunley, Karin; Stauffer, Brian L; Sucharov, Carmen C; Miyamoto, Shelley D

2017-12-01

To evaluate fibrosis and fibrosis-related gene expression in the myocardium of pediatric subjects with single ventricle with right ventricular failure. Real-time quantitative polymerase chain reaction was performed on explanted right ventricular myocardium of pediatric subjects with single ventricle disease and controls with nonfailing heart disease. Subjects were divided into 3 groups: single ventricle failing (right ventricular failure before or after stage I palliation), single ventricle nonfailing (infants listed for primary transplantation with normal right ventricular function), and stage III (Fontan or right ventricular failure after stage III). To evaluate subjects of similar age and right ventricular volume loading, single ventricle disease with failure was compared with single ventricle without failure and stage III was compared with nonfailing right ventricular disease. Histologic fibrosis was assessed in all hearts. Mann-Whitney tests were performed to identify differences in gene expression. Collagen (Col1α, Col3) expression is decreased in single ventricle congenital heart disease with failure compared with nonfailing single ventricle congenital heart disease (P = .019 and P = .035, respectively), and is equivalent in stage III compared with nonfailing right ventricular heart disease. Tissue inhibitors of metalloproteinase (TIMP-1, TIMP-3, and TIMP-4) are downregulated in stage III compared with nonfailing right ventricular heart disease (P = .0047, P = .013 and P = .013, respectively). Matrix metalloproteinases (MMP-2, MMP-9) are similar between nonfailing single ventricular heart disease and failing single ventricular heart disease, and between stage III heart disease and nonfailing right ventricular heart disease. There is no difference in the prevalence of right ventricular fibrosis by histology in subjects with single ventricular failure heart disease with right ventricular failure (18%) compared with those with normal right ventricular function (38%). Fibrosis is not a primary contributor to right ventricular failure in infants and young children with single ventricular heart disease. Additional studies are required to understand whether antifibrotic therapies are beneficial in this population. Copyright © 2017 Elsevier Inc. All rights reserved.

Discharge characteristics of four highway drainage systems in Ohio

USGS Publications Warehouse

Straub, D.E.

1995-01-01

Excessive water in the subbase of high-way combined with large traffic volumes and heavy loads is a major cause of road deterioration. Prompt removal of any excess water in a subbase will decrease the road deterioration and extend the effective life of a highway. This study presents discharge characteristics of four highway subbase drainage systems. These systems consisted of shallow, longitudal trenches with geocomposite drain materials (edge drains made from a polyethylene core surrounded by a geotextile filter fabric) that underline the joint between the shoulder and the traffic lane of State Route 16, approximately 1.0 mile southeast of Granville, Ohio. For selected rainfall-runoff events the maximum discharge, discharge characteristics from April 1991 through November 1993 were computed for three geocomposite products- a post type, an oblong-pipe type, and a cusp type-and a conventional perforated pipe edge drain. In general, the discharge characteristics of the conventional edge drain and that of the oblong-pipe edge drain were similar for most of the rainfall-runoff event characteristics. Both produced most of the highest maximum discharges and largest discharge volumes among the four longitudal edge drains. The post edge drain produced smaller maximum discharge and volumes than the conventional and oblong-pipe edge drains, but it had the shortest lag times for most of the event characteristics. The cusp edge drain produced small maximum discharges and small volumes similar to those from the post edge drain, but it had the longest lag times of all the edge drains for most of the event characteristics. The cusp edge drain may have also had some problems during installation which could have affected the discharge characteristics.

Fallopian Tube Herniation through Left Sided Abdominal Drain Site.

PubMed

Hussain, Khalid; Masood, Jovaria

2016-06-01

Intra-abdominal drains have been used since long to prevent intra-abdominal collection, and detect any anastomotic leaks. We report a case of left sided fallopian tube herniation from a left lower abdominal drain site in a 27-year female who underwent caesarian section for breach presentation. Several complications related to drain usage has been described but left sided fallopian tube prolapse through drain site has not been reported in literature.

Investigation of membranous ventricular septal defect complicated with tricuspid regurgitation in ventricular septal defect occlusion

PubMed Central

LIU, SHU-PING; LI, LI; YAO, KE-CHUN; WANG, NA; WANG, JIAN-CHANG

2013-01-01

This study aimed to explore the mechanism of membranous ventricular septal defect complicated with tricuspid regurgitation and the significance of ventricular septal defect occlusion by echocardiography. A total of 43 patients with membranous ventricular septal defect complicated with tricuspid regurgitation were observed by echocardiography and the changes in length, area and volume of tricuspid regurgitation prior to and following ventricular septal defect occlusion were measured. There were four different mechanisms of membranous ventricular septal defect complicated with tricuspid regurgitation. The various indices of tricuspid regurgitation volume were significantly reduced following occlusion. Ventricular septal defect occlusion significantly reduces tricuspid regurgitation volume complicated with membranous ventricular septal defect and echocardiography is an ideal method to detect these changes. PMID:23404058

The value of right ventricular longitudinal strain in the evaluation of adult patients with repaired tetralogy of Fallot: a new tool for a contemporary challenge.

PubMed

Almeida-Morais, Luís; Pereira-da-Silva, Tiago; Branco, Luísa; Timóteo, Ana T; Agapito, Ana; de Sousa, Lídia; Oliveira, José A; Thomas, Boban; Jalles-Tavares, Nuno; Soares, Rui; Galrinho, Ana; Cruz-Ferreira, Rui

2017-04-01

The role of right ventricular longitudinal strain for assessing patients with repaired tetralogy of Fallot is not fully understood. In this study, we aimed to evaluate its relation with other structural and functional parameters in these patients. Patients followed-up in a grown-up CHD unit, assessed by transthoracic echocardiography, cardiac MRI, and treadmill exercise testing, were retrospectively evaluated. Right ventricular size and function and pulmonary regurgitation severity were assessed by echocardiography and MRI. Right ventricular longitudinal strain was evaluated in the four-chamber view using the standard semiautomatic method. In total, 42 patients were included (61% male, 32±8 years). The mean right ventricular longitudinal strain was -16.2±3.7%, and the right ventricular ejection fraction, measured by MRI, was 42.9±7.2%. Longitudinal strain showed linear correlation with tricuspid annular systolic excursion (r=-0.40) and right ventricular ejection fraction (r=-0.45) (all p<0.05), which in turn showed linear correlation with right ventricular fractional area change (r=0.50), pulmonary regurgitation colour length (r=0.35), right ventricular end-systolic volume (r=-0.60), and left ventricular ejection fraction (r=0.36) (all p<0.05). Longitudinal strain (β=-0.72, 95% confidence interval -1.41, -0.15) and left ventricular ejection fraction (β=0.39, 95% confidence interval 0.11, 0.67) were independently associated with right ventricular ejection fraction. The best threshold of longitudinal strain for predicting a right ventricular ejection fraction of <40% was -17.0%. Right ventricular longitudinal strain is a powerful method for evaluating patients with tetralogy of Fallot. It correlated with echocardiographic right ventricular function parameters and was independently associated with right ventricular ejection fraction derived by MRI.

Growth of left ventricular outflow tract and predictors of future re-intervention after repair for ventricular septal defect and aortic arch obstruction.

PubMed

Jijeh, Abdulraouf; Ismail, Muna; Alhabshan, Fahad

2017-09-01

Ventricular septal defect and aortic arch obstruction are usually associated with a narrow left ventricular outflow tract. The aim of the present study was to analyse the growth and predictors of future obstruction of the left ventricular outflow tract after surgical repair. We carried out a retrospective review of patients who underwent repair for ventricular septal defect and aortic arch obstruction - coarctation or interrupted aortic arch - between July, 2002 and June, 2013. Echocardiographic data were reviewed, and the need for re-intervention was evaluated. A total of 89 patients were included in this study. A significant left ventricular outflow tract growth was noticed after surgical repair. Preoperatively, the mean left ventricular outflow tract Z-score was -1.46±1 (range -5.5 to 1.1) and increased to a mean value of -0.7±1.3 (range -2.7 to 3.2) at last follow-up (p=0.0001), demonstrating relevant growth of the left ventricular outflow tract after repair for ventricular septal defect and aortic arch obstruction. After primary repair, 11 patients (12.3%) required re-intervention with surgical repair for left ventricular outflow tract obstruction after a mean period of 36±21 months. There were no significant differences in age, weight, and indexed aortic valve and left ventricular outflow tract measurements between those who developed obstruction and those who did not. Significant left ventricular outflow tract growth is expected after repair of ventricular septal defect and aortic arch obstruction. Small aortic valve and left ventricular outflow tract at diagnosis are not risk factors to predict the need for surgical re-intervention for left ventricular outflow tract obstruction in future.

Drain Management after Pancreatoduodenectomy: Reappraisal of a Prospective Randomized Trial Using Risk Stratification.

PubMed

McMillan, Matthew T; Malleo, Giuseppe; Bassi, Claudio; Butturini, Giovanni; Salvia, Roberto; Roses, Robert E; Lee, Major K; Fraker, Douglas L; Drebin, Jeffrey A; Vollmer, Charles M

2015-10-01

A recent randomized trial used the Fistula Risk Score (FRS) to develop guidelines for selective drainage based on clinically relevant fistula (CR-POPF) risk. Additionally, postoperative day (POD) 1 drain and serum amylase have been identified as accurate postoperative predictors of CR-POPF. This study sought to identify patients who may benefit from selective drainage, as well as the optimal timing for drain removal after pancreatoduodenectomy. One hundred six pancreatoduodenectomies from a previously reported RCT were assessed using risk-adjustment. The incidence of CR-POPF was compared between FRS risk cohorts. Drain and serum amylase values from POD 1 were evaluated using receiver operating characteristic (ROC) analysis to establish cut-offs predictive of CR-POPF occurrence. A regression analysis compared drain removal randomizations (POD 3 vs POD 5). Three-quarters of patients had moderate/high CR-POPF risk. This group had a CR-POPF rate of 36.3% vs 7.7% among negligible/low risk patients (p = 0.005). The areas under the ROC curve for CR-POPF prediction using POD 1 drain and serum amylase values were 0.800 (p = 0.000001; 95% CI 0.70-0.90) and 0.655 (p = 0.012; 95% CI 0.55-0.77), respectively. No significant serum amylase cut-offs were identified. Moderate/high risk patients with POD 1 drain amylase ≤ 5,000 U/L had significantly lower rates of CR-POPF when randomized to POD 3 drain removal (4.2% vs 38.5%; p = 0.003); moreover, these patients experienced fewer complications and shorter hospital stays. A clinical care protocol is proposed whereby drains are recommended for moderate/high FRS risk patients, but may be omitted in patients with negligible/low risk. Drain amylase values in moderate/high risk patients should then be evaluated on POD 1 to determine the optimal timing for drain removal. Moderate/high risk patients with POD 1 drain amylase ≤ 5,000 U/L have lower rates of CR-POPF with POD 3 (vs POD ≥ 5) drain removal; early drain removal is recommended for these patients. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Magnetic suspension of the rotor of a ventricular assist device of mixed flow type.

PubMed

Horikawa, Oswaldo; de Andrade, Aron José Pazin; da Silva, Isaías; Bock, Eduardo Guy Perpetuo

2008-04-01

This work presents results of preliminary studies concerning application of magnetic bearing in a ventricular assist device (VAD) being developed by Dante Pazzanese Institute of Cardiology-IDPC (São Paulo, Brazil). The VAD-IDPC has a novel architecture that distinguishes from other known VADs. In this, the rotor has a conical geometry with spiral impellers, showing characteristics that are intermediate between a centrifugal VAD and an axial VAD. The effectiveness of this new type of blood pumping principle was showed by tests and by using it in heart surgery for external blood circulation. However, the developed VAD uses a combination of ball bearings and mechanical seals, limiting the life for some 10 h, making impossible its long-term use or its use as an implantable VAD. As a part of development of an implantable VAD, this work aims at the replacement of ball bearings by a magnetic bearing. The most important magnetic bearing principles are studied and the magnetic bearing developed by Escola Politécnica of São Paulo University (EPUSP-MB) is elected because of its very simple architecture. Besides presenting the principle of the EPUSP-MB, this work presents one possible alternative for applying the EPUSP-MB in the IDPC-VAD.

Detection of ventricular fibrillation in the presence of cardiopulmonary resuscitation artefacts.

PubMed

Aramendi, Elisabete; de Gauna, Sofia Ruiz; Irusta, Unai; Ruiz, Jesus; Arcocha, M Fe; Ormaetxe, Jose Miguel

2007-01-01

Providing cardiopulmonary resuscitation (CPR) to a patient in cardiac arrest introduces artefacts into the electrocardiogram (ECG), corrupting the diagnosis of the underlying heart rhythm. CPR must therefore be discontinued for reliable shock advice analysis by an automated external defibrillator (AED). Detection of ventricular fibrillation (VF) during CPR would enable CPR to continue during AED rhythm analysis, thereby increasing the likelihood of resuscitation success. This study presents a new adaptive filtering method to clean the ECG. The approach consists of a filter that adapts its characteristics to the spectral content of the signal exclusively using the surface ECG that commercial AEDs capture through standard patches. A set of 200 VF and 25 CPR artefact samples collected from real out-of-hospital interventions were used to test the method. The performance of a shock advice algorithm was evaluated before and after artefact removal. CPR artefacts were added to the ECG signals and four degrees of corruption were tested. Mean sensitivities of 97.83%, 98.27%, 98.32% and 98.02% were achieved, producing sensitivity increases of 28.44%, 49.75%, 59.10% and 64.25%, respectively, sufficient for ECG analysis during CPR. Although satisfactory and encouraging sensitivity values have been obtained, further clinical and experimental investigation is required in order to integrate this type of artefact suppressing algorithm in current AEDs.

Specific considerations with the automatic implantable atrial defibrillator.

PubMed

Jung, W; Wolpert, C; Esmailzadeh, B; Spehl, S; Herwig, S; Schumacher, B; Lewalter, T; Omran, H; Kirchhoff, P G; Lüderitz, B

1998-08-01

Internal atrial defibrillation has been evaluated as an alternative approach to the external technique for more than two decades. Previous studies in animals and humans have shown that internal atrial defibrillation is feasible with relatively low energies. The promising results achieved with internal atrial defibrillation have facilitated the development of an implantable atrial defibrillator (IAD). For any new therapy, it is imperative to demonstrate safety, efficacy, tolerability with improvement in quality of life, and cost-effectiveness compared with therapeutic options already available. Maintenance of sinus rhythm or prolonged duration in arrhythmia-free intervals should be demonstrated clearly with an IAD. Initial clinical experience with the Metrix system indicates stable atrial defibrillation thresholds, appropriate R wave synchronization markers, no shock-induced ventricular proarrhythmia, and excellent detection of atrial fibrillation (AF) with a specificity of 100%. Ventricular proarrhythmia has not been reported for correctly R wave synchronized low-energy shocks when closely coupled to RR intervals, and long-short cycles are avoided. Preliminary experience with the Metrix system suggests that the IAD may offer a therapeutic alternative for a subgroup of patients with drug-refractory, symptomatic, long-lasting, and infrequent episodes of AF. Further efforts must be undertaken to reduce the patient discomfort associated with internal atrial defibrillation in an attempt to make this new therapy acceptable to a larger patient population with AF.

Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device.

PubMed

Fujimura, R; Lober, R; Kamian, K; Kleiner, L

2018-01-01

Programmable ventricular shunt valves are commonly used to treat hydrocephalus. They can be adjusted to allow for varying amounts of cerebrospinal fluid (CSF) flow using an external magnetic programming device, and are susceptible to maladjustment from inadvertent exposure to magnetic fields. We describe the case of a 3-month-old girl treated for hydrocephalus with a programmable Strata TM II valve found at the incorrect setting on multiple occasions during her hospitalization despite frequent reprogramming and surveillance. We found that the Vocera badge, a common hands-free wireless communication system worn by our nursing staff, had a strong enough magnetic field to unintentionally change the shunt setting. The device is worn on the chest bringing it into close proximity to the shunt valve when care providers hold the baby, resulting in the maladjustment. Some commonly used medical devices have a magnetic field strong enough to alter programmable shunt valve settings. Here, we report that the magnetic field from the Vocera hands-free wireless communication system, combined with the worn position, results in shunt maladjustment for the Strata TM II valve. Healthcare facilities using the Vocera badges need to put protocols in place and properly educate staff members to ensure the safety of patients with Strata TM II valves.

Factors confounding impedance catheter volume measurements in vitro.

PubMed

Bielefeld, M R; Cabreriza, S E; Spotnitz, H M

1993-06-01

The impedance catheter allows continuous measurement of ventricular volume. External influences have been described as causing parallel shifts in impedance-measured volumes; however, factors affecting impedance measurements in a nonparallel manner have not been fully characterized. Accordingly, an impedance catheter was placed inside a latex balloon into which known volumes of normal saline solution were injected. Conductive and nonconductive materials were individually placed within the balloon. Impedance was measured with materials touching (T) or not touching (NT) the catheter. Impedance-measured volumes were plotted versus actual volumes. Compared with the line of identity (LID), a statistical difference (p < 0.05) was found in the slopes in the presence of metallic objects only. These included a pacing lead (T, NT) (mT = 1.32m mNT = 1.29 versus mLID = 1.00), titanium (T) (mT = 1.68 versus mLID = 1.00), and aluminum (NT) (mNT = 0.72 versus mLID = 1.00). These changes in slope indicate nonparallel effects on impedance that confound the ability of the impedance catheter to determine volumes in vitro. These observations imply that serial calibration of both the slope constant (alpha) and the intercept (parallel conductance) of impedance may be necessary for in vivo measurements of ventricular volume based on impedance in the presence of metallic objects.

Large right ventricular sinusoids in an infant with aorta-left ventricular tunnel and proximal right coronary artery atresia.

PubMed

Chen, Peter C; Spinner, Joseph A; Heinle, Jeffrey S

2018-07-01

We report a 1-month-old infant diagnosed with an aorta-left ventricular tunnel, ventricular septal defect, and right coronary atresia with right ventricular sinusoids. The patient's anatomy and physiology did not indicate right-ventricular-dependent coronary circulation, and therefore right ventricular decompression could be performed without compromising coronary perfusion during surgical correction. A detailed understanding of the coronary anatomy is critical in managing this defect when coronary anomalies are present.

Does stereo-endoscopy improve neurosurgical targeting in 3rd ventriculostomy?

NASA Astrophysics Data System (ADS)

Abhari, Kamyar; de Ribaupierre, Sandrine; Peters, Terry; Eagleson, Roy

2011-03-01

Endoscopic third ventriculostomy is a minimally invasive surgical technique to treat hydrocephalus; a condition where patients suffer from excessive amounts of cerebrospinal fluid (CSF) in the ventricular system of their brain. This technique involves using a monocular endoscope to locate the third ventricle, where a hole can be made to drain excessive fluid. Since a monocular endoscope provides only a 2D view, it is difficult to make this perforation due to the lack of monocular cues and depth perception. In a previous study, we had investigated the use of a stereo-endoscope to allow neurosurgeons to locate and avoid hazardous areas on the surface of the third ventricle. In this paper, we extend our previous study by developing a new methodology to evaluate the targeting performance in piercing the hole in the membrane. We consider the accuracy of this surgical task and derive an index of performance for a task which does not have a well-defined position or width of target. Our performance metric is sensitive and can distinguish between experts and novices. We make use of this metric to demonstrate an objective learning curve on this task for each subject.

[Assessment of external breathing parameters and cardiovascular function in patients with constitutive exogenous obesity and reduced body weight].

PubMed

Merzlikina, N L; Romantsova, T I; Roik, O V; Lobanova, N A; Drapkina, O M; Ivashkin, V T

2009-01-01

The study was designed to evaluate external respiratory function (ERF) and cardiovascular function based on AP measurements, results of 24 hour AP monitoring, treadmill test, and ECG during weight loss therapy in patients with excess body mass. A total of 93 patients with grade 2-3 obesity were examined including 41 (39.8%) with type 2 diabetes mellitus (DM). Group 1 consisted of patients with constitutive exogenous obesity, group 2 of patients with constitutive exogenous obesity and DM, group 3 was used as control. Follow-up studies were conducted after 6 and 12 months. Patients of groups 1 and 2 showed positive dynamics of hemodynamic characteristics related to the loss of weight including significant reduction of heart rate, systolic and diastolic indices of hypertonic loading, specific peripheral vascular resistance, and left ventricular mass. Simultaneously, cardiac index and ERF increased while vital lung capacity, forced vital capacity, and forced respiratory volume in the first second returned to normal values. It is concluded that reduction of body weight has positive effect on ERF dynamics and hemodynamic characteristics in patients with constitutive exogenous obesity.

The construction of tridimensional representation of body and external reality in man. The greatest achievement of evolution to date implications for virtual reality.

PubMed

Woodbury, M A; Woodbury, M F

1998-01-01

Our 3-D Body Representation constructed during development by our Central Nervous System under the direction of our DNA, consists of a holographic representation arising from sensory input in the cerebellum and projected extraneurally in the brain ventricular fluid which has the chemical structure of liquid crystal. The structure of 3-D holographic Body Representation is then extrapolated by such cognitive instruments as boundarization, geometrization and gestalt organization upon the external environment which is perceived consequently as three dimensional. When the Body Representation collapses as in psychotic panic states. patients become terrified as they suddenly lose the perception of themselves and the world around them as three dimensional, solid in a reliably solid environment but feel suddenly that they are no longer a person but a disorganized blob. In our clinical practice we found serendipitously that the structure of three dimensionality can be restored even without medication by techniques involving stimulation of the body sensory system in the presence of a benevolent psychotherapist. Implications for Virtual Reality will be discussed.

Realistic expectations for public access defibrillation programs.

PubMed

Atkins, Dianne L

2010-06-01

Public access defibrillation programs have increased dramatically over the past 15 years. This review will focus on their effectiveness and operational characteristics and discuss the characteristics of successful programs, which can improve outcomes. Automated external defibrillators increase survival from cardiac arrest when used by a bystander. Recent studies show that the best outcomes are achieved when devices are placed in areas with a high frequency of cardiac arrest and there is ongoing supervision with emergency plans and cardiopulmonary resuscitation training. Programs are cost-effective under these circumstances, but become very inefficient when placed in areas of low risk. There are few adverse events related to the public access defibrillation programs and volunteers are not harmed. Unguided placement results in devices not being used and a decline in organizational structure of the program. As most cardiac arrests occur in the home, the impact on overall survival remains low. Automated external defibrillators are highly effective at reducing death from ventricular fibrillation and easy access in public areas is most effective. Placement must be prioritized based on public health impact and characteristics of the community.

Water/magma mass fractions in phreatomagmatic eruption plumes - constraints from the Grímsvötn 2011 eruption

NASA Astrophysics Data System (ADS)

Gudmundsson, M. T.; Pálsson, F.; Thordarson, T.; Hoskuldsson, A.; Larsen, G.; Hognadottir, T.; Oddsson, B.; Oladottir, B. A.; Gudnason, J.

2014-12-01

Explosive interaction of magma and water leads to vaporization and introduces external water vapor to volcanic plumes. Theoretical considerations on the effect of external water magma ratio on volcanic plumes indicate that plume buoyancy should be enhanced by external water fractions up to at least 30%, while fractions reaching 40% should lead to plume collapse. The basaltic VEI 4 eruption of Grímsvötn in May 2011 produced a 15-20 km high eruption plume and over 100 km wide umbrella cloud. External water interacted with the magma and entered the plume from the melting out of a 100-150 m deep ice cauldron that had acquired a volume of 0.1 km3 at the end of the eruption. About 0.7 km3 of tephra was produced in the eruption whereof about half was erupted in phreatomagmatic phases and the other half in magmatic phases. During the dry, magmatic phases melting was apparently not fast enough to supply sufficient external water to the vents to control the style of activity. The only source of external water was the melting out of the ice cauldron since no changes took place in the level of the larger, subglacial lake in the center of the Grímsvötn caldera, and no meltwater was drained from the caldera. The eruption site therefore had little or no hydrological connection with the adjacent subglacial lake. Water remaining at the eruption site at the end of the eruption was miniscule compared to the amount of ice melted. Hence, most of the meltwater was vaporized and carried away as a part of the eruption plume. About one third of the thermal energy of the magma erupted was used to melt, heat up and vaporize water. A large part of this water was released from the plume through condensation and re-freezing, manifested in hail-rich tephra deposited out to several kilometers from the vent. The data indicate that the external water/tephra mass ratio in the phreatomagmatic phases was 20-25%, but similar to 5% for the predominantly magmatic phases.

Effect of polluted water on soil and plant contamination by heavy metals in El-Mahla El-Kobra, Egypt

NASA Astrophysics Data System (ADS)

Kasem Mahmoud, Esawy; Ghoneim, Adel Mohamed

2016-04-01

The discharge of untreated waste water in Zefta drain and drain no. 5 is becoming a problem for many farmers in the El-Mahla El-Kobra area, Egypt. The discharged water contains high levels of contaminants considered hazardous to the ecosystem. Some plants, soil, water, and sediment samples were collected from the El-Mahla El-Kobra area to evaluate the contamination by heavy metals. The results showed that the heavy metals, pH, sodium adsorption ratio (SAR), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) in the water of Zefta drain and drain no. 5 exceeded permissible limits for irrigation. In rice and maize shoots grown in soils irrigated by contaminated water from Zefta drain and drain no. 5, the bioaccumulation factors for Cd, Pb, Zn, Cu, and Mn were higher than 1.0. The heavy metals content of irrigated soils from Zefta drain and drain no. 5 exceeded the upper limit of background heavy metals. In this study, the mean contaminant factor values of the drain no. 5 sediments revealed that Zn, Mn, Cu, Cd, Pb, and Ni > 6, indicating very high contamination. The bioaccumulation coefficient values of Cynodon dactylon, Phragmites australis, and Typha domingensis aquatic plants growing in Zefta drain are high. These species can be considered as hyperaccumulators for the decontamination of contaminated water.

Epidemiology of Benign External Hydrocephalus in Norway-A Population-Based Study.

PubMed

Wiig, Ulrikke S; Zahl, Sverre M; Egge, Arild; Helseth, Eirik; Wester, Knut

2017-08-01

Benign external hydrocephalus is defined as a rapidly increasing head circumference (occipitofrontal circumference) with characteristic radiological findings of increased subarachnoid cerebrospinal fluid spaces on neuroimaging. The incidence of benign external hydrocephalus has not been previously reported, and there is no available information on the ratio of benign external hydrocephalus in the population of hydrocephalic children. This study is retrospective and population-based study, geographically covering two health regions in the southern half of Norway with a total mean population of 3.34 million in the ten-year study period, constituting approximately 75% of the Norwegian population. Children with a head circumference crossing two percentiles, or greater than the 97.5th percentile, and with typical imaging findings of enlarged frontal subarachnoid spaces with or without enlarged ventricles were included. Children were excluded if they had a history of head trauma, intracranial hemorrhage, central nervous system infection, other known causes of hydrocephalus, or were born preterm defined as birth before 37 weeks of gestation. A total of 176 children fitting the criteria were identified, giving an incidence of 0.4 per 1000 live births. One hundred fifty-two (86.4%) of the patients were male, and mean age at referral was 7.3 months. Increasing head circumference was the main reason for referral in 158 (89.8%) patients and the only finding in 60 (34.1%) patients. Thirty-seven (21%) children had normal ventricles on imaging; the remainder had increased ventricular size. The incidence of pediatric hydrocephalus in Norway is reported to be 0.75 per 1000 live births, thus benign external hydrocephalus accounts for approximately 50% of hydrocephalic conditions in this population. The incidence of benign external hydrocephalus was found to be 0.4 per 1000 live births in this population. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

A novel thin-film transistor with step gate-overlapped lightly doped drain and raised source/drain design

NASA Astrophysics Data System (ADS)

Chien, Feng-Tso; Chen, Jian-Liang; Chen, Chien-Ming; Chen, Chii-Wen; Cheng, Ching-Hwa; Chiu, Hsien-Chin

2017-11-01

In this paper, a novel step gate-overlapped lightly doped drain (GOLDD) with raised source/drain (RSD) structure (SGORSD) is proposed for TFT electronic device application. The new SGORSD structure could obtain a low electric field at channel near the drain side owing to a step GOLDD design. Compared to the conventional device, the SGORSD TFT exhibits a better kink effect and higher breakdown performance due to the reduced drain electric field (D-EF). In addition, the leakage current also can be suppressed. Moreover, the device stability, such as the threshold voltage shift and drain current degradation under a high gate bias, is improved by the design of SGORSD structure. Therefore, this novel step GOLDD structure can be a promising design to be used in active-matrix flat panel electronics.

Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

PubMed

Connolly, J; Holden, N M

2017-12-01

Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO 2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from "wetlands drainage and rewetting". The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO 2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

PubMed

Connolly, J; Holden, N M

2017-12-01

Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality ( CCQ ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO 2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from "wetlands drainage and rewetting". The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO 2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

Comparative effect of tube drain on post operative inflammatory complications of impacted mandibular third molar surgery College Hospital, Ibadan, Nigeria.

PubMed

Obimakinde, O S; Fasola, A O; Arotiba, J T; Okoje, V N; Obiechina, A E

2010-09-01

Swelling, pain and trismus are acute reversible inflammatory complications of impacted mandibular third molar (M3) surgery. They contribute to the deterioration of quality of life and loss of several useful working hours. This study aimed to investigate whether the use of a surgical drain following M3 surgery can minimise these inflammatory complications. Eighty consecutive patients who gave consent were enrolled into the study. Patients were assigned into two groups (drain and no drain) by systematic sampling method which was modified to ensure matching of patients by age, sex and spatial relationship of the impacted mandibular third molar. The patients in the drain group (n=40) had a Foley's catheter drain inserted into the wound after the surgical procedure while the patients in the no drain group (n=40) had their wound closed without the use of drain. All patients had primary wound closure with 3.0 black silk sutures after the procedure. Demographic data, cheek dimension and maximal mouth opening were recorded before the procedure. Pain, swelling and trismus were evaluated in the two groups at 24 hours, 48 hours and 7th day after surgery. Post operative swelling and visual analogue scale score for pain were comparatively lesser in the drain group patients. The maximal interincisal distance was also more in the drain group patients. The findings from this study indicated that there is a significant benefit of using a surgical drain in minimising postoperative oedema, pain and trismus following surgical removal of impacted mandibular third molar.

Carriers of the hypertrophic cardiomyopathy MYBPC3 mutation are characterized by reduced myocardial efficiency in the absence of hypertrophy and microvascular dysfunction.

PubMed

Timmer, Stefan A J; Germans, Tjeerd; Brouwer, Wessel P; Lubberink, Mark; van der Velden, Jolanda; Wilde, Arthur A M; Christiaans, Imke; Lammertsma, Adriaan A; Knaapen, Paul; van Rossum, Albert C

2011-12-01

Next to left ventricular (LV) hypertrophy, hypertrophic cardiomyopathy (HCM) is characterized by microvascular dysfunction and reduced myocardial external efficiency (MEE). Insights into the presence of these abnormalities as early markers of disease are of clinical importance in risk stratification, and development of therapeutic approaches. Therefore, the aim was to investigate myocardial perfusion and energetics in genotype-positive, phenotype-negative HCM subjects (carriers). Fifteen carriers of an MYBPC3 mutation underwent [(15)O]water positron emission tomography (PET) to assess myocardial blood flow (MBF). [(11)C]acetate PET was performed to obtain myocardial oxygen consumption (MVO(2)). By use of cardiovascular magnetic resonance imaging, LV volumes and mass were defined to calculate MEE, i.e. the ratio between external work and MVO(2). Eleven healthy, genotype-negative, family relatives underwent similar scanning protocols to serve as a control group. Left ventricular mass was comparable between carriers and controls (93 ± 25 vs. 99 ± 21 g, P= 0.85), as was MBF at rest (1.19 ± 0.34 vs. 1.18 ± 0.32 mL min(-1) g(-1), P= 0.92), and during hyperaemia (3.87 ± 0.75 vs. 3.96 ± 0.86 mL min(-1) g(-1), P= 0.77). Myocardial oxygen consumption averaged 0.137 ± 0.057 mL min(-1) g(-1) in carriers and was not significantly different from controls (0.125 ± 0.043 mL min(-1) g(-1), P= 0.29). Cardiac work, however, was slightly reduced in carriers (7398 ± 1384 vs. 9139 ± 2484 mmHg mL in controls, P= 0.08). As a consequence, MEE was significantly decreased in carriers (27 ± 10 vs. 36 ± 8% in controls, P= 0.02). Carriers display reduced myocardial work generation in relation to oxygen consumption, in the absence of hypertrophy and flow abnormalities. Hence, impaired myocardial energetics may constitute a primary component of HCM pathogenesis.

Automated External Defibrillators and Survival After In-Hospital Cardiac Arrest

PubMed Central

Chan, Paul S.; Krumholz, Harlan M.; Spertus, John A.; Jones, Philip G.; Cram, Peter; Berg, Robert A.; Peberdy, Mary Ann; Nadkarni, Vinay; Mancini, Mary E.; Nallamothu, Brahmajee K.

2013-01-01

Context Automated external defibrillators (AEDs) improve survival from out-of-hospital cardiac arrests, but data on their effectiveness in hospitalized patients are limited. Objective To evaluate the association of AED use and survival for in-hospital cardiac arrest. Design, Setting, Patients Cohort study of 11,695 hospitalized patients with cardiac arrests between January 1, 2000 and August 26, 2008 at 204 hospitals following the introduction of AEDs on general hospital wards. Main Outcome Measure Survival to hospital discharge by AED use, using multivariable hierarchical regression analyses to adjust for patient factors and hospital site. Results Of 11,695 patients, 9616 (82.2%) had non-shockable rhythms (asystole and pulseless electrical activity) and 2079 (17.8%) had shockable rhythms (ventricular fibrillation and pulseless ventricular tachycardia). AEDs were used in 4515 (38.6%) patients. Overall, 2117 (18.1%) patients survived to hospital discharge. Within the entire study population, AED use was associated with a lower rate of survival after in-hospital cardiac arrest compared with no AED use (16.3% vs. 19.3%; adjusted rate ratio (RR), 0.85; 95% confidence interval (CI), 0.78–0.92; P<0.001). Among cardiac arrests due to non-shockable rhythms, AED use was associated with lower survival (10.4% vs. 15.4%; adjusted RR, 0.74; 95% CI, 0.65–0.83; P<.001). In contrast, for cardiac arrests due to shockable rhythms, AED use was not associated with survival (38.4% vs. 39.8%; adjusted RR, 1.00; 95% CI, 0.88–1.13; P=0.99). These patterns were consistently observed in both monitored and non-monitored hospital units where AEDs were used, after matching patients to the individual units in each hospital where the cardiac arrest occurred, and with a propensity score analysis. Conclusion Use of AEDs in hospitalized patients with cardiac arrest is not associated with improved survival. PMID:21078809

Comparison of Venous Return Characteristics with Right Ventricular Mechanics During Cephalic Fluid Shift

NASA Technical Reports Server (NTRS)

Elliott, Morgan; Martin, David

2015-01-01

For my summer internship project, I organized a pilot study to analyze the effects of a cephalic fluid shift on venous return and right ventricular mechanics to increase right ventricular and venous knowledge. To accomplish this pilot study, I wrote a testing protocol, obtained Institutional Review Board (IRB) approval, completed subject payment forms, lead testing sessions, and analyzed the data. This experiment used -20deg head down tilt (20 HDT) as the ground based simulation for the fluid shift that occurs during spaceflight and compared it to data obtained from the seated and supine positions. Using echocardiography, data was collected for the right ventricle, hepatic vein, internal jugular vein, external jugular vein, and inferior vena cava. Additionally, non-invasive venous pressure measurements, similar to those soon to be done in-orbit, were collected. It was determined that the venous return from below the heard is increased during 20 HDT, which was supported by increased hepatic vein velocities, increased right ventricular inflow, and increased right ventricular strain at 20 HDT relative to seated values. Jugular veins in the neck undergo an increase in pressure and area, but no significant increase in flow, relative to seated values when a subject is tilted 20 HDT. Contrary to the initial expectations based on this jugular flow, there was no significant increase in central venous pressure, as evidenced by no change in Doppler indices for right arterial pressure or inferior vena cava diameter. It is suspected that these differences in pressure are due to the hydrostatic pressure indifference point shifting during tilt; there is a potential for a similar phenomenon with microgravity. This data will hopefully lead to a more in-depth understanding of the response of the body to microgravity and how those relate to the previously mentioned cardiovascular risk of fluid shift that is associated with spaceflight. These results were presented in greater detail to the Cardiovascular Laboratory and the Space Life Science Summer Institute, which helped me prepare for future graduate school research presentations. This internship allowed me to apply and expand the anatomy, physiology, and mechanics information I learned during my undergraduate degree in Biomedical Engineering to the cardiovascular system with the unique zero gravity perspective. Additionally, I was able to develop skills with data analysis techniques involving speckle tracking for ventricular strain and Doppler waveforms for blood velocities. Additionally, I was able to expand upon my previous work in the Cardiovascular Laboratory by writing a literature review on a data analysis project I completed last summer. Ultimately, this internship and venous relationship comparison project provided me with a significant learning experience and additional skill sets, which are applicable to my goals of attaining a Ph.D. in biomedical engineering with a focus on tissue engineering and the cardiovascular system.

77 FR 70382 - Airworthiness Directives; Eurocopter France Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... the fuel tank draining system. This proposed AD is prompted by a closed fuel tank drain that, in the... fuel tank compartments' draining system. FAA's Determination These helicopters have been approved by... buoyancy fixed parts, the ASBs describe procedures to modify the fuel tank draining system by removing...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 29.1021 Section 29.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 25.1021 Section 25.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 29.1021 - Oil system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Oil system drains. 29.1021 Section 29.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 25.1021 - Oil system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Oil system drains. 25.1021 Section 25.1021 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... drains) must be provided to allow safe drainage of the oil system. Each drain must— (a) Be accessible...

14 CFR 125.139 - Oil system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Oil system drains. 125.139 Section 125.139....139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system. ...

14 CFR 125.139 - Oil system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Oil system drains. 125.139 Section 125.139....139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system. ...

14 CFR 125.139 - Oil system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Oil system drains. 125.139 Section 125.139....139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system. ...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

46 CFR 45.157 - Scuppers and gravity drains.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

Independent Orbiter Assessment (IOA): Analysis of the purge, vent and drain subsystem

NASA Technical Reports Server (NTRS)

Bynum, M. C., III

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter PV and D (Purge, Vent and Drain) Subsystem hardware. The PV and D Subsystem controls the environment of unpressurized compartments and window cavities, senses hazardous gases, and purges Orbiter/ET Disconnect. The subsystem is divided into six systems: Purge System (controls the environment of unpressurized structural compartments); Vent System (controls the pressure of unpressurized compartments); Drain System (removes water from unpressurized compartments); Hazardous Gas Detection System (HGDS) (monitors hazardous gas concentrations); Window Cavity Conditioning System (WCCS) (maintains clear windows and provides pressure control of the window cavities); and External Tank/Orbiter Disconnect Purge System (prevents cryo-pumping/icing of disconnect hardware). Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Four of the sixty-two failure modes analyzed were determined as single failures which could result in the loss of crew or vehicle. A possible loss of mission could result if any of twelve single failures occurred. Two of the criticality 1/1 failures are in the Window Cavity Conditioning System (WCCS) outer window cavity, where leakage and/or restricted flow will cause failure to depressurize/repressurize the window cavity. Two criticality 1/1 failures represent leakage and/or restricted flow in the Orbiter/ET disconnect purge network which prevent cryopumping/icing of disconnect hardware. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

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

Seo, Jooyeok; Lee, Chulyeon; Han, Hyemi

We report a tactile touch sensor based on a planar liquid crystal-gated-organic field-effect transistor (LC-g-OFET) structure. The LC-g-OFET touch sensors were fabricated by forming the 10 μm thick LC layer (4-cyano-4{sup ′}-pentylbiphenyl - 5CB) on top of the 50 nm thick channel layer (poly(3-hexylthiophene) - P3HT) that is coated on the in-plane aligned drain/source/gate electrodes (indium-tin oxide - ITO). As an external physical stimulation to examine the tactile touch performance, a weak nitrogen flow (83.3 μl/s) was employed to stimulate the LC layer of the touch device. The LC-g-OFET device exhibited p-type transistor characteristics with a hole mobility of 1.5more » cm{sup 2}/Vs, but no sensing current by the nitrogen flow touch was measured at sufficiently high drain (V{sub D}) and gate (V{sub G}) voltages. However, a clear sensing current signal was detected at lower voltages, which was quite sensitive to the combination of V{sub D} and V{sub G}. The best voltage combination was V{sub D} = −0.2 V and V{sub G} = −1 V for the highest ratio of signal currents to base currents (i.e., signal-to-noise ratio). The change in the LC alignment upon the nitrogen flow touch was assigned as the mechanism for the present LC-g-OFET touch sensors.« less

Tunable Electrical and Optical Characteristics in Monolayer Graphene and Few-Layer MoS2 Heterostructure Devices.

PubMed

Rathi, Servin; Lee, Inyeal; Lim, Dongsuk; Wang, Jianwei; Ochiai, Yuichi; Aoki, Nobuyuki; Watanabe, Kenji; Taniguchi, Takashi; Lee, Gwan-Hyoung; Yu, Young-Jun; Kim, Philip; Kim, Gil-Ho

2015-08-12

Lateral and vertical two-dimensional heterostructure devices, in particular graphene-MoS2, have attracted profound interest as they offer additional functionalities over normal two-dimensional devices. Here, we have carried out electrical and optical characterization of graphene-MoS2 heterostructure. The few-layer MoS2 devices with metal electrode at one end and monolayer graphene electrode at the other end show nonlinearity in drain current with drain voltage sweep due to asymmetrical Schottky barrier height at the contacts and can be modulated with an external gate field. The doping effect of MoS2 on graphene was observed as double Dirac points in the transfer characteristics of the graphene field-effect transistor (FET) with a few-layer MoS2 overlapping the middle part of the channel, whereas the underlapping of graphene have negligible effect on MoS2 FET characteristics, which showed typical n-type behavior. The heterostructure also exhibits a strongest optical response for 520 nm wavelength, which decreases with higher wavelengths. Another distinct feature observed in the heterostructure is the peak in the photocurrent around zero gate voltage. This peak is distinguished from conventional MoS2 FETs, which show a continuous increase in photocurrent with back-gate voltage. These results offer significant insight and further enhance the understanding of the graphene-MoS2 heterostructure.

Pontine infarction caused by medial branch injury of the basilar artery as a rare complication of cisternal drain placement.

PubMed

Horiuchi, Tetsuyoshi; Yamamoto, Yasunaga; Kuroiwa, Masafumi; Rahmah, Nunung Nur; Hongo, Kazuhiro

2012-04-01

We present a rare complication of cisternal drain placement during aneurysm surgery. A ruptured anterior communicating artery aneurysm was clipped through a right pterional approach. A cisternal drain was inserted from the retro-carotid to the prepontine cistern. Postoperatively, a left-sided paresis of the upper extremity had developed. A CT brain scan revealed that the drain was located between the pons and the basilar artery, resulting in a pontine infarction. Vascular neurosurgeons should keep this complication in mind when placing a cisternal drain tube. The drain tube should not be inserted too deep into the prepontine cistern. Copyright © 2011 Elsevier Ltd. All rights reserved.

Surgical ablation of ventricular tachycardia secondary to congenital ventricular septal aneurysm.

PubMed

Graffigna, A; Minzioni, G; Ressia, L; Vigano, M

1994-04-01

Three patients underwent surgical ablation for ventricular tachycardia resulting from an aneurysm of the membranous portion of the ventricular septum. Two patients had a definite history of cardiac murmur during infancy, and one of them was found at the time of operation to have a left-to-right shunt through the apex of the aneurysm. The earliest ventricular activation sites were located around the neck of the aneurysm and were ablated in 1 patient by encircling the endocardial ventriculotomy and by cryoablation in the remaining 2. After focus resection had been completed, aneurysm resection and ventricular septal reconstruction were performed. All patients were alive and free of ventricular tachycardia and did not need medication as of 61, 66, and 88 months postoperatively. Spontaneous closure of a ventricular septal defect may lead to the formation of an aneurysm in the ventricular septum that may sustain ventricular tachycardias. Such arrhythmias can be effectively treated using electrically guided surgical techniques.

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

Han, Dong-Suk; Kang, Yu-Jin; Park, Jae-Hyung

Highlights: • We developed and investigated source/drain electrodes in oxide TFTs. • The Mo S/D electrodes showed good output characteristics. • Intrinsic TFT parameters were calculated by the transmission line method. - Abstract: This paper investigates the feasibility of a low-resistivity electrode material (Mo) for source/drain (S/D) electrodes in thin film transistors (TFTs). The effective resistances between Mo source/drain electrodes and amorphous zinc–tin-oxide (a-ZTO) thin film transistors were studied. Intrinsic TFT parameters were calculated by the transmission line method (TLM) using a series of TFTs with different channel lengths measured at a low source/drain voltage. The TFTs fabricated with Momore » source/drain electrodes showed good transfer characteristics with a field-effect mobility of 10.23 cm{sup 2}/V s. In spite of slight current crowding effects, the Mo source/drain electrodes showed good output characteristics with a steep rise in the low drain-to-source voltage (V{sub DS}) region.« less

Rupture disc

DOEpatents

Newton, Robert G.

1977-01-01

The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 25.999 - Fuel system drains.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel system drains. 25.999 Section 25.999... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System Components § 25.999 Fuel system drains. (a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains. (b...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

14 CFR 23.999 - Fuel system drains.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel system drains. 23.999 Section 23.999... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Fuel System Components § 23.999 Fuel system drains. (a) There must be at least one drain to allow safe drainage of the entire...

Nutrient Drain Associated with Hardwood Plantation Culture

Treesearch

James B. Baker

1978-01-01

Past research and a tentative evaluation indicate that nutrient drain and possible site degradation could occur in southern hardwood plantations. The extent of nutrient drain on a given site would depend on the species, length of the rotation, and harvesting system used. The evaluation for cottonwood plantations in Mississippi indicates that nutrient drain is most...

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.

Cardiac function in children with premature ventricular contractions: the effect of omega-3 polyunsaturated fatty acid supplementation.

PubMed

Oner, Taliha; Ozdemir, Rahmi; Doksöz, Onder; Genc, Dildar B; Guven, Baris; Demirpence, Savas; Yilmazer, Murat M; Yozgat, Yilmaz; Mese, Timur; Tavli, Vedide

2018-07-01

Premature ventricular contractions are accepted as benign in structurally normal hearts. However, reversible cardiomyopathy can sometimes develop. Omega-3 polyunsaturated fatty acids have anti-arrhythmic properties in animals and humans.AimWe evaluated left ventricular function in children with premature ventricular contractions with normal cardiac anatomy and assessed the impact of omega-3 fatty acid supplementation on left ventricular function in a prospective trial. A total of 25 patients with premature ventricular contraction, with more than 2% premature ventricular contractions on 24-hour Holter electrocardiography, and 30 healthy patients were included into study. All patients underwent electrocardiography, left ventricular M-mode echocardiography, and myocardial performance index testing. Patients with premature ventricular contraction were given omega-3 fatty acids at a dose of 1 g/day for 3 months, and control echocardiography and 24-hour Holter electrocardiography were performed. Neither placebo nor omega-3 fatty acids were given to the control group. Compared with the values of the control group, the patients with premature ventricular contraction had significantly lower fractional shortening. The myocardial performance index decreased markedly in the patient groups. The mean heart rate and mean premature ventricular contraction percentage of Group 2 significantly decreased in comparison with their baseline values after the omega-3 supplementation. In conclusion, premature ventricular contractions can lead to systolic cardiac dysfunction in children. Omega-3 supplementation may improve cardiac function in children with premature ventricular contractions. This is the first study conducted in children to investigate the possible role of omega-3 fatty acid supplementation on treatment of premature ventricular contractions.

Drain Tube-Induced Jejunal Penetration Masquerading as Bile Leak following Whipple's Operation.

PubMed

Bae, Sang Ho; Lee, Tae Hoon; Lee, Sae Hwan; Lee, Suck-Ho; Park, Sang-Heum; Kim, Sun-Joo; Kim, Chang Ho

2011-05-01

A 70-year-old man had undergone pancreaticoduodenectomy due to a distal common bile duct malignancy. After the operation, serous fluid discharge decreased from two drain tubes in the retroperitoneum. Over four weeks, the appearance of the serous fluid changed to a greenish bile color and the patient persistently drained over 300 ml/day. Viewed as bile leak at the choledochojejunostomy, treatment called for endoscopic diagnosis and therapy. Cap-fitted forward-viewing endoscopy demonstrated that the distal tip of a pancreatic drain catheter inserted at the pancreaticojejunostomy site had penetrated the opposite jejunum wall. One of the drain tubes primarily placed in the retroperitoneum had also penetrated the jejunum wall, with the distal tip positioned near the choledochojejunostomy site. No leak of contrast appeared beyond the jejunum or anastomosis site. Following repositioning of a penetrating catheter of the pancreaticojejunostomy, four days later, the patient underwent removal of two drain tubes without additional complications. In conclusion, the distal tip of the catheter, placed to drain pancreatic juice, penetrated the jejunum wall and may have caused localized perijejunal inflammation. The other drain tube, placed in the retroperitoneal space, might then have penetrated the inflamed wall of the jejunum, allowing persistent bile drainage via the drain tube. The results masqueraded as bile leakage following pancreaticoduodenectomy.

Insulation Failure of the Linox Defibrillator Lead: A Case Report and Retrospective Review of a Single Center Experience.

PubMed

Howe, Andrew J; McKeag, Nicholas A; Wilson, Carol M; Ashfield, Kyle P; Roberts, Michael J

2015-06-01

Implantable cardioverter defibrillator (ICD) lead insulation failure and conductor externalization have been increasingly reported. The 7.8F silicon-insulated Linox SD and Linox S ICD leads (Biotronik, Berlin, Germany) were released in 2006 and 2007, respectively, with an estimated 85,000 implantations worldwide. A 39-year-old female suffered an out-of-hospital ventricular fibrillation (VF) arrest with successful resuscitation. An ICD was implanted utilizing a single coil active fixation Linox(Smart) S lead (Biotronik, Berlin, Germany). A device-triggered alert approximately 3 years after implantation confirmed nonphysiological high rate sensing leading to VF detection. A chest X-ray showed an abnormality of the ICD lead and fluoroscopic screening confirmed conductor externalization proximal to the defibrillator coil. In view of the combined electrical and fluoroscopic abnormalities, urgent lead extraction and replacement were performed. A review of Linox (Biotronik) and Vigila (Sorin Group, Milan, Italy) lead implantations within our center (n = 98) identified 3 additional patients presenting with premature lead failure, 2 associated with nonphysiological sensed events and one associated with a significant decrease in lead impedance. All leads were subsequently removed and replaced. This case provides a striking example of insulation failure affecting the Linox ICD lead and, we believe, is the first to demonstrate conductor externalization manifesting both electrical and fluoroscopic abnormalities. © 2015 Wiley Periodicals, Inc.

Drain blocking: an effective treatment for reducing dissolved organic carbon loss and water discolouration in a drained peatland.

PubMed

Wallage, Zoe E; Holden, Joseph; McDonald, Adrian T

2006-08-31

Peatlands are an important terrestrial carbon store. However, heightened levels of degradation in response to environmental change have resulted in an increased loss of dissolved organic carbon (DOC) and an associated rise in the level of discolouration in catchment waters. A significant threat to peatland sustainability has been the installation of artificial drainage ditches. However, recent restoration schemes have pursued drain blocking as a possible strategy for reducing degradation, fluvial carbon loss and water discolouration. This paper investigates the effect of open cut drainage and the impact of drain blocking on DOC and colour dynamics in blanket peat soil-water solutions. Three treatments (intact peat, drained peat and drain-blocked peat) were monitored in an upland blanket peat catchment in the UK. DOC and colour values were significantly higher on the drained slopes compared with those of the intact peat, which in turn had greater DOC and colour values than the drain-blocked slopes. Consequently, drain blocking is shown to be a highly successful technique in reducing both the DOC concentration and level of discolouration in soil waters, even to values lower than those observed for the intact site, which suggests a process of store exhaustion and flushing may operate. The colour per carbon unit (C/C) ratio was significantly higher at the drain-blocked site than either the intact or the drained treatments, while the E4/E6 ratio (fulvic acid/humic acid) was significantly lower at the blocked site compared to the two other treatments. The high C/C and low E4/E6 ratios indicate that drain blocking also modifies the composition of DOC, such that darker-coloured humic substances become more dominant compared to the intact site. This implies disturbance to DOC production and/or transportation processes operating within the peat.

Generation of airborne Listeria innocua from model floor drains.

PubMed

Berrang, Mark E; Frank, Joseph F

2012-07-01

Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 10(8) cells per ml of phosphate-buffered saline and 10(4) attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

Drain placement can be safely omitted after the majority of robotic partial nephrectomies.

PubMed

Abaza, Ronney; Prall, David

2013-03-01

Drain placement after partial nephrectomy is considered standard but it is based on routine and not on evidence. With experience we performed robotic partial nephrectomy and routinely omitted a drain even with significant collecting system violation. We have rarely used drains after robotic partial nephrectomy for several years, and we report our outcomes. We reviewed a single surgeon, prospective database of all robotic partial nephrectomies from February 2008 to March 2012, including the characteristics of those with and without a drain. The 150 patients underwent a total of 160 robotic partial nephrectomy procedures with a drain used in 11 patients and omitted in 93%. Mean patient age was 57 years (range 22 to 89), mean American Society of Anesthesiologists score was 2.8 (range 2 to 4) and mean body mass index was 32 kg/m(2) (range 18 to 54). Values were similar in patients with and without a drain. In patients without a drain and in those with a drain mean tumor size was 3.5 cm (range 1.0 to 11.0) and 4.6 cm (range 1.1 to 8.6), and mean R.E.N.A.L. (radius, exophytic/endophytic, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines, hilar tumor touching main renal artery or vein) nephrometry score was 7.8 (range 4 to 12) and 8.8 (range 6 to 11), respectively. Collecting system violation occurred in 88 patients (59%), including 78 without a drain. Two patients (1.3%) required transfusion with no intervention for bleeding. All except 5 patients (97%) were discharged home on postoperative day 1 with all drains removed before discharge. In 2 patients (1.3%) without a drain small urinomas without infection developed more than 2 weeks postoperatively, which were treated with a week of Foley catheter drainage and percutaneous drainage, respectively. Drain placement after robotic partial nephrectomy can be routinely omitted with a low rate of urine leaks, which can be managed safely when they rarely occur. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum.

PubMed

Martini, Bortolo; Trevisi, Nicola; Martini, Nicolò; Zhang, Li

2015-01-01

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches.

Right Ventricular Outflow Tract Tachycardia with Structural Abnormalities of the Right Ventricle and Left Ventricular Diverticulum

PubMed Central

Martini, Bortolo; Trevisi, Nicola; Martini, Nicolò; Zhang, Li

2015-01-01

A 43-year-old woman presented to the emergency room with a sustained ventricular tachycardia (VT). ECG showed a QRS in left bundle branch block morphology with inferior axis. Echocardiography, ventricular angiography, and cardiac magnetic resonance imaging (CMRI) revealed a normal right ventricle and a left ventricular diverticulum. Electrophysiology studies with epicardial voltage mapping identified a large fibrotic area in the inferolateral layer of the right ventricular wall and a small area of fibrotic tissue at the anterior right ventricular outflow tract. VT ablation was successfully performed with combined epicardial and endocardial approaches. PMID:26509086

Catheter ablation for premature ventricular contractions and ventricular tachycardia in patients with heart failure.

PubMed

Kumar, Saurabh; Stevenson, William G; John, Roy M

2014-09-01

Ventricular arrhythmias (VA) are a significant contributor to morbidity and mortality in patients with heart failure (HF). Implantable cardioverter defibrillators are effective in reducing mortality, but do not prevent arrhythmia recurrence. There is increasing recognition that frequent premature ventricular contractions or repetitive ventricular tachycardia may also lead to new onset ventricular dysfunction or deterioration of ventricular function in patients with pre-existing HF. Suppression of the arrhythmia may lead to recovery of ventricular function. Catheter ablation has emerged as a safe and effective treatment option for reducing arrhythmia recurrence and for suppression of PVCs but its efficacy is governed by the nature of the arrhythmias, the underlying HF substrate and the accessibility of the arrhythmia substrates to ablation.

Engineering human ventricular heart muscles based on a highly efficient system for purification of human pluripotent stem cell-derived ventricular cardiomyocytes.

PubMed

Li, Bin; Yang, Hui; Wang, Xiaochen; Zhan, Yongkun; Sheng, Wei; Cai, Huanhuan; Xin, Haoyang; Liang, Qianqian; Zhou, Ping; Lu, Chao; Qian, Ruizhe; Chen, Sifeng; Yang, Pengyuan; Zhang, Jianyi; Shou, Weinian; Huang, Guoying; Liang, Ping; Sun, Ning

2017-09-29

Most infarctions occur in the left anterior descending coronary artery and cause myocardium damage of the left ventricle. Although current pluripotent stem cells (PSCs) and directed cardiac differentiation techniques are able to generate fetal-like human cardiomyocytes, isolation of pure ventricular cardiomyocytes has been challenging. For repairing ventricular damage, we aimed to establish a highly efficient purification system to obtain homogeneous ventricular cardiomyocytes and prepare engineered human ventricular heart muscles in a dish. The purification system used TALEN-mediated genomic editing techniques to insert the neomycin or EGFP selection marker directly after the myosin light chain 2 (MYL2) locus in human pluripotent stem cells. Purified early ventricular cardiomyocytes were estimated by immunofluorescence, fluorescence-activated cell sorting, quantitative PCR, microelectrode array, and patch clamp. In subsequent experiments, the mixture of mature MYL2-positive ventricular cardiomyocytes and mesenchymal cells were cocultured with decellularized natural heart matrix. Histological and electrophysiology analyses of the formed tissues were performed 2 weeks later. Human ventricular cardiomyocytes were efficiently isolated based on the purification system using G418 or flow cytometry selection. When combined with the decellularized natural heart matrix as the scaffold, functional human ventricular heart muscles were prepared in a dish. These engineered human ventricular muscles can be great tools for regenerative therapy of human ventricular damage as well as drug screening and ventricular-specific disease modeling in the future.

Magnetic resonance imaging during untreated ventricular fibrillation reveals prompt right ventricular overdistention without left ventricular volume loss.

PubMed

Berg, Robert A; Sorrell, Vincent L; Kern, Karl B; Hilwig, Ronald W; Altbach, Maria I; Hayes, Melinda M; Bates, Kathryn A; Ewy, Gordon A

2005-03-08

Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreated VF, thereby overdistending the right ventricle and apparently decreasing left ventricular size. Therefore, inadequate left ventricular stroke volume after defibrillation from prolonged VF has been postulated as a major contributor to the development of pulseless rhythms. Ventricular dimensions were determined by MRI for 30 minutes of untreated VF in a closed-chest, closed-pericardium model in 6 swine. Within 1 minute of untreated VF, mean right ventricular volume increased by 29% but did not increase thereafter. During the first 5 minutes of untreated VF, mean left ventricular volume increased by 34%. Between 20 and 30 minutes of VF, stone heart occurred as manifested by dramatic thickening of the myocardium and concomitant substantial decreases in left ventricular volume. In this closed-chest swine model of VF, substantial right ventricular volume changes occurred early and did not result in smaller left ventricular volumes. The changes in ventricular volumes before the late development of stone heart do not explain why defibrillation from brief duration VF (<5 minutes) typically results in a pulsatile rhythm with return of spontaneous circulation, whereas defibrillation from prolonged VF (5 to 15 minutes) does not.

Inappropriate left ventricular mass and poor outcomes in patients with angina pectoris and normal ejection fraction.

PubMed

Huang, Bao-Tao; Peng, Yong; Liu, Wei; Zhang, Chen; Huang, Fang-Yang; Wang, Peng-Ju; Zuo, Zhi-Liang; Liao, Yan-Biao; Chai, Hua; Li, Qiao; Zhao, Zhen-Gang; Luo, Xiao-Lin; Ren, Xin; Huang, Kai-Sen; Meng, Qing-Tao; Chen, Chi; Huang, De-Jia; Chen, Mao

2015-03-01

Although inappropriate left ventricular mass has been associated with clustered cardiac geometric and functional abnormalities, its predictive value in patients with coronary artery disease is still unknown. This study examined the association of inappropriate left ventricular mass with clinical outcomes in patients with angina pectoris and normal ejection fraction. Consecutive patients diagnosed with angina pectoris whose ejection fraction was normal were recruited from 2008 to 2012. Inappropriate left ventricular mass was determined when the ratio of actual left ventricular mass to the predicted one exceeded 150%. The primary endpoint was a composite of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. Clinical outcomes between the inappropriate and appropriate left ventricular mass group were compared before and after propensity matching. Of the total of 1515 participants, 18.3% had inappropriate left ventricular mass. Patients with inappropriate left ventricular mass had a higher composite event rate compared with those with appropriate left ventricular mass (11.2 vs. 6.6%, P=0.010). Multivariate Cox regression analyses showed that inappropriate left ventricular mass was an independent risk factor for adverse events (adjusted hazard ratio, 1.59; 95% confidence interval, 1.03-2.45; P=0.035). The worse outcome in patients with inappropriate left ventricular mass was further validated in a propensity matching cohort and patients with the traditional definition of left ventricular hypertrophy. Inappropriate left ventricular mass was associated with an increased risk of adverse events in patients with angina pectoris and normal ejection fraction.

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2012 CFR

2012-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2013 CFR

2013-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2011 CFR

2011-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2014 CFR

2014-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

Responses of Young Slash Pine on Poorly Drained to Somewhat Poorly Drained Silt Loam Soils to Site Preparation and Fertilization Treatments

Treesearch

James D. Haywood

1995-01-01

Slash pines (Pinus elliottii Engelm. var. elliottii) were planted on poorly drained Wrightsville and somewhat poorly drained Vidrine silt loam soils in southwest Louisiana. Neither flat disking nor bedding increased pine growth and yield substantially after nine growing seasons, but broadcast application of triple superphoshate...

7 CFR 58.416 - Cheese vats, tanks and drain tables.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Cheese vats, tanks and drain tables. 58.416 Section 58... Service 1 Equipment and Utensils § 58.416 Cheese vats, tanks and drain tables. (a) The vats, tanks and drain tables used for making cheese should be of metal construction with adequate jacket capacity for...

7 CFR 58.416 - Cheese vats, tanks and drain tables.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Cheese vats, tanks and drain tables. 58.416 Section 58... Service 1 Equipment and Utensils § 58.416 Cheese vats, tanks and drain tables. (a) The vats, tanks and drain tables used for making cheese should be of metal construction with adequate jacket capacity for...

30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

Code of Federal Regulations, 2010 CFR

2010-07-01

... precipitation event. (b) Rock-core chimney drains. A rock-core chimney drain may be used in a head-of-hollow... not located in an area containing intermittent or perennial streams. A rock-core chimney drain may be... is diverted around the fill. The alternative rock-core chimney drain system shall be incorporated...

Method of draining water through a solid waste site without leaching

DOEpatents

Treat, Russell L.; Gee, Glendon W.; Whyatt, Greg A.

1993-01-01

The present invention is a method of preventing water from leaching solid waste sites by preventing atmospheric precipitation from contacting waste as the water flows through a solid waste site. The method comprises placing at least one drain hole through the solid waste site. The drain hole is seated to prevent waste material from entering the drain hole, and the solid waste site cover material is layered and graded to direct water to flow toward the drain hole and to soil beneath the waste site.

Minimally invasive surgical technique for tethered surgical drains

PubMed Central

Hess, Shane R; Satpathy, Jibanananda; Waligora, Andrew C; Ugwu-Oju, Obinna

2017-01-01

A feared complication of temporary surgical drain placement is from the technical error of accidentally suturing the surgical drain into the wound. Postoperative discovery of a tethered drain can frequently necessitate return to the operating room if it cannot be successfully removed with nonoperative techniques. Formal wound exploration increases anesthesia and infection risk as well as cost and is best avoided if possible. We present a minimally invasive surgical technique that can avoid the morbidity associated with a full surgical wound exploration to remove a tethered drain when other nonoperative techniques fail. PMID:28400669

Method of draining water through a solid waste site without leaching

DOEpatents

Treat, R.L.; Gee, G.W.; Whyatt, G.A.

1993-02-02

The present invention is a method of preventing water from leaching solid waste sites by preventing atmospheric precipitation from contacting waste as the water flows through a solid waste site. The method comprises placing at least one drain hole through the solid waste site. The drain hole is seated to prevent waste material from entering the drain hole, and the solid waste site cover material is layered and graded to direct water to flow toward the drain hole and to soil beneath the waste site.

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

Leakage current conduction in metal gate junctionless nanowire transistors

NASA Astrophysics Data System (ADS)

Oproglidis, T. A.; Karatsori, T. A.; Barraud, S.; Ghibaudo, G.; Dimitriadis, C. A.

2017-05-01

In this paper, the experimental off-state drain leakage current behavior is systematically explored in n- and p-channel junctionless nanowire transistors with HfSiON/TiN/p+-polysilicon gate stack. The analysis of the drain leakage current is based on experimental data of the gate leakage current. It has been shown that the off-state drain leakage current in n-channel devices is negligible, whereas in p-channel devices it is significant and dramatically increases with drain voltage. The overall results indicate that the off-state drain leakage current in p-channel devices is mainly due to trap-assisted Fowler-Nordheim tunneling of electrons through the gate oxide of electrons from the metal gate to the silicon layer near the drain region.

Surgical site infections following craniotomy focusing on possible post-operative acquisition of infection: prospective cohort study.

PubMed

Sneh-Arbib, O; Shiferstein, A; Dagan, N; Fein, S; Telem, L; Muchtar, E; Eliakim-Raz, N; Rubinovitch, B; Rubin, G; Rappaport, Z H; Paul, M

2013-12-01

Neurosurgery is characterized by a prolonged risk period for surgical site infection (SSI), mainly related to the presence of cerebrospinal fluid (CSF) drains. We aimed to examine factors associated with post-neurosurgical SSIs, focusing on post-operative factors. A prospective cohort study was conducted in a single center over a period of 18 months in Israel. Included were adult patients undergoing clean or clean-contaminated craniotomy, including craniotomies with external CSF drainage or shunts. SSIs were defined by the Centers for Disease Control and Prevention (CDC) criteria for healthcare-associated infections. All patients were followed up for 90 days and those with foreign body insertion for 1 year. We compared patients with and without SSI. A multivariable regression analysis for SSI was conducted including uncorrelated variables significantly associated with SSI. A total of 502 patients were included, with 138 (27.5%) undergoing emergent or urgent craniotomy. The overall SSI rate was 5.6% (28 patients), of which 3.2% (16 patients) were intracerebral. Non-elective surgery, external CSF drainage/monitoring devices, re-operation, and post-operative respiratory failure were independently associated with subsequent SSI. External CSF devices was the only significant risk factor for intracerebral SSIs (p < 0.001). Internal shunts or other foreign body insertions were not associated with SSIs. A phenotypically identical isolate to that causing the SSI was isolated from respiratory secretions prior to the SSI in 4/9 patients with microbiologically documented intracerebral SSIs. Patients with SSIs had longer hospital stay, poorer functional capacity on discharge, and higher 90-day mortality. We raise the possibility of post-operative infection acquisition through external CSF devices. Standard operating procedures for their maintenance are necessary.

Obstructive hydrocephalus secondary to odontoid pannus: case report and review of literature.

PubMed

Soon, Wai Cheong; Thanabalasundaram, Gopiga; Thant, Kyaw Zayar; Ogbonnaya, Ebere Sunny; Harrisson, Stuart Edward

2018-04-01

Odontoid pannus or periodontoid pseudotumour is associated with a variety of rheumatological conditions. We report a case of an 80-year old man who presented with acute hydrocephalus following an emergency operation to amputate his infected left big toe. Imaging revealed a large tissue mass causing severe compression at the cervico-medullary junction and obstruction of CSF flow. The acute hydrocephalus was presumed to be related to neck manoeuvring during general anaesthesia. Following an initial emergency CSF diversion through external ventricular drainage catheter insertion, the patient subsequently underwent ventriculo-peritoneal insertion and posterior spinal decompression and fixation. To our knowledge, there have been no reported cases of tophaceous gout of the odontoid pannus causing acute hydrocephalus.

Future Prospects for the Total Artificial Heart.

PubMed

Sunagawa, Gengo; Horvath, David J; Karimov, Jamshid H; Moazami, Nader; Fukamachi, Kiyotaka

2016-01-01

A total artificial heart (TAH) is the sole remaining option for patients with biventricular failure who cannot be rescued by left ventricular assist devices (LVADs) alone. However, the pulsatile TAH in clinical use today has limitations: large pump size, unknown durability, required complex anticoagulation regimen, and association with significant postsurgical complications. That pump is noisy; its large pneumatic driving lines traverse the body, with bulky external components for its drivers. Continuous-flow pumps, which caused a paradigm shift in the LVAD field, have already contributed to the rapidly evolving development of TAHs. Novel continuous-flow TAHs are only in preclinical testing or developmental stages. We here review the current state of TAHs, with recommended requirements for the TAH of the future.

Prognostic impact of isolated right ventricular dysfunction in sepsis and septic shock: an 8-year historical cohort study.

PubMed

Vallabhajosyula, Saraschandra; Kumar, Mukesh; Pandompatam, Govind; Sakhuja, Ankit; Kashyap, Rahul; Kashani, Kianoush; Gajic, Ognjen; Geske, Jeffrey B; Jentzer, Jacob C

2017-09-07

Echocardiographic myocardial dysfunction is reported commonly in sepsis and septic shock, but there are limited data on sepsis-related right ventricular dysfunction. This study sought to evaluate the association of right ventricular dysfunction with clinical outcomes in patients with severe sepsis and septic shock. Historical cohort study of adult patients admitted to all intensive care units at the Mayo Clinic from January 1, 2007 through December 31, 2014 for severe sepsis and septic shock, who had an echocardiogram performed within 72 h of admission. Patients with prior heart failure, cor-pulmonale, pulmonary hypertension and valvular disease were excluded. Right ventricular dysfunction was defined by the American Society of Echocardiography criteria. Outcomes included 1-year survival, in-hospital mortality and length of stay. Right ventricular dysfunction was present in 214 (55%) of 388 patients who met the inclusion criteria-isolated right ventricular dysfunction was seen in 100 (47%) and combined right and left ventricular dysfunction in 114 (53%). The baseline characteristics were similar between cohorts except for the higher mechanical ventilation use in patients with isolated right ventricular dysfunction. Echocardiographic findings demonstrated lower right ventricular and tricuspid valve velocities in patients with right ventricular dysfunction and lower left ventricular ejection fraction and increased mitral E/e' ratios in patients with combined right and left ventricular dysfunction. After adjustment for age, comorbidity, illness severity, septic shock and use of mechanical ventilation, isolated right ventricular dysfunction was independently associated with worse 1-year survival-hazard ratio 1.6 [95% confidence interval 1.2-2.1; p = 0.002) in patients with sepsis and septic shock. Isolated right ventricular dysfunction is seen commonly in sepsis and septic shock and is associated with worse long-term survival.

Ventricular Arrhythmias in the North American Multidisciplinary Study of ARVC

PubMed Central

Link, Mark S.; Laidlaw, Douglas; Polonsky, Bronislava; Zareba, Wojciech; McNitt, Scott; Gear, Kathleen; Marcus, Frank; Mark Estes, NA

2015-01-01

BACKGROUND Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with sudden cardiac death. However, the selection of patients for implanted cardioverter-defibrillators (ICDs), as well as programming of the ICD, is unclear. OBJECTIVES The objective of this study was to identify predictors, characteristics, and treatment of ventricular arrhythmias in patients with ARVC. METHODS The Multidisciplinary Study of Right Ventricular Cardiomyopathy established the North American ARVC Registry and enrolled patients with a diagnosis of ARVC. Patients were followed prospectively. RESULTS Of 137 patients enrolled, 108 received ICDs. Forty-eight patients had 502 sustained episodes of ventricular arrhythmias, including 489 that were monomorphic and 13 that were polymorphic. In the patients with ICDs, independent predictors of ventricular arrhythmias in follow-up included spontaneous sustained ventricular arrhythmias before ICD implantation and T-wave inversions inferiorly. The only independent predictor for life-threatening arrhythmias, defined as sustained ventricular tachycardia (VT) ≥240 beats/min or ventricular fibrillation, was a younger age at enrollment. Anti-tachycardia pacing (ATP), independent of the cycle length of the VT, was successful in terminating 92% of VT episodes. CONCLUSIONS In the North American ARVC Registry, the majority of ventricular arrhythmias in follow-up are monomorphic. Risk factors for ventricular arrhythmias were spontaneous ventricular arrhythmias before enrollment and a younger age at ICD implantation. ATP is highly successful in terminating VT, and all ICDs should be programmed for ATP, even for rapid VT. PMID:25011714

Proposal for a new classification of variations in the iliac venous system based on internal iliac veins: a case series and a review of double and left inferior vena cava.

PubMed

Hayashi, Shogo; Naito, Munekazu; Hirai, Shuichi; Terayama, Hayato; Miyaki, Takayoshi; Itoh, Masahiro; Fukuzawa, Yoshitaka; Nakano, Takashi

2013-09-01

There are many reports on variations in the inferior vena cava (IVC), particularly double IVC (DIVC) and left IVC (LIVC). However, no systematic report has recorded iliac vein (IV) flow patterns in the DIVC and LIVC. In this study, we examined IV flow patterns in both DIVC and LIVC observed during gross anatomy courses conducted for medical students and in previously reported cases. During the gross anatomy courses, three cases of DIVC and one case of LIVC were found in 618 cadavers. The IV flow pattern from these four cases and all other previously reported cases can be classified into one of the following three types according to the vein into which the internal iliac vein drained: the ipsilateral external IV; confluence of the ipsilateral external IV and IVC; and the communicating vein, which connects the IVC and the contralateral IVC or its iliac branch. This classification, which is based on the internal IV course, is considered to be useful because IV variations have the potential to cause clinical problems during related retroperitoneal surgery, venous interventional radiology, and diagnostic procedures for pelvic cancer.

Trauma pancreaticoduodenectomy for complex pancreaticoduodenal injury. Delayed reconstruction.

PubMed

Gupta, Vikas; Wig, Jai Dev; Garg, Harsh

2008-09-02

To assess the feasibility and safety of the delayed reconstruction approach in patients with complex pancreaticoduodenal injuries. Tertiary care center in Northern India. Five patients with complex pancreaticoduodenal injuries, three following blunt and two following penetrating injury. All patients underwent a pancreaticoduodenectomy. T-tube drainage of the common bile duct and external tube drainage of the pancreatic duct were established. A wide bore tube drain was left in the right upper abdomen. The postoperative course was uneventful in four patients. One patient died from coagulopathy on the 4th postoperative day. Delayed reconstruction was carried out in four patients. In one patient, a pancreaticojejunal anastomosis could not be performed. The postoperative period was uneventful and no patient had a biliary or a pancreatic leak. All four patients are well on follow-up. Delayed reconstruction in complex pancreaticoduodenal injuries is a feasible and viable option as was demonstrated by this study. Controlled external tube drainage of the bile and pancreatic ducts facilitates postoperative care and prevents on-going contamination of the peritoneal cavity with bile and pancreatic juice. Leaving behind the uncinate process shortens the operating time with less blood loss. Planned reconstruction is carried out once the inflammatory process has settled.

Liquid oxygen sloshing in Space Shuttle External Tank

NASA Technical Reports Server (NTRS)

Kannapel, M. D.; Przekwas, A. J.; Singhal, A. K.; Costes, N. C.

1987-01-01

This paper describes a numerical simulation of the hydrodynamics within the liquid oxygen tank of the Space Shuttle External Tank during liftoff. Before liftoff, the tank is filled with liquid oxygen (LOX) to approximately 97 percent with the other 3 percent containing gaseous oxygen (GOX) and helium. During liftoff, LOX is drained from the bottom of the tank, and GOX is pumped into the tank's ullage volume. There is a delay of several seconds before the GOX reaches the tank which causes the ullage pressure to decrease for several seconds after liftoff; this pressure 'slump' is a common phenomenon in rocket propulsion. When four slosh baffles were removed from the tank, the ullage gas pressure dropped more rapidly than in all previous flights. The purpose of this analysis was to determine whether the removal of the baffles could have caused the increased pressure 'slump' by changing the LOX surface dynamics. The results show that the LOX surface undergoes very high vertical accelerations (up to 5 g) and, therefore, splashing almost certainly occurs. The number of baffles does not affect the surface if the structural motion is assumed; but, the number of baffles may affect the structural motion of the tank.

KSC-2010-5946

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5941

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5942

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

KSC-2010-5944

NASA Image and Video Library

2010-12-22

CAPE CANAVERAL, Fla. -- Preparations are under way in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida to examine space shuttle Discovery's external fuel tank. Technicians will begin to remove thermal sensors that will give engineers data about the changes the tank went through during the loading and draining of super-cold propellants during a tanking test on Dec. 17. Engineers also will examine 21-foot-long support beams, called stringers, on the outside of the tank's intertank region. Also on the agenda, is to re-apply foam to the outside of the tank. Discovery's next launch opportunity to the International Space Station on the STS-133 mission is no earlier than Feb. 3, 2011. For more information on STS-133, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/. Photo credit: NASA/Dimitri Gerondidakis

[Anatomy of the pelvic lymphatic system].

PubMed

Wolfram-Gabel, R

2013-10-01

The lymphatic system of the pelvis collects the lymph of the genital and urinary organs and of the digestive tract. It is formed by lymphatic nodes and vessels situated inside the conjunctive tissue, near the organs (visceral lymphatic nodes) but especially along the external, internal and common iliac vessels (iliac lymphatic nodes). These nodes receive afferent vessels issued from the different pelvic organs. From the iliac lymphnodes arise efferent vessels running towards lymphatic collectors, situated above them, and which end in the lymphatic lombar duct. The lymphatic pathways represent the preferential way of scattering of cancerous cells. Therefore, the knowledge of the anatomy, of the situation and of the draining of the nodes is of the utmost importance in the evaluation of a cancer of a pelvic organ. Copyright © 2013. Published by Elsevier SAS.

Echocardiographic left ventricular masses in distance runners and weight lifters

NASA Technical Reports Server (NTRS)

Longhurst, J. C.; Gonyea, W. J.; Mitchell, J. H.; Kelly, A. R.

1980-01-01

The relationships of different forms of exercise training to left ventricular mass and body mass are investigated by echocardiographic studies of weight lifters, long-distance runners, and comparatively sized untrained control subjects. Left ventricular mass determinations by the Penn convention reveal increased absolute left ventricular masses in long-distance runners and competitive weight lifters with respect to controls matched for age, body weight, and body surface area, and a significant correlation between ventricular mass and lean body mass. When normalized to lean body mass, the ventricular masses of distance runners are found to be significantly higher than those of the other groups, suggesting that dynamic training elevates left ventricular mass compared to static training and no training, while static training increases ventricular mass only to the extent that lean body mass is increased.

Remote magnetic navigation to map and ablate left coronary cusp ventricular tachycardia.

PubMed

Burkhardt, J David; Saliba, Walid I; Schweikert, Robert A; Cummings, Jennifer; Natale, Andrea

2006-10-01

Premature ventricular contractions (PVCs) and ventricular tachycardia may arise from the coronary cusps. Navigation, mapping, and ablation in the coronary cusps can be challenging. Remote magnetic navigation may offer an alternative to conventional manually operated catheters. We report a case of left coronary cusp ventricular tachycardia ablation using remote magnetic navigation. Right ventricular outflow tract and coronary cusp mapping, and ablation of the left coronary cusp using a remote magnetic navigation and three-dimensional (3-D) mapping system was performed in a 28-year-old male with frequent, symptomatic PVCs and ventricular tachycardia. Successful ablation of left coronary cusp ventricular tachycardia was performed using remote magnetic navigation. Remote magnetic navigation may be used to map and ablate PVCs and ventricular tachycardia originating from the coronary cusps.

Improved long-term survival with subdural drains following evacuation of chronic subdural haematoma.

PubMed

Guilfoyle, Mathew R; Hutchinson, Peter J A; Santarius, Thomas

2017-05-01

Chronic subdural haematoma (CSDH) is a common condition that is effectively managed by burrhole drainage but requires repeat surgery in a significant minority of patients. The Cambridge Chronic Subdural Haematoma Trial (CCSHT) was a randomised controlled study that showed placement of subdural drains for 48 h following burrhole evacuation significantly reduces the incidence of reoperation and improves survival at 6 months. The present study examined the long-term survival of the patients in the trial. In the original trial patients at a single neurosurgical centre from 2004-2007 were randomly assigned to receive a drain (n = 108) or no drain (n = 107) following burrhole drainage of CSDH. We ascertained whether the trial patients were alive in February 2016-a minimum of 8 years following enrollment-via the UK NHS tracing service. Survival was compared between the trial groups and against expected survival for the UK general population matched for age and sex. At 5 years following surgery the drain group continued to have significantly better survival than the no drain patients (p = 0.027), but this was no longer apparent at 10 years. Survival of patients in the drain group did not differ significantly from that of the general population whereas patients who did not receive a drain had significantly lower survival than expected (p = 0.0006). Subdural drains following CSDH evacuation are associated with improved long-term survival, which appears similar to that expected for the general population of the same age and sex. All patients having burrhole CSDH evacuation should receive a drain as standard practice unless specifically contraindicated.

Arrhythmogenic Right Ventricular Cardiomyopathy in an Endurance Athlete Presenting with Ventricular Tachycardia and Normal Right Ventricular Function.

PubMed

Hedley, Jeffrey S; Al Mheid, Ibhar; Alikhani, Zoubin; Pernetz, Maria A; Kim, Jonathan H

2017-08-01

Arrhythmogenic right ventricular cardiomyopathy, a genetically inherited disease that results in fibrofatty replacement of normal cardiac myocytes, has been associated with sudden cardiac death in athletes. Long-term participation in endurance exercise hastens the development of both the arrhythmic and structural arrhythmogenic right ventricular cardiomyopathy phenotypes. We describe the unusual case of a 34-year-old, symptomatic, female endurance athlete who had arrhythmogenic right ventricular cardiomyopathy in the presence of a structurally normal right ventricle. Clinicians should be aware of this infrequent presentation when evaluating athletic patients who have ventricular arrhythmias and normal findings on cardiac imaging studies.

Significance of postshunt ventricular asymmetries.

PubMed

Linder, M; Diehl, J T; Sklar, F H

1981-08-01

Ventricular asymmetries after shunt surgery were studied. Right and left ventricular areas from pre-and postoperative computerized tomography scans were measured with a computer digitizing technique, and the respective areas were expressed as a ratio. Measurements were made from the scans of 15 hydrocephalic children selected at random. Ages at surgery ranged from 1 to 101 weeks. The results indicate a significantly greater decrease in ventricular size on the side of the ventricular shunt catheter. Multiple regression analysis showed no relationship between the magnitude of change in ventricular size and either the patients' age orn the time intervals between surgery and follow-up scans. Possible mechanisms for these postshunt ventricular asymmetries are discussed.

A novel method for electronic measurement and recording of surgical drain output.

PubMed

van Duren, Bernard Hendrik; van Boxel, Gijsbert Isaac

2017-04-01

Surgical drains are used to collect and measure fluids (e.g. serous fluid, lymph, blood, etc.). The volume of fluid in the container is measured using graded markings on the container and then recorded manually on a "drain chart" allowing for manual rate calculations. This method is dependant on regularly checking the volume of the drain and recording the value accurately; unfortunately, this is often not feasible due to staffing levels and time constraints. This results in inaccurate "drain charts" making clinical decisions based on these figures unreliable. Often the lack of confidence in these measurements leads to delayed drain removal with consequent increased infection risks and potential delayed discharge. Accurate digital measurement of drain content would have a significant impact on clinical care. This paper describes a digital technology to measure volume, making use of a positive terminal at the lowest point of the vessel and negative (sensor) terminals placed at accurate intervals along an axis of the vessel. A proof-of-concept prototype was developed using commercially available electronic components to test the feasibility of a technology for electronic measurement and recording of surgical drain content. In a simulated environment, the proposed technology was shown to be effective and accurate. The proposed electronic drain has a number of advantages over currently used devices in saving time and easing pressure on nursing staff, reduce disturbance of patients, and allows for preset alarms.

Short-Channel Tunneling Field-Effect Transistor with Drain-Overlap and Dual-Metal Gate Structure for Low-Power and High-Speed Operations.

PubMed

Yoon, Young Jun; Eun, Hye Rim; Seo, Jae Hwa; Kang, Hee-Sung; Lee, Seong Min; Lee, Jeongmin; Cho, Seongjae; Tae, Heung-Sik; Lee, Jung-Hee; Kang, In Man

2015-10-01

We have investigated and proposed a highly scaled tunneling field-effect transistor (TFET) based on Ge/GaAs heterojunction with a drain overlap to suppress drain-induced barrier thinning (DIBT) and improve low-power (LP) performance. The highly scaled TFET with a drain overlap achieves lower leakage tunneling current because of the decrease in tunneling events between the source and drain, whereas a typical short-channel TFET suffers from a great deal of tunneling leakage current due to the DIBT at the off-state. However, the drain overlap inevitably increases the gate-to-drain capacitance (Cgd) because of the increase in the overlap capacitance (Cov) and inversion capacitance (Cinv). Thus, in this work, a dual-metal gate structure is additionally applied along with the drain overlap. The current performance and the total gate capacitance (Cgg) of the device with a dual-metal gate can be possibly controlled by adjusting the metal gate workfunction (φgate) and φoverlap-gate in the overlapping regions. As a result, the intrinsic delay time (τ) is greatly reduced by obtaining lower Cgg divided by the on-state current (Ion), i.e., Cgg/Ion. We have successfully demonstrated excellent LP and high-speed performance of a highly scaled TFET by adopting both drain overlap and dual-metal gate with DIBT minimization.

Water table dynamics in undisturbed, drained and restored blanket peat

NASA Astrophysics Data System (ADS)

Holden, J.; Wallage, Z. E.; Lane, S. N.; McDonald, A. T.

2011-05-01

SummaryPeatland water table depth is an important control on runoff production, plant growth and carbon cycling. Many peatlands have been drained but are now subject to activities that might lead to their restoration including the damming of artificial drains. This paper investigates water table dynamics on intact, drained and restored peatland slopes in a blanket peat in northern England using transects of automated water table recorders. Long-term (18 month), seasonal and short-term (storm event) records are explored. The restored site had drains blocked 6 years prior to monitoring commencing. The spatially-weighted mean water table depths over an 18 month period were -5.8 cm, -8.9 cm and -11.5 cm at the intact, restored and drained sites respectively. Most components of water table behaviour at the restored site, including depth exceedance probability curves, seasonality of water table variability, and water table responses to individual rainfall events were intermediate between that of the drained and intact sites. Responses also depended on location with respect to the drains. The results show that restoration of drained blanket peat is difficult and the water table dynamics may not function in the same way as those in undisturbed blanket peat even many years after management intervention. Further measurement of hydrological processes and water table responses to peatland restoration are required to inform land managers of the hydrological success of those projects.

Nurses’ knowledge of care of chest drain: A survey in a Nigerian semiurban university hospital

PubMed Central

Kesieme, Emeka Blessius; Essu, Ifeanyichukwu Stanley; Arekhandia, Bruno Jeneru; Welcker, Katrin; Prisadov, Georgi

2016-01-01

Background/Objective: Inefficient nursing care of chest drains may associated with unacceptable and sometimes life-threatening complications. This report aims to ascertain the level of knowledge of care of chest drains among nurses working in wards in a teaching hospital in Nigeria. Methods: A cross-sectional study among nurses at teaching hospital using pretested self-administered questionnaires. Results: The majority were respondents aged between 31 and 40 years (45.4%) and those who have nursing experience between 6 and 10 years. Only 37 respondents (26.2%) had a good knowledge of nursing care of chest drains. Knowledge was relatively higher among nurses who cared for chest drains daily, nurses who have a work experience of <10 years, low-rank nurses and those working in the female medical ward; however, the relationship cant (P > 0.05). Performance was poor on the questions on position of drainage system were not statistically significant with relationship to waist level while mobilizing the patient, application of suction to chest drains, daily changing of dressing over chest drain insertion site, milking of tubes and drainage system with dependent loop. Conclusion: The knowledge of care of chest drains among nurses is poor, especially in the key post procedural care. There is an urgent need to train them so as to improve the nursing care of patients managed with chest drains. PMID:26857934

Right ventricular pressure response to exercise in adults with isolated ventricular septal defect closed in early childhood.

PubMed

Moller, Thomas; Lindberg, Harald; Lund, May Brit; Holmstrom, Henrik; Dohlen, Gaute; Thaulow, Erik

2018-06-01

We previously demonstrated an abnormally high right ventricular systolic pressure response to exercise in 50% of adolescents operated on for isolated ventricular septal defect. The present study investigated the prevalence of abnormal right ventricular systolic pressure response in 20 adult (age 30-45 years) patients who underwent surgery for early ventricular septal defect closure and its association with impaired ventricular function, pulmonary function, or exercise capacity. The patients underwent cardiopulmonary tests, including exercise stress echocardiography. Five of 19 patients (26%) presented an abnormal right ventricular systolic pressure response to exercise ⩾ 52 mmHg. Right ventricular systolic function was mixed, with normal tricuspid annular plane systolic excursion and fractional area change, but abnormal tricuspid annular systolic motion velocity (median 6.7 cm/second) and isovolumetric acceleration (median 0.8 m/second2). Left ventricular systolic and diastolic function was normal at rest as measured by the peak systolic velocity of the lateral wall and isovolumic acceleration, early diastolic velocity, and ratio of early diastolic flow to tissue velocity, except for ejection fraction (median 53%). The myocardial performance index was abnormal for both the left and right ventricle. Peak oxygen uptake was normal (mean z score -0.4, 95% CI -2.8-0.3). There was no association between an abnormal right ventricular systolic pressure response during exercise and right or left ventricular function, pulmonary function, or exercise capacity. Abnormal right ventricular pressure response is not more frequent in adult patients compared with adolescents. This does not support the theory of progressive pulmonary vascular disease following closure of left-to-right shunts.

Growth and Seed Production of Sawtooth Oak (Quercus acutissima) 22 Years After Direct Seeding

Treesearch

J.C.G. Goelz; D.W. Carlson

1997-01-01

Sawtooth oak (Quercus acutissima Carruth.) was direct seeded at two locations, one with a poorly drained clay soil and the other with a well-drained silty clay loam. For comparison, Nuttall oak (Q. nuttallii Palmer) was direct seeded on the poorly drained clay soil. On the well-drained silty clay loam, sawtooth oak was 18 ft...

[Ventricular tachycardia in a patient with rate-responsive cardiac pacemaker].

PubMed

Himbert, C; Lascault, G; Tonet, J; Coutte, R; Busquet, P; Frank, R; Grosgogeat, Y

1992-11-01

The authors report a case of syncopal ventricular tachycardia in a patient with a respiratory-dependent rate responsive pacemaker, followed-up for valvular heart disease with severe left ventricular dysfunction and sustained atrial and ventricular arrhythmias. The introduction of low dose betablocker therapy with reinforcement of the treatment of cardiac failure controlled the ventricular arrhythmia, after suppression of the data responsive function had been shown to be ineffective. The authors discuss the role of the rate responsive function in the triggering of the ventricular tachycardias.

Interaction of the Bored Sand and Gravel Drain Pile with the Surrounding Compacted Loam Soil and Foundation Raft Taking into Account Rheological Properties of the Loam Soil and Non-Linear Properties of the Drain Pile

NASA Astrophysics Data System (ADS)

Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Anzhelo, G. O.; Buslov, A. S.

2018-01-01

The task of the interaction of the sand and gravel drain pile with the surrounding loam soil after its preliminary deep compaction and formation of the composite ground cylinder from the drain pile and surrounding compacted loam soil (cells) is considered in the article. It is seen that the subsidence and carrying capacity of such cell considerably depends on physical and mechanical properties of the compacted drain piles and surrounding loam soil as well as their diameter and intercellular distance. The strain-stress state of the cell is considered not taking into account its component elements, but taking into account linear and elastic-plastic properties of the drain pile and creep flow of the surrounding loam soil. It is stated that depending on these properties the distribution and redistribution of the load on a cell takes place from the foundation raft between the drain pile and surrounding soil. Based on the results of task solving the formulas and charts are given demonstrating the ratio of the load between the drain pile and surrounding loam soil in time.

Si1-yGey or Ge1-zSnz Source/Drain Stressors on Strained Si1-xGex-Channel P-Type Field-Effect Transistors: A Technology Computer-Aided Design Study

NASA Astrophysics Data System (ADS)

Eneman, Geert; De Keersgieter, An; Witters, Liesbeth; Mitard, Jerome; Vincent, Benjamin; Hikavyy, Andriy; Loo, Roger; Horiguchi, Naoto; Collaert, Nadine; Thean, Aaron

2013-04-01

The interaction between two stress techniques, strain-relaxed buffers (SRBs) and epitaxial source/drain stressors, is studied on short, Si1-xGex- and Ge-channel planar transistors. This work focuses on the longitudinal channel stress generated by these two techniques. Unlike for unstrained silicon-channel transistors, for strained channels on top of a strain-relaxed buffer a source/drain stressor without recess generates similar longitudinal channel stress than source/drain stressors with a deep recess. The least efficient stress transfer is obtained for source/drain stressors with a small recess that removes only the strained channel, not the substrate underneath. These trends are explained by a trade-off between elastic relaxation of the strained-channel during source/drain recess and the increased stress generation of thicker source/drain stressors. For Ge-channel pFETs, GeSn source/drains and Si1-xGex strain-relaxed buffers are efficient stressors for mobility enhancement. The former is more efficient for gate-last schemes than for gate-first, while the stress generated by the SRB is found to be independent of the gate-scheme.

Studies on deflection area vectors of QRS and T and ventricular gradient in right ventricular hypertrophy.

PubMed

Kawaguchi, Y

1985-04-01

QRS deflection area vector (Aqrs), T deflection area vector (At) and ventricular gradient (G) in right ventricular hypertrophy were studied in 53 subjects divided on the basis of cardiac catheterization data into four subgroups; normal controls, mild MS group, right ventricular pressure overload group and right ventricular volume overload group. Aqrs, At and G of the four subgroups were calculated using a microcomputer and compared. Aqrs in right ventricular pressure overload group and volume overload group was shifted to the right and slightly anteriorly from that in normal control group. At in right ventricular pressure overload group and volume overload group was shifted slightly upwards and significantly posteriorly from that in the normal control and mild MS groups. G in right ventricular pressure overload group and volume overload group was shifted to the right and significantly posteriorly from that in normal control and mild MS groups. Using multivariative analysis, we developed criteria for diagnosing right ventricular hypertrophy with At: 0.059At(Z) - 0.0145 [At] - 0.2608 less than or equal to 0. Application of this criteria achieved 82.4% (28 of 34) sensitivity in the patients with right ventricular hypertrophy and 90.9% (10 of 11) specificity in the normal control subjects.

Enhanced performance of amorphous In-Ga-Zn-O thin-film transistors using different metals for source/drain electrodes

NASA Astrophysics Data System (ADS)

Pyo, Ju-Young; Cho, Won-Ju

2017-09-01

In this paper, we propose an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) with off-planed source/drain electrodes. We applied different metals for the source/drain electrodes with Ni and Ti to control the work function as high and low. When we measured the configuration of Ni to drain and source to Ti, the a-IGZO TFT showed increased driving current, decreased leakage current, a high on/off current ratio, low subthreshold swing, and high mobility. In addition, we conducted a reliability test with a gate bias stress test at various temperatures. The results of the reliability test showed the Ni drain and Ti drain had an equivalent effective energy barrier height. Thus, we confirmed that the proposed off-planed structure improved the electrical characteristics of the fabricated devices without any degradation of characteristics. Through the a-IGZO TFT with different source/drain electrode metal engineering, we realized high-performance TFTs for next-generation display devices.

Necessity of suction drains in gynecomastia surgery.

PubMed

Keskin, Mustafa; Sutcu, Mustafa; Cigsar, Bulent; Karacaoglan, Naci

2014-05-01

The aim of gynecomastia surgery is to restore a normal chest contour with minimal signs of breast surgery. The authors examine the rate of complications in gynecomastia surgery when no closed-suction drains are placed. One hundred thirty-eight consecutive male patients who underwent gynecomastia surgery without drains were retrospectively analyzed to determine whether the absence of drains adversely affected patient outcomes. Patients were managed by ultrasonic-assisted liposuction both with and without the pull-through technique. The mean age of the patients was 29 years, and the mean volume of breast tissue aspirated was 350 mL per beast. Pull-through was needed in 23 cases. There was only 1 postoperative hematoma. These results are comparable with previously published data for gynecomastia surgery in which drains were placed, suggesting that the absence of drains does not adversely affect postoperative recovery. Routine closed-suction drainage after gynecomastia surgery is unnecessary, and it may be appropriate to omit drains after gynecomastia surgery.

Diastolic heart failure associated with hemangiosarcoma infiltrating left ventricular walls in a dog

PubMed Central

Osuga, Tatsuyuki; Nakamura, Kensuke; Morita, Tomoya; Kagawa, Yumiko; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

2017-01-01

A 9-year-old Shetland sheepdog was diagnosed with cardiogenic pulmonary edema. Echocardiography revealed focally thickened left ventricular free wall and interventricular septum and left atrial dilation. Left ventricular systolic function was preserved. Doppler echocardiography of transmitral flow indicated restrictive left ventricular filling. Cardiac histopathology demonstrated hemangiosarcoma infiltrating the left ventricular walls. PMID:29089652

Diastolic heart failure associated with hemangiosarcoma infiltrating left ventricular walls in a dog.

PubMed

Osuga, Tatsuyuki; Nakamura, Kensuke; Morita, Tomoya; Kagawa, Yumiko; Ohta, Hiroshi; Takiguchi, Mitsuyoshi

2017-11-01

A 9-year-old Shetland sheepdog was diagnosed with cardiogenic pulmonary edema. Echocardiography revealed focally thickened left ventricular free wall and interventricular septum and left atrial dilation. Left ventricular systolic function was preserved. Doppler echocardiography of transmitral flow indicated restrictive left ventricular filling. Cardiac histopathology demonstrated hemangiosarcoma infiltrating the left ventricular walls.

Phase I randomized clinical trial of N-acetylcysteine in combination with an adjuvant probenecid for treatment of severe traumatic brain injury in children.

PubMed

Clark, Robert S B; Empey, Philip E; Bayır, Hülya; Rosario, Bedda L; Poloyac, Samuel M; Kochanek, Patrick M; Nolin, Thomas D; Au, Alicia K; Horvat, Christopher M; Wisniewski, Stephen R; Bell, Michael J

2017-01-01

There are no therapies shown to improve outcome after severe traumatic brain injury (TBI) in humans, a leading cause of morbidity and mortality. We sought to verify brain exposure of the systemically administered antioxidant N-acetylcysteine (NAC) and the synergistic adjuvant probenecid, and identify adverse effects of this drug combination after severe TBI in children. IRB-approved, randomized, double-blind, placebo controlled Phase I study in children 2 to 18 years-of-age admitted to a Pediatric Intensive Care Unit after severe TBI (Glasgow Coma Scale [GCS] score ≤8) requiring an externalized ventricular drain for measurement of intracranial pressure (ICP). Patients were recruited from November 2011-August 2013. Fourteen patients (n = 7/group) were randomly assigned after obtaining informed consent to receive probenecid (25 mg/kg load, then 10 mg/kg/dose q6h×11 doses) and NAC (140 mg/kg load, then 70 mg/kg/dose q4h×17 doses), or placebos via naso/orogastric tube. Serum and CSF samples were drawn pre-bolus and 1-96 h after randomization and drug concentrations were measured via UPLC-MS/MS. Glasgow Outcome Scale (GOS) score was assessed at 3 months. There were no adverse events attributable to drug treatment. One patient in the placebo group was withdrawn due to adverse effects. In the treatment group, NAC concentrations ranged from 16,977.3±2,212.3 to 16,786.1±3,285.3 in serum and from 269.3±113.0 to 467.9±262.7 ng/mL in CSF, at 24 to 72 h post-bolus, respectively; and probenecid concentrations ranged from 75.4.3±10.0 to 52.9±25.8 in serum and 5.4±1.0 to 4.6±2.1 μg/mL in CSF, at 24 to 72 h post-bolus, respectively (mean±SEM). Temperature, mean arterial pressure, ICP, use of ICP-directed therapies, surveillance serum brain injury biomarkers, and GOS at 3 months were not different between groups. Treatment resulted in detectable concentrations of NAC and probenecid in CSF and was not associated with undesirable effects after TBI in children. ClinicalTrials.gov NCT01322009.

Phase I randomized clinical trial of N-acetylcysteine in combination with an adjuvant probenecid for treatment of severe traumatic brain injury in children

PubMed Central

Empey, Philip E.; Bayır, Hülya; Rosario, Bedda L.; Poloyac, Samuel M.; Kochanek, Patrick M.; Nolin, Thomas D.; Au, Alicia K.; Horvat, Christopher M.; Wisniewski, Stephen R.; Bell, Michael J.

2017-01-01

Background There are no therapies shown to improve outcome after severe traumatic brain injury (TBI) in humans, a leading cause of morbidity and mortality. We sought to verify brain exposure of the systemically administered antioxidant N-acetylcysteine (NAC) and the synergistic adjuvant probenecid, and identify adverse effects of this drug combination after severe TBI in children. Methods IRB-approved, randomized, double-blind, placebo controlled Phase I study in children 2 to 18 years-of-age admitted to a Pediatric Intensive Care Unit after severe TBI (Glasgow Coma Scale [GCS] score ≤8) requiring an externalized ventricular drain for measurement of intracranial pressure (ICP). Patients were recruited from November 2011-August 2013. Fourteen patients (n = 7/group) were randomly assigned after obtaining informed consent to receive probenecid (25 mg/kg load, then 10 mg/kg/dose q6h×11 doses) and NAC (140 mg/kg load, then 70 mg/kg/dose q4h×17 doses), or placebos via naso/orogastric tube. Serum and CSF samples were drawn pre-bolus and 1–96 h after randomization and drug concentrations were measured via UPLC-MS/MS. Glasgow Outcome Scale (GOS) score was assessed at 3 months. Results There were no adverse events attributable to drug treatment. One patient in the placebo group was withdrawn due to adverse effects. In the treatment group, NAC concentrations ranged from 16,977.3±2,212.3 to 16,786.1±3,285.3 in serum and from 269.3±113.0 to 467.9±262.7 ng/mL in CSF, at 24 to 72 h post-bolus, respectively; and probenecid concentrations ranged from 75.4.3±10.0 to 52.9±25.8 in serum and 5.4±1.0 to 4.6±2.1 μg/mL in CSF, at 24 to 72 h post-bolus, respectively (mean±SEM). Temperature, mean arterial pressure, ICP, use of ICP-directed therapies, surveillance serum brain injury biomarkers, and GOS at 3 months were not different between groups. Conclusions Treatment resulted in detectable concentrations of NAC and probenecid in CSF and was not associated with undesirable effects after TBI in children. Trial registration ClinicalTrials.gov NCT01322009 PMID:28686657

Hot-Electron-Induced Device Degradation during Gate-Induced Drain Leakage Stress

NASA Astrophysics Data System (ADS)

Kim, Kwang-Soo; Han, Chang-Hoon; Lee, Jun-Ki; Kim, Dong-Soo; Kim, Hyong-Joon; Shin, Joong-Shik; Lee, Hea-Beoum; Choi, Byoung-Deog

2012-11-01

We studied the interface state generation and electron trapping by hot electrons under gate-induced drain leakage (GIDL) stress in p-type metal oxide semiconductor field-effect transistors (P-MOSFETs), which are used as the high-voltage core circuit of flash memory devices. When negative voltage was applied to a drain in the off-state, a GIDL current was generated, but when high voltage was applied to the drain, electrons had a high energy. The hot electrons produced the interface state and electron trapping. As a result, the threshold voltage shifted and the off-state leakage current (trap-assisted drain junction leakage current) increased. On the other hand, electron trapping mitigated the energy band bending near the drain and thus suppressed the GIDL current generation.

Jet-controlled freeze valve for use in a glass melter

DOEpatents

Routt, K.R.

1985-07-29

A drain valve for use in furnace for the melting of thermoplastic material is disclosed. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace.

Effect of an intervention in storm drains to prevent Aedes aegypti reproduction in Salvador, Brazil.

PubMed

Souza, Raquel Lima; Mugabe, Vánio André; Paploski, Igor Adolfo Dexheimer; Rodrigues, Moreno S; Moreira, Patrícia Sousa Dos Santos; Nascimento, Leile Camila Jacob; Roundy, Christopher Michael; Weaver, Scott C; Reis, Mitermayer Galvão; Kitron, Uriel; Ribeiro, Guilherme Sousa

2017-07-11

Aedes aegypti, the principal vector for dengue, chikungunya and Zika viruses, is a synanthropic species that uses stagnant water to complete its reproductive cycle. In urban settings, rainfall water draining structures, such as storm drains, may retain water and serve as a larval development site for Aedes spp. reproduction. Herein, we describe the effect of a community-based intervention on preventing standing water accumulation in storm drains and their consequent infestation by adult and immature Ae. aegypti and other mosquitoes. Between April and May of 2016, local residents association of Salvador, Brazil, after being informed of water accumulation and Ae. aegypti infestation in the storm drains in their area, performed an intervention on 52 storm drains. The intervention consisted of placing concrete at the bottom of the storm drains to elevate their base to the level of the outflow tube, avoiding water accumulation, and placement of a metal mesh covering the outflow tube to avoid its clogging with debris. To determine the impact of the intervention, we compared the frequency at which the 52 storm drains contained water, as well as adult and immature mosquitoes using data from two surveys performed before and two surveys performed after the intervention. During the pre-intervention period, water accumulated in 48 (92.3%) of the storm drains, and immature Ae. aegypti were found in 11 (21.2%) and adults in 10 (19.2%). After the intervention, water accumulated in 5 (9.6%) of the storm drains (P < 0.001), none (0.0%) had immatures (P < 0.001), and 3 (5.8%) contained adults (P = 0.039). The total number of Ae. aegypti immatures collected decreased from 109 to 0 (P < 0.001) and adults decreased from 37 to 8 (P = 0.011) after the intervention. Collection of immature and adult non-Aedes mosquitoes (mainly Culex spp.) in the storm drains also decreased after the intervention. This study exemplifies how a simple intervention targeting storm drains can result in a major reduction of water retention, and, consequently, impact Ae. aegypti larval populations. Larger and multi-center evaluations are needed to confirm the potential of citywide structural modifications of storm drains to reduce Aedes spp. infestation level.

Intra-abdominal drain fracture following pancreatic necrosectomy.

PubMed

Campbell, W; Wallace, W; Gibson, E; McCallion, K

2011-06-01

We describe a rare case of iatrogenic fracture of an intra-abdominal tube drain (Portex Robinson drain, Smiths Medical, Kent, UK) in a 74-year-old man. The fracture occurred at the level of an additionally placed fenestration and was identified on CT scanning prior to retrieval at planned re-laparotomy. This case highlights the potential dangers of modifying pre-formed drains and recommends against this practice.

Coexistence of congenital left ventricular aneurysm and prominent left ventricular trabeculation in a patient with LDB3 mutation: a case report.

PubMed

Shan, Shengshuai; He, Xiaoxiao; He, Lin; Wang, Min; Liu, Chengyun

2017-08-19

The coexistence of congenital left ventricular aneurysm and abnormal cardiac trabeculation with gene mutation has not been reported previously. Here, we report a case of coexisting congenital left ventricular aneurysm and prominent left ventricular trabeculation in a patient with LIM domain binding 3 gene mutation. A 30-year-old Asian man showed paroxysmal sinus tachycardia and Q waves in an electrocardiogram health check. There were no specific findings in physical examinations and serological tests. A coronary-computed tomography angiography check showed normal coronary artery and no coronary stenosis. Both left ventricle contrast echocardiography and cardiac magnetic resonance showed rare patterns of a combination of an apical aneurysm-like out-pouching structure with a wide connection to the left ventricle and prominent left ventricular trabecular meshwork. High-throughput sequencing examinations showed a novel mutation in the LDB3 gene (c.C793>T; p.Arg265Cys). Our finding indicates that the phenotypic expression of two heart conditions, congenital left ventricular aneurysm and prominent left ventricular trabeculation, although rare, can occur simultaneously with LDB3 gene mutation. Congenital left ventricular aneurysm and prominent left ventricular trabeculation may share the same genetic background.

Patterns of left ventricular remodeling among patients with essential and secondary hypertension.

PubMed

Radulescu, Dan; Stoicescu, Laurentiu; Buzdugan, Elena; Donca, Valer

2013-12-01

High blood pressure causes left ventricular hypertrophy, which is a negative prognostic factor among hypertensive patients. To assess left ventricular geometric remodeling patterns in patients with essential hypertension or with hypertension secondary to parenchymal renal disease. We analyzed data from echocardiograms performed in 250 patients with essential hypertension (150 females) and 100 patients with secondary hypertension (60 females). The interventricular septum and the left ventricular posterior wall thickness were measured in the parasternal long-axis. Left ventricular mass was calculated using the Devereaux formula. The most common remodeling type in females and males with essential hypertension were eccentric and concentric left ventricular hypertrophy (cLVH), respectively. Among patients with secondary arterial hypertension, cLVH was most commonly observed in both genders. The prevalence of left ventricular hypertrophy was higher among patients with secondary hypertension. The left ventricular mass index and the relative left ventricular wall thickness were higher in males and also in the secondary hypertension group. Age, blood pressure values and the duration of hypertension, influenced remodeling patterns. We documented a higher prevalence of LVH among patients with secondary hypertension. The type of ventricular remodeling depends on gender, age, type of hypertension, blood pressure values and the duration of hypertension.

Subclinical changes in MRI-determined right ventricular volumes and function in subjects with prediabetes and diabetes.

PubMed

Patscheider, Hannah; Lorbeer, Roberto; Auweter, Sigrid; Schafnitzel, Anina; Bayerl, Christian; Curta, Adrian; Rathmann, Wolfgang; Heier, Margit; Meisinger, Christa; Peters, Annette; Bamberg, Fabian; Hetterich, Holger

2018-07-01

The aim of this study was to assess subclinical changes in right ventricular volumes and function in subjects with prediabetes and diabetes and controls without a history of cardiovascular disease. Data from 400 participants in the KORA FF4 study without self-reported cardiovascular disease who underwent 3-T whole-body MRI were obtained. The right ventricle was evaluated using the short axis and a four-chamber view. Diabetes was defined according to WHO criteria. Associations between glucose tolerance and right ventricular parameters were assessed using multivariable adjusted linear regression models. Data from 337 participants were available for analysis. Of these, 43 (13%) had diabetes, 87 (26%) had prediabetes, and 207 (61%) were normoglycaemic controls. There was a stepwise decrease in right ventricular volumes in men with prediabetes and diabetes in comparison with controls, including right ventricular end-diastolic volume (β = -20.4 and β = -25.6, respectively; p ≤ 0.005), right ventricular end-systolic volume (β = -12.3 and β = -12.7, respectively; p ≤ 0.037) and right ventricular stroke volume (β = -8.1 and β = -13.1, respectively, p ≤ 0.016). We did not observe any association between prediabetes or diabetes and right ventricular volumes in women or between prediabetes or diabetes and right ventricular ejection fraction in men and women. This study points towards early subclinical changes in right ventricular volumes in men with diabetes and prediabetes. • MRI was used to detect subclinical changes in right ventricular parameters. • Diabetes mellitus is associated with right ventricular dysfunction. • Impairment of right ventricular volumes seems to occur predominantly in men.

Radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease.

PubMed

Klein, L S; Shih, H T; Hackett, F K; Zipes, D P; Miles, W M

1992-05-01

Radiofrequency energy has been used safely and successfully to eliminate accessory pathways in patients with the Wolff-Parkinson-White syndrome and the substrate for atrioventricular nodal reentrant tachycardia. However, this form of ablation has had only limited success in eliminating ventricular tachycardia in patients with structural heart disease. In contrast, direct-current catheter ablation has been used successfully to eliminate ventricular tachycardia in patients with and without structural heart disease. The purpose of this study was to test whether radiofrequency energy can safely and effectively ablate ventricular tachycardia in patients without structural heart disease. Sixteen patients (nine women and seven men; mean age, 38 years; range, 18-55 years) without structural heart disease who had ventricular tachycardia underwent radiofrequency catheter ablation to eliminate the ventricular tachycardia. Two patients presented with syncope, nine with presyncope, and five with palpitations only. Mean duration of symptoms was 6.7 years (range, 0.5-20 years). Radiofrequency catheter ablation successfully eliminated ventricular tachycardia in 15 of 16 patients (94%). Sites of ventricular tachycardia origin included the high right ventricular outflow tract (12 patients), the right ventricular septum near the tricuspid valve (three patients), and the left ventricular septum (one patient). The only ablation failure was in a patient whose ventricular tachycardia arose from a region near the His bundle. An accurate pace map, early local endocardial activation, and firm catheter contact with endocardium were associated with successful ablation. Radiofrequency ablation did not cause arrhythmias, produced minimal cardiac enzyme rise, and resulted in no detectable change in cardiac function by Doppler echocardiography. Radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease is effective and safe and may be considered as early therapy in these patients.

Effectiveness of Postoperative Wound Drains in One- and Two-Level Cervical Spine Fusions

PubMed Central

Poorman, Caroline E.; Bianco, Kristina M.; Boniello, Anthony; Yang, Sun; Gerling, Michael C.

2014-01-01

Background Cervical drains have historically been used to avoid postoperative wound and respiratory complications such as excessive edema, hematoma, infection, re-intubation, delayed extubation, or respiratory distress. Recently, some surgeons have ceased using drains because they may prolong hospital stay, operative time, or patient discomfort. The objective of this retrospective case-control series is to investigate the effectiveness of postoperative drains following one- and two-level cervical fusions. Methods A chart review was conducted at a single institution from 2010-2013. Outcome measures included operative time, hospital stay, estimated blood loss and incidence of wound complications (infection, hematoma, edema, and complications with wound healing or evacuation), respiratory complications (delayed extubation, re-intubation, and respiratory treatment), and overall complications (wound complications, respiratory complications, dysphagia, and other complications). Statistical analyses including independent samples t-test, chi-square, analysis of covariance, and linear regression were used to compare patients who received a postoperative drain to those who did not. Results The study population included 39 patients who received a postoperative drain and 42 patients who did not. There were no differences in demographics between the two groups. Patients with drains showed increased operative time (100.1 vs 69.3 min, p < 0.001), hospital stay (38.9 vs. 31.7 hrs, p = 0.021), and blood loss (62.7 vs 29.1 mL, p < 0.001) compared to patients without drains. The frequency of wound complications, respiratory complications, and overall complications did not vary significantly between groups. Conclusions/Level of Evidence Cervical drains may not be necessary for patients undergoing one- and two-level cervical fusion. While there were no differences in incidence of complications between groups, patients treated with drains had significantly longer operative time and length of hospital stay. Clinical relevance This could contribute to excessive costs for patients treated with drains, despite the lack of compelling evidence of the advantages of this treatment in the literature and in the current study. PMID:25694927

Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.

PubMed

Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

2015-03-01

The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantification of non-stormwater flow entries into storm drains using a water balance approach.

PubMed

Xu, Zuxin; Yin, Hailong; Li, Huaizheng

2014-07-15

To make decisions about correcting illicit or inappropriate connections to storm drains, quantification of non-stormwater entries into storm drains was performed using a water flow balance approach, based on data analysis from 2008 to 2011 in a separate storm drainage system in a Shanghai downtown area of 374 ha. The study revealed severe sewage connections to storm drains; meanwhile, misconnections between surface water and storm drains were found to drive frequent non-stormwater pumping discharges at the outfall, producing a much larger volume of outfall flows in a short period. This paper presented a methodology to estimate quantities of inappropriate sewage flow, groundwater infiltration and river water backflow into the storm drains. It was concluded that inappropriate sewage discharge and groundwater seepage into storm drains were approximately 17,860 m(3)/d (i.e., up to 51% of the total sewage flow in the catchment) and 3,624 m(3)/d, respectively, and surface water backflow was up to an average 28,593 m(3)/d. On the basis of this work, end-of-storm pipe interceptor sewers of 0.25 m(3)/s (i.e., 21,600 m(3)/d) would be effective to tackle the problem of sewage connections and groundwater seepage to storm drains. Under this circumstance, the follow-up non-stormwater outfall pumping events indicate misconnections between surface water and storm drains, featuring pumping discharge equivalent to surface water backflow; hence the misconnections should be repaired. The information provided here is helpful in estimating the magnitude of non-stormwater flow entries into storm drains and designing the necessary pollution control activities, as well as combating city floods in storm events. Copyright © 2014. Published by Elsevier B.V.

Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

NASA Astrophysics Data System (ADS)

Rozemeijer, J.; Jansen, S.; de Jonge, H.; Lindblad Vendelboe, A.

2014-12-01

Considering their crucial role in water and solute transport, enhanced monitoring and modeling of agricultural subsurface tube drain systems is important for adequate water quality management. For example, previous work in lowland agricultural catchments has shown that subsurface tube drain effluent contributed up to 80% of the annual discharge and 90-92% of the annual NO3 loads from agricultural fields towards the surface water. However, existing monitoring techniques for flow and contaminant loads from tube drains are expensive and labor-intensive. Therefore, despite the unambiguous relevance of this transport route, tube drain monitoring data are scarce. The presented study aimed developing a cheap, simple, and robust method to monitor loads from tube drains. We are now ready to introduce the Flowcap that can be attached to the outlet of tube drains and is capable of registering total flow, contaminant loads, and flow-averaged concentrations. The Flowcap builds on the existing SorbiCells, a modern passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. By mounting SorbiCells in our Flowcap, a flow-proportional part of the drain effluent is sampled from the main stream. Laboratory testing yielded good linear relations (R-squared of 0.98) between drainage flow rates and sampling rates. The Flowcap was tested in practice for measuring NO3 loads from two agricultural fields and one glasshouse in the Netherlands. The Flowcap registers contaminant loads from tube drains without any need for housing, electricity, or maintenance. This enables large-scale monitoring of non-point contaminant loads via tube drains, which would facilitate the improvement of contaminant transport models and would yield valuable information for the selection and evaluation of mitigation options to improve water quality.

Right and Left Ventricular Function and Mass in Male Elite Master Athletes: A Controlled Contrast-Enhanced Cardiovascular Magnetic Resonance Study.

PubMed

Bohm, Philipp; Schneider, Günther; Linneweber, Lutz; Rentzsch, Axel; Krämer, Nadine; Abdul-Khaliq, Hashim; Kindermann, Wilfried; Meyer, Tim; Scharhag, Jürgen

2016-05-17

It is under debate whether the cumulative effects of intensive endurance exercise induce chronic cardiac damage, mainly involving the right heart. The aim of this study was to examine the cardiac structure and function in long-term elite master endurance athletes with special focus on the right ventricle by contrast-enhanced cardiovascular magnetic resonance. Thirty-three healthy white competitive elite male master endurance athletes (age range, 30-60 years) with a training history of 29±8 years, and 33 white control subjects pair-matched for age, height, and weight underwent cardiopulmonary exercise testing, echocardiography including tissue-Doppler imaging and speckle tracking, and cardiovascular magnetic resonance. Indexed left ventricular mass and right ventricular mass (left ventricular mass/body surface area, 96±13 and 62±10 g/m(2); P<0.001; right ventricular mass/body surface area, 36±7 and 24±5 g/m(2); P<0.001) and indexed left ventricular end-diastolic volume and right ventricular end-diastolic volume (left ventricular end-diastolic volume/body surface area, 104±13 and 69±18 mL/m(2); P<0.001; right ventricular end-diastolic volume/body surface area, 110±22 and 66±16 mL/m(2); P<0.001) were significantly increased in athletes in comparison with control subjects. Right ventricular ejection fraction did not differ between athletes and control subjects (52±8 and 54±6%; P=0.26). Pathological late enhancement was detected in 1 athlete. No correlations were found for left ventricular and right ventricular volumes and ejection fraction with N-terminal pro-brain natriuretic peptide, and high-sensitive troponin was negative in all subjects. Based on our results, chronic right ventricular damage in elite endurance master athletes with lifelong high training volumes seems to be unlikely. Thus, the hypothesis of an exercise-induced arrhythmogenic right ventricular cardiomyopathy has to be questioned. © 2016 American Heart Association, Inc.

Thoracic Epidural Anesthesia Reduces Right Ventricular Systolic Function With Maintained Ventricular-Pulmonary Coupling.

PubMed

Wink, Jeroen; de Wilde, Rob B P; Wouters, Patrick F; van Dorp, Eveline L A; Veering, Bernadette Th; Versteegh, Michel I M; Aarts, Leon P H J; Steendijk, Paul

2016-10-18

Blockade of cardiac sympathetic fibers by thoracic epidural anesthesia may affect right ventricular function and interfere with the coupling between right ventricular function and right ventricular afterload. Our main objectives were to study the effects of thoracic epidural anesthesia on right ventricular function and ventricular-pulmonary coupling. In 10 patients scheduled for lung resection, right ventricular function and its response to increased afterload, induced by temporary, unilateral clamping of the pulmonary artery, was tested before and after induction of thoracic epidural anesthesia using combined pressure-conductance catheters. Thoracic epidural anesthesia resulted in a significant decrease in right ventricular contractility (ΔESV 25 : +25.5 mL, P=0.0003; ΔEes: -0.025 mm Hg/mL, P=0.04). Stroke work, dP/dt MAX , and ejection fraction showed a similar decrease in systolic function (all P<0.05). A concomitant decrease in effective arterial elastance (ΔEa: -0.094 mm Hg/mL, P=0.004) yielded unchanged ventricular-pulmonary coupling. Cardiac output, systemic vascular resistance, and mean arterial blood pressure were unchanged. Clamping of the pulmonary artery significantly increased afterload (ΔEa: +0.226 mm Hg/mL, P<0.001). In response, right ventricular contractility increased (ΔESV 25 : -26.6 mL, P=0.0002; ΔEes: +0.034 mm Hg/mL, P=0.008), but ventricular-pulmonary coupling decreased (Δ(Ees/Ea) = -0.153, P<0.0001). None of the measured indices showed significant interactive effects, indicating that the effects of increased afterload were the same before and after thoracic epidural anesthesia. Thoracic epidural anesthesia impairs right ventricular contractility but does not inhibit the native positive inotropic response of the right ventricle to increased afterload. Right ventricular-pulmonary arterial coupling was decreased with increased afterload but not affected by the induction of thoracic epidural anesthesia. URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2844. Unique identifier: NTR2844. © 2016 American Heart Association, Inc.

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

40 CFR 60.692-2 - Standards: Individual drain systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Emissions From Petroleum Refinery Wastewater Systems § 60.692-2 Standards: Individual drain systems. (a)(1... section. (e) Refinery wastewater routed through new process drains and a new first common downstream...

The fabrication of carbon nanotube field-effect transistors with semiconductors as the source and drain contact materials.

PubMed

Xiao, Z; Camino, F E

2009-04-01

Sb(2)Te(3) and Bi(2)Te(2)Se semiconductor materials were used as the source and drain contact materials in the fabrication of carbon nanotube field-effect transistors (CNTFETs). Ultra-purified single-walled carbon nanotubes (SWCNTs) were ultrasonically dispersed in N-methyl pyrrolidone solvent. Dielectrophoresis was used to deposit and align SWCNTs for fabrication of CNTFETs. The Sb(2)Te(3)- and Bi(2)Te(2)Se-based CNTFETs demonstrate p-type metal-oxide-silicon-like I-V curves with high on/off drain-source current ratio at large drain-source voltages and good saturation of drain-source current with increasing drain-source voltage. The fabrication process developed is novel and has general meaning, and could be used for the fabrication of SWCNT-based integrated devices and systems with semiconductor contact materials.

Cannulation for veno-venous extracorporeal membrane oxygenation

PubMed Central

2018-01-01

Extracorporeal membrane oxygenation (ECMO) is described as a modified, smaller cardiopulmonary bypass circuit. The veno-venous (VV) ECMO circuit drains venous blood, oxygenate the blood, and pump the blood back into the same venous compartment. Draining and reinfusing in the same compartment means there are a risk of recirculation. The draining position within the venous system, ECMO pump flow, return flow position within the venous system and the patients cardiac output (CO) all have an impact on recirculation. Using two single lumen cannulas or one dual lumen cannula, but also the design of the venous cannula, can have an impact on where within the venous system the cannula is draining blood and will affect the efficiency of the ECMO circuit. VV ECMO can be performed with different cannulation strategies. The use of two single lumen cannulas draining in inferior vena cava (IVC) and reinfusing in superior vena cava (SVC) or draining in SVC and reinfusing in IVC, or one dual lumen cannula inserted in right jugular vein is all possible cannulation strategies. Independent of cannulation strategy there will be a risk of recirculation. Efficiency can be reasonable in either strategy if the cannulas are carefully positioned and monitored during the dynamic procedure of pulmonary disease. The disadvantage draining from IVC only occurs when there is a need for converting from VV to veno-arterial (VA) ECMO, reinfusing in the femoral artery. Then draining from SVC is the most efficient strategy, draining low saturated venous blood, and also means low risk of dual circulation. PMID:29732177

Comparison consequences of Jackson-Pratt drain versus chest tube after coronary artery bypass grafting: A randomized controlled clinical trial.

PubMed

Mirmohammad-Sadeghi, Mohsen; Pourazari, Pejman; Akbari, Mojtaba

2017-01-01

Chest tubes are used in every case of coronary artery bypass grafting (CABG) to evacuate shed blood from around the heart and lungs. This study was designed to assess the effective of Jackson-Pratt drain in compare with conventional chest drains after CABG. This was a randomized controlled trial that conducted on 218 patients in Chamran hospital from February to December 2016. Eligible patients were randomized in a 1:1 ratio. Jackson-Pratt drain group had 109 patients who received a chest tube insertion in the pleural space of the left lung and a Jackson-Pratt drain in mediastinum, and Chest tube drainage group had 109 patients who received double chest tube insertion in the pleural space of the left lung and the mediastinum. The incidence of pleural effusions in Jackson-Pratt drain group and chest tube group were not statistically different. The pain score at 2-h in Drain group was significantly higher than chest tube group ( P = 0.001), but the trend of pain score between groups was not significantly different ( P = 0.097). The frequency of tamponade and atrial fibrillation (AF) were significantly lower in Jackson-Pratt drain group ( P < 0.05). The Jackson-Pratt drain is equally effective for preventing cardiac tamponade, pleural effusions, and pain intensity in patients after CABG when compared with conventional chest tubes, but was significantly superior regarding efficacy to hospital and Intensive Care Unit length of stay and the incidence of AF.

[The reasonable use of right ventricular protection strategy in right ventricular outflow tract reconstruction].

PubMed

Zhang, Y; Yuan, H Y; Liu, X B; Wen, S S; Xu, G; Cui, H J; Zhuang, J; Chen, J M

2018-06-01

As a result of right ventricular outflow tract reconstruction, which is the important and basic step of complex cardiac surgery, the blood flow of right ventricular outflow tract is unobstructed, while pulmonary valve regurgitation and right heart dysfunction could be happened. These problems are often ignored in early days, more and more cases of right heart dysfunction need clinical intervention, which is quite difficult and less effective. How to protect effectively the right ventricular function is the focus. At present main methods to protect the right ventricular function include trying to avoid or reduce length of right ventricular incision, reserving or rebuilding the function of the pulmonary valve, using growth potential material for surgery. The protection of the right ventricular function is a systemic project, it involves many aspects, single measures is difficult to provide complete protection, only the comprehensive use of various protection strategy, can help to improve the long-term prognosis.

Left Ventricular Dysfunction and Dilated Cardiomyopathy in Infants and Children with Wolff-Parkinson-White Syndrome in the Absence of Tachyarrhythmias

PubMed Central

2012-01-01

Left ventricular (LV) dysfunction and dilated cardiomyopathy (DCM) are rarely attributable to sustained or incessant tachyarrhythmias in infants and children with Wolff-Parkinson-White (WPW) syndrome. However, several recent reports suggested that significant LV dysfunction may develop in WPW syndrome in the absence of tachyarrhythmias. It is assumed that an asynchronous ventricular activation over the accessory pathway, especially right-sided, induces septal wall motion abnormalities, ventricular remodeling and ventricular dysfunction. The prognosis of DCM associated with asymptomatic WPW is excellent. Loss of ventricular pre-excitation results in mechanical resynchronization and reverse remodeling where LV function recovers completely. The reversible nature of LV dysfunction after loss of ventricular pre-excitation supports the causal relationship between LV dysfunction and ventricular pre-excitation. This review summarizes recent clinical and electrophysiological evidence for development of LV dysfunction or DCM in asymptomatic WPW syndrome, and discusses the underlying pathophysiological mechanism. PMID:23323117

Thyroid-stimulating hormone and adverse left ventricular remodeling following ST-segment elevation myocardial infarction.

PubMed

Reindl, Martin; Feistritzer, Hans-Josef; Reinstadler, Sebastian Johannes; Mueller, Lukas; Tiller, Christina; Brenner, Christoph; Mayr, Agnes; Henninger, Benjamin; Mair, Johannes; Klug, Gert; Metzler, Bernhard

2018-04-01

Adverse left ventricular remodeling is one of the major determinants of heart failure and mortality in patients surviving ST-segment elevation myocardial infarction (STEMI). The hypothalamic-pituitary-thyroid axis is a key cardiovascular regulator; however, the relationship between hypothalamic-pituitary-thyroid status and post-STEMI left ventricular remodeling is unclear. We aimed to investigate the association between thyroid-stimulating hormone concentrations and the development of left ventricular remodeling following reperfused STEMI. In this prospective observational study of 102 consecutive STEMI patients, thyroid-stimulating hormone levels were measured at the first day after infarction and 4 months thereafter. Cardiac magnetic resonance scans were performed within the first week as well as at 4 months follow-up to determine infarct characteristics, myocardial function and as primary endpoint left ventricular remodeling, defined as a 20% or greater increase in left ventricular end-diastolic volume. Patients with left ventricular remodeling ( n=15, 15%) showed significantly lower concentrations of baseline (1.20 [0.92-1.91] vs. 1.73 [1.30-2.60] mU/l; P=0.02) and follow-up (1.11 [0.86-1.28] vs. 1.51 [1.15-2.02] mU/l; P=0.002) thyroid-stimulating hormone. The association between baseline thyroid-stimulating hormone and left ventricular remodeling remained significant after adjustment for major clinical (peak high-sensitivity cardiac troponin T and C-reactive protein, heart rate; odds ratio (OR) 5.33, 95% confidence interval (CI) 1.52-18.63; P=0.01) and cardiac magnetic resonance predictors of left ventricular remodeling (infarct size, microvascular obstruction, ejection fraction; OR 4.59, 95% CI 1.36-15.55; P=0.01). Furthermore, chronic thyroid-stimulating hormone was related to left ventricular remodeling independently of chronic left ventricular remodeling correlates (infarct size, ejection fraction, left ventricular end-diastolic volume, left ventricular end-systolic volume; OR 9.22, 95% CI 1.69-50.22; P=0.01). Baseline and chronic thyroid-stimulating hormone concentrations following STEMI were independently associated with left ventricular remodeling, proposing a novel pathophysiological axis in the development of post-STEMI left ventricular remodeling.

Carbon Dioxide Flux from Rice Paddy Soils in Central China: Effects of Intermittent Flooding and Draining Cycles

PubMed Central

Liu, Yi; Wan, Kai-yuan; Tao, Yong; Li, Zhi-guo; Zhang, Guo-shi; Li, Shuang-lai; Chen, Fang

2013-01-01

A field experiment was conducted to (i) examine the diurnal and seasonal soil carbon dioxide (CO2) fluxes pattern in rice paddy fields in central China and (ii) assess the role of floodwater in controlling the emissions of CO2 from soil and floodwater in intermittently draining rice paddy soil. The soil CO2 flux rates ranged from −0.45 to 8.62 µmol.m−2.s−1 during the rice-growing season. The net effluxes of CO2 from the paddy soil were lower when the paddy was flooded than when it was drained. The CO2 emissions for the drained conditions showed distinct diurnal variation with a maximum efflux observed in the afternoon. When the paddy was flooded, daytime soil CO2 fluxes reversed with a peak negative efflux just after midday. In draining/flooding alternating periods, a sudden pulse-like event of rapidly increasing CO2 efflux occured in response to re-flooding after draining. Correlation analysis showed a negative relation between soil CO2 flux and temperature under flooded conditions, but a positive relation was found under drained conditions. The results showed that draining and flooding cycles play a vital role in controlling CO2 emissions from paddy soils. PMID:23437170

Drain amylase aids detection of anastomotic leak after esophagectomy.

PubMed

Baker, Erin H; Hill, Joshua S; Reames, Mark K; Symanowski, James; Hurley, Susie C; Salo, Jonathan C

2016-04-01

Anastomotic leak following esophagectomy is associated with significant morbidity and mortality. As hospital length of stay decreases, the timely diagnosis of leak becomes more important. We evaluated CT esophagram, white blood count (WBC), and drain amylase levels in the early detection of anastomotic leak. The diagnostic performance of CT esophagram, drain amylase >800 IU/L, and WBC >12,000/µL within the first 10 days after surgery in predicting leak at any time after esophagectomy was calculated. Anastomotic leak occurred in 13 patients (13%). CT esophagram performed within 10 days of surgery diagnosed six of these leaks with a sensitivity of 0.54. Elevation in drain amylase level within 10 days of surgery diagnosed anastomotic leak with a sensitivity of 0.38. When the CT esophagram and drain amylase were combined, the sensitivity rose to 0.69 with a specificity of 0.98. WBC elevation had a sensitivity of 0.92, with a specificity of 0.34. Among 30 patients with normal drain amylase and a normal WBC, one developed an anastomotic leak. Drain amylase adds to the sensitivity of CT esophagram in the early detection of anastomotic leak. Selected patients with normal drain amylase levels and normal WBC may be able to safely forgo CT esophagram.

Placement of percutaneous transhepatic biliary stent using a silicone drain with channels

PubMed Central

Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Mineta, Sho; Mizuguchi, Yoshiaki; Kawano, Yoichi; Sasaki, Junpei; Nakamura, Yoshiharu; Aimoto, Takayuki; Tajiri, Takashi

2009-01-01

This report describes a method for percutaneous transhepatic biliary stenting with a BLAKE Silicone Drain, and discusses the usefulness of placement of the drain connected to a J-VAC Suction Reservoir for the treatment of stenotic hepaticojejunostomy. Percutaneous transhepatic biliary drainage was performed under ultrasonographic guidance in a patient with stenotic hepaticojejunostomy after hepatectomy for hepatic hilum malignancy. The technique used was as follows. After dilatation of the drainage root, an 11-Fr tube with several side holes was passed through the stenosis of the hepaticojejunostomy. A 10-Fr BLAKE Silicone Drain is flexible, which precludes one-step insertion. One week after insertion of the 11-Fr tube, a 0.035-inch guidewire was inserted into the tube. After removal of the 11-Fr tube, the guidewire was put into the channel of a 10-Fr BLAKE Silicone Drain. The drain was inserted into the jejunal limb through the intrahepatic bile duct and was connected to a J-VAC Suction Reservoir. Low-pressure continued suction was applied. Patients can be discharged after insertion of the 10-Fr BLAKE Silicone Drain connected to the J-VAC Suction Reservoir. Placement of a percutaneous transhepatic biliary stent using a 10-Fr BLAKE Silicone Drain connected to a J-VAC Suction Reservoir is useful for the treatment of stenotic hepaticojejunostomy. PMID:19725159

Acute decrease of left ventricular mechanical dyssynchrony and improvement of contractile state and energy efficiency after left ventricular restoration.

PubMed

Schreuder, Jan J; Castiglioni, Alessandro; Maisano, Francesco; Steendijk, Paul; Donelli, Andrea; Baan, Jan; Alfieri, Ottavio

2005-01-01

Surgical left ventricular restoration by means of endoventricular patch aneurysmectomy in patients with postinfarction aneurysm should result in acute improved left ventricular performance by decreasing mechanical dyssynchrony and increasing energy efficiency. Nine patients with left ventricular postinfarction aneurysm were studied intraoperatively before and after ventricular restoration with a conductance volume catheter to analyze pressure-volume relationships, energy efficiency, and mechanical dyssynchrony. The end-systolic elastance was used as a load-independent index of contractile state. Left ventricular energy efficiency was calculated from stroke work and total pressure-volume area. Segmental volume changes perpendicular to the long axis were used to calculate mechanical dyssynchrony. Statistical analysis was performed with the paired t test and least-squares linear regression. Endoventricular patch aneurysmectomy reduced end-diastolic volume by 37% (P < .001), with unchanged stroke volume. Systolic function improved, as derived from increased +dP/dt(max), by 42% (P < .03), peak ejection rate by 28% (P < .02), and ejection fraction by 16% (P < .0002). Early diastolic function improved, as shown by reduction of -dP/dt(max) by 34% (P < .006) and shortened tau by 30% (P < .001). Left ventricular end-systolic elastance increased from 1.2 +/- 0.6 to 2.2 +/- 1 mm Hg/mL (P < .001). Left ventricular energy efficiency increased by 36% (P < .002). Left ventricular mechanical dyssynchrony decreased during systole by 33% (P < .001) and during diastole by 20% (P < .005). Left ventricular restoration induced acute improvements in contractile state, energy efficiency, and relaxation, together with a decrease in left ventricular mechanical dyssynchrony.

Dynamic radionuclide determination of regional left ventricular wall motion using a new digital imaging device

NASA Technical Reports Server (NTRS)

Steele, P.; Kirch, D.

1975-01-01

In 47 men with arteriographically defined coronary artery disease comparative studies of left ventricular ejection fraction and segmental wall motion were made with radionuclide data obtained from the image intensifier camera computer system and with contrast cineventriculography. The radionuclide data was digitized and the images corresponding to left ventricular end-diastole and end-systole were identified from the left ventricular time-activity curve. The left ventricular end-diastolic and end-systolic images were subtracted to form a silhouette difference image which described wall motion of the anterior and inferior left ventricular segments. The image intensifier camera allows manipulation of dynamically acquired radionuclide data because of the high count rate and consequently improved resolution of the left ventricular image.

Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction.

PubMed

Kim, Tae Hoon; Shin, Yu Rim; Kim, Young Sam; Kim, Do Jung; Kim, Hyohyun; Shin, Hong Ju; Htut, Aung Thein; Park, Han Ki

2015-12-01

A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients.

Ventricular fibrillation in an ambulatory patient supported by a left ventricular assist device: highlighting the ICD controversy.

PubMed

Boilson, Barry A; Durham, Lucian A; Park, Soon J

2012-01-01

Left ventricular assist devices (LVADs) provide an effective means of managing advanced pump failure as a means of bridging to cardiac transplantation or as permanent therapy. Although ventricular arrhythmias remain common post-LVAD implantation, such therapy may allow malignant arrhythmias to be tolerated hemodynamically. This report describes the clinical findings in a patient who had likely been in a ventricular tachyarrhythmia for several days and presented in ventricular fibrillation, ambulatory, and mentating normally. This report, with previous similar reports, is additive to the body of evidence that LVADs alter the physiologic impact of ventricular arrhythmias in advanced heart failure and highlights the need for thoughtful programming of implantable cardioverter defibrillator therapies in these patients.

Thoracic Trauma: Which Chest Tube When and Where?

PubMed

Molnar, Tamas F

2017-02-01

Clinical suspicion of hemo/pneumothorax: when in doubt, drain the chest. Stable chest trauma with hemo/pneumothorax: drain and wait. Unstable patient with dislocated trachea must be approached with drain in hand and scalpel ready. Massive hemo/pneumothorax may be controlled by drainage alone. The surgeon should not hesitate to open the chest if too much blood drains over a short period. The chest drainage procedure does not end with the last stitch; the second half of the match is still ahead. The drained patient is in need of physiotherapy and proper pain relief with an extended pleural space: control the suction system. Copyright © 2016 Elsevier Inc. All rights reserved.

Numerical Simulation of Liquids Draining From a Tank Using OpenFOAM

NASA Astrophysics Data System (ADS)

Sakri, Fadhilah Mohd; Sukri Mat Ali, Mohamed; Zaki Shaikh Salim, Sheikh Ahmad; Muhamad, Sallehuddin

2017-08-01

Accurate simulation of liquids draining is a challenging task. It involves two phases flow, i.e. liquid and air. In this study draining a liquid from a cylindrical tank is numerically simulated using OpenFOAM. OpenFOAM is an open source CFD package and it becomes increasingly popular among the academician and also industries. Comparisons with theoretical and results from previous published data confirmed that OpenFOAM is able to simulate the liquids draining very well. This is done using the gas-liquid interface solver available in the standard library of OpenFOAM. Additionally, this study was also able to explain the physics flow of the draining tank.

Cardiac structure and function, and ventricular-arterial interaction 11 years following a pregnancy with preeclampsia.

PubMed

Al-Nashi, Maha; Eriksson, Maria J; Östlund, Eva; Bremme, Katarina; Kahan, Thomas

2016-04-01

Preeclampsia (PE) is associated with acute left ventricular dysfunction. Whether these changes eventually resolve remains unclear. This study assessed left and right ventricular structure and function, and ventricular-arterial interaction in 15 women 11 years after a pregnancy with PE and 16 matched control subjects with a normal pregnancy. We found normal left and right ventricular dimensions, systolic function, and global left ventricular strain, with no differences between the groups. In addition, indices of diastolic function, left and right atrial size, and amino-terminal pro-brain natriuretic peptide were normal and did not differ between the groups. Women with a previous PE had impaired night/day ratios for systolic and diastolic ambulatory blood pressure. However, indices of aortic stiffness or ventricular-arterial coupling did not differ between the groups. In conclusion, we could not demonstrate remaining alterations in systolic or diastolic left or right ventricular function, or in ventricular-arterial interaction in women 11 years after PE. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Clinical determinants and consequences of left ventricular hypertrophy.

PubMed

Messerli, F H

1983-09-26

The left ventricle adapts to an increased afterload such as that produced by arterial hypertension with concentric left ventricular hypertrophy. However, this adaptive process can be modified by a variety of physiologic and pathophysiologic states. Progressive aging, black race, and perhaps disorders with an increased sympathetic outflow seem to accelerate left ventricular hypertrophy. Obesity and other high cardiac output states predominantly produce dilatation of the left ventricle, and their combination with arterial hypertension results in eccentric left ventricular hypertrophy. Similarly, endurance exercise increases left ventricular volume more than wall thickness, whereas isometric exercise produces an increase in wall thickness only. The presence or absence of some physiologic and pathogenetic factors has direct implication on the assessment of what constitutes a "normal" left ventricular structure and function. Left ventricular hypertrophy has been shown to increase ventricular ectopic impulse generation and to put patients at a high risk of sudden death. Moreover, the increase in myocardial mass lowers coronary reserve and enhances cardiac oxygen requirements. Thus, the presence of left ventricular hypertrophy has to be considered as an ominous sign rather than as a benign adaptive process.

Data on Streamflow and Quality of Water and Bottom Sediment in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1998-2000

USGS Publications Warehouse

Paul, Angela P.; Thodal, Carl E.

2003-01-01

This study was initiated to expand upon previous findings that indicated concentrations of dissolved solids, arsenic, boron, mercury, molybdenum, selenium, and uranium were either above geochemical background concentrations or were approaching or exceeding ecological criteria in the lower Humboldt River system. Data were collected from May 1998 to September 2000 to further characterize streamflow and surface-water and bottom-sediment quality in the lower Humboldt River, selected agricultural drains, Upper Humboldt Lake, and Lower Humboldt Drain (ephemeral outflow from Humboldt Sink). During this study, flow in the lower Humboldt River was either at or above average. Flows in Army and Toulon Drains generally were higher than reported in previous investigations. An unnamed agricultural drain contributed a small amount to the flow measured in Army Drain. In general, measured concentrations of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium were higher in water from agricultural drains than in Humboldt River water during this study. Mercury concentrations in water samples collected during the study period typically were below the laboratory reporting level. However, low-level mercury analyses showed that samples collected in August 1999 from Army Drain had higher mercury concentrations than those collected from the river or Toulon Drain or the Lower Humboldt Drain. Ecological criteria and effect concentrations for sodium, chloride, dissolved solids, arsenic, boron, mercury, and molybdenum were exceeded in some water samples collected as part of this study. Although water samples from the agricultural drains typically contained higher concentrations of sodium, chloride, dissolved solids, arsenic, boron, and uranium, greater instantaneous loads of these constituents were carried in the river near Lovelock than in agricultural drains during periods of high flow or non-irrigation. During this study, the high flows in the lower Humboldt River produced the maximum instantaneous loads of sodium, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium at all river-sampling sites, except molybdenum near Imlay. Nevada Division of Environmental Protection monitoring reports on mine-dewatering discharge for permitted releases of treated effluent to the surface waters of the Humboldt River and its tributaries were reviewed for reported discharges and trace-element concentrations from June 1998 to September 1999. These data were compared with similar information for the river near Imlay. In all bottom sediments collected for this study, arsenic concentrations exceeded the Canadian Freshwater Interim Sediment-Quality Guideline for the protection of aquatic life and probable-effect level (concentration). Sediments collected near Imlay, Rye Patch Reservoir, Lovelock, and from Toulon Drain and Army Drain were found to contain cadmium and chromium concentrations that exceeded Canadian criteria. Chromium concentrations in sediments collected from these sites also exceeded the consensus-based threshold-effect concentration. The Canadian criterion for sediment copper concentration was exceeded in sediments collected from the Humboldt River near Lovelock and from Toulon, Army, and the unnamed agricultural drains. Mercury in sediments collected near Imlay and from Toulon Drain in August 1999 exceeded the U.S. Department of the Interior sediment probable-effect level. Nickel concentrations in sediments collected during this study were above the consensus-based threshold-effect concentration. All other river and drain sediments had constituent concentrations below protective criteria and toxicity thresholds. In Upper Humboldt Lake, chloride, dissolved solids, arsenic, boron, molybdenum, and uranium concentrations in surface-water samples collected near the mouth of the Humboldt River generally were higher than in samples collected near the mouth of Army Drain. Ecological criteria or effect con

Closed flume inlet efficiency : [summary].

DOT National Transportation Integrated Search

2014-04-01

The storm drain is an inconspicuous but critical : part of the roadway, especially in Florida. Drains : look deceptively simple, but they must capture : water as efficiently as possible. To help assure : the performance of storm drains, the Florida :...

Statistical variability study of random dopant fluctuation on gate-all-around inversion-mode silicon nanowire field-effect transistors

NASA Astrophysics Data System (ADS)

Yoon, Jun-Sik; Rim, Taiuk; Kim, Jungsik; Kim, Kihyun; Baek, Chang-Ki; Jeong, Yoon-Ha

2015-03-01

Random dopant fluctuation effects of gate-all-around inversion-mode silicon nanowire field-effect transistors (FETs) with different diameters and extension lengths are investigated. The nanowire FETs with smaller diameter and longer extension length reduce average values and variations of subthreshold swing and drain-induced barrier lowering, thus improving short channel immunity. Relative variations of the drain currents increase as the diameter decreases because of decreased current drivability from narrower channel cross-sections. Absolute variations of the drain currents decrease critically as the extension length increases due to decreasing the number of arsenic dopants penetrating into the channel region. To understand variability origins of the drain currents, variations of source/drain series resistance and low-field mobility are investigated. All these two parameters affect the variations of the drain currents concurrently. The nanowire FETs having extension lengths sufficient to prevent dopant penetration into the channel regions and maintaining relatively large cross-sections are suggested to achieve suitable short channel immunity and small variations of the drain currents.