Preoperative spinal cord damage affects the characteristics and prognosis of segmental motor paralysis after cervical decompression surgery.

PubMed

Ikegami, Shota; Tsutsumimoto, Takahiro; Ohta, Hiroshi; Yui, Mutsuki; Kosaku, Hidemi; Uehara, Masashi; Misawa, Hiromichi

2014-03-15

Retrospective analysis. To test the hypothesis that preoperative spinal cord damage affects postoperative segmental motor paralysis (SMP). SMP is an enigmatic complication after cervical decompression surgery. The cause of this complication remains controversial. We particularly focused on preoperative T2-weighted high signal change (T2HSC) on magnetic resonance imaging in the spinal cord, and assessed the influence of preoperative T2HSC on SMP after cervical decompression surgery. A retrospective review of 181 consecutive patients (130 males and 51 females) who underwent cervical decompression surgery was conducted. SMP was defined as development of postoperative motor palsy of the upper extremities by at least 1 grade in manual muscle testing without impairment of the lower extremities. The relationship between the locations of T2HSC in preoperative magnetic resonance imaging and SMP and Japanese Orthopedic Association score was investigated. Preoperative T2HSC was detected in 78% (142/181) of the patients. SMP occurred in 9% (17/181) of the patients. Preoperative T2HSC was not a significant risk factor for the occurrence of SMP (P = 0.682). However, T2HSC significantly influenced the severity of SMP: the number of paralyzed segments increased with an incidence rate ratio of 2.2 (P = 0.026), the manual muscle score deteriorated with an odds ratio of 8.4 (P = 0.032), and the recovery period was extended with a hazard ratio of 4.0 (P = 0.035). In patients with preoperative T2HSC, Japanese Orthopaedic Association scores remained lower than those in patients without T2HSC throughout the entire period including pre- and postoperative periods (P < 0.001). Preoperative T2HSC was associated with worse severity of SMP in patients who underwent cervical decompression surgery, suggesting that preoperative spinal cord damage is one of the pathomechanisms of SMP after cervical decompression surgery. 3.

Degassing of H2O in a phonolitic melt: A closer look at decompression experiments

NASA Astrophysics Data System (ADS)

Marxer, Holger; Bellucci, Philipp; Nowak, Marcus

2015-05-01

Melt degassing during magma ascent is controlled by the decompression rate and can be simulated in decompression experiments. H2O-bearing phonolitic melts were decompressed at a super-liquidus T of 1323 K in an internally heated argon pressure vessel, applying continuous decompression (CD) as well as to date commonly used step-wise decompression (SD) techniques to investigate the effect of decompression method on melt degassing. The hydrous melts were decompressed from 200 MPa at nominal decompression rates of 0.0028-1.7 MPa·s- 1. At final pressure (Pfinal), the samples were quenched rapidly at isobaric conditions with ~ 150 K·s- 1. The bubbles in the quenched samples are often deformed and dented. Flow textures in the glass indicate melt transport at high viscosity. We suggest that this observation is due to bubble shrinkage during quench. This general problem was mostly overlooked in the interpretation of experimentally degassed samples to date. Bubble shrinkage due to decreasing molar volume (Vm) of the exsolved H2O in the bubbles occurs during isobaric rapid quench until the melt is too viscous too relax. The decrease of Vm(H2O) during cooling at Pfinal of the experiments results in a decrease of the bubble volume by a shrinking factor Bs: At nominal decompression rates > 0.17 MPa·s- 1 and a Pfinal of 75 MPa, the decompression method has only minor influence on melt degassing. SD and CD result in high bubble number densities of 104-105 mm- 3. Fast P drop leads to immediate supersaturation with H2O in the melt. At such high nominal decompression rates, the diffusional transport of H2O is limited and therefore bubble nucleation is the predominant degassing process. The residual H2O contents in the melts decompressed to 75 MPa increase with nominal decompression rate. After homogeneous nucleation is triggered, CD rates ≤ 0.024 MPa·s- 1 facilitate continuous reduction of the supersaturation by H2O diffusion into previously nucleated bubbles. Bubble number

Orbital Decompression

MedlinePlus

... A Complications of Sinusitis Epistaxis (Nosebleeds) Allergic Rhinitis (Hay Fever) Headaches and Sinus Disease Disorders of Smell & ... DCR) Disclosure Statement Printer Friendly Orbital Decompression John Lee, MD INTRODUCTION Orbital decompression is a surgical procedure ...

Microvascular Decompression for Classical Trigeminal Neuralgia Caused by Venous Compression: Novel Anatomic Classifications and Surgical Strategy.

PubMed

Wu, Min; Fu, Xianming; Ji, Ying; Ding, Wanhai; Deng, Dali; Wang, Yehan; Jiang, Xiaofeng; Niu, Chaoshi

2018-05-01

Microvascular decompression of the trigeminal nerve is the most effective treatment for trigeminal neuralgia. However, when encountering classical trigeminal neuralgia caused by venous compression, the procedure becomes much more difficult, and failure or recurrence because of incomplete decompression may become frequent. This study aimed to investigate the anatomic variation of the culprit veins and discuss the surgical strategy for different types. We performed a retrospective analysis of 64 consecutive cases in whom veins were considered as responsible vessels alone or combined with other adjacent arteries. The study classified culprit veins according to operative anatomy and designed personalized approaches and decompression management according to different forms of compressive veins. Curative effects were assessed by the Barrow Neurological Institute (BNI) pain intensity score and BNI facial numbness score. The most commonly encountered veins were the superior petrosal venous complex (SPVC), which was artificially divided into 4 types according to both venous tributary distribution and empty point site. We synthetically considered these factors and selected an approach to expose the trigeminal root entry zone, including the suprafloccular transhorizontal fissure approach and infratentorial supracerebellar approach. The methods of decompression consist of interposing and transposing by using Teflon, and sometimes with the aid of medical adhesive. Nerve combing (NC) of the trigeminal root was conducted in situations of extremely difficult neurovascular compression, instead of sacrificing veins. Pain completely disappeared in 51 patients, and the excellent outcome rate was 79.7%. There were 13 patients with pain relief treated with reoperation. Postoperative complications included 10 cases of facial numbness, 1 case of intracranial infection, and 1 case of high-frequency hearing loss. The accuracy recognition of anatomic variation of the SPVC is crucial for the

Delayed facial nerve decompression for Bell's palsy.

PubMed

Kim, Sang Hoon; Jung, Junyang; Lee, Jong Ha; Byun, Jae Yong; Park, Moon Suh; Yeo, Seung Geun

2016-07-01

Incomplete recovery of facial motor function continues to be long-term sequelae in some patients with Bell's palsy. The purpose of this study was to investigate the efficacy of transmastoid facial nerve decompression after steroid and antiviral treatment in patients with late stage Bell's palsy. Twelve patients underwent surgical decompression for Bell's palsy 21-70 days after onset, whereas 22 patients were followed up after steroid and antiviral therapy without decompression. Surgical criteria included greater than 90 % degeneration on electroneuronography and no voluntary electromyography potentials. This study was a retrospective study of electrodiagnostic data and medical chart review between 2006 and 2013. Recovery from facial palsy was assessed using the House-Brackmann grading system. Final recovery rate did not differ significantly in the two groups; however, all patients in the decompression group recovered to at least House-Brackmann grade III at final follow-up. Although postoperative hearing threshold was increased in both groups, there was no significant between group difference in hearing threshold. Transmastoid decompression of the facial nerve in patients with severe late stage Bell's palsy at risk for a poor facial nerve outcome reduced severe complications of facial palsy with minimal morbidity.

Comparison of clinical outcomes in decompression and fusion versus decompression only in patients with ossification of the posterior longitudinal ligament: a meta-analysis.

PubMed

Mehdi, Syed K; Alentado, Vincent J; Lee, Bryan S; Mroz, Thomas E; Benzel, Edward C; Steinmetz, Michael P

2016-06-01

OBJECTIVE Ossification of the posterior longitudinal ligament (OPLL) is a pathological calcification or ossification of the PLL, predominantly occurring in the cervical spine. Although surgery is often necessary for patients with symptomatic neurological deterioration, there remains controversy with regard to the optimal surgical treatment. In this systematic review and meta-analysis, the authors identified differences in complications and outcomes after anterior or posterior decompression and fusion versus after decompression alone for the treatment of cervical myelopathy due to OPLL. METHODS A MEDLINE, SCOPUS, and Web of Science search was performed for studies reporting complications and outcomes after decompression and fusion or after decompression alone for patients with OPLL. A meta-analysis was performed to calculate effect summary mean values, 95% CIs, Q statistics, and I(2) values. Forest plots were constructed for each analysis group. RESULTS Of the 2630 retrieved articles, 32 met the inclusion criteria. There was no statistically significant difference in the incidence of excellent and good outcomes and of fair and poor outcomes between the decompression and fusion and the decompression-only cohorts. However, the decompression and fusion cohort had a statistically significantly higher recovery rate (63.2% vs 53.9%; p < 0.0001), a higher final Japanese Orthopaedic Association score (14.0 vs 13.5; p < 0.0001), and a lower incidence of OPLL progression (< 1% vs 6.3%; p < 0.0001) compared with the decompression-only cohort. There was no statistically significant difference in the incidence of complications between the 2 cohorts. CONCLUSIONS This study represents the only comprehensive review of outcomes and complications after decompression and fusion or after decompression alone for OPLL across a heterogeneous group of surgeons and patients. Based on these results, decompression and fusion is a superior surgical technique compared with posterior

Evaluation of the rate of decompression in anterior cervical corpectomy using an intra-operative computerized tomography scan (O-Arm system).

PubMed

Costa, Francesco; Tomei, Massimo; Sassi, Marco; Cardia, Andrea; Ortolina, Alessandro; Servello, Domenico; Fornari, Maurizio

2012-02-01

The purpose of this study was to evaluate the efficacy of intra-operative computerized tomography (CT) scanning in the analysis of bone removal accuracy during anterior cervical corpectomy, in order to allow any necessary immediate correction in the event of inadequate bone removal. From September 2009 to December 2010 we performed an intra-operative (CT) scan using the O-Arm(™) Image system to assess the rate of central and lateral decompression in all patients treated for cervical spondylotic myelopathy by anterior cervical corpectomy and fusion. Out of a population of 187 patients admitted to our department, with a diagnosis of myelopathy due to spondylotic degenerative cervical stenosis, 15 patients underwent a surgical treatment with anterior cervical corpectomy and fusion. There were nine males (60%) and six females (40%); the mean age was 52.4 years, ranging from 41 to 57 years. The pre-operative radiologic investigations (MRI and CT scans) revealed in the nine patients (60%) the extent of the compression to one vertebral body (C4 one case, C5 four cases, C6 four cases), while in the six cases (40%) the compression regarded two vertebral body (C3 and C4 one case, C4 and C5 two cases, C5 and C6 three cases). During surgery, when the decompression was judged completely, a CT scan was performed: in 11 cases (73.3%) the decompression was considered adequate, while in four cases (26.7%) it was deemed insufficient and the surgical strategy was changed in order to optimize the bone removal. In these cases an additional scan was taken to prove the efficacy of decompression, achieved in all patients. Intra-operative CT scan performed during cervical corpectomy is a really useful tool in helping to ensure complete bone removal and the adequacy of surgery. The O-arm(™) Image system grants optimal image quality, allowing correctly assessing the rate of decompression and, in any case of doubt, allows an intra-operative evaluation of the final correct positioning of

Timing of cranioplasty after decompressive craniectomy for trauma.

PubMed

Piedra, Mark P; Nemecek, Andrew N; Ragel, Brian T

2014-01-01

The optimal timing of cranioplasty after decompressive craniectomy for trauma is unknown. The aim of this study was to determine if early cranioplasty after decompressive craniectomy for trauma reduces complications. Consecutive cases of patients who underwent autologous cranioplasty after decompressive craniectomy for trauma at a single Level I Trauma Center were studied in a retrospective 10 year data review. Associations of categorical variables were compared using Chi-square test or Fisher's exact test. A total of 157 patients were divided into early (<12 weeks; 78 patients) and late (≥12 weeks; 79 patients) cranioplasty cohorts. Baseline characteristics were similar between the two cohorts. Cranioplasty operative time was significantly shorter in the early (102 minutes) than the late (125 minutes) cranioplasty cohort (P = 0.0482). Overall complication rate in both cohorts was 35%. Infection rates were lower in the early (7.7%) than the late (14%) cranioplasty cohort as was bone graft resorption (15% early, 19% late), hydrocephalus rate (7.7% early, 1.3% late), and postoperative hematoma incidence (3.9% early, 1.3% late). However, these differences were not statistically significant. Patients <18 years of age were at higher risk of bone graft resorption than patients ≥18 years of age (OR 3.32, 95% CI 1.25-8.81; P = 0.0162). After decompressive craniectomy for trauma, early (<12 weeks) cranioplasty does not alter the incidence of complication rates. In patients <18 years of age, early (<12 weeks) cranioplasty increases the risk of bone resorption. Delaying cranioplasty (≥12 weeks) results in longer operative times and may increase costs.

Joint pain and Doppler-detectable bubbles in altitude (Hypobaric) decompression

NASA Technical Reports Server (NTRS)

Powell, Michael R.

1993-01-01

The observation that altitude decompression sickness (DCS) is associated with pain in the lower extremities is not new, although it is not a consistent finding. DCS in divers is generally in the upper body, an effect often attributed to non-loading of the body while immersed. In caisson workers, DCS is reported more in the lower extremities. Surprisingly, many researchers do not mention the location of DCS joint pain, apparently considering it to be random. This is not the case for the tissue ratios encountered in studying decompression associated with simulated EVA. In NASA/JSC tests, altitude DCS generally presented first in either the ankle, knee, or hip (83 percent = 73/88). There was a definite statistical relation between the maximum Spencer precordial Doppler Grade and the incidence of DCS in the extremity, although this is not meant to imply a casual relation between circulating gas bubbles and joint pain. The risk of DCS with Grade 4 was considerably higher than that of Grades 0 to 3. The DCS risk was independent of the 'tissue ratio.' There was a predominance of lower extremity DCS even when exercise was performed with the upper body. The reason for these locations we hypothesize to be attributed to the formation of tissue gas micronuclei from kinetic and tensile forces (stress-assisted nucleation) and are the result of the individuals ambulating in a 1g environment. Additionally, since these showers of Doppler bubbles can persist for hours, it is difficult to imagine that they are emanating solely from tendons and ligaments, the supposed site of joint pain. This follows from Henry's law linking the volume of joint tissue (the solvent) and the solubility coefficient of inert gas; there is volumetrically insufficient connective tissue to produce the prolonged release of gas bubbles. If gas bubbles are spawned and released from connective tissue, their volume is increased by those from muscle tissue. Therefore, the nexus between Doppler-detectable gas

[Decompressive craniectomy in the management of sylvian infarction].

PubMed

Berhouma, Moncef; Khouja, Néjib; Jemel, Hafedh; Khaldi, Moncef

2006-09-01

Space-occupying middle cerebral artery infarction represents about 10 to 15% of supratentorial ischemic strokes. This syndrome carries a high rate of mortality and requires aggressive surgical decompression. The authors present 6 patients with signs of trans-tentorial herniation operated on between February 2001 and August 2003. Neurological preoperative status was evaluated with Glasgow coma scale score and postoperatively with Barthel index. Three patients had excellent recovery (Barthel Index up to 70), one remained dependant and two died. Younger patients had better prognosis. Decompressive surgery, when done early, should improve mortality rate and even functional outcome. Optimal selection of patients, with the help of Diffusion-Weighted imaging, could vouch good results.

Nerve decompression and neuropathy complications in diabetes: Are attitudes discordant with evidence?

PubMed Central

Nickerson, D. Scott

2017-01-01

ABSTRACT External neurolysis of the nerve at fibro-osseous tunnels has been proprosed to treat or prevent signs, symptoms, and complications in the lower extremity of diabetes patients with sensorimotor polyneuropathy. Nerve decompression is justified in the presence of symptomatic compressed nerves in the several fibro-osseous tunnels of the extremities, which are known to be frequent in diabetes. Quite a body of literature has accumulated reporting results after such nerve decompression in the leg, describing pain relief and sensibility improvement, as well as balance recovery, diabetic foot ulcer prevention, curtailed ulcer recurrence risk, and amputation avoidance. Historical academic hesitance to endorse surgical treatments for pain and numbness in diabetes was based primarily on the early retrospective reports’ potential for bias and placebo effects, and that the hypothetical basis for surgery lies outside the traditional etiology paradigm of length-dependent axonopathy. This reticence is here critiqued in view of recent studies using objective, measured outcome protocols which nullify such potential confounders. Pain relief is now confirmed with Level 1 studies, and Level 2 prospective information suggests protection from initial diabetic foot ulceration and most neuropathic ulcer recurrences. In view of the potential for nerve decompression to be useful in addressing some of the more difficult, expensive, and life altering complications of diabetic neuropathy, this secondary compression thesis and operative treatment methodology may deserve reassessment. PMID:28959382

Lethality and injuring the effect of compression and decompression rates of high hydrostatic pressure on Escherichia coli O157:H7 in different matrices

NASA Astrophysics Data System (ADS)

Syed, Qamar Abbas; Buffa, Martin; Guamis, Buenaventura; Saldo, Jordi

2013-03-01

The effect of compression and decompression rates of high hydrostatic pressure (HHP) on Escherichia coli O157:H7 was investigated. Samples of orange juice, skimmed milk and Tris buffer were inoculated with E. coli O157:H7 and subjected to 600 MPa for 3 min at 4°C with fast, medium and slow compression and decompression. Analyses immediately after HHP treatment revealed that E. coli in milk and juice treated with fast compression suffered more than slow compression rates. Slow decompression resulted in higher inactivation of E. coli in all matrices. After overnight storage, highest stress-recovery (1.19 log cfu/mL) was observed in Tris buffer. Healthy cells were<1 log cfu/mL in milk and buffer samples, but no growth was detected in orange juice for any of the treatments immediately after HHP. After 15 days at 4°C, E. coli cells in skimmed milk and Tris buffer recovered significantly, whereas the recovery of sublethally injured cells was inhibited in orange juice.

Decompression Surgery Alone Versus Decompression Plus Fusion in Symptomatic Lumbar Spinal Stenosis: A Swiss Prospective Multicenter Cohort Study With 3 Years of Follow-up.

PubMed

Ulrich, Nils H; Burgstaller, Jakob M; Pichierri, Giuseppe; Wertli, Maria M; Farshad, Mazda; Porchet, François; Steurer, Johann; Held, Ulrike

2017-09-15

Retrospective analysis of a prospective, multicenter cohort study. To estimate the added effect of surgical fusion as compared to decompression surgery alone in symptomatic lumbar spinal stenosis patients with spondylolisthesis. The optimal surgical management of lumbar spinal stenosis patients with spondylolisthesis remains controversial. Patients of the Lumbar Stenosis Outcome Study with confirmed DLSS and spondylolisthesis were enrolled in this study. The outcomes of this study were Spinal Stenosis Measure (SSM) symptoms (score range 1-5, best-worst) and function (1-4) over time, measured at baseline, 6, 12, 24, and 36 months follow-up. In order to quantify the effect of fusion surgery as compared to decompression alone and number of decompressed levels, we used mixed effects models and accounted for the repeated observations in main outcomes (SSM symptoms and SSM function) over time. In addition to individual patients' random effects, we also fitted random slopes for follow-up time points and compared these two approaches with Akaike's Information Criterion and the chi-square test. Confounders were adjusted with fixed effects for age, sex, body mass index, diabetes, Cumulative Illness Rating Scale musculoskeletal disorders, and duration of symptoms. One hundred thirty-one patients undergoing decompression surgery alone (n = 85) or decompression with fusion surgery (n = 46) were included in this study. In the multiple mixed effects model the adjusted effect of fusion compared with decompression alone surgery on SSM symptoms was 0.06 (95% confidence interval: -0.16-0.27) and -0.07 (95% confidence interval: -0.25-0.10) on SSM function, respectively. Among the patients with degenerative lumbar spinal stenosis and spondylolisthesis our study confirms that in the two groups, decompression alone and decompression with fusion, patients distinctively benefited from surgical treatment. When adjusted for confounders, fusion surgery was not associated with a more

[A clinical study on different decompression methods in cervical spondylosis].

PubMed

Ma, Xun; Zhao, Xiao-fei; Zhao, Yi-bo

2009-04-15

To analyze the different decompression methods to treat cervical spondylosis based on imageological evaluation. Two hundred and sixty three consecutive patients with cervical spondylosis between Nov. 2004 and Oct. 2007 were involved in this study. Patients were distributed to different operation groups based on the preoperative imageological evaluation, including anterior or posterior decompression methods. The Anterior method is to use the discectomy of one to three segments, autogenous iliac graft or titanium mesh or cage fusion and titanium plate fixation, or subtotal vertebrectomy of one to two segments autogenous iliac graft or titanium mesh fusion and titanium plate fixation, or discectomy plus subtotal vertebrectomy, The posterior expansive single open door laminoplasty and other operation types. All the patients were divided into different groups by the preoperative imageological evaluation, age, sex and course of diseases. Then we collected each group's preoperative and postoperative JOA scores and mean improvement rate to evaluate the postoperative effect by different decompression methods. Two hundred and thirty five patients were followed up with a mean period of 18 months (range, 4 to 36 months). JOA scores of all patients were improved by different degrees after operations. Anterior and posterior decompression methods both can achieve higher mean improvement rates. There were no significant differences in mean improvement rates between anterior groups, and so did male and female (P > 0.05). The effect will decrease as age increases or the course of disease prolongs. Statistical significance existed among the different age groups and between course groups (P < 0.05). Anterior and posterior decompression methods both can achieve good effect. The key point is to choose the surgical indication correctly, decompress thoroughly, and make the fusion reliable and fixation firm. In regard to the patients' imageological evaluation, the methods should be

Predictors of surgical revision after in situ decompression of the ulnar nerve.

PubMed

Krogue, Justin D; Aleem, Alexander W; Osei, Daniel A; Goldfarb, Charles A; Calfee, Ryan P

2015-04-01

This study was performed to identify factors associated with the need for revision surgery after in situ decompression of the ulnar nerve for cubital tunnel syndrome. This case-control investigation examined all patients treated at one institution with open in situ decompression for cubital tunnel syndrome between 2006 and 2011. The case patients were 44 failed decompressions that required revision, and the controls were 79 randomly selected patients treated with a single operation. Demographic data and disease-specific data were extracted from the medical records. The rate of revision surgery after in situ decompression was determined from our 5-year experience. A multivariate logistic regression model was used based on univariate testing to determine predictors of revision cubital tunnel surgery. Revision surgery was required in 19% (44 of 231) of all in situ decompressions performed during the study period. Predictors of revision surgery included a history of elbow fracture or dislocation (odds ratio [OR], 7.1) and McGowan stage I disease (OR, 3.2). Concurrent surgery with in situ decompression was protective against revision surgery (OR, 0.19). The rate of revision cubital tunnel surgery after in situ nerve decompression should be weighed against the benefits of a less invasive procedure compared with transposition. When considering in situ ulnar nerve decompression, prior elbow fracture as well as patients requesting surgery for mild clinically graded disease should be viewed as risk factors for revision surgery. Patient factors often considered relevant to surgical outcomes, including age, sex, body mass index, tobacco use, and diabetes status, were not associated with a greater likelihood of revision cubital tunnel surgery. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The effect of nonlinear decompression history on H2O/CO2 vesiculation in rhyolitic magmas

NASA Astrophysics Data System (ADS)

Su, Yanqing; Huber, Christian

2017-04-01

Magma ascent rate is one of the key parameters that control volcanic eruption style, tephra dispersion, and volcanic atmospheric impact. Many methods have been employed to investigate the magma ascent rate in volcanic eruptions, and most rely on equilibrium thermodynamics. Combining the mixed H2O-CO2 solubility model with the diffusivities of both H2O and CO2 for normal rhyolitic melt, we model the kinetics of H2O and CO2 in rhyolitic eruptions that involve nonlinear decompression rates. Our study focuses on the effects of the total magma ascent time, the nonlinearity of decompression paths, and the influence of different initial CO2/H2O content on the posteruptive H2O and CO2 concentration profiles around bubbles within the melt. Our results show that, under most circumstances, volatile diffusion profiles do not constrain a unique solution for the decompression rate of magmas during an eruption, but, instead, provide a family of decompression paths with a well-defined trade-off between ascent time and nonlinearity. An important consequence of our analysis is that the common assumption of a constant decompression rate (averaged value) tends to underestimate the actual magma ascent time.

Can Fan-Beam Interactive Computed Tomography Accurately Predict Indirect Decompression in Minimally Invasive Spine Surgery Fusion Procedures?

PubMed

Janssen, Insa; Lang, Gernot; Navarro-Ramirez, Rodrigo; Jada, Ajit; Berlin, Connor; Hilis, Aaron; Zubkov, Micaella; Gandevia, Lena; Härtl, Roger

2017-11-01

Recently, novel mobile intraoperative fan-beam computed tomography (CT) was introduced, allowing for real-time navigation and immediate intraoperative evaluation of neural decompression in spine surgery. This study sought to investigate whether intraoperatively assessed neural decompression during minimally invasive spine surgery (MISS) has a predictive value for clinical and radiographic outcome. A retrospective study of patients undergoing intraoperative CT (iCT)-guided extreme lateral interbody fusion or transforaminal lumbar interbody fusion was conducted. 1) Preoperative, 2) intraoperative (after cage implantation, 3) postoperative, and 4) follow-up radiographic and clinical parameters obtained from radiography or CT were quantified. Thirty-four patients (41 spinal segments) were analyzed. iCT-based navigation was successfully accomplished in all patients. Radiographic parameters showed significant improvement from preoperatively to intraoperatively after cage implantation in both MISS procedures (extreme lateral interbody fusion/transforaminal lumbar interbody fusion) (P ≤ 0.05). Radiologic parameters for both MISS fusion procedures did not show significant differences to the assessed radiographic measures at follow-up (P > 0.05). Radiologic outcome values did not decrease when compared intraoperatively (after cage implantation) to latest follow-up. Intraoperative fan-beam CT is capable of assessing neural decompression intraoperatively with high accuracy, allowing for precise prediction of radiologic outcome and earliest possible feedback during MISS fusion procedures. These findings are highly valuable for routine practice and future investigations toward finding a threshold for neural decompression that translates into clinical improvement. If sufficient neural decompression has been confirmed with iCT imaging studies, additional postoperative and/or follow-up imaging studies might no longer be required if patients remain asymptomatic. Copyright © 2017

Use of psychological decompression in military operational environments.

PubMed

Hughes, Jamie G H Hacker; Earnshaw, N Mark; Greenberg, Neil; Eldridge, Rod; Fear, Nicola T; French, Claire; Deahl, Martin P; Wessely, Simon

2008-06-01

This article reviews the use of psychological decompression as applied to troops returning from active service in operational theaters. Definitions of the term are considered and a brief history is given. Current policies and practices are described and the question of mandatory decompression is considered. Finally, the evidence base for the efficacy of decompression is examined and some conclusions are drawn. This article highlights variations in the definition and practice of decompression and its use. Although there is, as yet, no evidence that decompression works, there is also no evidence to the contrary. Given the lack of knowledge as to the balance of risks and benefits of decompression and the absence of any definitive evidence that decompression is associated with improved mental health outcomes or that lack of decompression is associated with the reverse, it is argued that the use of decompression should remain a matter for discretion.

The mechanics of decompressive craniectomy: Bulging in idealized geometries

NASA Astrophysics Data System (ADS)

Weickenmeier, Johannes; Kuhl, Ellen; Goriely, Alain

2016-11-01

In extreme cases of traumatic brain injury or a stroke, the resulting uncontrollable swelling of the brain may lead to a harmful increase of the intracranial pressure. As a common measure for immediate release of pressure on the brain, part of the skull is surgically removed allowing for the brain to bulge outwards, a procedure known as a decompressive craniectomy. During this excessive brain swelling, the affected tissue typically undergoes large deformations resulting in a complex three-dimensional mechanical loading state with several important implications on optimal treatment strategies and outcome. Here, as a first step towards a better understanding of the mechanics of a decompressive craniectomy, we consider simple models for the bulging of elastic solids under geometric constraints representative of the surgical intervention. In small deformations and simple geometries, the exact solution of this problem is derived from the theory of contact mechanics. The analysis of these solutions reveals a number of interesting generic features relevant for the mechanics of craniectomy.

Gas embolization of the liver in a rat model of rapid decompression.

PubMed

L'Abbate, Antonio; Kusmic, Claudia; Matteucci, Marco; Pelosi, Gualtiero; Navari, Alessandro; Pagliazzo, Antonino; Longobardi, Pasquale; Bedini, Remo

2010-08-01

Occurrence of liver gas embolism after rapid decompression was assessed in 31 female rats that were decompressed in 12 min after 42 min of compression at 7 ATA (protocol A). Sixteen rats died after decompression (group I). Of the surviving rats, seven were killed at 3 h (group II), and eight at 24 h (group III). In group I, bubbles were visible in the right heart, aortic arch, liver, and mesenteric veins and on the intestinal surface. Histology showed perilobular microcavities in sinusoids, interstitial spaces, and hepatocytes. In group II, liver gas was visible in two rats. Perilobular vacuolization and significant plasma aminotransferase increase were present. In group III, liver edema was evident at gross examination in all cases. Histology showed perilobular cell swelling, vacuolization, or hydropic degeneration. Compared with basal, enzymatic markers of liver damage increased significantly. An additional 14 rats were decompressed twice (protocol B). Overall mortality was 93%. In addition to diffuse hydropic degeneration, centrilobular necrosis was frequently observed after the second decompression. Additionally, 10 rats were exposed to three decompression sessions (protocol C) with doubled decompression time. Their mortality rate decreased to 20%, but enzymatic markers still increased in surviving rats compared with predecompression, and perilobular cell swelling and vacuolization were present in five rats. Study challenges were 1) liver is not part of the pathophysiology of decompression in the existing paradigm, and 2) although significant cellular necrosis was observed in few animals, zonal or diffuse hepatocellular damage associated with liver dysfunction was frequently demonstrated. Liver participation in human decompression sickness should be looked for and clinically evaluated.

The Extended Oxygen Window Concept for Programming Saturation Decompressions Using Air and Nitrox

PubMed Central

Kot, Jacek; Sicko, Zdzislaw

2015-01-01

Saturation decompression is a physiological process of transition from one steady state, full saturation with inert gas at pressure, to another one: standard conditions at surface. It is defined by the borderline condition for time spent at a particular depth (pressure) and inert gas in the breathing mixture (nitrogen, helium). It is a delicate and long lasting process during which single milliliters of inert gas are eliminated every minute, and any disturbance can lead to the creation of gas bubbles leading to decompression sickness (DCS). Most operational procedures rely on experimentally found parameters describing a continuous slow decompression rate. In Poland, the system for programming of continuous decompression after saturation with compressed air and nitrox has been developed as based on the concept of the Extended Oxygen Window (EOW). EOW mainly depends on the physiology of the metabolic oxygen window—also called inherent unsaturation or partial pressure vacancy—but also on metabolism of carbon dioxide, the existence of water vapor, as well as tissue tension. Initially, ambient pressure can be reduced at a higher rate allowing the elimination of inert gas from faster compartments using the EOW concept, and maximum outflow of nitrogen. Then, keeping a driving force for long decompression not exceeding the EOW allows optimal elimination of nitrogen from the limiting compartment with half-time of 360 min. The model has been theoretically verified through its application for estimation of risk of decompression sickness in published systems of air and nitrox saturation decompressions, where DCS cases were observed. Clear dose-reaction relation exists, and this confirms that any supersaturation over the EOW creates a risk for DCS. Using the concept of the EOW, 76 man-decompressions were conducted after air and nitrox saturations in depth range between 18 and 45 meters with no single case of DCS. In summary, the EOW concept describes physiology of

Timing of cranioplasty after decompressive craniectomy for ischemic or hemorrhagic stroke.

PubMed

Piedra, Mark P; Ragel, Brian T; Dogan, Aclan; Coppa, Nicholas D; Delashaw, Johnny B

2013-01-01

The optimal timing of cranioplasty after decompressive craniectomy for stroke is not known. Case series suggest that early cranioplasty is associated with higher rates of infection while delaying cranioplasty may be associated with higher rates of bone resorption. The authors examined whether the timing of cranioplasty after decompressive craniectomy for stroke affects postoperative complication rates. A retrospective cohort study was undertaken to evaluate complication rates in patients undergoing cranioplasty at early (within 10 weeks of craniectomy) or late (≥ 10 weeks) stages. Multivariate logistic regression analysis was used to determine characteristics that would predict complications in patients undergoing cranioplasty after decompressive craniectomy for stroke. While the overall complication rate was higher in the early cranioplasty cohort (22% vs 16% in the late cranioplasty cohort), the difference was not statistically significant (p = 0.5541). Patients in the early cranioplasty cohort had lower rates of postoperative hematoma but higher rates of infection. Presence of a CSF shunt was the only significant predictor of complications (OR 8.96, 95% CI 1.84-43.6). Complications rates for early cranioplasty (within 10 weeks of craniectomy) are similar to those encountered when cranioplasty is delayed, although the cohort size in this study was too small to state equivalence. Patients with a ventriculoperitoneal shunt are at higher risk for complications after cranioplasty.

The effects of different rates of ascent on the incidence of altitude decompression sickness

NASA Technical Reports Server (NTRS)

Kumar, K. V.; Waligora, James M.

1989-01-01

The effect of different rates of ascent on the incidence of altitude decompression sickness (DCS) was analyzed by a retrospective study on 14,123 man-flights involving direct ascent up to 38,000 ft altitude. The data were classified on the basis of altitude attained, denitrogenation at ground level, duration of stay at altitude, rest or exercise while at altitude, frequency of exercise at altitude, and ascent rates. This database was further divided on the basis of ascent rates into different groups from 1000 ft/min up to 53,000 ft/min. The database was analyzed using multiple correlation and regression methods, and the results of the analysis reveal that ascent rates influence the incidence of DCS in combination with the various factors mentioned above. Rate of ascent was not a significant predictor of DCS and showed a low, but significant multiple correlation (R=0.31) with the above factors. Further, the effects of rates below 2500 ft/min are significantly different from that of rates above 2500 ft/min on the incidence of symptoms (P=0.03) and forced descent (P=0.01). At rates above 2500 ft/min and up to 53,000 ft/min, the effects of ascent rates are not significantly different (P greater than 0.05) in the population examined while the effects of rates below 2500 ft/min are not clear.

Decompression experiments identify kinetic controls on explosive silicic eruptions

USGS Publications Warehouse

Mangan, M.T.; Sisson, T.W.; Hankins, W.B.

2004-01-01

Eruption intensity is largely controlled by decompression-induced release of water-rich gas dissolved in magma. It is not simply the amount of gas that dictates how forcefully magma is propelled upwards during an eruption, but also the rate of degassing, which is partly a function of the supersaturation pressure (??Pcritical) triggering gas bubble nucleation. High temperature and pressure decompression experiments using rhyolite and dacite melt reveal compositionally-dependent differences in the ??Pcritical of degassing that may explain why rhyolites have fueled some of the most explosive eruptions on record.

Severe capillary leak syndrome after inner ear decompression sickness in a recreational scuba diver.

PubMed

Gempp, Emmanuel; Lacroix, Guillaume; Cournac, Jean-Marie; Louge, Pierre

2013-07-01

Post-decompression shock with plasma volume deficit is a very rare event that has been observed under extreme conditions of hypobaric and hyperbaric exposure in aviators and professional divers. We report a case of severe hypovolemic shock due to extravasation of plasma in a recreational scuba diver presenting with inner ear decompression sickness. Impaired endothelial function can lead to capillary leak with hemoconcentration and hypotension in severe cases. This report suggests that decompression-induced circulating bubbles may have triggered the endothelial damage, activating the classic inflammatory pathway of increased vascular permeability. This observation highlights the need for an accurate diagnosis of this potentially life-threatening condition at the initial presentation in the Emergency Department after a diving-related injury. An elevated hematocrit in a diver should raise the suspicion for the potential development of capillary leak syndrome requiring specific treatment using albumin infusion as primary fluid replacement. Copyright © 2013 Elsevier Inc. All rights reserved.

Piezosurgery in Modified Pterional Orbital Decompression Surgery in Graves Disease.

PubMed

Grauvogel, Juergen; Scheiwe, Christian; Masalha, Waseem; Jarc, Nadja; Grauvogel, Tanja; Beringer, Andreas

2017-10-01

Piezosurgery uses microvibrations to selectively cut bone, preserving the adjacent soft tissue. The present study evaluated the use of piezosurgery for bone removal in orbital decompression surgery in Graves disease via a modified pterional approach. A piezosurgical device (Piezosurgery medical) was used in 14 patients (20 orbits) with Graves disease who underwent orbital decompression surgery in additional to drills and rongeurs for bone removal of the lateral orbital wall and orbital roof. The practicability, benefits, and drawbacks of this technique in orbital decompression surgery were recorded. Piezosurgery was evaluated with respect to safety, preciseness of bone cutting, and preservation of the adjacent dura and periorbita. Preoperative and postoperative clinical outcome data were assessed. The orbital decompression surgery was successful in all 20 orbits, with good clinical outcomes and no postoperative complications. Piezosurgery proved to be a safe tool, allowing selective bone cutting with no damage to the surrounding soft tissue structures. However, there were disadvantages concerning the intraoperative handling in the narrow space and the efficiency of bone removal was limited in the orbital decompression surgery compared with drills. Piezosurgery proved to be a useful tool in bone removal for orbital decompression in Graves disease. It is safe and easy to perform, without any danger of damage to adjacent tissue because of its selective bone-cutting properties. Nonetheless, further development of the device is necessary to overcome the disadvantages in intraoperative handling and the reduced bone removal rate. Copyright © 2017 Elsevier Inc. All rights reserved.

Systematic review of intraoperative colonic irrigation vs. manual decompression in obstructed left-sided colorectal emergencies.

PubMed

Kam, M H; Tang, C L; Chan, E; Lim, J F; Eu, K W

2009-09-01

A systematic review was conducted to determine if manual decompression is a safe alternative to intraoperative colonic irrigation prior to primary anastomosis in obstructed left-sided colorectal emergencies. Search for relevant articles from 1980 to 2007 was conducted on Medline, Embase and the Cochrane Controlled Trials Register using the keywords "colonic lavage, irrigation, decompression, washout, obstructed and bowel preparation", either singularly or in combination. Trials in English publications with similar patient characteristics, inclusion criteria and outcome measures were selected for analysis. Thirty-day mortality, anastomotic leak rates and post-operative wound infection were studied as outcome variables. Analysis was performed with RevMan 4.2 software. Seven trials were identified for systematic review, with a total of 449 patients. Data from the single randomised controlled trial and one prospective comparative trial were analysed separately. Results from the remaining five studies were pooled into two arms of a composite series, one with colonic irrigation and one without. Results showed no significant difference in the anastomotic leak rates and mortality rates between the colonic irrigation and manual decompression arms in the randomised and comparative trials. The composite series, however, showed significantly better results with manual decompression (RR 6.18, 95% CI 1.67-22.86). The post-operative infection rate was similar in both groups. Manual decompression was comparable to colonic irrigation for primary anastomosis in obstructed left-sided colorectal emergencies, with no significant increase in mortality, leak or infection rates.

Deep lateral wall orbital decompression following strabismus surgery in patients with Type II ophthalmic Graves' disease.

PubMed

Ellis, Michael P; Broxterman, Emily C; Hromas, Alan R; Whittaker, Thomas J; Sokol, Jason A

2018-01-10

Surgical management of ophthalmic Graves' disease traditionally involves, in order, orbital decompression, followed by strabismus surgery and eyelid surgery. Nunery et al. previously described two distinct sub-types of patients with ophthalmic Graves' disease; Type I patients exhibit no restrictive myopathy (no diplopia) as opposed to Type II patients who do exhibit restrictive myopathy (diplopia) and are far more likely to develop new-onset worsening diplopia following medial wall and floor decompression. Strabismus surgery involving extra-ocular muscle recession has, in turn, been shown to potentially worsen proptosis. Our experience with Type II patients who have already undergone medial wall and floor decompression and strabismus surgery found, when additional decompression is necessary, deep lateral wall decompression (DLWD) appears to have a low rate of post-operative primary-gaze diplopia. A case series of four Type II ophthalmic Graves' disease patients, all of whom had already undergone decompression and strabismus surgery, and went on to develop worsening proptosis or optic nerve compression necessitating further decompression thereafter. In all cases, patients were treated with DLWD. Institutional Review Board approval was granted by the University of Kansas. None of the four patients treated with this approach developed recurrent primary-gaze diplopia or required strabismus surgery following DLWD. While we still prefer to perform medial wall and floor decompression as the initial treatment for ophthalmic Graves' disease, for proptosis following consecutive strabismus surgery, DLWD appears to be effective with a low rate of recurrent primary-gaze diplopia.

Potential Fifty Percent Reduction in Saturation Diving Decompression Time Using a Combination of Intermittent Recompression and Exercise

NASA Technical Reports Server (NTRS)

Gernhardt, Michael I.; Abercromby, Andrew; Conklin, Johnny

2007-01-01

Conventional saturation decompression protocols use linear decompression rates that become progressively slower at shallower depths, consistent with free gas phase control vs. dissolved gas elimination kinetics. If decompression is limited by control of free gas phase, linear decompression is an inefficient strategy. The NASA prebreathe reduction program demonstrated that exercise during O2 prebreathe resulted in a 50% reduction (2 h vs. 4 h) in the saturation decompression time from 14.7 to 4.3 psi and a significant reduction in decompression sickness (DCS: 0 vs. 23.7%). Combining exercise with intermittent recompression, which controls gas phase growth and eliminates supersaturation before exercising, may enable more efficient saturation decompression schedules. A tissue bubble dynamics model (TBDM) was used in conjunction with a NASA exercise prebreathe model (NEPM) that relates tissue inert gas exchange rate constants to exercise (ml O2/kg-min), to develop a schedule for decompression from helium saturation at 400 fsw. The models provide significant prediction (p < 0.001) and goodness of fit with 430 cases of DCS in 6437 laboratory dives for TBDM (p = 0.77) and with 22 cases of DCS in 159 altitude exposures for NEPM (p = 0.70). The models have also been used operationally in over 25,000 dives (TBDM) and 40 spacewalks (NEPM). The standard U.S. Navy (USN) linear saturation decompression schedule from saturation at 400 fsw required 114.5 h with a maximum Bubble Growth Index (BGI(sub max)) of 17.5. Decompression using intermittent recompression combined with two 10 min exercise periods (75% VO2 (sub peak)) per day required 54.25 h (BGI(sub max): 14.7). Combined intermittent recompression and exercise resulted in a theoretical 53% (2.5 day) reduction in decompression time and theoretically lower DCS risk compared to the standard USN decompression schedule. These results warrant future decompression trials to evaluate the efficacy of this approach.

Needle Decompression of Tension Pneumothorax with Colorimetric Capnography.

PubMed

Naik, Nimesh D; Hernandez, Matthew C; Anderson, Jeff R; Ross, Erika K; Zielinski, Martin D; Aho, Johnathon M

2017-11-01

The success of needle decompression for tension pneumothorax is variable, and there are no objective measures assessing effective decompression. Colorimetric capnography, which detects carbon dioxide present within the pleural space, may serve as a simple test to assess effective needle decompression. Three swine underwent traumatically induced tension pneumothorax (standard of care, n = 15; standard of care with needle capnography, n = 15). Needle thoracostomy was performed with an 8-cm angiocatheter. Similarly, decompression was performed with the addition of colorimetric capnography. Subjective operator assessment of decompression was recorded and compared with true decompression, using thoracoscopic visualization for both techniques. Areas under receiver operating curves were calculated and pairwise comparison was performed to assess statistical significance (P < .05). The detection of decompression by needle colorimetric capnography was found to be 100% accurate (15 of 15 attempts), when compared with thoracoscopic assessment (true decompression). Furthermore, it accurately detected the lack of tension pneumothorax, that is, the absence of any pathologic/space-occupying lesion, in 100% of cases (10 of 10 attempts). Standard of care needle decompression was detected by operators in 9 of 15 attempts (60%) and was detected in 3 of 10 attempts when tension pneumothorax was not present (30%). True decompression, under direct visualization with thoracoscopy, occurred 15 of 15 times (100%) with capnography, and 12 of 15 times (80%) without capnography. Areas under receiver operating curves were 0.65 for standard of care and 1.0 for needle capnography (P = .002). Needle decompression with colorimetric capnography provides a rapid, effective, and highly accurate method for eliminating operator bias for tension pneumothorax decompression. This may be useful for the treatment of this life-threatening condition. Copyright © 2017 American College of Chest Physicians

Surgical decompression is associated with decreased mortality in patients with sepsis and ureteral calculi.

PubMed

Borofsky, Michael S; Walter, Dawn; Shah, Ojas; Goldfarb, David S; Mues, Adam C; Makarov, Danil V

2013-03-01

The combination of sepsis and ureteral calculus is a urological emergency. Traditional teaching advocates urgent decompression with nephrostomy tube or ureteral stent placement, although published outcomes validating this treatment are lacking. National practice patterns for such scenarios are currently undefined. Using a retrospective study design, we defined the surgical decompression rate in patients admitted to the hospital with severe infection and ureteral calculi. We determined whether a mortality benefit is associated with this intervention. Patient demographics and hospital characteristics were extracted from the 2007 to 2009 Nationwide Inpatient Sample. We identified 1,712 patients with ureteral calculi and sepsis. Multivariate logistic regression was performed to determine the association between mortality and surgical decompression. Of the patients 78% underwent surgical decompression. Mortality was higher in those not treated with surgical decompression (19.2% vs 8.82%, p <0.001). Lack of surgical decompression was independently associated with an increased OR of mortality even when adjusting for patient demographics, comorbidities and geographic region of treatment (OR 2.6, 95% CI 1.9-3.7). Absent surgical decompression is associated with higher odds of mortality in patients with sepsis and ureteral calculi. Further research to determine predictors of surgical decompression is necessary to ensure that all patients have access to this life saving therapy. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Decompression scenarios in a new underground transportation system.

PubMed

Vernez, D

2000-10-01

The risks of a public exposure to a sudden decompression, until now, have been related to civil aviation and, at a lesser extent, to diving activities. However, engineers are currently planning the use of low pressure environments for underground transportation. This method has been proposed for the future Swissmetro, a high-speed underground train designed for inter-urban linking in Switzerland. The use of a low pressure environment in an underground public transportation system must be considered carefully regarding the decompression risks. Indeed, due to the enclosed environment, both decompression kinetics and safety measures may differ from aviation decompression cases. A theoretical study of decompression risks has been conducted at an early stage of the Swissmetro project. A three-compartment theoretical model, based on the physics of fluids, has been implemented with flow processing software (Ithink 5.0). Simulations have been conducted in order to analyze "decompression scenarios" for a wide range of parameters, relevant in the context of the Swissmetro main study. Simulation results cover a wide range from slow to explosive decompression, depending on the simulation parameters. Not surprisingly, the leaking orifice area has a tremendous impact on barotraumatic effects, while the tunnel pressure may significantly affect both hypoxic and barotraumatic effects. Calculations have also shown that reducing the free space around the vehicle may mitigate significantly an accidental decompression. Numeric simulations are relevant to assess decompression risks in the future Swissmetro system. The decompression model has proven to be useful in assisting both design choices and safety management.

Effects of decompression on operator performance.

DOT National Transportation Integrated Search

1966-04-01

The study was performed to provide more quantitative estimates of degradation of pilot performance following decompression and the extent to which a decompression with mask donning interrupts the task of piloting. The experiments utilized a Scow comp...

Extreme-value dependence: An application to exchange rate markets

NASA Astrophysics Data System (ADS)

Fernandez, Viviana

2007-04-01

Extreme value theory (EVT) focuses on modeling the tail behavior of a loss distribution using only extreme values rather than the whole data set. For a sample of 10 countries with dirty/free float regimes, we investigate whether paired currencies exhibit a pattern of asymptotic dependence. That is, whether an extremely large appreciation or depreciation in the nominal exchange rate of one country might transmit to another. In general, after controlling for volatility clustering and inertia in returns, we do not find evidence of extreme-value dependence between paired exchange rates. However, for asymptotic-independent paired returns, we find that tail dependency of exchange rates is stronger under large appreciations than under large depreciations.

Xenon Blocks Neuronal Injury Associated with Decompression

PubMed Central

Blatteau, Jean-Eric; David, Hélène N.; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H.

2015-01-01

Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS. PMID:26469983

Xenon Blocks Neuronal Injury Associated with Decompression.

PubMed

Blatteau, Jean-Eric; David, Hélène N; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H

2015-10-15

Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS.

Decompression models: review, relevance and validation capabilities.

PubMed

Hugon, J

2014-01-01

For more than a century, several types of mathematical models have been proposed to describe tissue desaturation mechanisms in order to limit decompression sickness. These models are statistically assessed by DCS cases, and, over time, have gradually included bubble formation biophysics. This paper proposes to review this evolution and discuss its limitations. This review is organized around the comparison of decompression model biophysical criteria and theoretical foundations. Then, the DCS-predictive capability was analyzed to assess whether it could be improved by combining different approaches. Most of the operational decompression models have a neo-Haldanian form. Nevertheless, bubble modeling has been gaining popularity, and the circulating bubble amount has become a major output. By merging both views, it seems possible to build a relevant global decompression model that intends to simulate bubble production while predicting DCS risks for all types of exposures and decompression profiles. A statistical approach combining both DCS and bubble detection databases has to be developed to calibrate a global decompression model. Doppler ultrasound and DCS data are essential: i. to make correlation and validation phases reliable; ii. to adjust biophysical criteria to fit at best the observed bubble kinetics; and iii. to build a relevant risk function.

Modified Veress needle decompression of tension pneumothorax: a randomized crossover animal study.

PubMed

Lubin, Dafney; Tang, Andrew L; Friese, Randall S; Martin, Matthew; Green, D J; Jones, Trevor; Means, Russell R; Ginwalla, Rashna; O'Keeffe, Terence S; Joseph, Bellal A; Wynne, Julie L; Kulvatunyou, Narong; Vercruysse, Gary; Gries, Lynn; Rhee, Peter

2013-12-01

The current prehospital standard of care using a large bore intravenous catheter for tension pneumothorax (tPTX) decompression is associated with a high failure rate. We developed a modified Veress needle (mVN) for this condition. The purpose of this study was to evaluate the effectiveness and safety of the mVN as compared with a 14-gauge needle thoracostomy (NT) in a swine tPTX model. tPTX was created in 16 adult swine via thoracic CO2 insufflation to 15 mm Hg. After tension physiology was achieved, defined as a 50% reduction of cardiac output, the swine were randomized to undergo either mVN or NT decompression. Failure to restore 80% baseline systolic blood pressure within 5 minutes resulted in crossover to the alternate device. The success rate of each device, death, and need for crossover were analyzed using χ. Forty-three tension events were created in 16 swine (24 mVN, 19 NT) at 15 mm Hg of intrathoracic pressure with a mean CO2 volume of 3.8 L. tPTX resulted in a 48% decline of systolic blood pressure from baseline and 73% decline of cardiac output, and 42% had equalization of central venous pressure with pulmonary capillary wedge pressure. All tension events randomized to mVN were successfully rescued within a mean (SD) of 70 (86) seconds. NT resulted in four successful decompressions (21%) within a mean (SD) of 157 (96) seconds. Four swine (21%) died within 5 minutes of NT decompression. The persistent tension events where the swine survived past 5 minutes (11 of 19 NTs) underwent crossover mVN decompression, yielding 100% rescue. Neither the mVN nor the NT was associated with inadvertent injuries to the viscera. Thoracic insufflation produced a reliable and highly reproducible model of tPTX. The mVN is vastly superior to NT for effective and safe tPTX decompression and physiologic recovery. Further research should be invested in the mVN for device refinement and replacement of NT in the field.

Surgical orbital decompression for thyroid eye disease.

PubMed

Boboridis, Kostas G; Bunce, Catey

2011-12-07

RCTs reviewed are not robust enough to provide credible evidence to our understanding of current decompressive surgery and to support recommendations for clinical practice. There is evidence from currently available uncontrolled studies that removal of the medial and lateral wall (balanced decompression) with or without fat removal may be the most effective surgical method related to only a few complications.There is a clear need for randomised studies evaluating the balanced two-wall, three-wall and orbital fat decompression techniques. Comparison with other surgical techniques for orbital decompression or with immunosuppression in cases of compressive optic neuropathy would also be important. These studies should primarily address the reduction of exophthalmos, disease severity, complication rates, quality of life and cost of the intervention.

Simulation of gas bubbles in hypobaric decompressions: roles of O2, CO2, and H2O.

PubMed

Van Liew, H D; Burkard, M E

1995-01-01

To gain insight into the special features of bubbles that may form in aviators and astronauts, we simulated the growth and decay of bubbles in two hypobaric decompressions and a hyperbaric one, all with the same tissue ratio (TR), where TR is defined as tissue PN2 before decompression divided by barometric pressure after. We used an equation system which is solved by numerical methods and accounts for simultaneous diffusion of any number of gases as well as other major determinants of bubble growth and absorption. We also considered two extremes of the number of bubbles which form per unit of tissue. A) Because physiological mechanisms keep the partial pressures of the "metabolic" gases (O2, CO2, and H2O) nearly constant over a range of hypobaric pressures, their fractions in bubbles are inversely proportional to pressure and their large volumes at low pressure add to bubble size. B) In addition, the large fractions facilitate the entry of N2 into bubbles, and when bubble density is low, enhance an autocatalytic feedback on bubble growth due to increasing surface area. C) The TR is not closely related to bubble size; that is when two different decompressions have the same TR, metabolic gases cause bubbles to grow larger at lower hypobaric pressures. We conclude that the constancy of partial pressures of metabolic gases, unimportant in hyperbaric decompressions, affects bubble size in hypobaric decompressions in inverse relation to the exposure pressure.

[Patent foramen ovale and decompression illness in divers].

PubMed

Sivertsen, Wiebke; Risberg, Jan; Norgård, Gunnar

2010-04-22

About 25 % of the population has patent foramen ovale, and the condition has been assumed to be a causal factor in decompressive illness. Transcatheter closure is possible and is associated with a relatively low risk, but it has not been clarified whether there is an indication for assessment and treatment of the condition in divers. The present study explored a possible relationship between a patent foramen ovale and the risk for decompression illness in divers, if there are categories of divers that should be screened for the condition and what advice should be given to divers with this condition. The review is based on literature identified through a search in Pubmed and the authors' long clinical experience in the field. The risk of decompression illness for divers with a persistent foramen ovale is about five times higher than that in divers without this condition, but the absolute risk for decompression illness is only 2.5 after 10,000 dives. A causal association has not been shown between patent foramen ovale and decompression illness. Even if closure of patent foramen ovale may be done with relatively small risk, the usefulness of the procedure has not been documented in divers. We do not recommend screening for patent foramen ovale in divers because the absolute risk of decompression illness is small and transcatheter closure is only indicated after decompression illness in some occupational divers.

The physiological kinetics of nitrogen and the prevention of decompression sickness.

PubMed

Doolette, D J; Mitchell, S J

2001-01-01

Decompression sickness (DCS) is a potentially crippling disease caused by intracorporeal bubble formation during or after decompression from a compressed gas underwater dive. Bubbles most commonly evolve from dissolved inert gas accumulated during the exposure to increased ambient pressure. Most diving is performed breathing air, and the inert gas of interest is nitrogen. Divers use algorithms based on nitrogen kinetic models to plan the duration and degree of exposure to increased ambient pressure and to control their ascent rate. However, even correct execution of dives planned using such algorithms often results in bubble formation and may result in DCS. This reflects the importance of idiosyncratic host factors that are difficult to model, and deficiencies in current nitrogen kinetic models. Models describing the exchange of nitrogen between tissues and blood may be based on distributed capillary units or lumped compartments, either of which may be perfusion- or diffusion-limited. However, such simplistic models are usually poor predictors of experimental nitrogen kinetics at the organ or tissue level, probably because they fail to account for factors such as heterogeneity in both tissue composition and blood perfusion and non-capillary exchange mechanisms. The modelling of safe decompression procedures is further complicated by incomplete understanding of the processes that determine bubble formation. Moreover, any formation of bubbles during decompression alters subsequent nitrogen kinetics. Although these factors mandate complex resolutions to account for the interaction between dissolved nitrogen kinetics and bubble formation and growth, most decompression schedules are based on relatively simple perfusion-limited lumped compartment models of blood: tissue nitrogen exchange. Not surprisingly, all models inevitably require empirical adjustment based on outcomes in the field. Improvements in the predictive power of decompression calculations are being

Decompressive craniectomy with massive intractable intraoperative cerebral edema: utilization of silicone sheet for temporary scalp closure.

PubMed

Ahmadian, Amir; Baa J, Ali A; Garcia, Michael; Carey, Carolyn; Rodriguez, Luis; Storrs, Bruce; Tuite, Gerald F

2012-09-01

The authors present a case of extreme brain herniation encountered during decompressive craniectomy in a 21-month-old boy who suffered a trauma event that necessitated temporary scalp closure in which a sterile silicone sheet was placed. Although the clinical situation is usually expected to lead to brain death or severe disability, the patient's 3-year follow-up examination revealed a highly functional child with a good quality of life. The authors discuss the feasibility and advantages of temporary scalp expansion as a treatment option when extreme brain herniation is encountered during craniotomy.

Comparison of clinical outcomes between laminoplasty, posterior decompression with instrumented fusion, and anterior decompression with fusion for K-line (-) cervical ossification of the posterior longitudinal ligament.

PubMed

Koda, Masao; Mochizuki, Makondo; Konishi, Hiroaki; Aiba, Atsuomi; Kadota, Ryo; Inada, Taigo; Kamiya, Koshiro; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Yamazaki, Masashi; Mannoji, Chikato; Furuya, Takeo

2016-07-01

The K-line, which is a virtual line that connects the midpoints of the anteroposterior diameter of the spinal canal at C2 and C7 in a plain lateral radiogram, is a useful preoperative predictive indicator for sufficient decompression by laminoplasty (LMP) for ossification of the posterior longitudinal ligament (OPLL). K-line is defined as (+) when the peak of OPLL does not exceed the K-line, and is defined as (-) when the peak of OPLL exceeds the K-line. For patients with K-line (-) OPLL, LMP often results in poor outcome. The aim of the present study was to compare the clinical outcome of LMP, posterior decompression with instrumented fusion (PDF) and anterior decompression and fusion (ADF) for patients with K-line (-) OPLL. The present study included patients who underwent surgical treatment including LMP, PDF and ADF for K-line (-) cervical OPLL. We retrospectively compared the clinical outcome of those patients in terms of Japanese Orthopedic Association score (JOA score) recovery rate. JOA score recovery rate was significantly higher in the ADF group compared with that in the LMP group and the PDF group. The JOA score recovery rate in the PDF group was significantly higher than that in the LMP group. LMP should not be used for K-line (-) cervical OPLL. ADF is one of the suitable surgical treatments for K-line (-) OPLL. Both ADF and PDF are applicable for K-line (-) OPLL according to indications set by each institute and surgical decisions.

Lumbar spinous process splitting decompression provides equivalent outcomes to conventional midline decompression in degenerative lumbar canal stenosis: a prospective, randomized controlled study of 51 patients.

PubMed

Rajasekaran, S; Thomas, Ashok; Kanna, Rishi M; Prasad Shetty, Ajoy

2013-09-15

Prospective, randomized controlled study. To compare the functional outcomes and extent of paraspinal muscle damage between 2 decompressive techniques for lumbar canal stenosis. Lumbar spinous process splitting decompression (LSPSD) preserves the muscular and liga-mentous attachments of the posterior elements of the spine. It can potentially avoid problems such as paraspinal muscle atrophy and trunk extensor weakness that can occur after conventional midline decompression. However, large series prospective randomized controlled studies are lacking. Patients with lumbar canal stenosis were randomly allocated into 2 groups: LSPSD (28 patients) and conventional midline decompression (23 patients). The differences in operative time, blood loss, time to comfortable mobilization, and hospital stay were studied. Paraspinal muscle damage was assessed by postoperative rise in creatine phosphokinase and C-reactive protein levels. Functional outcome was evaluated at 1 year by Japanese Orthopaedic Association score, neurogenic claudication outcome score, and visual analogue scale for back pain and neurogenic claudication. Fifty-one patients of mean age 56 years were followed-up for a mean 14.2 ± 2.9 months. There were no significant differences in the operative time, blood loss, and hospital stay. Both the groups showed significant improvement in the functional outcome scores at 1 year. Between the 2 groups, the Japanese Orthopaedic Association score, neurogenic claudication outcome score improvement, visual analogue scale for back pain, neurogenic claudication visual analogue scale, and the postoperative changes in serum C-reactive protein and creatine phosphokinase levels did not show any statistically significant difference. On the basis of the Japanese Orthopaedic Association recovery rate, it was found that 73.9% of conventional midline decompression group had good outcomes compared with only 60.7% after LSPSD. The functional outcome scores, back pain, and claudication

Effect of oxygen-breathing during a decompression-stop on bubble-induced platelet activation after an open-sea air dive: oxygen-stop decompression.

PubMed

Pontier, J-M; Lambrechts, K

2014-06-01

We highlighted a relationship between decompression-induced bubble formation and platelet micro-particle (PMP) release after a scuba air-dive. It is known that decompression protocol using oxygen-stop accelerates the washout of nitrogen loaded in tissues. The aim was to study the effect of oxygen deco-stop on bubble formation and cell-derived MP release. Healthy experienced divers performed two scuba-air dives to 30 msw for 30 min, one with an air deco-stop and a second with 100% oxygen deco-stop at 3 msw for 9 min. Bubble grades were monitored with ultrasound and converted to the Kisman integrated severity score (KISS). Blood samples for cell-derived micro-particle analysis (AnnexinV for PMP and CD31 for endothelial MP) were taken 1 h before and after each dive. Mean KISS bubble score was significantly lower after the dive with oxygen-decompression stop, compared to the dive with air-decompression stop (4.3 ± 7.3 vs. 32.7 ± 19.9, p < 0.001). After the dive with an air-breathing decompression stop, we observed an increase of the post-dive mean values of PMP (753 ± 245 vs. 381 ± 191 ng/μl, p = 0.003) but no significant change in the oxygen-stop decompression dive (329 ± 215 vs. 381 +/191 ng/μl, p = 0.2). For the post-dive mean values of endothelial MP, there was no significant difference between both the dives. The Oxygen breathing during decompression has a beneficial effect on bubble formation accelerating the washout of nitrogen loaded in tissues. Secondary oxygen-decompression stop could reduce bubble-induced platelet activation and the pro-coagulant activity of PMP release preventing the thrombotic event in the pathogenesis of decompression sickness.

Hypobaric decompression prebreathe requirements and breathing environment

NASA Technical Reports Server (NTRS)

Webb, James T.; Pilmanis, Andrew A.

1993-01-01

To reduce incidence of decompression sickness (DCS), prebreathing 100 percent oxygen to denitrogenate is required prior to hypobaric decompressions from a sea level pressure breathing environment to pressures lower than 350 mm Hg (20,000 ft; 6.8 psia). The tissue ratio (TR) of such exposures equals or exceeds 1.7; TR being the tissue nitrogen pressure prior to decompression divided by the total pressure after decompression (((0.781)(14.697))/6.758). Designing pressure suits capable of greater pressure differentials, lower TR's, and procedures which limit the potential for DCS occurrence would enhance operational efficiency. The current 10.2 psia stage decompression prior to extravehicular activity (EVA) from the Shuttle in the 100 percent oxygen, 4.3 psia suit, results in a TR of 1.65 and has proven to be relatively free of DCS. Our recent study of zero-prebreathe decompressions to 6.8 psia breathing 100 percent oxygen (TR = 1.66) also resulted in no DCS (N = 10). The level of severe, Spencer Grades 3 or 4, venous gas emboli (VGE) increased from 0 percent at 9.5 psia to 40 percent at 6.8 psia yielding a Probit curve of VGE risk for the 51 male subjects who participated in these recent studies. Earlier, analogous decompressions using a 50 percent oxygen, 50 percent nitrogen breathing mixture resulted in one case of DCS and significantly higher levels of severe VGE, e.g., at 7.8 psia, the mixed gas breathing environment resulted in a 56 percent incidence of severe VGE versus 10 percent with use of 100 percent oxygen. The report of this study recommended use of 100 percent oxygen during zero-prebreathe exposure to 6.8 psia if such a suit could be developed. For future, long-term missions, we suggest study of the effects of decompression over several days to a breathing environment of 150 mmHg O2 and approximately 52 mmHg He as a means of eliminating DCS and VGE hazards during subsequent excursions. Once physiologically adapted to a 4 psia vehicle, base, or space

Graphics processing unit-assisted lossless decompression

DOEpatents

Loughry, Thomas A.

2016-04-12

Systems and methods for decompressing compressed data that has been compressed by way of a lossless compression algorithm are described herein. In a general embodiment, a graphics processing unit (GPU) is programmed to receive compressed data packets and decompress such packets in parallel. The compressed data packets are compressed representations of an image, and the lossless compression algorithm is a Rice compression algorithm.

[Orbital decompression in Grave's ophtalmopathy].

PubMed

Longueville, E

2010-01-01

Graves disease orbitopathy is a complex progressive inflammatory disease. Medical treatment remains in all cases the proposed treatment of choice. Surgical treatment by bone decompression can be considered as an emergency mainly in cases of optic neuropathy or ocular hypertension not being controlled medically or in post-traumatic exophthalmos stage. Emergency bone decompression eliminates compression or stretching of the optic nerve allowing visual recovery. The uncontrolled ocular hypertension will benefit from decompression. The normalization of intraocular pressure may be obtained by this surgery or if needed by the use of postoperative antiglaucoma drops or even filtration surgery. In all operated cases, the IOP was normalized with an average decrease of 7.71 mmHg and a cessation of eye drops in 3/7 cases. Regarding sequelae, our therapeutic strategy involves consecutively surgery of the orbit, extraocular muscles and eyelids. The orbital expansion gives excellent results on the cosmetic level and facilitates the implementation of subsequent actions.

Pictorial essay: Role of ultrasound in failed carpal tunnel decompression.

PubMed

Botchu, Rajesh; Khan, Aman; Jeyapalan, Kanagaratnam

2012-01-01

USG has been used for the diagnosis of carpal tunnel syndrome. Scarring and incomplete decompression are the main causes for persistence or recurrence of symptoms. We performed a retrospective study to assess the role of ultrasound in failed carpal tunnel decompression. Of 422 USG studies of the wrist performed at our center over the last 5 years, 14 were for failed carpal tunnel decompression. Scarring was noted in three patients, incomplete decompression in two patients, synovitis in one patient, and an anomalous muscle belly in one patient. No abnormality was detected in seven patients. We present a pictorial review of USG findings in failed carpal tunnel decompression.

Pictorial essay: Role of ultrasound in failed carpal tunnel decompression

PubMed Central

Botchu, Rajesh; Khan, Aman; Jeyapalan, Kanagaratnam

2012-01-01

USG has been used for the diagnosis of carpal tunnel syndrome. Scarring and incomplete decompression are the main causes for persistence or recurrence of symptoms. We performed a retrospective study to assess the role of ultrasound in failed carpal tunnel decompression. Of 422 USG studies of the wrist performed at our center over the last 5 years, 14 were for failed carpal tunnel decompression. Scarring was noted in three patients, incomplete decompression in two patients, synovitis in one patient, and an anomalous muscle belly in one patient. No abnormality was detected in seven patients. We present a pictorial review of USG findings in failed carpal tunnel decompression. PMID:22623813

Transcranial Doppler ultrasound and the etiology of neurologic decompression sickness during altitude decompression

NASA Technical Reports Server (NTRS)

Norfleet, W. T.; Powell, M. R.; Kumar, K. Vasantha; Waligora, J.

1993-01-01

The presence of gas bubbles in the arterial circulation can occur from iatrogenic mishaps, cardiopulmonary bypass devices, or following decompression, e.g., in deep-sea or SCUBA diving or in astronauts during extravehicular activities (EVA). We have examined the pathophysiology of neurological decompression sickness in human subjects who developed a large number of small gas bubbles in the right side of the heart as a result of hypobaric exposures. In one case, gas bubbles were detected in the middle cerebral artery (MCA) and the subject developed neurological symptoms; a 'resting' patent foramen ovalae (PFO) was found upon saline contrast echocardiography. A PFO was also detected in another individual who developed Spencer Grade 4 precordial Doppler ultrasound bubbles, but no evidence was seen of arterialization of bubbles upon insonation of either the MCA or common carotid artery. The reason for this difference in the behavior of intracardiac bubbles in these two individuals is not known. To date, we have not found evidence of right-to-left shunting of bubbles through pulmonary vasculature. The volume of gas bubbles present following decompression is examined and compared with the number arising from saline contrast injection. The estimates are comparable.

Orbital fat decompression for thyroid eye disease: retrospective case review and criteria for optimal case selection.

PubMed

Prat, Marta Calsina; Braunstein, Alexandra L; Dagi Glass, Lora R; Kazim, Michael

2015-01-01

The purpose of this study is to identify the subgroups of thyroid eye disease (TED) patients most likely to benefit from orbital fat decompression. This retrospective study reviews 217 orbits of 109 patients who underwent orbital fat decompression for proptosis secondary to thyroid eye disease. Charts were reviewed for demographic, radiographic, clinical, and surgical data. Three groups of patients were defined for the purposes of statistical analysis: those with proptosis secondary to expansion of the fat compartment (group I), those with proptosis secondary to enlargement of the extraocular muscles (group II), and those with proptosis secondary to enlargement of both fat and muscle (group III). Groups I and II, and those patients with greater preoperative proptosis and those with a history of radiation therapy were most likely to benefit from orbital fat decompression. However, even those in group III or with lesser proptosis appreciated significant benefit. While orbital fat decompression can and, at times, should be combined with bone decompression to treat proptosis resulting from thyroid eye disease, orbital fat decompression alone is associated with lower rates of surgical morbidity, and is especially effective for group I and II patients, those with greater preoperative proptosis, and those with a history of radiation.

Decompression sickness in breath-hold divers: a review.

PubMed

Lemaitre, Frederic; Fahlman, Andreas; Gardette, Bernard; Kohshi, Kiyotaka

2009-12-01

Although it has been generally assumed that the risk of decompression sickness is virtually zero during a single breath-hold dive in humans, repeated dives may result in a cumulative increase in the tissue and blood nitrogen tension. Many species of marine mammals perform extensive foraging bouts with deep and long dives interspersed by a short surface interval, and some human divers regularly perform repeated dives to 30-40 m or a single dive to more than 200 m, all of which may result in nitrogen concentrations that elicit symptoms of decompression sickness. Neurological problems have been reported in humans after single or repeated dives and recent necropsy reports in stranded marine mammals were suggestive of decompression sickness-like symptoms. Modelling attempts have suggested that marine mammals may live permanently with elevated nitrogen concentrations and may be at risk when altering their dive behaviour. In humans, non-pathogenic bubbles have been recorded and symptoms of decompression sickness have been reported after repeated dives to modest depths. The mechanisms implicated in these accidents indicate that repeated breath-hold dives with short surface intervals are factors that predispose to decompression sickness. During deep diving, the effect of pulmonary shunts and/or lung collapse may play a major role in reducing the incidence of decompression sickness in humans and marine mammals.

Facial nerve decompression surgery using bFGF-impregnated biodegradable gelatin hydrogel in patients with Bell palsy.

PubMed

Hato, Naohito; Nota, Jumpei; Komobuchi, Hayato; Teraoka, Masato; Yamada, Hiroyuki; Gyo, Kiyofumi; Yanagihara, Naoaki; Tabata, Yasuhiko

2012-04-01

Basic fibroblast growth factor (bFGF) promotes the regeneration of denervated nerves. The aim of this study was to evaluate the regeneration-facilitating effects of novel facial nerve decompression surgery using bFGF in a gelatin hydrogel in patients with severe Bell palsy. Prospective clinical study. Tertiary referral center. Twenty patients with Bell palsy after more than 2 weeks following the onset of severe paralysis were treated with the new procedure. The facial nerve was decompressed between tympanic and mastoid segments via the mastoid. A bFGF-impregnated biodegradable gelatin hydrogel was placed around the exposed nerve. Regeneration of the facial nerve was evaluated by the House-Brackmann (H-B) grading system. The outcomes were compared with the authors' previous study, which reported outcomes of the patients who underwent conventional decompression surgery (n = 58) or conservative treatment (n = 43). The complete recovery (H-B grade 1) rate of the novel surgery (75.0%) was significantly better than the rate of conventional surgery (44.8%) and conservative treatment (23.3%). Every patient in the novel decompression surgery group improved to H-B grade 2 or better even when undergone between 31 and 99 days after onset. Advantages of this decompression surgery are low risk of complications and long effective period after onset of the paralysis. To the authors' knowledge, this is the first clinical report of the efficacy of bFGF using a new drug delivery system in patients with severe Bell palsy.

Do modern techniques improve core decompression outcomes for hip osteonecrosis?

PubMed

Marker, David R; Seyler, Thorsten M; Ulrich, Slif D; Srivastava, Siddharth; Mont, Michael A

2008-05-01

Core decompression procedures have been used in osteonecrosis of the femoral head to attempt to delay the joint destruction that may necessitate hip arthroplasty. The efficacy of core decompressions has been variable with many variations of technique described. To determine whether the efficacy of this procedure has improved during the last 15 years using modern techniques, we compared recently reported radiographic and clinical success rates to results of surgeries performed before 1992. Additionally, we evaluated the outcomes of our cohort of 52 patients (79 hips) who were treated with multiple small-diameter drillings. There was a decrease in the proportion of patients undergoing additional surgeries and an increase in radiographic success when comparing pre-1992 results to patients treated in the last 15 years. However, there were fewer Stage III hips in the more recent reports, suggesting that patient selection was an important reason for this improvement. The results of the small-diameter drilling cohort were similar to other recent reports. Patients who had small lesions and were Ficat Stage I had the best results with 79% showing no radiographic progression. Our study confirms core decompression is a safe and effective procedure for treating early stage femoral head osteonecrosis.

Greater occipital nerve excision for occipital neuralgia refractory to nerve decompression.

PubMed

Ducic, Ivica; Felder, John M; Khan, Neelam; Youn, Sojin

2014-02-01

Patients who undergo occipital nerve decompression for treatment of migraine headaches due to occipital neuralgia have already exhausted medical options for treatment. When surgical decompression fails, it is unknown how best to help these patients. We examine our experience performing greater occipital nerve (GON) excision for pain relief in this select, refractory group of patients. A retrospective chart review supplemented by a follow-up survey was performed on all patients under the care of the senior author who had undergone GON excision after failing occipital nerve decompression. Headache severity was measured by the migraine headache index (MHI) and disability by the migraine disability assessment. Success rate was considered the percentage of patients who experienced a 50% or greater reduction in MHI at final follow-up. Seventy-one of 108 patients responded to the follow-up survey and were included in the study. Average follow-up was 33 months. The success rate of surgery was 70.4%; 41% of patients showed a 90% or greater decrease in MHI. The MHI changed, on average, from 146 to 49, for an average reduction of 63% (P < 0.001). Migraine disability assessment scores decreased by an average of 49% (P < 0.001). Multivariate analysis revealed that a diagnosis of cervicogenic headache was associated with failure of surgery. The most common adverse effect was bothersome numbness or hypersensitivity in the denervated area, occurring in up to 31% of patients. Excision of the GON is a valid option for pain relief in patients with occipital headaches refractory to both medical treatment and surgical decompression. Potential risks include failure in patients with cervicogenic headache and hypersensitivity of the denervated area. To provide the best outcome to these patients who have failed all previous medical and surgical treatments, a multidisciplinary team approach remains critical.

Edema and elasticity of a fronto-temporal decompressive craniectomy

PubMed Central

Takada, Daikei; Nagai, Hidemasa; Moritake, Kouzo; Akiyama, Yasuhiko

2012-01-01

Background: Decompressive craniectomy is undertaken for relief of brain herniation caused by acute brain swelling. Brain stiffness can be estimated by palpating the decompressive cranial defect and can provide some relatively subjective information to the neurosurgeon to help guide care. The goal of the present study was to objectively evaluate transcutaneous stiffness of the cranial defect using a tactile resonance sensor and to describe the values in patients with a decompressive window in order to characterize the clinical association between brain edema and stiffness. Methods: Data were prospectively collected from 13 of 37 patients who underwent a decompressive craniectomy in our hospital during a 5-year period. Transcutaneous stiffness was measured as change in frequency and as elastic modulus. Results: Stiffness variables of the decompressive site were measured without any adverse effect and subsequent calculations revealed change in frequency = 101.71 ± 36.42 Hz, and shear elastic modulus = 1.99 ± 1.11 kPa. Conclusions: The elasticity of stiffness of a decompressive site correlated with brain edema, cisternal cerebrospinal fluid pressure, and brain shift, all of which are related to acute brain edema. PMID:22347679

Oxygen Equipment and Rapid Decompression Studies

DTIC Science & Technology

1979-03-01

defined and discussed by Fritz Haber anti Hans Clamann (3) of the USAF School of Aviation Medicine.* These authors define two factors in a...for the pattern of airflow through the pene- tration; and (vi) maintenance of critical flow. The equation for rapid decompression as presented by Haber ...galley, controlling the pressure differential between the two compartments. Using the equation of Haber and Clamann (7), a decompression for the galley

Salvage C2 ganglionectomy after C2 nerve root decompression provides similar pain relief as a single surgical procedure for intractable occipital neuralgia.

PubMed

Pisapia, Jared M; Bhowmick, Deb A; Farber, Roger E; Zager, Eric L

2012-02-01

To determine the effectiveness of C2 nerve root decompression and C2 dorsal root ganglionectomy for intractable occipital neuralgia (ON) and C2 ganglionectomy after pain recurrence following initial decompression. A retrospective review was performed of the medical records of patients undergoing surgery for ON. Pain relief at the time of the most recent follow-up was rated as excellent (headache relieved), good (headache improved), or poor (headache unchanged or worse). Telephone contact supplemented chart review, and patients rated their preoperative and postoperative pain on a 10-point numeric scale. Patient satisfaction and disability were also examined. Of 43 patients, 29 were available for follow-up after C2 nerve root decompression (n = 11), C2 dorsal root ganglionectomy (n = 10), or decompression followed by ganglionectomy (n = 8). Overall, 19 of 29 patients (66%) experienced a good or excellent outcome at most recent follow-up. Among the 19 patients who completed the telephone questionnaire (mean follow-up 5.6 years), patients undergoing decompression, ganglionectomy, or decompression followed by ganglionectomy experienced similar outcomes, with mean pain reduction ratings of 5 ± 4.0, 4.5 ± 4.1, and 5.7 ± 3.5. Of 19 telephone responders, 13 (68%) rated overall operative results as very good or satisfactory. In the third largest series of surgical intervention for ON, most patients experienced favorable postoperative pain relief. For patients with pain recurrence after C2 decompression, salvage C2 ganglionectomy is a viable surgical option and should be offered with the potential for complete pain relief and improved quality of life (QOL). Copyright © 2012. Published by Elsevier Inc.

Comparison of Clinical and Radiologic Results of Mini-Open Transforaminal Lumbar Interbody Fusion and Extreme Lateral Interbody Fusion Indirect Decompression for Degenerative Lumbar Spondylolisthesis

PubMed Central

Gen, Hogaku; Sakuma, Yoshio; Koshika, Yasuhide

2018-01-01

Study Design Retrospective study. Purpose In this study, we compared the postoperative outcomes of extreme lateral interbody fusion (XLIF) indirect decompression with that of mini-open transforaminal lumbar interbody fusion (TLIF) in patients with lumbar degenerative spondylolisthesis. Overview of Literature There are very few reports examining postoperative results of XLIF and minimally invasive TLIF for degenerative lumbar spondylolisthesis, and no reports comparing XLIF and mini-open TLIF. Methods Forty patients who underwent 1-level spinal fusion, either by XLIF indirect decompression (X group, 20 patients) or by mini-open TLIF (T group, 20 patients), for treatment of lumbar degenerative spondylolisthesis were included in this study. Invasiveness of surgery was evaluated on the basis of surgery time, blood loss, hospitalization period, and perioperative complications. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), disc angle (DA), disc height (DH), and slipping length (SL) were evaluated before surgery, immediately after surgery, and at 12 months after surgery. Cross-sectional spinal canal area (CSA) was also measured before surgery and at 1 month after surgery. Results There was no significant difference between the groups in terms of surgery time or hospitalization period; however, X group showed a significant decrease in blood loss (p<0.001). Serious complications were not observed in either group. In clinical assessment, no significant differences were observed between the groups with regard to the JOABPEQ results. The change in DH at 12 months after surgery increased significantly in the X group (p<0.05), and the changes in DA and SL were not significantly different between the two groups. The change in CSA was significantly greater in the T group (p<0.001). Conclusions Postoperative clinical results were equally favorable for both procedures; however, in comparison with mini-open TLIF, less blood loss and greater

Comparison of Clinical and Radiologic Results of Mini-Open Transforaminal Lumbar Interbody Fusion and Extreme Lateral Interbody Fusion Indirect Decompression for Degenerative Lumbar Spondylolisthesis.

PubMed

Kono, Yutaka; Gen, Hogaku; Sakuma, Yoshio; Koshika, Yasuhide

2018-04-01

Retrospective study. In this study, we compared the postoperative outcomes of extreme lateral interbody fusion (XLIF) indirect decompression with that of mini-open transforaminal lumbar interbody fusion (TLIF) in patients with lumbar degenerative spondylolisthesis. There are very few reports examining postoperative results of XLIF and minimally invasive TLIF for degenerative lumbar spondylolisthesis, and no reports comparing XLIF and mini-open TLIF. Forty patients who underwent 1-level spinal fusion, either by XLIF indirect decompression (X group, 20 patients) or by mini-open TLIF (T group, 20 patients), for treatment of lumbar degenerative spondylolisthesis were included in this study. Invasiveness of surgery was evaluated on the basis of surgery time, blood loss, hospitalization period, and perioperative complications. The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), disc angle (DA), disc height (DH), and slipping length (SL) were evaluated before surgery, immediately after surgery, and at 12 months after surgery. Cross-sectional spinal canal area (CSA) was also measured before surgery and at 1 month after surgery. There was no significant difference between the groups in terms of surgery time or hospitalization period; however, X group showed a significant decrease in blood loss ( p <0.001). Serious complications were not observed in either group. In clinical assessment, no significant differences were observed between the groups with regard to the JOABPEQ results. The change in DH at 12 months after surgery increased significantly in the X group ( p <0.05), and the changes in DA and SL were not significantly different between the two groups. The change in CSA was significantly greater in the T group ( p <0.001). Postoperative clinical results were equally favorable for both procedures; however, in comparison with mini-open TLIF, less blood loss and greater correction of DH were observed in XLIF.

Could some aviation deep vein thrombosis be a form of decompression sickness?

PubMed

Buzzacott, Peter; Mollerlokken, Andreas

2016-10-01

Aviation deep vein thrombosis is a challenge poorly understood in modern aviation. The aim of the present project was to determine if cabin decompression might favor formation of vascular bubbles in commercial air travelers. Thirty commercial flights were taken. Cabin pressure was noted at take-off and at every minute following, until the pressure stabilized. These time-pressure profiles were imported into the statistics program R and analyzed using the package SCUBA. Greatest pressure differentials between tissues and cabin pressures were estimated for 20, 40, 60, 80 and 120 min half-time compartments. Time to decompress ranged from 11 to 47 min. The greatest drop in cabin pressure was from 1022 to 776 mBar, equivalent to a saturated diver ascending from 2.46 msw depth. Mean pressure drop in flights >2 h duration was 193 mBar, while mean pressure drop in flights <2 h was 165 mBar. The greatest drop in pressure over 1 min was 28 mBar. Over 30 commercial flights it was found that the drop in cabin pressure was commensurate with that found to cause bubbles in man. Both the US Navy and the Royal Navy mandate far slower decompression from states of saturation, being 1.7 and 1.9 mBar/min respectively. The median overall rate of decompression found in this study was 8.5 mBar/min, five times the rate prescribed for USN saturation divers. The tissues associated with hypobaric bubble formation are likely slower than those associated with bounce diving, with 60 min a potentially useful index.

Continuous decompression of unicameral bone cyst with cannulated screws: a comparative study.

PubMed

Brecelj, Janez; Suhodolcan, Lovro

2007-09-01

We determined the role of mechanical decompression in the resolution of unicameral bone cyst. A total of 69 children with unicameral bone cysts were treated either by (i) open curettage and bone grafting, (ii) steroid injection or (iii) cannulated screw insertion. During a mean follow-up of 69 months (range, 12-58), the cysts were evaluated by radiological criteria. The healing rates in the three groups were 25, 12 and 29% after the first treatment, and a further 50, 19 and 65% after the second. The study has demonstrated the advantages of the decompression technique for unicameral bone cysts over other treatment modalities studied.

Percutaneous laser disc decompression versus conventional microdiscectomy for patients with sciatica: Two-year results of a randomised controlled trial.

PubMed

Brouwer, Patrick A; Brand, Ronald; van den Akker-van Marle, M Elske; Jacobs, Wilco Ch; Schenk, Barry; van den Berg-Huijsmans, Annette A; Koes, Bart W; Arts, Mark A; van Buchem, M A; Peul, Wilco C

2017-06-01

Background Percutaneous laser disc decompression is a minimally invasive treatment, for lumbar disc herniation and might serve as an alternative to surgical management of sciatica. In a randomised trial with two-year follow-up we assessed the clinical effectiveness of percutaneous laser disc decompression compared to conventional surgery. Materials and methods This multicentre randomised prospective trial with a non-inferiority design, was carried out according to an intent-to-treat protocol with full institutional review board approval. One hundred and fifteen eligible surgical candidates, with sciatica from a disc herniation smaller than one-third of the spinal canal, were randomly allocated to percutaneous laser disc decompression ( n = 55) or conventional surgery ( n = 57). The main outcome measures for this trial were the Roland-Morris Disability Questionnaire for sciatica, visual analogue scores for back and leg pain and the patient's report of perceived recovery. Results The primary outcome measures showed no significant difference or clinically relevant difference between the two groups at two-year follow-up. The re-operation rate was 21% in the surgery group, which is relatively high, and with an even higher 52% in the percutaneous laser disc decompression group. Conclusion At two-year follow-up, a strategy of percutaneous laser disc decompression, followed by surgery if needed, resulted in non-inferior outcomes compared to a strategy of microdiscectomy. Although the rate of reoperation in the percutaneous laser disc decompression group was higher than expected, surgery could be avoided in 48% of those patients that were originally candidates for surgery. Percutaneous laser disc decompression, as a non-surgical method, could have a place in the treatment arsenal of sciatica caused by contained herniated discs.

Original endoscopic orbital decompression of lateral wall through hairline approach for Graves' ophthalmopathy: an innovation of balanced orbital decompression.

PubMed

Gong, Yi; Yin, Jiayang; Tong, Boding; Li, Jingkun; Zeng, Jiexi; Zuo, Zhongkun; Ye, Fei; Luo, Yongheng; Xiao, Jing; Xiong, Wei

2018-01-01

Orbital decompression is an important surgical procedure for treatment of Graves' ophthalmopathy (GO), especially in women. It is reasonable for balanced orbital decompression of the lateral and medial wall. Various surgical approaches, including endoscopic transnasal surgery for medial wall and eye-side skin incision surgery for lateral wall, are being used nowadays, but many of them lack the validity, safety, or cosmetic effect. Endoscopic orbital decompression of lateral wall through hairline approach and decompression of medial wall via endoscopic transnasal surgery was done to achieve a balanced orbital decompression, aiming to improve the appearance of proptosis and create conditions for possible strabismus and eyelid surgery afterward. From January 29, 2016 to February 14, 2017, this surgery was performed on 41 orbits in 38 patients with GO, all of which were at inactive stage of disease. Just before surgery and at least 3 months after surgery, Hertel's ophthalmostatometer and computed tomography (CT) were used to check proptosis and questionnaires of GO quality of life (QOL) were completed. The postoperative retroversion of eyeball was 4.18±1.11 mm (Hertel's ophthalmostatometer) and 4.17±1.14 mm (CT method). The patients' QOL was significantly improved, especially the change in appearance without facial scar. The only postoperative complication was local soft tissue depression at temporal region. Obvious depression occurred in four cases (9.76%), which can be repaired by autologous fat filling. This surgery is effective, safe, and cosmetic. Effective balanced orbital decompression can be achieved by using this original and innovative surgery method. The whole manipulation is safe and controllable under endoscope. The postoperative scar of endoscopic surgery through hairline approach is covered by hair and the anatomic structure of anterior orbit is not impacted.

Decompression of keratocystic odontogenic tumors leading to increased fibrosis, but without any change in epithelial proliferation.

PubMed

Awni, Sarah; Conn, Brendan

2017-06-01

The aim of this study was to investigate whether decompression treatment induces changes in the histology or biologic behavior of keratocystic odontogenic tumor (KCOT). Seventeen patients with KCOT underwent decompression treatment with or without enucleation. Histologic evaluation and immunohistochemical expression of p53, Ki-67, and Bcl-2 were analyzed by using conventional microscopy. KCOT showed significantly increased fibrosis (P = .01) and a subjective reduction in mitotic activity (P = .03) after decompression. There were no statistically significant changes in the expression of proliferation markers. An increase in daughter-cysts or epithelial rests was seen after decompression (P = .04). Recurrence was noted in four of 16 cases, and expression of p53 was strongly correlated with prolonged duration of treatment (P = .01) and intense inflammatory changes (P = .02). Structural changes in the KCOT epithelium or capsule following decompression facilitate surgical removal of the tumor. There was no statistical evidence that decompression influences expression of proliferation markers in the lining, indicating that the potential for recurrence may not be restricted to the cellular level. The statistically significant increase of p53 expression with increased duration of treatment and increase of inflammation may also indicate the possibility of higher rates of recurrence with prolonged treatment and significant inflammatory changes. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Endoscopic resection of acetabular screw tip to decompress sciatic nerve following total hip arthroplasty.

PubMed

Yoon, Sun-Jung; Park, Myung-Sik; Matsuda, Dean K; Choi, Yun Ho

2018-06-04

Sciatic nerve injuries following total hip arthroplasty are disabling complications. Although degrees of injury are variable from neuropraxia to neurotmesis, mechanical irritation of sciatic nerve might be occurred by protruding hardware. This case shows endoscopic decompression for protruded acetabular screw irritating sciatic nerve, the techniques described herein may permit broader arthroscopic/endoscopic applications for management of complications after reconstructive hip surgery. An 80-year-old man complained of severe pain and paresthesias following acetabular component revision surgery. Physical findings included right buttock pain with radiating pain to lower extremity. Radiographs and computed tomography imaging showed that the sharp end of protruded screw invaded greater sciatic foramen anterior to posterior and distal to proximal direction at sciatic notch level. A protruding tip of the acetabular screw at the sciatic notch was decompressed by use of techniques gained from experience performing endoscopic sciatic nerve decompression. The pre-operative pain and paresthesias resolved post-operatively after recovering from anesthesia. This case report describes the first documented endoscopic resection of the tip of the acetabular screw irritating sciatic nerve after total hip arthroplasty. If endoscopic resection of an offending acetabular screw can be performed in a safe and minimally invasive manner, one can envision a future expansion of the role of hip arthroscopic surgery in several complications management after total hip arthroplasty.

Flow Rate Through Pigtail Catheter Used for Left Heart Decompression in an Artificial Model of Extracorporeal Membrane Oxygenation Circuit.

PubMed

Kim, Won Ho; Hong, Tae Hee; Byun, Joung Hun; Kim, Jong Woo; Kim, Sung Hwan; Moon, Sung Ho; Park, Hyun Oh; Choi, Jun Young; Yang, Jun Ho; Jang, In Seok; Lee, Chung Eun; Yun, Jeong Hee

In refractory cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (ECMO) can be initiated. Although left heart decompression can be accomplished by insertion of a left atrial (LA) or left ventricular (LV) cannula using a percutaneous pigtail catheter, the venting flow rate according to catheter size and ECMO flow rate is unknown. We developed an artificial ECMO circuit. One liter saline bag with its pressure set to 20 mm Hg was connected to ECMO to mimic LV failure. A pigtail catheter was inserted into the 1 L saline bag to simulate LV unloading. For each pigtail catheter size (5-8 Fr) and ECMO flow rate (2.0-4.0 L/min), the moving distance of an air bubble that was injected through a three-way stopcock was measured in the arterial pressure line between the pigtail catheter and ECMO inflow limb. The flow rate was then calculated. We obtained the following equation to estimate the pigtail catheter flow rate.Pigtail vent catheter flow rate (ml/min) = 8×ECMOflow rate(L /min)+9×pigtail catheter size(Fr)- 57This equation would aid in designing of a further study to determine optimal venting flow rate. To achieve optimal venting flow, our equation would enable selection of an adequate catheter size.

Orbital Decompression in Thyroid Eye Disease

PubMed Central

Fichter, N.; Guthoff, R. F.; Schittkowski, M. P.

2012-01-01

Though enlargement of the bony orbit by orbital decompression surgery has been known for about a century, surgical techniques vary all around the world mostly depending on the patient's clinical presentation but also on the institutional habits or the surgeon's skills. Ideally every surgical intervention should be tailored to the patient's specific needs. Therefore the aim of this paper is to review outcomes, hints, trends, and perspectives in orbital decompression surgery in thyroid eye disease regarding different surgical techniques. PMID:24558591

Results of multiple drilling compared with those of conventional methods of core decompression.

PubMed

Song, Won Seok; Yoo, Jeong Joon; Kim, Young-Min; Kim, Hee Joong

2007-01-01

We performed multiple drilling as a femoral head-preserving procedure for osteonecrosis of the femoral head thinking the therapeutic effects of core decompression could be achieved by this simpler procedure than core decompression. We retrospectively reviewed 136 patients (163 hips) who had multiple drilling using 9/64-inch Steinmann pins for treatment of nontraumatic osteonecrosis of the femoral head. The mean followup for patients who did not require additional surgery (113 hips) was 87 months (range, 60-134 months). We defined failure as the need for additional surgery or a Harris hip score less than 75. After a minimum 5-year followup, 79% (31/39) of patients with Stage I disease and 77% (62/81) of patients with Stage II disease had no additional surgery. All (15/15) small lesions (<25% involvement) and 84% (37/44) of medium-sized lesions (25-50% involvement) were considered successful. Survival rates of patients with Ficat Stages I or II lesions were greater than survival rates for patients with Stage III lesions. Hips with a large necrotic area had poor results. We had one instance of subtrochanteric fracture through drill entry holes. Multiple drilling is straightforward with few complications and produces results comparable to results of other core decompression techniques.

Sub-diffraction Imaging via Surface Plasmon Decompression

DTIC Science & Technology

2014-06-08

of the local wavelength of a surface plasmon polariton supported by two adjoining curved metal surfaces. The views, opinions and/or findings...adiabatic decompression of the local wavelength of a surface plasmon polariton supported by two adjoining curved metal surfaces. Conference Name...diffraction imaging based on a process of adiabatic decompression of the local wavelength of a surface plasmon polariton supported by two adjoining curved

Ambulation Increases Decompression Sickness in Altitude Exposure

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Pollock, N. W.; Natoli, M. J.; Wessel, J. H., III; Gernhardt, M. L.

2014-01-01

INTRODUCTION - Exercise accelerates inert gas elimination during oxygen breathing prior to decompression (prebreathe), but may also promote bubble formation and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of exercise are likely critical to the net effect. The NASA Prebreathe Reduction Program (PRP) combined oxygen prebreathe and exercise preceding a 4.3 psi exposure in non-ambulatory subjects (a microgravity analog) to produce two protocols now used by astronauts preparing for extravehicular activity (CEVIS and ISLE). Additional work is required to investigate whether exercise normal to 1 G environments increases the risk of DCS over microgravity simulation. METHODS - The CEVIS protocol was replicated with one exception. Our subjects completed controlled ambulation (walking in place with fixed cadence and step height) during both preflight and at 4.3 psi instead of remaining non-ambulatory throughout. Decompression stress was graded with aural Doppler (Spencer 0-IV scale). Two-dimensional echocardiographic imaging was used to look for left heart gas emboli (the presence of which prompted test termination). Venous blood was collected at three points to correlate Doppler measures of decompression stress with microparticle (cell fragment) accumulation. Fisher Exact Tests compared test and control groups. Trial suspension would occur when DCS risk >15% or grade IV venous gas emboli (VGE) risk >20% (at 70% confidence). RESULTS - Eleven person-trials were completed (9 male, 2 female) when DCS prompted suspension. DCS was greater than in CEVIS trials (3/11 [27%] vs. 0/45 [0%], respectively, p=0.03). Statistical significance was not reached for peak grade IV VGE (2/11 [18%] vs. 3/45 [7%], p=0.149) or cumulative grade IV VGE observations per subject-trial (8/128 [6%] vs. 26/630 [4%], p=0.151). Microparticle data were collected for 5/11 trials (3 with DCS outcomes), with widely varying patterns that could not be resolved statistically

Sagittal imbalance in patients with lumbar spinal stenosis and outcomes after simple decompression surgery.

PubMed

Shin, E Kyung; Kim, Chi Heon; Chung, Chun Kee; Choi, Yunhee; Yim, Dahae; Jung, Whei; Park, Sung Bae; Moon, Jung Hyeon; Heo, Won; Kim, Sung-Mi

2017-02-01

Lumbar spinal stenosis (LSS) is the most common lumbar degenerative disease, and sagittal imbalance is uncommon. Forward-bending posture, which is primarily caused by buckling of the ligamentum flavum, may be improved via simple decompression surgery. The objectives of this study were to identify the risk factors for sagittal imbalance and to describe the outcomes of simple decompression surgery. This is a retrospective nested case-control study PATIENT SAMPLE: This was a retrospective study that included 83 consecutive patients (M:F=46:37; mean age, 68.5±7.7 years) who underwent decompression surgery and a minimum of 12 months of follow-up. The primary end point was normalization of sagittal imbalance after decompression surgery. Sagittal imbalance was defined as a C7 sagittal vertical axis (SVA) ≥40 mm on a 36-inch-long lateral whole spine radiograph. Logistic regression analysis was used to identify the risk factors for sagittal imbalance. Bilateral decompression was performed via a unilateral approach with a tubular retractor. The SVA was measured on serial radiographs performed 1, 3, 6, and 12 months postoperatively. The prognostic factors for sagittal balance recovery were determined based on various clinical and radiological parameters. Sagittal imbalance was observed in 54% (45/83) of patients, and its risk factors were old age and a large mismatch between pelvic incidence and lumbar lordosis. The 1-year normalization rate was 73% after decompression surgery, and the median time to normalization was 1 to 3 months. Patients who did not experience SVA normalization exhibited low thoracic kyphosis (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.02-1.10) (p<.01) and spondylolisthesis (HR, 0.33; 95% CI, 0.17-0.61) before surgery. Sagittal imbalance was observed in more than 50% of LSS patients, but this imbalance was correctable via simple decompression surgery in 70% of patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of Orbital Decompression on Corneal Topography in Patients with Thyroid Ophthalmopathy

PubMed Central

Kim, Su Ah; Jung, Su Kyung; Paik, Ji Sun; Yang, Suk-Woo

2015-01-01

Objective To evaluate changes in corneal astigmatism in patients undergoing orbital decompression surgery. Methods This retrospective, non randomized comparative study involved 42 eyes from 21 patients with thyroid ophthalmopathy who underwent orbital decompression surgery between September 2011 and September 2014. The 42 eyes were divided into three groups: control (9 eyes), two-wall decompression (25 eyes), and three-wall decompression (8 eyes). The control group was defined as the contralateral eyes of nine patients who underwent orbital decompression surgery in only one eye. Corneal topography (Orbscan II), Hertel exophthalmometry, and intraocular pressure were measured at 1 month before and 3 months after surgery. Corneal topographic parameters analyzed were total astigmatism (TA), steepest axis (SA), central corneal thickness (CCT), and anterior chamber depth (ACD). Results Exophthalmometry values and intraocular pressure decreased significantly after the decompression surgery. The change (absolute value (|x|) of the difference) in astigmatism at the 3 mm zone was significantly different between the decompression group and the controls (p = 0.025). There was also a significant change in the steepest axis at the 3 mm zone between the decompression group and the controls (p = 0.033). An analysis of relevant changes in astigmatism showed that there was a dominant tendency for incyclotorsion of the steepest axis in eyes that underwent decompression surgery. Using Astig PLOT, the mean surgically induced astigmatism (SIA) was 0.21±0.88 D with an axis of 46±22°, suggesting that decompression surgery did change the corneal shape and induced incyclotorsion of the steepest axis. Conclusions There was a significant change in corneal astigmatism after orbital decompression surgery and this change was sufficient to affect the optical function of the cornea. Surgeons and patients should be aware of these changes. PMID:26352432

Combined microwave ablation and minimally invasive open decompression for the management of thoracic metastasis in breast cancer.

PubMed

Liu, Bin; Yuan, Zhenchao; Wei, Chang Yuan

2018-01-01

The incidence rate of thoracic metastasis from breast cancer is increasing. Microwave ablation is one type of clinical therapy used to treat metastatic spine disease, although it can cause protein denaturation and immediate cell death, and coagulative necrosis can occur. Minimally invasive open decompression is associated with lower rates of surgical complications in comparison to traditional open surgery. Therefore, it is an alternative therapeutic option for spinal metastases. This study aimed to assess the efficacy of microwave ablation with minimally invasive open decompression in the management of breast cancer patients with thoracic metastasis. This single-institution retrospective study investigated 23 cases of thoracic metastasis from breast cancer treated with combined microwave ablation and minimally invasive open decompression. Patients that presented with indications for surgery underwent surgical treatment. Data were collected for pain scores, the Frankel Grade classification system for acute spinal injury, the Karnofsky performance status (KPS) scale and complications due to treatment. Of the 23 patients included in this study, all were successfully treated with microwave ablation and minimal invasive open decompression using our metrics. Of those, 18 patients (78.3%) showed improvement in their KPS results while 5 (21.7%) had alleviation of KPS. All 23 patients showed improvement in their Frankel Grade, suggesting improved neurological function following surgery. Most of the patients reported pain relief. Postoperative complications occurred in 4 patients. Microwave ablation combined with minimally invasive open decompression therapy for breast cancer patients with thoracic metastatic tumors is an alternative treatment that maintains or improves functional outcome in comparison to open surgery.

Altitude-induced decompression sickness

DOT National Transportation Integrated Search

2010-01-01

Decompression sickness (DCS) describes a condition characterized by a variety of symptoms resulting from exposure to low barometric pressures that cause inert gases (mainly nitrogen), normally dissolved in body fluids and tissues, to come out of phys...

Decompressive craniectomy in diffuse traumatic brain injury.

PubMed

Cooper, D James; Rosenfeld, Jeffrey V; Murray, Lynnette; Arabi, Yaseen M; Davies, Andrew R; D'Urso, Paul; Kossmann, Thomas; Ponsford, Jennie; Seppelt, Ian; Reilly, Peter; Wolfe, Rory

2011-04-21

It is unclear whether decompressive craniectomy improves the functional outcome in patients with severe traumatic brain injury and refractory raised intracranial pressure. From December 2002 through April 2010, we randomly assigned 155 adults with severe diffuse traumatic brain injury and intracranial hypertension that was refractory to first-tier therapies to undergo either bifrontotemporoparietal decompressive craniectomy or standard care. The original primary outcome was an unfavorable outcome (a composite of death, vegetative state, or severe disability), as evaluated on the Extended Glasgow Outcome Scale 6 months after the injury. The final primary outcome was the score on the Extended Glasgow Outcome Scale at 6 months. Patients in the craniectomy group, as compared with those in the standard-care group, had less time with intracranial pressures above the treatment threshold (P<0.001), fewer interventions for increased intracranial pressure (P<0.02 for all comparisons), and fewer days in the intensive care unit (ICU) (P<0.001). However, patients undergoing craniectomy had worse scores on the Extended Glasgow Outcome Scale than those receiving standard care (odds ratio for a worse score in the craniectomy group, 1.84; 95% confidence interval [CI], 1.05 to 3.24; P=0.03) and a greater risk of an unfavorable outcome (odds ratio, 2.21; 95% CI, 1.14 to 4.26; P=0.02). Rates of death at 6 months were similar in the craniectomy group (19%) and the standard-care group (18%). In adults with severe diffuse traumatic brain injury and refractory intracranial hypertension, early bifrontotemporoparietal decompressive craniectomy decreased intracranial pressure and the length of stay in the ICU but was associated with more unfavorable outcomes. (Funded by the National Health and Medical Research Council of Australia and others; DECRA Australian Clinical Trials Registry number, ACTRN012605000009617.).

Spatial domain entertainment audio decompression/compression

NASA Astrophysics Data System (ADS)

Chan, Y. K.; Tam, Ka Him K.

2014-02-01

The ARM7 NEON processor with 128bit SIMD hardware accelerator requires a peak performance of 13.99 Mega Cycles per Second for MP3 stereo entertainment quality decoding. For similar compression bit rate, OGG and AAC is preferred over MP3. The Patent Cooperation Treaty Application dated 28/August/2012 describes an audio decompression scheme producing a sequence of interleaving "min to Max" and "Max to min" rising and falling segments. The number of interior audio samples bound by "min to Max" or "Max to min" can be {0|1|…|N} audio samples. The magnitudes of samples, including the bounding min and Max, are distributed as normalized constants within the 0 and 1 of the bounding magnitudes. The decompressed audio is then a "sequence of static segments" on a frame by frame basis. Some of these frames needed to be post processed to elevate high frequency. The post processing is compression efficiency neutral and the additional decoding complexity is only a small fraction of the overall decoding complexity without the need of extra hardware. Compression efficiency can be speculated as very high as source audio had been decimated and converted to a set of data with only "segment length and corresponding segment magnitude" attributes. The PCT describes how these two attributes are efficiently coded by the PCT innovative coding scheme. The PCT decoding efficiency is obviously very high and decoding latency is basically zero. Both hardware requirement and run time is at least an order of magnitude better than MP3 variants. The side benefit is ultra low power consumption on mobile device. The acid test on how such a simplistic waveform representation can indeed reproduce authentic decompressed quality is benchmarked versus OGG(aoTuv Beta 6.03) by three pair of stereo audio frames and one broadcast like voice audio frame with each frame consisting 2,028 samples at 44,100KHz sampling frequency.

Assessment of two methods of gastric decompression for the initial management of gastric dilatation-volvulus.

PubMed

Goodrich, Z J; Powell, L L; Hulting, K J

2013-02-01

To assess gastric trocarization and orogastric tubing as a means of gastric decompression for the initial management of gastric dilatation-volvulus. Retrospective review of 116 gastric dilatation-volvulus cases from June 2001 to October 2009. Decompression was performed via orogastric tubing in 31 dogs, gastric trocarization in 39 dogs and a combination of both in 46 dogs. Tubing was successful in 59 (75·5%) dogs and unsuccessful in 18 (23·4%) dogs. Trocarization was successful in 73 (86%) dogs and unsuccessful in 12 (14%) dogs. No evidence of gastric perforation was noted at surgery in dogs undergoing either technique. One dog that underwent trocarization had a splenic laceration identified at surgery that did not require treatment. Oesophageal rupture or aspiration pneumonia was not identified in any dog during hospitalization. No statistical difference was found between the method of gastric decompression and gastric compromise requiring surgical intervention or survival to discharge. Orogastric tubing and gastric trocarization are associated with low complication and high success rates. Either technique is an acceptable method for gastric decompression in dogs with gastric dilatation-volvulus. © 2013 British Small Animal Veterinary Association.

46 CFR Appendix A to Part 197 - Air No-Decompression Limits

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives made...

46 CFR Appendix A to Part 197 - Air No-Decompression Limits

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives made...

46 CFR Appendix A to Part 197 - Air No-Decompression Limits

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives made...

46 CFR Appendix A to Part 197 - Air No-Decompression Limits

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives made...

Improved chest recoil using an adhesive glove device for active compression–decompression CPR in a pediatric manikin model☆

PubMed Central

Udassi, Jai P.; Udassi, Sharda; Lamb, Melissa A.; Lamb, Kenneth E.; Theriaque, Douglas W.; Shuster, Jonathan J.; Zaritsky, Arno L.; Haque, Ikram U.

2013-01-01

Objective We developed an adhesive glove device (AGD) to perform ACD-CPR in pediatric manikins, hypothesizing that AGD-ACD-CPR provides better chest decompression compared to standard (S)-CPR. Design Split-plot design randomizing 16 subjects to test four manikin-technique models in a crossover fashion to AGD-ACD-CPR vs. S-CPR. Healthcare providers performed 5 min of CPR with 30:2 compression:ventilation ratio in the four manikin models: (1) adolescent; (2) child two-hand; (3) child one-hand; and (4) infant two-thumb. Methods Modified manikins recorded compression pressure (CP), compression depth (CD) and decompression depth (DD). The AGD consisted of a modified oven mitt with an adjustable strap; a Velcro patch was sewn to the palmer aspect. The counter Velcro patch was bonded to the anterior chest wall. For infant CPR, the thumbs of two oven mitts were stitched together with Velcro. Subjects were asked to actively pull up during decompression. Subjects’ heart rate (HR), respiratory rate (RR) and recovery time (RT) for HR/RR to return to baseline were recorded. Subjects were blinded to data recordings. Data (mean ± SEM) were analyzed using a two-tailed paired t-test. Significance was defined qualitatively as P ≤ 0.05. Results Mean decompression depth difference was significantly greater with AGD-ACD-CPR compared to S-CPR; 38–75% of subjects achieved chest decompression to or beyond baseline. AGD-ACD-CPR provided 6–12% fewer chest compressions/minute than S-CPR group. There was no significant difference in CD, CP, HR, RR and RT within each group comparing both techniques. Conclusion A simple, inexpensive glove device for ACD-CPR improved chest decompression with emphasis on active pull in manikins without excessive rescuer fatigue. The clinical implication of fewer compressions/minute in the AGD group needs to be evaluated. PMID:19683849

Empirical models for use in designing decompression procedures for space operations

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Edwards, Benjamin F.; Waligora, James M.; Horrigan, David J., Jr.

1987-01-01

Empirical models for predicting the incidence of Type 1 altitude decompression sickness (DCS) and venous gas emboli (VGE) during space extravehicular activity (EVA), and for use in designing safe denitrogenation decompression procedures are developed. The models are parameterized using DCS and VGE incidence data from NASA and USAF manned altitude chamber decompression tests using 607 male and female subject tests. These models, and procedures for their use, consist of: (1) an exponential relaxation model and procedure for computing tissue nitrogen partial pressure resulting from a specified prebreathing and stepped decompression sequence; (2) a formula for calculating Tissue Ratio (TR), a tissue decompression stress index; (3) linear and Hill equation models for predicting the total incidence of VGE and DCS attendant with a particular TR; (4) graphs of cumulative DCS and VGE incidence (risk) versus EVA exposure time at any specified TR; and (5) two equations for calculating the average delay period for the initial detection of VGE or indication of Type 1 DCS in a group after a specific denitrogenation decompression procedure. Several examples of realistic EVA preparations are provided.

Decompression to altitude: assumptions, experimental evidence, and future directions.

PubMed

Foster, Philip P; Butler, Bruce D

2009-02-01

Although differences exist, hypobaric and hyperbaric exposures share common physiological, biochemical, and clinical features, and their comparison may provide further insight into the mechanisms of decompression stress. Although altitude decompression illness (DCI) has been experienced by high-altitude Air Force pilots and is common in ground-based experiments simulating decompression profiles of extravehicular activities (EVAs) or astronauts' space walks, no case has been reported during actual EVAs in the non-weight-bearing microgravity environment of orbital space missions. We are uncertain whether gravity influences decompression outcomes via nitrogen tissue washout or via alterations related to skeletal muscle activity. However, robust experimental evidence demonstrated the role of skeletal muscle exercise, activities, and/or movement in bubble formation and DCI occurrence. Dualism of effects of exercise, positive or negative, on bubble formation and DCI is a striking feature in hypobaric exposure. Therefore, the discussion and the structure of this review are centered on those highlighted unresolved topics about the relationship between muscle activity, decompression, and microgravity. This article also provides, in the context of altitude decompression, an overview of the role of denitrogenation, metabolic gases, gas micronuclei, stabilization of bubbles, biochemical pathways activated by bubbles, nitric oxide, oxygen, anthropometric or physiological variables, Doppler-detectable bubbles, and potential arterialization of bubbles. These findings and uncertainties will produce further physiological challenges to solve in order to line up for the programmed human return to the Moon, the preparation for human exploration of Mars, and the EVAs implementation in a non-zero gravity environment.

[Analysis of decompression safety during extravehicular activity of astronauts in the light of probability theory].

PubMed

Nikolaev, V P; Katuntsev, V P

1998-01-01

Objectives of the study were comparative assessment of the risk of decompression sickness (DCS) in human subjects during shirt-sleeve simulation of extravehicular activity (EVA) following Russian and U.S. protocols, and analysis of causes of the difference between real and simulated EVA decompression safety. To this end, DCS risk during exposure to a sing-step decompression was estimated with an original method. According to the method, DCS incidence is determined by distribution of nucleation efficacy index (z) in the worst body tissues and its critical values (zm) as a function of initial nitrogen tension in these tissues and final ambient pressure post decompression. Gaussian distribution of z values was calculated basing on results of the DCS risk evaluation on the U.S. EVA protocol in an unsuited chamber test with various pre-breath procedures (Conkin et al., 1987). Half-time of nitrogen washout from the worst tissues was presumed to be 480 min. Calculated DCS risk during short-sleeve EVA simulation by the Russian and U.S. protocols with identical physical loading made up 19.2% and 23.4%, respectively. Effects of the working spacesuit pressure, spacesuit rigidity, metabolic rates during operations in EVA space suit, transcutaneous nitrogen exchange in the oxygen atmosphere of space suit, microgravity, analgesics, short compression due to spacesuit leak tests on the eye of EVA are discussed. Data of the study illustrate and advocate for high decompression safety of current Russian and U.S. EVA protocols.

Effects of decompressive surgery on prognosis and cognitive deficits in herpes simplex encephalitis.

PubMed

Midi, Ipek; Tuncer, Nese; Midi, Ahmet; Mollahasanoglu, Aynur; Konya, Deniz; Sav, Aydin

2007-01-01

Herpes simplex encephalitis (HSE) is a serious viral infection with a high rate of mortality. The most commonly seen complications are behavioral changes, seizures and memory deficits. We report the case of a 37-year-old man with HSE in the right temporal lobe and a severe midline shift who was treated with acyclovir. The patient underwent anterior temporal lobe resection. Although HSE can cause permanent cognitive deficits, in this case, early surgical intervention minimized any deficit, as determined by detailed neuropsychological examination. Surgical decompression is indicated as early as possible in severe cases. This case report emphasizes the effect of surgical decompression for HSE on cognitive function, which has rarely been mentioned before.

Effects of Decompressive Surgery on Prognosis and Cognitive Deficits in Herpes Simplex Encephalitis

PubMed Central

Midi, Ipek; Tuncer, Nese; Midi, Ahmet; Mollahasanoglu, Aynur; Konya, Deniz; Sav, Aydın

2007-01-01

Herpes simplex encephalitis (HSE) is a serious viral infection with a high rate of mortality. The most commonly seen complications are behavioral changes, seizures and memory deficits. We report the case of a 37-year-old man with HSE in the right temporal lobe and a severe midline shift who was treated with acyclovir. The patient underwent anterior temporal lobe resection. Although HSE can cause permanent cognitive deficits, in this case, early surgical intervention minimized any deficit, as determined by detailed neuropsychological examination. Surgical decompression is indicated as early as possible in severe cases. This case report emphasizes the effect of surgical decompression for HSE on cognitive function, which has rarely been mentioned before. PMID:18430984

Needle Decompression of Tension Pneumothorax Tactical Combat Casualty Care Guideline Recommendations

DTIC Science & Technology

2012-07-06

SUBJECT: Needle Decompression of Tension Pneumothorax Tactical Combat Casualty Care Guideline Recommendations 2012-05 2 demonstrating the...Decompression of Tension Pneumothorax Tactical Combat Casualty Care Guideline Recommendations 2012-05 3 needle may be too short to reliably reach the...at the AAL as the preferred site for needle decompression of a presumed tension pneumothorax . Further, studies evaluating chest wall thickness are

Impact of timing of cranioplasty on hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction.

PubMed

Finger, Tobias; Prinz, Vincent; Schreck, Evelyn; Pinczolits, Alexandra; Bayerl, Simon; Liman, Thomas; Woitzik, Johannes; Vajkoczy, Peter

2017-02-01

Patients with malignant middle cerebral artery infarction frequently develop hydrocephalus after decompressive hemicraniectomy. Hydrocephalus itself and known shunt related complications after ventriculo-peritoneal shunt implantation may negatively impact patientś outcome. Here, we aimed to identify factors associated with the development of hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction. A total of 99 consecutive patients with the diagnosis of large hemispheric infarctions and the indication for decompressive hemicraniectomy were included. We retrospectively evaluated patient characteristics (gender, age and selected preoperative risk factors), stroke characteristics (side, stroke volume and existing mass effect) and surgical characteristics (size of the bone flap, initial complication rate, time to cranioplasty, complication rate following cranioplasty, type of implant, number of revision surgeries and mortality). Frequency of hydrocephalus development was 10% in our cohort. Patients who developed a hydrocephalus had an earlier time point of bone flap reimplantation compared to the control group (no hydrocephalus=164±104days, hydrocephalus=108±52days, p<0.05). Additionally, numbers of revision surgeries after cranioplasty was associated with hydrocephalus with a trend towards significance (p=0.08). Communicating hydrocephalus is frequent in patients with malignant middle cerebral artery infarction after decompressive hemicraniectomy. A later time point of cranioplasty might lead to a lower incidence of required shunting procedures in general as we could show in our patient cohort. Copyright © 2016 Elsevier B.V. All rights reserved.

[Theoretical analysis of recompression-based therapies of decompression illness].

PubMed

Nikolaev, V P; Sokolov, G M; Komarevtsev, V N

2011-01-01

Theoretical analysis is concerned with the benefits of oxygen, air and nitrogen-helium-oxygen recompression schedules used to treat decompression illness in divers. Mathematical modeling of tissue bubbles dynamics during diving shows that one-hour oxygen recompression to 200 kPa does not diminish essentially the size of bubble enclosed in a layer that reduces tenfold the intensity of gas diffusion from bubbles. However, these bubbles dissolve fully in all the body tissues equally after 2-hr. air compression to 800 kPa and ensuing 2-d decompression by the Russian navy tables, and 1.5-hr. N-He-O2 compression to this pressure followed by 5-day decompression. The overriding advantage of the gas mixture recompression is that it obviates the narcotic action of nitrogen at the peak of chamber pressure and does not create dangerous tissue supersaturation and conditions for emergence of large bubbles at the end of decompression.

Decompression-Driven Superconductivity Enhancement in In2 Se3.

PubMed

Ke, Feng; Dong, Haini; Chen, Yabin; Zhang, Jianbo; Liu, Cailong; Zhang, Junkai; Gan, Yuan; Han, Yonghao; Chen, Zhiqiang; Gao, Chunxiao; Wen, Jinsheng; Yang, Wenge; Chen, Xiao-Jia; Struzhkin, Viktor V; Mao, Ho-Kwang; Chen, Bin

2017-09-01

An unexpected superconductivity enhancement is reported in decompressed In 2 Se 3 . The onset of superconductivity in In 2 Se 3 occurs at 41.3 GPa with a critical temperature (T c ) of 3.7 K, peaking at 47.1 GPa. The striking observation shows that this layered chalcogenide remains superconducting in decompression down to 10.7 GPa. More surprisingly, the highest T c that occurs at lower decompression pressures is 8.2 K, a twofold increase in the same crystal structure as in compression. It is found that the evolution of T c is driven by the pressure-induced R-3m to I-43d structural transition and significant softening of phonons and gentle variation of carrier concentration combined in the pressure quench. The novel decompression-induced superconductivity enhancement implies that it is possible to maintain pressure-induced superconductivity at lower or even ambient pressures with better superconducting performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Endoscopic Endonasal Optic Nerve Decompression for Fibrous Dysplasia

PubMed Central

DeKlotz, Timothy R.; Stefko, S. Tonya; Fernandez-Miranda, Juan C.; Gardner, Paul A.; Snyderman, Carl H.; Wang, Eric W.

2016-01-01

Objective To evaluate visual outcomes and potential complications for optic nerve decompression using an endoscopic endonasal approach (EEA) for fibrous dysplasia. Design Retrospective chart review of patients with fibrous dysplasia causing extrinsic compression of the canalicular segment of the optic nerve that underwent an endoscopic endonasal optic nerve decompression at the University of Pittsburgh Medical Center from 2010 to 2013. Main Outcome Measures The primary outcome measure assessed was best-corrected visual acuity (BCVA) with secondary outcomes, including visual field testing, color vision, and complications associated with the intervention. Results A total of four patients and five optic nerves were decompressed via an EEA. All patients were symptomatic preoperatively and had objective findings compatible with compressive optic neuropathy: decreased visual acuity was noted preoperatively in three patients while the remaining patient demonstrated an afferent pupillary defect. BCVA improved in all patients postoperatively. No major complications were identified. Conclusion EEA for optic nerve decompression appears to be a safe and effective treatment for patients with compressive optic neuropathy secondary to fibrous dysplasia. Further studies are required to identify selection criteria for an open versus an endoscopic approach. PMID:28180039

Comparison of Porcine and Bovine Collagen Dural Substitutes in Posterior Fossa Decompression for Chiari I Malformation in Adults.

PubMed

Lee, Christine K; Mokhtari, Tara; Connolly, Ian D; Li, Gordon; Shuer, Lawrence M; Chang, Steven D; Steinberg, Gary K; Hayden Gephart, Melanie

2017-12-01

Posterior fossa decompression surgeries for Chiari malformations are susceptible to postoperative complications such as pseudomeningocele, external cerebrospinal fluid (CSF) leak, and meningitis. Various dural substitutes have been used to improve surgical outcomes. This study examined whether the collagen matrix dural substitute type correlated with the incidence of postoperative complications after posterior fossa decompression in adult patients with Chiari I malformations. A retrospective cohort study was conducted of 81 adult patients who underwent an elective decompressive surgery for treatment of symptomatic Chiari I malformations, with duraplasty involving a dural substitute derived from either bovine or porcine collagen matrix. Demographics and treatment characteristics were correlated with surgical outcomes. A total of 81 patients were included in the study. Compared with bovine dural substitute, porcine dural substitute was associated with a significantly higher risk of pseudomeningocele occurrence (odds ratio, 5.78; 95% confidence interval, 1.65-27.15; P = 0.01) and a higher overall complication rate (odds ratio, 3.70; 95% confidence interval, 1.23-12.71; P = 0.03) by univariate analysis. There was no significant difference in the rate of meningitis, repeat operations, or overall complication rate between the 2 dural substitutes. In addition, estimated blood loss was a significant risk factor for meningitis (P = 0.03). Multivariate analyses again showed that porcine dural substitute was associated with pseudomeningocele occurrence, although the association with higher overall complication rate did not reach significance. Dural substitutes generated from porcine collagen, compared with those from bovine collagen, were associated with a higher likelihood of pseudomeningocele development in adult patients undergoing Chiari I malformation decompression and duraplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

An evaluation of potential decompression hazards in small pressurized aircraft.

DOT National Transportation Integrated Search

1967-06-01

Over 300 decompression tests were conducted to determine potential hazards of ejection or incapacitating or fatal head injuries in small volume pressurized aircraft in the event of sudden decompression following the loss of a window, emergency exit, ...

Crystal Thermoelasticity at Extreme Loading Rates and Pressures: Analysis of Higher-Order Energy Potentials

DTIC Science & Technology

2015-07-01

ARL-RP-0526 ● JULY 2015 US Army Research Laboratory Crystal Thermoelasticity at Extreme Loading Rates and Pressures : Analysis of...ARL-RP-0526 ● JULY 2015 US Army Research Laboratory Crystal Thermoelasticity at Extreme Loading Rates and Pressures : Analysis of...2015 4. TITLE AND SUBTITLE Crystal Thermoelasticity at Extreme Loading Rates and Pressures : Analysis of Higher-Order Energy Potentials 5a. CONTRACT

Decompressing recompression chamber attendants during Australian submarine rescue operations.

PubMed

Reid, Michael P; Fock, Andrew; Doolette, David J

2017-09-01

Inside chamber attendants rescuing survivors from a pressurised, distressed submarine may themselves accumulate a decompression obligation which may exceed the limits of Defense and Civil Institute of Environmental Medicine tables presently used by the Royal Australian Navy. This study assessed the probability of decompression sickness (P DCS ) for medical attendants supervising survivors undergoing oxygen-accelerated saturation decompression according to the National Oceanic and Atmospheric Administration (NOAA) 17.11 table. Estimated probability of decompression sickness (P DCS ), the units pulmonary oxygen toxicity dose (UPTD) and the volume of oxygen required were calculated for attendants breathing air during the NOAA table compared with the introduction of various periods of oxygen breathing. The P DCS in medical attendants breathing air whilst supervising survivors receiving NOAA decompression is up to 4.5%. For the longest predicted profile (830 minutes at 253 kPa) oxygen breathing at 30, 60 and 90 minutes at 132 kPa partial pressure of oxygen reduced the air-breathing-associated P DCS to less than 3.1 %, 2.1% and 1.4% respectively. The probability of at least one incident of DCS among attendants, with consequent strain on resources, is high if attendants breathe air throughout their exposure. The introduction of 90 minutes of oxygen breathing greatly reduces the probability of this interruption to rescue operations.

Evaluation of safety of hypobaric decompressions and EVA from positions of probabilistic theory

NASA Astrophysics Data System (ADS)

Nikolaev, V. P.

Formation and subsequent evolution of gas bubbles in blood and tissues of subjects exposed to decompression are casual processes in their nature. Such character of bubbling processes in a body predetermines probabilistic character of decompression sickness (DCS) incidence in divers, aviators and astronauts. Our original probabilistic theory of decompression safety is based on stochastic models of these processes and on the concept of critical volume of a free gas phase in body tissues. From positions of this theory, the probability of DCS incidence during single-stage decompressions and during hypobaric decompressions under EVA in particular, is defined by the distribution of possible values of nucleation efficiency in "pain" tissues and by its critical significance depended on the parameters of a concrete decompression. In the present study the following is shown: 1) the dimensionless index of critical nucleation efficiency for "pain" body tissues is a more adequate index of decompression stress in comparison with Tissue Ratio, TR; 2) a priory the decompression under EVA performed according to the Russian protocol is more safe than decompression under EVA performed in accordance with the U.S. protocol; 3) the Russian space suit operated at a higher pressure and having a higher "rigidity" induces a stronger inhibition of mechanisms of cavitation and gas bubbles formation in tissues of a subject located in it, and by that provides a more considerable reduction of the DCS risk during real EVA performance.

Influence of long-term intermittent exposures to hypoxia on decompression-induced pulmonary haemorrhage.

PubMed Central

Fang, H S; Chen, C F

1976-01-01

Healthy male rats were acclimatized by being placed in a decompression chamber at a simulated altitude of 18 000 feet (5486 m) for three hours daily for 84 days. The altitude acclimatized rats paired with unacclimatized rats were rapidly decompressed together. The range of decompression was performed from on atmospheric pressure to an ambient pressure of 30 mmHg in 0-2 seconds. It was found that in control rats, 14 of 20 lung (70%) exhibited pulmonary haemorrhage following rapid decompression. In altitude acclimatized rats, however, only 6 of 20 (30%) revealed decompression-induced haemorrhage. The difference was statistically significant. The present findings indicate that long-term intermittent exposures to hypoxia might increase the resistance of pulmonary tissue to rapid decompression, resulting in a decrease in frequency and severity of pulmonary haemorrhage. The possible mechanism of such a phenomenon is discussed. PMID:1257942

Evidence Report: Risk of Decompression Sickness (DCS)

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Norcross, Jason R.; Wessel, James H. III; Abercromby, Andrew F. J.; Klein, Jill S.; Dervay, Joseph P.; Gernhardt, Michael L.

2013-01-01

The Risk of Decompression Sickness (DCS) is identified by the NASA Human Research Program (HRP) as a recognized risk to human health and performance in space, as defined in the HRP Program Requirements Document (PRD). This Evidence Report provides a summary of the evidence that has been used to identify and characterize this risk. Given that tissue inert gas partial pressure is often greater than ambient pressure during phases of a mission, primarily during extravehicular activity (EVA), there is a possibility that decompression sickness may occur.

Plants survive rapid decompression: Implications for bioregenerative life support

NASA Astrophysics Data System (ADS)

Wheeler, R. M.; Wehkamp, C. A.; Stasiak, M. A.; Dixon, M. A.; Rygalov, V. Y.

2011-05-01

Radish (Raphanus sativus), lettuce (Latuca sativa), and wheat (Triticum aestivum) plants were grown at either 98 kPa (ambient) or 33 kPa atmospheric pressure with constant 21 kPa oxygen and 0.12 kPa carbon dioxide in atmospherically closed pressure chambers. All plants were grown rockwool using recirculating hydroponics with a complete nutrient solution. At 20 days after planting, chamber pressures were pumped down as rapidly as possible, reaching 5 kPa after about 5 min and ˜1.5 kPa after about 10 min. The plants were held at 1.5 kPa for 30 min and then pressures were restored to their original settings. Temperature (22 °C) and humidity (65% RH) controls were engaged throughout the depressurization, although temperatures dropped to near 16 °C for a brief period. CO2 and O2 were not detectable at the low pressure, suggesting that most of the 1.5 kPa atmosphere consisted of water vapor. Following re-pressurization, plants were grown for another 7 days at the original pressures and then harvested. The lettuce, radish, and wheat plants showed no visible effects from the rapid decompression, and there were no differences in fresh or dry mass when compared to control plants maintained continuously at 33 or 98 kPa. But radish storage root fresh mass and lettuce head fresh and dry masses were less at 33 kPa compared to 98 kPa for both the controls and decompression treatment. The results suggest that plants are extremely resilient to rapid decompression, provided they do not freeze (from evaporative cooling) or desiccate. The water of the hydroponic system was below the boiling pressure during these tests and this may have protected the plants by preventing pressures from dropping below 1.5 kPa and maintaining humidity near 1.5 kPa. Further testing is needed to determine how long plants can withstand such low pressure, but the results suggest there are at least 30 min to respond to catastrophic pressure losses in a plant production chamber that might be used for life

Role of Inflammatory Reponse in Experimental Decompression Sickness

NASA Technical Reports Server (NTRS)

Butler, B. D.; Little, T.

1999-01-01

Decompression to altitude can result in gas bubble formation both in tissues and in the systemic veins. The venous gas emboli (VGE) are often monitored during decompression exposures to assess risk for decompression sickness (DCS). Astronauts are at risk for DCS during extravehicular activities (EVA), where decompression occurs from the Space Shuttle or Space Station atmospheric pressure of 14.7 pounds per square inch (PSI) to that of the space suit pressure of 4.3 PSI. DCS symptoms include diffuse pain, especially around joints, inflammation and edema. Pathophysiological effects include interstitial inflammatory responses and recurring injury to the vascular endothelium. Such responses can result in vasoconstriction and associated hemodynamic changes.The granulocyte cell activation and chemotaxin release results in the formation of vasoactive and microvascular permeability altering mediators, especially from the lungs which are the principal target organ for the venous bubbles, and from activated cells (neutrophils, platelets, macrophages). Such mediators include free arachidonic acid and the byproducts of its metabolism via the cyclooxygenase and lipoxygenase pathways (see figure). The cyclooxygenase pathway results in formation of prostacyclin and other prostaglandins and thromboxanes that cause vasoconstriction, bronchoconstriction and platelet aggregation. Leukotrienes produced by the alternate pathway cause pulmonary and bronchial smooth muscle contraction and edema. Substances directly affecting vascular tone such as nitric oxide may also play a role in the respose to DCS. We are studying the role and consequent effects of the release inflammatory bioactive mediators as a result of DCS and VGE. More recent efforts are focused on identifying the effects of the body's circadian rhythm on these physiological consequences to decompression stress. al

Are Locked Facets a Contraindication for Extreme Lateral Interbody Fusion?

PubMed

Navarro-Ramirez, Rodrigo; Lang, Gernot; Moriguchi, Yu; Elowitz, Eric; Corredor, Jose Alfredo; Avila, Mauricio J; Gotfryd, Alberto; Alimi, Marjan; Gandevia, Lena; Härtl, Roger

2017-04-01

Extreme lateral interbody fusion (ELIF) has gained popularity as a minimally invasive treatment allowing for indirect decompression of neural elements. However, evidence regarding the influence of facet degeneration (FD) and facet tropism (FT) toward indirect decompression is lacking. The aim of the study was to evaluate whether indirect decompression is impaired by FD and FT in patients undergoing ELIF. Thirty-seven patients undergoing ELIF were included in a retrospective study. Radiographic parameters including disk height, segmental disk angle, foraminal area, FD, FT, and clinical outcome parameters (Oswestry Disability Index and Visual Analog Scale) were measured preoperatively and postoperatively. FD and FT were correlated with radiographic and clinical outcome parameters in order to determine predictors restricting indirect decompression. Thirty-seven patients with a total of 74 levels were analyzed. Clinical and radiographic outcome measures including central canal area (Δ = +17.2 mm 2 ), mean disk height (Δ = +3 mm), and foraminal area (Δ = +9.9 mm 2 ) revealed significant improvement compared with before surgery (P ≤ 0.05). Patients with severe FD (grade 4) were more likely to have FT ≥ 12 degrees (32.3%) than patients without/mild (grades 0 and 1; 10%) or moderate FD (grades 2 and 3; 13%), P ≤ 0.05. FD and FT did not affect disk height restoration, foraminal area, canal surface area, or clinical outcome measures (P ≥ 0.05). Indirect decompression of neural elements in ELIF is not impaired by FD and FT are not relative contraindications in patients undergoing ELIF. Copyright © 2016. Published by Elsevier Inc.

Arthroscopic-assisted core decompression of the humeral head.

PubMed

Dines, Joshua S; Strauss, Eric J; Fealy, Stephen; Craig, Edward V

2007-01-01

Humeral head osteonecrosis is a progressive disease that requires prompt diagnosis and treatment. Core decompression is a viable treatment option for early-stage cases. Most surgeons perform core decompression by arthroscopically visualizing the necrotic area of bone and using a cannulated drill to take a core. Several attempts are frequently needed to reach the proper location. In the hip multiple passes are associated with complications. We describe the use of an anterior cruciate ligament (ACL) tibial drill guide to precisely localize the area of necrotic bone. Diagnostic arthroscopy is performed to assess the areas of osteonecrosis. Core decompression is performed by use of an ACL tibial guide, brought in through the anterior or posterior portal to precisely localize the necrotic area in preparation for drilling. Under image intensification, Steinmann pins are advanced into the area of osteonecrosis. Once positioned, several 4-mm cores are made. We treated 3 patients with this technique, and all had immediate pain relief. The use of the ACL guide allows precise localization of the area of humeral head involvement and avoids multiple drillings into unaffected areas. Initial indications are that arthroscopic-assisted core decompression with an ACL guide is an effective alternative to previously used methods.

European EVA decompression sickness risks

NASA Astrophysics Data System (ADS)

Vogt, Lorenz; Wenzel, Jürgen; Skoog, A. I.; Luck, S.; Svensson, Bengt

For the first manned flight of Hermes there will be a capability of performing EVA. The European EVA Space Suit will be an anthropomorphic system with an internal pressure of 500 hPa of pure oxygen. The pressure reduction from the Hermes cabin pressure of 1013 hPa will induce a risk for Decompression Sickness (DCS) for the EVA crewmember if no adequate protective procedures are implemented. Specific decompression procedures have to be developed. From a critical review of the literature and by using knowledge gained from research conducted in the past in the fields of diving and aerospace medicine safe protective procedures are proposed for the European EVA scenario. An R factor of 1.2 and a tissue half-time ( t1/2) of 360 minutes in a single-tissue model have been identified as appropriate operational values. On the basis of an acceptable risk level of approximately 1%, oxygen prebreathing times are proposed for (a) direct pressure reduction from 1013 hPa to a suit pressure of 500 hPa, and (b) staged decompression using a 700 hPa intermediate stage in the spacecraft cabin. In addition, factors which influence individual susceptibility to DCS are identified. Recommendations are also given in the areas of crew selection and medical monitoring requirements together with therapeutic measures that can be implemented in the Hermes scenario. A method for demonstration of the validity of proposed risks and procedures is proposed.

Micro-surgical decompression for greater occipital neuralgia.

PubMed

Li, Fuyong; Ma, Yi; Zou, Jianjun; Li, Yanfeng; Wang, Bin; Huang, Haitao; Wang, Quancai; Li, Liang

2012-01-01

To evaluate the clinical effect of micro-surgical decompression of greater occipital nerve for greater occipital neuralgia (GON). 76 patients underwent surgical decompression of the great occipital nerve. A nerve block was tested before operation. The headache rapidly resolved after infiltration of 1% Lidocaine near the tender area of the nerve trunk. 89 procedures were performed for 76 patients. The mean follow up duration was 20 months (range 7-52 months). The headache symptoms of 68 (89.5%) patients were completely resolved, and another 5 (6.6%) patients were significantly relieved without the need for any further medical treatment. Three (3.9%) patients experienced recurrence of the disorder. All patients experienced hypoesthesia of the innervated area of the great occipital nerve. They recovered gradually within 1 to 6 months after surgery. Micro-surgical decompression of the greater occipital nerve is a safe and effective method for greater occipital neuralgia. We believe our findings support the notion that the technique should also be considered as the first-line procedure for GON.

Intraoperative Computed Tomography for Cervicomedullary Decompression of Foramen Magnum Stenosis in Achondroplasia: Two Case Reports

PubMed Central

Arishima, Hidetaka; Tsunetoshi, Kenzo; Kodera, Toshiaki; Kitai, Ryuhei; Takeuchi, Hiroaki; Kikuta, Ken-ichiro

2013-01-01

The authors report two cases of cervicomedullary decompression of foramen magnum (FM) stenosis in children with achondroplasia using intraoperative computed tomography (iCT). A 14-month-old girl with myelopathy and retarded motor development, and a 10-year-old girl who had already undergone incomplete FM decompression was presented with myelopathy. Both patients underwent decompressive sub-occipitalcraniectomy and C1 laminectomy without duraplasty using iCT. It clearly showed the extent of FM decompression during surgery, which finally enabled sufficient decompression. After the operation, their myelopathy improved. We think that iCT can provide useful information and guidance for sufficient decompression for FM stenosis in children with achondroplasia. PMID:24140778

Intraoperative computed tomography for cervicomedullary decompression of foramen magnum stenosis in achondroplasia: two case reports.

PubMed

Arishima, Hidetaka; Tsunetoshi, Kenzo; Kodera, Toshiaki; Kitai, Ryuhei; Takeuchi, Hiroaki; Kikuta, Ken-Ichiro

2013-01-01

The authors report two cases of cervicomedullary decompression of foramen magnum (FM) stenosis in children with achondroplasia using intraoperative computed tomography (iCT). A 14-month-old girl with myelopathy and retarded motor development, and a 10-year-old girl who had already undergone incomplete FM decompression was presented with myelopathy. Both patients underwent decompressive sub-occipitalcraniectomy and C1 laminectomy without duraplasty using iCT. It clearly showed the extent of FM decompression during surgery, which finally enabled sufficient decompression. After the operation, their myelopathy improved. We think that iCT can provide useful information and guidance for sufficient decompression for FM stenosis in children with achondroplasia.

Elective decompression of the left ventricle in pediatric patients may reduce the duration of venoarterial extracorporeal membrane oxygenation.

PubMed

Hacking, Douglas F; Best, Derek; d'Udekem, Yves; Brizard, Christian P; Konstantinov, Igor E; Millar, Johnny; Butt, Warwick

2015-04-01

We aimed to determine the effect of elective left heart decompression at the time of initiation of central venoarterial extracorporeal membrane oxygenation (VA ECMO) on VA ECMO duration and clinical outcomes in children in a single tertiary ECMO referral center with a large pediatric population from a national referral center for pediatric cardiac surgery. We studied 51 episodes of VA ECMO in a historical cohort of 49 pediatric patients treated between the years 1990 and 2013 in the Paediatric Intensive Care Unit (PICU) of the Royal Children's Hospital, Melbourne. The cases had a variety of diagnoses including congenital cardiac abnormalities, sepsis, myocarditis, and cardiomyopathy. Left heart decompression as an elective treatment or an emergency intervention for left heart distension was effectively achieved by a number of methods, including left atrial venting, blade atrial septostomy, and left ventricular cannulation. Elective left heart decompression was associated with a reduction in time on ECMO (128 h) when compared with emergency decompression (236 h) (P = 0.013). Subgroup analysis showed that ECMO duration was greatest in noncardiac patients (elective 138 h, emergency 295 h; P = 0.02) and in patients who died despite both emergency decompression and ECMO (elective 133 h, emergency 354 h; P = 0.002). As the emergency cases had a lower pH, a higher PaCO2 , and a lower oxygenation index and were treated with a higher mean airway pressure, positive end-expiratory pressure, and respiratory rate prior to receiving VA ECMO, we undertook multivariate linear regression modeling to show that only PaCO2 and the timing of left heart decompression were associated with ECMO duration. However, elective left heart decompression was not associated with a reduction in length of PICU stay, duration of mechanical ventilation, or duration of oxygen therapy. Elective left heart decompression was not associated with improved ECMO survival or survival to PICU discharge

Type II decompression sickness in a hyperbaric inside attendant.

PubMed

Johnson-Arbor, Kelly

2012-01-01

Decompression sickness (DCS) of an inside attendant (IA) is rarely encountered in hyperbarics. This report describes an IA who developed Type II DCS after a routine hyperbaric exposure. A 50-year-old male complained of lower extremity weakness and paresthesias after serving as an IA during a hyperbaric treatment to 40 fsw (122.52 kPa). Within 10 minutes after the conclusion of the treatment, the IA experienced irritability and confusion, and was unable to walk. Physical examination revealed decreased sensation below the T7 level, and decreased strength in the lower extremities. Type II DCS was diagnosed, and the IA was recompressed to 60 fsw (183.78 kPa) on a U.S. Navy Treatment Table 6, which resulted in improvement of his symptoms. Transthoracic echocardiography with bubble study performed 16 months after the event demonstrated a large patent foramen ovale (PFO). Increased age, decreased physical fitness and the undiagnosed PFO may have predisposed this attendant to developing DCS. Although rare, DCS may occur in IAs. Routine monitoring and reporting of the long-term health of hyperbaric IAs should be considered by hyperbaric facilities and medical directors in order to further understand the characteristics of DCS and other hyperbaric-related conditions in these workers.

Decompressive craniectomy and hydrocephalus: proposal of a therapeutic flow chart.

PubMed

Peraio, Simone; Calcagni, Maria Lucia; Mattoli, Maria Vittoria; Marziali, Giammaria; DE Bonis, Pasquale; Pompucci, Angelo; Anile, Carmelo; Mangiola, Annunziato

2017-12-01

Decompressive craniectomy (DC) may be necessary to save the lives of patients suffering from intracranial hypertension. However, this procedure is not complication-free. Its two main complications are hydrocephalus and the sinking skin-flap syndrome (SSFS). The radiological findings and the clinical evaluation may be not enough to decide when and/or how to treat hydrocephalus in a decompressed patient. SSFS and hydrocephalus may be not unrelated. In fact, a patient affected by hydrocephalus, after the ventriculo-peritoneal shunt, can develop SSFS; on the other hand, SSFS per se can cause hydrocephalus. Treating hydrocephalus in decompressed patients can be challenging. Radiological findings and clinical evaluation may not be enough to define the most appropriate therapeutic strategy. Cerebrospinal fluid (CSF) dynamics and metabolic evaluations can represent important diagnostic tools for assessing the need of a CSF shunt in patients with a poor baseline neurologic status. Based on our experience, we propose a flow chart for treating decompressed patients affected by ventriculomegaly.

Prevention of decompression sickness during extravehicular activity in space: a review.

PubMed

Tokumaru, O

1997-12-01

Extended and more frequent extravehicular activity (EVA) is planned in NASA's future space programs. The more EVAs are conducted, the higher the incidence of decompression sickness (DCS) that is anticipated. Since Japan is also promoting the Space Station Freedom project with NASA, DCS during EVA will be an inevitable complication. The author reviewed the pathophysiology of DCS and detailed four possible ways of preventing decompression sickness during EVA in space: (1) higher pressure suit technology; (2) preoxygenation/prebreathing; (3) staged decompression; and (4) habitat or vehicle pressurization. Among these measures, development of zero-prebreathe higher pressure suit technology seems most ideal, but because of economic and technical reasons and in cases of emergency, other methods must also be improved. Unsolved problems like repeated decompression or oxygen toxicity were also listed.

Biomechanical analysis of the upper thoracic spine after decompressive procedures.

PubMed

Healy, Andrew T; Lubelski, Daniel; Mageswaran, Prasath; Bhowmick, Deb A; Bartsch, Adam J; Benzel, Edward C; Mroz, Thomas E

2014-06-01

Decompressive procedures such as laminectomy, facetectomy, and costotransversectomy are routinely performed for various pathologies in the thoracic spine. The thoracic spine is unique, in part, because of the sternocostovertebral articulations that provide additional strength to the region relative to the cervical and lumbar spines. During decompressive surgeries, stability is compromised at a presently unknown point. To evaluate thoracic spinal stability after common surgical decompressive procedures in thoracic spines with intact sternocostovertebral articulations. Biomechanical cadaveric study. Fresh-frozen human cadaveric spine specimens with intact rib cages, C7-L1 (n=9), were used. An industrial robot tested all spines in axial rotation (AR), lateral bending (LB), and flexion-extension (FE) by applying pure moments (±5 Nm). The specimens were first tested in their intact state and then tested after each of the following sequential surgical decompressive procedures at T4-T5 consisting of laminectomy; unilateral facetectomy; unilateral costotransversectomy, and subsequently instrumented fusion from T3-T7. We found that in all three planes of motion, the sequential decompressive procedures caused no statistically significant change in motion between T3-T7 or T1-T12 when compared with intact. In comparing between intact and instrumented specimens, our study found that instrumentation reduced global range of motion (ROM) between T1-T12 by 16.3% (p=.001), 12% (p=.002), and 18.4% (p=.0004) for AR, FE, and LB, respectively. Age showed a negative correlation with motion in FE (r = -0.78, p=.01) and AR (r=-0.7, p=.04). Thoracic spine stability was not significantly affected by sequential decompressive procedures in thoracic segments at the level of the true ribs in all three planes of motion in intact thoracic specimens. Age appeared to negatively correlate with ROM of the specimen. Our study suggests that thoracic spinal stability is maintained immediately after

Frequency of decompression illness among recent and extinct mammals and "reptiles": a review

NASA Astrophysics Data System (ADS)

Carlsen, Agnete Weinreich

2017-08-01

The frequency of decompression illness was high among the extinct marine "reptiles" and very low among the marine mammals. Signs of decompression illness are still found among turtles but whales and seals are unaffected. In humans, the risk of decompression illness is five times increased in individuals with Patent Foramen Ovale; this condition allows blood shunting from the venous circuit to the systemic circuit. This right-left shunt is characteristic of the "reptile" heart, and it is suggested that this could contribute to the high frequency of decompression illness in the extinct reptiles.

Frequency of decompression illness among recent and extinct mammals and "reptiles": a review.

PubMed

Carlsen, Agnete Weinreich

2017-08-01

The frequency of decompression illness was high among the extinct marine "reptiles" and very low among the marine mammals. Signs of decompression illness are still found among turtles but whales and seals are unaffected. In humans, the risk of decompression illness is five times increased in individuals with Patent Foramen Ovale; this condition allows blood shunting from the venous circuit to the systemic circuit. This right-left shunt is characteristic of the "reptile" heart, and it is suggested that this could contribute to the high frequency of decompression illness in the extinct reptiles.

Favourable outcome of posterior decompression and stabilization in lordosis for cervical spondylotic myelopathy: the spinal cord "back shift" concept.

PubMed

Denaro, Vincenzo; Longo, Umile Giuseppe; Berton, Alessandra; Salvatore, Giuseppe; Denaro, Luca

2015-11-01

Surgical management of patients with multilevel CSM aims to decompress the spinal cord and restore the normal sagittal alignment. The literature lacks of high level evidences about the best surgical approach. Posterior decompression and stabilization in lordosis allows spinal cord back shift, leading to indirect decompression of the anterior spinal cord. The purpose of this study was to investigate the efficacy of posterior decompression and stabilization in lordosis for multilevel CSM. 36 out of 40 patients were clinically assessed at a mean follow-up of 5, 7 years. Outcome measures included EMS, mJOA Score, NDI and SF-12. Patients were asked whether surgery met their expectations and if they would undergo the same surgery again. Bone graft fusion, instrumental failure and cervical curvature were evaluated. Spinal cord back shift was measured and correlation with EMS and mJOA score recovery rate was analyzed. All scores showed a significative improvement (p < 0.001), except the SF12-MCS (p > 0.05). Ninety percent of patients would undergo the same surgery again. There was no deterioration of the cervical alignment, posterior grafted bones had completely fused and there were no instrument failures. The mean spinal cord back shift was 3.9 mm (range 2.5-4.5 mm). EMS and mJOA recovery rates were significantly correlated with the postoperative posterior cord migration (P < 0.05). Posterior decompression and stabilization in lordosis is a valuable procedure for patients affected by multilevel CSM, leading to significant clinical improvement thanks to the spinal cord back shift. Postoperative lordotic alignment of the cervical spine is a key factor for successful treatment.

[Theoretical evaluation of the risk of decompression illness during simulated extravehicular activity].

PubMed

Nikolaev, V P

2008-01-01

Theoretical analysis of the risk of decompression illness (DI) during extravehicular activity following the Russian and NASA decompression protocols (D-R and D-US, respectively) was performed. In contrast to the tradition approach to decompression stress evaluation by the factor of tissue supersaturation with nitrogen, our probabilistic theory of decompression safety provides a completely reasoned evaluation and comparison of the levels of hazard of these decompression protocols. According to this theory, the function of cumulative DI risk is equal to the sum of functions of cumulative risk of lesion of all body tissues by gas bubbles and their supersaturation by solute gases. Based on modeling of dynamics of these functions, growth of the DI cumulative risk in the course of D-R and D-US follows essentially similar trajectories within the time-frame of up to 330 minutes. However, further extension of D-US but not D-R raises the risk of DI drastically.

Change of Lumbar Ligamentum Flavum after Indirect Decompression Using Anterior Lumbar Interbody Fusion.

PubMed

Ohtori, Seiji; Orita, Sumihisa; Yamauchi, Kazuyo; Eguchi, Yawara; Aoki, Yasuchika; Nakamura, Junichi; Miyagi, Masayuki; Suzuki, Miyako; Kubota, Gou; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Shiga, Yasuhiro; Abe, Koki; Kanamoto, Hiroto; Inoue, Gen; Takahashi, Kazuhisa; Furuya, Takeo; Koda, Masao

2017-02-01

Retrospective case series. The purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up. Extreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported. We evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1-2 to L5-S1 was calculated using a Picture Archiving and Communication System. Spinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1-2 to L5-S1 were 150 mm 2 and 78 mm 2 , respectively. The average CSA of the ligamentum flavum at L4-5 (30 mm 2 ) (fusion level) was significantly less than that at L1-2 to L3-4 or L5-S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4-5 was significantly larger than at the other levels. Spinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery.

[Two-wall decompression without resection of the medial wall. Effect on squint angle].

PubMed

Bertelmann, E; Rüther, K

2011-11-01

Postoperative new onset diplopia can be a disadvantage for surgical orbital decompression in patients with exophthalmos in thyroid eye disease. The various modifications of decompression (number and combination of walls) differ in their influence on the postoperative squint angle. We report on postoperative diplopia in a modified 2 wall decompression strategy (lateral wall and floor). This study was a retrospective analysis of 36 consecutive 2-wall decompressions performed between 2006-2010 in 24 patients with 6 months of stable exophthalmos in thyroid eye disease after medical therapy and radiotherapy. The preoperative and postoperative squint angle in prism cover test (PCT), motility, induction of diplopia, reduction of exophthalmos, visual acuity and complications were evaluated. In all 36 decompressions the postoperative squint angle was equal to or less than before surgery. In 8 eyes additional squint surgery was performed. The mean reduction in exopthalmos was 4.3 mm. An adverse effect of decompression on the postoperative squint angle was not evident in this study. New induction of diplopia was not observed at all. One possible explanation is the preservation of the medial wall.

[Homogeneous spinal-shortening axial decompression procedure for tethered cord syndrome].

PubMed

Wang, Haibo; Sun, Jingchuan; Wang, Yuan; Wu, Zhao; Xu, Tao; Chen, Kefu; Shi, Guodong; Yuan, Wen; Jia, Lianshun; Shi, Jiangang

2015-06-16

Surgical detethering is a traditional treatment for symptomatic tethered cord syndrome. However, such complications as cerebrospinal fluid leakage and neurologic deterioration are common. Homogeneous spinal-shortening axial decompression (HSAD) is a modified procedure of monosegmental spinal-shortening osteotomy and it is a novel surgical alternative of reducing neural tension indirectly. The objective was to evaluate the surgical outcomes of HSAD for tethered cord syndrome. The surgical outcomes were examined for 15 consecutive patients with tethered cord syndrome undergoing HSAD from April 2010 to July 2014. Improvements of neurological symptoms including urinary dysfunction, lower-extremity motor and sensory disturbances and/or gait abnormalities, low-back and/or lower-extremity pain, bowel incontinence and sexual dysfunction were evaluated. Their average follow-up period was 21.5 months. The length of spinal column shortening was 17.2 ± 2.9 mm. Urinary dysfunction (n = 9) was the most common residual deficit. All 9 patients with urological symptoms reported improvements, although deficits persisted at the last follow-up. All patients with lower-extremity motor dysfunction improved and 4 (50.0%) noted complete resolution of preoperative lower-extremity sensory symptoms. All patients reported immediate low-back or lower-extremity pain relief after HSAD. One patient reported improved sexual functioning and regained complete erectile capabilities. Two patients (11%) experienced less satisfactory symptomatic or functional benefit from HSAD. However, the main objective of surgery was to prevent further worsening of neurological status. Complete bone union at osteotomy site was noted in all cases at the last follow-up. As a novel surgical option for tethered cord syndrome, HSAD may avoid such complications as cerebrospinal fluid leakage or neurologic deterioration commonly encountered during traditional detethering surgery. All patients gain satisfactory functional

Decompression sickness in simulated Apollo-Soyuz space missions

NASA Technical Reports Server (NTRS)

Cooke, J. P.; Robertson, W. G.

1974-01-01

Apollo-Soyuz docking module atmospheres were evaluated for incidence of decompression sickness in men simulating passage from the Russian spacecraft atmosphere, to the U.S. spacecraft atmosphere, and then to the American space suit pressure. Following 8 hr of 'shirtsleeve' exposure to 31:69::O2:N2 gas breathing mixture, at 10 psia, subjects were 'denitrogenated' for either 30 or 60 min with 100% O2 prior to decompression directly to 3.7 psia suit equivalent while performing exercise at fixed intervals. Five of 21 subjects experienced symptoms of decompression sickness after 60 min of denitrogenation compared to 6 among 20 subjects after 30 min of denitrogenation. A condition of Grade I bends was reported after 60 min of denitrogenation, and 3 of these 5 subjects noted the disappearance of all symptoms of bends at 3.7 psia. After 30 min of denitrogenation, 2 out of 6 subjects developed Grade II bends at 3.7 psia.

Effect of Inert Gas Switching at Depth on Decompression Outcome in Rats

DTIC Science & Technology

1989-01-01

Indcuae Security Classification) Effect Of inert gas switching at depth on decompression outcome in rats Liil RVRcCall1urn M~E 16. SUPPLEMENTARY...CLASSIrICATrIONOF TI PAGE All other edition% -ate obsfee UNCLASSIFIED Effect of inert gas switching at depth on decompression outcome in rats R. S... Effect of inert gas Although various models of inert gas transport in the switching at depth on decompression outcome in rats. J. Appl

Identifying the Subtle Presentation of Decompression Sickness.

PubMed

Alea, Kenneth

2015-12-01

Decompression sickness is an inherent occupational hazard that has the possibility to leave its victims with significant long-lasting effects that can potentially impact an aircrew's flight status. The relative infrequency of this hazard within the military flying community along with the potentially subtle presentation of decompression sickness (DCS) has the potential to result in delayed diagnosis and treatment, leading to residual deficits that can impact a patient's daily life or even lead to death. The patient presented in this work was diagnosed with a Type II DCS 21 h after a cabin decompression at 35,000 ft (10,668 m). The patient had been asymptomatic with a completely normal physical/neurological exam following his flight. The following day, he presented with excessive fatigue and on re-evaluation was recommended for hyperbaric therapy, during which his symptoms completely resolved. He was re-evaluated 14 d later and cleared to resume flight duties without further incident. The manifestation of this patient's decompression sickness was subtle and followed an evaluation that failed to identify any focal findings. A high index of suspicion with strict follow-up contributed to the identification of DCS in this case, resulting in definitive treatment and resolution of the patient's symptoms. Determination of the need for hyperbaric therapy following oxygen supplementation and a thorough history and physical is imperative. If the diagnosis is in question, consider preemptive hyperbaric therapy as the benefits of treatment in DCS outweigh the risks of treatment. Finally, this work introduces the future potential of neuropsychological testing for both the diagnosis of DCS as well as assessing the effectiveness of hyperbaric therapy in Type II DCS.

You’re the Flight Surgeon: Pulmonary Decompression Sickness

DTIC Science & Technology

2008-06-01

follow-up of this patient Diagnosis: Decompression sickness (DeS) with pulmonary symptoms (Type Il DeS, older nomenclature). Treatment: Hyperbaric ...is quite clear thai any case of suspected decompression sickness in the USAF be discussed with the hyperbariC medicine specialists at Brooks City...physician in as respectful manner as you can that you suspect the patient’s condition is likely related to his hypobaric exposure. B. Agree with

Microendoscopic posterior decompression for the treatment of thoracic myelopathy caused by ossification of the ligamentum flavum: a technical report.

PubMed

Baba, Satoshi; Oshima, Yasushi; Iwahori, Tomoyuki; Takano, Yuichi; Inanami, Hirohiko; Koga, Hisashi

2016-06-01

Ossification of the ligamentum flavum (OLF) is a common cause of progressive thoracic myelopathy in East Asia. Good surgical results are expected for patients who already show myelopathy. Surgical decompression using a posterior approach is commonly used to treat OLF. This study investigated the use of microendoscopic posterior decompression for the treatment of thoracic OLF. Microendoscopic posterior decompression was performed on 9 patients with myelopathy. Patients had a mean age of 59.8 years and single-level involvement, mostly at the T10-11 and T11-12 vertebrae. Computed tomography and magnetic resonance imaging were used to classify the OLF. A tubular retractor and endoscopic system were used for microendoscopic posterior decompression. Midline and unilateral paramedian approaches were performed in 2 and 7 patients, respectively. Intraoperative motor evoked potentials (MEPs) of 7 patients were monitored. Pre- and postoperative neurological status was evaluated using the modified Japanese Orthopaedic Association (mJOA) score. Thoracic OLF for all patients were classed as bilateral type with a round morphology. Improvement of MEPs at least one muscle area was recorded in all patients following posterior decompression. A dural tear in one patient was the only observed complication. The mean recovery rate was 44.9 %, as calculated from mJOA scores at a mean follow-up period of 20 months. Microendoscopic posterior decompression combined with MEP monitoring can be used to treat patients with thoracic OLF. The optimal surgical indication is OLF at a single vertebral level and of a unilateral or bilateral nature, without comma and tram track signs, and a round morphology.

A Log Logistic Survival Model Applied to Hypobaric Decompression Sickness

NASA Technical Reports Server (NTRS)

Conkin, Johnny

2001-01-01

Decompression sickness (DCS) is a complex, multivariable problem. A mathematical description or model of the likelihood of DCS requires a large amount of quality research data, ideas on how to define a decompression dose using physical and physiological variables, and an appropriate analytical approach. It also requires a high-performance computer with specialized software. I have used published DCS data to develop my decompression doses, which are variants of equilibrium expressions for evolved gas plus other explanatory variables. My analytical approach is survival analysis, where the time of DCS occurrence is modeled. My conclusions can be applied to simple hypobaric decompressions - ascents lasting from 5 to 30 minutes - and, after minutes to hours, to denitrogenation (prebreathing). They are also applicable to long or short exposures, and can be used whether the sufferer of DCS is at rest or exercising at altitude. Ultimately I would like my models to be applied to astronauts to reduce the risk of DCS during spacewalks, as well as to future spaceflight crews on the Moon and Mars.

Outcome after decompressive craniectomy for the treatment of severe traumatic brain injury.

PubMed

Howard, Jerry Lee; Cipolle, Mark D; Anderson, Meredith; Sabella, Victoria; Shollenberger, Daniele; Li, P Mark; Pasquale, Michael D

2008-08-01

Using decompressive craniectomy as part of the treatment regimen for severe traumatic brain injury (STBI) has become more common at our Level I trauma center. This study was designed to examine this practice with particular attention to long-term functional outcome. A retrospective review of prospectively collected data was performed for patients with STBI admitted from January 1, 2003 to December 31, 2005. Our institution manages patients using the Brain Trauma Foundation Guidelines. Data collected from patients undergoing decompressive craniectomy included: age, Injury Severity Score, admission and follow-up Glasgow Coma Score, timing of, and indication for decompressive craniectomy, and procedure-related complications. The Extended Glasgow Outcome Scale (GOSE) was performed by a experienced trauma clinical research coordinator using a structured phone interview to assess long-term outcome in the survivors. Student's t test and chi2 were used to examine differences between groups. Forty STBI patients were treated with decompressive craniectomy; 24 were performed primarily in conjunction with urgent evacuation of extra-axial hemorrhage and 16 were performed primarily in response to increased intracranial pressure with 4 of these after an initial craniotomy. Decompressive craniectomy was very effective at lowering intracranial pressure in these 16 patients (35.0 mm Hg +/- 13.5 mm Hg to 14.6 mm Hg +/- 8.7 mm Hg, p = 0.005). Twenty-two decompressive craniectomy patients did not survive to hospital discharge, whereas admission Glasgow Coma Score and admission pupil size and reactivity correlated with outcome, age, and Injury Severity Score did not. At a mean of 11 months (range, 3-26 months) after decompressive craniectomy, 6 survivors had a poor functional outcome (GOSE 1-4), whereas 12 survivors had a good outcome (GOSE 5-8). Therefore, 70% of these patients had an unfavorable outcome (death or severe disability), and 30% had a favorable long-term functional outcome

Biomechanics of the lower thoracic spine after decompression and fusion: a cadaveric analysis.

PubMed

Lubelski, Daniel; Healy, Andrew T; Mageswaran, Prasath; Benzel, Edward C; Mroz, Thomas E

2014-09-01

Few studies have evaluated the extent of biomechanical destabilization of thoracic decompression on the upper and lower thoracic spine. The present study evaluates lower thoracic spinal stability after laminectomy, unilateral facetectomy, and unilateral costotransversectomy in thoracic spines with intact sternocostovertebral articulations. To assess the biomechanical impact of decompression and fixation procedures on lower thoracic spine stability. Biomechanical cadaveric study. Sequential surgical decompression (laminectomy, unilateral facetectomy, unilateral costotransversectomy) and dorsal fixation were performed on the lower thoracic spine (T8-T9) of human cadaveric spine specimens with intact rib cages (n=10). An industrial robot was used to apply pure moments to simulate flexion-extension (FE), lateral bending (LB), and axial rotation (AR) in the intact specimens and after decompression and fixation. Global range of motion (ROM) between T1-T12 and intrinsic ROM between T7-T11 were measured for each specimen. The decompression procedures caused no statistically significant change in either global or intrinsic ROM compared with the intact state. Instrumentation, however, reduced global motion for AR (45° vs. 30°, p=.0001), FE (24° vs. 19°, p=.02), and LB (47° vs. 36°, p=.0001) and for intrinsic motion for AR (17° vs. 4°, p=.0001), FE (8° vs. 1°, p=.0001), and LB (12° vs. 1°, p=.0001). No significant differences were identified between decompression of the upper versus lower thoracic spine, with trends toward significantly greater ROM for AR and lower ROM for LB in the lower thoracic spine. The lower thoracic spine was not destabilized by sequential unilateral decompression procedures. Addition of dorsal fixation increased segment rigidity at intrinsic levels and also reduced overall ROM of the lower thoracic spine to a greater extent than did fusing the upper thoracic spine (level of the true ribs). Despite the lack of true ribs, the lower thoracic

Health care worker decompression sickness: incidence, risk and mitigation.

PubMed

Clarke, Richard

2017-01-01

Inadvertent exposure to radiation, chemical agents and biological factors are well recognized hazards associated with the health care delivery system. Less well appreciated yet no less harmful is risk of decompression sickness in those who accompany patients as inside attendants (IAs) during provision of hyperbaric oxygen therapy. Unlike the above hazards where avoidance is practiced, IA exposure to decompression sickness risk is unavoidable. While overall incidence is low, when calculated as number of cases over number of exposures or potential for a case during any given exposure, employee cumulative risk, defined here as number of cases over number of IAs, or risk that an IA may suffer a case, is not. Commonly, this unique occupational environmental injury responds favorably to therapeutic recompression and a period of recuperation. There are, however, permanent and career-ending consequences, and at least two nurses have succumbed to their decompression insults. The intent of this paper is to heighten awareness of hyperbaric attendant decompression sickness. It will serve as a review of reported cases and reconcile incidence against largely ignored individual worker risk. Mitigation strategies are summarized and an approach to more precisely identify risk factors that might prompt development of consensus screening standards is proposed. Copyright© Undersea and Hyperbaric Medical Society.

The effect of rapid and sustained decompression on barotrauma in juvenile brook lamprey and Pacific lamprey: implications for passage at hydroelectric facilities

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

Colotelo, Alison HA; Pflugrath, Brett D.; Brown, Richard S.

Fish passing downstream through hydroelectric facilities may pass through hydroturbines where they experience a rapid decrease in barometric pressure as they pass by turbine blades, which can lead to barotraumas including swim bladder rupture, exopthalmia, emboli, and hemorrhaging. In juvenile Chinook salmon, the main mechanism for injury is thought to be expansion of existing gases (particularly those present in the swim bladder) and the rupture of the swim bladder ultimately leading to exopthalmia, emboli and hemorrhaging. In fish that lack a swim bladder, such as lamprey, the rate and severity of barotraumas due to rapid decompression may be reduced however;more » this has yet to be extensively studied. Another mechanism for barotrauma can be gases coming out of solution and the rate of this occurrence may vary among species. In this study, juvenile brook and Pacific lamprey acclimated to 146.2 kPa (equivalent to a depth of 4.6 m) were subjected to rapid (<1 sec; brook lamprey only) or sustained decompression (17 minutes) to a very low pressure (13.8 kPa) using a protocol previously applied to juvenile Chinook salmon. No mortality or evidence of barotraumas, as indicated by the presence of hemorrhages, emboli or exopthalmia, were observed during rapid or sustained decompression, nor following recovery for up to 120 h following sustained decompression. In contrast, mortality or injury would be expected for 97.5% of juvenile Chinook salmon exposed to a similar rapid decompression to these very low pressures. Additionally, juvenile Chinook salmon experiencing sustained decompression died within 7 minutes, accompanied by emboli in the fins and gills and hemorrhaging in the tissues. Thus, juvenile lamprey may not be susceptible to barotraumas associated with hydroturbine passage to the same degree as juvenile salmonids, and management of these species should be tailored to their specific morphological and physiological characteristics.« less

Pediatric and adult vision restoration after optic nerve sheath decompression for idiopathic intracranial hypertension.

PubMed

Bersani, Thomas A; Meeker, Austin R; Sismanis, Dimitrios N; Carruth, Bryant P

2016-06-01

To compare presentations of idiopathic intracranial hypertension and efficacy of optic nerve sheath decompression between adult and pediatric patients, a retrospective cohort study was completed All idiopathic intracranial hypertension patients undergoing optic nerve sheath decompression by one surgeon between 1991 and 2012 were included. Pre-operative and post-operative visual fields, visual acuity, color vision, and optic nerve appearance were compared between adult and pediatric (<18 years) populations. Outcome measures included percentage of patients with complications or requiring subsequent interventions. Thirty-one adults (46 eyes) and eleven pediatric patients (18 eyes) underwent optic nerve sheath decompression for vision loss from idiopathic intracranial hypertension. Mean deviation on visual field, visual acuity, color vision, and optic nerve appearance significantly improved across all subjects. Pre-operative mean deviation was significantly worse in children compared to adults (p=0.043); there was no difference in mean deviation post-operatively (p=0.838). Significantly more pediatric eyes (6) presented with light perception only or no light perception than adult eyes (0) (p=0.001). Pre-operative color vision performance in children (19%) was significantly worse than in adults (46%) (p=0.026). Percentage of patients with complications or requiring subsequent interventions did not differ between groups. The consistent improvement after surgery and low rate of complications suggest optic nerve sheath decompression is safe and effective in managing vision loss due to adult and pediatric idiopathic intracranial hypertension. Given the advanced pre-operative visual deficits seen in children, one might consider a higher index of suspicion in diagnosing, and earlier surgical intervention in treating pediatric idiopathic intracranial hypertension.

Patterns and Variations in Microvascular Decompression for Trigeminal Neuralgia

PubMed Central

TODA, Hiroki; GOTO, Masanori; IWASAKI, Koichi

2015-01-01

Microvascular decompression (MVD) is a highly effective surgical treatment for trigeminal neuralgia (TN). Although there is little prospective clinical evidence, accumulated observational studies have demonstrated the benefits of MVD for refractory TN. In the current surgical practice of MVD for TN, there have been recognized patterns and variations in surgical anatomy and various decompression techniques. Here we provide a stepwise description of surgical procedures and relevant anatomical characteristics, as well as procedural options. PMID:25925756

Magma degassing triggered by static decompression at Kīlauea Volcano, Hawai‘i

USGS Publications Warehouse

Poland, Michael P.; Jeff, Sutton A.; Gerlach, Terrence M.

2009-01-01

During mid-June 2007, the summit of Kīlauea Volcano, Hawai‘i, deflated rapidly as magma drained from the subsurface to feed an east rift zone intrusion and eruption. Coincident with the deflation, summit SO2 emission rates rose by a factor of four before decaying to background levels over several weeks. We propose that SO2 release was triggered by static decompression caused by magma withdrawal from Kīlauea's shallow summit reservoir. Models of the deflation suggest a pressure drop of 0.5–3 MPa, which is sufficient to trigger exsolution of the observed excess SO2 from a relatively small volume of magma at the modeled source depth beneath Kīlauea's summit. Static decompression may also explain other episodes of deflation accompanied by heightened gas emission, including the precursory phases of Kīlauea's 2008 summit eruption. Hazards associated with unexpected volcanic gas emission argue for increased awareness of magma reservoir pressure fluctuations.

Nerve Decompression Surgery After Total Hip Arthroplasty: What Are the Outcomes?

PubMed

Chughtai, Morad; Khlopas, Anton; Gwam, Chukwuwieke U; Elmallah, Randa K; Thomas, Melbin; Nace, James; Mont, Michael A

2017-04-01

The purpose of our study was to compare (1) muscle strength; (2) pain; (3) sensation; (4) various outcome measurement scales between post-total hip arthroplasty (THA) patients who had a sciatic nerve injury and did or did not receive decompression surgery for this condition; and (5) to compare these findings with current literature. Nineteen patients who had nerve injury after THA were reviewed. Patients were stratified into those who had a nerve decompression (n = 12), and those who had not (n = 7). Motor strength was evaluated using the Muscle Strength Testing Scale. Pain was evaluated by using the visual analogue scale. Systematic literature search was performed to compare the findings of this study with others currently published. The decompression group had a significant improvement in motor strength and the visual analog scale scores as compared with nonoperative group. Patients in decompression group had a significant larger increase in the mean Harris hip score and University of California Los Angeles score. There was no significant difference in the increase of Short Form-36 physical and mental scores between the 2 groups. Literature review for nonoperative management yielded 5 studies (93 patients), with 33% improvement. There were 7 studies (81 patients) on nerve decompression surgery, with 75% improvement. This study demonstrates the benefits of nerve decompression surgery in patients who had sciatic nerve injury after THA, as evidenced by results of standardized outcome measurement scales. It is possible to achieve improvements in terms of strength, pain, and clinical outcomes. Comparative studies with larger cohorts are needed to fully assess the best candidates for this procedure. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of an impedance threshold device in patients receiving active compression-decompression cardiopulmonary resuscitation for out of hospital cardiac arrest.

PubMed

Plaisance, Patrick; Lurie, Keith G; Vicaut, Eric; Martin, Dominique; Gueugniaud, Pierre-Yves; Petit, Jean-Luc; Payen, Didier

2004-06-01

The purpose of this multicentre clinical randomized controlled blinded prospective trial was to determine whether an inspiratory impedance threshold device (ITD), when used in combination with active compression-decompression (ACD) cardiopulmonary resuscitation (CPR), would improve survival rates in patients with out-of-hospital cardiac arrest. Patients were randomized to receive either a sham (n = 200) or an active impedance threshold device (n = 200) during advanced cardiac life support performed with active compression-decompression cardiopulmonary resuscitation. The primary endpoint of this study was 24 h survival. The 24 h survival rates were 44/200 (22%) with the sham valve and 64/200 (32%) with the active valve (P = 0.02). The number of patients who had a return of spontaneous circulation (ROSC), intensive care unit (ICU) admission, and hospital discharge rates was 77 (39%), 57 (29%), and 8 (4%) in the sham valve group versus 96 (48%) (P = 0.05), 79 (40%) (P = 0.02), and 10 (5%) (P = 0.6) in the active valve group. Six out of ten survivors in the active valve group and 1/8 survivors in the sham group had normal neurological function at hospital discharge (P = 0.1). The use of an impedance valve in patients receiving active compression-decompression cardiopulmonary resuscitation for out-of-hospital cardiac arrest significantly improved 24 h survival rates.

Transnasal Endoscopic Optic Nerve Decompression in Post Traumatic Optic Neuropathy.

PubMed

Gupta, Devang; Gadodia, Monica

2018-03-01

To quantify the successful outcome in patients following optic nerve decompression in post traumatic unilateral optic neuropathy in form of improvement in visual acuity. A prospective study was carried out over a period of 5 years (January 2011 to June 2016) at civil hospital Ahmedabad. Total 20 patients were selected with optic neuropathy including patients with direct and indirect trauma to unilateral optic nerve, not responding to conservative management, leading to optic neuropathy and subsequent impairment in vision and blindness. Decompression was done via Transnasal-Ethmo-sphenoidal route and outcome was assessed in form of post-operative visual acuity improvement at 1 month, 6 months and 1 year follow up. After surgical decompression complete recovery of visual acuity was achieved in 16 (80%) patients and partial recovery in 4 (20%). Endoscopic transnasal approach is beneficial in traumatic optic neuropathy not responding to steroid therapy and can prevent permanent disability if earlier intervention is done prior to irreversible damage to the nerve. Endoscopic optic nerve surgery can decompress the traumatic and oedematous optic nerve with proper exposure of orbital apex and optic canal without any major intracranial, intraorbital and transnasal complications.

MRI Evaluation of Post Core Decompression Changes in Avascular Necrosis of Hip.

PubMed

Nori, Madhavi; Marupaka, Sravan Kumar; Alluri, Swathi; Md, Naseeruddin; Irfan, Kazi Amir; Jampala, Venkateshwarlu; Apsingi, Sunil; Eachempati, Krishna Kiran

2015-12-01

Avascular necrosis of hip typically presents in young patients. Core decompression in precollapse stage provides pain relief and preservation of femoral head. The results of core decompression vary considerably despite early diagnosis. The role of MRI in monitoring patients post surgically has not been clearly defined. To study pre and post core decompression MRI changes in avascular necrosis of hip. This is a contiguous observational cohort of 40 hips treated by core decompression for precollapse avascular necrosis of femoral head, who had a baseline MRI performed before surgery. Core decompression of the femoral head was performed within 4 weeks. Follow up radiograph and MRI scans were done at six months. Harris hip score preoperatively, 1 month and 6 months after the surgery was noted. Success in this study was defined as postoperative increase in Harris hip score (HHS) by 20 points and no additional femoral collapse. End point of clinical adverse outcome as defined by fall in Harris hip score was conversion or intention to convert to total hip replacement (THR). MRI parameters in the follow up scan were compared to the preoperative MRI. Effect of core decompression on bone marrow oedema and femoral head collapse was noted. Results were analysed using SPSS software version. Harris hip score improved from 57 to 80 in all patients initially. Six hips had a fall in Harris hip score to mean value of 34.1 during follow up (9 to 12 months) and underwent total hip replacement. MRI predictors of positive outcome are lesions with grade A extent, Grade A & B location. Bone marrow oedema with lesions less than 50% involvement, medial and central location. Careful selection of patients by MR criteria for core decompression provides satisfactory outcome in precollapse stage of avascular necrosis of hip.

MRI Evaluation of Post Core Decompression Changes in Avascular Necrosis of Hip

PubMed Central

Marupaka, Sravan Kumar; Alluri, Swathi; MD, Naseeruddin; Irfan, Kazi Amir; Jampala, Venkateshwarlu; Apsingi, Sunil; Eachempati, Krishna Kiran

2015-01-01

Introduction Avascular necrosis of hip typically presents in young patients. Core decompression in precollapse stage provides pain relief and preservation of femoral head. The results of core decompression vary considerably despite early diagnosis. The role of MRI in monitoring patients post surgically has not been clearly defined. Aim To study pre and post core decompression MRI changes in avascular necrosis of hip. Materials and Methods This is a contiguous observational cohort of 40 hips treated by core decompression for precollapse avascular necrosis of femoral head, who had a baseline MRI performed before surgery. Core decompression of the femoral head was performed within 4 weeks. Follow up radiograph and MRI scans were done at six months. Harris hip score preoperatively, 1 month and 6 months after the surgery was noted. Success in this study was defined as postoperative increase in Harris hip score (HHS) by 20 points and no additional femoral collapse. End point of clinical adverse outcome as defined by fall in Harris hip score was conversion or intention to convert to total hip replacement (THR). MRI parameters in the follow up scan were compared to the preoperative MRI. Effect of core decompression on bone marrow oedema and femoral head collapse was noted. Results were analysed using SPSS software version. Results Harris hip score improved from 57 to 80 in all patients initially. Six hips had a fall in Harris hip score to mean value of 34.1 during follow up (9 to 12 months) and underwent total hip replacement. MRI predictors of positive outcome are lesions with grade A extent, Grade A & B location. Bone marrow oedema with lesions less than 50% involvement, medial and central location. Conclusion Careful selection of patients by MR criteria for core decompression provides satisfactory outcome in precollapse stage of avascular necrosis of hip. PMID:26816966

Greater Occipital Nerve Decompression for Occipital Neuralgia.

PubMed

Jose, Anson; Nagori, Shakil Ahmed; Chattopadhyay, Probodh K; Roychoudhury, Ajoy

2018-05-14

The aim of the study was to evaluate the effectiveness of greater occipital nerve decompression for the management of occipital neuralgia. Eleven patients of medical refractory occipital neuralgia were enrolled in the study. Local anaesthetic blocks were used for confirming diagnosis. All of them underwent surgical decompression of greater occipital nerve at the level of semispinalis capitis and trapezial tunnel. A pre and postoperative questionnaire was used to compare the severity of pain and number of pain episodes/month. Mean pain episodes reported by patients before surgery were 17.1 ± 5.63 episodes per month. This reduced to 4.1 ± 3.51 episodes per month (P < 0.0036) postsurgery. The mean intensity of pain also reduced from a preoperative 7.18 ± 1.33 to a postoperative of 1.73 ± 1.95 (P < 0.0033). Three patients reported complete elimination of pain after surgery while 6 patients reported significant relief of their symptoms. Only 2 patients failed to notice any significant improvement. The mean follow-up period was 12.45 ± 1.29 months. Surgical decompression of greater occipital nerve is a simple and viable treatment modality for the management of occipital neuralgia.

Musculoskeletal-induced Nucleation in Altitude Decompression Sickness

NASA Technical Reports Server (NTRS)

Pollock, N. W.; Natoli, M. J.; Conkin, J.; Wessel, J. H., III; Gernhardt, M. L.

2014-01-01

Musculoskeletal activity has the potential to both improve and compromise decompression safety. Exercise enhances inert gas elimination during oxygen breathing prior to decompression (prebreathe), but it may also promote bubble nuclei formation (nucleation), which can lead to gas phase separation and bubble growth and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of musculoskeletal activity and the level of tissue supersaturation may be critical to the net effect. There are limited data available to evaluate cost-benefit relationships. Understanding the relationship is important to improve our understanding of the underlying mechanisms of nucleation in exercise prebreathe protocols and to quantify risk in gravity and microgravity environments. Data gathered during NASA's Prebreathe Reduction Program (PRP) studies combined oxygen prebreathe and exercise followed by low pressure (4.3 psi; altitude equivalent of 30,300 ft [9,235 m]) microgravity simulation to produce two protocols used by astronauts preparing for extravehicular activity. Both the Phase II/CEVIS (cycle ergometer vibration isolation system) and ISLE (in-suit light exercise) trials eliminated ambulation to more closely simulate the microgravity environment. The CEVIS results (35 male, 10 female) serve as control data for this NASA/Duke study to investigate the influence of ambulation exercise on bubble formation and the subsequent risk of DCS.

Oxygen equipment and rapid decompression studies.

DOT National Transportation Integrated Search

1979-03-01

This is a collection of reports of evaluations of the protective capability of various oxygen systems at high altitude and during rapid decompression. Results of these studies were presented at scientific meetings and/or published in preprints or pro...

Minimally invasive decompression surgery for lumbar spinal stenosis with degenerative scoliosis: Predictive factors of radiographic and clinical outcomes.

PubMed

Minamide, Akihito; Yoshida, Munehito; Iwahashi, Hiroki; Simpson, Andrew K; Yamada, Hiroshi; Hashizume, Hiroshi; Nakagawa, Yukihiro; Iwasaki, Hiroshi; Tsutsui, Shunji; Kagotani, Ryohei; Sonekatsu, Mayumi; Sasaki, Takahide; Shinto, Kazunori; Deguchi, Tsuyoshi

2017-05-01

There is ongoing controversy regarding the most appropriate surgical treatment for lumbar spinal stenosis (LSS) with concurrent degenerative lumbar scoliosis (DLS): decompression alone, decompression with limited spinal fusion, or long spinal fusion for deformity correction. The coexistence of degenerative stenosis and deformity is a common scenario; Nonetheless, selecting the appropriate surgical intervention requires thorough understanding of the patients clinical symptomatology as well as radiographic parameters. Minimally invasive (MIS) decompression surgery was performed for LSS patients with DLS. The aims of this study were (1) to investigate the clinical outcomes of MIS decompression surgery in LSS patients with DLS, and (2) to identify the predictive factors for both radiographic and clinical outcomes after MIS surgery. 438 consecutive patients were enrolled in this study. Inclusion criteria was evidence of LSS and DLS with coronal curvature measuring greater than 10°. The Japanese Orthopaedic Association (JOA) score, JOA recovery rate, low back pain (LBP), and radiographic features were evaluated preoperatively and at over 2 years postoperatively. Of the 438 patients, 122 were included in final analysis, with a mean follow-up of 2.4 years. The JOA recovery rate was 47.6%. LBP was significantly improved at final follow-up. Cobb angle was maintained for 2 years postoperatively (p = 0.159). Clinical outcomes in foraminal stenosis patients were significantly related to sex, preoperative high Cobb angle and progression of scoliosis (p = 0.008). In the severe scoliosis patients, the JOA recovery was 44%, and was significantly depended on progression of scoliosis (Cobb angle: preoperation 29.6°, 2-years follow-up 36.9°) and mismatch between the pelvic incidence (PI) and the lumbar lordosis (LL) (preoperative PI-LL 35.5 ± 21.2°) (p = 0.028). This study investigated clinical outcomes of MIS decompression surgery in LSS patients with DLS. The predictive

Paraspinal muscle impingement causing acute Brown-Sequard syndrome after posterior cervical decompression.

PubMed

Jost, Patrick W; Marawar, Satyajit; O'Leary, Patrick F

2010-04-01

A case report. To present a previously unreported cause of neurologic compromise after cervical spine surgery. Several different causes of postoperative neurologic deficit have been reported in the literature. The authors present a case of acute postoperative paralysis after posterior cervical decompression by a mechanism that has not yet been reported in the literature. A 54-year-old muscular, short-statured man underwent posterior cervical laminectomy from C3-C5 without instrumentation and left C5 foraminotomy. Within hours of leaving the operating room, he began to develop postoperative neurologic deficits in his extremities, which progressed to a classic Brown-Sequard syndrome. Magnetic resonance imaging revealed regional kyphosis and large swollen paraspinal muscles impinging on the spinal cord without epidural hematoma. Emergent operative re-exploration confirmed these findings; large, swollen paraspinal muscles, a functioning drain, and no hematoma were found. The patient was treated with immediate corticosteroids at the time of initial diagnosis, and emergent re-exploration and debulking of the paraspinal muscles. The patient had complete recovery of neurologic function to his preoperative baseline after the second procedure but required a third procedure in which anterior discectomy and fusion at C4-C5 was performed, which led to improvement of his preoperative symptoms. When performing posterior cervical decompression, surgeons must be aware of the potential for loss of normal lordosis and anterior displacement of paraspinal muscles against the spinal cord, especially in muscular patients.

Risk of decompression sickness in the presence of circulating microbubbles

NASA Technical Reports Server (NTRS)

Kumar, K. Vasantha; Powell, Michael R.

1993-01-01

In this study, we examined the association between microbubbles formed in the circulation from a free gas phase and symptoms of altitude decompression sickness (DCS). In a subgroup of 59 males of mean (S.D) age 31.2 (5.8) years who developed microbubbles during exposure to 26.59 kPa (4.3 psi) under simulated extravehicular activities (EVA), symptoms of DCS occurred in 24 (41 percent) individuals. Spencer grade 1 microbubbles occurred in 4 (7 percent), grade 2 in 9 (15 percent), grade 3 in 15 (25 percent), and grade 4 in 31 (53 percent) of subjects. Survival analysis using Cox proportional hazards regression showed that individuals with less than grade 3 CMB showed 2.46 times (95 percent confidence interval = 1.26 to 5.34) higher risk of symptoms. This information is crucial for defining the risk of DCS for inflight Doppler monitoring under space EVA. Altitude decompression sickness (DCS) occurs when there is acute reduction in ambient pressure. The symptoms of DCS are due to the formation of a free gas phase (in the form of gas microbubbles) in tissues during decompression. Musculo-skeletal pain of bends is the commonest form of DCS in altitude exposures. In the space flight environment, there is a risk of DCS when astronauts decompress from the normobaric shuttle pressure into the hypobaric space suit pressure (currently about 29.65 kPa (4.3 psi) for extra-vehicular activities (EVA). This risk is counterbalanced by a judicious combination of prior denitrogenation and staged decompression. Studies of DCS are limited by the duration of the test at reduced pressure. Since only a proportion of subjects tested develop symptoms, the information on DCS is generally incomplete or 'censored'. Many studies employ Doppler ultrasound monitoring of the precordial area for detecting circulating microbubbles (CMB). Although the association between CMB and bends pain is not causal, CMB are frequently monitored during decompression. In this paper, we examine the association

Twisting Tourniquet(©) Technique: introducing Schnogh, a novel device and its effectiveness in treating primary and secondary lymphedema of extremities.

PubMed

Chanwimalueang, Narumon; Ekataksin, Wichai; Piyaman, Parkpoom; Pattanapen, Gedsuda; Hanboon, Borimas K

2015-10-01

Twisting Tourniquet(©) or in Thai "Schnogh" is a new invention for compression therapy of lymphedema. Twisting Tourniquet(©) Technique (TTT) is totally noninvasive for lymphedema management. After the amazing successful evidence in the first series of 28 patients, we have conducted preliminary studies in lymphedema clinics. It was found that the combination of gradually increasing constriction force by Schnogh until desired pressure was reached and maintained for 15 min, followed by a 5-min release, doing repeatedly this compression-decompression for at least 10 sessions a day, can generate acceptable results. The aim of the study was to evaluate the scientific effectiveness and establish a treatment protocol of TTT proposed as a therapeutic approach for clinical management of lymphedema. During 2006-2013, from over 3500 patients, 647 with primary/secondary lymphedema passed inclusion criteria, 307 for upper, and 340 for lower extremity. In the 5-day course of TTT, each day patients underwent 10 sessions of a 15-min compression followed by a 5-min decompression. Vegan diet was encouraged as an adjuvant therapy. Among lymphedema patients whose spectrum of edema severity ranged from mild to gigantic, TTT yielded an average volume reduction rate (VR) at 50.2% and 55.6%, making the average edema reduction volume attained at 463 and 1856 mL for upper and lower limb, respectively. The uniformed practice by Schnogh which supports a continual compression-decompression maneuver over 3.5 h daily for five consecutive days could induce an average VR at above half of the swelling in extremities of 647 patients. Schnogh is therefore effective in clinical management of lymphedema under TTT treatment of fibroblastic interstitium. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Decryption-decompression of AES protected ZIP files on GPUs

NASA Astrophysics Data System (ADS)

Duong, Tan Nhat; Pham, Phong Hong; Nguyen, Duc Huu; Nguyen, Thuy Thanh; Le, Hung Duc

2011-10-01

AES is a strong encryption system, so decryption-decompression of AES encrypted ZIP files requires very large computing power and techniques of reducing the password space. This makes implementations of techniques on common computing system not practical. In [1], we reduced the original very large password search space to a much smaller one which surely containing the correct password. Based on reduced set of passwords, in this paper, we parallel decryption, decompression and plain text recognition for encrypted ZIP files by using CUDA computing technology on graphics cards GeForce GTX295 of NVIDIA, to find out the correct password. The experimental results have shown that the speed of decrypting, decompressing, recognizing plain text and finding out the original password increases about from 45 to 180 times (depends on the number of GPUs) compared to sequential execution on the Intel Core 2 Quad Q8400 2.66 GHz. These results have demonstrated the potential applicability of GPUs in this cryptanalysis field.

The incidences of and consultation rate for lower extremity complaints in general practice

PubMed Central

van der Waal, J M; Bot, S D M; Terwee, C B; van der Windt, D A W M; Schellevis, F G; Bouter, L M; Dekker, J

2006-01-01

Objective To estimate the incidence and consultation rate of lower extremity complaints in general practice. Methods Data were obtained from the Second Dutch National Survey of General Practice, in which 195 general practitioners (GPs) in 104 practices recorded all contacts with patients during 12 consecutive months in computerised patient records. GPs classified the symptoms and diagnosis for each patient at each consultation according to the International Classification of Primary Care (ICPC). Incidence densities and consultation rates for different complaints were calculated. Results During the registration period 63.2 GP consultations per 1000 person‐years were attributable to a new complaint of the lower extremities. Highest incidence densities were seen for knee complaints: 21.4 per 1000 person‐years for women and 22.8 per 1000 person‐years for men. The incidence of most lower extremity complaints was higher for women than for men and higher in older age. Conclusions Both incidences of and consultation rates for lower extremity complaints are substantial in general practice. This implies a considerable impact on the workload of the GP. PMID:16269430

A comparative evaluation of two decompression procedures for technical diving using inflammatory responses: compartmental versus ratio deco.

PubMed

Spisni, Enzo; Marabotti, Claudio; De Fazio, Luigia; Valerii, Maria Chiara; Cavazza, Elena; Brambilla, Stefano; Hoxha, Klarida; L'Abbate, Antonio; Longobardi, Pasquale

2017-03-01

The aim of this study was to compare two decompression procedures commonly adopted by technical divers: the ZH-L16 algorithm modified by 30/85 gradient factors (compartmental decompression model, CDM) versus the 'ratio decompression strategy' (RDS). The comparison was based on an analysis of changes in diver circulating inflammatory profiles caused by decompression from a single dive. Fifty-one technical divers performed a single trimix dive to 50 metres' sea water (msw) for 25 minutes followed by enriched air (EAN50) and oxygen decompression. Twenty-three divers decompressed according to a CDM schedule and 28 divers decompressed according to a RDS schedule. Peripheral blood for detection of inflammatory markers was collected before and 90 min after diving. Venous gas emboli were measured 30 min after diving using 2D echocardiography. Matched groups of 23 recreational divers (dive to 30 msw; 25 min) and 25 swimmers were also enrolled as control groups to assess the effects of decompression from a standard air dive or of exercise alone on the inflammatory profile. Echocardiography at the single 30 min observation post dive showed no significant differences between the two decompression procedures. Divers adopting the RDS showed a worsening of post-dive inflammatory profile compared to the CDM group, with significant increases in circulating chemokines CCL2 (P = 0.001) and CCL5 (P = 0.006) levels. There was no increase in chemokines following the CDM decompression. The air scuba group also showed a statistically significant increase in CCL2 (P < 0.001) and CCL5 (P = 0.003) levels post dive. No cases of decompression sickness occurred. The ratio deco strategy did not confer any benefit in terms of bubbles but showed the disadvantage of increased decompression-associated secretion of inflammatory chemokines involved in the development of vascular damage.

Chronic Decompression Illness Cognitive Dysfunction Improved with Hyperbaric Oxygen: A Case Report

DTIC Science & Technology

2018-11-09

Altitude chamber exposures are used for training to allow aircrew to experience their hypoxia and pressure effect symptoms. Decompression illness ...chamber decompression illness is around 0.25% (1). Because the evolution of gas within the tissue or vasculature is being treated upon recompression

Trends in Orbital Decompression Techniques of Surveyed American Society of Ophthalmic Plastic and Reconstructive Surgery Members.

PubMed

Reich, Shani S; Null, Robert C; Timoney, Peter J; Sokol, Jason A

To assess current members of the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) regarding preference in surgical techniques for orbital decompression in Graves' disease. A 10-question web-based, anonymous survey was distributed to oculoplastic surgeons utilizing the ASOPRS listserv. The questions addressed the number of years of experience performing orbital decompression surgery, preferred surgical techniques, and whether orbital decompression was performed in collaboration with an ENT surgeon. Ninety ASOPRS members participated in the study. Most that completed the survey have performed orbital decompression surgery for >15 years. The majority of responders preferred a combined approach of floor and medial wall decompression or balanced lateral and medial wall decompression; only a minority selected a technique limited to 1 wall. Those surgeons who perform fat decompression were more likely to operate in collaboration with ENT. Most surgeons rarely remove the orbital strut, citing risk of worsening diplopia or orbital dystopia except in cases of optic nerve compression or severe proptosis. The most common reason given for performing orbital decompression was exposure keratopathy. The majority of surgeons perform the surgery without ENT involvement, and number of years of experience did not correlate significantly with collaboration with ENT. The majority of surveyed ASOPRS surgeons prefer a combined wall approach over single wall approach to initial orbital decompression. Despite the technological advances made in the field of modern endoscopic surgery, no single approach has been adopted by the ASOPRS community as the gold standard.

Technique for Mini-open Decompression of Chiari Type I Malformation in Adults.

PubMed

Pakzaban, Peyman

2017-08-01

The technique for decompression of Chiari type I malformation relies on open exposure of craniocervical junction for suboccipital craniectomy and upper cervical laminectomy with or without duraplasty. There is no detailed technical report of a minimally invasive approach for Chiari decompression in adults. To describe a mini-open technique for decompression of Chiari type I malformation (including duraplasty) in adults. Six consecutive adult patients with symptomatic Chiari type I malformation underwent decompression through a 3 to 4 cm midline incision via a speculum retractor. All patients underwent a limited suboccipital craniectomy and C1 laminectomy with an ultrasonic bone scalpel. All patients underwent duraplasty with a synthetic dural substitute. In the 2 patients with syringomyelia, the arachnoid was opened and intradural dissection was carried out. In the remaining 4 patients, the arachnoid was left intact. All operations were completed successfully through the mini-open exposure. Mean surgery time, blood loss, and length of stay were 114 min, 55 mL, and 1.3 days, respectively. Mean follow-up was 13.2 months (range 9-18). All patients had excellent clinical outcomes as defined by scores of 15 (3 patients) or 16 (3 patients) on Chicago Chiari Outcome Scale. There were no neurological complications or cerebrospinal fluid leaks. Postop computed tomography revealed good boney decompression. In the 2 patients with syringomyelia, MRI at 6 months revealed resolution of the syrinx. Decompression of Chiari type I malformation in adults can be performed safely and effectively through the mini-open exposure described in this report. Copyright © 2017 by the Congress of Neurological Surgeons

Unusual Clinical Presentation and Role of Decompressive Craniectomy in Herpes Simplex Encephalitis.

PubMed

Singhi, Pratibha; Saini, Arushi Gahlot; Sahu, Jitendra Kumar; Kumar, Nuthan; Vyas, Sameer; Vasishta, Rakesh Kumar; Aggarwal, Ashish

2015-08-01

Decompressive craniectomy in pediatric central nervous infections with refractory intracranial hypertension is less commonly practiced. We describe improved outcome of decompressive craniectomy in a 7-year-old boy with severe herpes simplex encephalitis and medically refractory intracranial hypertension, along with a brief review of the literature. Timely recognition of refractory intracranial hypertension and surgical decompression in children with herpes simplex encephalitis can be life-saving. Additionally, strokelike atypical presentations are being increasingly recognized in children with herpes simplex encephalitis and should not take one away from the underlying herpes simplex encephalitis. © The Author(s) 2014.

Optic neuropathy in thyroid eye disease: results of the balanced decompression technique.

PubMed

Baril, Catherine; Pouliot, Denis; Molgat, Yvonne

2014-04-01

To determine the efficacy of combined endoscopic medial and external lateral orbital decompression for the treatment of compressive optic neuropathy (CON) in thyroid eye disease (TED). A retrospective review of all patients undergoing combined surgical orbital decompression for CON between 2000 and 2010 was conducted. Fifty-nine eyes of 34 patients undergoing combined surgical orbital decompression for CON. Clinical outcome measures included visual acuity, Hardy-Rand-Rittler (HRR) colour plate testing, relative afferent pupillary defect, intraocular pressure measurement, and Hertel exophthalmometry. A CON score was calculated preoperatively and postoperatively based on the visual acuity and the missed HRR plates. A higher CON score correlates with more severe visual dysfunction. All patients had improvement of their optic neuropathy after surgical decompression. CON score was calculated for 54 eyes and decreased significantly from a mean of 13.2 ± 10.35 preoperatively to a mean of 8.51 ± 10.24 postoperatively (p < 0.0001). Optic neuropathy was completely resolved in 93.22% (55/59 eyes). Eighteen of 34 patients (52.94%) experienced development of new-onset postoperative strabismus that required subsequent surgical intervention. Endoscopic medial combined with external lateral orbital decompression is an effective technique for the treatment of TED-associated CON. © 2013 Canadian Ophthalmological Society Published by Canadian Ophthalmological Society All rights reserved.

Redistribution of Decompression Stop Time from Shallow to Deep Stops Increases Incidence of Decompression Sickness in Air Decompression Dives

DTIC Science & Technology

2011-07-22

year old active duty male diver surfaced from a 170/30 air dive at <corr>12:11<corr> on 24AUG06 using MK 20 FFM and following the A-2 “deep stops...effort, and this episode responded immediately to pressure. AGE is unlikely due to the experience of the diver, the MK 20 FFM characteristics, and...from a 170/30 air dive at <corr>12:11<corr> on 24AUG06 using MK 20 FFM and following the A-2 “deep stops” experimental decompression profile

Decompression sickness and venous gas emboli at 8.3 psia

NASA Technical Reports Server (NTRS)

Smead, Kenneth W.; Dixon, Gene A.; Webb, James T.; Krutz, Robert W., Jr.

1987-01-01

This study sought to determine the bends risk on decompression from sea level to 8.3 psia. On the basis of several prior studies by NASA and the Air Force, this differential was expected to result in a minimal (about 5 percent) incidence of mild decompression sickness, and may be the pressure of choice for the next-generation NASA extravehicular activity (EVA) pressure suit. Thirty-one volunteer subjects, performing light work characteristic of EVA, were exposed to 8.3 psia pressure altitude for six hours. Limb bends incidence was 3.2 percent, and 25.8 percent of the subjects demonstrated significant intravascular bubbling. Those who bubbled were significantly older than the bubble-free group, but differed in no other aspect. An 8.3 psia advanced pressure suit design was considered insufficient to totally preclude the risk of decompression sickness.

Single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral brucellosis.

PubMed

Abulizi, Yakefu; Liang, Wei-Dong; Muheremu, Aikeremujiang; Maimaiti, Maierdan; Sheng, Wei-Bin

2017-07-14

Spinal brucellosis is a less commonly reported infectious spinal pathology. There are few reports regarding the surgical treatment of spinal brucellosis in existing literature. This retrospective study was conducted to determine the effectiveness of single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral spinal brucellosis. From February 2012 to April 2015, 32 consecutive patients (19 males and 13 females, mean age 53.7 ± 8.7) with lumbosacral brucellosis treated by transforaminal decompression, debridement, interbody fusion, and posterior instrumentation were enrolled. Medical records, imaging studies, laboratory data were collected and summarized. Surgical outcomes were evaluated based on visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopaedic Association (JOA) scale. The changes in C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), clinical symptoms and complications were investigated. Graft fusion was evaluated using Bridwell grading criteria. The mean follow-up period was 24.9 ± 8.2 months. Back pain and radiating leg pain was relieved significantly in all patients after operation. No implant failures were observed in any patients. Wound infection was observed in two patients and sinus formation was observed in one patient. Solid bony fusion was achieved in 30 patients and the fusion rate was 93.8%. The levels of ESR and CRP were returned to normal by the end of three months' follow-up. VAS and ODI scores were significantly improved (P < 0.05). According to JOA score, surgical improvement was excellent in 22 cases (68.8%), good in 9 cases (28.1%), moderate in 1 case (3.1%) at the last follow-up. Single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation is an effective and safe approach for lumbosacral brucellosis.

Physiotherapist agreement when visually rating movement quality during lower extremity functional screening tests.

PubMed

Whatman, Chris; Hing, Wayne; Hume, Patria

2012-05-01

To investigate physiotherapist agreement in rating movement quality during lower extremity functional tests using two visual rating methods and physiotherapists with differing clinical experience. Clinical measurement. Six healthy individuals were rated by 44 physiotherapists. These raters were in three groups (inexperienced, novice, experienced). Video recordings of all six individuals performing four lower extremity functional tests were visually rated (dichotomous or ordinal scale) using two rating methods (overall or segment) on two occasions separated by 3-4 weeks. Intra and inter-rater agreement for physiotherapists was determined using overall percentage agreement (OPA) and the first order agreement coefficient (AC1). Intra-rater agreement for overall and segment methods ranged from slight to almost perfect (OPA: 29-96%, AC1: 0.01 to 0.96). AC1 agreement was better in the experienced group (84-99% likelihood) and for dichotomous rating (97-100% likelihood). Inter-rater agreement ranged from fair to good (OPA: 45-79%; AC1: 0.22-0.71). AC1 agreement was not influenced by clinical experience but was again better using dichotomous rating. Physiotherapists' visual rating of movement quality during lower extremity functional tests resulted in slight to almost perfect intra-rater agreement and fair to good inter-rater agreement. Agreement improved with increased level of clinical experience and use of dichotomous rating. Copyright © 2011 Elsevier Ltd. All rights reserved.

Levodopa in Treatment of Decompression Sickness and of Air Embolism Induced Paraplegia in Rats.

DTIC Science & Technology

1981-08-28

nitrosoureas (BCNU, CCNU) made additional progress in the treatment of brain tumors. A lipid soluble agent , 1,3-bis (2-Chloroethyl)-l- Nitrosourea (BCNU...mechanisms of levodopa and some other agents in the prevention and in the recovery of rats from decompression sickness. For better clarity the...brain occurring in decompression sickness. B. Decompression Sickness Studies. We have shown that gelatin, an agent that protects platelets during freezing

Decompression sickness rates for chamber personnel: case series from one facility.

PubMed

Brandt, Megan S; Morrison, Thomas O; Butler, William P

2009-06-01

During 2004, a case series of decompression sickness (DCS) meeting the definition of epidemic DCS was observed in the Shaw AFB Physiological Training Program. There were 10 cases of chamber-induced altitude DCS observed. Internal and external investigations focused on time, place, person, and environment. No temporal trend was observed. Chamber, masks, regulators, crew positions, and oxygen sources revealed no defects. Among the cases, mean age was 27 yr. Peak altitude in four cases was 35,000 ft and in the other six cases was 25,000 ft. Six had joint pain, one skin symptoms, and three neurological findings. Four were treated with 100% ground-level oxygen and six with hyperbaric oxygen. Four were students and six were inside observers (IO). Four were women and six men. In the IO, where four of the six were women, no gender effect was seen. Examining the IO monthly exposure load (exposures per month) against DCS suggested a dose-response relationship. This relationship held true when 4 yr of Shaw AFB IO data was studied. Indeed, Poisson regression analysis demonstrated a statistically significant 2.1-fold rise in DCS risk with each monthly exposure. Consequently, the number of exposures per month may need to be considered when devising IO schedules.

Influence of surgical decompression on the expression of inflammatory and tissue repair biomarkers in periapical cysts.

PubMed

Rodrigues, Janderson Teixeira; Dos Santos Antunes, Henrique; Armada, Luciana; Pires, Fábio Ramôa

2017-12-01

The biologic effects of surgical decompression on the epithelium and connective tissues of periapical cysts are not fully understood. The aim of this study was to evaluate the expression of tissue repair and inflammatory biomarkers in periapical cysts before and after surgical decompression. Nine specimens of periapical cysts treated with decompression before undergoing complete enucleation were immunohistochemically analyzed to investigate the expression of interleukin-1β, tumor necrosis factor-α, transforming growth factor-β1, matrix metalloproteinase-9, Ki-67, and epidermal growth factor receptor. Expression of the biomarkers was classified as positive, focal, or negative. Ki-67 immunoexpression was calculated as a cell proliferation index. The expression of the biomarkers was compared in the specimens from decompression and from the final surgical procedure. Computed tomography demonstrated that volume was reduced in all cysts after decompression. There were no differences in the immunoexpression of the proinflammatory and tissue repair biomarkers when comparing the specimens obtained before and after the decompression. Surgical decompression was efficient in reducing the volume of periapical cysts before complete enucleation. When comparing the specimens obtained from surgical decompression and from complete surgical removal, the immunohistochemical analysis did not show a decrease in proinflammatory biomarkers; neither did it show an increase in tissue repair biomarkers. Copyright © 2017 Elsevier Inc. All rights reserved.

Revisiting Hemicraniectomy: Late Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Stroke and the Role of Infarct Growth Rate

PubMed Central

Akhtar, Naveed; Salam, Abdul; Alboudi, Ayman; Kamran, Kainat; Ahmed, Arsalan; Khan, Rabia A.; Mirza, Mohsin K.; Inshasi, Jihad

2017-01-01

Objective and Methods. The outcome in late decompressive hemicraniectomy in malignant middle cerebral artery stroke and the optimal timings of surgery has not been addressed by the randomized trials and pooled analysis. Retrospective, multicenter, cross-sectional study to measure outcome following DHC under 48 or over 48 hours using the modified Rankin scale [mRS] and dichotomized as favorable ≤4 or unfavorable >4 at three months. Results. In total, 137 patients underwent DHC. Functional outcome analyzed as mRS 0–4 versus mRS 5-6 showed no difference in this split between early and late operated on patients [P = 0.140] and mortality [P = 0.975]. Multivariate analysis showed that age ≥ 55 years, MCA with additional infarction, septum pellucidum deviation ≥1 cm, and uncal herniation were independent predictors of poor functional outcome at three months. In the “best” multivariate model, second infarct growth rate [IGR2] >7.5 ml/hr, MCA with additional infarction, and patients with temporal lobe involvement were independently associated with surgery under 48 hours. Both first infarct growth rate [IGR1] and second infarct growth rate [IGR2] were nearly double [P < 0.001] in patients with early surgery [under 48 hours]. Conclusions. The outcome and mortality in malignant middle cerebral artery stroke patients operated on over 48 hours of stroke onset were comparable to those of patients operated on less than 48 hours after stroke onset. Our data identifies IGR, temporal lobe involvement, and middle cerebral artery with additional infarct as independent predictors for early surgery. PMID:28409051

Revisiting Hemicraniectomy: Late Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Stroke and the Role of Infarct Growth Rate.

PubMed

Kamran, Saadat; Akhtar, Naveed; Salam, Abdul; Alboudi, Ayman; Kamran, Kainat; Ahmed, Arsalan; Khan, Rabia A; Mirza, Mohsin K; Inshasi, Jihad; Shuaib, Ashfaq

2017-01-01

Objective and Methods. The outcome in late decompressive hemicraniectomy in malignant middle cerebral artery stroke and the optimal timings of surgery has not been addressed by the randomized trials and pooled analysis. Retrospective, multicenter, cross-sectional study to measure outcome following DHC under 48 or over 48 hours using the modified Rankin scale [mRS] and dichotomized as favorable ≤4 or unfavorable >4 at three months. Results. In total, 137 patients underwent DHC. Functional outcome analyzed as mRS 0-4 versus mRS 5-6 showed no difference in this split between early and late operated on patients [ P = 0.140] and mortality [ P = 0.975]. Multivariate analysis showed that age ≥ 55 years, MCA with additional infarction, septum pellucidum deviation ≥1 cm, and uncal herniation were independent predictors of poor functional outcome at three months. In the "best" multivariate model, second infarct growth rate [IGR2] >7.5 ml/hr, MCA with additional infarction, and patients with temporal lobe involvement were independently associated with surgery under 48 hours. Both first infarct growth rate [IGR1] and second infarct growth rate [IGR2] were nearly double [ P < 0.001] in patients with early surgery [under 48 hours]. Conclusions. The outcome and mortality in malignant middle cerebral artery stroke patients operated on over 48 hours of stroke onset were comparable to those of patients operated on less than 48 hours after stroke onset. Our data identifies IGR, temporal lobe involvement, and middle cerebral artery with additional infarct as independent predictors for early surgery.

The effect of partial portal decompression on portal blood flow and effective hepatic blood flow in man: a prospective study.

PubMed

Rosemurgy, A S; McAllister, E W; Godellas, C V; Goode, S E; Albrink, M H; Fabri, P J

1995-12-01

With the advent of transjugular intrahepatic porta-systemic stent shunt and the wider application of the surgically placed small diameter prosthetic H-graft portacaval shunt (HGPCS), partial portal decompression in the treatment of portal hypertension has received increased attention. The clinical results supporting the use of partial portal decompression are its low incidence of variceal rehemorrhage due to decreased portal pressures and its low rate of hepatic failure, possibly due to maintenance of blood flow to the liver. Surprisingly, nothing is known about changes in portal hemodynamics and effective hepatic blood flow following partial portal decompression. To prospectively evaluate changes in portal hemodynamics and effective hepatic blood flow brought about by partial portal decompression, the following were determined in seven patients undergoing HGPCS: intraoperative pre- and postshunt portal vein pressures and portal vein-inferior vena cava pressure gradients, intraoperative pre- and postshunt portal vein flow, and pre- and postoperative effective hepatic blood flow. With HGPCS, portal vein pressures and portal vein-inferior vena cava pressure gradients decreased significantly, although portal pressures remained above normal. In contrast to the significant decreases in portal pressures, portal vein blood flow and effective hepatic blood flow do not decrease significantly. Changes in portal vein pressures and portal vein-inferior vena cava pressure gradients are great when compared to changes in portal vein flow and effective hepatic blood flow. Reduction of portal hypertension with concomitant maintenance of hepatic blood flow may explain why hepatic dysfunction is avoided following partial portal decompression.

A Pottery Electric Kiln Using Decompression

NASA Astrophysics Data System (ADS)

Naoe, Nobuyuki; Yamada, Hirofumi; Nakayama, Tetsuo; Nakayama, Minoru; Minamide, Akiyuki; Takemata, Kazuya

This paper presents a novel type electric kiln which fires the pottery using the decompression. The electric kiln is suitable for the environment and the energy saving as the pottery furnace. This paper described the baking principle and the baking characteristic of the novel type electric kiln.

29 CFR Appendix A to Subpart S of... - Decompression Tables

Code of Federal Regulations, 2010 CFR

2010-07-01

... working period at 20 pounds gauge. Decompression Table No. 1: 20 pounds for 4 hours, total decompression... minutes per pound. Stage 2 (final) elapsed time 40 Total time 43 Example No. 2: 5-hour working period at... pressure p.s.i.g. Working period hours 1/2 1 11/2 2 3 4 5 6 7 8 Over 8 9 to 12 3 3 3 3 3 3 3 3 3 3 3 14 6 6...

The Risks of Scuba Diving: A Focus on Decompression Illness

PubMed Central

2014-01-01

Decompression Illness includes both Decompression Sickness (DCS) and Pulmonary Overinflation Syndrome (POIS), subsets of diving-related injury related to scuba diving. DCS is a condition in which gas bubbles that form while diving do not have adequate time to be resorbed or “off-gassed,” resulting in entrapment in specific regions of the body. POIS is due to an overly rapid ascent to the surface resulting in the rupture of alveoli and subsequent extravasation of air bubbles into tissue planes or even the cerebral circulation. Divers must always be cognizant of dive time and depth, and be trained in the management of decompression. A slow and controlled ascent, plus proper control of buoyancy can reduce the dangerous consequences of pulmonary barotrauma. The incidence of adverse effects can be diminished with safe practices, allowing for the full enjoyment of this adventurous aquatic sport. PMID:25478296

Exercise with prebreathe appears to increase protection from decompression sickness: Preliminary findings

NASA Technical Reports Server (NTRS)

Webb, James T.; Fischer, Michele D.; Heaps, Cristine L.; Pilmanis, Andrew A.

1994-01-01

Extravehicular activity (EVA) from the Space Shuttle involves one hour of prebreath with 100% oxygen, decompression of the entire Shuttle to 10.2 psia for at least 12 hours, and another prebreath for 40 minutes before decompression to the 4.3 psia suit pressure. We are investigating the use of a one-hour prebreathe with 100% oxygen beginning with a ten-minute strenuous exercise period as an alternative for the staged decompression schedule described above. The 10-minute exercise consists of dual-cycle ergometry performed at 75% of the subject's peak oxygen uptake to increase denitrogenation efficiency by increasing ventilation and perfusion. The control exposures were preceded by a one-hour prebreathe with 100% oxygen while resting in a supine position. The twenty-two male subjects were exposed to 4.3 psia for 4 hours while performing light to moderate exercise. Preliminary results from 22 of the planned 26 subjects indicate 76% DCS following supine, resting prebreathe and 38% following prebreathe with exercise. The staged decompression schedule has been shown to result in 23% DCS which is not significantly different from the exercise-enhanced prebreathe results. Prebreathe including exercise appears to be comparable to the protection afforded by the more lengthy staged decompression schedule. Completion of the study later this year will enable planned statistical analysis of the results.

Bilateral Ocular Decompression Retinopathy after Ahmed Valve Implantation for Uveitic Glaucoma.

PubMed

Flores-Preciado, Javier; Ancona-Lezama, David Arturo; Valdés-Lara, Carlos Andrés; Díez-Cattini, Gian Franco; Coloma-González, Itziar

2016-01-01

We report the case of a 29-year-old man who underwent Ahmed valve implantation in both eyes as treatment for uveitic glaucoma, subsequently presenting with bilateral ocular decompression retinopathy in the postoperative period. Ocular decompression retinopathy is a rare complication of filtering surgery in patients with glaucoma; however, the course is benign in most cases, with spontaneous resolution of bleedings and improvement of visual acuity.

Surgical decompression of thoracic spinal stenosis in achondroplasia: indication and outcome.

PubMed

Vleggeert-Lankamp, Carmen; Peul, Wilco

2012-08-01

The achondroplastic spinal canal is narrow due to short pedicles and a small interpedicular distance. Compression of neural structures passing through this canal is therefore regularly encountered but rarely described. Symptomatology, radiological evaluation, and treatment of 20 patients with achondroplasia who underwent decompression of the thoracic spinal cord are described and outcome is correlated with the size of the spinal canal and the thoracolumbar kyphotic angle. Scores from the modified Japanese Orthopaedic Association scale, Nurick scale, European Myelopathy scale, Cooper myelopathy scale for lower extremities, and Odom criteria before and after surgery were compared. Magnetic resonance imaging was evaluated to determine the size of the spinal canal, spinal cord compression, and presence of myelomalacia. The thoracolumbar kyphotic angle was measured using fluoroscopy. Patient symptomatology included deterioration of walking pattern, pain, cramps, spasms, and incontinence. Magnetic resonance images of all patients demonstrated spinal cord compression due to degenerative changes. Surgery resulted in a slight improvement on all the ranking scales. Surgery at the wrong level occurred in 15% of cases, but no serious complications occurred. The mean thoracolumbar kyphotic angle was 20°, and no correlation was established between this angle and outcome after surgery. No postoperative increase in this angle was reported. There was also no correlation between size of the spinal canal and outcome. Decompressive surgery of the thoracic spinal cord in patients with achondroplasia can be performed safely if anatomical details are taken into consideration. Spondylodesis did not appear essential. Special attention should be given to the method of surgery, identification of the level of interest, and follow-up of the thoracolumbar kyphotic angle.

Bipolar vulnerability and extreme appraisals of internal states: a computerized ratings study.

PubMed

Dodd, Alyson L; Mansell, Warren; Morrison, Anthony P; Tai, Sara

2011-01-01

A recent integrative cognitive model proposed that multiple, extreme, personalized, positive and negative appraisals of internal states predispose to maintain and exacerbate bipolar symptoms. This study aimed to directly assess conviction in a range of positive and negative appraisals of internal states suggested by the model, by using a laboratory-based computerized task. In a student sample (n = 68), a history of hypomania was associated with more positive and less negative appraisals of internal states, and a history of depression was associated with more negative appraisals and less positive appraisals of internal states. The sample was then split into three groups for comparison: bipolar risk (n = 18), depression risk (n = 20) and controls (n  = 30). Relative to controls, the bipolar risk group made more extreme ratings of catastrophic appraisals of low activation states and tended to make more extreme ratings of appraisals of high activation states. The depression risk group scored higher on a range of negative appraisals of low activation states. These findings provide tentative support for the role of both positive and negative, extreme, personalized appraisals of internal states in hypomania and depression. Copyright © 2011 John Wiley & Sons, Ltd.

Core decompression of the equine navicular bone: an in vivo study in healthy horses.

PubMed

Jenner, Florien; Kirker-Head, Carl

2011-02-01

To determine the physiologic response of the equine navicular bone to core decompression surgery in healthy horses. Experimental in vivo study. Healthy adult horses (n=6). Core decompression was completed by creating three 2.5-mm-diameter drill channels into the navicular bone under arthroscopic control. The venous (P(V)), arterial (P(A)), articular (P(DIPJ)), and intraosseous pressures (IOP) were recorded before and after decompression drilling. Each IOP measurement consisted of a baseline (IOP(B)) and a stress test (intramedullary injection of saline solution, IOP(S)) recording. Lameness was assessed subjectively and using force plate gait analysis. Fluorochrome bone labeling was performed. Horses were euthanatized at 12 weeks. Navicular bone mineral density (BMD) was measured, and bone histology evaluated. Peak IOP (IOP(max)) after stress testing was significantly (P<.05) reduced immediately after core decompression; however, the magnitude of these effects was decreased at 3 and 6 weeks after decompression. A significant (P<.05) correlation existed between IOP(max) and BMD. No lameness was observed beyond the first week after surgery. Substantial remodeling and neovascularization was evident adjacent the surgery sites. Navicular bone core decompression surgery reduced IOP(max), and, with the exception of a mild short-lived lameness, caused no other adverse effects in healthy horses during the 12-week study period. © Copyright 2011 by The American College of Veterinary Surgeons.

Changes in optical coherence tomography measurements after orbital wall decompression in dysthyroid optic neuropathy.

PubMed

Park, Kyung-Ah; Kim, Yoon-Duck; Woo, Kyung In

2018-06-01

The purpose of our study was to assess changes in peripapillary retinal nerve fiber layer (RNFL) thickness after orbital wall decompression in eyes with dysthyroid optic neuropathy (DON). We analyzed peripapillary optical coherence tomography (OCT) images (Cirrus HD-OCT) from controls and patients with DON before and 1 and 6 months after orbital wall decompression. There was no significant difference in mean preoperative peripapillary retinal nerve fiber layer thickness between eyes with DON and controls. The superior and inferior peripapillary RNFL thickness decreased significantly 1 month after decompression surgery compared to preoperative values (p = 0.043 and p = 0.022, respectively). The global average, superior, temporal, and inferior peripapillary RNFL thickness decreased significantly 6 months after decompression surgery compared to preoperative values (p = 0.015, p = 0.028, p = 0.009, and p = 0.006, respectively). Patients with greater preoperative inferior peripapillary RNFL thickness tended to have better postoperative visual acuity at the last visit (p = 0.024, OR = 0.926). Our data revealed a significant decrease in peripapillary RNFL thickness postoperatively after orbital decompression surgery in patients with DON. We also found that greater preoperative inferior peripapillary RNFL thickness was associated with better visual outcomes. We suggest that RNFL thickness can be used as a prognostic factor for DON before decompression surgery.

Spaceflight Decompression Sickness Contingency Plan

NASA Technical Reports Server (NTRS)

Dervay, Joseph P.

2007-01-01

A viewgraph presentation on the Decompression Sickness (DCS) Contingency Plan for manned spaceflight is shown. The topics include: 1) Approach; 2) DCS Contingency Plan Overview; 3) Extravehicular Activity (EVA) Cuff Classifications; 4) On-orbit Treatment Philosophy; 5) Long Form Malfunction Procedure (MAL); 6) Medical Checklist; 7) Flight Rules; 8) Crew Training; 9) Flight Surgeon / Biomedical Engineer (BME) Training; and 10) DCS Emergency Landing Site.

Timing of Decompression in Patients With Acute Spinal Cord Injury: A Systematic Review

PubMed Central

Wilson, Jefferson R.; Tetreault, Lindsay A.; Kwon, Brian K.; Arnold, Paul M.; Mroz, Thomas E.; Shaffrey, Christopher; Harrop, James S.; Chapman, Jens R.; Casha, Steve; Skelly, Andrea C.; Holmer, Haley K.; Brodt, Erika D.; Fehlings, Michael G.

2017-01-01

strength of evidence). One of 3 studies found a shorter length of hospital stay associated with early surgical decompression. Of 3 studies reporting on safety, no significant differences in rates of complications (including mortality, neurologic deterioration, pneumonia or pressure ulcers) were noted between early and late decompression groups. Conclusions: Results surrounding the efficacy of early versus late decompressive surgery, as well as the quality of evidence available, were variable depending on the level of SCI, timing of follow-up, and specific outcome considered. Existing evidence supports improved neurological recovery among cervical SCI patients undergoing early surgery; however, evidence regarding remaining SCI populations and clinical outcomes was inconsistent. PMID:29164038

Mechanical characterization of alloys in extreme conditions of high strain rates and high temperature

NASA Astrophysics Data System (ADS)

Cadoni, Ezio

2018-03-01

The aim of this paper is the description of the mechanical characterization of alloys under extreme conditions of temperature and loading. In fact, in the frame of the Cost Action CA15102 “Solutions for Critical Raw Materials Under Extreme Conditions (CRM-EXTREME)” this aspect is crucial and many industrial applications have to consider the dynamic response of materials. Indeed, for a reduction and substitution of CRMs in alloys is necessary to design the materials and understand if the new materials behave better or if the substitution or reduction badly affect their performance. For this reason, a deep knowledge of the mechanical behaviour at high strain-rates of considered materials is required. In general, machinery manufacturing industry or transport industry as well as energy industry have important dynamic phenomena that are simultaneously affected by extended strain, high strain-rate, damage and pressure, as well as conspicuous temperature gradients. The experimental results in extreme conditions of high strain rate and high temperature of an austenitic stainless steel as well as a high-chromium tempered martensitic reduced activation steel Eurofer97 are presented.

Optimal timing of autologous cranioplasty after decompressive craniectomy in children.

PubMed

Piedra, Mark P; Thompson, Eric M; Selden, Nathan R; Ragel, Brian T; Guillaume, Daniel J

2012-10-01

The object of this study was to determine if early cranioplasty after decompressive craniectomy for elevated intracranial pressure in children reduces complications. Sixty-one consecutive cases involving pediatric patients who underwent autologous cranioplasty after decompressive craniectomy for raised intracranial pressure at a single academic children's hospital over 15 years were studied retrospectively. Sixty-one patients were divided into early (< 6 weeks; 28 patients) and late (≥ 6 weeks; 33 patients) cranioplasty cohorts. The cohorts were similar except for slightly lower age in the early (8.03 years) than the late (10.8 years) cranioplasty cohort (p < 0.05). Bone resorption after cranioplasty was significantly more common in the late (42%) than the early (14%) cranioplasty cohort (p < 0.05; OR 5.4). No other complication differed in incidence between the cohorts. After decompressive craniectomy for raised intracranial pressure in children, early (< 6 weeks) cranioplasty reduces the occurrence of reoperation for bone resorption, without altering the incidence of other complications.

Bilateral Ocular Decompression Retinopathy after Ahmed Valve Implantation for Uveitic Glaucoma

PubMed Central

Flores-Preciado, Javier; Ancona-Lezama, David Arturo; Valdés-Lara, Carlos Andrés; Díez-Cattini, Gian Franco; Coloma-González, Itziar

2016-01-01

Case Report We report the case of a 29-year-old man who underwent Ahmed valve implantation in both eyes as treatment for uveitic glaucoma, subsequently presenting with bilateral ocular decompression retinopathy in the postoperative period. Discussion Ocular decompression retinopathy is a rare complication of filtering surgery in patients with glaucoma; however, the course is benign in most cases, with spontaneous resolution of bleedings and improvement of visual acuity. PMID:27920718

Resolution of Tachyarrhythmia Following Posterior Fossa Decompression Surgery for Chiari Malformation Type I.

PubMed

Elia, Christopher; Brazdzionis, James; Tashjian, Vartan

2018-03-01

Chiari malformation (CM) type I commonly presents with symptoms such as tussive headaches, paresthesias, and, in severe cases, corticobulbar dysfunction. However, patients may present with atypical symptoms lending to the complexity in this patient population. We present a case of a CM patient presenting with atypical cardiac symptoms and arrhythmias, all of which resolved after surgical decompression. A 31-year-old female presented with atypical chest pain, palpitations, tachycardia, headaches, and dizziness for 2 years. Multiple antiarrhythmics and ultimately cardiac ablation procedure proved to be ineffective. Magnetic resonance imaging revealed CM, and the patient ultimately underwent surgical decompression with subsequent resolution of her symptoms. The surgical management of CM patients presenting with atypical symptoms can be challenging and often lead to delays in intervention. To our knowledge this is the only reported case of a patient presenting with tachyarrhythmia and atypical chest pain with resolution after Chiari decompression. We believe the dramatic improvement documented in the present case should serve to advance Chiari decompression in CM patients presenting with refractory tachyarrhythmia in whom no other discernable cause has been elucidated. Further studies are needed to better correlate the findings and to hopefully establish a criteria for patients that will likely benefit from surgical decompression. Copyright © 2017 Elsevier Inc. All rights reserved.

Critical Appraisal on Orbital Decompression for Thyroid Eye Disease: A Systematic Review and Literature Search.

PubMed

Boboridis, Konstadinos G; Uddin, Jimmy; Mikropoulos, Dimitrios G; Bunce, Catey; Mangouritsas, George; Voudouragkaki, Irini C; Konstas, Anastasios G P

2015-07-01

Orbital decompression is the indicated procedure for addressing exophthalmos and compressive optic neuropathy in thyroid eye disease. There are an abundance of techniques for removal of orbital bone, fat, or a combination published in the scientific literature. The relative efficacy and complications of these interventions in relation to the specific indications remain as yet undocumented. We performed a systematic review of the current published evidence for the effectiveness of orbital decompression, possible complications, and impact on quality of life. We searched the current databases for medical literature and controlled trials, oculoplastic textbooks, and conference proceedings to identify relevant data up to February 2015. We included randomized controlled trials (RCTs) comparing two or more interventions for orbital decompression. We identified only two eligible RCTs for inclusion in the review. As a result of the significant variability between studies on decompression, i.e., methodology and outcome measures, we did not perform a meta-analysis. One study suggests that the transantral approach and endonasal technique had similar effects in reducing exophthalmos but the latter is safer. The second study provides evidence that intravenous steroids may be superior to primary surgical decompression in the management of compressive optic neuropathy requiring less secondary surgical procedures. Most of the published literature on orbital decompression consists of retrospective, uncontrolled trials. There is evidence from those studies that removal of the medial and lateral wall (balanced) and the deep lateral wall decompression, with or without fat removal, may be the most effective surgical methods with only few complications. There is a clear unmet need for controlled trials evaluating the different techniques for orbital decompression. Ideally, future studies should address the effectiveness, possible complications, quality of life, and cost of each

Analysis of direct costs of decompressive craniectomy in victims of traumatic brain injury.

PubMed

Badke, Guilherme Lellis; Araujo, João Luiz Vitorino; Miura, Flávio Key; Guirado, Vinicius Monteiro de Paula; Saade, Nelson; Paiva, Aline Lariessy Campos; Avelar, Tiago Marques; Pedrozo, Charles Alfred Grander; Veiga, José Carlos Esteves

2018-04-01

Decompressive craniectomy is a procedure required in some cases of traumatic brain injury (TBI). This manuscript evaluates the direct costs and outcomes of decompressive craniectomy for TBI in a developing country and describes the epidemiological profile. A retrospective study was performed using a five-year neurosurgical database, taking a sample of patients with TBI who underwent decompressive craniectomy. Several variables were considered and a formula was developed for calculating the total cost. Most patients had multiple brain lesions and the majority (69.0%) developed an infectious complication. The general mortality index was 68.8%. The total cost was R$ 2,116,960.22 (US$ 661,550.06) and the mean patient cost was R$ 66,155.00 (US$ 20,673.44). Decompressive craniectomy for TBI is an expensive procedure that is also associated with high morbidity and mortality. This was the first study performed in a developing country that aimed to evaluate the direct costs. Prevention measures should be a priority.

Surgical decompression for space-occupying cerebral infarction (the Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial [HAMLET]): a multicentre, open, randomised trial.

PubMed

Hofmeijer, Jeannette; Kappelle, L Jaap; Algra, Ale; Amelink, G Johan; van Gijn, Jan; van der Worp, H Bart

2009-04-01

Patients with space-occupying hemispheric infarctions have a poor prognosis, with case fatality rates of up to 80%. In a pooled analysis of randomised trials, surgical decompression within 48 h of stroke onset reduced case fatality and improved functional outcome; however, the effect of surgery after longer intervals is unknown. The aim of HAMLET was to assess the effect of decompressive surgery within 4 days of the onset of symptoms in patients with space-occupying hemispheric infarction. Patients with space-occupying hemispheric infarction were randomly assigned within 4 days of stroke onset to surgical decompression or best medical treatment. The primary outcome measure was the modified Rankin scale (mRS) score at 1 year, which was dichotomised between good (0-3) and poor (4-6) outcome. Other outcome measures were the dichotomy of mRS score between 4 and 5, case fatality, quality of life, and symptoms of depression. Analysis was by intention to treat. This trial is registered, ISRCTN94237756. Between November, 2002, and October, 2007, 64 patients were included; 32 were randomly assigned to surgical decompression and 32 to best medical treatment. Surgical decompression had no effect on the primary outcome measure (absolute risk reduction [ARR] 0%, 95% CI -21 to 21) but did reduce case fatality (ARR 38%, 15 to 60). In a meta-analysis of patients in DECIMAL (DEcompressive Craniectomy In MALignant middle cerebral artery infarction), DESTINY (DEcompressive Surgery for the Treatment of malignant INfarction of the middle cerebral arterY), and HAMLET who were randomised within 48 h of stroke onset, surgical decompression reduced poor outcome (ARR 16%, -0.1 to 33) and case fatality (ARR 50%, 34 to 66). Surgical decompression reduces case fatality and poor outcome in patients with space-occupying infarctions who are treated within 48 h of stroke onset. There is no evidence that this operation improves functional outcome when it is delayed for up to 96 h after stroke onset

Predictive modeling of altitude decompression sickness in humans

NASA Technical Reports Server (NTRS)

Kenyon, D. J.; Hamilton, R. W., Jr.; Colley, I. A.; Schreiner, H. R.

1972-01-01

The coding of data on 2,565 individual human altitude chamber tests is reported as part of a selection procedure designed to eliminate individuals who are highly susceptible to decompression sickness, individual aircrew members were exposed to the pressure equivalent of 37,000 feet and observed for one hour. Many entries refer to subjects who have been tested two or three times. This data contains a substantial body of statistical information important to the understanding of the mechanisms of altitude decompression sickness and for the computation of improved high altitude operating procedures. Appropriate computer formats and encoding procedures were developed and all 2,565 entries have been converted to these formats and stored on magnetic tape. A gas loading file was produced.

Spinal decompression sickness: mechanical studies and a model.

PubMed

Hills, B A; James, P B

1982-09-01

Six experimental investigations of various mechanical aspects of the spinal cord are described relevant to its injury by gas deposited from solution by decompression. These show appreciable resistances to gas pockets dissipating by tracking along tissue boundaries or distending tissue, the back pressure often exceeding the probable blood perfusion pressure--particularly in the watershed zones. This leads to a simple mechanical model of spinal decompression sickness based on the vascular "waterfall" that is consistent with the pathology, the major quantitative aspects, and the symptomatology--especially the reversibility with recompression that is so difficult to explain by an embolic mechanism. The hypothesis is that autochthonous gas separating from solution in the spinal cord can reach sufficient local pressure to exceed the perfusion pressure and thus occlude blood flow.

Parameter estimation of the copernicus decompression model with venous gas emboli in human divers.

PubMed

Gutvik, Christian R; Dunford, Richard G; Dujic, Zeljko; Brubakk, Alf O

2010-07-01

Decompression Sickness (DCS) may occur when divers decompress from a hyperbaric environment. To prevent this, decompression procedures are used to get safely back to the surface. The models whose procedures are calculated from, are traditionally validated using clinical symptoms as an endpoint. However, DCS is an uncommon phenomenon and the wide variation in individual response to decompression stress is poorly understood. And generally, using clinical examination alone for validation is disadvantageous from a modeling perspective. Currently, the only objective and quantitative measure of decompression stress is Venous Gas Emboli (VGE), measured by either ultrasonic imaging or Doppler. VGE has been shown to be statistically correlated with DCS, and is now widely used in science to evaluate decompression stress from a dive. Until recently no mathematical model has existed to predict VGE from a dive, which motivated the development of the Copernicus model. The present article compiles a selection experimental dives and field data containing computer recorded depth profiles associated with ultrasound measurements of VGE. It describes a parameter estimation problem to fit the model with these data. A total of 185 square bounce dives from DCIEM, Canada, 188 recreational dives with a mix of single, repetitive and multi-day exposures from DAN USA and 84 experimentally designed decompression dives from Split Croatia were used, giving a total of 457 dives. Five selected parameters in the Copernicus bubble model were assigned for estimation and a non-linear optimization problem was formalized with a weighted least square cost function. A bias factor to the DCIEM chamber dives was also included. A Quasi-Newton algorithm (BFGS) from the TOMLAB numerical package solved the problem which was proved to be convex. With the parameter set presented in this article, Copernicus can be implemented in any programming language to estimate VGE from an air dive.

[Microvascular decompression for hemifacial spasm. Ten years of experience].

PubMed

Revuelta-Gutiérrez, Rogelio; Vales-Hidalgo, Lourdes Olivia; Arvizu-Saldaña, Emiliano; Hinojosa-González, Ramón; Reyes-Moreno, Ignacio

2003-01-01

Hemifacial spasm characterized by involuntary paroxistic contractions of the face is more frequent on left side and in females. Evolution is progressive and in a few cases may disappear. Management includes medical treatment, botulinum toxin, and microvascular decompression of the nerve. We present the results of 116 microvascular decompressions performed in 88 patients over 10 years. All patients had previous medical treatment. All patients were operated on with microsurgical technique by asterional craniotomy. Vascular compression was present in all cases with one exception. Follow-up was from 1 month to 133 months. Were achieved excellent results in 70.45% of cases after first operation, good results in 9.09%, and poor results in 20.45% of patients. Long-term results were excellent in 81.82%, good in 6.82%, and poor in 11.36% of patients. Hypoacusia and transitory facial palsy were the main complications. Hemifacial spasm is a painless but disabling entity. Medical treatment is effective in a limited fashion. Injection of botulinum toxin has good response but benefit is transitory. Microvascular decompression is treatment of choice because it is minimally invasive, not destructive, requires minimum technical support, and yields best long-term results.

Electromagnetic image-guided orbital decompression: technique, principles, and preliminary experience with 6 consecutive cases.

PubMed

Servat, Juan J; Elia, Maxwell Dominic; Gong, Dan; Manes, R Peter; Black, Evan H; Levin, Flora

2014-12-01

To assess the feasibility of routine use of electromagnetic image guidance systems in orbital decompression. Six consecutive patients underwent stereotactic-guided three wall orbital decompression using the novel Fusion ENT Navigation System (Medtronic), a portable and expandable electromagnetic guidance system with multi-instrument tracking capabilities. The system consists of the Medtronic LandmarX System software-enabled computer station, signal generator, field-generating magnet, head-mounted marker coil, and surgical tracking instruments. In preparation for use of the LandmarX/Fusion protocol, all patients underwent preoperative non-contrast CT scan from the superior aspect of the frontal sinuses to the inferior aspect of the maxillary sinuses that includes the nasal tip. The Fusion ENT Navigation System (Medtronic™) was used in 6 patients undergoing maximal 3-wall orbital decompression for Graves' orbitopthy after a minimum of six months of disease inactivity. Preoperative Hertel exophthalmometry measured more than 27 mm in all patients. The navigation system proved to be no more difficult technically than the traditional orbital decompression approach. Electromagnetic image guidance is a stereotactic surgical navigation system that provides additional intraoperative flexibility in orbital surgery. Electromagnetic image-guidance offers the ability to perform more aggressive orbital decompressions with reduced risk.

Evaluation of transcranial surgical decompression of the optic canal as a treatment option for traumatic optic neuropathy.

PubMed

He, Zhenhua; Li, Qiang; Yuan, Jingmin; Zhang, Xinding; Gao, Ruiping; Han, Yanming; Yang, Wenzhen; Shi, Xuefeng; Lan, Zhengbo

2015-07-01

Traumatic optic neuropathy (TON) is a serious complication of head trauma, with the incidence rate ranging from 0.5% to 5%. The two treatment options widely practiced for TON are: (i) high-dose corticosteroid therapy and (ii) surgical decompression. However, till date, there is no consensus on the treatment protocol. This study aimed to evaluate the therapeutic efficacy of transcranial decompression of optic canal in TON patients. A total of 39 patients with visual loss resulting from TON between January 2005 and June 2013 were retrospectively reviewed for preoperative vision, preoperative image, visual evoked potential (VEP), surgical approach, postoperative visual acuity, complications, and follow-up results. All these patients underwent transcranial decompression of optic canal. During the three-month follow-up period, among the 39 patients, 21 showed an improvement in their eyesight, 6 recovered to standard logarithmic visual acuity chart "visible," 10 could count fingers, 2 could see hand movement, and 3 regained light sensation. Visual evoked potential could be used as an important preoperative and prognostic evaluation parameter for TON patients. Once TON was diagnosed, surgery is a promising therapeutic option, especially when a VEP wave is detected, irrespective of the HRCT scan findings. Operative time between trauma and operation is not necessary reference to assess the therapeutic effect of surgical decompression. The poor results of this procedure may be related to the severity of optic nerve injury. The patient's age is an important factor affecting the surgical outcomes. Copyright © 2015 Elsevier B.V. All rights reserved.

Spontaneous extracranial decompression of epidural hematoma.

PubMed

Neely, John C; Jones, Blaise V; Crone, Kerry R

2008-03-01

Epidural hematoma (EDH) is a common sequela of head trauma in children. An increasing number are managed nonsurgically, with close clinical and imaging observation. We report the case of a traumatic EDH that spontaneously decompressed into the subgaleal space, demonstrated on serial CT scans that showed resolution of the EDH and concurrent enlargement of the subgaleal hematoma.

Experimental and computational studies on the femoral fracture risk for advanced core decompression.

PubMed

Tran, T N; Warwas, S; Haversath, M; Classen, T; Hohn, H P; Jäger, M; Kowalczyk, W; Landgraeber, S

2014-04-01

Two questions are often addressed by orthopedists relating to core decompression procedure: 1) Is the core decompression procedure associated with a considerable lack of structural support of the bone? and 2) Is there an optimal region for the surgical entrance point for which the fracture risk would be lowest? As bioresorbable bone substitutes become more and more common and core decompression has been described in combination with them, the current study takes this into account. Finite element model of a femur treated by core decompression with bone substitute was simulated and analyzed. In-vitro compression testing of femora was used to confirm finite element results. The results showed that for core decompression with standard drilling in combination with artificial bone substitute refilling, daily activities (normal walking and walking downstairs) are not risky for femoral fracture. The femoral fracture risk increased successively when the entrance point is located further distal. The critical value of the deviation of the entrance point to a more distal part is about 20mm. The study findings demonstrate that optimal entrance point should locate on the proximal subtrochanteric region in order to reduce the subtrochanteric fracture risk. Furthermore the consistent results of finite element and in-vitro testing imply that the simulations are sufficient. Copyright © 2014 Elsevier Ltd. All rights reserved.

21 CFR 884.5225 - Abdominal decompression chamber.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Abdominal decompression chamber. 884.5225 Section 884.5225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic...

21 CFR 884.5225 - Abdominal decompression chamber.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Abdominal decompression chamber. 884.5225 Section 884.5225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic...

21 CFR 884.5225 - Abdominal decompression chamber.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Abdominal decompression chamber. 884.5225 Section 884.5225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic...

21 CFR 884.5225 - Abdominal decompression chamber.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Abdominal decompression chamber. 884.5225 Section 884.5225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Obstetrical and Gynecological Therapeutic...

29 CFR Appendix A to Subpart S of... - Decompression Tables

Code of Federal Regulations, 2011 CFR

2011-07-01

... uniform rate from 4 pounds to 0-pound gage over a period of 40 minutes. Rate—0.10 pound per minute or 10.../pound Total time decompress minutes 14 1/2 1 14 4 2 0.20 6 2 4 0 4 1.00 6 1 1 14 4 2 0.20 6 2 4 0 4 1.00 6 11/2 1 14 4 2 0.20 6 2 4 0 4 1.00 6 2 1 14 4 2 0.20 6 2 4 0 4 1.00 6 3 1 14 4 2 0.20 6 2 4 0 4 1...

[Orbital decompression in Grave's disease: comparison of techniques].

PubMed

Sellari-Franceschini, S; Berrettini, S; Forli, F; Bartalena, L; Marcocci, C; Tanda, M L; Nardi, M; Lepri, A; Pinchera, A

1999-12-01

Grave's ophthalmopathy is an inflammatory, autoimmune disorder often associated with Grave's disease. The inflammatory infiltration involves the retrobulbar fatty tissue and the extrinsic eye muscles, causing proptosis, extraocular muscle dysfunction and often diplopia. Orbital decompression is an effective treatment in such cases, particularly when resistant to drugs and external radiation therapy. This work compares the results of orbital decompression performed by removing: a) the medial and lateral walls (Mourits technique) in 10 patients (19 orbits) and b) the medial and lower walls (Walsh-Ogura technique) in 17 patients (31 orbits). The results show that removing the floor of the orbit enables better reduction of proptosis but more easily leads to post-operative diplopia. Thus it proves necessary to combine the two techniques, modifying the surgical approach on a case-by-case basis.

Pharmacological intervention against bubble-induced platelet aggregation in a rat model of decompression sickness

PubMed Central

Vallée, Nicolas; Ignatescu, Mihaela; Bourdon, Lionel

2011-01-01

Decompression sickness (DCS) with alterations in coagulation system and formation of platelet thrombi occurs when a subject is subjected to a reduction in environmental pressure. Blood platelet consumption after decompression is clearly linked to bubble formation in humans and offers an index for evaluating DCS severity in animal models. Previous studies highlighted a predominant involvement of platelet activation and thrombin generation in bubble-induced platelet aggregation (BIPA). To study the mechanism of the BIPA in DCS, we examined the effect of acetylsalicylic acid (ASA), heparin (Hep), and clopidogrel (Clo), with anti-thrombotic dose pretreatment in a rat model of DCS. Male Sprague-Dawley rats (n = 208) were randomly assigned to one experimental group treated before the hyperbaric exposure and decompression protocol either with ASA (3×100 mg·kg−1·day−1, n = 30), Clo (50 mg·kg−1·day−1, n = 60), Hep (500 IU/kg, n = 30), or to untreated group (n = 49). Rats were first compressed to 1,000 kPa (90 msw) for 45 min and then decompressed to surface in 38 min. In a control experiment, rats were treated with ASA (n = 13), Clo (n = 13), or Hep (n = 13) and maintained at atmospheric pressure for an equivalent period of time. Onset of DCS symptoms and death were recorded during a 60-min observation period after surfacing. DCS evaluation included pulmonary and neurological signs. Blood samples for platelet count (PC) were taken 30 min before hyperbaric exposure and 30 min after surfacing. Clo reduces the DCS mortality risk (mortality rate: 3/60 with Clo, 15/30 with ASA, 21/30 with Hep, and 35/49 in the untreated group) and DCS severity (neurological DCS incidence: 9/60 with Clo, 6/30 with ASA, 5/30 with Hep, and 12/49 in the untreated group). Clo reduced fall in platelet count and BIPA (−4,5% with Clo, −19.5% with ASA, −19,9% with Hep, and −29,6% in the untreated group). ASA, which inhibits the thromboxane A2 pathway, and Hep, which inhibits thrombin

Decompressive hemicraniectomy in a space-occupying presentation of hemiconvulsion-hemiplegia-epilepsy syndrome.

PubMed

Berhouma, Moncef; Chekili, Ridha; Brini, Ines; Kchir, Nidhameddine; Jemel, Hafedh; Bousnina, Souad; Khaldi, Moncef

2007-12-01

A case of an acute life-threatening presentation of hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome requiring an urgent decompressive hemicraniectomy is described. A 9 month-old baby had a status epilepticus following a sustained fever, leading to a comatose state and a right pupillary dilatation associated with a left hemiplegia. The MRI showed a swelling right hemisphere with marked temporal herniation. The baby underwent a decompressive right hemicraniectomy with temporal cortical biopsies. The post-operative course was favourable. The histological findings were unspecific, showing a gliotic spongiosis with disseminated granular cells. The post-operative MRI depicted a right hemisphere atrophy. To our knowledge, a space-occupying presentation of HHE syndrome requiring surgical decompression has never been described before while only a few reports dealt with the neuropathological aspects of this syndrome.

Chiari decompression outcomes using ligamentum nuchae harvest and duraplasty in pediatric patients with Chiari malformation type I.

PubMed

Cools, Michael J; Quinsey, Carolyn S; Elton, Scott W

2018-04-13

OBJECTIVE The choice of graft material for duraplasty in decompressions of Chiari malformations remains a matter of debate. The authors present a detailed technique for harvesting ligamenta nuchae, as well as the clinical and radiographic outcomes of this technique, in a case series. METHODS The authors conducted a retrospective study evaluating the outcomes of Chiari malformation type I decompression and duraplasty in children aged 0-18 years at a single institution from 2013 to 2016. They collected both intraoperative and postoperative variables and compared them qualitatively to published data. RESULTS During the study period, the authors performed 25 Chiari malformation decompressions with ligamentum nuchae graft duraplasties. Of the 25 patients, 10 were females, and the mean age at surgery was 8.6 years (range 13 months to 18 years). The median operative time was 163 minutes (IQR 152-187 minutes), with approximately 10 minutes needed by a resident surgeon to harvest the graft. The mean length of stay was 3 nights (range 2-6 nights), and the mean follow-up was 12.6 months (range 0.5-43.5 months). One patient (4%) developed a CSF leak that was repaired using an oversewing patch. There were no postoperative pseudomeningoceles or infections. Of the 19 patients presenting with a syrinx, imaging showed improvement in 10 (53%) and 8 (42%) had stable syrinx size on imaging. Of 16 patients presenting with a symptomatic Chiari malformation, 14 (87.5%) experienced resolution of symptoms and in 1 (4%) symptoms remained the same. One patient (4%) presented with worsening syrinx and symptoms 1.5 months after initial surgery and underwent repeat decompression. CONCLUSIONS The authors describe a series of clinical and imaging outcomes of patients who underwent Chiari malformation decompression and duraplasty with a harvested ligamentum nuchae. The rates of postoperative CSF leak are similar to established techniques of autologous and artificial grafts, with similarly

"White Cord Syndrome" of Acute Hemiparesis After Posterior Cervical Decompression and Fusion for Chronic Cervical Stenosis.

PubMed

Antwi, Prince; Grant, Ryan; Kuzmik, Gregory; Abbed, Khalid

2018-05-01

"White cord syndrome" is a very rare condition thought to be due to acute reperfusion of chronically ischemic areas of the spinal cord. Its hallmark is the presence of intramedullary hyperintense signal on T2-weighted magnetic resonance imaging sequences in a patient with unexplained neurologic deficits following spinal cord decompression surgery. The syndrome is rare and has been reported previously in 2 patients following anterior cervical decompression and fusion. We report an additional case of this complication. A 68-year-old man developed acute left-sided hemiparesis after posterior cervical decompression and fusion for cervical spondylotic myelopathy. The patient improved with high-dose steroid therapy. The rare white cord syndrome following either anterior cervical decompression and fusion or posterior cervical decompression and fusion may be due to ischemic-reperfusion injury sustained by chronically compressed parts of the spinal cord. In previous reports, patients have improved following steroid therapy and acute rehabilitation. Copyright © 2018 Elsevier Inc. All rights reserved.

Elimination of CT-detected gas bubbles derived from decompression illness with abdominal symptoms after a short hyperbaric oxygen treatment in a monoplace chamber: a case report.

PubMed

Oyaizu, Takuya; Enomoto, Mitsuhiro; Tsujimoto, Toshihide; Kojima, Yasushi; Okawa, Atsushi; Yagishita, Kazuyoshi

2017-01-01

We report the case of a 54-year-old male compressed-air worker with gas bubbles detected by computed tomography (CT). He had complained of strong abdominal pain 30 minutes after decompression after working at a pressure equivalent to 17 meters of sea water for three hours. The initial CT images revealed gas bubbles in the intrahepatic portal vein, pulmonary artery and bilateral femoral vein. After the first hyperbaric oxygen treatment (HBO₂ at 2.5 atmospheres absolute/ATA for 150 minutes), no bubbles were detected on repeat CT examination. The patient still exhibited abdominal distension, mild hypesthesia and slight muscle weakness in the upper extremities. Two sessions of U.S. Navy Treatment Table 6 (TT6) were performed on Days 6 and 7 after onset. The patient recovered completely on Day 7. This report describes the important role of CT imaging in evaluating intravascular gas bubbles as well as eliminating the diagnosis of other conditions when divers or compressed-air workers experience uncommon symptoms of decompression illness. In addition, a short treatment table of HBO₂ using non-TT6 HBO₂ treatment may be useful to reduce gas bubbles and the severity of decompression illness in emergent cases. Copyright© Undersea and Hyperbaric Medical Society.

Cost-effectiveness of surgical decompression for space-occupying hemispheric infarction.

PubMed

Hofmeijer, Jeannette; van der Worp, H Bart; Kappelle, L Jaap; Eshuis, Sara; Algra, Ale; Greving, Jacoba P

2013-10-01

Surgical decompression reduces mortality and increases the probability of a favorable functional outcome after space-occupying hemispheric infarction. Its cost-effectiveness is uncertain. We assessed clinical outcomes, costs, and cost-effectiveness for the first 3 years in patients who were randomized to surgical decompression or best medical treatment within 48 hours after symptom onset in the Hemicraniectomy After Middle Cerebral Artery Infarction With Life-Threatening Edema Trial (HAMLET). Data on medical consumption were derived from case record files, hospital charts, and general practitioners. We calculated costs per quality-adjusted life year (QALY). Uncertainty was assessed with bootstrapping. A Markov model was constructed to estimate costs and health outcomes after 3 years. Of 39 patients enrolled within 48 hours, 21 were randomized to surgical decompression. After 3 years, 5 surgical (24%) and 14 medical patients (78%) had died. In the first 3 years after enrollment, operated patients had more QALYs than medically treated patients (mean difference, 1.0 QALY [95% confidence interval, 0.6-1.4]), but at higher costs (mean difference, €127,000 [95% confidence interval, 73,100-181,000]), indicating incremental costs of €127,000 per QALY gained. Ninety-eight percent of incremental cost-effectiveness ratios replicated by bootstrapping were >€80,000 per QALY gained. Markov modeling suggested costs of ≈€60,000 per QALY gained for a patient's lifetime. Surgical decompression for space-occupying infarction results in an increase in QALYs, but at very high costs. http://www.controlled-trials.com. Unique identifier: ISRCTN94237756.

Minimally Invasive Transtubular Endoscopic Decompression for L5 Radiculopathy Induced by Lumbosacral Extraforaminal Lesions

PubMed Central

Kitamura, Takahiro; Masuda, Keigo; Hotta, Kensuke; Senba, Hideyuki; Shidahara, Satoshi

2018-01-01

Study Design Retrospective study. Purpose This study aimed to evaluate the efficacy of minimally invasive transtubular endoscopic decompression for the treatment of lumbosacral extraforaminal lesion (LSEFL). Overview of Literature Conventional procedures for surgical decompression for the treatment of LSEFL involve certain technical challenges because the lumbosacral extraforaminal region has unique anatomical features. Moreover, the efficacy of minimally invasive procedures performed via the posterolateral approach for LSEFL has been reported. Methods Twenty-five patients who had undergone minimally invasive transtubular endoscopic decompression for the treatment of LSEFL and could be followed up for at least 1 year postoperatively were enrolled. Five of these patients had a history of lumbar surgery, and seven had concomitant adjacent-level spinal stenosis. The clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) lumbar score, numeric rating scale (NRS), and the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The mean postoperative follow-up (FU) duration was 3.8 years. Results All procedures could be completed without any severe surgical complications, and all patients could resume their previous activity level within 1 month postoperatively. The JOA score significantly increased from 14.1±4.0 at baseline to 23.1±3.7 at the 1-year FU and 22.1±3.8 at the last FU. Similarly, there were significant improvements in the postoperative NRS and JOABPEQ scores. An additional surgery was performed in two patients (8%) during the FU period. Patients with degenerative scoliosis exhibited significantly poorer outcomes compared with those without this condition. Conclusions Transtubular endoscopic decompression can overcome certain technical challenges involved in the conventional procedures for LSEFL treatment; therefore, it can be recommended as a useful procedure for treating LSEFL. This procedure can provide some benefits to LSEFL

A rare remote epidural hematoma secondary to decompressive craniectomy.

PubMed

Xu, Gang-Zhu; Wang, Mao-De; Liu, Kai-Ge; Bai, Yin-An

2014-01-01

Remote epidural hematoma (REDH) is an uncommon complication of decompressive craniectomy. Remote epidural hematomas of the parietal occiput region have been reported only rarely. We report a unique case of delayed-onset bilateral extensive straddle postsagittal sinus and bilateral lateral sinus parietal occiput REDH after decompressive craniectomy, of which volume was approximately 130 mL, with left deviating midline structures. The patient was immediately taken back to the operating room for evacuation of the REDH via bilateral parietal and occiput craniectomy. Postoperatively, serial computed tomographic scans performed 3 days later showed that the REDH had been completely evacuated. Two months later, the patient regained full consciousness and obtained a near-complete recovery except for right facial paralysis.

A case of decompression sickness in a commercial pilot.

PubMed

Wolf, C W; Petzl, D H; Seidl, G; Burghuber, O C

1989-10-01

We report a case of decompression sickness (DCS) followed by pulmonary edema in a 47-year-old commercial pilot who operated a non-pressurized turboprop twin at flight level 290. He became unconscious and recovered after an emergency descent. The pilot collapsed and a pulmonary edema occurred 8 h after landing. The patient improved rapidly with fluid replacement and without hyperbaric therapy, which was not available at that time. This course of DCS is unusual because it is reported that fluid replacement without hyperbaric therapy normally cannot recover severe cases of DCS. The considerable increase in body weight of this pilot within the last 6 months may have been a predisposing factor for development of decompression sickness.

A current review of core decompression in the treatment of osteonecrosis of the femoral head.

PubMed

Pierce, Todd P; Jauregui, Julio J; Elmallah, Randa K; Lavernia, Carlos J; Mont, Michael A; Nace, James

2015-09-01

The review describes the following: (1) how traditional core decompression is performed, (2) adjunctive treatments, (3) multiple percutaneous drilling technique, and (4) the overall outcomes of these procedures. Core decompression has optimal outcomes when used in the earliest, precollapse disease stages. More recent studies have reported excellent outcomes with percutaneous drilling. Furthermore, adjunct treatment methods combining core decompression with growth factors, bone morphogenic proteins, stem cells, and bone grafting have demonstrated positive results; however, larger randomized trial is needed to evaluate their overall efficacy.

Farris-Tang retractor in optic nerve sheath decompression surgery.

PubMed

Spiegel, Jennifer A; Sokol, Jason A; Whittaker, Thomas J; Bernard, Benjamin; Farris, Bradley K

2016-01-01

Our purpose is to introduce the use of the Farris-Tang retractor in optic nerve sheath decompression surgery. The procedure of optic nerve sheath fenestration was reviewed at our tertiary care teaching hospital, including the use of the Farris-Tang retractor. Pseudotumor cerebri is a syndrome of increased intracranial pressure without a clear cause. Surgical treatment can be effective in cases in which medical therapy has failed and disc swelling with visual field loss progresses. Optic nerve sheath decompression surgery (ONDS) involves cutting slits or windows in the optic nerve sheath to allow cerebrospinal fluid to escape, reducing the pressure around the optic nerve. We introduce the Farris-Tang retractor, a retractor that allows for excellent visualization of the optic nerve sheath during this surgery, facilitating the fenestration of the sheath and visualization of the subsequent cerebrospinal fluid egress. Utilizing a medial conjunctival approach, the Farris-Tang retractor allows for easy retraction of the medial orbital tissue and reduces the incidence of orbital fat protrusion through Tenon's capsule. The Farris-Tang retractor allows safe, easy, and effective access to the optic nerve with good visualization in optic nerve sheath decompression surgery. This, in turn, allows for greater surgical efficiency and positive patient outcomes.

Decompression management by 43 models of dive computer: single square-wave exposures to between 15 and 50 metres' depth.

PubMed

Sayer, Martin D J; Azzopardi, Elaine; Sieber, Arne

2014-12-01

Dive computers are used in some occupational diving sectors to manage decompression but there is little independent assessment of their performance. A significant proportion of occupational diving operations employ single square-wave pressure exposures in support of their work. Single examples of 43 models of dive computer were compressed to five simulated depths between 15 and 50 metres' sea water (msw) and maintained at those depths until they had registered over 30 minutes of decompression. At each depth, and for each model, downloaded data were used to collate the times at which the unit was still registering "no decompression" and the times at which various levels of decompression were indicated or exceeded. Each depth profile was replicated three times for most models. Decompression isopleths for no-stop dives indicated that computers tended to be more conservative than standard decompression tables at depths shallower than 30 msw but less conservative between 30-50 msw. For dives requiring decompression, computers were predominantly more conservative than tables across the whole depth range tested. There was considerable variation between models in the times permitted at all of the depth/decompression combinations. The present study would support the use of some dive computers for controlling single, square-wave diving by some occupational sectors. The choice of which makes and models to use would have to consider their specific dive management characteristics which may additionally be affected by the intended operational depth and whether staged decompression was permitted.

21 CFR 884.5225 - Abdominal decompression chamber.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Abdominal decompression chamber. 884.5225 Section 884.5225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... abdominal pain during pregnancy or labor. (b) Classification. Class III (premarket approval). (c) Date PMA...

Early Versus Delayed Surgical Decompression of Spinal Cord after Traumatic Cervical Spinal Cord Injury: A Cost-Utility Analysis.

PubMed

Furlan, Julio C; Craven, B Catharine; Massicotte, Eric M; Fehlings, Michael G

2016-04-01

This cost-utility analysis was undertaken to compare early (≤24 hours since trauma) versus delayed surgical decompression of spinal cord to determine which approach is more cost effective in the management of patients with acute traumatic cervical spinal cord injury (SCI). This study includes the patients enrolled into the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS) and admitted at Toronto Western Hospital. Cases were grouped into patients with motor complete SCI and individuals with motor incomplete SCI. A cost-utility analysis was performed for each group of patients by the use of data for the first 6 months after SCI. The perspective of a public health care insurer was adopted. Costs were estimated in 2014 U.S. dollars. Utilities were estimated from the STASCIS. The baseline analysis indicates early spinal decompression is more cost-effective approach compared with the delayed spinal decompression. When we considered the delayed spinal decompression as the baseline strategy, the incremental cost-effectiveness ratio analysis revealed a saving of US$ 58,368,024.12 per quality-adjusted life years gained for patients with complete SCI and a saving of US$ 536,217.33 per quality-adjusted life years gained in patients with incomplete SCI for the early spinal decompression. The probabilistic analysis confirmed the early-decompression strategy as more cost effective than the delayed-decompression approach, even though there is no clearly dominant strategy. The results of this economic analysis suggests that early decompression of spinal cord was more cost effective than delayed surgical decompression in the management of patients with motor complete and incomplete SCI, even though no strategy was clearly dominant. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparing cost-effectiveness of X-Stop with minimally invasive decompression in lumbar spinal stenosis: a randomized controlled trial.

PubMed

Lønne, Greger; Johnsen, Lars Gunnar; Aas, Eline; Lydersen, Stian; Andresen, Hege; Rønning, Roar; Nygaard, Øystein P

2015-04-15

Randomized clinical trial with 2-year follow-up. To compare the cost-effectiveness of X-stop to minimally invasive decompression in patients with symptomatic lumbar spinal stenosis. Lumbar spinal stenosis is the most common indication for operative treatment in elderly. Although surgery is more costly than nonoperative treatment, health outcomes for more than 2 years were shown to be significantly better. Surgical treatment with minimally invasive decompression is widely used. X-stop is introduced as another minimally invasive technique showing good results compared with nonoperative treatment. We enrolled 96 patients aged 50 to 85 years, with symptoms of neurogenic intermittent claudication within 250-m walking distance and 1- or 2-level lumbar spinal stenosis, randomized to either minimally invasive decompression or X-stop. Quality-adjusted life-years were based on EuroQol EQ-5D. The hospital unit costs were estimated by means of the top-down approach. Each cost unit was converted into a monetary value by dividing the overall cost by the amount of cost units produced. The analysis of costs and health outcomes is presented by the incremental cost-effectiveness ratio. The study was terminated after a midway interim analysis because of significantly higher reoperation rate in the X-stop group (33%). The incremental cost for X-stop compared with minimally invasive decompression was &OV0556;2832 (95% confidence interval: 1886-3778), whereas the incremental health gain was 0.11 quality-adjusted life-year (95% confidence interval: -0.01 to 0.23). Based on the incremental cost and effect, the incremental cost-effectiveness ratio was &OV0556;25,700. The majority of the bootstrap samples displayed in the northeast corner of the cost-effectiveness plane, giving a 50% likelihood that X-stop is cost-effective at the extra cost of &OV0556;25,700 (incremental cost-effectiveness ratio) for a quality-adjusted life-year. The significantly higher cost of X-stop is mainly due to

Decompression sickness after air break in prebreathe described with a survival model.

PubMed

Conkin, Johnny

2011-06-01

A perception exists in aerospace that a brief interruption in a 100% oxygen prebreathe (PB) by breathing air has a substantial decompression sickness (DCS) consequence. The consequences of an air break during PB on the subsequent hypobaric DCS outcomes were evaluated. The hypothesis was that asymmetrical and not symmetrical nitrogen (N2) kinetics was best to model the distribution of subsequent DCS survival times after PBs that included air breaks. DCS survival times from 95 controls for a 60-min PB prior to 2- or 4-h exposures to 4.37 psia (9144 m; 30,000 ft) were analyzed along with 3 experimental conditions: 10-min air break (N = 40), 20-min air break (N = 40), or 60-min air break (N = 32) 30 min into the PB followed by 30 min of PB. Ascent rate was 1524 m x min(-1) and all 207 exposures included light exercise at 4.37 psia. Various computations of decompression dose were evaluated; either the difference or ratio of P1N2 and P2, where P1N2 was computed tissue N2 pressure to account for the PB and P2 was altitude pressure. Survival times were described with an accelerated log logistic model with asymmetrical N2 kinetics defining P1N2--P2 as best decompression dose. Exponential N2 uptake during the air break was described with a 10-min half time and N2 elimination during PB with a 60-min half time. A simple conclusion about compensation for air break is not possible because the duration and location of a break in a PB is variable. The resulting survival model is used to compute additional PB time to compensate for an air break in PB within the range of tested conditions.

Does decompression of odontogenic cysts and cystlike lesions change the histologic diagnosis?

PubMed

Schlieve, Thomas; Miloro, Michael; Kolokythas, Antonia

2014-06-01

The purpose of this study was to report the histopathologic findings after postdecompression definitive treatment of odontogenic cystlike lesions and determine whether the diagnosis was consistent with the pretreatment diagnosis, thereby answering the clinical question: does decompression change the histologic diagnosis? The authors implemented a retrospective cohort study from a sample of patients diagnosed with a benign odontogenic cystlike lesion and who underwent decompression followed by definitive surgery as part of their treatment. The predictor variable was treatment by decompression and the dependent variable was change in histologic diagnosis. Age, gender, and lesion location were included as variables. The χ(2) test was used for statistical analysis of the categorical data and P values less than .05 were considered statistically significant. Twenty-five cysts and cystlike lesions in 25 patients were treated with decompression followed by enucleation and curettage. The mean age was 34 years (range, 13 to 80 yr) and 56% (14) were male patients. Lesions were located in the mandible in 76% (19 of 25) of patients. Postdecompression histologic examination at the time of definitive surgical treatment was consistent with the preoperative biopsy diagnosis in 91% (10 of 11) of keratocystic odontogenic tumors, 67% (2 of 3) of glandular odontogenic cysts, 75% (3 of 4) of dentigerous cysts, and 100% (7 of 7) of cystic ameloblastomas. The histologic diagnosis at time of definitive treatment by enucleation and curettage is consistent with the predecompression diagnosis. Therefore, all lesions should be definitively treated after decompression based on the initial lesion diagnosis, with all patients placed on appropriate follow-up protocols. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. All rights reserved.

Factors associated with spinal fusion after posterior fossa decompression in pediatric patients with Chiari I malformation and scoliosis.

PubMed

Mackel, Charles E; Cahill, Patrick J; Roguski, Marie; Samdani, Amer F; Sugrue, Patrick A; Kawakami, Noriaki; Sturm, Peter F; Pahys, Joshua M; Betz, Randal R; El-Hawary, Ron; Hwang, Steven W

2016-12-01

OBJECTIVE The authors performed a study to identify clinical characteristics of pediatric patients diagnosed with Chiari I malformation and scoliosis associated with a need for spinal fusion after posterior fossa decompression when managing the scoliotic curve. METHODS The authors conducted a multicenter retrospective review of 44 patients, aged 18 years or younger, diagnosed with Chiari I malformation and scoliosis who underwent posterior fossa decompression from 2000 to 2010. The outcome of interest was the need for spinal fusion after decompression. RESULTS Overall, 18 patients (40%) underwent posterior fossa decompression alone, and 26 patients (60%) required a spinal fusion after the decompression. The mean Cobb angle at presentation and the proportion of patients with curves > 35° differed between the decompression-only and fusion cohorts (30.7° ± 11.8° vs 52.1° ± 26.3°, p = 0.002; 5 of 18 vs 17 of 26, p = 0.031). An odds ratio of 1.0625 favoring a need for fusion was established for each 1° of increase in Cobb angle (p = 0.012, OR 1.0625, 95% CI 1.0135-1.1138). Among the 14 patients older than 10 years of age with a primary Cobb angle exceeding 35°, 13 (93%) ultimately required fusion. Patients with at least 1 year of follow-up whose curves progressed more 10° after decompression were younger than those without curve progression (6.1 ± 3.0 years vs 13.7 ± 3.2 years, p = 0.001, Mann-Whitney U-test). Left apical thoracic curves constituted a higher proportion of curves in the decompression-only group (8 of 16 vs 1 of 21, p = 0.002). CONCLUSIONS The need for fusion after posterior fossa decompression reflected the curve severity at clinical presentation. Patients presenting with curves measuring > 35°, as well as those greater than 10 years of age, may be at greater risk for requiring fusion after posterior fossa decompression, while patients less than 10 years of age may require routine monitoring for curve progression. Left apical thoracic curves

Dibutyryl cAMP effects on thromboxane and leukotriene production in decompression-induced lung injury

NASA Technical Reports Server (NTRS)

Little, T. M.; Butler, B. D.

1997-01-01

Decompression-induced venous bubble formation has been linked to increased neutrophil counts, endothelial cell injury, release of vasoactive eicosanoids, and increased vascular membrane permeability. These actions may account for inflammatory responses and edema formation. Increasing the intracellular cAMP has been shown to decrease eicosanoid production and edema formation in various models of lung injury. Reduction of decompression-induced inflammatory responses was evaluated in decompressed rats pretreated with saline (controls) or dibutyryl cAMP (DBcAMP, an analog of cAMP). After pretreatment, rats were exposed to either 616 kPa for 120 min or 683 kPa for 60 min. The observed increases in extravascular lung water ratios (pulmonary edema), bronchoalveolar lavage, and pleural protein in the saline control group (683 kPa) were not evident with DBcAMP treatment. DBcAMP pretreatment effects were also seen with the white blood cell counts and the percent of neutrophils in the bronchoalveolar lavage. Urinary levels of thromboxane B2, 11-dehydrothromboxane B2, and leukotriene E4 were significantly increased with the 683 kPa saline control decompression exposure. DBcAMP reduced the decompression-induced leukotriene E4 production in the urine. Plasma levels of thromboxane B2, 11-dehydrothromboxane B2, and leukotriene E4 were increased with the 683-kPa exposure groups. DBcAMP treatment did not affect these changes. The 11-dehydrothromboxane B2 and leukotriene E4 levels in the bronchoalveolar lavage were increased with the 683 kPa exposure and were reduced with the DBcAMP treatment. Our results indicate that DBcAMP has the capability to reduce eicosanoid production and limit membrane permeability and subsequent edema formation in rats experiencing decompression sickness.

Delayed, disequilibrium degassing in rhyolite magma: Decompression experiments and implications for explosive volcanism

USGS Publications Warehouse

Mangan, M.; Sisson, T.

2000-01-01

Recent numerical models and analog shock tube experiments show that disequilibrium degassing during magma ascent may lead to violent vesiculation very near the surface. In this study a series of decompression experiments using crystal-free, rhyolite melt were conducted to examine the development of large supersaturations due to delayed, homogenous (spontaneous) bubble nucleation. Melts were saturated at 900??C and 200 MPa with either 5.2 wt% dissolved H2O, or with 4.2 wt% H2O and 640 ppm CO2, and isothermally decompressed at linear rates of either 0.003, 0.025, or 8.5 MPa/s to final pressures between 25 and 175 MPa. Additional isobaric saturation experiments (900??C, 200-25 MPa) using pure H2O or mixed H2O-CO2 fluids establish reference equilibrium solubility curves/values. Homogenous nucleation is triggered in both H2O-only and H2O-CO2 experiments once the supersaturation pressure (??Pss) reaches ?? 120-150 MPa and the melt contains ?? two times its equilibrium water contents. Bubble number density and nucleation rate depend on the supersaturation pressure, with values on the order of 102/cm3 and < 1/cm3/s for ??Pss~120 MPa; 106/cm3 and 103-105/cm3/s for ??Pss??~130-150 MPa; and 107/cm3 and 106/cm3/s for ??Pss??160-175 MPa. Nucleation rates are consistent with classical nucleation theory, and infer an activation energy for nucleation of 1.5 x 10-18 J/nucleus, a critical bubble radius of 2 x 10-9 m, and an effective surface tension for rhyolite at 5.2 wt% H2O and 900??C of 0.10-0.11 N/m. The long nucleation delay limits the time available for subsequent diffusion such that disequilibrium dissolved H2O and CO2 contents persist to the end of our runs. The disequilibrium degassing paths inferred from our experiments contrast markedly with the equilibrium or quasi-equilibrium paths found in other studies where bubble nucleation occurs heterogenously on crystals or other discontinuities in the melt at low ??Pss. Homogenous and heterogenous nucleation rates are

Reduction in high-frequency hearing loss following technical modifications to microvascular decompression for hemifacial spasm.

PubMed

Thirumala, Parthasarathy; Frederickson, Andrew M; Balzer, Jeffrey; Crammond, Donald; Habeych, Miguel E; Chang, Yue-Fang; Sekula, Raymond F

2015-10-01

Microvascular decompression is a safe and effective procedure to treat hemifacial spasm, but the operation poses some risk to the patient's hearing. While severe sensorineural hearing loss across all frequencies occurs at a low rate in experienced hands, a recent study suggests that as many as one-half of patients who undergo this procedure may experience ipsilateral high-frequency hearing loss (HFHL), and as many as one-quarter may experience contralateral HFHL. While it has been suggested that drill-related noise may account for this finding, this study was designed to examine the effect of a number of techniques designed to protect the vestibulocochlear nerve from operative manipulation on the incidence of HFHL. Pure-tone audiometry was performed both preoperatively and postoperatively on 67 patients who underwent microvascular decompression for hemifacial spasm during the study period. A change of greater than 10 dB at either 4 kHz or 8 kHz was considered to be HFHL. Additionally, the authors analyzed intraoperative brainstem auditory evoked potentials from this patient cohort. The incidence of ipsilateral HFHL in this cohort was 7.4%, while the incidence of contralateral HFHL was 4.5%. One patient (1.5%; also included in the HFHL group) experienced an ipsilateral nonserviceable hearing loss. The reduced incidence of HFHL in this study suggests that technical modifications including performing the procedure without the use of fixed retraction may greatly reduce, but not eliminate, the occurrence of HFHL following microvascular decompression for hemifacial spasm.

Physiological consequences of rapid or prolonged aircraft decompression: evaluation using a human respiratory model.

PubMed

Wolf, Matthew

2014-04-01

Aircraft passengers and crew may be subjected to rapid or prolonged decompression to high cabin altitude when an aircraft develops a hole in the fuselage. The accepted measure of neurological damage due to the hypobaric hypoxia produced is the subjective 'time of useful consciousness' (TUC) measure, which is appropriate for pilots and crew who perform their given tasks, however, TUC is measured under conditions different than the decompression scenarios that passengers undergo in today's aircraft. Ernsting proposed that prolonged exposure to alveolar O2 pressures less than 30 mmHg (P30) causes neurological damage. The current study proposes that a critical value of arterial O2 saturation of 70% (S70) can be used in place of P30 and that this physiological measure is more suited for determination of hypobaric hypoxia in passengers. The study shows the equivalence of model-predicted P30 and S70 values in the Ernsting-decompression scenarios. The model is also used to predict values of these physiological measures in actual aircraft-decompression scenarios. The model can be used by others to quantitatively predict the degree of hypobaric hypoxia for virtually any kind of decompression scenario, including those where supplemental O2 is used. Use of this tool avoids the prohibitive costs of human-subject testing for new aircraft and the potential danger inherent in such tests.

Gender not a factor for altitude decompression sickness risk

NASA Technical Reports Server (NTRS)

Webb, James T.; Kannan, Nandini; Pilmanis, Andrew A.

2003-01-01

INTRODUCTION: Early, retrospective reports of the incidence of altitude decompression sickness (DCS) during altitude chamber training exposures indicated that women were more susceptible than men. We hypothesized that a controlled, prospective study would show no significant difference. METHODS: We conducted 25 altitude chamber decompression exposure profiles. A total of 291 human subjects, 197 men and 94 women, underwent 961 exposures to simulated altitude for up to 8 h, using zero to 4 h of preoxygenation. Throughout the exposures, subjects breathed 100% oxygen, rested or performed mild or strenuous exercise, and were monitored for precordial venous gas emboli (VGE) and DCS symptoms. RESULTS: No significant differences in DCS incidence were observed between men (49.5%) and women (45.3%). However, VGE occurred at significantly higher rates among men than women under the same exposure conditions, 69.3% and 55.0% respectively. Women using hormonal contraception showed significantly greater susceptibility to DCS than those not using hormonal contraception during the latter two weeks of the menstrual cycle. Significantly higher DCS incidence was observed in the heaviest men, in women with the highest body fat, and in subjects with the highest body mass indices and lowest levels of fitness. CONCLUSION: No differences in altitude DCS incidence were observed between the sexes under our test conditions, although men developed VGE more often than women. Age and height showed no significant influence on DCS incidence, but persons of either sex with higher body mass index and lower physical fitness developed DCS more frequently.

White matter changes linked to visual recovery after nerve decompression

PubMed Central

Paul, David A.; Gaffin-Cahn, Elon; Hintz, Eric B.; Adeclat, Giscard J.; Zhu, Tong; Williams, Zoë R.; Vates, G. Edward; Mahon, Bradford Z.

2015-01-01

The relationship between the integrity of white matter tracts and cortical function in the human brain remains poorly understood. Here we use a model of reversible white matter injury, compression of the optic chiasm by tumors of the pituitary gland, to study the structural and functional changes that attend spontaneous recovery of cortical function and visual abilities after surgical tumor removal and subsequent decompression of the nerves. We show that compression of the optic chiasm leads to demyelination of the optic tracts, which reverses as quickly as 4 weeks after nerve decompression. Furthermore, variability across patients in the severity of demyelination in the optic tracts predicts visual ability and functional activity in early cortical visual areas, and pre-operative measurements of myelination in the optic tracts predicts the magnitude of visual recovery after surgery. These data indicate that rapid regeneration of myelin in the human brain is a significant component of the normalization of cortical activity, and ultimately the recovery of sensory and cognitive function, after nerve decompression. More generally, our findings demonstrate the utility of diffusion tensor imaging as an in vivo measure of myelination in the human brain. PMID:25504884

Navigation-guided optic canal decompression for traumatic optic neuropathy: Two case reports.

PubMed

Bhattacharjee, Kasturi; Serasiya, Samir; Kapoor, Deepika; Bhattacharjee, Harsha

2018-06-01

Two cases of traumatic optic neuropathy presented with profound loss of vision. Both cases received a course of intravenous corticosteroids elsewhere but did not improve. They underwent Navigation guided optic canal decompression via external transcaruncular approach, following which both cases showed visual improvement. Postoperative Visual Evoked Potential and optical coherence technology of Retinal nerve fibre layer showed improvement. These case reports emphasize on the role of stereotactic navigation technology for optic canal decompression in cases of traumatic optic neuropathy.

The Impact of Metastatic Spinal Tumor Location on 30-Day Perioperative Mortality and Morbidity After Surgical Decompression.

PubMed

Hussain, Awais K; Vig, Khushdeep S; Cheung, Zoe B; Phan, Kevin; Lima, Mauricio C; Kim, Jun S; Kaji, Deepak A; Arvind, Varun; Cho, Samuel Kang-Wook

2018-06-01

A retrospective cohort study from 2011 to 2014 was performed using the American College of Surgeons National Surgical Quality Improvement Program database. The purpose of this study was to assess the impact of tumor location in the cervical, thoracic, or lumbosacral spine on 30-day perioperative mortality and morbidity after surgical decompression of metastatic extradural spinal tumors. Operative treatment of metastatic spinal tumors involves extensive procedures that are associated with significant complication rates and healthcare costs. Past studies have examined various risk factors for poor clinical outcomes after surgical decompression procedures for spinal tumors, but few studies have specifically investigated the impact of tumor location on perioperative mortality and morbidity. We identified 2238 patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent laminectomy for excision of metastatic extradural tumors in the cervical, thoracic, or lumbosacral spine. Baseline patient characteristics were collected from the database. Univariate and multivariate regression analyses were performed to examine the association between spinal tumor location and 30-day perioperative mortality and morbidity. On univariate analysis, cervical spinal tumors were associated with the highest rate of pulmonary complications. Multivariate regression analysis demonstrated that cervical spinal tumors had the highest odds of multiple perioperative complications. However, thoracic spinal tumors were associated with the highest risk of intra- or postoperative blood transfusion. In contrast, patients with metastatic tumors in the lumbosacral spine had lower odds of perioperative mortality, pulmonary complications, and sepsis. Tumor location is an independent risk factor for perioperative mortality and morbidity after surgical decompression of metastatic spinal tumors. The addition of tumor location to existing prognostic scoring

Ambulation Increases Decompression Sickness in Spacewalk Simulations

NASA Technical Reports Server (NTRS)

Pollock, N. W.; Natoli, M. J.; Conkin, J.; Wessel, J. H., III; Gernhardt, M. L.

2014-01-01

Musculoskeletal activity has the potential to both improve and compromise decompression safety. Exercise enhances inert gas elimination during oxygen breathing prior to decompression (prebreathe), but it may also promote bubble nuclei formation (nucleation), which can lead to gas phase separation and bubble growth and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of musculoskeletal activity and the level of tissue supersaturation may be critical to the net effect. Understanding the relationships is important to evaluate exercise prebreathe protocols and quantify decompression risk in gravity and microgravity environments. Data gathered during NASA's Prebreathe Reduction Program (PRP) studies combined oxygen prebreathe and exercise followed by low pressure (4.3 psi; altitude equivalent of 30,300 ft [9,235 m]) microgravity simulation to produce two protocols used by astronauts preparing for extravehicular activity. Both the Phase II/CEVIS (cycle ergometer vibration isolation system) and ISLE (in-suit light exercise) trials eliminated ambulation to more closely simulate the microgravity environment. The CEVIS results (35 male, 10 female) serve as control data for this NASA/Duke study to investigate the influence of ambulation exercise on bubble formation and the subsequent risk of DCS. METHODS Four experiments will replicate the CEVIS exercise-enhanced oxygen prebreathe protocol, each with a different exception. The first of these is currently underway. Experiment 1 - Subjects complete controlled ambulation (walking in place with fixed cadence and step height) during both preflight and at 4.3 psi instead of remaining nonambulatory throughout. Experiment 2 - Subjects remain non-ambulatory during the preflight period and ambulatory at 4.3 psi. Experiment 3 - Subjects ambulate during the preflight period and remain non-ambulatory at 4.3 psi. Experiment 4 - The order of heavy and light exercise employed in the CEVIS protocol is

Dynamics of upper mantle rocks decompression melting above hot spots under continental plates

NASA Astrophysics Data System (ADS)

Perepechko, Yury; Sorokin, Konstantin; Sharapov, Victor

2014-05-01

Numeric 2D simulation of the decompression melting above the hot spots (HS) was accomplished under the following conditions: initial temperature within crust mantle section was postulated; thickness of the metasomatized lithospheric mantle is determined by the mantle rheology and position of upper asthenosphere boundary; upper and lower boundaries were postulated to be not permeable and the condition for adhesion and the distribution of temperature (1400-2050°C); lateral boundaries imitated infinity of layer. Sizes and distribution of lateral points, their symmetry, and maximum temperature varied between the thermodynamic condition for existences of perovskite - majorite transition and its excess above transition temperature. Problem was solved numerically a cell-vertex finite volume method for thermo hydrodynamic problems. For increasing convergence of iterative process the method of lower relaxation with different value of relaxation parameter for each equation was used. The method of through calculation was used for the increase in the computing rate for the two-layered upper mantle - lithosphere system. Calculated region was selected as 700 x (2100-4900) km. The time step for the study of the asthenosphere dynamics composed 0.15-0.65 Ma. The following factors controlling the sizes and melting degree of the convective upper mantle, are shown: a) the initial temperature distribution along the section of upper mantleb) sizes and the symmetry of HS, c) temperature excess within the HS above the temperature on the upper and lower mantle border TB=1500-2000oC with 5-15% deviation but not exceed 2350oC. It is found, that appearance of decompression melting with HS presence initiate primitive mantle melting at TB > of 1600oC. Initial upper mantle heating influence on asthenolens dimensions with a constant HS size is controlled mainly by decompression melting degree. Thus, with lateral sizes of HS = 400 km the decompression melting appears at TB > 1600oC and HS

Patient-specific core decompression surgery for early-stage ischemic necrosis of the femoral head

PubMed Central

Wang, Wei; Hu, Wei; Yang, Pei; Dang, Xiao Qian; Li, Xiao Hui; Wang, Kun Zheng

2017-01-01

Introduction Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests. Methods Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target). Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT). A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy. Results The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm. Conclusions Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis. PMID:28464029

Patient-specific core decompression surgery for early-stage ischemic necrosis of the femoral head.

PubMed

Wang, Wei; Hu, Wei; Yang, Pei; Dang, Xiao Qian; Li, Xiao Hui; Wang, Kun Zheng

2017-01-01

Core decompression is an efficient treatment for early stage ischemic necrosis of the femoral head. In conventional procedures, the pre-operative X-ray only shows one plane of the ischemic area, which often results in inaccurate drilling. This paper introduces a new method that uses computer-assisted technology and rapid prototyping to enhance drilling accuracy during core decompression surgeries and presents a validation study of cadaveric tests. Twelve cadaveric human femurs were used to simulate early-stage ischemic necrosis. The core decompression target at the anterolateral femoral head was simulated using an embedded glass ball (target). Three positioning Kirschner wires were drilled into the top and bottom of the large rotor. The specimen was then subjected to computed tomography (CT). A CT image of the specimen was imported into the Mimics software to construct a three-dimensional model including the target. The best core decompression channel was then designed using the 3D model. A navigational template for the specimen was designed using the Pro/E software and manufactured by rapid prototyping technology to guide the drilling channel. The specimen-specific navigation template was installed on the specimen using positioning Kirschner wires. Drilling was performed using a guide needle through the guiding hole on the templates. The distance between the end point of the guide needle and the target was measured to validate the patient-specific surgical accuracy. The average distance between the tip of the guide needle drilled through the guiding template and the target was 1.92±0.071 mm. Core decompression using a computer-rapid prototyping template is a reliable and accurate technique that could provide a new method of precision decompression for early-stage ischemic necrosis.

Ambulation During Periods of Supersaturation Increase Decompression Stress in Spacewalk Simulations

NASA Technical Reports Server (NTRS)

Pollock, N. W.; Natoli, M. J.; Martina, S. D.; Conkin, J.; Wessel, J. H., III; Gernhardt, M. L.

2016-01-01

Musculoskeletal activity accelerates inert gas elimination during oxygen breathing prior to decompression (prebreathe), but may also promote bubble formation (nucleation) and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of musculoskeletal activity and the level of tissue supersaturation are likely critical to the net effect. Understanding the relationships is important to evaluate exercise prebreathe protocols and quantify decompression risk in gravity and microgravity environments. The NASA Prebreathe Reduction Program (PRP) combined oxygen prebreathe and exercise preceding a low pressure (4.3 psia; altitude equivalent of 30,300 ft [9,235 m]) simulation exposure of non-ambulatory subjects (a microgravity analog) to produce two protocols now used by astronauts preparing for extravehicular activity. One protocol included both upright cycling and non-cycling exercise (CEVIS: 'cycle ergometer vibration isolation system') and one protocol relied on non-cycling exercise only (ISLE: 'in-suit light exercise'). CEVIS trial data serve as control data for the current study to investigate the influence of ambulation exercise in 1G environments on bubble formation and the subsequent risk of DCS.

The influence of prior exercise at anaerobic threshold on decompression sickness

NASA Technical Reports Server (NTRS)

Kumar, K. V.; Waligora, James M.; Gilbert, John H., III

1992-01-01

This study was conducted to examine the effects of exercise prior to decompression on the incidence of altitude decompression sickness (DCS). In a balanced, two-period, crossover trial, 39 healthy individuals were each exposed twice, without denitrogenation, to an altitude of 6400 m in a hypobaric chamber. Under the experimental condition, subjects exercised at their predetermined anaerobic threshold levels for 30 min each day for 3 d prior to altitude exposure; the other condition was a non-exercise control. Under both conditions, subjects performed exercise simulating space extravehicular activities at altitude for a period of 3 h, while breathing 100 percent oxygen. There were nine preferences (untied responses) for DCS, four under control and five under experimental conditions; all were Type I, pain-only bends. No carry-over effects between exposures was detected, and the test for treatment differences showed p = 0.56 for symptoms. No significant difference in DCS preferences was found after subjects exercised up to their anaerobic threshold levels during the days prior to decompression.

Space Flight Decompression Sickness Contingency Plan

NASA Technical Reports Server (NTRS)

Dervay, Joseph; Gernhardt, Michael L.; Ross, Charles E.; Hamilton, Douglas; Homick, Jerry L. (Technical Monitor)

2000-01-01

The purpose was to develop an enhanced plan to diagnose, treat, and manage decompression sickness (DCS) during extravehicular activity (EVA). This plan is merited by the high frequency of upcoming EVAs necessary to construct and maintain the International Space Station (ISS). The upcoming ISS era will demand a significant increase in EVA. The DCS Risk and Contingency Plan provided a new and improved approach to DCS reporting, treatment, management, and training.

Management of sinonasal complications after endoscopic orbital decompression for Graves' orbitopathy.

PubMed

Antisdel, Jastin L; Gumber, Divya; Holmes, Janalee; Sindwani, Raj

2013-09-01

Endoscopic orbital decompression (EnOD) has proven to be safe and effective for the treatment of Graves' orbitopathy; however, complications do occur. Although the literature focuses on orbital complications, sinonasal complications including postobstructive sinusitis, hemorrhage, and cerebrospinal fluid (CSF) leak can also be challenging to manage. This study examines the incidence and management of sinonasal complications in these patients. Retrospective review. Clinical data, surgical findings, and postoperative outcomes were reviewed of patients who underwent EnOD for Graves' disease between March 2004 and November 2010. The incidence and management of postoperative sinonasal complications requiring an intervention were examined. The study group consisted of 50 consecutive patients (86 decompression procedures): 11 males and 39 females with an average age of 48.6 years (SD = 12.9). Incidence of significant sinonasal complications was 3.5% (5/86): with one patient experiencing postoperative hemorrhage requiring operative management, three patients with postoperative obstructive sinusitis, and one patient with nasal obstruction secondary to nasal adhesions that required lysis. The maxillary sinus was the most commonly involved and was managed using the mega-antrostomy technique. In the case of frontal sinusitis, an endoscopic transaxillary approach was utilized to avoid injury to decompressed orbital contents. All complications were successfully managed without sequelae. Sinonasal complications following EnOD are uncommon. In the setting of a decompressed orbit, even routine types of postoperative issues can be challenging and require additional considerations. Successful management of postoperative sinusitis related to outflow obstruction may require more extensive approaches and novel techniques. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Safety of supramesocolic surgery in patients with portal cavernoma without portal vein decompression. Large single centre experience.

PubMed

Dokmak, Safi; Aussilhou, Béatrice; Sauvanet, Alain; Lévy, Philippe; Plessier, Aurélie; Ftériche, Fadhel S; Farges, Olivier; Vilgrain, Valérie; Valla, Dominique C; Belghiti, Jacques

2016-07-01

Supra-mesocolic surgery (SMS) is complicated in patients with portal vein cavernoma (PC) and portal decompression is recommended. The aim of this study was to report a large single centre of SMS in patients with PC without portal decompression. Between 2006 and 2013, all patients who met inclusion criteria were analyzed retrospectively. The primary endpoint was the feasibility rate, surgical and postoperative outcome. The secondary endpoints were the long-term outcome of patients who underwent biliary bypass for cholangitis. Risk factors for complications were studied. Thirty patients underwent 51 procedures. Pancreatitis was the main etiology of PC (19/30) and biliary obstruction was mainly related to the underlying disease and not to portal cholangiopathy (12/14). All planned procedures were successfully completed. Fourteen patients underwent biliary bypass. Median blood loss (250 ml), transfusion (n = 7), mortality (n = 0), overall morbidity (n = 12) and the median hospital stay (10 days). Good long-term control of cholangitis was achieved in the 9 patients alive with available follow-up. Significant risk factors for complications were a previous abdominal wall scar, previous intra-abdominal surgical field and liver fibrosis. SMS can be safely performed in patients with PC. In patients with risk factors for complications, portal decompression should be discussed. Copyright © 2016 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

Perfluorocarbon in Delayed Recompression with a Mixed Gender Swine Model of Decompression Sickness.

PubMed

Cronin, William A; Hall, Aaron A; Auker, Charles R; Mahon, Richard T

2018-01-01

Perfluorocarbons (PFC) are fluorinated hydrocarbons that dissolve gases to a much greater degree than plasma and hold promise in treating decompression sickness (DCS). The efficacy of PFC in a mixed gender model of DCS and safety in recompression therapy has not been previously explored. Swine (25 kg; N = 104; 51 male and 53 female) were randomized into normal saline solution (NSS) or PFC emulsion treatment groups and subjected to compression on air in a hyperbaric chamber at 200 fsw for 31 min. Then the animals were decompressed and observed for signs of DCS. Afterwards, they were treated with oxygen and either PFC (4 cc · kg-1) or NSS (4 cc · kg-1). Surviving animals were observed for 4 h, at which time they underwent recompression therapy using a standard Navy Treatment Table 6. After 24 h the animals were assessed and then euthanized. Survival rates were not significantly different between NSS (74.04%) and PFC (66.67%) treatment groups. All swine that received recompression treatment survived to the end of the study and no seizures were observed in either PFC or NSS animals. Within the saline treated swine group there were no significant differences in DCS survival between male (75.00%, N = 24) and female (73.08%, N = 26) swine. Within the PFC treated swine, survival of females (51.85%, N = 27) was significantly lower than males (81.48%, N = 27). In this large animal mixed gender efficacy study in DCS, PFC did not improve mortality or spinal cord injury, but appears safe during recompressive therapy. Gender differences in DCS treatment with PFC will need further study.Cronin WA, Hall AA, Auker CR, Mahon RT. Perfluorocarbon in delayed recompression with a mixed gender swine model of decompression sickness. Aerosp Med Hum Perform. 2018; 89(1):14-18.

Needle decompression in a patient with vision-threatening orbital emphysema

PubMed Central

Lin, Che-Yu; Tsai, Chieh-Chih; Kao, Shu-Ching; Kau, Hui-Chuan; Lee, Fenq-Lih

2016-01-01

Orbital emphysema is a condition resulting from trapping of air in loose subcutaneous or orbital tissues from the paranasal sinuses. This condition commonly seen in patients with a history of periorbital trauma or surgery, especially following sneezing or nose blowing. It usually has a benign and self-limited course. However, the entrapped orbital air can cause a substantial increase in pressure with restricted ocular motility or vascular compromise and become severe enough to cause visual impairment. We herein present the case of a patient who developed severe orbital emphysema after blunt trauma followed by sneezing and was successfully treated with needle decompression of intraorbital air. Emergency needle decompression resulted in an improvement in vision and intraocular pressure. PMID:29018719

Application of COMPONT Medical Adhesive Glue for Tension-Reduced Duraplasty in Decompressive Craniotomy

PubMed Central

Zhou, Yujia; Wang, Gesheng; Liu, Jialin; Du, Yong; Wang, Lei; Wang, Xiaoyong

2016-01-01

Background The aim of this study was to evaluate the application of medical adhesive glue for tension-reduced duraplasty in decompressive craniotomy. Material/Methods A total of 56 cases were enrolled for this study from Jan 2013 to May 2015. All patients underwent decompressive craniotomy and the dura was repaired in all of them with tension-reduced duraplasty using the COMPONT medical adhesive to glue artificial dura together. The postoperative complications and the healing of dura mater were observed and recorded. Results No wound infection, epidural or subdural hematoma, cerebrospinal fluid leakage, or other complications associated with the procedure occurred, and there were no allergic reactions to the COMPONT medical adhesive glue. The second-phase surgery of cranioplasty was performed at 3 to 6 months after the decompressive craniotomy in 32 out of the 56 cases. During the cranioplasty we observed no adherence of the artificial dura mater patch to the skin flap, no residual COMPONT glue, or hydropic or contracture change of tissue at the surgical sites. Additionally, no defect or weakening of the adherence between the artificial dura mater patch and the self dura matter occurred. Conclusions COMPONT medical adhesive glue is a safe and reliable tool for tension-reduced duraplasty in decompressive craniotomy. PMID:27752035

Mid- to long-term outcomes of posterior decompression with instrumented fusion for thoracic ossification of the posterior longitudinal ligament.

PubMed

Koda, Masao; Furuya, Takeo; Okawa, Akihiko; Inada, Taigo; Kamiya, Koshiro; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Yamazaki, Masashi; Aramomi, Masaaki; Ikeda, Osamu; Mannoji, Chikato

2016-05-01

Posterior decompression with instrumented fusion (PDF) surgery has been previously reported as a relatively safe surgical procedure for any type of thoracic ossification of the longitudinal ligament (OPLL). However, mid- to long-term outcomes are still unclear. The aim of the present study was to elucidate the mid- to long-term clinical outcome of PDF surgery for thoracic OPLL patients. The present study included 20 patients who had undergone PDF for thoracic OPLL and were followed for at least 5years. Increment change and recovery rate of the Japanese Orthopaedic Association (JOA) score were assessed. Revision surgery during the follow-up period was also recorded. Average JOA scores were 3.5 preoperatively and 7.1 at final follow-up. The average improvement in JOA score was 3.8 points and the average recovery rate was 47.0%. The JOA score showed gradual increase after surgery, and took 9months to reach peak recovery. As for neurological complications, two patients suffered postoperative paralysis, but both recovered without intervention. Six revision surgeries in four patients were related to OPLL. Additional anterior thoracic decompression for remaining ossification at the same level of PDF surgery was performed in one patient. Decompression surgery for deterioration of symptoms of pre-existing cervical OPLL was performed in three patients. One patient had undergone lumbar and cervical PDF surgery for de novo ossification foci of the lumbar and cervical spine. PDF surgery for thoracic OPLL is thus considered a relatively safe and stable surgical procedure considering the mid- to long-term outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microsurgical Decompression of Inferior Alveolar Nerve After Endodontic Treatment Complications.

PubMed

Bianchi, Bernardo; Ferri, Andrea; Varazzani, Andrea; Bergonzani, Michela; Sesenna, Enrico

2017-07-01

Iatrogenic injury in oral surgery is the most frequent cause of sensory disturbance in the distribution of the inferior alveolar nerve (IAN) and mental nerve.Inferior alveolar nerve damage can occur during third molar extraction, implant location, orthognathic surgery, preprosthetic surgery, salivary gland surgery, local anesthetic injections or during the resection of benign or malignant tumors.Injuries to the IAN can be caused also by endodontic treatment of mandibular molars and premolars when filling material is forced into the tooth and mandibular canal.The sensory disturbances that could follow a damage of the IAN could be hypoesthesia, dysesthesia, hyperesthesia, anesthesia, and sometimes a painful anesthesia that strike ipsilateral lower lip, chin, and teeth. These can undermine life quality by affecting speech, chewing, and social interaction.Treatment of these complications is sometimes difficult and could consist in observation or in surgical decompression of the involved nerve to relieve the patient's symptoms and improve sensory recovery. The most debated points are the timing of intervention and the effective role of decompression in clinical outcome-improvement.The purpose of this article is to show authors' experience with 2 patients treated with microsurgical nerve decompression to remove endodontic material from the mandibular canal and providing also a comprehensive review of the literature.

[Posterior decompression of the craniovertebral junction in syringomyelia combined with Chiari-1 malformation in children].

PubMed

Sanakoeva, A V; Korshunov, A E; Kadyrov, Sh U; Khukhlaeva, E A; Kushel', Yu V

to develop the algorithm for defining the amount of posterior decompression of the craniovertebral junction in children with syringomyelia combined with Chiari-1 malformation. Sixty eight children with syringomyelia and Chiari-1 malformation, under age of 18 years, underwent posterior decompression of the craniovertebral junction (PDCVJ) in the period from January 2001 to June 2016. Seven (10%) patients underwent extradural decompression (EDD), 16 (24%) patients underwent extra-arachnoid duraplasty (EAD), 25 (37%) patients underwent intra-arachnoid dissection (IAD) and duraplasty, and 20 (29%) patients underwent PDCVJ and placement of a fourth ventricle-subarachnoid shunt. Clinical improvement occurred in 85% of patients, and stabilization was observed in 11% of patients. Syringomyelia regressed in 78% of cases. There were no complications associated with EDD; however, re-operation was required in 3 (43%) cases. In the case of EAD, treatment results were satisfactory in 11 (79%) patients; re-operation was required in 2 (12.5%) cases; there were no complications in the early postoperative period. The highest complication rate of 6 (30%) cases was associated with shunt placement and duraplasty. However, long-term results in this group of patients were satisfactory in 16 (94%) cases, and MRI-based positive changes were observed in 100% of cases. According to our analysis, EAD is the method of choice for PDCVJ in children with syringomyelia and Chiari-1 malformation without myelopathy symptoms. In the presence of myelopathy symptoms, intra-arachnoid dissection (with or without shunting) is an acceptable alternative. To our opinion, the use of EDD in syringomyelia is unadvisable.

Evaluation of operative procedures for symptomatic outcome after decompression surgery for Chiari type I malformation.

PubMed

Kalb, Samuel; Perez-Orribo, Luis; Mahan, Mark; Theodore, Nicholas; Nakaji, Peter; Bristol, Ruth E

2012-09-01

The wide spectrum of symptoms and radiographic findings in patients with Chiari I malformation makes the decision to proceed with intervention controversial. We evaluated symptomatic outcomes using diverse surgical techniques in 104 patients who underwent decompression surgery. The symptoms of most patients improved. Patients with syringomyelia showed less symptomatic improvement; however, syringomyelia was not associated with postoperative symptomatic worsening. Durotomy was performed in 97.1% and arachnoid opening was performed in 60.6% with visualization of the fourth ventricle in 51.9% of patients. Neither arachnoid opening nor fourth ventricle visualization was associated with the clinical outcome. Duraplasty was performed in 94.2% of patients. A Chiari plate was used in 13.4% of patients and was associated with favorable outcomes. Use of postoperative steroids or muscle relaxants was not associated with outcome. Syringomyelia showed a 62.5% improvement rate on postoperative MRI. In conclusion, bony decompression and dural opening are important aspects of Chiari I surgery, with symptomatic improvement observed in most patients. Copyright © 2012. Published by Elsevier Ltd.

Long-term Outcome of Multiple Small-diameter Drilling Decompression Combined with Hip Arthroscopy versus Drilling Alone for Early Avascular Necrosis of the Femoral Head.

PubMed

Li, Ji; Li, Zhong-Li; Zhang, Hao; Su, Xiang-Zheng; Wang, Ke-Tao; Yang, Yi-Meng

2017-06-20

Avascular necrosis of femoral head (AVNFH) typically presents in the young adults and progresses quickly without proper treatments. However, the optimum treatments for early stage of AVNFH are still controversial. This study was conducted to evaluate the therapeutic effects of multiple small-diameter drilling decompression combined with hip arthroscopy for early AVNFH compared to drilling alone. This is a nonrandomized retrospective case series study. Between April 2006 and November 2010, 60 patients (98 hips) with early stage AVNFH participated in this study. The patients underwent multiple small-diameter drilling decompression combined with hip arthroscopy in 26 cases/43 hips (Group A) or drilling decompression alone in 34 cases/55 hips (Group B). Patients were followed up at 6, 12, and 24 weeks, and every 6 months thereafter. Radiographs were taken at every follow-up, Harris scores were recorded at the last follow-up, the paired t-test was used to compare the postoperative Harris scores. Surgery effective rate of the two groups was compared using the Chi-square test. All patients were followed up for an average of 57.6 months (range: 17-108 months). Pain relief and improvement of hip function were assessed in all patients at 6 months after the surgery. At the last follow-up, Group A had better outcome with mean Harris' scores improved from 68.23 ± 11.37 to 82.07 ± 2.92 (t = -7.21, P = 0.001) than Group B with mean Harris' scores improved from 69.46 ± 9.71 to 75.79 ± 4.13 (t = -9.47, P = 0.037) (significantly different: t = -2.54, P = 0.017). The total surgery effective rate was also significantly different between Groups A and B (86.0% vs. 74.5%; χ2 = 3.69, P = 0.02). For early stage of AVNFH, multiple small-diameter drilling decompression combined with hip arthroscopy is more effective than drilling decompression alone.

Long-term Outcome of Multiple Small-diameter Drilling Decompression Combined with Hip Arthroscopy versus Drilling Alone for Early Avascular Necrosis of the Femoral Head

PubMed Central

Li, Ji; Li, Zhong-Li; Zhang, Hao; Su, Xiang-Zheng; Wang, Ke-Tao; Yang, Yi-Meng

2017-01-01

Background: Avascular necrosis of femoral head (AVNFH) typically presents in the young adults and progresses quickly without proper treatments. However, the optimum treatments for early stage of AVNFH are still controversial. This study was conducted to evaluate the therapeutic effects of multiple small-diameter drilling decompression combined with hip arthroscopy for early AVNFH compared to drilling alone. Methods: This is a nonrandomized retrospective case series study. Between April 2006 and November 2010, 60 patients (98 hips) with early stage AVNFH participated in this study. The patients underwent multiple small-diameter drilling decompression combined with hip arthroscopy in 26 cases/43 hips (Group A) or drilling decompression alone in 34 cases/55 hips (Group B). Patients were followed up at 6, 12, and 24 weeks, and every 6 months thereafter. Radiographs were taken at every follow-up, Harris scores were recorded at the last follow-up, the paired t-test was used to compare the postoperative Harris scores. Surgery effective rate of the two groups was compared using the Chi-square test. Results: All patients were followed up for an average of 57.6 months (range: 17–108 months). Pain relief and improvement of hip function were assessed in all patients at 6 months after the surgery. At the last follow-up, Group A had better outcome with mean Harris’ scores improved from 68.23 ± 11.37 to 82.07 ± 2.92 (t = −7.21, P = 0.001) than Group B with mean Harris’ scores improved from 69.46 ± 9.71 to 75.79 ± 4.13 (t = –9.47, P = 0.037) (significantly different: t = –2.54, P = 0.017). The total surgery effective rate was also significantly different between Groups A and B (86.0% vs. 74.5%; χ2 = 3.69, P = 0.02). Conclusion: For early stage of AVNFH, multiple small-diameter drilling decompression combined with hip arthroscopy is more effective than drilling decompression alone. PMID:28584206

Preoperative retrolisthesis as a predictive risk factor of reoperation due to delayed-onset symptomatic foraminal stenosis after central decompression for lumbar canal stenosis without fusion.

PubMed

Ikegami, Daisuke; Hosono, Noboru; Mukai, Yoshihiro; Tateishi, Kosuke; Fuji, Takeshi

2017-08-01

For patients diagnosed with lumbar central canal stenosis with asymptomatic foraminal stenosis (FS), surgeons occasionally only decompress central stenosis and preserve asymptomatic FS. These surgeries have the potential risk of converting preoperative asymptomatic FS into symptomatic FS postoperatively by accelerating spinal degeneration, which requires reoperation. However, little is known about delayed-onset symptomatic FS postoperatively. This study aimed to evaluate the rate of reoperation for delayed-onset symptomatic FS after lumbar central canal decompression in patients with preoperative asymptomatic FS, and determine the predictive risk factors of those reoperations. This study is a retrospective cohort study. Two hundred eight consecutive patients undergoing posterior central decompression for lumbar canal stenosis between January 2009 and June 2014 were included in this study. The number of patients who had preoperative FS and the reoperation rate for delayed-onset symptomatic FS at the index levels were the outcome measures. Patients were divided into two groups with and without preoperative asymptomatic FS at the decompressed levels. The baseline characteristics and revision rates for delayed-onset symptomatic FS were compared between the two groups. Predictive risk factors for such reoperations were determined using multivariate logistic regression and receiver operating characteristics analyses. Preoperatively, 118 patients (56.7%) had asymptomatic FS. Of those, 18 patients (15.3%) underwent reoperation for delayed-onset symptomatic FS at a mean of 1.9 years after the initial surgery. Posterior slip in neutral position and posterior extension-neutral translation were significant risk factors for reoperation due to FS. The optimal cutoff values of posterior slip in neutral position and posterior extension-neutral translation for predicting the occurrence of such reoperations were both 1 mm; 66.7% of patients who met both of these cutoff values had

Rapid versus gradual bladder decompression in acute urinary retention.

PubMed

Etafy, Mohamed H; Saleh, Fatma H; Ortiz-Vanderdys, Cervando; Hamada, Alaa; Refaat, Alaa M; Aal, Mohamed Abdel; Deif, Hazem; Gawish, Maher; Abdellatif, Ashraf H; Gadalla, Khaled

2017-01-01

To demonstrate a benefit in diminished adverse events such as hypotension and hematuria with gradual drainage of the bladder when compared to rapid decompression in patients with acute urinary retention (AUR) due to benign prostatic hyperplasia in a case-control study. Sixty-two patients matched our selection criteria presenting with AUR. They were divided into two groups - the first was managed by rapid drainage of the bladder, the second was managed by gradual drainage through a urethral catheter (The first 100 mL immediately evacuated, then the rest evacuated gradually over 2 h). The mean age was 64.4 and 63.2 years in the first and second group, respectively. Diagnosed cause was benign hyperplasia of the prostate. Hematuria occurred in two patients in the first group and none in the second group. The two cases of hematuria were mild and treated conservatively. After the relief of the obstruction, the mean blood pressure was noticed to decrease by 15 mmHg and 10 mmHg in the first and second group, respectively, however, no one developed significant hypotension. Pain relief was achieved after complete drainage in the first group and after the evacuation of 100 mL in the second group. We conclude that there is no significant difference between rapid and gradual decompression of the bladder in patients with AUR. Hematuria and hypotension may occur after rapid decompression of the obstructed urinary bladder, but these complications are rarely clinically significant.

Report on computation of repetitive hyperbaric-hypobaric decompression tables

NASA Technical Reports Server (NTRS)

Edel, P. O.

1975-01-01

The tables were constructed specifically for NASA's simulated weightlessness training program; they provide for 8 depth ranges covering depths from 7 to 47 FSW, with exposure times of 15 to 360 minutes. These tables were based up on an 8 compartment model using tissue half-time values of 5 to 360 minutes and Workmanline M-values for control of the decompression obligation resulting from hyperbaric exposures. Supersaturation ratios of 1.55:1 to 2:1 were used for control of ascents to altitude following such repetitive dives. Adequacy of the method and the resultant tables were determined in light of past experience with decompression involving hyperbaric-hypobaric interfaces in human exposures. Using these criteria, the method showed conformity with empirically determined values. In areas where a discrepancy existed, the tables would err in the direction of safety.

Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

PubMed Central

Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

2015-01-01

Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s−1 is generated at 22.3 eV, with 5 × 10−5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications. PMID:26067922

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.

Propranolol Effects on Decompression Sickness in a Simulated DISSUB Rescue in Swine.

PubMed

Forbes, Angela S; Regis, David P; Hall, Aaron A; Mahon, Richard T; Cronin, William A

2017-04-01

Disabled submarine (DISSUB) survivors may face elevated CO2 levels and inert gas saturation, putting them at risk for CO2 toxicity and decompression sickness (DCS). Propranolol was shown to reduce CO2 production in an experimental DISSUB model in humans but its effects on DCS in a DISSUB rescue scenario are unknown. A 100% oxygen prebreathe (OPB) reduces DCS incidence and severity and is incorporated into some DISSUB rescue protocols. We used a swine model of DISSUB rescue to study the effect of propranolol on DCS incidence and mortality with and without an OPB. In Experiment 1, male Yorkshire Swine (70 kg) were pressurized to 2.8 ATA for 22 h. Propranolol 1.0 mg · kg-1 (IV) was administered at 21.25 h. At 22 h, the animal was rapidly decompressed and observed for DCS type, onset time, and mortality. Experimental animals (N = 21; 69 ± 4.1 kg), PROP1.0, were compared to PROP1.0-OPB45 (N = 8; 69 ± 2.8 kg) with the same dive profile, except for a 45 min OPB prior to decompression. In Experiment 2, the same methodology was used with the following changes: swine pressurized to 2.8 ATA for 28 h; experimental group (N = 25; 67 ± 3.3 kg), PROP0.5 bis, propranolol 0.5 mg · kg-1 bis (twice) (IV) was administered at 22 h and 26 h. Control animals (N = 25; 67 ± 3.9 kg) received normal saline. OPB reduced mortality in PROP1.0-OBP45 compared to PROP1.0 (0% vs. 71%). PROP0.5 bis had increased mortality compared to CONTROL (60-% vs. 4%). Administration of beta blockers prior to saturation decompression appears to increase DCS and worsen mortality in a swine model; however, their effects in bounce diving remain unknown.Forbes AS, Regis DP, HallAA, Mahon RT, Cronin WA. Propranolol effects on decompression sickness in a simulated DISSUB rescue in swine. Aerosp Med Hum Perform. 2017; 88(4):385-391.

ORACLE Stroke Study: Opinion Regarding Acceptable Outcome Following Decompressive Hemicraniectomy for Ischemic Stroke.

PubMed

Honeybul, Stephen; Ho, Kwok M; Blacker, David W

2016-08-01

There continues to be considerable interest in the use of decompressive hemicraniectomy in the management of malignant cerebral artery infarction; however, concerns remain about long-term outcome. To assess opinion on consent and acceptable outcome among a wide range of healthcare workers. Seven hundred seventy-three healthcare workers at the 2 major public neurosurgical centers in Western Australia participated. Participants were asked to record their opinion on consent and acceptable outcome based on the modified Rankin Score (mRS). The evidence for clinical efficacy of the procedure was presented, and participants were then asked to reconsider their initial responses. Of the 773 participants included in the study, 407 (52.7%) initially felt that they would provide consent for a decompressive craniectomy as a lifesaving procedure, but only a minority of them considered an mRS score of 4 or 5 an acceptable outcome (for mRS score ≤4, n = 67, 8.7%; for mRS score = 4, n = 57, 7.4%). After the introduction of the concept of the disability paradox and the evidence for the clinical efficacy of decompressive craniectomy, more participants were unwilling to accept decompressive craniectomy (18.1% vs 37.8%), but at the same time, more were willing to accept an mRS score ≤4 as an acceptable outcome (for mRS score ≤4, n = 92, 11.9%; for mRS score = 4, n = 79, 10.2%). Most participants felt survival with dependency to be unacceptable. However, many would be willing to provide consent for surgery in the hopes that they may survive with some degree of independence. DESTINY, Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral ArterymRS, modified Rankin Scale.

The effects of venting and decompression on Yellow Tang (Zebrasoma flavescens) in the marine ornamental aquarium fish trade

PubMed Central

Tissot, Brian N.; Heidel, Jerry R.; Miller-Morgan, Tim

2015-01-01

Each year, over 45 countries export 30 million fish from coral reefs as part of the global marine ornamental aquarium trade. This catch volume is partly influenced by collection methods that cause mortality. Barotrauma in fish resulting from forced ascent from depth can contribute to post-collection mortality. However, implementing decompression stops during ascent can prevent barotrauma. Conversely, venting (puncturing the swim bladder to release expanded internal gas) following ascent can mitigate some signs of barotrauma like positive buoyancy. Here, we evaluate how decompression and venting affect stress and mortality in the Yellow Tang (Zebrasoma flavescens). We examined the effects of three ascent treatments, each with decompression stops of varying frequency and duration, coupled with or without venting, on sublethal effects and mortality using histology and serum cortisol measurements. In fish subjected to ascent without decompression stops or venting, a mean post-collection mortality of 6.2% occurred within 24 h of capture. Common collection methods in the fishery, ascent without decompression stops coupled with venting, or one long decompression stop coupled with venting, resulted in no mortality. Histopathologic examination of heart, liver, head kidney, and swim bladder tissues in fish 0d and 21d post-collection revealed no significant barotrauma- or venting-related lesions in any treatment group. Ascent without decompression stops resulted in significantly higher serum cortisol than ascent with many stops, while venting alone did not affect cortisol. Future work should examine links in the supply chain following collection to determine if further handling and transport stressors affect survivorship and sublethal effects. PMID:25737809

Effect of Subspine Decompression on Rectus Femoris Integrity and Iliopsoas Excursion: A Cadaveric Study.

PubMed

El-Shaar, Rami; Stanton, Michael; Biehl, Scott; Giordano, Brian

2015-10-01

To determine the relative influence of anteroinferior iliac spine (AIIS) or subspine decompression on proximal rectus femoris integrity and iliopsoas excursion throughout a physiological range of motion. Nineteen cadaveric hips from 10 specimens were dissected to retain the origin of the rectus femoris direct and indirect heads. The anatomic footprints of the origins were measured with calipers. Serial 5-mm resections of the AIIS were made to determine the extent of proximal tendon disruption that corresponded to each resection. Iliopsoas tendon tracking was also assessed after sequential AIIS decompression by measuring the excursion of the medial border of the iliopsoas tendon as it traveled from its native resting position to the point where it first encountered bony impingement at the AIIS. The mean proximal-distal footprint of the rectus femoris direct head was 17.95 ± 2.99 mm. The mean medial-lateral distance was 11.84 ± 2.34 mm. There was a consistent bare area along the inferior aspect of the AIIS that averaged 4.84 ± 1.42 mm. The average percentage of remaining footprint after each 5-mm resection (5 to 25 mm) was 96%, 65%, 35%, 14%, and 11%, respectively, with statistical significance noted after resections larger than 5 mm (P < .001). The native excursion distance of the iliopsoas tendon was 14.05 mm. With each 5-mm resection, the percentage of excursion before impingement on the AIIS increased by 18%, 45%, 72%, 95%, and 100%, respectively, which was statistically significance after all resections (P < .001). Our study maps the anatomic footprint of the direct head of the rectus femoris tendon and confirms a previously identified bare area along the inferior aspect of the AIIS. Female cadaveric hips had a significantly smaller rectus footprint than male cadavers in our study (P < .001). Subspine decompression greater than 10 mm significantly compromises the rectus femoris origin and should be avoided when performing arthroscopic AIIS decompression. In

Decompressive craniectomy and cranioplasty: experience and outcomes in deployed UK military personnel.

PubMed

Roberts, S A G; Toman, E; Belli, A; Midwinter, M J

2016-10-01

In recent conflicts, many UK personnel sustained head injuries requiring damage-control surgery and aeromedical transfer to the UK. This study aims to examine indications, complications and outcomes of UK military casualties undergoing craniectomy and cranioplasty from conflicts in Afghanistan and Iraq. The UK military Joint Theatre Trauma Registry (JTTR) was searched for all UK survivors in Afghanistan and Iraq between 2004 and 2014 requiring craniectomy and cranioplasty resulting from trauma. Fourteen decompressive craniectomies and cranioplasties were performed with blast and gunshot wounds equally responsible for head injury. Ten survivors (71%) had an Injury Severity Score (ISS) of 75, normally designated as 'unsurvivable'. Most were operated on the day of injury. Seventy-one percent received a reverse question mark incision and 7% received a bicoronal incision. Seventy-nine percent had bone flaps discarded. Overall infection rate was 43%. Acinetobacter spp was the causative organism in 50% of cases. Median Glasgow Outcome Scale (GOS) at final follow-up was 4. All casualties had a GOS score greater than 3. Timely neurosurgical intervention is imperative for military personnel given high survival rates in those sustaining what are designated 'un-survivable' injuries. Early decompression facilitates safe aeromedical evacuation of casualties. Excellent outcomes validate the UK military trauma system and the stepwise performance gains throughout recent conflicts however trauma registers most evolving to have specific relevance to military casualties. In high-energy trauma with contamination and soft-tissue destruction, surgery should be conducted with regard for future soft tissue reconstruction. Bone flaps should be discarded and cranioplasty performed according to local preference. Facilities receiving military casualties should have specialist microbiological input mindful of the difficulties treating unusual microbes.

[Comparison of posterior fossa decompression with and without duraplasty for surgical management for adult Chiari malformation type Ⅰ].

PubMed

Li, H Y; Li, Y M; Chen, H; Li, Y; Shi, X W

2017-07-04

Objective: To evaluate and compare the efficacy between posterior fossa decompression without duraplasty (PFD) and posterior fossa decompression with duraplasty (PFDD) in the surgical management for adult Chiari Ⅰ malformation. Methods: Fifty-seven patients suffered from Chiari malformation type Ⅰ were treated in Department of Neurosurgery, Henan Provincial People's Hospital from August 2008 to October 2013. Twenty-three patients received posterior fossa decompression without duraplasty and the other 34 patients received posterior fossa decompression with duraplasty. The clinical results were retrospectively analyzed to compare the efficacy of two different surgical approaches. Results: There was no death or severe neurological dysfunction case in 57 patients of the two groups. Patients undergoing PFD had shorter length of hospital stay[(13.7±3.5) d vs (16.2±4.1) d, P <0.05]and surgical time[(98.7±22.1) min vs (132.3±39.6)min, P <0.05]. Cerebrospinal fluid-related complications and intracranial infection were more common in patients undergoing PFDD[(0/23, 0) vs (8/34, 23.5%), P <0.05]. Clinical improvement was comparable in two groups[(15/23, 65.2%) vs (26/34, 76.5%), P >0.05]at the one-year follow-up. The rate of syrinx regression in patients with Syringomyelia was higher in patients undergoing PFDD[(3/12, 25%) vs (17/22, 77.3%), P <0.05]. Conclusion: For adult patients with Chiari malformation type Ⅰ, PFD has the advantages of simple manipulation, short length of hospital stay and low incidence of cerebrospinal fluid-related complications and intracranial infection, compared with PFDD. It is comparable to PFDD in clinical improvement, but the effect of PFD is not as good as that of PFDD in the aspect of syrinx regression.

Validation of the CRASH model in the prediction of 18-month mortality and unfavorable outcome in severe traumatic brain injury requiring decompressive craniectomy.

PubMed

Honeybul, Stephen; Ho, Kwok M; Lind, Christopher R P; Gillett, Grant R

2014-05-01

The goal in this study was to assess the validity of the corticosteroid randomization after significant head injury (CRASH) collaborators prediction model in predicting mortality and unfavorable outcome at 18 months in patients with severe traumatic brain injury (TBI) requiring decompressive craniectomy. In addition, the authors aimed to assess whether this model was well calibrated in predicting outcome across a wide spectrum of severity of TBI requiring decompressive craniectomy. This prospective observational cohort study included all patients who underwent a decompressive craniectomy following severe TBI at the two major trauma hospitals in Western Australia between 2004 and 2012 and for whom 18-month follow-up data were available. Clinical and radiological data on initial presentation were entered into the Web-based model and the predicted outcome was compared with the observed outcome. In validating the CRASH model, the authors used area under the receiver operating characteristic curve to assess the ability of the CRASH model to differentiate between favorable and unfavorable outcomes. The ability of the CRASH 6-month unfavorable prediction model to differentiate between unfavorable and favorable outcomes at 18 months after decompressive craniectomy was good (area under the receiver operating characteristic curve 0.85, 95% CI 0.80-0.90). However, the model's calibration was not perfect. The slope and the intercept of the calibration curve were 1.66 (SE 0.21) and -1.11 (SE 0.14), respectively, suggesting that the predicted risks of unfavorable outcomes were not sufficiently extreme or different across different risk strata and were systematically too high (or overly pessimistic), respectively. The CRASH collaborators prediction model can be used as a surrogate index of injury severity to stratify patients according to injury severity. However, clinical decisions should not be based solely on the predicted risks derived from the model, because the number of

Economic evaluation of decompressive craniectomy versus barbiturate coma for refractory intracranial hypertension following traumatic brain injury.

PubMed

Alali, Aziz S; Naimark, David M J; Wilson, Jefferson R; Fowler, Robert A; Scales, Damon C; Golan, Eyal; Mainprize, Todd G; Ray, Joel G; Nathens, Avery B

2014-10-01

Decompressive craniectomy and barbiturate coma are often used as second-tier strategies when intracranial hypertension following severe traumatic brain injury is refractory to first-line treatments. Uncertainty surrounds the decision to choose either treatment option. We investigated which strategy is more economically attractive in this context. We performed a cost-utility analysis. A Markov Monte Carlo microsimulation model with a life-long time horizon was created to compare quality-adjusted survival and cost of the two treatment strategies, from the perspective of healthcare payer. Model parameters were estimated from the literature. Two-dimensional simulation was used to incorporate parameter uncertainty into the model. Value of information analysis was conducted to identify major drivers of decision uncertainty and focus future research. Trauma centers in the United States. Base case was a population of patients (mean age = 25 yr) who developed refractory intracranial hypertension following traumatic brain injury. We compared two treatment strategies: decompressive craniectomy and barbiturate coma. Decompressive craniectomy was associated with an average gain of 1.5 quality-adjusted life years relative to barbiturate coma, with an incremental cost-effectiveness ratio of $9,565/quality-adjusted life year gained. Decompressive craniectomy resulted in a greater quality-adjusted life expectancy 86% of the time and was more cost-effective than barbiturate coma in 78% of cases if our willingness-to-pay threshold is $50,000/quality-adjusted life year and 82% of cases at a threshold of $100,000/quality-adjusted life year. At older age, decompressive craniectomy continued to increase survival but at higher cost (incremental cost-effectiveness ratio = $197,906/quality-adjusted life year at mean age = 85 yr). Based on available evidence, decompressive craniectomy for the treatment of refractory intracranial hypertension following traumatic brain injury provides better

[Surgical outcome of external decompression associated with anterior and medial temporal lobectomy for massive hemispheric infarction due to internal carotid artery occlusion].

PubMed

Yamazaki, Takaaki; Kamiyama, Kenji; Osato, Toshiaki; Sasaki, Takehiko; Nakagawara, Jyoji; Nakamura, Hirohiko

2010-01-01

Acute occlusion of the internal carotid artery (ICA) can lead the massive cerebral hemispheric infarction and cause massive cerebral edema and may result in tentorial herniation and death. The mortality rate is estimated at 80% with maximum conservative medical treatment. We have performed external decompression associated with anterior and medial temporal lobectomy (AMTL) as internal decompression for lifesaving. This study evaluated our surgical results and gives an analysis of the prognostic factors. Twenty one consecutive patients with massive cerebral infarction caused by internal carotid artery occlusion who underwent external decompression associated with AMTL for lifesaving between June 2000 and December 2005 were included in this retrospective analysis. Survivors were divided into two functional groups at three months after surgery: good (Barthel index; BI> or =50) and poor (B1<50). The characteristics of the two groups were compared using statistical analysis. The patients consisted of 11 males and 10 females aged from 28 to 81 years with a mean age of 65.0+/-11.6 years. Eight patients had an infarction restricted to the middle cerebral artery (MCA) territory, others had additional anterior cerebral artery (ACA) or posterior cerebral artery (PCA) territory infarctions. The mean time between stroke onset and operation was 43.5+/-30 hours and ranged from 7 to 148 hours. Two patients died, so the mortality was 9.5%. Elderly patients (> or =60 years) (P=0.038), high preoperative Japan coma scale (> or =3 digit) (P=0.013), low preoperative Glasgow coma scale (GCS<8) (P=0.044), and multiple arterial territory (MCA+ACA or PCA) infarction (P=0.045) were significantly associated with poor functional outcome. External decompression associated with AMTL can immediately relieve peduncle compression and could be effective in preserving life as effectively as "early" external decompression.

Decompression Device Using a Stainless Steel Tube and Wire for Treatment of Odontogenic Cystic Lesions: A Technical Report.

PubMed

Jung, Eun-Joo; Baek, Jin-A; Leem, Dae-Ho

2014-11-01

Decompression is considered an effective treatment for odontogenic cystic lesions in the jaw. A variety of decompression devices are successfully used for the treatment of keratocystic odontogenic tumors, radicular cysts, dentigerous cysts, and ameloblastoma. The purpose of these devices is to keep an opening between the cystic lesion and the oral environment during treatment. The aim of this report is to describe an effective decompression tube using a stainless steel tube and wire for treatment of jaw cystic lesions.

Interspinous Process Decompression: Expanding Treatment Options for Lumbar Spinal Stenosis

PubMed Central

Nunley, Pierce D.; Shamie, A. Nick; Blumenthal, Scott L.; Orndorff, Douglas; Geisler, Fred H.

2016-01-01

Interspinous process decompression is a minimally invasive implantation procedure employing a stand-alone interspinous spacer that functions as an extension blocker to prevent compression of neural elements without direct surgical removal of tissue adjacent to the nerves. The Superion® spacer is the only FDA approved stand-alone device available in the US. It is also the only spacer approved by the CMS to be implanted in an ambulatory surgery center. We computed the within-group effect sizes from the Superion IDE trial and compared them to results extrapolated from two randomized trials of decompressive laminectomy. For the ODI, effect sizes were all very large (>1.0) for Superion and laminectomy at 2, 3, and 4 years. For ZCQ, the 2-year Superion symptom severity (1.26) and physical function (1.29) domains were very large; laminectomy effect sizes were very large (1.07) for symptom severity and large for physical function (0.80). Current projections indicate a marked increase in the number of patients with spinal stenosis. Consequently, there remains a keen interest in minimally invasive treatment options that delay or obviate the need for invasive surgical procedures, such as decompressive laminectomy or fusion. Stand-alone interspinous spacers may fill a currently unmet treatment gap in the continuum of care and help to reduce the burden of this chronic degenerative condition on the health care system. PMID:27819001

Interspinous Process Decompression: Expanding Treatment Options for Lumbar Spinal Stenosis.

PubMed

Nunley, Pierce D; Shamie, A Nick; Blumenthal, Scott L; Orndorff, Douglas; Block, Jon E; Geisler, Fred H

2016-01-01

Interspinous process decompression is a minimally invasive implantation procedure employing a stand-alone interspinous spacer that functions as an extension blocker to prevent compression of neural elements without direct surgical removal of tissue adjacent to the nerves. The Superion® spacer is the only FDA approved stand-alone device available in the US. It is also the only spacer approved by the CMS to be implanted in an ambulatory surgery center. We computed the within-group effect sizes from the Superion IDE trial and compared them to results extrapolated from two randomized trials of decompressive laminectomy. For the ODI, effect sizes were all very large (>1.0) for Superion and laminectomy at 2, 3, and 4 years. For ZCQ, the 2-year Superion symptom severity (1.26) and physical function (1.29) domains were very large ; laminectomy effect sizes were very large (1.07) for symptom severity and large for physical function (0.80). Current projections indicate a marked increase in the number of patients with spinal stenosis. Consequently, there remains a keen interest in minimally invasive treatment options that delay or obviate the need for invasive surgical procedures, such as decompressive laminectomy or fusion. Stand-alone interspinous spacers may fill a currently unmet treatment gap in the continuum of care and help to reduce the burden of this chronic degenerative condition on the health care system.

Use of ultrasound in altitude decompression modeling

NASA Technical Reports Server (NTRS)

Olson, Robert M.; Pilmanis, Andrew A.

1993-01-01

A model that predicts the probability of developing decompression sickness (DCS) with various denitrogenation schedules is being developed by the Armstrong Laboratory, using human data from previous exposures. It was noted that refinements are needed to improve the accuracy and scope of the model. A commercially developed ultrasonic echo imaging system is being used in this model development. Using this technique, bubbles images from a subject at altitude can be seen in the gall bladder, hepatic veins, vena cava, and chambers of the heart. As judged by their motion and appearance in the vena cava, venous bubbles near the heart range in size from 30 to 300 M. The larger bubbles skim along the top, whereas the smaller ones appear as faint images near the bottom of the vessel. Images from growing bubbles in a model altitude chamber indicate that they grow rapidly, going from 20 to 100 M in 3 sec near 30,000 ft altitude. Information such as this is valuable in verifying those aspects of the DCS model dealing with bubble size, their growth rate, and their site of origin.

Influence of Lumbar Lordosis on the Outcome of Decompression Surgery for Lumbar Canal Stenosis.

PubMed

Chang, Han Soo

2018-01-01

Although sagittal spinal balance plays an important role in spinal deformity surgery, its role in decompression surgery for lumbar canal stenosis is not well understood. To investigate the hypothesis that sagittal spinal balance also plays a role in decompression surgery for lumbar canal stenosis, a prospective cohort study analyzing the correlation between preoperative lumbar lordosis and outcome was performed. A cohort of 85 consecutive patients who underwent decompression for lumbar canal stenosis during the period 2007-2011 was analyzed. Standing lumbar x-rays and 36-item short form health survey questionnaires were obtained before and up to 2 years after surgery. Correlations between lumbar lordosis and 2 parameters of the 36-item short form health survey (average physical score and bodily pain score) were statistically analyzed using linear mixed effects models. There was a significant correlation between preoperative lumbar lordosis and the 2 outcome parameters at postoperative, 6-month, 1-year, and 2-year time points. A 10° increase of lumbar lordosis was associated with a 5-point improvement in average physical scores. This correlation was not present in preoperative scores. This study showed that preoperative lumbar lordosis significantly influences the outcome of decompression surgery on lumbar canal stenosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Rapid versus gradual bladder decompression in acute urinary retention

PubMed Central

Etafy, Mohamed H.; Saleh, Fatma H.; Ortiz-Vanderdys, Cervando; Hamada, Alaa; Refaat, Alaa M.; Aal, Mohamed Abdel; Deif, Hazem; Gawish, Maher; Abdellatif, Ashraf H.; Gadalla, Khaled

2017-01-01

Objective: To demonstrate a benefit in diminished adverse events such as hypotension and hematuria with gradual drainage of the bladder when compared to rapid decompression in patients with acute urinary retention (AUR) due to benign prostatic hyperplasia in a case–control study. Methods: Sixty-two patients matched our selection criteria presenting with AUR. They were divided into two groups – the first was managed by rapid drainage of the bladder, the second was managed by gradual drainage through a urethral catheter (The first 100 mL immediately evacuated, then the rest evacuated gradually over 2 h). Results: The mean age was 64.4 and 63.2 years in the first and second group, respectively. Diagnosed cause was benign hyperplasia of the prostate. Hematuria occurred in two patients in the first group and none in the second group. The two cases of hematuria were mild and treated conservatively. After the relief of the obstruction, the mean blood pressure was noticed to decrease by 15 mmHg and 10 mmHg in the first and second group, respectively, however, no one developed significant hypotension. Pain relief was achieved after complete drainage in the first group and after the evacuation of 100 mL in the second group. Conclusions: We conclude that there is no significant difference between rapid and gradual decompression of the bladder in patients with AUR. Hematuria and hypotension may occur after rapid decompression of the obstructed urinary bladder, but these complications are rarely clinically significant. PMID:29118535

Decompressive craniectomy in severe traumatic brain injury: prognostic factors and complications

PubMed Central

Grille, Pedro; Tommasino, Nicolas

2015-01-01

Objective To analyze the clinical characteristics, complications and factors associated with the prognosis of severe traumatic brain injury among patients who undergo a decompressive craniectomy. Methods Retrospective study of patients seen in an intensive care unit with severe traumatic brain injury in whom a decompressive craniectomy was performed between the years 2003 and 2012. Patients were followed until their discharge from the intensive care unit. Their clinical-tomographic characteristics, complications, and factors associated with prognosis (univariate and multivariate analysis) were analyzed. Results A total of 64 patients were studied. Primary and lateral decompressive craniectomies were performed for the majority of patients. A high incidence of complications was found (78% neurological and 52% nonneurological). A total of 42 patients (66%) presented poor outcomes, and 22 (34%) had good neurological outcomes. Of the patients who survived, 61% had good neurological outcomes. In the univariate analysis, the factors significantly associated with poor neurological outcome were postdecompressive craniectomy intracranial hypertension, greater severity and worse neurological state at admission. In the multivariate analysis, only postcraniectomy intracranial hypertension was significantly associated with a poor outcome. Conclusion This study involved a very severe and difficult to manage group of patients with high morbimortality. Intracranial hypertension was a main factor of poor outcome in this population. PMID:26340150

Alternative technique in atypical spinal decompression: the use of the ultrasonic scalpel in paediatric achondroplasia

PubMed Central

Woodacre, Timothy; Sewell, Matthew; Clarke, Andrew J; Hutton, Mike

2016-01-01

Spinal stenosis can be a very disabling condition. Surgical decompression carries a risk of dural tear and neural injury, which is increased in patients with severe stenosis or an atypical anatomy. We present an unusual case of symptomatic stenosis secondary to achondroplasia presenting in a paediatric patient, and highlight a new surgical technique used to minimise the risk of dural and neural injury during decompression. PMID:27288205

Current concepts in repair of extremity venous injury.

PubMed

Williams, Timothy K; Clouse, W Darrin

2016-04-01

Extremity venous injury management remains controversial. The purpose of this communication is to offer perspective as well as experiential and technical insight into extremity venous injury repair. Available literature is reviewed and discussed. Historical context is provided. Indication, the decision process for repair, including technical conduct, is delineated. In particular, the authors' experiences in both civilian and wartime injury are used for perspective. Extremity venous injury repair was championed within data from the Vietnam Vascular Registry. However, patterns of extremity venous injury differ between combat and civilian settings. Since Vietnam, civilian descriptive series opine the benefits and potential complications associated with both venous injury repair and ligation. These surround extremity edema, chronic venous insufficiency, thromboembolism, and limb loss. Whereas no clear superiority in either approach has been identified to date, there appears to be no increased risk of pulmonary embolism or chronic venous changes with repair. Newer data from the wars in Iraq and Afghanistan and meta-analysis have reinforced this and also have suggested limb salvage benefit for extremity venous repair in combined arterial and venous injuries in modern settings. The patient's physiologic state and associated injury drive five triage categories suggesting vein injury management. Vein repair thrombosis occurs in a significant proportion, yet many recanalize and possibly have a positive impact on limb venous return. Further, early decompression favors reduced blood loss, acute edema, and inflammation, supporting collateral development. Large soft tissue injury minimizing collateral capacity increases the importance of repair. Constructs of repair are varied with modest differences in patency. Venous shunting is feasible, but specific roles remain nebulous. An aggressive posture toward extremity venous injury repair seems justified today because of the likely

Orbital Electron Capture Rates in Extreme Astrophysical Environments

NASA Astrophysics Data System (ADS)

Martin, Matthew; McDonald, William; Leach, Kyle

2017-09-01

In an attempt to better understand EC decay rates in hot environments, we have developed a program to examine and parse all evaluated atomic and nuclear data. Taking into account the effects of ionization on accessible decay states and electron capture probabilities, half lives across the nuclear chart can be investigated without the need for theoretical estimates. Part of the ongoing project will include isolating stable isotopes that become unstable due to ionization and estimating their stability in these new environments. In addition, we hope to account for a thermal population of excited states to better simulate these environments. This should aide in the complete understanding of nuclear processes in these extreme astrophysical environments. This work is supported in part by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics.

Development of Korean Academy of Medical Sciences Guideline for rating physical disability of upper extremity.

PubMed

Park, Jung Ho; Kim, Hee-Chun; Lee, Jae Hoon; Kim, Jin Soo; Roh, Si Young; Yi, Cheol Ho; Kang, Yoon Kyoo; Kwon, Bum Sun

2009-05-01

While the lower extremities support the weight and move the body, the upper extremities are essential for the activities of daily living, which require many detailed movements. Therefore, a disability of the upper extremity function should include a limitation of all motions of the joints and sensory loss, which affects the activities. In this study, disabilities of the upper extremities were evaluated according to the following conditions: 1) amputation, 2) joint contracture, 3) diseases of upper extremity, 4) weakness, 5) sensory loss of the finger tips, and 6) vascular and lymphatic diseases. The order of 1) to 6) is the order of major disability and there is no need to evaluate a lower order disability when a higher order one exists in the same joint or a part of the upper extremity. However, some disabilities can be either added or substituted when there are special contributions from multiple disabilities. An upper extremity disability should be evaluated after the completion of treatment and full adaptation when further functional changes are not expected. The dominance of the right or left hand before the disability should not be considered when there is a higher rate of disability.

Strain on intervertebral discs after anterior cervical decompression and fusion.

PubMed

Matsunaga, S; Kabayama, S; Yamamoto, T; Yone, K; Sakou, T; Nakanishi, K

1999-04-01

An analysis of the change in strain distribution of intervertebral discs present after anterior cervical decompression and fusion by an original method. The analytical results were compared to occurrence of herniation of the intervertebral disc on magnetic resonance imaging. To elucidate the influence of anterior cervical decompression and fusion on the unfused segments of the spine. There is no consensus regarding the exact significance of the biomechanical change in the unfused segment present after surgery. Ninety-six patients subjected to anterior cervical decompression and fusion for herniation of intervertebral discs were examined. Shear strain and longitudinal strain of intervertebral discs were analyzed on pre- and postoperative lateral dynamic routine radiography of the cervical spine. Thirty of the 96 patients were examined by magnetic resonance imaging before and after surgery, and the relation between alteration in strains and postsurgical occurrence of disc herniation was examined. In the cases of double- or triple-level fusion, shear strain of adjacent segments had increased 20% on average 1 year after surgery. Thirteen intervertebral discs that had an abnormally high degree of strain showed an increase in longitudinal strain after surgery. Eleven (85%) of the 13 discs that showed an abnormal increase in longitudinal strain had herniation in the same intervertebral discs with compression of the spinal cord during the follow-up period. Relief of symptoms was significantly poor in the patients with recent herniation. Close attention should be paid to long-term biomechanical changes in the unfused segment.

MRI-guidance in percutaneous core decompression of osteonecrosis of the femoral head.

PubMed

Kerimaa, Pekka; Väänänen, Matti; Ojala, Risto; Hyvönen, Pekka; Lehenkari, Petri; Tervonen, Osmo; Blanco Sequeiros, Roberto

2016-04-01

The purpose of this study was to evaluate the usefulness of MRI-guidance for core decompression of avascular necrosis of the femoral head. Twelve MRI-guided core decompressions were performed on patients with different stages of avascular necrosis of the femoral head. The patients were asked to evaluate their pain and their ability to function before and after the procedure and imaging findings were reviewed respectively. Technical success in reaching the target was 100 % without complications. Mean duration of the procedure itself was 54 min. All patients with ARCO stage 1 osteonecrosis experienced clinical benefit and pathological MRI findings were seen to diminish. Patients with more advanced disease gained less, if any, benefit and total hip arthroplasty was eventually performed on four patients. MRI-guidance seems technically feasible, accurate and safe for core decompression of avascular necrosis of the femoral head. Patients with early stage osteonecrosis may benefit from the procedure. • MRI is a useful guidance method for minimally invasive musculoskeletal interventions. • Bone drilling seems beneficial at early stages of avascular necrosis. • MRI-guidance is safe and accurate for bone drilling.

Current practice of thoracic outlet decompression surgery in the United States.

PubMed

Rinehardt, Elena K; Scarborough, John E; Bennett, Kyla M

2017-09-01

Thoracic outlet syndrome (TOS) and its management are relatively controversial topics. Most of the literature reporting the outcomes of surgical decompression for TOS derives from single-center experiences. The objective of our study was to describe the current state of TOS surgery among hospitals that participate in the American College of Surgeons National Surgical Quality Improvement Program database. Our study sample consisted of patients from the 2005 to 2014 American College of Surgeons National Surgical Quality Improvement Program database who underwent first or cervical rib resection as their index procedure and whose constellation of diagnosis and procedure codes identified them as having neurogenic, arterial, or venous TOS. Patient and procedure characteristics were determined, as were the 30-day incidence of specific complications including nerve injury. Multimodel inference was used for multivariable analysis of the composite outcome of readmission or reoperation ≤30 days. We identified 1431 patients undergoing operation for TOS: 83% for neurogenic TOS, 3% for arterial TOS, and 12% for venous TOS. Vascular surgeons performed 90% of procedures. Only four patients (0.3%) demonstrated evidence of nerve injury. The rate of bleeding complication requiring transfusion was also quite low, at 1.4%. The 30-day incidence of readmission or reoperation, or both, in our study cohort was 8.6%. The risk of this outcome was increased in patients with a higher American Society of Anesthesiologists Physical Status Classification, those whose procedure was for non-neurogenic symptoms, and those whose procedure took longer to complete. The findings of our study will provide surgeons who advocate for the surgical management of TOS with reassurance that such intervention is associated with an extremely low risk of disability resulting from iatrogenic nerve injury and major bleeding events. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All

Image compression/decompression based on mathematical transform, reduction/expansion, and image sharpening

DOEpatents

Fu, Chi-Yung; Petrich, Loren I.

1997-01-01

An image represented in a first image array of pixels is first decimated in two dimensions before being compressed by a predefined compression algorithm such as JPEG. Another possible predefined compression algorithm can involve a wavelet technique. The compressed, reduced image is then transmitted over the limited bandwidth transmission medium, and the transmitted image is decompressed using an algorithm which is an inverse of the predefined compression algorithm (such as reverse JPEG). The decompressed, reduced image is then interpolated back to its original array size. Edges (contours) in the image are then sharpened to enhance the perceptual quality of the reconstructed image. Specific sharpening techniques are described.

Image compression/decompression based on mathematical transform, reduction/expansion, and image sharpening

DOEpatents

Fu, C.Y.; Petrich, L.I.

1997-12-30

An image represented in a first image array of pixels is first decimated in two dimensions before being compressed by a predefined compression algorithm such as JPEG. Another possible predefined compression algorithm can involve a wavelet technique. The compressed, reduced image is then transmitted over the limited bandwidth transmission medium, and the transmitted image is decompressed using an algorithm which is an inverse of the predefined compression algorithm (such as reverse JPEG). The decompressed, reduced image is then interpolated back to its original array size. Edges (contours) in the image are then sharpened to enhance the perceptual quality of the reconstructed image. Specific sharpening techniques are described. 22 figs.

Effect of metabolic gases and water vapor, perfluorocarbon emulsions, and nitric oxide on tissue bubbles during decompression sickness.

PubMed

Randsøe, Thomas

2016-05-01

In aviation and diving, fast decrease in ambient pressure, such as during accidental loss of cabin pressure or when a diver decompresses too fast to sea level, may cause nitrogen (N2) bubble formation in blood and tissue resulting in decompression sickness (DCS). Conventional treatment of DCS is oxygen (O2) breathing combined with recompression.  However, bubble kinetic models suggest, that metabolic gases, i.e. O2 and carbon dioxide (CO2), and water vapor contribute significantly to DCS bubble volume and growth at hypobaric altitude exposures. Further, perfluorocarbon emulsions (PFC) and nitric oxide (NO) donors have, on an experimental basis, demonstrated therapeutic properties both as treatment and prophylactic intervention against DCS. The effect was ascribed to solubility of respiratory gases in PFC, plausible NO elicited nuclei demise and/or N2 washout through enhanced blood flow rate. Accordingly, by means of monitoring injected bubbles in exposed adipose tissue or measurements of spinal evoked potentials (SEPs) in anaesthetized rats, the aim of this study was to: 1) evaluate the contribution of metabolic gases and water vapor to bubble volume at different barometrical altitude exposures, 2) clarify the O2 contribution and N2 solubility from bubbles during administration of PFC at normo- and hypobaric conditions and, 3) test the effect of different NO donors on SEPs during DCS upon a hyperbaric air dive and, to study the influence of  NO on tissue bubbles at high altitude exposures. The results support the bubble kinetic models and indicate that metabolic gases and water vapor contribute significantly to bubble volume at 25 kPa (~10,376 m above sea level) and constitute a threshold for bubble stabilization or decay at the interval of 47-36 kPa (~6,036 and ~7,920 m above sea level). The effect of the metabolic gases and water vapor seemed to compromise the therapeutic properties of both PFC and NO at altitude, while PFC significantly increased bubble

Compositional Discrimination of Decompression and Decomposition Gas Bubbles in Bycaught Seals and Dolphins

PubMed Central

Bernaldo de Quirós, Yara; Seewald, Jeffrey S.; Sylva, Sean P.; Greer, Bill; Niemeyer, Misty; Bogomolni, Andrea L.; Moore, Michael J.

2013-01-01

Gas bubbles in marine mammals entangled and drowned in gillnets have been previously described by computed tomography, gross examination and histopathology. The absence of bacteria or autolytic changes in the tissues of those animals suggested that the gas was produced peri- or post-mortem by a fast decompression, probably by quickly hauling animals entangled in the net at depth to the surface. Gas composition analysis and gas scoring are two new diagnostic tools available to distinguish gas embolisms from putrefaction gases. With this goal, these methods have been successfully applied to pathological studies of marine mammals. In this study, we characterized the flux and composition of the gas bubbles from bycaught marine mammals in anchored sink gillnets and bottom otter trawls. We compared these data with marine mammals stranded on Cape Cod, MA, USA. Fresh animals or with moderate decomposition (decomposition scores of 2 and 3) were prioritized. Results showed that bycaught animals presented with significantly higher gas scores than stranded animals. Gas composition analyses indicate that gas was formed by decompression, confirming the decompression hypothesis. PMID:24367623

Endoscopic foraminal decompression for failed back surgery syndrome under local anesthesia.

PubMed

Yeung, Anthony; Gore, Satishchandra

2014-01-01

The most common causes of failed back surgery are residual or recurrent herniation, foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. Residual back ache may also be from facetal causes or denervation and scarring of the paraspinal muscles.(1-6) The original surgeon may advise his patient that nothing more can be done on the basis of his opinion that the nerve was visually decompressed by the original surgery, supported by improved post-op imaging and follow-up studies such as EMG and conduction velocity studies. Post-op imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of Failed back surgery by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain, therefore necessitating fusion. The authors, having limited their practice to endoscopic MIS surgery over the last 15-20 years, report on their experience gained during that period to relieve pain by endoscopically visualizing and treating unrecognized causative patho-anatomy in FBSS.(7.) Thirty consecutive patients with FBSS presenting with back and leg pain that had supporting imaging diagnosis of lateral stenosis and /or residual / recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections (Figure 1), were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open translaminar surgical treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen for foraminal stenosis, or foraminoplasty to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla, also known as the "hidden zone" of Macnab

Endoscopic Foraminal Decompression for Failed Back Surgery Syndrome under local Anesthesia

PubMed Central

Gore, Satishchandra

2014-01-01

Background The most common causes of failed back surgery are residual or recurrent herniation, foraminal fibrosis and foraminal stenosis that is ignored, untreated, or undertreated. Residual back ache may also be from facetal causes or denervation and scarring of the paraspinal muscles.1–6 The original surgeon may advise his patient that nothing more can be done on the basis of his opinion that the nerve was visually decompressed by the original surgery, supported by improved post-op imaging and follow-up studies such as EMG and conduction velocity studies. Post-op imaging or electrophysiological assessment may be inadequate to explain all the reasons for residual or recurrent symptoms. Treatment of Failed back surgery by repeat traditional open revision surgery usually incorporates more extensive decompression causing increased instability and back pain, therefore necessitating fusion. The authors, having limited their practice to endoscopic MIS surgery over the last 15-20 years, report on their experience gained during that period to relieve pain by endoscopically visualizing and treating unrecognized causative patho-anatomy in FBSS.7 Methods Thirty consecutive patients with FBSS presenting with back and leg pain that had supporting imaging diagnosis of lateral stenosis and /or residual / recurrent disc herniation, or whose pain complaint was supported by relief from diagnostic and therapeutic injections (Figure 1), were offered percutaneous transforaminal endoscopic discectomy and foraminoplasty over a repeat open procedure. Each patient sought consultation following a transient successful, partially successful or unsuccessful open translaminar surgical treatment for disc herniation or spinal stenosis. Endoscopic foraminoplasty was also performed to either decompress the bony foramen for foraminal stenosis, or foraminoplasty to allow for endoscopic visual examination of the affected traversing and exiting nerve roots in the axilla, also known as the �

Plagioclase nucleation and growth kinetics in a hydrous basaltic melt by decompression experiments

NASA Astrophysics Data System (ADS)

Arzilli, Fabio; Agostini, C.; Landi, P.; Fortunati, A.; Mancini, L.; Carroll, M. R.

2015-12-01

Isothermal single-step decompression experiments (at temperature of 1075 °C and pressure between 5 and 50 MPa) were used to study the crystallization kinetics of plagioclase in hydrous high-K basaltic melts as a function of pressure, effective undercooling (Δ T eff) and time. Single-step decompression causes water exsolution and a consequent increase in the plagioclase liquidus, thus imposing an effective undercooling (Δ T eff), accompanied by increased melt viscosity. Here, we show that the decompression process acts directly on viscosity and thermodynamic energy barriers (such as interfacial-free energy), controlling the nucleation process and favoring the formation of homogeneous nuclei also at high pressure (low effective undercoolings). In fact, this study shows that similar crystal number densities ( N a) can be obtained both at low and high pressure (between 5 and 50 MPa), whereas crystal growth processes are favored at low pressures (5-10 MPa). The main evidence of this study is that the crystallization of plagioclase in decompressed high-K basalts is more rapid than that in rhyolitic melts on similar timescales. The onset of the crystallization process during experiments was characterized by an initial nucleation event within the first hour of the experiment, which produced the largest amount of plagioclase. This nucleation event, at short experimental duration, can produce a dramatic change in crystal number density ( N a) and crystal fraction ( ϕ), triggering a significant textural evolution in only 1 h. In natural systems, this may affect the magma rheology and eruptive dynamics on very short time scales.

Resolution of extra-axial collections after decompressive craniectomy for ischemic stroke.

PubMed

Ropper, Alexander E; Nalbach, Stephen V; Lin, Ning; Dunn, Ian F; Gormley, William B

2012-02-01

Extra-axial fluid collections are known consequences of decompressive hemicraniectomy. Studies have examined these collections and their management. We retrospectively reviewed 12 consecutive patients who underwent decompressive hemicraniectomy for the treatment of malignant cerebral edema after infarction and evaluated the evolution, resolution and treatment of post-operative extra-axial fluid collections. All patients underwent standard-sized frontotemporoparietal hemicraniectomy with duraplasty as treatment for medically intractable malignant cerebral edema at an average of 3 days after the stroke (median 2 days). Their 30-day mortality was 25%. Three patients developed some extra-axial fluid collections after craniectomy: two patients developed the collections early in their post-operative course, 3 days and 5 days after the craniectomy. Both experienced spontaneous resolution of the collections without corrective cranioplasty or shunt placement at 34 days and 58 days after surgery. The third patient developed a collection 55 days after the operation related to a subgaleal bacterial infection. In the final analysis, 18% of patients developed extra-axial collections and all resolved spontaneously. The incidence of extra-axial collections after decompressive hemicraniectomy following ischemic stroke was lower in our retrospective series than has been reported by others. The collections resolved spontaneously, suggesting that early anticipatory, corrective treatment with cerebrospinal fluid diversion or cranioplasty may not be warranted. Copyright © 2011 Elsevier Ltd. All rights reserved.

High temporal resolution of extreme rainfall rate variability and the acoustic classification of rainfall

NASA Astrophysics Data System (ADS)

Nystuen, Jeffrey A.; Amitai, Eyal

2003-04-01

The underwater sound generated by raindrop splashes on a water surface is loud and unique allowing detection, classification and quantification of rainfall. One of the advantages of the acoustic measurement is that the listening area, an effective catchment area, is proportional to the depth of the hydrophone and can be orders of magnitude greater than other in situ rain gauges. This feature allows high temporal resolution of the rainfall measurement. A series of rain events with extremely high rainfall rates, over 100 mm/hr, is examined acoustically. Rapid onset and cessation of rainfall intensity are detected within the convective cells of these storms with maximum 5-s resolution values exceeding 1000 mm/hr. The probability distribution functions (pdf) for rainfall rate occurrence and water volume using the longer temporal resolutions typical of other instruments do not include these extreme values. The variance of sound intensity within different acoustic frequency bands can be used as an aid to classify rainfall type. Objective acoustic classification algorithms are proposed. Within each rainfall classification the relationship between sound intensity and rainfall rate is nearly linear. The reflectivity factor, Z, also has a linear relationship with rainfall rate, R, for each rainfall classification.

Women's experiences of daily life after anterior cervical decompression and fusion surgery: A qualitative interview study.

PubMed

Hermansen, Anna; Peolsson, Anneli; Kammerlind, Ann-Sofi; Hjelm, Katarina

2016-04-01

To explore and describe women's experiences of daily life after anterior cervical decompression and fusion surgery. Qualitative explorative design. Fourteen women aged 39-62 years (median 52 years) were included 1.5-3 years after anterior cervical decompression and fusion for cervical disc disease. Individual semi-structured interviews were analysed by qualitative content analysis with an inductive approach. The women described their experiences of daily life in 5 different ways: being recovered to various extents; impact of remaining symptoms on thoughts and feelings; making daily life work; receiving support from social and occupational networks; and physical and behavioural changes due to interventions and encounters with healthcare professionals. This interview study provides insight into women's daily life after anterior cervical decompression and fusion. Whilst the subjects improved after surgery, they also experienced remaining symptoms and limitations in daily life. A variety of mostly active coping strategies were used to manage daily life. Social support from family, friends, occupational networks and healthcare professionals positively influenced daily life. These findings provide knowledge about aspects of daily life that should be considered in individualized postoperative care and rehabilitation in an attempt to provide better outcomes in women after anterior cervical decompression and fusion.

Relative device stability of anterior versus axillary needle decompression for tension pneumothorax during casualty movement: Preliminary analysis of a human cadaver model.

PubMed

Leatherman, Matthew L; Held, Jenny M; Fluke, Laura M; McEvoy, Christian S; Inaba, Kenji; Grabo, Daniel; Martin, Matthew J; Earley, Angela S; Ricca, Robert L; Polk, Travis M

2017-07-01

Tension pneumothorax (tPTX) remains a significant cause of potentially preventable death in military and civilian settings. The current prehospital standard of care for tPTX is immediate decompression with a 14-gauge 8-cm angiocatheter; however, failure rates may be as high as 17% to 60%. Alternative devices, such as 10-gauge angiocatheter, modified Veress needle, and laparoscopic trocar, have shown to be potentially more effective in animal models; however, little is known about the relative insertional safety or mechanical stability during casualty movement. Seven soft-embalmed cadavers were intubated and mechanically ventilated. Chest wall thickness was measured at the second intercostal space at the midclavicular line (2MCL) and the fifth intercostal space along the anterior axillary line (5AAL). CO2 insufflation created a PTX, and needle decompression was then performed with a randomized device. Insertional depth was measured between hub and skin before and after simulated casualty transport. Thoracoscopy was used to evaluate for intrapleural placement and/or injury during insertion and after movement. Cadaver demographics, device displacement, device dislodgment, and injuries were recorded. Three decompressions were performed at each site (2MCL/5AAL), totaling 12 events per cadaver. Eighty-four decompressions were performed. Average cadaver age was 59 years, and body mass index was 24 kg/m. The CWT varied between cadavers because of subcutaneous emphysema, but the average was 39 mm at the 2MCL and 31 mm at the 5AAL. Following movement, the 2MCL site was more likely to become dislodged than the 5AAL (67% vs. 17%, p = 0.001). Median displacement also differed between 2MCL and 5AAL (23 vs. 2 mm, p = 0.001). No significant differences were noted in dislodgement or displacement between devices. Five minor lung injuries were noted at the 5AAL position. Preliminary results from this human cadaver study suggest the 5AAL position is a more stable and reliable location

Prevention of decompression sickness during a simulated space docking mission

NASA Technical Reports Server (NTRS)

Cooke, J. P.; Bollinger, R. R.; Richardson, B.

1975-01-01

This study has shown that repetitive exchanges between the Apollo space vehicle atmosphere of 100% oxygen at 5 psia (258 torr) and the Soyuz spacecraft atmosphere of 30% oxygen-70% nitrogen at 10 psia (533 torr), as simulated in altitude chambers, will not likely result in any form of decompression sickness. This conclusion is based upon the absence of any form of bends in seven crewmen who participated in 11 tests distributed over three 24-h periods. During each period, three transfers from the 5 to the 10 psia environments were performed by simulating passage through a docking module which served as an airlock where astronauts and cosmonauts first adapted to each other's cabin gases and pressures before transfer. Biochemical tests, subjective fatigue scores, and the complete absence of any form of pain were also indicative that decompression sickness should not be expected if this spacecraft transfer schedule is followed.

Use of computed tomography to assess volume change after endoscopic orbital decompression for Graves' ophthalmopathy.

PubMed

Schiff, Bradley A; McMullen, Caitlin P; Farinhas, Joaquim; Jackman, Alexis H; Hagiwara, Mari; McKellop, Jason; Lui, Yvonne W

2015-01-01

Orbital decompression is frequently performed in the management of patients with sight-threatening and disfiguring Graves' ophthalmopathy. The quantitative measurements of the change in orbital volume after orbital decompression procedures are not definitively known. Furthermore, the quantitative effect of septal deviation on volume change has not been previously analyzed. To provide quantitative measurement of orbital volume change after medial and inferior endoscopic decompression and describe a straightforward method of measuring this change using open-source technologies. A secondary objective was to assess the effect of septal deviation on orbital volume change. A retrospective review was performed on all patients undergoing medial and inferior endoscopic orbital decompression for Graves' ophthalmopathy at a tertiary care academic medical center. Pre-operative and post-operative orbital volumes were calculated from computed tomography (CT) data using a semi-automated segmenting technique and Osirix™, an open-source DICOM reader. Data were collected for pre-operative and post-operative orbital volumes, degree of septal deviation, time to follow-up scan, and individual patient Hertel scores. Nine patients (12 orbits) were imaged before and after decompression. Mean pre-operative orbital volume was 26.99 cm(3) (SD=2.86 cm(3)). Mean post-operative volume was 33.07 cm(3) (SD=3.96 cm(3)). The mean change in volume was 6.08 cm(3) (SD=2.31 cm(3)). The mean change in Hertel score was 4.83 (SD=0.75). Regression analysis of change in volume versus follow-up time to imaging indicates that follow-up time to imaging has little effect on change in volume (R=-0.2), and overall mean maximal septal deviation toward the operative side was -0.5mm. Negative values were attributed to deviation away form the operative site. A significant correlation was demonstrated between change in orbital volume and septal deviation distance site (R=0.66), as well as between change in orbital

Successful Treatment of Early Talar Osteonecrosis by Core Decompression Combined with Intraosseous Stem Cell Injection: A Case Report.

PubMed

Nevalainen, Mika T; Repo, Jussi P; Pesola, Maija; Nyrhinen, Jukka P

2018-01-01

Osteonecrosis of the talus is a fairly rare condition. Many predisposing factors have been identified including previous trauma, use of corticosteroids, alcoholism, and smoking. As a gold standard, magnetic resonance imaging (MRI) is the most sensitive and specific diagnostic examination to detect osteonecrosis. While many treatment options for talar osteonecrosis exist, core decompression is suggested on young patients with good outcome results. More recently, intraosseous stem cell and platelet-rich plasma (PRP) injection has been added to the core decompression procedure. We report a successful treatment of early talar osteonecrosis ARCO I (Association Research Circulation Osseous) by core decompression combined with stem cell and PRP injection. On 3-month and 15-month follow-up, MRI showed complete resolution of the osteonecrotic changes together with clinical improvement. This modified technique is a viable treatment option for early talar osteonecrosis. Nevertheless, future prospects should include a study comparing this combined technique with plain core decompression.

Colonic Fermentation Promotes Decompression sickness in Rats

PubMed Central

de Maistre, Sébastien; Vallée, Nicolas; Gempp, Emmanuel; Lambrechts, Kate; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

2016-01-01

Massive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body’s H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental dive, 93 fasting rats were force-fed, half of them with mannitol and the other half with water. Exhaled hydrogen was measured before and after force-feeding. Following the hyperbaric exposure, we looked for signs of DCS. A higher incidence of DCS was found in rats force-fed with mannitol than in those force-fed with water (80%, [95%CI 56, 94] versus 40%, [95%CI 19, 64], p < 0.01). In rats force-fed with mannitol, metronidazole pretreatment reduced the incidence of DCS (33%, [95%CI 15, 57], p = 0.005) at the same time as it inhibited colonic fermentation (14 ± 35 ppm versus 118 ± 90 ppm, p = 0.0001). Pre-diveingestion of mannitol increased the incidence of DCS in fasting rats when colonic fermentation peaked during the decompression phase. More generally, colonic fermentation in rats on a normal diet could promote DCS through endogenous hydrogen production. PMID:26853722

Changes in foraminal area with anterior decompression versus keyhole foraminotomy in the cervical spine: a biomechanical investigation.

PubMed

Nguyen, Jacqueline; Chu, Bryant; Kuo, Calvin C; Leasure, Jeremi M; Ames, Christopher; Kondrashov, Dimitriy

2017-12-01

OBJECTIVE Anterior cervical discectomy and fusion (ACDF) with or without partial uncovertebral joint resection (UVR) and posterior keyhole foraminotomy are established operative procedures to treat cervical disc degeneration and radiculopathy. Studies have demonstrated reliable results with each procedure, but none have compared the change in neuroforaminal area between indirect and direct decompression techniques. The purpose of this study was to determine which cervical decompression method most consistently increases neuroforaminal area and how that area is affected by neck position. METHODS Eight human cervical functional spinal units (4 each of C5-6 and C6-7) underwent sequential decompression. Each level received the following surgical treatment: bilateral foraminotomy, ACDF, ACDF + partial UVR, and foraminotomy + ACDF. Multidirectional pure moment flexibility testing combined with 3D C-arm imaging was performed after each procedure to measure the minimum cross-sectional area of each foramen in 3 different neck positions: neutral, flexion, and extension. RESULTS Neuroforaminal area increased significantly with foraminotomy versus intact in all positions. These area measurements did not change in the ACDF group through flexion-extension. A significant decrease in area was observed for ACDF in extension (40 mm 2 ) versus neutral (55 mm 2 ). Foraminotomy + ACDF did not significantly increase area compared with foraminotomy in any position. The UVR procedure did not produce any changes in area through flexion-extension. CONCLUSIONS All procedures increased neuroforaminal area. Foraminotomy and foraminotomy + ACDF produced the greatest increase in area and also maintained the area in extension more than anterior-only procedures. The UVR procedure did not significantly alter the area compared with ACDF alone. With a stable cervical spine, foraminotomy may be preferable to directly decompress the neuroforamen; however, ACDF continues to play an important role for

Gender and Decompression Sickness: A Critical Review and Analysis

NASA Technical Reports Server (NTRS)

2004-01-01

The author addressed the following questions: are women at greater risk of decompression sickness and venous gas emboli at certain times in their reproductive cycle, is risk modified by the use of birth control pills (BCP), and is there a difference in overall risk between men and women under the same decompression dose? The summary considers information from the few abstracts and reports that were available. Except for the observation of more Type II DCS in women, particularly in women who fly after diving, there was no compelling evidence of a difference in DCS risk between men and women SCUBA divers. Many women that presented with DCS symptoms seemed to be in or near menses, with statistically fewer cases reported as time increased from menses. There was no compelling evidence that the use of BCP in SCUBA divers increases the risk of DCS. There were insufficient data about VGE from SCUBA diving to make any conclusion about the incidence of VGE and gender. In contrast, there were ample data about VGE from research in altitude chambers. Women produced less VGE and less Grade IV VGE compared to men under the same decompression dose, certainly when resting oxygen prebreathe (PB) was performed prior to ascent to altitude. Dual-cycle ergometry exercise during PB tends to reduce the differences in VGE between men and women. There was no compelling evidence that the risk of altitude DCS was different between men and women. However, a large number of DCS cases were associated with menses, and the use of BCP did seem to put women at a slightly greater risk than those that did not use BCP. There were substantial observations that women comprised a larger number of difficult cases that required complicated medical management.

Decompression tables for inside chamber attendants working at altitude.

PubMed

Bell, James; Thombs, Paul A; Davison, William J; Weaver, Lindell K

2014-01-01

Hyperbaric oxygen (HBO2) multiplace chamber inside attendants (IAs) are at risk for decompression sickness (DCS). Standard decompression tables are formulated for sea-level use, not for use at altitude. At Presbyterian/St. Luke's Medical Center (Denver, Colorado, 5,924 feet above sea level) and Intermountain Medical Center (Murray, Utah, 4,500 feet), the decompression obligation for IAs is managed with U.S. Navy Standard Air Tables corrected for altitude, Bühlmann Tables, and the Nobendem© calculator. IAs also breathe supplemental oxygen while compressed. Presbyterian/St. Luke's (0.83 atmospheres absolute/atm abs) uses gauge pressure, uncorrected for altitude, at 45 feet of sea water (fsw) (2.2 atm abs) for routine wound care HBO2 and 66 fsw (2.8 atm abs) for carbon monoxide/cyanide poisoning. Presbyterian/St. Luke's provides oxygen breathing for the IAs at 2.2 atm abs. At Intermountain (0.86 atm abs), HBO2 is provided at 2.0 atm abs for routine treatments and 3.0 atm abs for carbon monoxide poisoning. Intermountain IAs breathe intermittent 50% nitrogen/50% oxygen at 3.0 atm abs and 100% oxygen at 2.0 atm abs. The chamber profiles include a safety stop. From 1990-2013, Presbyterian/St. Luke's had 26,900 total IA exposures: 25,991 at 45 fsw (2.2 atm abs) and 646 at 66 fsw (2.8 atm abs); there have been four cases of IA DCS. From 2008-2013, Intermountain had 1,847 IA exposures: 1,832 at 2 atm abs and 15 at 3 atm abs, with one case of IA DCS. At both facilities, DCS incidents occurred soon after the chambers were placed into service. Based on these results, chamber inside attendant risk for DCS at increased altitude is low when the inside attendants breathe supplemental oxygen.

Piezosurgery for orbital decompression surgery in thyroid associated orbitopathy.

PubMed

Ponto, Katharina A; Zwiener, Isabella; Al-Nawas, Bilal; Kahaly, George J; Otto, Anna F; Karbach, Julia; Pfeiffer, Norbert; Pitz, Susanne

2014-12-01

The purpose of this study was to assess a piezosurgical device as a novel tool for bony orbital decompression surgery. At a multidisciplinary orbital center, 62 surgeries were performed in 40 patients with thyroid associated orbitopathy (TAO). Within this retrospective case-series, we analyzed the medical records of these consecutive unselected patients. The reduction of proptosis was the main outcome measure. Indications for a two (n = 27, 44%) or three wall (35, 56%) decompression surgery were proptosis (n = 50 orbits, 81%) and optic neuropathy (n = 12, 19%). Piezosurgery enabled precise bone cuts without intraoperative complications. Proptosis decreased from 23.6 ± 2.8 mm (SD) by 3 mm (95% CI: -3.6 to -2.5 mm) after surgery and stayed stable at 3 months (-3 mm, 95% CI: -3.61 to -2.5 mm, p < 0.001, respectively). The effect was higher in those with preoperatively higher values (>24 mm versus ≤ 24 mm: -3.4 mm versus -2.81 mm before discharge from hospital and -4.1 mm versus -2.1 mm at 3 months: p < 0.001, respectively). After a mean long-term follow-up period of 14.6 ± 10.4 months proptosis decreased by further -0.7 ± 2.0 mm (p < 0.001). Signs of optic nerve compression improved after surgery. Infraorbital hypesthesia was present in 11 of 21 (52%) orbits 3 months after surgery. The piezosurgical device is a useful tool for orbital decompression surgery in TAO. By cutting bone selectively, it is precise and reduces the invasiveness of surgery. Nevertheless, no improvement in outcome or reduction in morbidity over conventional techniques has been shown so far. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Delayed Unilateral Soft Palate Palsy without Vocal Cord Involvement after Microvascular Decompression for Hemifacial Spasm

PubMed Central

Park, Jae Han; Jo, Kyung Il

2013-01-01

Microvascular decompression is a very effective and relatively safe surgical modality in the treatment of hemifacial spasm. But rare debilitating complications have been reported such as cranial nerve dysfunctions. We have experienced a very rare case of unilateral soft palate palsy without the involvement of vocal cord following microvascular decompression. A 33-year-old female presented to our out-patient clinic with a history of left hemifacial spasm for 5 years. On postoperative 5th day, patient started to exhibit hoarsness with swallowing difficulty. Symptoms persisted despite rehabilitation. Various laboratory work up with magnetic resonance image showed no abnormal lesions. Two years after surgery patient showed complete recovery of unitaleral soft palate palsy. Various etiologies of unilateral soft palate palsy are reviewed as the treatment and prognosis differs greatly on the cause. Although rare, it is important to keep in mind that such complication could occur after microvascular decompression. PMID:24003372

Hemicraniectomy after middle cerebral artery infarction with life-threatening Edema trial (HAMLET). Protocol for a randomised controlled trial of decompressive surgery in space-occupying hemispheric infarction.

PubMed

Hofmeijer, Jeannette; Amelink, G Johan; Algra, Ale; van Gijn, Jan; Macleod, Malcolm R; Kappelle, L Jaap; van der Worp, H Bart

2006-09-11

Patients with a hemispheric infarct and massive space-occupying brain oedema have a poor prognosis. Despite maximal conservative treatment, the case fatality rate may be as high as 80%, and most survivors are left severely disabled. Non-randomised studies suggest that decompressive surgery reduces mortality substantially and improves functional outcome of survivors. This study is designed to compare the efficacy of decompressive surgery to improve functional outcome with that of conservative treatment in patients with space-occupying supratentorial infarction The study design is that of a multi-centre, randomised clinical trial, which will include 112 patients aged between 18 and 60 years with a large hemispheric infarct with space-occupying oedema that leads to a decrease in consciousness. Patients will be randomised to receive either decompressive surgery in combination with medical treatment or best medical treatment alone. Randomisation will be stratified for the intended mode of conservative treatment (intensive care or stroke unit care). The primary outcome measure will be functional outcome, as determined by the score on the modified Rankin Scale, at one year.

2014 Decompression Sickness/Extravehicular Activity Risks Standing Review Panel

NASA Technical Reports Server (NTRS)

Steinberg, Susan

2015-01-01

The 2014 Decompression Sickness (DCS)/Extravehicular Activity (EVA) Risks Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on November 4 - 5, 2014. The SRP reviewed the updated Evidence Reports for The Risk of Decompression Sickness (from here on referred to as the 2014 DCS Evidence Report) and the Risk of Injury and Compromised Performance due to EVA Operations (from here on referred to as the 2014 EVA Evidence Report), as well as the Research Plans for these Risks. The SRP appreciated the time and effort that the DCS and EVA disciplines put into their review documents and presentations. The SRP felt that the 2014 DCS Evidence Report and the 2014 EVA Evidence Reports were very thorough and addressed the majority of the known DCS and EVA issues. The researchers at NASA Johnson Space Center (JSC) have the knowledge base to deal with the DCS and EVA issues. Overall, the SRP thinks the DCS and EVA research teams have compiled excellent reports which address the majority of the literature and background information.

Percutaneous Laser Disc Decompression (PLDD): Experience and Results From Multiple Centers and 19,880 Procedures

NASA Astrophysics Data System (ADS)

Paolo Tassi, Gian; Choy, Daniel S. J.; Hellinger, Johannes; Hellinger, Stefan; Lee, Sang-Ho

2010-05-01

In mid-February 1986, Peter Ascher and Daniel Choy performed the first Percutaneous Laser Disc Decompression (PLDD) at the Neurosurgical Department, University of Graz, Graz, Austria. It was planned to deliver 1000 joules with a Nd:YAG laser to a herniated L4-5 disc causing sciatica. At 600 joules the procedure was terminated because the pain was gone. Since then, PLDD has spread all over the world, with procedures being performed in the entire spine except for T1-T4 because these discs do not permit percutaneous access with a needle. The success rate has ranged from 70 to 89%, and the complication rate, chiefly discitis, from 0.3 to 1.0%. When successful, return to normal work averages one week. Long term follow-up to 23 years yields a recurrence rate of 4-5%.

Tensile strength and failure mechanisms of tantalum at extreme strain rates

NASA Astrophysics Data System (ADS)

Hahn, Eric; Fensin, Saryu; Germann, Timothy; Meyers, Marc

Non-equilibrium molecular dynamics simulations are used to probe the tensile response of monocrystalline, bicrystalline, and nanocrystalline tantalum over six orders of magnitude of strain rate. Our analysis of the strain rate dependence of strength is extended to over nine orders of magnitude by bridging the present simulations to recent laser-driven shock experiments. Tensile strength shows a power-law dependence with strain rate over this wide range, with different relationships depending on the initial microstructure and active deformation mechanism. At high strain rates, multiple spall events occur independently and continue to occur until communication occurs by means of relaxation waves. Temperature plays a significant role in the reduction of spall strength as the initial shock required to achieve such large strain rates also contributes to temperature rise, through pressure-volume work as well as visco-plastic heating, which leads to softening and sometimes melting upon release. At ultra-high strain rates, those approaching or exceeding the atomic vibrational frequency, spall strength saturates at the ultimate cohesive strength of the material. UC Research Laboratories Grant (09-LR-06-118456-MEYM); Department of Energy NNSA/SSAP (DE-NA0002080); DOE ASCR Exascale Co-design Center for Materials in Extreme Environments.

A metastable liquid melted from a crystalline solid under decompression

NASA Astrophysics Data System (ADS)

Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Kono, Yoshio; Park, Changyong; Kenney-Benson, Curtis; Shen, Guoyin

2017-01-01

A metastable liquid may exist under supercooling, sustaining the liquid below the melting point such as supercooled water and silicon. It may also exist as a transient state in solid-solid transitions, as demonstrated in recent studies of colloidal particles and glass-forming metallic systems. One important question is whether a crystalline solid may directly melt into a sustainable metastable liquid. By thermal heating, a crystalline solid will always melt into a liquid above the melting point. Here we report that a high-pressure crystalline phase of bismuth can melt into a metastable liquid below the melting line through a decompression process. The decompression-induced metastable liquid can be maintained for hours in static conditions, and transform to crystalline phases when external perturbations, such as heating and cooling, are applied. It occurs in the pressure-temperature region similar to where the supercooled liquid Bi is observed. Akin to supercooled liquid, the pressure-induced metastable liquid may be more ubiquitous than we thought.

A metastable liquid melted from a crystalline solid under decompression

PubMed Central

Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Kono, Yoshio; Park, Changyong; Kenney-Benson, Curtis; Shen, Guoyin

2017-01-01

A metastable liquid may exist under supercooling, sustaining the liquid below the melting point such as supercooled water and silicon. It may also exist as a transient state in solid–solid transitions, as demonstrated in recent studies of colloidal particles and glass-forming metallic systems. One important question is whether a crystalline solid may directly melt into a sustainable metastable liquid. By thermal heating, a crystalline solid will always melt into a liquid above the melting point. Here we report that a high-pressure crystalline phase of bismuth can melt into a metastable liquid below the melting line through a decompression process. The decompression-induced metastable liquid can be maintained for hours in static conditions, and transform to crystalline phases when external perturbations, such as heating and cooling, are applied. It occurs in the pressure–temperature region similar to where the supercooled liquid Bi is observed. Akin to supercooled liquid, the pressure-induced metastable liquid may be more ubiquitous than we thought. PMID:28112152

Statistical comparison of pooled nitrogen washout data of various altitude decompression response groups

NASA Technical Reports Server (NTRS)

Edwards, B. F.; Waligora, J. M.; Horrigan, D. J., Jr.

1985-01-01

This analysis was done to determine whether various decompression response groups could be characterized by the pooled nitrogen (N2) washout profiles of the group members, pooling individual washout profiles provided a smooth time dependent function of means representative of the decompression response group. No statistically significant differences were detected. The statistical comparisons of the profiles were performed by means of univariate weighted t-test at each 5 minute profile point, and with levels of significance of 5 and 10 percent. The estimated powers of the tests (i.e., probabilities) to detect the observed differences in the pooled profiles were of the order of 8 to 30 percent.

The effect of exercise on venous gas emboli and decompression sickness in human subjects at 4.3 psia

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Waligora, James M.; Horrigan, David J., Jr.; Hadley, Arthur T., III

1987-01-01

The contribution of upper body exercise to altitude decompression sickness while at 4.3 psia after 3.5 or 4.0 hours of 100% oxygen prebreathing at 14.7 psia was determined by comparing the incidence and patterns of venous gas emboli (VGE), and the incidence of Type 1 decompression sickness (DCS) in 43 exercising male subjects and 9 less active male Doppler Technicians (DT's). Each subject exercised for 4 minutes at each of 3 exercise stations while at 4.3 psia. An additional 4 minutes were spent monitoring for VGE by the DT while the subject was supine on an examination cot. In the combined 3.5 and 4.0 hour oxygen prebreathe data, 13 subjects complained of Type 1 DCS compared to 9 complaints from DT's. VGE were detected in 28 subjects compared to 14 detections from DT's. A chi-square analysis of proportions showed no statistically significantly difference in the incidence of Type 1 DCS or VGE between the two groups; however, the average time to detect VGE and to report Tyep 1 DCS symptoms were statistically different. It was concluded that 4 to 6 hours of upper body exercise at metabolic rates simulating EVA metabolic rates hastens the initial detection of VGE and the time to report Type 1 DCS symptoms as compared to DT's.

Active compression-decompression cardiopulmonary resuscitation (CPR) versus standard CPR for cardiac arrest patients: a meta-analysis

PubMed Central

Luo, Xu-rui; Zhang, Hui-li; Chen, Geng-jin; Ding, Wen-shu; Huang, Liang

2013-01-01

BACKGROUND: Active compression-decompression cardiopulmonary resuscitation (ACDCPR) has been popular in the treatment of patients with cardiac arrest (CA). However, the effect of ACD-CPR versus conventional standard CPR (S-CRP) is contriversial. This study was to analyze the efficacy and safety of ACD-CPR versus S-CRP in treating CA patients. METHODS: Randomized or quasi-randomized controlled trials published from January 1990 to March 2011 were searched with the phrase “active compression-decompression cardiopulmonary resuscitation and cardiac arrest” in PubMed, EmBASE, and China Biomedical Document Databases. The Cochrane Library was searched for papers of meta-analysis. Restoration of spontaneous circulation (ROSC) rate, survival rate to hospital admission, survival rate at 24 hours, and survival rate to hospital discharge were considered primary outcomes, and complications after CPR were viewed as secondary outcomes. Included studies were critically appraised and estimates of effects were calculated according to the model of fixed or random effects. Inconsistency across the studies was evaluated using the I2 statistic method. Sensitivity analysis was made to determine statistical heterogeneity. RESULTS: Thirteen studies met the criteria for this meta-analysis. The studies included 396 adult CA patients treated by ACD-CPR and 391 patients by S-CRP. Totally 234 CA patients were found out hospitals, while the other 333 CA patients were in hospitals. Two studies were evaluated with high-quality methodology and the rest 11 studies were of poor quality. ROSC rate, survival rate at 24 hours and survival rate to hospital discharge with favorable neurological function indicated that ACD-CPR is superior to S-CRP, with relative risk (RR) values of 1.39 (95% CI 0.99–1.97), 1.94 (95% CI 1.45–2.59) and 2.80 (95% CI 1.60–5.24). No significant differences were found in survival rate to hospital admission and survival rate to hospital discharge for ACD-CPR versus S

Chest Wall Thickness and Decompression Failure: A Systematic Review and Meta-analysis Comparing Anatomic Locations in Needle Thoracostomy

PubMed Central

Laan, Danuel V.; Vu, Trang Diem N.; Thiels, Cornelius A.; Pandian, T. K.; Schiller, Henry J.; Murad, M. Hassan; Aho, Johnathon M.

2015-01-01

Introduction Current Advanced Trauma Life Support guidelines recommend decompression for thoracic tension physiology using a 5-cm angiocatheter at the second intercostal space (ICS) on the midclavicular line (MCL). High failure rates occur. Through systematic review and meta-analysis, we aimed to determine the chest wall thickness (CWT) of the 2nd ICS-MCL, the 4th/5th ICS at the anterior axillary line (AAL), the 4th/5th ICS mid axillary line (MAL) and needle thoracostomy failure rates using the currently recommended 5-cm angiocatheter. Methods A comprehensive search of several databases from their inception to July 24, 2014 was conducted. The search was limited to the English language, and all study populations were included. Studies were appraised by two independent reviewers according to a priori defined PRISMA inclusion and exclusion criteria. Continuous outcomes (CWT) were evaluated using weighted mean difference and binary outcomes (failure with 5-cm needle) were assessed using incidence rate. Outcomes were pooled using the random-effects model. Results The search resulted in 34,652 studies of which 15 were included for CWT analysis, 13 for NT effectiveness. Mean CWT was 42.79 mm (95% CI, 38.78–46.81) at 2nd ICS-MCL, 39.85 mm (95% CI, 28.70–51.00) at MAL, and 34.33 mm (95% CI, 28.20–40.47) at AAL (P=0.08). Mean failure rate was 38% (95% CI, 24–54) at 2nd ICS-MCL, 31% (95% CI, 10–64) at MAL, and 13% (95% CI, 8–22) at AAL (P=0.01). Conclusion Evidence from observational studies suggests that the 4th/5th ICS-AAL has the lowest predicted failure rate of needle decompression in multiple populations. PMID:26724173

Chest wall thickness and decompression failure: A systematic review and meta-analysis comparing anatomic locations in needle thoracostomy.

PubMed

Laan, Danuel V; Vu, Trang Diem N; Thiels, Cornelius A; Pandian, T K; Schiller, Henry J; Murad, M Hassan; Aho, Johnathon M

2016-04-01

Current Advanced Trauma Life Support guidelines recommend decompression for thoracic tension physiology using a 5-cm angiocatheter at the second intercostal space (ICS) on the midclavicular line (MCL). High failure rates occur. Through systematic review and meta-analysis, we aimed to determine the chest wall thickness (CWT) of the 2nd ICS-MCL, the 4th/5th ICS at the anterior axillary line (AAL), the 4th/5th ICS mid axillary line (MAL) and needle thoracostomy failure rates using the currently recommended 5-cm angiocatheter. A comprehensive search of several databases from their inception to July 24, 2014 was conducted. The search was limited to the English language, and all study populations were included. Studies were appraised by two independent reviewers according to a priori defined PRISMA inclusion and exclusion criteria. Continuous outcomes (CWT) were evaluated using weighted mean difference and binary outcomes (failure with 5-cm needle) were assessed using incidence rate. Outcomes were pooled using the random-effects model. The search resulted in 34,652 studies of which 15 were included for CWT analysis, 13 for NT effectiveness. Mean CWT was 42.79 mm (95% CI, 38.78-46.81) at 2nd ICS-MCL, 39.85 mm (95% CI, 28.70-51.00) at MAL, and 34.33 mm (95% CI, 28.20-40.47) at AAL (P=.08). Mean failure rate was 38% (95% CI, 24-54) at 2nd ICS-MCL, 31% (95% CI, 10-64) at MAL, and 13% (95% CI, 8-22) at AAL (P=.01). Evidence from observational studies suggests that the 4th/5th ICS-AAL has the lowest predicted failure rate of needle decompression in multiple populations. Level 3 SR/MA with up to two negative criteria. Therapeutic. Copyright © 2015 Elsevier Ltd. All rights reserved.

Multiple Small Diameter Drillings Increase Femoral Neck Stability Compared with Single Large Diameter Femoral Head Core Decompression Technique for Avascular Necrosis of the Femoral Head.

PubMed

Brown, Philip J; Mannava, Sandeep; Seyler, Thorsten M; Plate, Johannes F; Van Sikes, Charles; Stitzel, Joel D; Lang, Jason E

2016-10-26

Femoral head core decompression is an efficacious joint-preserving procedure for treatment of early stage avascular necrosis. However, postoperative fractures have been described which may be related to the decompression technique used. Femoral head decompressions were performed on 12 matched human cadaveric femora comparing large 8mm single bore versus multiple 3mm small drilling techniques. Ultimate failure strength of the femora was tested using a servo-hydraulic material testing system. Ultimate load to failure was compared between the different decompression techniques using two paired ANCOVA linear regression models. Prior to biomechanical testing and after the intervention, volumetric bone mineral density was determined using quantitative computed tomography to account for variation between cadaveric samples and to assess the amount of bone disruption by the core decompression. Core decompression, using the small diameter bore and multiple drilling technique, withstood significantly greater load prior to failure compared with the single large bore technique after adjustment for bone mineral density (p< 0.05). The 8mm single bore technique removed a significantly larger volume of bone compared to the 3mm multiple drilling technique (p< 0.001). However, total fracture energy was similar between the two core decompression techniques. When considering core decompression for the treatment of early stage avascular necrosis, the multiple small bore technique removed less bone volume, thereby potentially leading to higher load to failure.

Long-term effects of core decompression by drilling. Demonstration of bone healing and vessel ingrowth in an animal study.

PubMed

Simank, H G; Graf, J; Kerber, A; Wiedmaier, S

1997-01-01

Avascular necrosis of the femoral head is associated with bone marrow hyperpression. Although core decompression by drilling is an accepted treatment regimen, until today no experimental results exist concerning the physiological effects of this procedure. Published clinical data are controversial. In an animal study marrow decompression was carried out by drilling of both hips in 18 healthy male sheep. In the right hip of each animal a resorbable stent was implanted in order to prolong the duration of core decompression. Over a time period of 24 weeks the effects were studied by measurement of the intraosseous pressure, by the plastination method and by morphological examination with light and electron microscopy. Bone drilling is a procedure of high short-time efficacy in decompressing the bone marrow. But decompression lasts only for a short time period. Three weeks postoperatively the drill channel is sealed by hematoma and fibrous tissue in both hips (with/without stent) and no significant decompressive effect is measured. Ingrowth of vessels along the drill channel is found in all hips after a time period of 3 weeks. These vessels originate from the periosteum as well as from the bone marrow and form temporary anastomoses between the periostal-diaphyseal-metaphyseal and the epiphyseal-physeal circulatory system. In conclusion, for the first time an anastomosis induced by drilling between both circulatory systems of bone is demonstrated and the importance of the periosteum is confirmed. The time of decreased core pressure induced by drilling is too short for substitution of a necrotic area and could be the explanation of the inferior clinical results of the procedure.

Multifractal comparison of the extremes of rain rates and integrated vapour content

NASA Astrophysics Data System (ADS)

Gires, Auguste; Ni, Vincent; Bosser, Pierre; Tchiguirinskaia, Ioulia; Schertzer, Daniel

2015-04-01

Rainfall extremes are studied through the analyse of three related fields measured with the help of co-located devices installed in the roof of the Ecole des Ponts ParisTech building: (i) Integrated Water Vapour (IWV); it corresponds the amount of water vapour present in the vertical columns between a GPS ground receiver and corresponding satellites. It is estimated from the time shift between the expected duration the signal needs to reach the receiver (the two positions are known) and the actual one (ii) Rain rate measured by three optical disdrometers of two different types (Campbell Scientific PWS100 and OTT Parsivel2) (iii) Relative humidity measured by a dedicated sensor First the correlations between these quantities during significant events is analysed. It appears that although IWV tends to decrease (vapour condense to form drops that fall) and relative humidity to increase during a rainfall event, it turns out difficult to quantitatively characterize this link. It is possibly due to the fact that the scale gap between a punctual measure for the rain rate and an average over a few km height column for the IWV is too large. Finally the scaling features of these three fields are investigated with the help of the Universal Multifractal framework which has been extensively used to analyse and simulate geophysical fields extremely variable over wide ranges of scales. Only three parameters are used to characterize variability across scales: C1 the mean intermittency, alpha the multifractality index and H the non-conservative exponent. Retrieved features are compared and the notion of maximum observable singularity is used to quantify the extremes of the various fields. Authors acknowledge the financial support of the Interreg IV NEW RainGain project (www.raingain.eu) and the chair "hydrology for resilient cities" sponsored by Véolia, and the Climate-KIC Blue Green Dream project (bgd.org.uk/).

Anterior decompression with fusion versus posterior decompression with fusion for massive cervical ossification of the posterior longitudinal ligament with a ≥50% canal occupying ratio: a multicenter retrospective study.

PubMed

Yoshii, Toshitaka; Sakai, Kenichiro; Hirai, Takashi; Yamada, Tsuyoshi; Inose, Hiroyuki; Kato, Tsuyoshi; Enomoto, Mitsuhiro; Tomizawa, Shoji; Kawabata, Shigenori; Arai, Yoshiyasu; Okawa, Atsushi

2016-11-01

Previous studies have shown that compared with laminoplasty, anterior decompression with fusion (ADF) is superior for postoperative neurologic improvement in patients with massive cervical ossification of the posterior longitudinal ligament (OPLL) with a ≥50% canal occupying ratio. However, it is unknown which method, ADF or posterior decompression with fusion (PDF), is more effective for the treatment of massive OPLL. This study aimed to investigate the surgical outcomes of ADF and PDF for the treatment of massive OPLL. A multicenter retrospective case-control study was carried out. A total of 61 OPLL patients with a ≥50% canal occupying ratio were included in this study. The mean age of the patients was 60.9 years (49 males and 12 females); 39 patients (31 males and 8 females, average age 61.1 years) underwent ADF, and 22 patients underwent PDF (18 males and 4 females, average age 60.6 years). The data collected from both groups included age, gender, neurologic symptoms evaluated based on the Japanese Orthopedic Association score, neck pain assessed using the visual analogue scale, and radiographic parameters, including cervical lordosis and the OPLL canal occupying ratio. Clinical and radiological outcomes were compared between the ADF and PDF groups with a minimum of 2 years follow-up. There were no significant differences in the postoperative neurologic recovery rate between the two groups. However, in patients with kyphotic alignment (C2-C7 angle <0 degrees), the recovery rate was higher in the ADF group. Postoperative cervical pain was greater in the PDF group. The improvement in cervical alignment at C2-C7 was greater in the ADF group. The operating time was longer in the ADF group, whereas the intraoperative blood loss was greater in the PDF group. Approach-related complications were more frequently observed in the ADF group than in the PDF group. The present study demonstrated that the postoperative recovery rate was similar in the ADF and PDF group

Reducing intraocular-pressure spike after intravitreal-bevacizumab injection with ocular decompression using a sterile cotton swab soaked in proparacaine 0.5%: A quasi-experimental study.

PubMed

Qureshi, Naveed A; Mansoor, Hassan; Ahmad, Sabihuddin; Zafar, Sarah; Asif, Muhammad

2016-01-01

The study was conducted to determine the effect of preinjection ocular decompression by a cotton swab soaked in local anesthetic on the immediate postinjection rise in intraocular pressure (IOP) after intravitreal bevacizumab (IVB). A nonrandomized, quasi-experimental interventional study was conducted at Al-Shifa Trust Eye Hospital, Pakistan, from August 1, 2013 to July 31, 2014. One hundred ( n = 100) patients receiving 0.05-mL IVB injection for the first time were assigned to two preinjection anesthetic methods: one with ocular decompression using a sterile cotton swab soaked in proparacaine 0.5%, and the other without ocular decompression using proparacaine 0.5% eyedrops. The IOP was recorded in the eye receiving IVB at three time intervals: Time 1 (preinjection), Time 2 (immediately after injection), and Time 3 (30 minutes after injection). There was a significant difference in the mean IOP change (between Time 1 and Time 2) for the group injected with ocular decompression [ M = 1.00, standard deviation (SD) = 1.47] and the group injected without ocular decompression ( M = 5.00, SD = 2.38; t (68) = 9.761, p < 0.001). There was also a significant difference in the mean IOP change (between Time 1 and Time 3) for the group injected with ocular decompression ( M = 0.428, SD = 1.58) and the group injected without ocular decompression ( M = 4.318, SD = 3.34; t (58) = 7.111, p < 0.001). Patients receiving IVB injections with ocular-decompression soaking in proparacaine 0.5% experience significantly lower postinjection IOP spike, and that too for a considerably shorter duration as compared to those receiving IVB without ocular decompression.

Recovery of TES-MEPs during surgical decompression of the spine: a case series of eight patients.

PubMed

Visser, Jetze; Verra, Wiebe C; Kuijlen, Jos M; Horsting, Philip P; Journée, Henricus L

2014-12-01

This study aimed to illustrate the recovery of transcranial electrical stimulation motor evoked potentials during surgical decompression of the spinal cord in patients with impaired motor function preoperatively. Specific attention was paid to the duration of neurologic symptoms before surgery and the postoperative clinical recovery. A case series of eight patients was selected from a cohort of 74 patients that underwent spine surgery. The selected patients initially had low or absent transcranial electrical stimulation motor evoked potentials followed by a significant increase after surgical decompression of the spinal cord. A significant intraoperative increase in amplitude of motor evoked potentials was detected after decompression of the spinal cord or cauda equina in patients suffering from spinal canal stenosis (n = 2), extradural meningioma (n = 3), or a herniated nucleus polposus (n = 3). This was related to an enhanced neurologic outcome only if patients (n = 6) had a short onset (less than ½ year) of neurologic impairment before surgery. In patients with a short onset of neurologic impairment because of compression of the spinal cord or caudal fibers, an intraoperative recovery of transcranial electrical stimulation motor evoked potentials can indicate an improvement of motor function postoperatively. Therefore, transcranial electrical stimulation motor evoked potentials can be considered as a useful tool to the surgeon to monitor the quality of decompression of the spinal cord.

Hazards of high altitude decompression sickness during falls in barometric pressure from 1 atm to a fraction thereof

NASA Technical Reports Server (NTRS)

Genin, A. M.

1980-01-01

Various tests related to studies concerning the effects of decompression sicknesses at varying pressure levels and physical activity are described. The tests indicate that there are no guarantees of freedom from decompression sicknesses when man transitions from a normally oxygenated normobaric nitrogen-oxygen atmosphere into an environment having a 0.4 atm or lower pressure and he is performing physical work.

The impact of decompression with instrumentation on local failure following spine stereotactic radiosurgery.

PubMed

Miller, Jacob A; Balagamwala, Ehsan H; Berriochoa, Camille A; Angelov, Lilyana; Suh, John H; Benzel, Edward C; Mohammadi, Alireza M; Emch, Todd; Magnelli, Anthony; Godley, Andrew; Qi, Peng; Chao, Samuel T

2017-10-01

OBJECTIVE Spine stereotactic radiosurgery (SRS) is a safe and effective treatment for spinal metastases. However, it is unknown whether this highly conformal radiation technique is suitable at instrumented sites given the potential for microscopic disease seeding. The authors hypothesized that spinal decompression with instrumentation is not associated with increased local failure (LF) following SRS. METHODS A 2:1 propensity-matched retrospective cohort study of patients undergoing SRS for spinal metastasis was conducted. Patients with less than 1 month of radiographic follow-up were excluded. Each SRS treatment with spinal decompression and instrumentation was propensity matched to 2 controls without decompression or instrumentation on the basis of demographic, disease-related, dosimetric, and treatment-site characteristics. Standardized differences were used to assess for balance between matched cohorts. The primary outcome was the 12-month cumulative incidence of LF, with death as a competing risk. Lesions demonstrating any in-field progression were considered LFs. Secondary outcomes of interest were post-SRS pain flare, vertebral compression fracture, instrumentation failure, and any Grade ≥ 3 toxicity. Cumulative incidences analysis was used to estimate LF in each cohort, which were compared via Gray's test. Multivariate competing-risks regression was then used to adjust for prespecified covariates. RESULTS Of 650 candidates for the control group, 166 were propensity matched to 83 patients with instrumentation. Baseline characteristics were well balanced. The median prescription dose was 16 Gy in each cohort. The 12-month cumulative incidence of LF was not statistically significantly different between cohorts (22.8% [instrumentation] vs 15.8% [control], p = 0.25). After adjusting for the prespecified covariates in a multivariate competing-risks model, decompression with instrumentation did not contribute to a greater risk of LF (HR 1.21, 95% CI 0.74-1.98, p

Laboratory and numerical decompression experiments: an insight into the nucleation and growth of bubbles

NASA Astrophysics Data System (ADS)

Spina, L.; Colucci, S.; De'Michieli Vitturi, M.; Scheu, B.; Dingwell, D. B.

2014-12-01

Numerical modeling, joined with experimental investigations, is fundamental for studying the dynamics of magmatic fluid into the conduit, where direct observations are unattainable. Furthermore, laboratory experiments can provide invaluable data to vunalidate complex multiphase codes. With the aim on unveil the essence of nucleation process, as well as the behavior of the multiphase magmatic fluid, we performed slow decompression experiments in a shock tube system. We choose silicon oil as analogue for the magmatic melt, and saturated it with Argon at 10 MPa for 72h. The slow decompression to atmospheric conditions was monitored through a high speed camera and pressure sensors, located into the experimental conduit. The experimental conditions of the decompression process have then been reproduced numerically with a compressible multiphase solver based on OpenFOAM. Numerical simulations have been performed by the OpenFOAM compressibleInterFoam solver for 2 compressible, non-isothermal immiscible fluids, using a VOF (volume of fluid) phase-fraction based interface capturing approach. The data extracted from 2D images obtained from laboratory analyses were compared to the outcome of numerical investigation, showing the capability of the model to capture the main processes studied.

Description of the NASA Hypobaric Decompression Sickness Database (1982-1998)

NASA Technical Reports Server (NTRS)

Wessel, J. H., III; Conkin, J.

2008-01-01

The availability of high-speed computers, data analysis software, and internet communication are compelling reasons to describe and make available computer databases from many disciplines. Methods: Human research using hypobaric chambers to understand and then prevent decompression sickness (DCS) during space walks has been conducted at the Johnson Space Center (JSC) from 1982 to 1998. The data are archived in the NASA Hypobaric Decompression Sickness Database, within an Access 2003 Relational Database. Results: There are 548 records from 237 individuals that participated in 31 unique tests. Each record includes physical characteristics, the denitrogenation procedure that was tested, and the outcome of the test, such as the report of a DCS symptom and the intensity of venous gas emboli (VGE) detected with an ultrasound Doppler bubble detector as they travel in the venous blood along the pulmonary artery on the way to the lungs. We documented 84 cases of DCS and 226 cases where VGE were detected. The test altitudes were 10.2, 10.1, 6.5, 6.0, and 4.3 pounds per square inch absolute (psia). 346 records are from tests conducted at 4.3 psia, the operating pressure of the current U.S. space suit. 169 records evaluate the Staged 10.2 psia Decompression Protocol used by the Space Shuttle Program. The mean exposure time at altitude was 242.3 minutes (SD = 80.6), with a range from 120 to 360 minutes. Among our test subjects, 96 records of exposures are females. The mean age of all test subjects was 31.8 years (SD = 7.17), with a range from 20 to 54 years. Discussion: These data combined with other published databases and evaluated with metaanalysis techniques would extend our understanding about DCS. A better understanding about the cause and prevention of DCS would benefit astronauts, aviators, and divers.

Improved image decompression for reduced transform coding artifacts

NASA Technical Reports Server (NTRS)

Orourke, Thomas P.; Stevenson, Robert L.

1994-01-01

The perceived quality of images reconstructed from low bit rate compression is severely degraded by the appearance of transform coding artifacts. This paper proposes a method for producing higher quality reconstructed images based on a stochastic model for the image data. Quantization (scalar or vector) partitions the transform coefficient space and maps all points in a partition cell to a representative reconstruction point, usually taken as the centroid of the cell. The proposed image estimation technique selects the reconstruction point within the quantization partition cell which results in a reconstructed image which best fits a non-Gaussian Markov random field (MRF) image model. This approach results in a convex constrained optimization problem which can be solved iteratively. At each iteration, the gradient projection method is used to update the estimate based on the image model. In the transform domain, the resulting coefficient reconstruction points are projected to the particular quantization partition cells defined by the compressed image. Experimental results will be shown for images compressed using scalar quantization of block DCT and using vector quantization of subband wavelet transform. The proposed image decompression provides a reconstructed image with reduced visibility of transform coding artifacts and superior perceived quality.

Decompression sickness in a vegetarian diver: are vegetarian divers at risk? A case report.

PubMed

van Hulst, Robert A; van der Kamp, Wim

2010-01-01

We present a case of a diver who suffered decompression sickness (DCS), but who also was a strict vegetarian for more than 10 years. He presented with symptoms of tingling of both feet and left hand, weakness in both legs and sensory deficits for vibration and propriocepsis after two deep dives with decompression. The initial clinical features of this case were most consistent with DCS, possibly because of a vulnerable spinal cord due to cobalamin deficiency neuropathy. This case illustrates the similarities between DCS and a clinically defined vitamin B12 deficiency. The pathophysiology of vitamin B12 deficiency and common pathology and symptoms of DCS are reviewed.

A metastable liquid melted from a crystalline solid under decompression

DOE PAGES

Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; ...

2017-01-23

A metastable liquid may exist under supercooling, sustaining the liquid below the melting point such as supercooled water and silicon. It may also exist as a transient state in solid–solid transitions, as demonstrated in recent studies of colloidal particles and glass-forming metallic systems. One important question is whether a crystalline solid may directly melt into a sustainable metastable liquid. By thermal heating, a crystalline solid will always melt into a liquid above the melting point. Here we report that a high-pressure crystalline phase of bismuth can melt into a metastable liquid below the melting line through a decompression process. Themore » decompression-induced metastable liquid can be maintained for hours in static conditions, and transform to crystalline phases when external perturbations, such as heating and cooling, are applied. It occurs in the pressure–temperature region similar to where the supercooled liquid Bi is observed. Finally, akin to supercooled liquid, the pressure-induced metastable liquid may be more ubiquitous than we thought.« less

Minimally invasive carpal tunnel decompression using the KnifeLight.

PubMed

Hwang, Peter Y K; Ho, Chi Long

2007-02-01

Carpal tunnel syndrome is a common condition causing hand pain, dysfunction, and paresthesia. Endoscopic carpal tunnel decompression offers many advantages compared with conventional open surgical decompression. However, it is equipment intensive and requires familiarity with endoscopic surgery. We review a minimally invasive technique to divide the flexor retinaculum by using a new instrument, the KnifeLight (Stryker, Kalamazoo, Michigan), which combines the advantages of the open and endoscopic methods, without the need for endoscopic set-up. Between July 2003 and April 2005, 44 consecutive patients (26 women [59%] and 18 men [36%]), with clinical signs and symptoms, as well as electrodiagnostic findings consistent with carpal tunnel syndrome, who did not respond to non-surgical treatment, underwent the new procedure. All patients were asked about scar hypertrophy, scar tenderness, and pillar pain. The Michigan Hand Outcomes Questionnaire (MHQ) was used to determine overall hand function, activities of daily living, work performance, pain, aesthetics, and satisfaction with hand function. Other preoperative testing included grip strength and lateral pinch strength. Grip strength was measured using the Jamar hand dynamometer (Asimov Engineering Co., Los Angeles, CA); lateral key pinch was measured using the Jamar hydraulic pinch gauge. Postoperative evaluations were scheduled at 2 weeks, 3 months, and 6 months after the procedure. A small 10-mm incision was made in the wrist crease and a small opening was made at the transverse carpal ligament. The KnifeLight tool was inserted, and the ligament was incised completely. Follow-up evaluations with use of quantitative measurements of grip strength, pinch strength, and hand dexterity were performed at 2 weeks, 3 months, and 6 months after surgery. Fifty procedures were performed on 22 left hands (44%) and 28 right hands (56%). There were no complications related to the approach. All patients were able to use their hands

Decompressive Hemicraniectomy in a South American Population – Morbidity and Outcomes Analysis

PubMed Central

Vital, Roberto Bezerra; Hamamoto Filho, Pedro Tadao; Luvizutto, Gustavo Jose; Ducati, Luis Gustavo; Braga, Gabriel Pereira; Nunes, Helio Rubens de Carvalho; Romero, Flavio Ramalho; Ganem, Eliana Marisa; Zanini, Marco Antonio; Bazan, Rodrigo

2016-01-01

Background Malignant cerebral artery strokes have a poor prognosis, with nearly 80% of mortality in some series despite intensive care. After a large randomized trial, decompressive hemicraniectomy has been performed more often in stroke patients. Here, we describe patients in a tertiary teaching hospital in Brazil, emphasizing the impact of age on outcomes. Methods A retrospective cohort of patients, with malignant strokes which received a decompressive hemicraniectomy, from paper and electronic medical records, from January 2010 to December 2013 was divided into two groups according to age. Results The final analysis included 60 patients. The overall mortality was higher among patients older than 60 yrs (67% vs. 41%; p = 0.039), whose group also had a worse outcome (76% with mRS 5 or 6) at 90 days (OR 3.91 CI95% 1.30–11.74), whereas only 24% had mRS of 0–4 (p = 0.015). All patients who presented with sepsis died (p = 0.003). The incidence of pulmonary infection was very high in the elderly group (76%) with significant intergroup differences (p = 0.027, OR 8.32 CI95% 0.70–98.48). Conclusions Older patients present more commonly with infections, more disabilities and a higher mortality, highlighting very poor results in elderly population. These results should be proved with a South American trial, and if confirmed, it can impact on future decisions regarding decompressive craniectomy for acute ischemic stroke in our region. PMID:26764485

Decompression Sickness During Simulated Low Pressure Exposure is Increased with Mild Ambulation Exercise

NASA Technical Reports Server (NTRS)

Pollock, N. W.; Natoli, M. J.; Martina, S. D.; Conkin, J.; Wessel, J. H., III; Gernhardt, M. L.

2016-01-01

Musculoskeletal activity accelerates inert gas elimination during oxygen breathing prior to decompression (prebreathe), but may also promote bubble formation (nucleation) and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of musculoskeletal activity are likely critical to the net effect. The NASA Prebreathe Reduction Program (PRP) combined oxygen prebreathe and exercise preceding a 4.3 psia exposure in non-ambulatory subjects (a microgravity analog) to produce two protocols now used by astronauts preparing for extravehicular activity - one employing cycling and non-cycling exercise (CEVIS: 'cycle ergometer vibration isolation system') and one relying on non-cycling exercise only (ISLE: 'in-suit light exercise'). Current efforts investigate whether light exercise normal to 1 G environments increases the risk of DCS over microgravity simulation.

Blood biochemical and cellular changes during decompression and simulated extravehicular activity

NASA Technical Reports Server (NTRS)

Jauchem, J. R.; Waligora, J. M.; Johnson, P. C. Jr

1990-01-01

Blood biochemical and cellular parameters were measured in human subjects before and after exposure to a decompression schedule involving 6 h of oxygen prebreathing. The exposure was designed to simulate extravehicular activity for 6 h (subjects performed exercise while exposed to 29.6 kPa). There were no significant differences between blood samples from subjects who were susceptible (n = 11) versus those who were resistant (n = 27) to formation of venous gas emboli. Although several statistically significant (P less than 0.05) changes in blood parameters were observed following the exposure (increases in white blood cell count, prothrombin time, and total bilirubin, and decreases in triglycerides, very-low-density lipoprotein cholesterol, and blood urea nitrogen), the changes were small in magnitude and blood factor levels remained within normal clinical ranges. Thus, the decompression schedule used in this study is not likely to result in blood changes that would pose a threat to astronauts during extravehicular activity.

Does minimal access tubular assisted spine surgery increase or decrease complications in spinal decompression or fusion?

PubMed

Fourney, Daryl R; Dettori, Joseph R; Norvell, Daniel C; Dekutoski, Mark B

2010-04-20

Systematic review. The purpose of this review was to attempt to answer the following 2 clinical questions: (1) Does minimal access tubular assisted spine surgery (MAS) decrease the rate of complications in posterior thoracolumbar decompression and/or fusion surgery compared with traditional open techniques? (2) What strategies to reduce the risk of complications in MAS have been shown to be effective? The objective of minimal access spine surgery is to reduce damage to surrounding tissues while accomplishing the same goals as conventional surgery. Patient demand and marketing for MAS is driven by the perception of better outcomes, although the purported advantages remain unproven. Whether the risk of complications is affected by minimal access techniques is unknown. A systematic review of the English language literature was undertaken for articles published between 1990 and July 2009. Electronic databases and reference lists of key articles were searched to identify published studies that compared the rate of complications after MAS to a control group that underwent open surgery. Single-arm studies were excluded. Two independent reviewers assessed the strength of literature using GRADE criteria assessing quality, quantity, and consistency of results. Disagreements were resolved by consensus. From the 361 articles identified, 13 met a priori criteria and were included for review. All of the studies evaluated only lumbar spine surgery. The single large randomized study showed less favorable results for MAS discectomy, but no significant difference in complication rates. The quality of the other studies, particularly for fusion surgery, was low. Overall, the rates of reoperation, dural tear, cerebrospinal fluid leak, nerve injury, and infection occurred in similar proportions between MAS and open surgery. Blood loss was reduced in MAS fusion; however, the quality of those studies was very low. Operation time and hospital length of stay was variable across studies

Decompression sickness ('the bends') in sea turtles.

PubMed

García-Párraga, D; Crespo-Picazo, J L; de Quirós, Y Bernaldo; Cervera, V; Martí-Bonmati, L; Díaz-Delgado, J; Arbelo, M; Moore, M J; Jepson, P D; Fernández, Antonio

2014-10-16

Decompression sickness (DCS), as clinically diagnosed by reversal of symptoms with recompression, has never been reported in aquatic breath-hold diving vertebrates despite the occurrence of tissue gas tensions sufficient for bubble formation and injury in terrestrial animals. Similarly to diving mammals, sea turtles manage gas exchange and decompression through anatomical, physiological, and behavioral adaptations. In the former group, DCS-like lesions have been observed on necropsies following behavioral disturbance such as high-powered acoustic sources (e.g. active sonar) and in bycaught animals. In sea turtles, in spite of abundant literature on diving physiology and bycatch interference, this is the first report of DCS-like symptoms and lesions. We diagnosed a clinico-pathological condition consistent with DCS in 29 gas-embolized loggerhead sea turtles Caretta caretta from a sample of 67. Fifty-nine were recovered alive and 8 had recently died following bycatch in trawls and gillnets of local fisheries from the east coast of Spain. Gas embolization and distribution in vital organs were evaluated through conventional radiography, computed tomography, and ultrasound. Additionally, positive response following repressurization was clinically observed in 2 live affected turtles. Gas embolism was also observed postmortem in carcasses and tissues as described in cetaceans and human divers. Compositional gas analysis of intravascular bubbles was consistent with DCS. Definitive diagnosis of DCS in sea turtles opens a new era for research in sea turtle diving physiology, conservation, and bycatch impact mitigation, as well as for comparative studies in other air-breathing marine vertebrates and human divers.

The effect of dynamic, semi-rigid implants on the range of motion of lumbar motion segments after decompression.

PubMed

Schulte, Tobias L; Hurschler, Christof; Haversath, Marcel; Liljenqvist, Ulf; Bullmann, Viola; Filler, Timm J; Osada, Nani; Fallenberg, Eva-Maria; Hackenberg, Lars

2008-08-01

Undercutting decompression is a common surgical procedure for the therapy of lumbar spinal canal stenosis. Segmental instability, due to segmental degeneration or iatrogenic decompression is a typical problem that is clinically addressed by fusion, or more recently by semi-rigid stabilization devices. The objective of this experimental biomechanical study was to investigate the influence of spinal decompression alone, as well as in conjunction with two semi-rigid stabilizing implants (Wallis, Dynesys) on the range of motion (ROM) of lumbar spine segments. A total of 21 fresh-frozen human lumbar spine motion segments were obtained. Range of motion and neutral zone (NZ) were measured in flexion-extension (FE), lateral bending (LAT) and axial rotation (ROT) for each motion segment under four conditions: (1) with all stabilizing structures intact (PHY), (2) after bilateral undercutting decompression (UDC), (3) after additional implantation of Wallis (UDC-W) and (4) after removal of Wallis and subsequent implantation of Dynesys (UDC-D). Measurements were performed using a sensor-guided industrial robot in a pure-moment-loading mode. Range of motion was defined as the angle covered between loadings of -5 and +5 Nm during the last of three applied motion cycles. Untreated physiologic segments showed the following mean ROM: FE 6.6 degrees , LAT 7.4 degrees , ROT 3.9 degrees . After decompression, a significant increase of ROM was observed: 26% FE, 6% LAT, 12% ROT. After additional implantation of a semi-rigid device, a decrease in ROM compared to the situation after decompression alone was observed with a reduction of 66 and 75% in FE, 6 and 70% in LAT, and 5 and 22% in ROT being observed for the Wallis and Dynesys, respectively. When the flexion and extension contribution to ROM was separated, the Wallis implant restricted extension by 69% and flexion by 62%, the Dynesys by 73 and 75%, respectively. Compared to the intact status, instrumentation following decompression

Intraocular pressure lowering effect of orbital decompression is related to increased venous outflow in Graves orbitopathy.

PubMed

Onaran, Zafer; Konuk, Onur; Oktar, Suna Özhan; Yücel, Cem; Unal, Mehmet

2014-07-01

To investigate the effects of combined orbital bone and fat decompression on intraocular pressure (IOP) and superior ophthalmic vein blood flow velocity (SOV-BFV), and their association with the clinical features of Graves orbitopathy (GO). During the 2002-2008 period, 72 eyes of 36 GO cases demonstrating moderate to severe orbitopathy were evaluated according to their clinical features as: cases with or without dysthyroid optic neuropathy (DON), and underwent orbital decompression. A control group comprised 40 eyes of 20 healthy subjects. In both groups, a full ophthalmic examination including IOP and Hertel measurements was performed, and SOV-BFV was analyzed with color Doppler imaging. Examinations were repeated after orbital decompression in GO patients. All the cases demonstrated clinical features of inactive disease. Among the patients 24 of 72 eyes (33.3%) showed clinical features of DON. After surgery, the mean decrease in Hertel values was 6.2 ± 1.8 mm (p = 0.001). The mean decrease in IOP was 3.0 ± 1.7 mmHg (from 17.3 ± 2.7 to 14.3 ± 2.0 mmHg) after orbital decompression where the post-operative values were comparable with the control group (12.9 ± 1.4 mmHg, p = 0.36). The mean increase in SOV-BFV achieved with decompression was 1.2 ± 0.6 cm/s (from 4.8 ± 1.7 to 6.0 ± 1.8 cm/s) and post-operative SOV-BFV values were also comparable with the control group (6.6 ± 1.3 cm/s, p = 0.26). The increase in SOV-BFV in cases with DON did not differ from cases without DON (p = 0.32), however, post-operative SOV-BFV of cases with DON was stil lower than cases without DON (p = 0.035). Combined orbital bone and fat decompression significantly reduced the IOP levels and increased the SOV-BFV in GO. This could be the confirmative finding of prediction that elevated IOP in GO is associated with increased episcleral venous pressure. The post-operative changes in IOP and SOV-BFV show differences

Differential Effects of Temperature Extremes on Hospital Admission Rates for Respiratory Disease between Indigenous and Non-Indigenous Australians in the Northern Territory

PubMed Central

Green, Donna; Bambrick, Hilary; Tait, Peter; Goldie, James; Schultz, Rosalie; Webb, Leanne; Alexander, Lisa; Pitman, Andrew

2015-01-01

The health gap between Indigenous and non-Indigenous Australians may be exacerbated by climate change if temperature extremes have disproportionate adverse effects on Indigenous people. To explore this issue, we analysed the effect of temperature extremes on hospital admissions for respiratory diseases, stratified by age, Indigenous status and sex, for people living in two different climates zones in the Northern Territory during the period 1993–2011. We examined admissions for both acute and chronic respiratory diagnoses, controlling for day of the week and seasonality variables. Our analysis showed that: (1) overall, Indigenous hospital admission rates far exceeded non-Indigenous admission rates for acute and chronic diagnoses, and Top End climate zone admission rates exceeded Central Australia climate zone admission rates; (2) extreme cold and hot temperatures were associated with inconsistent changes in admission rates for acute respiratory disease in Indigenous and non-Indigenous children and older adults; and (3) no response to cold or hot temperature extremes was found for chronic respiratory diagnoses. These findings support our two hypotheses, that extreme hot and cold temperatures have a different effect on hospitalisations for respiratory disease between Indigenous and non-Indigenous people, and that these health risks vary between the different climate zones. We did not, however, find that there were differing responses to temperature extremes in the two populations, suggesting that any increased vulnerability to climate change in the Indigenous population of the Northern Territory arises from an increased underlying risk to respiratory disease and an already greater existing health burden. PMID:26633456

Gut fermentation seems to promote decompression sickness in humans.

PubMed

de Maistre, Sébastien; Vallee, Nicolas; Gempp, Emmanuel; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

2016-10-01

Massive bubble formation after diving can lead to decompression sickness (DCS) that can result in neurological disorders. In experimental dives using hydrogen as the diluent gas, decreasing the body's H 2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. In contrast, we have shown that gut bacterial fermentation in rats on a standard diet promotes DCS through endogenous hydrogen production. Therefore, we set out to test these experimental results in humans. Thirty-nine divers admitted into our hyperbaric center with neurological DCS (Affected Divers) were compared with 39 healthy divers (Unaffected Divers). Their last meal time and composition were recorded. Gut fermentation rate was estimated by measuring breath hydrogen 1-4 h after the dive. Breath hydrogen concentrations were significantly higher in Affected Divers (15 ppm [6-23] vs. 7 ppm [3-12]; P = 0.0078). With the use of a threshold value of 16.5 ppm, specificity was 87% [95% confidence interval (CI) 73-95] for association with neurological DCS onset. We observed a strong association between hydrogen values above this threshold and an accident occurrence (odds ratio = 5.3, 95% CI 1.8-15.7, P = 0.0025). However, high fermentation potential foodstuffs consumption was not different between Affected and Unaffected Divers. Gut fermentation rate at dive time seemed to be higher in Affected Divers. Hydrogen generated by fermentation diffuses throughout the body and could increase DCS risk. Prevention could be helped by excluding divers who are showing a high fermentation rate, by eliminating gas produced in gut, or even by modifying intestinal microbiota to reduce fermentation rate during a dive. Copyright © 2016 the American Physiological Society.

[Treatment of thoracolumbar burst fracture with lateral anterior decompression, internal fixation with Ventrofix and bone graft with titanic mesh].

PubMed

Zhang, Shi-min; Zhang, Zhao-jie; Liu, Yu-zhang; Zhang, Lu-tang; Li, Xing

2011-11-01

To discuss the efficacy of lateral anterior decompression, internal fixation with Ventrofix and bone graft with titanic mesh in the treatment of severe thoracolumbar burst fracture. From January 2008 to January 2010, 21 patients with severe thoracolumbar burst fracture were treated with lateral anterior decompression, internal fixation with Ventrofix, bone graft with titanic mesh. There were 15 males and 6 females, ranging in age from 21 to 46 years with an average of 32.2 years. Segment of fracture: 3 cases were in T11, 6 cases in T12, 7 cases in L1, 5 cases in L2. The mean kyphosis angle was 20.1 degrees and loading of fracture was 7.8 scores. Twenty-one cases accompany with incomplete paralysis. Nerves functions were observed according to Frankel grade; correction and maintain of kyphosis angle were observed by X-rays and CT. All the patients were followed up from 12 to 34 months with an average of 18.5 years. Postoperative complication including injury of pleura in 1 case, dynamic ileus in 2 cases, ilioinguinal nerve injury in 1 case, faulty union of wound in 1 case. All the above complications got recovery after symptomatic treatment. The mean kyphosis angle in fusional segment were 4.2 degrees and the rate of correction was 79%. Nerves functions of all patients got improvement and no internal fixation fail, kyphosis angle obviously lost, titanium mesh shifting, loosening and breakage of screw were found at final follow-up. Lateral anterior decompression, bone graft with titanic mesh, internal fixation with Ventrofix is an idea technique for severe thoracolumber burst fracture, but the method can not be used for patient with severity osteoporosis.

Transesophageal Echocardiographic Study of Decompression-Induced Venous Gas Emboli

NASA Technical Reports Server (NTRS)

Butler, B. D.; Morris, W. P.

1995-01-01

Transesophageal echo-cardiography was used to evaluate venous bubbles produced in nine anesthetized dogs following decompression from 2.84 bar after 120 min at pressure. In five dogs a pulsed Doppler cuff probe was placed around the inferior vena cava for bubble grade determination. The transesophageal echo images demonstrated several novel or less defined events. In each case where the pulmonary artery was clearly visualized, the venous bubbles were seen to oscillate back and forth several times, bringing into question the effect of coincidental counting in routine bubble grade analysis using precordial Doppler. A second finding was that in all cases, extensive bubbling occurred in the portal veins with complete extraction by the liver sinusoids, with one exception where a portal-to-hepatic venous anastomosis was observed. Compression of the bowel released copious numbers of bubbles into the portal veins, sometimes more than were released into the inferior vena cava. Finally, large masses of foam were routinely observed in the non-dependent regions of the inferior vena cava that not only delayed the appearance of bubbles in the pulmonary artery but also allowed additional opportunity for further reaction with blood products and for coalescence to occur before reaching the pulmonary microcirculation. These novel observations are discussed in relation to the decompression process.

The responsiveness of sensibility and strength tests in patients undergoing carpal tunnel decompression

PubMed Central

2011-01-01

Background Several clinical measures of sensory and motor function are used alongside patient-rated questionnaires to assess outcomes of carpal tunnel decompression. However there is a lack of evidence regarding which clinical tests are most responsive to clinically important change over time. Methods In a prospective cohort study 63 patients undergoing carpal tunnel decompression were assessed using standardised clinician-derived and patient reported outcomes before surgery, at 4 and 8 months follow up. Clinical sensory assessments included: touch threshold with monofilaments (WEST), shape-texture identification (STI™ test), static two-point discrimination (Mackinnon-Dellon Disk-Criminator) and the locognosia test. Motor assessments included: grip and tripod pinch strength using a digital grip analyser (MIE), manual muscle testing of abductor pollicis brevis and opponens pollicis using the Rotterdam Intrinsic Handheld Myometer (RIHM). The Boston Carpal Tunnel Questionnaire (BCTQ) was used as a patient rated outcome measure. Results Relative responsiveness at 4 months was highest for the BCTQ symptom severity scale with moderate to large effects sizes (ES = -1.43) followed by the BCTQ function scale (ES = -0.71). The WEST and STI™ were the most responsive sensory tests at 4 months showing moderate effect sizes (WEST ES = 0.55, STI ES = 0.52). Grip and pinch strength had a relatively higher responsiveness compared to thenar muscle strength but effect sizes for all motor tests were very small (ES ≤0.10) or negative indicating a decline compared to baseline in some patients. Conclusions For clinical assessment of sensibility touch threshold assessed by monofilaments (WEST) and tactile gnosis measured with the STI™ test are the most responsive tests and are recommended for future studies. The use of handheld myometry (RIHM) for manual muscle testing, despite more specifically targeting thenar muscles, was less responsive than grip or tripod pinch testing using

Investigation of Hematologic and Pathologic Response to Decompression.

DTIC Science & Technology

1978-05-10

in tadpole and very young kangaroos . Am. J. Physiol. 120:59—74 , 1937. 12. D’ C’~~~’ B.G. and Swanson , H. Bubble free decompression of blood samples...1955. 24. Takeda , Y. Studies of the metabol i~~ 5 and distribution of fibrino— gen in healthy men with autologous I-labe led fibrinogen. J. Clin...this connective tissue protein. However , the metabolism of bone collagen is affected by hormonal control (l0; 3l) and vitamin influences (3 ;ll). It

Complications and outcomes of grafting of posterior orbital fat into the lower lid-cheek junction during orbital decompression.

PubMed

Litwin, Andre S; Poitelea, Cornelia; Tan, Petrina; Ziahosseini, Kimia; Malhotra, Raman

2018-04-01

To report the complications of grafting of excised posterior orbital fat into the lower lid-cheek junction at the time of orbital decompression surgery. Retrospective review of consecutive patients undergoing orbital decompression combined with grafting of posterior orbital fat to the pre-malar and lateral canthal area (FG). A second group of consecutive patients undergoing orbital decompression but no orbital fat grafting (NoFG) were also studied as a form of comparative control. Standard patient data, including age, sex, visual acuity, degree of proptosis, operative details, diplopia or any other complications was collected. Independent assessment of pre- and post-operative photographs graded the lower lid-cheek junction. Thirty-four orbits of 29 patients, of which 21 orbits underwent orbital decompression with orbital fat grafting (FG). There were no intraoperative complications, postoperative infections, or visual loss. Complications relating to fat grafting included prolonged swelling in 3 (17%) patients at 3 months, in 1 case lasting 6 months, lower lid lumps in 3 (17%), and fat seepage in 1 (6%). The FG group achieved a greater improvement in the appearance of the lower-lid-cheek junction at 12 months in comparison to NoFG. Mean grade improvement 1.24 ± 1.09 vs 0 ± 0.82 (p = 0.025). Median follow-up was 20 months (range 6-30 months). Grafting of excised orbital fat during orbital decompression can improve the appearance of the lower lid-cheek junction in patients being treated for thyroid orbitopathy. However, 24% of patients will experience swelling and/or lumpiness requiring several months to settle or further fat excision.

Decompression Induced Crystallization of Basaltic Andesite Magma: Constraints on the Eruption of Arenal Volcano, Costa Rica.

NASA Astrophysics Data System (ADS)

Szramek, L. A.; Gardner, J. E.; Larsen, J. F.

2004-12-01

Arenal Volcano is a small stratovolcano located 90 km NW of San Jose, Costa Rica. In 1968 current activity began with a Plinian phase, and has continued to erupt lava flows and pyroclastic flows intermittently since. Samples from the Plinian, pyroclastic flow, strombolian, and effusive phases have been studied texturally. Little variation in crystallinity occurs amongst the different phases. Number density of crystals, both 2D and 3D are 50-70 mm-2 and 30,000-50,000 mm-3 in the Plinian sample, compared to the lesser values in other eruptive types. Characteristic crystal size also increases as explosivity decreases. Two samples, both lava flows collected while warm, overlap with the Plinian sample. This suggests that the variations seen may be a result of cooling history. Plagioclase differs between the Plinian sample, in which they are only tabular in shape, and the other eruptive types, which contain both tabular and equant crystals. To link decompression paths of the Arenal magma to possible pre-eruptive conditions, we have carried out hydrothermal experiments. The experiments were preformed in TZM pressure vessels buffered at a fugacity of Ni-NiO and water saturation. Phase equilibria results in conjunction with mineral compositions and temperature estimates by previous workers from active lava flows and two-pyroxene geothermometry, constrain the likely pre-eruptive conditions for the Arenal magma to 950-1040° C with a water pressure of 50-80 MPa. Samples that started from conditions that bracket our estimated pre-eruptive conditions were decompressed in steps of 5-30 MPa and held for various times at each step until 20 MPa was reached, approximating average decompression rates of 0.25, 0.025, 0.0013 MPa/s. Comparison of textures found in the natural samples to the experimentally produced textures suggest that the Plinian eruption likely was fed by magma ascending at 0.05-1 m/s, whereas the less explosive phases were fed by magma ascending at 0.05 m/s or less.

Early Outcomes of Endoscopic Contralateral Foraminal and Lateral Recess Decompression via an Interlaminar Approach in Patients with Unilateral Radiculopathy from Unilateral Foraminal Stenosis.

PubMed

Kim, Hyeun Sung; Patel, Ravish; Paudel, Byapak; Jang, Jee-Soo; Jang, Il-Tae; Oh, Seong-Hoon; Park, Jae Eun; Lee, Sol

2017-12-01

Percutaneous endoscopic contralateral interlaminar lumbar foraminotomy (PECILF) for lumbar degenerative spinal stenosis is an established procedure. Better preservation of contralateral facet joint compared with that of the approach side has been shown with uniportal bilateral decompression. The aim of this retrospective case series was to analyze the early clinical and radiologic outcomes of stand-alone contralateral foraminotomy and lateral recess decompression using PECILF. Twenty-six consecutive patients with unilateral lower limb radiculopathy underwent contralateral foraminotomy and lateral recess decompression using PECILF. Their clinical outcomes were evaluated with visual analog scale leg pain score, Oswestry Disability Index, and the MacNab criteria. Completeness of decompression was documented with a postoperative magnetic resonance imaging. Mean age for the study group was 62.9 ± 9.2 years and the male/female ratio was 4:9. A total of 30 levels were decompressed, with 18 patients (60%) undergoing decompression at L4-L5, 9 at L5-S1 (30%), 2 at L3-L4 (6.7%), and 1 at L2-L3 (3.3%). Mean estimated blood loss was 27 ± 15 mL per level. Mean operative duration was 48 ± 12 minutes/level. Visual analog scale leg score improved from 7.7 ± 1 to 1.8 ± 0.8 (P < 0.0001). Oswestry Disability Index improved from 64.4 ± 5.8 to 21 ± 4.5 (P < 0.0001). Mean follow-up of the study was 13.7 ± 2.7 months. According to the MacNab criteria, 10 patients (38.5%) had good results, 14 patients (53.8%) had excellent results, and 2 patients (7.7%) had fair results. One patient required revision surgery. Facet-preserving contralateral foraminotomy and lateral recess decompression with PECILF is effective for treatment of lateral recess and foraminal stenosis. Thorough decompression with acceptable early clinical outcomes and minimal perioperative morbidity can be obtained with the contralateral endoscopic approach. Copyright © 2017 Elsevier Inc. All rights reserved.

Microstructures Developed During Natural and Experimental Decompression of Peridotite From Pressures of 10-15 GPa

NASA Astrophysics Data System (ADS)

Green, H. W.; Dobrzhinetskaya, L. F.

2004-12-01

Evidence is now robust that continental rocks and sediments can be subducted to P > 6 GPa during continental collision and returned to the surface. Moreover, mantle rocks exhumed with this subducted material carry evidence of P > 9 GPa and perhaps much more. We present a short review of natural examples and discuss them in the context of decompression experiments conducted on garnet lherzolite over the range 14 -> 5 GPa. Experiments at 14 GPa dissolved all enstatite (En) and about 85% diopside (Di) into garnet, yielding run products of 40% Ol + 55% Grt + 5% Di. Re-annealing this product at 13 or 12 GPa resulted in exsolution of Di as blebs at garnet grain boundaries and oriented platelets of Ol chemistry within grt. Specimens first equilibrated at 8 GPa dissolved abundant En but little Di. When re-annealed at 5 GPa, En exsolved as blebs at garnet boundaries -- very similar to interstitial blebs of enstatite along grt grain boundaries in UHP (>200 km) Norwegian grt-harzburgite. In the latter rocks, abundant En and rare Di exsolution lamellae are also found in the cores of large garnets. Our experiments do not show such lamellae, supporting the arguments of van Roermund and Drury (1998) that they are produced only in the cores of large grains and that the interstitial pyroxenes found in their specimens are also exsolution products. Ol has not been reported with exsolution morphology in natural UHP products, nor did we observe it in our experiments at P = 5 GPa. On the other hand, our observation that Ol may be exsolved during decompression of majoritic garnet during decompression at higher P is consistent with expansion of the garnet field at the expense of wadsleyite at P > 13 GPa reported by Ringwood (1991). Di, En, and/or Ol do occur along grain boundaries within larger polycrystalline garnets and within embayments at the margins of smaller amoeboid garnets in subduction zone garnet peridotites. Such garnets also may contain rounded, non-oriented, inclusions of

Microvascular decompression or neuromodulation in patients with SUNCT and trigeminal neurovascular conflict?

PubMed

Hassan, Samih; Lagrata, Susie; Levy, Andrew; Matharu, Manjit; Zrinzo, Ludvic

2018-02-01

Objectives To assess the effectiveness of neuromodulation and trigeminal microvascular decompression (MVD) in patients with medically-intractable short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT). Methods Two patients with medically refractory SUNCT underwent MVD following beneficial but incomplete response to neuromodulation (occipital nerve stimulation and deep brain stimulation). MRI confirmed neurovascular conflict with the ipsilateral trigeminal nerve in both patients. Results Although neuromodulation provided significant benefit, it did not deliver complete relief from pain and management required numerous postoperative visits with adjustment of medication and stimulation parameters. Conversely, MVD was successful in eliminating symptoms of SUNCT in both patients with no need for further medical treatment or neuromodulation. Conclusion Neuromodulation requires expensive hardware and lifelong follow-up and maintenance. These case reports highlight that microvascular decompression may be preferable to neuromodulation in the subset of SUNCT patients with ipsilateral neurovascular conflict.

Percutaneous intramedullary decompression, curettage, and grafting with medical-grade calcium sulfate pellets for unicameral bone cysts in children: a new minimally invasive technique.

PubMed

Dormans, John P; Sankar, Wudbhav N; Moroz, Leslie; Erol, Bülent

2005-01-01

Several treatment options exist for unicameral bone cysts (UBCs), including observation, steroid injection, bone marrow injection, and curettage and bone grafting. These are all associated with high recurrence rates, persistence, and occasional complications. Newer techniques have been described, most with variable success and only short follow-up reported. Because of these factors, a new minimally invasive percutaneous technique was developed for the treatment of UBCs in children. Twenty-eight children with UBCs who underwent percutaneous intramedullary decompression, curettage, and grafting with medical-grade calcium sulfate (MGCS) pellets by the senior author (J.P.D.) between April 2000 and April 2003 were analyzed as part of a pediatric musculoskeletal tumor registry at a large tertiary children's hospital. Four patients were lost to follow-up, and the remaining 24 patients had an average follow-up of 21.9 months (range 4-48 months). Twelve patients were followed for at least 24 months. Six of the 24 children had received previous treatment of their UBC, most often at an outside institution. Follow-up was performed through clinical evaluation and radiographic review. Postoperative radiographs at most recent follow-up showed complete healing, defined as more than 95% opacification, in 22 of 24 patients (91.7%). One patient (4.2%) demonstrated partial healing, defined as 80% to 95% opacification. One patient had less than 80% radiographic healing (4.2%). All 24 patients returned to full activities and were asymptomatic at most recent follow-up. The only complication noted was a superficial suture abscess that occurred in one patient; this resolved with local treatment measures. The new minimally invasive technique of percutaneous intramedullary decompression, curettage, and grafting with MGCS pellets demonstrates favorable results with low complication and recurrence rates compared with conventional techniques. The role of intramedullary decompression as a part

Blood biochemical and cellular changes during a decompression procedure involving eight hours of oxygen prebreathing

NASA Technical Reports Server (NTRS)

Jauchem, J. R.

1989-01-01

Chemical and cellular parameters were measured in human subjects before and after exposure to a decompression schedule involving 8 h of oxygen prebreathing. The exposure was designed to simulate space-flight extravehicular activity (EVA) for 6 h. Several statistically significant changes in blood parameters were observed following the exposure: increases in calcium, magnesium, osmolality, low-density lipoprotein cholesterol, monocytes, and prothrombin time, and decreases in chloride, creatine phosphokinase and eosinophils. The changes, however, were small in magnitude and blood factor levels remained within normal clinical ranges. Thus, the decompression profile used in this study is not likely to result in blood changes that would pose a threat to astronauts during EVA.

Threshold altitude resulting in decompression sickness

NASA Technical Reports Server (NTRS)

Kumar, K. V.; Waligora, James M.; Calkins, Dick S.

1990-01-01

A review of case reports, hypobaric chamber training data, and experimental evidence indicated that the threshold for incidence of altitude decompression sickness (DCS) was influenced by various factors such as prior denitrogenation, exercise or rest, and period of exposure, in addition to individual susceptibility. Fitting these data with appropriate statistical models makes it possible to examine the influence of various factors on the threshold for DCS. This approach was illustrated by logistic regression analysis on the incidence of DCS below 9144 m. Estimations using these regressions showed that, under a noprebreathe, 6-h exposure, simulated EVA profile, the threshold for symptoms occurred at approximately 3353 m; while under a noprebreathe, 2-h exposure profile with knee-bends exercise, the threshold occurred at 7925 m.

Comparison of posterior fossa decompression with and without duraplasty for the surgical treatment of Chiari malformation type I in adult patients

PubMed Central

Chen, Junchen; Li, Yongning; Wang, Tianyu; Gao, Jun; Xu, Jincheng; Lai, Runlong; Tan, Dianhui

2017-01-01

Abstract Chiari malformation type I (CM-I) is a congenital neurosurgical disease about the herniation of cerebellar tonsil through the foramen magnum. A variety of surgical techniques for CM-I have been used, and there is a controversy whether to use posterior fossa decompression with duraplasty (PFDD) or posterior fossa decompression without duraplasty (PFD) in CM-I patients. Here, we compared the clinical results and effectiveness of PFDD and PFD in adult patients with CM-I. The cases of 103 adult CM-I patients who underwent posterior fossa decompression with or without duraplasty from 2008 to 2014 were reviewed retrospectively. Patients were divided into 2 groups according to the surgical techniques: PFDD group (n = 70) and PFD group (n = 33). We compared the demographics, preoperative symptoms, radiographic characteristics, postoperative complications, and clinical outcomes between the PFD and PFDD patients. No statistically significant differences were found between the PFDD and PFD groups with regard to demographics, preoperative symptoms, radiographic characteristics, and clinical outcomes(P > 0.05); however, the postoperative complication aseptic meningitis occurred more frequently in the PFDD group than in the PFD group (P = 0.027). We also performed a literature review about the PFDD and PFD and made a summary of these preview studies. Our study suggests that both PFDD and PFD could achieve similar clinical outcomes for adult CM-I patients. The choice of surgical procedure should be based on the patient's condition. PFDD may lead to a higher complication rate and autologous grafts seemed to perform better than nonautologous grafts for duraplasty. PMID:28121938

Degassing of basaltic magma: decompression experiments and implications for interpreting the textures of volcanic rocks

NASA Astrophysics Data System (ADS)

Le Gall, Nolwenn; Pichavant, Michel; Cai, Biao; Lee, Peter; Burton, Mike

2017-04-01

Decompression experiments were performed to simulate the ascent of basaltic magma, with the idea of approaching the textural features of volcanic rocks to provide insights into degassing processes. The experiments were conducted in an internally heated pressure vessel between NNO-1.4 and +0.9. H2O-only (4.9 wt%) and H2O-CO2-bearing (0.71-2.45 wt% H2O, 818-1094 ppm CO2) melts, prepared from Stromboli pumice, were synthesized at 1200°C and 200 MPa, continuously decompressed between 200 and 25 MPa at a rate of either 39 or 78 kPa/s (or 1.5 and 3 m/s, respectively), and rapidly quenched. Run products were characterized both texturally (by X-ray computed tomography and scanning electron microscopy) and chemically (by IR spectroscopy and electron microprobe analysis), and then compared with products from basaltic Plinian eruptions and Stromboli paroxysms (bubble textures, glass inclusions). The obtained results demonstrate that textures are controlled by the kinetics of nucleation, growth, coalescence and outgassing of the bubbles, as well as by fragmentation, which largely depend on the presence of CO2 in the melt and the achievement in chemical equilibrium. Textures of the H2O-only melts result from two nucleation events, the first at high pressure (200 < P < 150 MPa) and the second at low pressure (50 < P < 25 MPa), preceding fragmentation. Both events, restricted to narrow P intervals, are driven by melt H2O supersaturation. In contrast, textures of the H2O-CO2-bearing basaltic melts result from continuous bubble nucleation, which is driven by the generation of melts supersaturated in CO2. This persistent non-equilibrium degassing causes the bubbles to evolve through power law distributions, as small bubbles continue to form and grow. This is what is observed in Plinian products. From our results, the evolution to mixed power law-exponential distributions, as found in Stromboli products, is indicative of the prevalence of bubble coalescence and an evolution toward

Macrovascular Decompression of the Brainstem and Cranial Nerves: Evolution of an Anteromedial Vertebrobasilar Artery Transposition Technique.

PubMed

Choudhri, Omar; Connolly, Ian D; Lawton, Michael T

2017-08-01

Tortuous and dolichoectatic vertebrobasilar arteries can impinge on the brainstem and cranial nerves to cause compression syndromes. Transposition techniques are often required to decompress the brainstem with dolichoectatic pathology. We describe our evolution of an anteromedial transposition technique and its efficacy in decompressing the brainstem and relieving symptoms. To present the anteromedial vertebrobasilar artery transposition technique for macrovascular decompression of the brainstem and cranial nerves. All patients who underwent vertebrobasilar artery transposition were identified from the prospectively maintained database of the Vascular Neurosurgery service, and their medical records were reviewed retrospectively. The extent of arterial displacement was measured pre- and postoperatively on imaging. Vertebrobasilar arterial transposition and macrovascular decompression was performed in 12 patients. Evolution in technique was characterized by gradual preference for the far-lateral approach, use of a sling technique with muslin wrap, and an anteromedial direction of pull on the vertebrobasilar artery with clip-assisted tethering to the clival dura. With this technique, mean lateral displacement decreased from 6.6 mm in the first half of the series to 3.8 mm in the last half of the series, and mean anterior displacement increased from 0.8 to 2.5 mm, with corresponding increases in satisfaction and relief of symptoms. Compressive dolichoectatic pathology directed laterally into cranial nerves and posteriorly into the brainstem can be corrected with anteromedial transposition towards the clivus. Our technique accomplishes this anteromedial transposition from an inferolateral surgical approach through the vagoaccessory triangle, with sling fixation to clival dura using aneurysm clips. Copyright © 2017 by the Congress of Neurological Surgeons

Operation Everest II. Altitude Decompression Sickness during Repeated Altitude Exposure,

DTIC Science & Technology

1986-05-01

Bends, Altitude, Hypobaric Chamber ILrJ " . .. . . " --" . .. " * .- . - - ’,, 3 INTRODUCTION Altitude Decompression Sickness (ADS) is a well...recognized and serious consequence of exposure to hypobaric conditions. It has been described during and after aircraft as well as hypobaric chamber flights...was noted in investigators during a recent study of chronic progressive hypoxia in a hypobaric chamber entitled Operation Everest II. The observations

Urinary retention: benefit of gradual bladder decompression - myth or truth? A randomized controlled trial.

PubMed

Boettcher, S; Brandt, A S; Roth, S; Mathers, M J; Lazica, D A

2013-01-01

Urinary retention is a common emergency requiring immediate catheterization. Gradual decompression (GD) of the extended bladder is believed to minimize the risk of complications such as bleeding or circulatory collapse, but to date it has not been compared with rapid decompression (RD) in controlled trials. Male patients presenting with urinary retention (n = 294) were randomized to rapid or gradual catheterization. For the latter, the transurethral catheter was clamped for 5 min after every 200-ml outflow until the bladder was completely empty. Patients were monitored for at least 30 min thereafter with regular checks of vital signs and presence of macroscopic hematuria. Of 294 patients, 142 (48.3%) were randomized to the GD and 152 (51.7%) to the RD group. Both groups showed no statistically significant difference with regard to age, anticoagulation treatment, catheter size and material, or volume retained. Hematuria occurred in 16 (11.3%) of the GD and 16 (10.5%) of the RD group; 6 patients in the former and 4 in the latter required further treatment. No circulatory collapse occurred. We noted a decrease in the previously raised blood pressure and heart rate in both groups, although without clinical significance. In this first randomized trial, no statistically significant difference was noted between gradual and rapid emptying of the bladder for urinary retention. Gradual emptying did not reduce the risk of hematuria or circulatory collapse. Therefore, there is no need to prefer gradual over rapid emptying, which is both easy and safe. © 2013 S. Karger AG, Basel.

[Effectiveness of multiple small-diameter drilling decompression combined with hip arthroscopy for early osteonecrosis of the femoral head].

PubMed

Li, Ji; Li, Zhongli; Su, Xiangzheng; Liu, Chunhui; Zhang, Hao; Wang, Ketao

2017-09-01

To evaluate the effectiveness of multiple small-diameter drilling decompression combined with hip arthroscopy for early oeteonecrosis of the femoral head (ONFH). Between March 2010 and December 2013, 91 patients with early ONFH were treated with the operation of multiple small-diameter drilling decompression combined with hip arthroscopy in 39 cases (53 hips, group A) or with drilling decompression alone in 52 cases (74 hips, group B). The patients in 2 groups had obvious hip pain and limited motion before operation. There was no significant difference in gender, age, etiology, effected side, stage of osteonecrosis, and preoperative Harris score between 2 groups ( P >0.05). All operations succeeded and all incisions healed by first intention. The operation time was significantly longer in group A [(73.3±10.6) minutes] than in group B [(41.5±7.2) minutes] ( t =8.726, P =0.000). Temporary of sciatic nerve apraxia after operation occurred in 2 patients of group A, and no complication occurred in other patients. Patients were followed up 24-52 months (mean, 39.3 months) in group A and 24-48 months (mean, 34.6 months) in group B. At last follow-up, the Harris scores were 83.34±8.76 in group A and 76.61±9.22 in group B, showing significant differences when compared between 2 groups ( t =-4.247, P =0.029) and when compared with preoperative values in 2 groups ( t =-10.327, P =0.001; t =-8.216, P =0.008). X-ray films showed that the collapse of the femoral head was observed in 6 hips (1 hip at stage Ⅰand 5 hips at stage Ⅱ) in group A, and in 16 hips (4 hips at stageⅠand 12 hips at stage Ⅱ) in group B; and hip arthroplasty was performed. The total effective rates were 88.68% (47/53) in group A and 78.38% (58/74) in group B, respectively; showing significant difference between 2 groups ( χ 2 =5.241, P =0.041). Multiple small-diameter drilling decompression combined with hip arthroscopy is effective in pain relief, improvement of hip function, slowing-down the

Experimental evidence of low-density liquid water upon rapid decompression

PubMed Central

Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Shen, Guoyin

2018-01-01

Water is an extraordinary liquid, having a number of anomalous properties which become strongly enhanced in the supercooled region. Due to rapid crystallization of supercooled water, there exists a region that has been experimentally inaccessible for studying deeply supercooled bulk water. Using a rapid decompression technique integrated with in situ X-ray diffraction, we show that a high-pressure ice phase transforms to a low-density noncrystalline (LDN) form upon rapid release of pressure at temperatures of 140–165 K. The LDN subsequently crystallizes into ice-Ic through a diffusion-controlled process. Together with the change in crystallization rate with temperature, the experimental evidence indicates that the LDN is a low-density liquid (LDL). The measured X-ray diffraction data show that the LDL is tetrahedrally coordinated with the tetrahedral network fully developed and clearly linked to low-density amorphous ices. On the other hand, there is a distinct difference in structure between the LDL and supercooled water or liquid water in terms of the tetrahedral order parameter. PMID:29440411

Management of Bleeding Duodenal Varices with Combined TIPS Decompression and Trans-TIPS Transvenous Obliteration Utilizing 3% Sodium Tetradecyl Sulfate Foam Sclerosis.

PubMed

Saad, Wael E; Lippert, Allison; Schwaner, Sandra; Al-Osaimi, Abdullah; Sabri, Saher; Saad, Nael

2014-01-01

Endoscopic experience in the management of duodenal varices (DVs) is limited and challenging given the anatomic constraints and limited experience. The endovascular management of DVs is not yet established and the controversy of whether to manage them by decompression with a transjugular intrahepatic portosystemic shunt (TIPS) or by transvenous obliteration is unresolved. In the literature, the 6-12 month rebleeding rate of DVs after TIPS is 21-37% and after transvenous obliteration is 13%. The purpose of the study is to evaluate the clinical outcome of combined TIPS decompression and transvenous obliteration/sclerosis. This is a retrospective study (case series) of two institutions, evaluating patients who underwent TIPS and/or transvenous obliteration/sclerosis for bleeding DVs (from January 2009 to June 2013). TIPS was performed according to a standard procedure using covered stents. Transvenous obliteration (variceal sclerosis) from the systemic and/or portal venous circulation was performed utilizing 3% sodium tetradecyl sulfate foam. Transvenous obliteration was commonly augmented with coils and/or vascular plugs. Technical (technical success of establishing TIPS and completely obliterating the DVs) and clinical outcomes (rebleeding rate and survival) were evaluated. Five patients with liver cirrhosis presenting with bleeding DVs were included in the study with all eventually (and coincidentally) receiving TIPS and transvenous obliteration. Two of the five patients underwent concomitant TIPS and transvenous obliteration in the same procedural setting. However, three patients underwent transvenous obliteration due to bleeding despite a patent TIPS that had been previously placed. The average time from TIPS placement to transvenous obliteration was 125 days (range: 3-324 days). After having both procedures, there was no rebleeding in the patients during a mean follow-up period of 22 months (6-50 months). Coils and/or metallic vascular plugs were used to augment

A new technique in reference based DNA sequence compression algorithm: Enabling partial decompression

NASA Astrophysics Data System (ADS)

Banerjee, Kakoli; Prasad, R. A.

2014-10-01

The whole gamut of Genetic data is ever increasing exponentially. The human genome in its base format occupies almost thirty terabyte of data and doubling its size every two and a half year. It is well-know that computational resources are limited. The most important resource which genetic data requires in its collection, storage and retrieval is its storage space. Storage is limited. Computational performance is also dependent on storage and execution time. Transmission capabilities are also directly dependent on the size of the data. Hence Data compression techniques become an issue of utmost importance when we confront with the task of handling such giganticdatabases like GenBank. Decompression is also an issue when such huge databases are being handled. This paper is intended not only to provide genetic data compression but also partially decompress the genetic sequences.

Treatment of sickle cell disease's hip necrosis by core decompression: a prospective case-control study.

PubMed

Mukisi-Mukaza, M; Manicom, O; Alexis, C; Bashoun, K; Donkerwolcke, M; Burny, F

2009-11-01

The young age of patients, total arthroplasties complications risks, and implant costs justify evaluation of the results of core decompression in the treatment of sickle-cell disease avascular necrosis of the femoral head (ONFH). In sickle-cell disease necrosis, core decompression offers good relief from pain and delays the use of total arthroplasty in comparison to a conservatively treated control group by a simple non-weight bearing protocol. From 1994 to 2008, among 215 drepanocytic adults, 42 patients (22 genotype SS, 20 genotype SC; 15 men, 27 women) presented symptomatic ONFH. We report the data from a prospective study of two patients' groups: a non-operated group (16 patients aged 36.5+/-6.5 years, 23 hips) and an operated group (26 patients aged 30.3+/-2.8 years, 42 hips). The results were considered on the basis of change in clinical status according to the numeric evaluation of pain scale, the functional score of Merle d'Aubigné-Postel (MAP), the radiological progression of lesions, and the time delay to total arthroplasty. Twenty-three hips were conservatively treated by discharge (a pair of canes). After a follow-up period of 13.4+/-0.5 years, no pain improvement was noted (p=0.76), and MAP score was unchanged (p=0.27). Out of 23 hips managed by discharge, 9 stage IV hips (degenerative arthritis, 39.1%) underwent arthroplasty after an average delay of 2.6+/-2.4 years. Forty-two hips were treated by core decompression. The duration of follow-up was 11.3+/-1.8 years. Postoperatively, pain reduction and MAP score improvement were significant in 39 out of 42 hips (93%, p<0.0001). Twenty-nine out of these 42 hips had a favorable evolution. Ten hips (23.8%) progressed to total arthroplasty, after a period of 7.4+/-2.7 years, longer than the one of the non-operated group (p=0.0007). By comparing the two groups (operated and non-operated), the benefit of core decompression appeared very significant (p<0.0001). In addition to allocating patients osteonecrosis

Evaluation of 8.0-cm needle at the fourth anterior axillary line for needle chest decompression of tension pneumothorax.

PubMed

Chang, Samuel J; Ross, Samuel Wade; Kiefer, David J; Anderson, William E; Rogers, Amelia T; Sing, Ronald F; Callaway, David W

2014-04-01

Five-centimeter needles at the second intercostal space midclavicular line (2MCL) have high failure rates for decompression of tension pneumothorax. This study evaluates 8-cm needles directed at the fourth intercostal space anterior axillary line (4AAL). Retrospective radiographic analysis of 100 consecutive trauma patients 18 years or older from January to September 2011. Measurements of chest wall thickness (CWT) and depth to vital structure (DVS) were obtained at 2MCL and 4AAL. 4AAL measurements were taken based on two angles: closest vital structure and perpendicular to the chest wall. Primary outcome measures were radiographic decompression (RD) (defined as CWT < 80 mm) and radiographic noninjury (RNI) (DVS > 80 mm) of 8-cm needles at 4AAL. Secondary outcome measures are effect of angle of entry on RNI at 4AAL, RD and RNI of 8-cm needles at 2MCL, and comparison of 5-cm needles with 8-cm needles at both locations. Eighty-four percent of the patients were male, with mean Injury Severity Score (ISS) of 17.7 (range, 1.0-66.0) and body mass index of 26.8 (16.5-48.4). Mean CWT at 4AAL ranged from 37.6 mm to 39.9 mm, significantly thinner than mean CWT at 2MCL (43.3-46.7 mm). Eight-centimeter needle RD was more than 96% at both 4AAL and 2MCL. Five-centimeter RD ranged from 66% to 81% at all sites. Mean DVS at 4AAL ranged from 91.8 mm to 128.0 mm. RNI at all sites was more than 91% except at left 4AAL, when taken to the closest vital structure (mean DVS, 91.8 mm), with 68% RNI. Perpendicular entry increased DVS to 109.4 mm and subsequent RNI to 91%. Five-centimeter RNI at all sites was more than 99%. CWT at 4AAL is significantly thinner than 2MCL. Based on radiographic measurements, 8-cm catheters have a higher chance of pleural decompression when compared with 5-cm catheters. Steeper angle of entry at 4AAL improves 8-cm noninjury rates to more than 91%. Therapeutic/care management study, level IV.

Tension pneumothorax secondary to automatic mechanical compression decompression device.

PubMed

Hutchings, A C; Darcy, K J; Cumberbatch, G L A

2009-02-01

The details are presented of the first published case of a tension pneumothorax induced by an automatic compression-decompression (ACD) device during cardiac arrest. An elderly patient collapsed with back pain and, on arrival of the crew, was in pulseless electrical activity (PEA) arrest. He was promptly intubated and correct placement of the endotracheal tube was confirmed by noting equal air entry bilaterally and the ACD device applied. On the way to the hospital he was noted to have absent breath sounds on the left without any change in the position of the endotracheal tube. Needle decompression of the left chest caused a hiss of air but the patient remained in PEA. Intercostal drain insertion in the emergency department released a large quantity of air from his left chest but without any change in his condition. Post-mortem examination revealed a ruptured abdominal aortic aneurysm as the cause of death. Multiple left rib fractures and a left lung laceration secondary to the use of the ACD device were also noted, although the pathologist felt that the tension pneumothorax had not contributed to the patient's death. It is recommended that a simple or tension pneumothorax should be considered when there is unilateral absence of breath sounds in addition to endobronchial intubation if an ACD device is being used.

Microsurgical Decompression of the Cochlear Nerve to Treat Disabling Tinnitus via an Endoscope-Assisted Retrosigmoid Approach: The Padua Experience.

PubMed

Di Stadio, Arianna; Colangeli, Roberta; Dipietro, Laura; Martini, Alessandro; Parrino, Daniela; Nardello, Ennio; D'Avella, Domenico; Zanoletti, Elisabetta

2018-05-01

The use of surgical cochlear nerve decompression is controversial. This study aimed at investigating the safety and validity of microsurgical decompression via an endoscope-assisted retrosigmoid approach to treat tinnitus in patients with neurovascular compression of the cochlear nerve. Three patients with disabling tinnitus resulting from a loop in the internal auditory canal were evaluated with magnetic resonance imaging and tests of pure tone auditory, tinnitus, and auditory brain response (ABR) to identify the features of the cochlear nerve involvement. We observed a loop with a caliber greater than 0.8 mm in all patients. Patients were treated via an endoscope-assisted retrosigmoid microsurgical decompression. After surgery, none of the patients reported short-term or long-term complications. After surgery, tinnitus resolved immediately in 2 patients, whereas in the other patient symptoms persisted although they improved; in all patients, hearing was preserved and ABR improved. Microsurgical decompression via endoscope-assisted retrosigmoid approach is a promising, safe, and valid procedure for treating tinnitus caused by cochlear nerve compression. This procedure should be considered in patients with disabling tinnitus who have altered ABR and a loop that has a caliber greater than 0.8 mm and is in contact with the cochlear nerve. Copyright © 2018 Elsevier Inc. All rights reserved.

Innovative application of Cox Flexion Distraction Decompression to the knee: a retrospective case series

PubMed Central

Albano, Luigi

2017-01-01

Objective The purpose of this study is to introduce the application of Cox flexion distraction decompression as an innovative approach to treating knee pain and osteoarthritis. Methods Six months of clinical files from one chiropractic practice were retrospectively screened for patients who had been treated for knee pain. Twenty-five patients met the criteria for inclusion. The treatment provided was Cox flexion distraction decompression. Pre-treatment and post-treatment visual analog pain scales (VAS) were used to measure the results. In total, eight patients presented with acute knee pain (less than three months’ duration) and 18 patients presented with chronic knee pain (greater than three months) including two patients with continued knee pain after prosthetic replacement surgery. Results For all 25 patients, a change was observed in the mean VAS scores from 7.7 to 1.8. The mean number of treatments was 5.3 over an average of 3.0 weeks. Acute patient mean VAS scores dropped from 8.1 to 1.1 within 4.8 treatments over 2.4 weeks. Chronic patient mean VAS scores dropped from 7.5 to 2.2 within 5.4 treatments over 3.3 weeks. No adverse events were reported. Conclusion This study showed clinical improvement in patients with knee pain who were managed with Cox flexion distraction decompression applied to the knee. PMID:28928498

Surgical management of temple-related problems following lateral wall rim-sparing orbital decompression for thyroid-related orbitopathy.

PubMed

Siah, We Fong; Patel, Bhupendra Ck; Malhotra, Raman

2016-08-01

To report a case series of patients with persistent temple-related problems following lateral wall rim-sparing (LWRS) orbital decompression for thyroid-related orbitopathy and to discuss their management. Retrospective review of medical records of patients referred to two oculoplastic centres (Corneoplastic Unit, Queen Victoria Hospital, East Grinstead, UK and Moran Eye Center, University of Utah, Salt Lake City, USA) for intervention to improve/alleviate temple-related problems. All patients were seeking treatment for their persistent, temple-related problems of minimum 3 years' duration post decompression. The main outcome measure was the resolution or improvement of temple-related problems. Eleven orbits of six patients (five females) with a median age of 57 years (range 23-65) were included in this study. Temple-related problems consisted of cosmetically bothersome temple hollowness (n=11; 100%), masticatory oscillopsia (n=8; 73%), temple tenderness (n=4; 36%), 'clicking' sensation (n=4; 36%) and gaze-evoked ocular pain (n=4; 36%). Nine orbits were also complicated by proptosis and exposure keratopathy. Preoperative imaging studies showed the absence of lateral wall in all 11 orbits and evidence of prolapsed lacrimal gland into the wall defect in four orbits. Intervention included the repair of the lateral wall defect with a sheet implant, orbital decompression involving fat, the medial wall or orbital floor and autologous fat transfer or synthetic filler for temple hollowness. Postoperatively, there was full resolution of masticatory oscillation, temple tenderness, 'clicking' sensation and gaze-evoked ocular pain, and an improvement in temple hollowness. Pre-existing diplopia in one patient resolved after surgery while two patients developed new-onset diplopia necessitating strabismus surgery. This is the first paper to show that persistent, troublesome temple-related problems following LWRS orbital decompression can be surgically corrected. Patients

Neurologic decompression sickness following cabin pressure fluctuations at high altitude.

PubMed

Auten, Jonathan D; Kuhne, Michael A; Walker, Harlan M; Porter, Henry O

2010-04-01

Decompression sickness (DCS) occurs in diving, altitude chamber exposures, and unpressurized or depressurized high-altitude flights. Because DCS takes many forms, in-flight cases may be misinterpreted as hypoxia, hyperventilation, or viral illness, with resulting failure to respond appropriately. In this case, a 28-yr-old male pilot of a single-seat, tactical aircraft experienced 12 rapid pressure fluctuations while flying at 43,000 ft above sea level. He had no symptoms and decided to complete the flight, which required an additional 2 h in the air. Approximately 1 h later he began to experience fatigue, lightheadedness, and confusion, which he interpreted as onset of a viral illness. However, symptoms progressed to visual, cognitive, motor, and sensory degradations and it was with some difficulty that he landed safely at his destination. Neurologic DCS was suspected on initial evaluation by flight line medical personnel because of the delayed onset and symptom progression. He was transferred to a local Emergency Department and noted to have altered mental status, asymmetric motor deficits, and non-dermatomal paresthesias of the upper and lower extremities. Approximately 3.5 h after the incident and 2.5 h after the onset of symptoms he began hyperbaric oxygen therapy. He received partial relief at 30 min of the Navy DiveTable 6 and full resolution at 90 min; there were no recurrent symptoms at a 1-yr follow-up. This case highlights the importance of early recognition of in-flight DCS symptoms and landing as soon as possible rather than as soon as practical in all likely scenarios.

Intradiscal pressure study of percutaneous disc decompression with nucleoplasty in human cadavers.

PubMed

Chen, Yung C; Lee, Sang-heon; Chen, Darwin

2003-04-01

Intradiscal pressure was measured after percutaneous disc decompression by nucleoplasty in human cadavers with different degrees of disc degeneration. To assess intradiscal pressure change after disc decompression, and to analyze the influence of degeneration on the intradiscal pressure change. Partial removal of the nucleus has been shown to decompress herniated discs, relieving pressure on nerve roots and, in some cases, offering relief from disc pain. Nucleoplasty, a new minimally invasive procedure using patented Coblation technology, combines coagulation and ablation for partial removal of the nucleus. Coblated channels remove the tissue volume and may decrease the disc pressure. Three fresh human cadaver spinal specimens (T8-L5; age, 54-84 years; mean age, 70.7 years) were used in this investigation. The intradiscal pressure was measured at three points: before treatment, after each channel was created, and after treatment using a 25-guage 6-inch needle connected to a Merit Medical Systems Intellisystem Inflation Monitor. The needles were calibrated initially to approximately 30 pounds per square inch. For the control, the change in disc pressure was recorded by the same procedure without using Coblation energy. To evaluate the effectiveness of nucleoplasty, disc pressure changes were compared between treatment with and without Coblation energy. Intradiscal pressure was markedly reduced in the younger, healthy disc cadaver. In the older, degenerative disc cadavers, the change in intradiscal pressure after nucleoplasty was very small. There was an inverse correlation between the degree of disc degeneration and the change in intradiscal pressure. Pressure reduction through nucleoplasty is highly dependent on the degree of spine degeneration. Nucleoplasty markedly reduced intradiscal pressure in nondegenerative discs, but had a negligible effect on highly degenerative discs.

Soccer-Specific Warm-Up and Lower Extremity Injury Rates in Collegiate Male Soccer Players

PubMed Central

Grooms, Dustin R.; Palmer, Thomas; Onate, James A.; Myer, Gregory D.; Grindstaff, Terry

2013-01-01

Context: A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population. Objective: To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players. Design: Cohort study. Setting: One American collegiate soccer team followed for 2 seasons. Patients or Other Participants: Forty-one male collegiate athletes aged 18–25 years. Intervention(s): The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer. Main Outcome Measure(s): Lower extremity injury risk and time lost to lower extremity injury. Results: The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01). Conclusions: This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer

Clinical outcomes of radiotherapy as initial local therapy for Graves' ophthalmopathy and predictors of the need for post-radiotherapy decompressive surgery.

PubMed

Prabhu, Roshan S; Liebman, Lang; Wojno, Ted; Hayek, Brent; Hall, William A; Crocker, Ian

2012-06-19

The optimal initial local treatment for patients with Graves' ophthalmopathy (GO) is not fully characterized. The purpose of this retrospective study is to describe the clinical outcomes of RT as initial local therapy for GO and define predictors of the need for post-RT salvage bony decompressive surgery. 91 patients with active GO and without prior surgery were treated with RT as initial local therapy between 01/1999 and 12/2010, with a median follow-up period of 18.3 months (range 3.7 - 142 months). RT dose was 24 Gy in 12 fractions. 44 patients (48.4%) had prior use of steroids, with 31 (34.1%) being on steroids at the initiation of RT. The most common presenting symptoms were diplopia (79%), proptosis (71%) and soft tissue signs (62%). 84 patients (92.3%) experienced stabilization or improvement of GO symptoms. 58 patients (64%) experienced improvement in their symptoms. 19 patients (20.9%) underwent salvage post-RT bony decompressive surgery. Smoking status and total symptom score at 4 months were independent predictors of post-RT bony decompression with odds ratios of 3.23 (95% CI 1.03 - 10.2) and 1.59 (95% CI 1.06 - 2.4), respectively. Persistent objective vision loss at 4 months post-RT was the most important symptom type in predicting salvage decompression. Chronic dry eye occurred in 9 patients (9.9%) and cataracts developed in 4 patients (4.4%). RT is effective and well tolerated as initial local therapy for active GO, with only 21% of patients requiring decompressive surgery post RT. Most patients experience stabilization or improvement of GO symptoms, but moderate to significant response occurs in the minority of patients. Smoking status and total symptom severity at 4 months, primarily persistent objective vision loss, are the primary determinants of the need for post-RT salvage bony decompression. Patients who smoke or present with predominantly vision loss symptoms should be advised as to their lower likelihood of symptomatic response to

Inner Ear Damage during Decompression from Deep Dives 1975-1982.

DTIC Science & Technology

1984-01-01

was controlled and delivered by a computer-based system (PDP 11/04 computer; Digital Equipment Corp.). During training and testing, the animals were...decompression sickness. Initial trials with control animals had shown that the monkeys could withstand the Table 6 treatment .thout showing visible...observed shortly after the dive (Fig. 3). In this regard, the amount of exudate is similar to that observed in control animals. Moreover, bone and/or

Prophylactic transanal decompression tube versus non-prophylactic transanal decompression tube for anastomotic leakage prevention in low anterior resection for rectal cancer: a meta-analysis.

PubMed

Yang, Yun; Shu, Ye; Su, Fangyu; Xia, Lin; Duan, Baofeng; Wu, Xiaoting

2017-04-01

Transanal decompression tube (TDT), an alternative intervention believed to have potential equivalent efficacy in reducing anastomotic leakage after rectal cancer surgery and lower complication rates compared to protective stoma, was sporadically applied in some medical centers during recent decade. The objective of this meta-analysis was to evaluate the effect of the TDT in preventing the anastomotic leakage after low anterior resection for rectal cancer. The studies comparing TDT and non-TDT in rectal cancer were researched up to March 22, 2016 without language preference, in databases of PubMed, Web of Science, Cochrane library, International Clinical Trials Registry Platform, and National Clinical Trials Registry. The rates of anastomotic leakage, bleeding, and re-operation were separately calculated and compared between TDT and non-TDT groups using RevMan 5.3. Funnel plots, and Egger's tests were used to evaluate the publication biases of the studies. Two prospective randomized controlled trial studies and five observational cohort studies with 833 participants in TDT group and 939 participants in non-TDT group were finally included in this meta-analysis. The results indicated that the TDT group had lower anastomotic leakage rate than non-TDT group with significant RR (RR 0.44; 95 % CI 0.29-0.66; P < 0.0001) and heterogeneity (I 2  = 33 %; P = 0.18). So did the re-operation rate, with RR (RR 0.16; 95 % CI 0.07-0.37; P < 0.0001) and heterogeneity among the studies (I 2  = 0 %; P = 0.80). There was no significant difference in anastomotic bleeding rates (RR 1.48; 95 % CI 0.79-2.77; P = 0.22) (I 2  = 58 %; P = 0.09). No publication bias was found by Egger's test (anastomotic leakage rate, Pr > |z| = 0.224; re-operation rate, Pr > |z| = 0.425). TDT might be an efficient and economic intervention in preventing anastomotic leakage after rectal cancer surgery.

Surgical decompression in endocrine orbitopathy. Visual evoked potential evaluation and effect on the optic nerve.

PubMed

Clauser, Luigi C; Tieghi, Riccardo; Galie', Manlio; Franco, Filippo; Carinci, Francesco

2012-10-01

Endocrine orbitopathy (EO) represents the most frequent and important extrathyroidal stigma of Graves disease. This chronic autoimmune condition involves the orbital contents, including extraocular muscles, periorbital connective-fatty tissue and lacrimal gland. The increase of fat tissue and the enlargement of extraocular muscles within the bony confines of the orbit leads to proptosis, and in the most severe cases optic neuropathy, caused by compression and stretching of the optic nerve. The congestion and the pressure of the enlarged muscles, constrict the nerve and can lead to reduced sight or loss of vision with the so called "orbital apex syndrome". Generally surgical treatment of EO, based on fat and/or orbital wall expansion, is possible and effective in improving exophthalmos and diplopia. Since there are limited reports focussing on optic neuropathy recovery after fat and/or orbital walls decompression the Authors decided to perform a retrospective analysis on a series of patients affected by EO. The study population was composed of 10 patients affected by EO and presenting to the Unit of Cranio Maxillofacial Surgery, Center for Craniofacial Deformities & Orbital Surgery St. Anna Hospital and University, Ferrara, Italy, for evaluation and treatment. A complete Visual Evoked Potentials (VEP) evaluation was performed. There were seven women and three men with a median age of 55 years. Optic nerve VEP amplitude and latency were recorded as normal or pathological. Abnormal results were scored as moderate, mild and severe. Differences in VEP pre and post-operatively were recorded as present or absent (i.e. VEP Delta). Pearson chi square test was applied. There were 20 operated orbits. The first VEP evaluation was performed 3.2 months before surgery and post-operative VEP control was done after a mean of 18.7 months. Fat decompression was performed in all cases and eight patients had also bony decompression. VEP amplitude and latency were affected in 10 and 15

Enhancement of KTP/532 laser disc decompression and arthroscopic microdiscectomy with a vital dye

NASA Astrophysics Data System (ADS)

Yeung, Anthony T.

1993-07-01

Currently, the clinical indications and results of arthroscopic microdiscectomy and laser disc decompression come close to, but do not exceed, the results of classic discectomy or microdiscectomy for the whole spectrum of surgical disc herniations. However, as minimally invasive techniques continue to evolve, results can be expected to equal or be potentially superior to conventional surgery. This exhibit demonstrates how the use of a vital dye can enhance standard arthroscopic microdiscectomy techniques and, when used in conjunction with KTP/532 laser disc decompression, allows for better arthroscopic visualization, documentation, and extraction of nucleus pulposus, ultimately expanding the current limiting criteria for minimally invasive techniques. When proper patient selection is combined with good clinical indications, the surgical results are rather dramatic, often achieving immediate relief of sciatica in the operating room.

Elimination of Subsidence with 26-mm-Wide Cages in Extreme Lateral Interbody Fusion.

PubMed

Lang, Gernot; Navarro-Ramirez, Rodrigo; Gandevia, Lena; Hussain, Ibrahim; Nakhla, Jonathan; Zubkov, Micaella; Härtl, Roger

2017-08-01

Extreme lateral interbody fusion (ELIF) has gained popularity as a minimally invasive technique for indirect decompression. However, graft subsidence potentially threatens long-term success of ELIF. This study evaluated whether 26-mm-wide cages can eliminate subsidence and subsequent loss of decompression in ELIF. Patients undergoing ELIF surgery using a 26-mm-wide cage were analyzed retrospectively. Patient demographics and perioperative data for radiographic and clinical outcomes were recorded. Radiographic parameters included regional sagittal lumbar lordosis and foraminal and disc height. Clinical parameters were evaluated using the Oswestry Disability Index and visual analog scale. Subsidence of 26-mm-wide cages was compared with previous outcomes of patients undergoing ELIF using 18-mm-wide and 22-mm-wide cages. There were 21 patients and 28 spinal segments analyzed. Radiographic outcome measures such as disc and foraminal height revealed significant improvement at follow-up compared with before surgery (P = 0.001). Postoperative to last follow-up cage subsidence translated into 0.34 mm ± 0.26 and -0.55 mm ± 0.64 in disc and foraminal height loss, respectively. Patients with 26-mm-wide cages experienced less subsidence by means of disc (26 mm vs. 18 mm and 22 mm, P ≤ 0.05) and foraminal height (26 mm vs. 18 mm, P = 0.005; 26 mm vs. 22 mm, P = 0.208) loss compared with patients receiving 18-mm-wide and 22-mm-wide cages. The 26-mm-wide cages almost eliminated cage subsidence in ELIF. Compared with 18-mm-wide and 22-mm-wide cages, 26-mm-wide cages significantly reduced cage subsidence in ELIF at midterm follow-up. A 26-mm-wide cage should be used in ELIF to achieve sustained indirect decompression. Copyright © 2017. Published by Elsevier Inc.

Arthroscopic Decompression of a Type III Subspine Impingement.

PubMed

Ilizaliturri, Víctor M; Arriaga Sánchez, Rubén; Suarez-Ahedo, Carlos

2016-12-01

Extra-articular hip impingement refers to a variety of hip disorders causing pain and limited function in young, non-arthritic patients. Recently, there has been an increased focus on analyzing the degree of anterior inferior iliac spine (AIIS) dysmorphism and its correlation with subspine impingement (SSI), defined as abutment between a prominent distal aspect of the AIIS and the anterior aspect of the femoral head-neck junction. Arthroscopic decompression of the AIIS is recognized as an effective treatment for SSI. However, there may be some inherent risks of performing this procedure arthroscopically that require further investigation.

Macrovascular Decompression of Facial Nerve With Anteromedial Transposition of a Dolichoectatic Vertebral Artery: 3-Dimensional Operative Video.

PubMed

Tabani, Halima; Yousef, Sonia; Burkhardt, Jan-Karl; Gandhi, Sirin; Benet, Arnau; Lawton, Michael T

2018-05-21

Most cranial nerve compression syndromes (ie, trigeminal neuralgia and hemifacial spasm) are caused by small arteries impinging on a nerve and are relieved by microvascular decompression. Rarely, cranial nerve compression syndromes can be caused by large artery impingement and can be relieved by macrovascular decompression. When present, this compression often occurs in association with degenerative atherosclerosis in the vertebral arteries (VA) and basilar artery. Conservative treatment is recommended for mild forms, but surgical transposition of the VA away from the root entry zone (REZ) can be considered. This video demonstrates macrovascular decompression of a dolichoectatic VA in a 74-yr-old female with refractory left hemifacial spasm. After obtaining IRB approval, patient consent was sought for the procedure. With the patient in three-quarter-prone position, a far-lateral craniotomy was performed. The dentate ligament was cut to free the VA, and the suprahypoglossal portion of the vagoaccessory triangle was widened. VA compressed the REZ of the facial nerve, but was mobilized anteromedially off the REZ. A muslin sling was wrapped around the VA and its tail brought down to the clival dura, which was punctured with a 19-gauge needle and enlarged with a dissector. The sling was pulled anteromedially to this puncture site and secured to the dura with an aneurysm clip, relieving the REZ of all compression. The patient tolerated the procedure with mild, transient hoarseness and her hemifacial spasm resolved completely. This case demonstrates the macrovascular decompression technique with anteromedial transposition of the vertebrobasilar artery, which can also be used for trigeminal neuralgia.

Craniectomy-associated Progressive Extra-Axial Collections with Treated Hydrocephalus (CAPECTH): redefining a common complication of decompressive craniectomy.

PubMed

Nalbach, Stephen V; Ropper, Alexander E; Dunn, Ian F; Gormley, William B

2012-09-01

Extra-axial fluid collections following decompressive craniectomy have been observed in a variety of patient populations. These collections have traditionally been thought to represent extra-axial signs of hydrocephalus, but they often occur even in settings where hydrocephalus has been optimally treated. This study aims to elucidate the phenomenon of extra-axial fluid collections after decompressive craniectomy in patients with treated hydrocephalus, in order to improve identification, classification, prevention and treatment. We retrospectively reviewed all patients at a single institution undergoing decompressive craniectomy for refractory intracranial pressure elevations from June 2007 through December 2009. We identified 39 patients by reviewing clinical reports and imaging. Any patient who died on or prior to the third post-operative day (POD) was excluded. The analysis focused on patients with extra-axial collections and treated hydrocephalus. Twenty-one of 34 (62%) patients developed extra-axial collections and 18 of these developed collections despite ventricular drainage. Subgroup analysis revealed that seven of seven patients (100%) with subarachnoid hemorrhage, and 11 of 14 (79%) with traumatic brain injury developed collections. Extra-axial collections may develop after decompressive craniectomy despite aggressive treatment of communicating hydrocephalus. In these patients, the term "external hydrocephalus" does not appropriately capture the relevant pathophysiology. Instead, we define a new phenomenon, "Craniectomy-associated Progressive Extra-Axial Collections with Treated Hydrocephalus" (CAPECTH), as progressive collections despite aggressive cerebral spinal fluid (CSF) drainage. Our data indicate that early cranioplasty can help prevent the formation and worsening of this condition, presumably by returning normal CSF dynamics. Copyright © 2012 Elsevier Ltd. All rights reserved.

How fast pain, numbness, and paresthesia resolves after lumbar nerve root decompression: a retrospective study of patient's self-reported computerized pain drawing.

PubMed

Huang, Peng; Sengupta, Dilip K

2014-04-15

A single-center retrospective study. To compare the speed of recovery of different sensory symptoms, pain, numbness, and paresthesia, after lumbar nerve root decompression. Lumbar radiculopathy is characterized by different sensory symptoms like pain, numbness, and paresthesia, which may resolve at different rates after surgical decompression. Eighty-five cases with predominant lumbar radiculopathy treated surgically were reviewed. Oswestry Disability Index score, 36-Item Short Form Health Survey scores (Physical Component Summary and Mental Component Summary), and pain drawing at preoperative and at 6 weeks, 3 months, 6 months, and 1-year follow-up were reviewed. Recovery rate between different sensory symptoms were compared in all patients, and between the short-term compression (<6 mo) and long-term compression groups. At baseline, 73 (85.8%) patients had pain, 63 (74.1%) had numbness, and 38 (44.7%) had paresthesia; 28 (32.9%) had all these 3 component of sensory symptoms. Mean pain score improved fastest (55.3% at 6 wk); further resolution until 1 year was slow and not significant compared with each previous visit. Both numbness and paresthesia scores showed a trend of faster recovery during the initial 6-week period (20.5% and 24%, respectively); paresthesia recovery reached a plateau at 3 months postoperatively, but numbness continued a slow recovery until 1-year follow-up. Both Oswestry Disability Index score and Physical Component Summary scores (54.02 ± 1.87 and 26.29 ± 0.93, respectively, at baseline) improved significantly compared with each previous visits at 6 weeks and 3 months postoperatively, but further improvement was insignificant. Mental Component Summary showed a similar trend but smaller improvement. The short-term compression group had faster recovery of pain than the long-term compression group. In lumbar radiculopathy patients after surgical decompression, pain recovers fastest, in the first 6 weeks postoperatively, followed by

NanoSIMS results from olivine-hosted melt embayments: Magma ascent rate during explosive basaltic eruptions

NASA Astrophysics Data System (ADS)

Lloyd, Alexander S.; Ruprecht, Philipp; Hauri, Erik H.; Rose, William; Gonnermann, Helge M.; Plank, Terry

2014-08-01

The explosivity of volcanic eruptions is governed in part by the rate at which magma ascends and degasses. Because the time scales of eruptive processes can be exceptionally fast relative to standard geochronometers, magma ascent rate remains difficult to quantify. Here we use as a chronometer concentration gradients of volatile species along open melt embayments within olivine crystals. Continuous degassing of the external melt during magma ascent results in diffusion of volatile species from embayment interiors to the bubble located at their outlets. The novel aspect of this study is the measurement of concentration gradients in five volatile elements (CO2, H2O, S, Cl, F) at fine-scale (5-10 μm) using the NanoSIMS. The wide range in diffusivity and solubility of these different volatiles provides multiple constraints on ascent timescales over a range of depths. We focus on four 100-200 μm, olivine-hosted embayments erupted on October 17, 1974 during the sub-Plinian eruption of Volcán de Fuego. H2O, CO2, and S all decrease toward the embayment outlet bubble, while F and Cl increase or remain roughly constant. Compared to an extensive melt inclusion suite from the same day of the eruption, the embayments have lost both H2O and CO2 throughout the entire length of the embayment. We fit the profiles with a 1-D numerical diffusion model that allows varying diffusivities and external melt concentrations as a function of pressure. Assuming a constant decompression rate from the magma storage region at approximately 220 MPa to the surface, H2O, CO2 and S profiles for all embayments can be fit with a relatively narrow range in decompression rates of 0.3-0.5 MPa/s, equivalent to 11-17 m/s ascent velocity and an 8 to 12 minute duration of magma ascent from ~ 10 km depth. A two stage decompression model takes advantage of the different depth ranges over which CO2 and H2O degas, and produces good fits given an initial stage of slow decompression (0.05-0.3 MPa/s) at high

Lung volumes, pulmonary ventilation, and hypoxia following rapid decompression to 60,000 ft (18,288 m).

PubMed

Connolly, Desmond M; D'Oyly, Timothy J; McGown, Amanda S; Lee, Vivienne M

2013-06-01

Rapid decompressions (RD) to 60,000 ft (18,288 m) were undertaken by six subjects to provide evidence of satisfactory performance of a contemporary, partial pressure assembly life support system for the purposes of flight clearance. A total of 12 3-s RDs were conducted with subjects breathing 56% oxygen (balance nitrogen) at the base (simulated cabin) altitude of 22,500 ft (6858 m), switching to 100% oxygen under 72 mmHg (9.6 kPa) of positive pressure at the final (simulated aircraft) altitude. Respiratory pressures, flows, and gas compositions were monitored continuously throughout. All RDs were completed safely, but one subject experienced significant hypoxia during the minute at final altitude, associated with severe hemoglobin desaturation to a low of 53%. Accurate data on subjects' lung volumes were obtained and individual responses post-RD were reviewed in relation to patterns of pulmonary ventilation. The occurrence of severe hypoxia is explained by hypoventilation in conjunction with unusually large lung volumes (total lung capacity 10.18 L). Subjects' lung volumes and patterns of pulmonary ventilation are critical, but idiosyncratic, determinants of alveolar oxygenation and severity of hypoxia following RD to 60,000 ft (18,288 m). At such extreme altitudes even vaporization of water condensate in the oxygen mask may compromise oxygen delivery. An altitude ceiling of 60,000 ft (18,288 m) is the likely threshold for reliable protection using partial pressure assemblies and aircrew should be instructed to take two deep 'clearing' breaths immediately following RD at such extreme pressure breathing altitudes.

The Possible Relationship Between Patent Foramen Ovale and Decompression Sickness:.

DTIC Science & Technology

1999-01-01

a potential conduit for blood clot (resulting in a stroke), or venous gas bubbles during decompression, (resulting in type II neurologic...Despite the high prevalence of PFO in the general population, and the relatively common occurrence of venous gas bubbles in diving and altitude exposures...being present in up to a third of the population. The potential for right- to-left shunting of venous gas emboli (VGE) which are known to occur in even

Early clinical effects of the Dynesys system plus transfacet decompression through the Wiltse approach for the treatment of lumbar degenerative diseases

PubMed Central

Liu, Chao; Wang, Lei; Tian, Ji-wei

2014-01-01

Background This study investigated early clinical effects of Dynesys system plus transfacet decompression through the Wiltse approach in treating lumbar degenerative diseases. Material/Methods 37 patients with lumbar degenerative disease were treated with the Dynesys system plus transfacet decompression through the Wiltse approach. Results Results showed that all patients healed from surgery without severe complications. The average follow-up time was 20 months (9–36 months). Visual Analogue Scale and Oswestry Disability Index scores decreased significantly after surgery and at the final follow-up. There was a significant difference in the height of the intervertebral space and intervertebral range of motion (ROM) at the stabilized segment, but no significant changes were seen at the adjacent segments. X-ray scans showed no instability, internal fixation loosening, breakage, or distortion in the follow-up. Conclusions The Dynesys system plus transfacet decompression through the Wiltse approach is a therapeutic option for mild lumbar degenerative disease. This method can retain the structure of the lumbar posterior complex and the motion of the fixed segment, reduce the incidence of low back pain, and decompress the nerve root. PMID:24859831

Temporal trends and geographical variation in the use of subacromial decompression and rotator cuff repair of the shoulder in England.

PubMed

Judge, A; Murphy, R J; Maxwell, R; Arden, N K; Carr, A J

2014-01-01

We explored the trends over time and the geographical variation in the use of subacromial decompression and rotator cuff repair in 152 local health areas (Primary Care Trusts) across England. The diagnostic and procedure codes of patients undergoing certain elective shoulder operations between 2000/2001 and 2009/2010 were extracted from the Hospital Episode Statistics database. They were grouped as 1) subacromial decompression only, 2) subacromial decompression with rotator cuff repair, and 3) rotator cuff repair only. The number of patients undergoing subacromial decompression alone rose by 746.4% from 2523 in 2000/2001 (5.2/100 000 (95% confidence interval (CI) 5.0 to 5.4) to 21 355 in 2009/2010 (40.2/100 000 (95% CI 39.7 to 40.8)). Operations for rotator cuff repair alone peaked in 2008/2009 (4.7/100 000 (95% CI 4.5 to 4.8)) and declined considerably in 2009/2010 (2.6/100 000 (95% CI 2.5 to 2.7)). Given the lack of evidence for the effectiveness of these operations and the significant increase in the number of procedures being performed in England and elsewhere, there is an urgent need for well-designed clinical trials to determine evidence of clinical effectiveness.

Perforation and bacterial contamination of microscope covers in lumbar spinal decompressive surgery.

PubMed

Osterhoff, Georg; Spirig, José; Klasen, Jürgen; Kuster, Stefan P; Zinkernagel, Annelies S; Sax, Hugo; Min, Kan

2014-01-01

To determine the integrity of microscope covers and bacterial contamination at the end of lumbar spinal decompressive surgery. A prospective study of 25 consecutive lumbar spinal decompressions with the use of a surgical microscope was performed. For detection of perforations, the microscope covers were filled with water at the end of surgery and the presence of water leakage in 3 zones (objective, ocular and control panel) was examined. For detection of bacterial contamination, swabs were taken from the covers at the same locations before and after surgery. Among the 25 covers, 1 (4%) perforation was observed and no association between perforation and bacterial contamination was seen; 3 (4%) of 75 smears from the 25 covers showed post-operative bacterial contamination, i.e. 2 in the ocular zone and 1 in the optical zone, without a cover perforation. The incidence of microscope cover perforation was very low and was not shown to be associated with bacterial contamination. External sources of bacterial contamination seem to outweigh the problem of contamination due to failure of cover integrity. © 2014 S. Karger AG, Basel.

Perforation and Bacterial Contamination of Microscope Covers in Lumbar Spinal Decompressive Surgery

PubMed Central

Osterhoff, Georg; Spirig, José; Klasen, Jürgen; Kuster, Stefan P.; Zinkernagel, Annelies S.; Sax, Hugo; Min, Kan

2014-01-01

Objective To determine the integrity of microscope covers and bacterial contamination at the end of lumbar spinal decompressive surgery. Materials and Methods A prospective study of 25 consecutive lumbar spinal decompressions with the use of a surgical microscope was performed. For detection of perforations, the microscope covers were filled with water at the end of surgery and the presence of water leakage in 3 zones (objective, ocular and control panel) was examined. For detection of bacterial contamination, swabs were taken from the covers at the same locations before and after surgery. Results Among the 25 covers, 1 (4%) perforation was observed and no association between perforation and bacterial contamination was seen; 3 (4%) of 75 smears from the 25 covers showed post-operative bacterial contamination, i.e. 2 in the ocular zone and 1 in the optical zone, without a cover perforation. Conclusions The incidence of microscope cover perforation was very low and was not shown to be associated with bacterial contamination. External sources of bacterial contamination seem to outweigh the problem of contamination due to failure of cover integrity. PMID:24903448

Isosorbide-Induced Decompression Effect on the Scala Media: Participation of Plasma Osmolality and Plasma Arginine Vasopressin.

PubMed

Takeda, Taizo; Takeda, Setsuko; Uehara, Natsumi; Yanagisawa, Shungaku; Furukawa, Tatsuya; Nibu, Ken-Ichi; Kakigi, Akinobu

2017-04-01

The correlation between the isosorbide-induced decompression effect on the endolymphatic space and plasma osmolality (p-OSM) or plasma arginine vasopressin (p-AVP) was investigated on comparing two different dosages of isosorbide (2.8 and 1.4 g/kg) to elucidate why the decompression effect is delayed with a large dose of isosorbide. Two experiments were performed using 80 guinea pigs. Experiment 1 was designed to morphologically investigate the sequential influence of the oral intake of 1.4- and 2.8-g/kg doses of isosorbide on the endolymphatic volume. The animals used were 50 guinea pigs (control: 10, experimental: 40). All animals underwent surgical obliteration of the endolymphatic sac of the left ear. One month after the surgery, control animals were sacrificed 3 hours after the intake of distilled water, and experimental animals were sacrificed 3 and 6 hours after the isosorbide intake. All of the left temporal bone served for the quantitative assessment of changes in the endolymphatic space, and the cross-sectional area of the scala media was measured from the mid-modiolar sections of the cochlea.Experiment 2 was designed to investigate changes in p-OSM and p-AVP levels 3 hours after the oral intake of isosorbide. Animals used were 15 guinea pigs (control: 5, experimental: 10). The control group received the oral administration of distilled water (4 ml/kg), and the experimental animals were subdivided into two groups consisting of 10 animals each by the dosage of isosorbide (1.4 or 2.8 g/kg). All animals were sacrificed for the measurement of p-OSM and p-AVP concentrations 3 hours after the intake of water or 70% isosorbide solution. Morphologically, an isosorbide-induced decompression effect was noted in animals with both 1.4- and 2.8-g/kg doses of isosorbide. According to the regression analysis, however, the volumetric decrease of the endolymphatic space was more evident in cases with the small dose (1.4 g/kg) 3 hours after the intake

Painless motor radiculopathy of the cervical spine: clinical and radiological characteristics and long-term outcomes after operative decompression.

PubMed

Siller, Sebastian; Kasem, Rami; Witt, Thomas-Nikolaus; Tonn, Joerg-Christian; Zausinger, Stefan

2018-03-23

OBJECTIVE Various neurological diseases are known to cause progressive painless paresis of the upper limbs. In this study the authors describe the previously unspecified syndrome of compression-induced painless cervical radiculopathy with predominant motor deficit and muscular atrophy, and highlight the clinical and radiological characteristics and outcomes after surgery for this rare syndrome, along with its neurological differential diagnoses. METHODS Medical records of 788 patients undergoing surgical decompression due to degenerative cervical spine diseases between 2005 and 2014 were assessed. Among those patients, 31 (3.9%, male to female ratio 4.8 to 1, mean age 60 years) presented with painless compressive cervical motor radiculopathy due to neuroforaminal stenosis without signs of myelopathy; long-term evaluation was available in 23 patients with 49 symptomatic foraminal stenoses. Clinical, imaging, and operative findings as well as the long-term course of paresis and quality of life were analyzed. RESULTS Presenting symptoms (mean duration 13.3 months) included a defining progressive flaccid radicular paresis (median grade 3/5) without any history of radiating pain (100%) and a concomitant muscular atrophy (78%); 83% of the patients were smokers and 17% patients had diabetes. Imaging revealed a predominantly anterior nerve root compression at the neuroforaminal entrance in 98% of stenoses. Thirty stenoses (11 patients) were initially decompressed via an anterior surgical approach and 19 stenoses (12 patients) via a posterior surgical approach. Overall reoperation rate due to new or recurrent stenoses was 22%, with time to reoperation shorter in smokers (p = 0.033). Independently of the surgical procedure chosen, long-term follow-up (mean 3.9 years) revealed a stable or improved paresis in 87% of the patients (median grade 4/5) and an excellent general performance and quality of life. CONCLUSIONS Painless cervical motor radiculopathy predominantly occurs

A rat model of chronic moderate alcohol consumption and risk of decompression sickness.

PubMed

Buzzacott, Peter; Mazur, Aleksandra; Wang, Qiong; Lambrechts, Kate; Theron, Michael; Guerrero, François

2015-06-01

This study aimed to establish if chronic, moderate, pre-dive alcohol consumption had any affect upon susceptibility to decompression sickness (DCS) in rats. A treatment group of 15 rats were given water containing 12 mL ·L ⁻¹ of ethanol for four weeks. Controls (n = 15) were given water. Both groups were compressed with air to 1,000 kPa, followed by staged decompression. An additional 30 control rats from a similar previous experiment were added, raising the control-treatment ratio to 3:1. Rats in the treatment group consumed the equivalent of an 80 kg man drinking 2 L of 5 % alcohol by volume beer per day, which is three times the recommended daily limit for men. Overall, comparing the treatment group with the combined control groups neither weight (P = 0.23) nor alcohol consumption (P = 0.69) were associated with DCS. We observed that chronic, moderate alcohol consumption prior to compression was neither prophylactic nor deleterious for DCS in young, male rats.

[Role of the small intestinal decompression tube and Gastrografin in the treatment of early postoperative inflammatory small bowel obstruction].

PubMed

Li, Wei; Li, Zhixia; An, Dali; Liu, Jing; Zhang, Xiaohu

2014-03-01

To evaluate the role of the small intestinal decompression tube (SIDT) and Gastrografin in the treatment of early postoperative inflammatory small bowel obstruction (EPISBO). Twelve patients presented EPISBO after abdominal surgery in our department from April 2011 to July 2012. Initially, nasogastric tube decompression and other conventional conservative treatment were administrated. After 14 days, obstruction symptom improvement was not obvious, then the SIDT was used. At the same time, Gastrografin was injected into the small bowel through the SIDT in order to demonstrate the site of obstruction of small bowel and its efficacy. In 11 patients after this management, obstruction symptoms disappeared, bowel function recovered within 3 weeks, and oral feeding occurred gradually. Another patient did not pass flatus after 4 weeks and was reoperated. After postoperative follow-up of 6 months, no case relapsed with intestinal obstruction. For severe and long course of early postoperative inflammatory intestinal obstruction, intestinal decompression tube plus Gastrografin is safe and effective, and can avoid unnecessary reoperation.

Editorial Commentary: Subacromial Decompression Is Unnecessary in Most Routine Rotator Cuff Repairs.

PubMed

Solomon, Daniel J

2017-07-01

There is no need to perform subacromial decompression in partial bursal-sided rotator cuff repairs to obtain a good result. This, paired with the findings of previous studies of full-thickness rotator cuff repairs, suggests that extrinsic factors rarely affect the rotator cuff. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Hospital discharge rates for nontraumatic lower extremity amputation by diabetes status--United States, 1997.

PubMed

2001-11-02

Lower extremity amputation (LEA) is a costly and disabling procedure that disproportionately affects persons with diabetes. One of the national health objectives for 2000 was to reduce the LEA rate from a 1991 baseline of approximately eight per 1,000 persons with diabetes to a target of approximately five per 1,000 persons with diabetes. Review of 1996 data indicated an LEA rate of approximately 11. To estimate the national rates of hospital discharges for LEA among persons with and without diabetes and to assess the excess risk for LEA among persons with diabetes, CDC and the Agency for Healthcare Research and Quality (AHRQ) analyzed data from the 1997 Nationwide Inpatient Sample (NIS) and the 1997 National Health Interview Survey (NHIS). This report summarizes the findings of the analysis, which indicated that the age-adjusted rates of hospital discharges among persons with LEA who had diabetes were 28 times that of those without diabetes. This higher rate underscores the need to increase efforts to prevent risk factors (e.g., peripheral vascular disease, neuropathy, and infection) that result in LEA among persons with diabetes.

Surgical decompression for space-occupying cerebral infarction: outcomes at 3 years in the randomized HAMLET trial.

PubMed

Geurts, Marjolein; van der Worp, H Bart; Kappelle, L Jaap; Amelink, G Johan; Algra, Ale; Hofmeijer, Jeannette

2013-09-01

We assessed whether the effects of surgical decompression for space-occupying hemispheric infarction, observed at 1 year, are sustained at 3 years. Patients with space-occupying hemispheric infarction, who were enrolled in the Hemicraniectomy After Middle cerebral artery infarction with Life-threatening Edema Trial within 4 days after stroke onset, were followed up at 3 years. Outcome measures included functional outcome (modified Rankin Scale), death, quality of life, and place of residence. Poor functional outcome was defined as modified Rankin Scale >3. Of 64 included patients, 32 were randomized to decompressive surgery and 32 to best medical treatment. Just as at 1 year, surgery had no effect on the risk of poor functional outcome at 3 years (absolute risk reduction, 1%; 95% confidence interval, -21 to 22), but it reduced case fatality (absolute risk reduction, 37%; 95% confidence interval, 14-60). Sixteen surgically treated patients and 8 controls lived at home (absolute risk reduction, 27%; 95% confidence interval, 4-50). Quality of life improved between 1 and 3 years in patients treated with surgery. In patients with space-occupying hemispheric infarction, the effects of decompressive surgery on case fatality and functional outcome observed at 1 year are sustained at 3 years. http://www.controlled-trials.com. Unique identifier: ISRCTN94237756.

Field validation of Tasmania's aquaculture industry bounce-diving schedules using Doppler analysis of decompression stress.

PubMed

Smart, David R; Van den Broek, Cory; Nishi, Ron; Cooper, P David; Eastman, David

2014-09-01

Tasmania's aquaculture industry produces over 40,000 tonnes of fish annually, valued at over AUD500M. Aquaculture divers perform repetitive, short-duration bounce dives in fish pens to depths up to 21 metres' sea water (msw). Past high levels of decompression illness (DCI) may have resulted from these 'yo-yo' dives. This study aimed to assess working divers, using Doppler ultrasonic bubble detection, to determine if yo-yo diving was a risk factor for DCI, determine dive profiles with acceptable risk and investigate productivity improvement. Field data were collected from working divers during bounce diving at marine farms near Hobart, Australia. Ascent rates were less than 18 m·min⁻¹, with routine safety stops (3 min at 3 msw) during the final ascent. The Kisman-Masurel method was used to grade bubbling post dive as a means of assessing decompression stress. In accordance with Defence Research and Development Canada Toronto practice, dives were rejected as excessive risk if more than 50% of scores were over Grade 2. From 2002 to 2008, Doppler data were collected from 150 bounce-dive series (55 divers, 1,110 bounces). Three series of bounce profiles, characterized by in-water times, were validated: 13-15 msw, 10 bounces inside 75 min; 16-18 msw, six bounces inside 50 min; and 19-21 msw, four bounces inside 35 min. All had median bubble grades of 0. Further evaluation validated two successive series of bounces. Bubble grades were consistent with low-stress dive profiles. Bubble grades did not correlate with the number of bounces, but did correlate with ascent rate and in-water time. These data suggest bounce diving was not a major factor causing DCI in Tasmanian aquaculture divers. Analysis of field data has improved industry productivity by increasing the permissible number of bounces, compared to earlier empirically-derived tables, without compromising safety. The recommended Tasmanian Bounce Diving Tables provide guidance for bounce diving to a depth of 21 msw

A review of the influence of physical condition parameters on a typical aerospace stress effect: Decompression sickness

NASA Technical Reports Server (NTRS)

West, V. R.; Parker, J. F., Jr.

1973-01-01

The study examines data on episodes of decompression sickness, particularly from recent Navy work in which the event occurred under multiple stress conditions, to determine the extent to which decompression sickness might be predicted on the basis of personal characteristics such as age, weight, and physical condition. Such information should ultimately be useful for establishing medical selection criteria to screen individuals prior to participation inactivities involving extensive changes in ambient pressure, including those encountered in space operations. The main conclusions were as follows. There is a definite and positive relationship between increasing age and weight and the likelihood of decompression sickness. However, for predictive purposes, the relationship is low. To reduce the risk of bends, particularly for older individuals, strenuous exercise should be avoided immediately after ambient pressure changes. Temperatures should be kept at the low end of the comfort zone. For space activities, pressure changes of over 6-7 psi should be avoided. Prospective participants in future missions such as the Space Shuttle should not be excluded on the basis of age, certainly to age 60, if their general condition is reasonably good and they are not grossly obese. (Modified author abstract)

Intradiploic pseudomeningocele and ossified occipitocervical pseudomeningocele after decompressive surgery for Chiari I malformation: report of two cases and literature review.

PubMed

Kurzbuch, Arthur R; Magdum, Shailendra; Jayamohan, Jayaratnam

2017-04-01

Intradiploic cerebrospinal fluid (CSF) collections are rare findings. The authors describe two pediatric patients with iatrogenically induced occipital CSF collections after decompressive surgery for Chiari I malformation. The first patient presents a large occipital intradiploic pseudomeningocele and the second patient an intradiploic pseudomeningocele merging with an ossified occipitocervical pseudomeningocele. Though being rarities after decompression for Chiari I malformation, intradiploic fluid collection and ossified pseudomeningocele should be considered if patients represent with aggravating presurgical or new symptoms.

[Development of ocular motility following modified 3-wall decompression of the orbita in endocrine orbitopathy for functional and rehabilitative indication].

PubMed

Grenzebach, Ulrike H; Schnorbus, Ulrike; Büchner, Thomas; Busse, Holger; Stoll, Wolfgang

2003-05-01

Permanent visual damage due to an increase in volume of the orbital contents may be the result of the failure of conservative therapeutic concepts in the treatment of endocrine orbitopathy. Considerable progress has been achieved in developing successful orbital decompression techniques with regard to functional and cosmetic outcome. Decompression techniques with resection of the bony orbital walls are adequate tools in restoring visual acuity and reducing exophthalmus. A considerable degree of deterioration of motility disorders has been described in the literature depending on the techniques being used. The purpose of this study was to investigate whether a modified technique of 3-wall orbital decompression with preservation of a medial part of the periorbital tissue to support the medial rectus muscle, is able to reduce the postoperative risk of diplopia. A modified technique of orbital 3-wall decompression with resection of the medial orbital wall, the medial orbital floor and the floor of the frontal sinus has been used in patients with compressive optic neuropathy (n = 20) and for cosmetic reasons (n = 7) in cases of uni- or bilateral proptosis. Analysis of the results was performed concerning visual outcome, exophthalmus reduction and development of horizontal and vertical motility changes. In all cases of optic neuropathy improvement of visual function at an average of 4.63 +/- 4.5 lines could be achieved. Exophthalmus reduction was 3.2 +/- 2.4 mm in the functional group and 3.9 +/- 1.7 mm in the rehabilitative group. In this group motility of the medial rectus muscle remained unaffected except in one eye. In the functional group motility deterioration was observed in 62 %. The modified 3-wall decompression technique with preservation of a medial periorbital tissue strip is an adequate alternative technique in the therapy of optic neuropathy and exophthalmus reduction in endocrine orbitopathy with a low risk of postoperative motility disorders.

Chiari I malformation with underlying pseudotumor cerebri: Poor symptom relief following posterior decompression surgery.

PubMed

Alnemari, Ahmed; Mansour, Tarek R; Gregory, Stephanie; Miller, William K; Buehler, Mark; Gaudin, Daniel

2017-01-01


 Pseudotumor cerebri (PTC) patients exhibit clear clinical signs and symptoms of higher intracranial pressure (ICP) without ventricular enlargement or mass lesions. The clinical picture of patients with PTC can sometimes be similar to that of Chiari Malformation type I (CMI). There is some evidence that Chiari I malformation and PTC may coexist, which raises the question of whether PTC is an idiopathic disease or a complication of posterior decompression surgery-treatment of choice for Chiari I malformation. A retrospective review of electronic medical records of patients diagnosed with PTC at the University of Toledo Medical Center (UTMC) was performed. The objective was to determine whether PTC patients had a concurrent diagnosis of Chiari I malformation and whether the diagnosis of PTC occurred before or after posterior decompression surgery. Out of the 8 eligible patient medical records reviewed, 5 patients diagnosed with PTC had undergone posterior decompression surgery for Chiari I malformation at anywhere from several days to three years prior to being diagnosed with PTC. The diagnosis of PTC was based on temporary symptomatic relief following lumbar puncture which also showed elevated CSF opening pressures. Finally, a VP shunt was placed in each of the 5 patients to relieve the elevated intracranial pressure which resulted in the complete resolution of the patients' symptoms. Our study focuses on patients who were diagnosed with and treated for CMI then reported back to the clinic within several days to three years complaining of symptoms of headache. Upon re-presenting to the clinic, a CSF flow study was performed which showed normal flow of CSF. Then, these patients underwent a lumbar puncture which demonstrated an elevated opening pressure (and ICP) and a temporary relief of the headache with lumbar drainage. A VP shunt was placed for each patient to treat for PTC, and the patients' headaches were relieved. This study suggests that the presence of

Efficacy of Posterior Fossa Decompression with Duraplasty for Patients with Chiari Malformation Type I: A Systematic Review and Meta-Analysis.

PubMed

Chai, Zhi; Xue, Xiaoming; Fan, Huijie; Sun, Lin; Cai, Hongyu; Ma, Yanmiao; Ma, Cungen; Zhou, Ran

2018-05-01

To quantitatively assess and compare the effectiveness and safety of posterior fossa decompression with duraplasty (PFDD) and posterior fossa decompression (PFD) in treating patients with Chiari malformation type I. PubMed, Embase, and Cochrane Library were searched through May 2017. Fourteen cohort studies comprising 3666 patients with Chiari malformation type I were included. Studies were pooled, and the relative risk (RR) and corresponding 95% confidence interval (CI) were calculated. The decrease in syringomyelia was better in patients in the PFDD group than in patients in the PFD group (RR = 1.57, 95% CI = 1.07-2.32, P heterogeneity  = 0.042, I 2  = 56.6%). The incidence of cerebrospinal fluid leak (RR = 5.23, 95% CI = 2.61-10.51, P heterogeneity  = 0.830, I 2  = 0%) and aseptic meningitis (RR = 4.02, 95% CI = 1.46-11.03, P heterogeneity  = 0.960, I 2  = 0%) significantly increased among patients in the PFDD group compared with patients in the PFD group. When stratifying by age, a significantly reduced risk in the reoperation rate was observed in the adult group. However, the clinical improvement and the incidence of wound infection were not significantly different between the 2 groups. This study confirmed that the decrease in syringomyelia was better for patients treated with PFDD than for patients treated with PFD alone. However, no significant difference was found in the clinical improvement and the reoperation rate between the 2 groups. Copyright © 2018 Elsevier Inc. All rights reserved.

Management of Bleeding Duodenal Varices with Combined TIPS Decompression and Trans-TIPS Transvenous Obliteration Utilizing 3% Sodium Tetradecyl Sulfate Foam Sclerosis

PubMed Central

Saad, Wael E; Lippert, Allison; Schwaner, Sandra; Al-Osaimi, Abdullah; Sabri, Saher; Saad, Nael

2014-01-01

Objectives: Endoscopic experience in the management of duodenal varices (DVs) is limited and challenging given the anatomic constraints and limited experience. The endovascular management of DVs is not yet established and the controversy of whether to manage them by decompression with a transjugular intrahepatic portosystemic shunt (TIPS) or by transvenous obliteration is unresolved. In the literature, the 6–12 month rebleeding rate of DVs after TIPS is 21-37% and after transvenous obliteration is 13%. The purpose of the study is to evaluate the clinical outcome of combined TIPS decompression and transvenous obliteration/sclerosis. Materials and Methods: This is a retrospective study (case series) of two institutions, evaluating patients who underwent TIPS and/or transvenous obliteration/sclerosis for bleeding DVs (from January 2009 to June 2013). TIPS was performed according to a standard procedure using covered stents. Transvenous obliteration (variceal sclerosis) from the systemic and/or portal venous circulation was performed utilizing 3% sodium tetradecyl sulfate foam. Transvenous obliteration was commonly augmented with coils and/or vascular plugs. Technical (technical success of establishing TIPS and completely obliterating the DVs) and clinical outcomes (rebleeding rate and survival) were evaluated. Results: Five patients with liver cirrhosis presenting with bleeding DVs were included in the study with all eventually (and coincidentally) receiving TIPS and transvenous obliteration. Two of the five patients underwent concomitant TIPS and transvenous obliteration in the same procedural setting. However, three patients underwent transvenous obliteration due to bleeding despite a patent TIPS that had been previously placed. The average time from TIPS placement to transvenous obliteration was 125 days (range: 3-324 days). After having both procedures, there was no rebleeding in the patients during a mean follow-up period of 22 months (6–50 months). Coils and

Extreme Metal Music and Anger Processing

PubMed Central

Sharman, Leah; Dingle, Genevieve A.

2015-01-01

The claim that listening to extreme music causes anger, and expressions of anger such as aggression and delinquency have yet to be substantiated using controlled experimental methods. In this study, 39 extreme music listeners aged 18–34 years were subjected to an anger induction, followed by random assignment to 10 min of listening to extreme music from their own playlist, or 10 min silence (control). Measures of emotion included heart rate and subjective ratings on the Positive and Negative Affect Scale (PANAS). Results showed that ratings of PANAS hostility, irritability, and stress increased during the anger induction, and decreased after the music or silence. Heart rate increased during the anger induction and was sustained (not increased) in the music condition, and decreased in the silence condition. PANAS active and inspired ratings increased during music listening, an effect that was not seen in controls. The findings indicate that extreme music did not make angry participants angrier; rather, it appeared to match their physiological arousal and result in an increase in positive emotions. Listening to extreme music may represent a healthy way of processing anger for these listeners. PMID:26052277

Posterior fossa volume and response to suboccipital decompression in patients with Chiari I malformation.

PubMed

Badie, B; Mendoza, D; Batzdorf, U

1995-08-01

Smaller posterior fossa (PF) volume has been suggested to be one of the mechanisms responsible for tonsillar herniation through the foramen magnum in patients with Chiari I malformation (CM I). Although previous radiological analyses of the cranial anatomy have suggested a smaller PF volume in patients with CM I, the relationship of the PF volume to decompressive surgery has not been reported. We have measured the ratio of PF volume to supratentorial volume (PF ratio [PFR]) in 20 patients with CM I and 20 control patients by retrospectively studying their magnetic resonance images with a computerized image analyzer. The mean PFR in patients with CM I (with or without syringomyelia) was significantly smaller than for those in the control group (15.6 +/- 1.9 versus 17.5 +/- 1.2, P = 0.0008). Although PFR did not correlate with the extent of tonsillar herniation in patients with CM I, it did directly correlate with their age, i.e., younger patients with CM I (but not control patients) had smaller PFRs. All but three patients responded both clinically and radiographically to decompressive surgery. Those patients who did not benefit from surgical intervention had normal PFRs. We conclude that: 1) PFRs are smaller in most patients with CM I; 2) a smaller PF may be a primary cause of tonsillar herniation; 3) patients with CM I who have smaller PFRs tend to develop symptoms earlier than those with normal values; 4) patients with smaller PFRs tend to respond better to suboccipital decompression.

The probability and severity of decompression sickness

PubMed Central

Hada, Ethan A.; Vann, Richard D.; Denoble, Petar J.

2017-01-01

Decompression sickness (DCS), which is caused by inert gas bubbles in tissues, is an injury of concern for scuba divers, compressed air workers, astronauts, and aviators. Case reports for 3322 air and N2-O2 dives, resulting in 190 DCS events, were retrospectively analyzed and the outcomes were scored as (1) serious neurological, (2) cardiopulmonary, (3) mild neurological, (4) pain, (5) lymphatic or skin, and (6) constitutional or nonspecific manifestations. Following standard U.S. Navy medical definitions, the data were grouped into mild—Type I (manifestations 4–6)–and serious–Type II (manifestations 1–3). Additionally, we considered an alternative grouping of mild–Type A (manifestations 3–6)–and serious–Type B (manifestations 1 and 2). The current U.S. Navy guidance allows for a 2% probability of mild DCS and a 0.1% probability of serious DCS. We developed a hierarchical trinomial (3-state) probabilistic DCS model that simultaneously predicts the probability of mild and serious DCS given a dive exposure. Both the Type I/II and Type A/B discriminations of mild and serious DCS resulted in a highly significant (p << 0.01) improvement in trinomial model fit over the binomial (2-state) model. With the Type I/II definition, we found that the predicted probability of ‘mild’ DCS resulted in a longer allowable bottom time for the same 2% limit. However, for the 0.1% serious DCS limit, we found a vastly decreased allowable bottom dive time for all dive depths. If the Type A/B scoring was assigned to outcome severity, the no decompression limits (NDL) for air dives were still controlled by the acceptable serious DCS risk limit rather than the acceptable mild DCS risk limit. However, in this case, longer NDL limits were allowed than with the Type I/II scoring. The trinomial model mild and serious probabilities agree reasonably well with the current air NDL only with the Type A/B scoring and when 0.2% risk of serious DCS is allowed. PMID:28296928

Results of decompression surgery for pain in chronic pancreatitis

PubMed Central

Terrace, J.D.; Paterson, H.M.; Garden, O.J.; Parks, R.W.

2007-01-01

Introduction. A vast majority of patients with chronic pancreatitis require regular opiate/opioid analgesia and recurrent hospital admission for pain. However, the role and timing of operative strategies for pain in chronic pancreatitis is controversial. This study hypothesized that pancreatic decompression surgery reduces analgesia requirement and hospital readmission for pain in selected patients. Patients and methods. This was a retrospective review of patients undergoing longitudinal pancreatico-jejunostomy (LPJ), with or without coring of the pancreatic head (Frey's procedure), between 1995 and 2007 in a single UK centre. Surgery was performed for chronic pain with clinical/radiological evidence of chronic pancreatitis amenable to decompression/head coring. Results. Fifty patients were identified. Thirty-six were male with a median age of 46 years and median follow-up of 30 months. Twenty-eight underwent LPJ and 22underwent Frey's procedure. No significant difference in reduction of analgesia requirement (71% vs 64%, p=0.761) or hospital readmission for pain (21% vs 23%, p=1.000) was observed when comparing LPJ and Frey's procedure. Patients were significantly more likely to be pain-free following surgery if they required non-opiate rather than opiate analgesia preoperatively (75% vs 19%, p=0.0002). Fewer patients required subsequent hospital readmission for pain if taking non-opiate rather than opiate analgesia preoperatively (12.5% vs 31%, p=0.175). Conclusions. In selected patients, LPJ and Frey's procedure have equivalent benefit in short-term pain reduction. Patients should be selected for surgery before the commencement of opiate analgesia. PMID:18345310

The effects of massage therapy after decompression and fusion surgery of the lumbar spine: a case study.

PubMed

Keller, Glenda

2012-01-01

Spinal fusion and decompression surgery of the lumbar spine are common procedures for problems such as disc herniations. Various studies for postoperative interventions have been conducted; however, no massage therapy studies have been completed. The objective of this study is to determine if massage therapy can beneficially treat pain and dysfunction associated with lumbar spinal decompression and fusion surgery. Client is a 47-year-old female who underwent spinal decompression and fusion surgery of L4/L5 due to chronic disc herniation symptoms. The research design was a case study in a private clinic involving the applications of seven, 30-minute treatments conducted over eight weeks. Common Swedish massage and myofascial techniques were applied to the back, shoulders, posterior hips, and posterior legs. Outcomes were assessed using the following measures: VAS pain scale, Hamstring Length Test, Oswestry Disability Index, and the Roland-Morris Disability Questionnaire. Hamstring length improved (in degrees of extension) from pretreatment measurements in the right leg of 40° and left leg 65° to post-treatment measurement at the final visit, when the results were right 50° and left 70°. The Oswestry Disability Index improved 14%, from 50% to 36% disability. Roland-Morris Disability decreased 1 point, from 3/24 to 2/24. The VAS pain score decreased by 2 points after most treatments, and for three of the seven treatments, client had a post-treatment score of 0/10. Massage for pain had short-term effects. Massage therapy seemed to lengthen the hamstrings bilaterally. Massage therapy does appear to have positive effects in the reduction of disability. This study is beneficial for understanding the relationship between massage therapy and clients who have undergone spinal decompression and fusion. Further research is warranted.

Toward one-loop tunneling rates of near-extremal magnetic black hole pair production

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

Yi, P.

Pair production of magnetic Reissner-Nordstroem black holes (of charges [plus minus][ital q]) was recently studied in the leading WKB approximation. Here we consider generic quantum fluctuations in the corresponding instanton geometry given by the Euclidean Ernst metric, in order to simulate the behavior of the one-loop tunneling rate. A detailed study of the Ernst metric suggests that for a sufficiently weak field [ital B], the problem can be reduced to that of quantum fluctuations around a single near-extremal Euclidean black hole in thermal equilibrium with a heat bath of finite size. After appropriate renormalization procedures, typical one-loop contributions to themore » WKB exponent are shown to be inversely proportional to [ital B], as [ital B][r arrow]0, indicating that the leading Schwinger term is corrected by a small fraction [similar to][h bar]/[ital q][sup 2]. We demonstrate that this correction to the Schwinger term is actually due to a semiclassical shift of the black hole mass-to-charge ratio that persists even in the extremal limit. Finally we discuss a few loose ends.« less

Femoroacetabular impingement in 45 professional athletes: associated pathologies and return to sport following arthroscopic decompression

PubMed Central

Schenker, Mara; Briggs, Karen; Kuppersmith, David

2007-01-01

Femoroacetabular impingement (FAI) occurs when an osseous abnormality of the proximal femur (cam) or acetabulum (pincer) triggers damage to the acetabular labrum and articular cartilage in the hip. Although the precise etiology of FAI is not well understood, both types of FAI are common in athletes presenting with hip pain, loss of range-of-motion, and disability in athletics. An open surgical approach to decompressing FAI has shown good clinical outcomes; however, this highly invasive approach inherently may delay or preclude a high level athlete’s return to play. The purpose of this study was to define associated pathologies and determine if an arthroscopic approach to treating FAI can allow professional athletes to return to high-level sport. Hip arthroscopy for the treatment of FAI allows professional athletes to return to professional sport. Between October 2000 and September 2005, 45 professional athletes underwent hip arthroscopy for the decompression of FAI. Operative and return-to-play data were obtained from patient records. Average time to follow-up was 1.6 years (range: 6 months to 5.5 years). Forty two (93%) athletes returned to professional competition following arthroscopic decompression of FAI. Three athletes did not return to play; however, all had diffuse osteoarthritis at the time of arthroscopy. Thirty-five athletes (78%) remain active in professional sport at an average follow-up of 1.6 years. Arthroscopic treatment of FAI allows professional athletes to return to professional sport. PMID:17479250

Minimally invasive posterior cervical decompression using tubular retractor: The technical note and early clinical outcome

PubMed Central

Hur, Jung-Woo; Kim, Jin-Sung; Shin, Myeong-Hoon; Ryu, Kyeong-Sik

2014-01-01

Background: The aim of this work is to present a novel decompression technique that approaches cervical spine posteriorly, but through minimal invasive method using tubular retractor avoiding detachment of posterior musculature. Methods: Six patients underwent minimally invasive posterior cervical decompression using the tubular retractor system and surgical microscope. Minimally invasive access to the posterior cervical spine was performed with exposure through a paramedian muscle-splitting approach. With the assistance of a specialized tubular retraction system and deep soft tissue expansion mechanism, multilevel posterior cervical decompression could be accomplished. This approach also allows safe docking of the retractor system on the lateral mass, thus avoiding the cervical spinal canal during exposure. A standard operating microscope was used with ×10 magnification and 400 mm focal length. The hospital charts, magnetic resonance imaging studies, and follow-up records of all the patients were reviewed. Outcome was assessed by neurological status and visual analog scale (VAS) for neck and arm pain. Results: There was no significant complication related to operation. The follow-up time was 4-12 months (mean, 9 months). Muscle weakness improved in all patients; sensory deficits resolved in four patients and improved in two patients. Analysis of the mean VAS for radicular pain and VAS for neck pain showed significant improvement. Conclusions: The preliminary experiences with good clinical outcome seem to promise that this minimally invasive technique is a valid alternative option for the treatment of cervical spondylotic myelopathy. PMID:24778922

Preconditioning to Reduce Decompression Stress in Scuba Divers.

PubMed

Germonpré, Peter; Balestra, Costantino

2017-02-01

Using ultrasound imaging, vascular gas emboli (VGE) are observed after asymptomatic scuba dives and are considered a key element in the potential development of decompression sickness (DCS). Diving is also accompanied with vascular dysfunction, as measured by flow-mediated dilation (FMD). Previous studies showed significant intersubject variability to VGE for the same diving exposure and demonstrated that VGE can be reduced with even a single pre-dive intervention. Several preconditioning methods have been reported recently, seemingly acting either on VGE quantity or on endothelial inflammatory markers. Nine male divers who consistently showed VGE postdive performed a standardized deep pool dive (33 m/108 ft, 20 min in 33°C water temperature) to investigate the effect of three different preconditioning interventions: heat exposure (a 30-min session of dry infrared sauna), whole-body vibration (a 30-min session on a vibration mattress), and dark chocolate ingestion (30 g of chocolate containing 86% cocoa). Dives were made one day per week and interventions were administered in a randomized order. These interventions were shown to selectively reduce VGE, FMD, or both compared to control dives. Vibration had an effect on VGE (39.54%, SEM 16.3%) but not on FMD postdive. Sauna had effects on both parameters (VGE: 26.64%, SEM 10.4%; FMD: 102.7%, SEM 2.1%), whereas chocolate only improved FMD (102.5%, SEM 1.7%). This experiment, which had the same subjects perform all control and preconditioning dives in wet but completely standardized diving conditions, demonstrates that endothelial dysfunction appears to not be solely related to VGE.Germonpré P, Balestra C. Preconditioning to reduce decompression stress in scuba divers. Aerosp Med Hum Perform. 2017; 88(2):114-120.

Continuous decompression with intramedullary nailing for the treatment of unicameral bone cysts.

PubMed

Masquijo, Julio Javier; Baroni, Eduardo; Miscione, Horacio

2008-08-01

To evaluate the efficacy of decompression of unicameral bone cysts (UBCs) of the long bones with intramedullary nailing and to compare responses to treatment according to location. We evaluated 48 consecutive patients treated between January 1988 and June 2000. Mean age was 10.3 years. Mean follow-up was 9.8 years. Evaluation was performed according to the radiographic criteria of Capanna. UBCs were located in the proximal humerus (n = 24), humeral shaft (n = 2), proximal femur (n = 19), distal tibia (n = 2) and fibula (n = 1). A total of 62.5% presented a pathological fracture. Successful results were observed in 89.5% (26 total healing, 17 healing with residual radiolucent areas), and there were four recurrences and, in one case, no response to treatment. There was more healing in the humerus than in the femur (92.3% versus 84.2%), and more tendency to restitution ad integrum, although the difference was not statistically significant (P = 0.1499). Intramedullary nailing is a minimally invasive method, which permits early stability and decompresses the cyst allowing healing. Significant differences were not observed among results from different locations.

Microvascular decompression for the patient with painful tic convulsif after Bell palsy.

PubMed

Jiao, Wei; Zhong, Jun; Sun, Hui; Zhu, Jin; Zhou, Qiu-Meng; Yang, Xiao-Sheng; Li, Shi-Ting

2013-05-01

Painful tic convulsif is referred to as the concurrent trigeminal neuralgia and hemifacial spasm. However, painful tic convulsif after ipsilateral Bell palsy has never been reported before. We report a case of a 77-year-old woman with coexistent trigeminal neuralgia and hemifacial spasm who had experienced Bell palsy half a year ago. The patient underwent microvascular decompression. Intraoperatively, the vertebrobasilar artery was found to deviate to the symptomatic side and a severe adhesion was observed in the cerebellopontine angle. Meanwhile, an ectatic anterior inferior cerebellar artery and 2 branches of the superior cerebellar artery were identified to compress the caudal root entry zone (REZ) of the VII nerve and the rostroventral cisternal portion of the V nerve, respectively. Postoperatively, the symptoms of spasm ceased immediately and the pain disappeared within 3 months. In this article, the pathogenesis of the patient's illness was discussed and it was assumed that the adhesions developed from inflammatory reactions after Bell palsy and the anatomic features of the patient were the factors that generated the disorder. Microvascular decompression surgery is the suggested treatment of the disease, and the dissection should be started from the caudal cranial nerves while performing the operation.

Greater occipital nerve neuralgia caused by pathological arterial contact: treatment by surgical decompression.

PubMed

Cornely, Christiane; Fischer, Marius; Ingianni, Giulio; Isenmann, Stefan

2011-04-01

Occipital nerve neuralgia is a rare cause of severe headache, and may be difficult to treat. We report the case of a patient with occipital nerve neuralgia caused by pathological contact of the nerve with the occipital artery. The pain was refractory to medical treatment. Surgical decompression yielded complete remission. © 2010 American Headache Society.

Intravenous Perfluorocarbon After Onset of Decompression Sickness Decreases Mortality in 20-kg Swine

DTIC Science & Technology

2010-06-01

administration of 0.1-1.5 ml· 10 kg- • Euthasol. After confirmation of death, the heart was exposed via thoracotomy and a large-bore cannula p laced in the...from undersea diving. Neural Clin 1992; 10:1031-45. 18. Hallenbeck JM, Bove AA, Elliott DH. Mechanisms underlying spinal cord damage in decompression

Baastrup's Disease Is Associated with Recurrent of Sciatica after Posterior Lumbar Spinal Decompressions Utilizing Floating Spinous Process Procedures.

PubMed

Koda, Masao; Mannoji, Chikato; Murakami, Masazumi; Kinoshita, Tomoaki; Hirayama, Jiro; Miyashita, Tomohiro; Eguchi, Yawara; Yamazaki, Masashi; Suzuki, Takane; Aramomi, Masaaki; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Furuya, Takeo

2016-12-01

Retrospective case-control study. To determine whether kissing spine is a risk factor for recurrence of sciatica after lumbar posterior decompression using a spinous process floating approach. Kissing spine is defined by apposition and sclerotic change of the facing spinous processes as shown in X-ray images, and is often accompanied by marked disc degeneration and decrement of disc height. If kissing spine significantly contributes to weight bearing and the stability of the lumbar spine, trauma to the spinous process might induce a breakdown of lumbar spine stability after posterior decompression surgery in cases of kissing spine. The present study included 161 patients who had undergone posterior decompression surgery for lumbar canal stenosis using a spinous process floating approaches. We defined recurrence of sciatica as that resolved after initial surgery and then recurred. Kissing spine was defined as sclerotic change and the apposition of the spinous process in a plain radiogram. Preoperative foraminal stenosis was determined by the decrease of perineural fat intensity detected by parasagittal T1-weighted magnetic resonance imaging. Preoperative percentage slip, segmental range of motion, and segmental scoliosis were analyzed in preoperative radiographs. Univariate analysis followed by stepwise logistic regression analysis determined factors independently associated with recurrence of sciatica. Stepwise logistic regression revealed kissing spine ( p =0.024; odds ratio, 3.80) and foraminal stenosis ( p <0.01; odds ratio, 17.89) as independent risk factors for the recurrence of sciatica after posterior lumbar spinal decompression with spinous process floating procedures for lumbar spinal canal stenosis. When a patient shows kissing spine and concomitant subclinical foraminal stenosis at the affected level, we should sufficiently discuss the selection of an appropriate surgical procedure.

Nanobubbles Form at Active Hydrophobic Spots on the Luminal Aspect of Blood Vessels: Consequences for Decompression Illness in Diving and Possible Implications for Autoimmune Disease-An Overview.

PubMed

Arieli, Ran

2017-01-01

Decompression illness (DCI) occurs following a reduction in ambient pressure. Decompression bubbles can expand and develop only from pre-existing gas micronuclei. The different hypotheses hitherto proposed regarding the nucleation and stabilization of gas micronuclei have never been validated. It is known that nanobubbles form spontaneously when a smooth hydrophobic surface is submerged in water containing dissolved gas. These nanobubbles may be the long sought-after gas micronuclei underlying decompression bubbles and DCI. We exposed hydrophobic and hydrophilic silicon wafers under water to hyperbaric pressure. After decompression, bubbles appeared on the hydrophobic but not the hydrophilic wafers. In a further series of experiments, we placed large ovine blood vessels in a cooled high pressure chamber at 1,000 kPa for about 20 h. Bubbles evolved at definite spots in all the types of blood vessels. These bubble-producing spots stained positive for lipids, and were henceforth termed "active hydrophobic spots" (AHS). The lung surfactant dipalmitoylphosphatidylcholine (DPPC), was found both in the plasma of the sheep and at the AHS. Bubbles detached from the blood vessel in pulsatile flow after reaching a mean diameter of ~1.0 mm. Bubble expansion was bi-phasic-a slow initiation phase which peaked 45 min after decompression, followed by fast diffusion-controlled growth. Many features of decompression from diving correlate with this finding of AHS on the blood vessels. (1) Variability between bubblers and non-bubblers. (2) An age-related effect and adaptation. (3) The increased risk of DCI on a second dive. (4) Symptoms of neurologic decompression sickness. (5) Preconditioning before a dive. (6) A bi-phasic mechanism of bubble expansion. (7) Increased bubble formation with depth. (8) Endothelial injury. (9) The presence of endothelial microparticles. Finally, constant contact between nanobubbles and plasma may result in distortion of proteins and their transformation

Nanobubbles Form at Active Hydrophobic Spots on the Luminal Aspect of Blood Vessels: Consequences for Decompression Illness in Diving and Possible Implications for Autoimmune Disease—An Overview

PubMed Central

Arieli, Ran

2017-01-01

Decompression illness (DCI) occurs following a reduction in ambient pressure. Decompression bubbles can expand and develop only from pre-existing gas micronuclei. The different hypotheses hitherto proposed regarding the nucleation and stabilization of gas micronuclei have never been validated. It is known that nanobubbles form spontaneously when a smooth hydrophobic surface is submerged in water containing dissolved gas. These nanobubbles may be the long sought-after gas micronuclei underlying decompression bubbles and DCI. We exposed hydrophobic and hydrophilic silicon wafers under water to hyperbaric pressure. After decompression, bubbles appeared on the hydrophobic but not the hydrophilic wafers. In a further series of experiments, we placed large ovine blood vessels in a cooled high pressure chamber at 1,000 kPa for about 20 h. Bubbles evolved at definite spots in all the types of blood vessels. These bubble-producing spots stained positive for lipids, and were henceforth termed “active hydrophobic spots” (AHS). The lung surfactant dipalmitoylphosphatidylcholine (DPPC), was found both in the plasma of the sheep and at the AHS. Bubbles detached from the blood vessel in pulsatile flow after reaching a mean diameter of ~1.0 mm. Bubble expansion was bi-phasic—a slow initiation phase which peaked 45 min after decompression, followed by fast diffusion-controlled growth. Many features of decompression from diving correlate with this finding of AHS on the blood vessels. (1) Variability between bubblers and non-bubblers. (2) An age-related effect and adaptation. (3) The increased risk of DCI on a second dive. (4) Symptoms of neurologic decompression sickness. (5) Preconditioning before a dive. (6) A bi-phasic mechanism of bubble expansion. (7) Increased bubble formation with depth. (8) Endothelial injury. (9) The presence of endothelial microparticles. Finally, constant contact between nanobubbles and plasma may result in distortion of proteins and their

Dose-Rate Effects in Breaking DNA Strands by Short Pulses of Extreme Ultraviolet Radiation.

PubMed

Vyšín, Luděk; Burian, Tomáš; Ukraintsev, Egor; Davídková, Marie; Grisham, Michael E; Heinbuch, Scott; Rocca, Jorge J; Juha, Libor

2018-05-01

In this study, we examined dose-rate effects on strand break formation in plasmid DNA induced by pulsed extreme ultraviolet (XUV) radiation. Dose delivered to the target molecule was controlled by attenuating the incident photon flux using aluminum filters as well as by changing the DNA/buffer-salt ratio in the irradiated sample. Irradiated samples were examined using agarose gel electrophoresis. Yields of single- and double-strand breaks (SSBs and DSBs) were determined as a function of the incident photon fluence. In addition, electrophoresis also revealed DNA cross-linking. Damaged DNA was inspected by means of atomic force microscopy (AFM). Both SSB and DSB yields decreased with dose rate increase. Quantum yields of SSBs at the highest photon fluence were comparable to yields of DSBs found after synchrotron irradiation. The average SSB/DSB ratio decreased only slightly at elevated dose rates. In conclusion, complex and/or clustered damages other than cross-links do not appear to be induced under the radiation conditions applied in this study.

Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial.

PubMed

Aufderheide, Tom P; Frascone, Ralph J; Wayne, Marvin A; Mahoney, Brian D; Swor, Robert A; Domeier, Robert M; Olinger, Michael L; Holcomb, Richard G; Tupper, David E; Yannopoulos, Demetris; Lurie, Keith G

2011-01-22

, disability ratings, and emotional-psychological statuses in both groups. The overall major adverse event rate did not differ between groups, but more patients had pulmonary oedema in the intervention group (94 [11%] of 840) than did controls (62 [7%] of 813; p=0·015). On the basis of our findings showing increased effectiveness and generalisability of the study intervention, active compression-decompression CPR with augmentation of negative intrathoracic pressure should be considered as an alternative to standard CPR to increase long-term survival after cardiac arrest. US National Institutes of Health grant R44-HL065851-03, Advanced Circulatory Systems. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of extremely low frequency electromagnetic fields on growth rate and morphology of bacteria.

PubMed

Inhan-Garip, Ayse; Aksu, Burak; Akan, Zafer; Akakin, Dilek; Ozaydin, A Nilufer; San, Tangul

2011-12-01

To determine the effect of extremely low frequency (<300 Hz) electromagnetic fields (ELF-EMF) on the growth rate of Gram-positive and Gram-negative bacteria and to determine any morphological changes that might have been caused by ELF-EMF. Six bacterial strains, three Gram-negative and three Gram-positive were subjected to 50 Hz, 0.5 mT ELF-EMF for 6 h. To determine growth rate after ELF-EMF application, bacteria exposed to ELF-EMF for 3 h were collected, transferred to fresh medium and cultured without field application for another 4 h. Growth-rate was determined by optical density (OD) measurements made every hour. Morphological changes were determined with Transmission electron microscopy (TEM) for two gram-negative and two gram-positive strains collected after 3 h of field application. A decrease in growth rate with respect to control samples was observed for all strains during ELF-EMF application. The decrease in growth-rate continued when exposed bacteria were cultured without field application. Significant ultrastructural changes were observed in all bacterial strains, which were seen to resemble the alterations caused by cationic peptides. This study shows that ELF-EMF induces a decrease in growth rate and morphological changes for both Gram-negative and Gram-positive bacteria.

MRI findings in patients with a history of failed prior microvascular decompression for hemifacial spasm: how to image and where to look.

PubMed

Hughes, M A; Branstetter, B F; Taylor, C T; Fakhran, S; Delfyett, W T; Frederickson, A M; Sekula, R F

2015-04-01

A minority of patients who undergo microvascular decompression for hemifacial spasm do not improve after the first operation. We sought to determine the most common locations of unaddressed neurovascular contact in patients with persistent or recurrent hemifacial spasm despite prior microvascular decompression. Eighteen patients with a history of a microvascular decompression presented with persistent hemifacial spasm. All patients underwent thin-section steady-state free precession MR imaging. Fourteen patients underwent repeat microvascular decompression at our institution. Images were evaluated for the following: the presence of persistent vascular compression of the facial nerve, type of culprit vessel (artery or vein), name of the culprit artery, segment of the nerve in contact with the vessel, and location of the point of contact relative to the existing surgical pledget. The imaging findings were compared with the operative findings. In 12 of the 18 patients (67%), persistent vascular compression was identified by imaging. In 11 of these 12 patients, the culprit vessel was an artery. Compression of the attached segment (along the ventral surface of the pons) was identified in most patients (58%, 7/12). The point of contact was proximal to the surgical pledget in most patients (83%, 10/12). The imaging interpretation was concordant with the surgical results regarding artery versus vein in 86% of cases and regarding the segment of the nerve contacted in 92%. In patients with persistent hemifacial spasm despite microvascular decompression, the unaddressed vascular compression is typically proximal to the previously placed pledget, usually along the attached segment of the nerve. Re-imaging with high-resolution T2-weighted MR imaging will usually identify the culprit vessel. © 2015 by American Journal of Neuroradiology.

Verification of an altitude decompression sickness prevention protocol for Shuttle operations utilizing a 10.s psi pressure stage

NASA Technical Reports Server (NTRS)

Waligora, J. M.; Horrigan, D. J., Jr.; Conkin, J.; Hadley, A. T., III

1984-01-01

Three test series involving 173-man tess were conducted to define and verify a pre-extravehicular activity (EVA) denitrogenation procedure that would provide acceptable protection against altitude decompression sickness while minimizing the required duration of oxygen (O2) prebreathe in the suit prior to EVA. The tests also addressed the safety, in terms of incidence of decompression sickness, of conducting EVA's on consecutive days rather than on alternate days. The tests were conducted in an altitude chamber, subjects were selected as representative of the astronaut population, and EVA periods were simulated by reducing the chamber pressure to suit pressure while the subjects breathed O2 with masks and worked at EVA representative work rates. A higher than anticipated incidence of both venous bubbles (55%) and symptoms (26%) was measured following all denitrogenation protocols in this test. For the most part, symptoms were very minor and stabilized, diminished, or disappeared in the six-hour tests. Instances of clear, possible, or potential systemic symptoms were encountered only after use of the unmodified 10.2 psi protocol and not after the modified 10.2 psi protocol, the 3.5-hour O2 prebreathed protocol, or the 4.0-hour O2 prebreathe protocol. The high incidence of symptoms is ascribed to the type and duration of exercise and the sensitivity of the reporting technique to minor symptoms. Repeated EVA exposures after only 17 hours did not increase symptom or bubble incidence.

Rule based artificial intelligence expert system for determination of upper extremity impairment rating.

PubMed

Lim, I; Walkup, R K; Vannier, M W

1993-04-01

Quantitative evaluation of upper extremity impairment, a percentage rating most often determined using a rule based procedure, has been implemented on a personal computer using an artificial intelligence, rule-based expert system (AI system). In this study, the rules given in Chapter 3 of the AMA Guides to the Evaluation of Permanent Impairment (Third Edition) were used to develop such an AI system for the Apple Macintosh. The program applies the rules from the Guides in a consistent and systematic fashion. It is faster and less error-prone than the manual method, and the results have a higher degree of precision, since intermediate values are not truncated.

Extreme nitrogen deposition can change methane oxidation rate in moist acidic tundra soil in Arctic regions

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, J.; Kang, H.

2017-12-01

Recently, extreme nitrogen(N) deposition events are observed in Arctic regions where over 90% of the annual N deposition occurred in just a few days. Since Arctic ecosystems are typically N-limited, input of extremely high amount of N could substantially affect ecosystem processes. CH4 is a potent greenhouse gas that has 25 times greater global warming potential than CO2 over a 100-year time frame. Ammonium is known as an inhibitor of methane oxidation and nitrate also shows inhibitory effect on it in temperate ecosystems. However, effects of N addition on Arctic ecosystems are still elusive. We conducted a lab-scale incubation experiment with moist acidic tundra (MAT) soil from Council, Alaska to investigate the effect of extreme N deposition events on methane oxidation. Zero point five % methane was added to the head space to determine the potential methane oxidation rate of MAT soil. Three treatments (NH4NO3-AN, (NH4)2SO4-AS, KNO3-PN) were used to compare effects of ammonium, nitrate and salts. All treatments were added in 3 levels: 10μg N gd.w-1(10), 50μg N gd.w-1(50) and 100μg N gd.w-1(100). AN10 and AN50 increased methane oxidation rate 1.7, 6% respectively. However, AN100 shows -8.5% of inhibitory effect. In AS added samples, all 3 concentrations (AN10, AN50, AN100) stimulated methane oxidation rate with 4.7, 8.9, 4%, respectively. On the contrary, PN50 (-9%) and PN100 (-59.5%) exhibited a significant inhibitory effect. We also analyzed the microbial gene abundance and community structures of methane oxidizing bacteria using a DNA-based fingerprinting method (T-RFLP) Our study results suggest that NH4+ can stimulate methane oxidation in Arctic MAT soil, while NO3- can inhibit methane oxidation significantly.

Assessment of routine elimination of postoperative nasogastric decompression after Roux-en-Y gastric bypass.

PubMed

Huerta, Sergio; Arteaga, James R; Sawicki, Mark P; Liu, Carson D; Livingston, Edward H

2002-11-01

Anastomotic disruption after surgical intervention is an infrequent complication, but may lead to severe morbidity and mortality when it occurs. Of the various gastric procedures, the Roux-en-Y gastric bypass (RYGB) has one of the highest risks for anastomotic leakage. Consequently, a nasogastric tube (NGT) is frequently placed when these operations are performed. Most studies examining the outcomes for patients without postoperative NGTs have been relatively small with groups of patients undergoing a variety of operations. Assessing the incidence of anastomotic leaks by routine elimination of postoperative NGTs requires a large number of patients. In this study, we assessed the safety and efficacy of routine elimination of NGTs in a large cohort of patients undergoing a single operation. We reviewed our experience with 1067 patients who underwent RYGB at the UCLA medical center. Fifty-six patients had NGTs routinely placed before the implementation of a standard protocol, which eliminated postoperative NGT decompression. The complication rate for the RYGB patient cohort with and without postoperative NGT was compared. We found no difference in the complication rates between the 2 groups (Fisher exact test; P =.21). Our findings suggest that routine placement of an NGT after RYGB is unnecessary.

Reconciling extreme branch length differences: decoupling time and rate through the evolutionary history of filmy ferns.

PubMed

Schuettpelz, Eric; Pryer, Kathleen M

2006-06-01

The rate of molecular evolution is not constant across the Tree of Life. Characterizing rate discrepancies and evaluating the relative roles of time and rate along branches through the past are both critical to a full understanding of evolutionary history. In this study, we explore the interactions of time and rate in filmy ferns (Hymenophyllaceae), a lineage with extreme branch length differences between the two major clades. We test for the presence of significant rate discrepancies within and between these clades, and we separate time and rate across the filmy fern phylogeny to simultaneously yield an evolutionary time scale of filmy fern diversification and reconstructions of ancestral rates of molecular evolution. Our results indicate that the branch length disparity observed between the major lineages of filmy ferns is indeed due to a significant difference in molecular evolutionary rate. The estimation of divergence times reveals that the timing of crown group diversification was not concurrent for the two lineages, and the reconstruction of ancestral rates of molecular evolution points to a substantial rate deceleration in one of the clades. Further analysis suggests that this may be due to a genome-wide deceleration in the rate of nucleotide substitution.

Is surgical case order associated with increased infection rate after spine surgery?

PubMed

Gruskay, Jordan; Kepler, Christopher; Smith, Jeremy; Radcliff, Kristen; Vaccaro, Alexander

2012-06-01

Retrospective database review. To determine whether surgical site infections are associated with case order in spinal surgery. Postoperative wound infection is the most common complication after spinal surgery, with incidence varying from 0.5% to 20%. The addition of instrumentation, use of preoperative prophylactic antibiotics, length of procedure, and intraoperative blood loss have all been found to influence infection rate. No previous study has attempted to correlate case order with infection risk after surgery. A total of 6666 spine surgery cases occurring between January 2005 and December 2009 were studied. Subjects were classified into 2 categories: fusion and decompression. Case order was determined, with each procedure labeled 1 to 5 depending on the number of previous cases in the room. Variables such as the American Society of Anesthesiologists score, number of operative levels, wound class, age, sex, and length of surgery were also tracked. A step-down binary regression was used to analyze each variable as a potential risk factor for infection. Decompression cases had a 2.4% incidence of infection. Longer surgical time and higher case order were found to be significant risk factors for lumbar decompressions. Fusion cases had a 3.5% incidence of infection. Posterior approach and revision cases were significant risk factors for infection in cervical cases. For lumbar fusion cases, longer surgical time, higher American Society of Anesthesiologists score, and older age were all significant risk factors for infection. Decompressive procedures performed later in the day carry a higher risk for postoperative infection. No similar trend was shown for fusion procedures. Our results identify potential modifiable risk factors contributing to infection rates in spinal procedures. Specific risk factors, although not defined in this study, might be related to contamination of the operating room, cross-contamination between health care providers during the course of

Survival after extreme left atrial hypertension and pulmonary hemorrhage in an infant supported with extracorporeal membrane oxygenation for refractory atrial flutter.

PubMed

Cisco, Michael J; Asija, Ritu; Dubin, Anne M; Perry, Stanton B; Hanley, Frank L; Roth, Stephen J

2011-05-01

We report here the survival of an infant who developed extreme left atrial hypertension and severe pulmonary hemorrhage while supported with extracorporeal membrane oxygenation for refractory atrial flutter. The patient recovered after decompression of the left heart and catheter ablation of the atrioventricular node. Lucile Packard Children's Hospital (Stanford, CA). Chart review. Recovery of lung function is possible despite systemic-level left atrial pressure resulting in pulmonary hemorrhage and complete solidification of lung parenchyma on gross inspection. Resolution of pulmonary hemorrhage despite anticoagulation while on extracorporeal membrane oxygenation can occur after relief of left atrial hypertension.

Anterior versus lateral needle decompression of tension pneumothorax: comparison by computed tomography chest wall measurement.

PubMed

Sanchez, Leon D; Straszewski, Shannon; Saghir, Amina; Khan, Atif; Horn, Erin; Fischer, Christopher; Khosa, Faisal; Camacho, Marc A

2011-10-01

Recent research describes failed needle decompression in the anterior position. It has been hypothesized that a lateral approach may be more successful. The aim of this study was to identify the optimal site for needle decompression. A retrospective study was conducted of emergency department (ED) patients who underwent computed tomography (CT) of the chest as part of their evaluation for blunt trauma. A convenience sample of 159 patients was formed by reviewing consecutive scans of eligible patients. Six measurements from the skin surface to the pleural surface were made for each patient: anterior second intercostal space, lateral fourth intercostal space, and lateral fifth intercostal space on the left and right sides. The distance from skin to pleura at the anterior second intercostal space averaged 46.3 mm on the right and 45.2 mm on the left. The distance at the midaxillary line in the fourth intercostal space was 63.7 mm on the right and 62.1 mm on the left. In the fifth intercostal space the distance was 53.8 mm on the right and 52.9 mm on the left. The distance of the anterior approach was statistically less when compared to both intercostal spaces (p < 0.01). With commonly available angiocatheters, the lateral approach is less likely to be successful than the anterior approach. The anterior approach may fail in many patients as well. Longer angiocatheters may increase the chances of decompression, but would also carry a higher risk of damage to surrounding vital structures. © 2011 by the Society for Academic Emergency Medicine.

Baastrup's Disease Is Associated with Recurrent of Sciatica after Posterior Lumbar Spinal Decompressions Utilizing Floating Spinous Process Procedures

PubMed Central

Mannoji, Chikato; Murakami, Masazumi; Kinoshita, Tomoaki; Hirayama, Jiro; Miyashita, Tomohiro; Eguchi, Yawara; Yamazaki, Masashi; Suzuki, Takane; Aramomi, Masaaki; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Furuya, Takeo

2016-01-01

Study Design Retrospective case-control study. Purpose To determine whether kissing spine is a risk factor for recurrence of sciatica after lumbar posterior decompression using a spinous process floating approach. Overview of Literature Kissing spine is defined by apposition and sclerotic change of the facing spinous processes as shown in X-ray images, and is often accompanied by marked disc degeneration and decrement of disc height. If kissing spine significantly contributes to weight bearing and the stability of the lumbar spine, trauma to the spinous process might induce a breakdown of lumbar spine stability after posterior decompression surgery in cases of kissing spine. Methods The present study included 161 patients who had undergone posterior decompression surgery for lumbar canal stenosis using a spinous process floating approaches. We defined recurrence of sciatica as that resolved after initial surgery and then recurred. Kissing spine was defined as sclerotic change and the apposition of the spinous process in a plain radiogram. Preoperative foraminal stenosis was determined by the decrease of perineural fat intensity detected by parasagittal T1-weighted magnetic resonance imaging. Preoperative percentage slip, segmental range of motion, and segmental scoliosis were analyzed in preoperative radiographs. Univariate analysis followed by stepwise logistic regression analysis determined factors independently associated with recurrence of sciatica. Results Stepwise logistic regression revealed kissing spine (p=0.024; odds ratio, 3.80) and foraminal stenosis (p<0.01; odds ratio, 17.89) as independent risk factors for the recurrence of sciatica after posterior lumbar spinal decompression with spinous process floating procedures for lumbar spinal canal stenosis. Conclusions When a patient shows kissing spine and concomitant subclinical foraminal stenosis at the affected level, we should sufficiently discuss the selection of an appropriate surgical procedure. PMID

Evaluating the risk of decompression sickness for a yo-yo dive using a rat model.

PubMed

Ofir, Dror; Yanir, Yoav; Abramovich, Amir; Bar, Ronen; Arieli, Yehuda

2016-01-01

The frequent ascents made during yo-yo diving may contribute to gas bubble clearance but paradoxically may also increase the risk of central nervous system decompression illness (DCI). We evaluated the risk of DCI due to yo-yo dives with very short surface intervals, using a controlled animal model. Dives were conducted on air to a depth of 90 meters (10 atmospheres absolute) for 32 minutes of bottom time, at a descent/ascent rate of 10 meters/ minute. Sprague-Dawley rats weighing ~ 300 grams were divided randomly into three groups. Group A performed a square dive protocol without any surface intervals, Group B conducted a protocol that included two surface intervals during the dive, and Group C performed a protocol with three surface intervals. Ascent/descent rate for surface intervals, each lasting one minute, was also 10 meters/minute. Manifestations of DCI were observed in 13 of 16 animals in Group A (81.3%), six of 12 in Group B (58.3%), and two of 12 in Group C (16.7%). Mortality rates were similar in all groups. Surface intervals during dives breathing air significantly reduced DCI risk in the rat. Further studies are required using a larger animal model to reinforce the results of the present investigation.

Application of small intestine decompression combined with oral feeding in middle and late period of malignant small bowel obstruction.

PubMed

Li, Dechun; Du, Hongtao; Shao, Guoqing; Guo, Yongtuan; Lu, Wan; Li, Ruihong

2017-07-01

The application value of small intestine decompression combined with oral feeding in the middle and late period of malignant small bowel obstruction was examined. A total of 22 patients with advanced malignant small bowel obstruction were included in the present study. An ileus tube was inserted via the nose under fluoroscopy into the obstructed small intestine of each patient. At the same time, the insertion depth the of the catheter was adjusted. When the catheter was blocked, small bowel selective angiography was performed to determine the location and cause of the obstruction and the extent of the obstruction, and to determine the length of the small intestine in the site of obstruction, and to select the variety and tolerance of enteral nutrition. We observed the decompression tube flow and ease of intestinal obstruction. In total, 20 patients were treated with oral enteral nutrition after abdominal distension, and 22 cases were treated by the nose to observe the drainage and the relief of intestinal obstruction. The distal end of the catheter was placed in a predetermined position. The symptoms of intestinal obstruction were relieved 1-4 days after decompression. The 22 patients with selective angiography of the small intestine showed positive X-ray signs: 18 patients with oral enteral nutrition therapy had improved the nutritional situation 2 weeks later. In 12 cases, where there was anal defecation exhaust, 2 had transient removal of intestinal obstruction catheter. In conclusion, this comprehensive treatment based on small intestine decompression combined with enteral nutrition is expected to become a new therapeutic approach and method for the treatment of patients with advanced tumor small bowel obstruction.

Surgical Decompression for Chiari Malformation Type I: An Age-Based Outcomes Study Based on the Chicago Chiari Outcome Scale.

PubMed

Gilmer, Holly S; Xi, Mengqiao; Young, Sonja H

2017-11-01

There is currently inadequate evidence on the efficacy of surgical decompression for Chiari malformation type I (CM1) in different age groups of patients. In this study, we compared postoperative outcomes across 3 different age groups using the Chicago Chiari Outcome Scale (CCOS). A total of 144 patients who underwent Chiari decompression at our institution between 2008 and 2014 were divided into 3 groups: group A, children age 0-18 years; group B, younger adults age 19-40 years; and group C, older adults, age 41+ years. Patient outcomes were assigned a numerical value based on the CCOS and subjected to statistical analysis. Direct comparisons were made across the 3 age groups. The mean overall score was 14.0 over a mean follow-up of 27.2 months. All 3 groups demonstrated clinical improvement following Chiari decompression; however, group A demonstrated significantly better postoperative improvements than groups B and C in total CCOS scores (7.8% and 12.2%, respectively; P < 0.001) and all the component scores except complications. Group B was not significantly different from group C in total score or any of the component scores. There was a logarithmic relationship between age and outcome (R 2  = 0.64), in which the outcome scores experienced an initial decline with increasing age but leveled off by early adulthood. A direct comparison among the age groups revealed a negative age effect on surgical decompression outcomes in CM1 patients. Children performed significantly better than younger and older adults. This finding supports early surgical intervention for symptomatic pediatric patients to achieve long-term surgical benefit. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Changes of cervical dorsal root ganglia induced by compression injury and decompression procedure: a novel rat model of cervical radiculoneuropathy.

PubMed

Tang, Zhan-Ying; Shu, Bing; Cui, Xue-Jun; Zhou, Chong-Jian; Shi, Qi; Holz, Jonathan; Wang, Yong-Jun

2009-02-11

Our study aimed to establish a model of compression injury of cervical dorsal root ganglia (DRG) in the rat and to investigate the pathological changes following compression injury and decompression procedures. Thirty rats were divided into three groups: control group receiving sham surgery, compression group undergoing surgery to place a micro-silica gel on C6 DRG, and decompression group with subsequent decompression procedure. The samples harvested from the different groups were examined with light microscopy, ultrastructural analysis, and horseradish peroxidase (HRP) retrograde tracing techniques. Apoptosis of DRG neurons was demonstrated with TUNEL staining. Changes in PGE2 and PLA2 in DRG neurons were detected with enzyme-linked immunosorbent assay (ELISA). Local expression of vascular endothelial growth factor (VEGF) was monitored with immunohistochemistry. DRG neurons in the compression group became swollen with vacuolar changes in cytoplasm. Decompression procedure partially ameliorated the resultant compression pathology. Ultrastructural examination showed a large number of swollen vacuoles, demyelinated nerve root fibers, absence of Schwann cells, and proliferation in the surrounding connective tissues in the compression group. Compared to the control group, the compression group showed a significant decrease in the number of the HRP-labeled cells and a significant increase in levels of PGE2 and PLA2, in the expression of VEGF protein, and in the number of apoptotic DRG neurons. These findings demonstrate that compression results in local inflammation, followed by increased apoptosis and upregulation of VEGF. We conclude that such a model provides a tool to study the pathogenesis and treatment of cervical radiculoneuropathy.

Changes in peripapillary blood vessel density in Graves' orbitopathy after orbital decompression surgery as measured by optical coherence tomography angiography.

PubMed

Lewis, Kyle T; Bullock, John R; Drumright, Ryan T; Olsen, Matthew J; Penman, Alan D

2018-03-08

The purpose is to evaluate the utility of optical coherence tomography (OCT) angiography in the evaluation of Graves' orbitopathy (GO) and response to orbital decompression in patients with and without dysthyroid optic neuropathy (DON). This was a single-center, prospective case series in a cohort of 12 patients (24 orbits) with GO and ±DON, (6 orbits) who underwent bilateral orbital decompression. All patients underwent pre- and postoperative OCT angiography of the peripapillary area. Vessel density indices were calculated in a 4.5 mm × 4.5 mm ellipsoid centered on the optic disk using split-spectrum amplitude decorrelation angiography algorithm, producing the vessel density measurements. Mean change in vessel density indices was compared between pre- and postoperative sessions and between patients with and without DON. Patient 1, a 34-year-old male with GO and unilateral DON OD, showed a significant reduction in blood vessel density indices oculus dexter (OD) (DON eye) after decompression while a more modest reduction was found oculus sinister (OS) with the greatest change noted intrapapillary. Patient 2, a 50-year-old male with DON OU, showed worsening neuropathy following decompression OD that was confirmed by angiographic density indices. Patient 3, a 55-year-female with DON, showed a reduction in blood vessel density OD and increased density OS. Patients without DON showed overall less impressive changes in indices as compared to those with DON. Using OCT angiography, response to surgical treatment in GO orbits, more so in orbits with DON, can be demonstrated and quantified using vessel density indices with reproducibility.

Tracking performance with two breathing oxygen concentrations after high altitude rapid decompression

NASA Technical Reports Server (NTRS)

Nesthus, Thomas E.; Schiflett, Samuel G.; Oakley, Carolyn J.

1992-01-01

Current military aircraft Liquid Oxygen (LOX) systems supply 99.5 pct. gaseous Aviator's Breathing Oxygen (ABO) to aircrew. Newer Molecular Sieve Oxygen Generation Systems (MSOGS) supply breathing gas concentration of 93 to 95 pct. O2. The margin is compared of hypoxia protection afforded by ABO and MSOGS breathing gas after a 5 psi differential rapid decompression (RD) in a hypobaric research chamber. The barometric pressures equivalent to the altitudes of 46000, 52000, 56000, and 60000 ft were achieved from respective base altitudes in 1 to 1.5 s decompressions. During each exposure, subjects remained at the simulated peak altitude breathing either 100 or 94 pct. O2 with positive pressure for 60 s, followed by a rapid descent to 40000 ft. Subjects used the Tactical Life Support System (TLSS) for high altitude protection. Subcritical tracking task performance on the Performance Evaluation Device (PED) provided psychomotor test measures. Overall tracking task performance results showed no differences between the MSOGS breathing O2 concentration of 94 pct. and ABO. Significance RMS error differences were found between the ground level and base altitude trials compared to peak altitude trials. The high positive breathing pressures occurring at the peak altitudes explained the differences.

Decompression illness secondary to occupational diving: recommended management based current legistation and practice in Malaysia.

PubMed

Rozali, A; Khairuddin, H; Sherina, M S; Zin, B Mohd; Sulaiman, A

2008-06-01

Occupational divers are exposed to hazards which contribute to the risk of developing decompression illnesses (DCI). DCI consists of Type I decompression sickness (DCS), Type II DCS and arterial gas embolism (AGE), developed from formation of bubbles in the tissues or circulation as a result of inadequate elimination of inert gas (nitrogen) after a dive. In Malaysia, DCI is one of the significant contributions to mortality and permanent residual morbidity in diving accidents. This is a case of a diver who suffered from Type II DCS with neurological complications due to an occupational diving activity. This article mentions the clinical management of the case and makes several recommendations based on current legislations and practise implemented in Malaysia in order to educate medical and health practitioners on the current management of DCI from the occupational perspective. By following these recommendations, hopefully diving accidents mainly DCI and its sequalae among occupational divers can be minimized and prevented, while divers who become injured receive the proper compensation for their disabilities.

Case Descriptions and Observations About Cutis Marmorata From Hypobaric Decompressions

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Pilmanis, Andrew A.; Webb, James T.

2002-01-01

There is disagreement about the pathophysiology, classification, and treatment of cutis marmorata (CM), so there is disagreement about the disposition and medical status of a person that had CM. CM is rare, associated with stressful decompressions, and may be associated with serious signs and symptoms of decompression sickness (DCS). CM presents as purple or bluish-red skin mottling, often in the pectoral region, shoulders, chest, or upper abdomen. It is unethical to induce CM in humans so all information comes from retrospective analysis of case reports, or from animal models. A literature search, seven recent case reports from the Johnson Space Center and Brooks Air Force Base Hypobaric DCS Databases, interviews with DCS treatment experts, and responses to surveys provided the factual information used to arrive at our conclusions and recommendations. The "weight of evidence" indicates that CM is a local, not centrally mediated or systemic response to bubbles. It is unclear whether obstruction of arterial or venous blood flow is the primary insult since the lesion is reported under either condition. Any neurological or cardiovascular involvements are coincidental, developing along the same time course. The skin could be the source of the bubbles due to its mass, the associated layer of fat, and the variable nature of skin blood flow. CM should not be categorized as Type II DCS, should be included with other skin manifestations in a category called cutaneous DCS, and hyperbaric treatment is only needed if ground level oxygen is ineffective in the case of altitude-induced CM.

Core decompression of the femoral head for osteonecrosis using percutaneous multiple small-diameter drilling.

PubMed

Mont, Michael A; Ragland, Phillip S; Etienne, Gracia

2004-12-01

Osteonecrosis is a disease with a wide ranging etiology and poorly understood pathogenesis seen commonly in young patients. Core decompression has historically been used in patients with small-sized or medium-sized precollapse lesions in an attempt to forestall disease progression. Typically, an 8-10 mm wide cannula trephine is used to do this procedure. The authors report on a new technique using multiple small drillings with a 3-mm Steinman pin to effectuate the core decompression. In this report, there were 32 of 45 hips (71%; 35 patients) with a successful clinical result at a mean followup of 2 years (range, 20-39 months). Twenty four of 30 Stage I hips (80%; 23 patients) had successful outcomes compared with 8 of 15 Stage II hips (57%; 12 patients) with no surgical complications occurring with this technique. This procedure is technically straightforward and led to minimal morbidity with no surgical complications. It may be effective in delaying the need for total hip arthroplasty in young patients with early (precollapse) stages of femoral head osteonecrosis.

Relationship between attrition and neurodevelopmental impairment rates in extremely preterm infants at 18 to 24 months: a systematic review.

PubMed

Guillén, Ursula; DeMauro, Sara; Ma, Li; Zupancic, John; Roberts, Robin; Schmidt, Barbara; Kirpalani, Haresh

2012-02-01

To assess the effect of loss to follow-up rates at 18 to 24 months on neurodevelopmental outcome statistics for infants of less than 1000 g birth weight or less than 28 weeks' gestational age. MEDLINE, EMBASE, PubMed, and Cochrane Library databases (January 1, 2000, to June 30, 2010). We searched for studies reporting outcomes of infants of less than 1000 g birth weight or less than 28 weeks' gestational age who were born after 1990. Eligible articles had to report the primary outcome and follow-up rates at 18 to 24 months. Our primary composite outcome of neurodevelopmental impairment (NDI) was any of a mental developmental quotient 2 SDs below the mean, using the Bayley Scales of Infant Development II; cerebral palsy; visual impairment; or significant hearing impairment. Of 43 publications describing outcomes at 18 to 24 months, 20 provided rates of follow-up, describing a total of 34,185 infants. The NDI rates ranged between 12.4% and 57.5%. Follow-up rates ranged between 71.6% and 100%. Higher rates of NDI were significantly correlated with greater loss to follow-up (r(2) = 0.38, P = .007). Higher rates of both NDI and loss to follow-up were seen in the United States compared with Canada, the United Kingdom, Finland, Denmark, Austria, Germany, and Australia (r(2) = 0.70, P = .001). Ascertainment bias may overestimate NDI in extremely low-birth-weight or extremely low-gestational-age survivors at 18 to 24 months. Alternatively, the characteristics of different populations and health systems may contribute to higher rates of attrition and higher rates of NDI.

[Decompression problems in diving in mountain lakes].

PubMed

Bühlmann, A A

1989-08-01

The relationship between tolerated high-pressure tissue nitrogen and ambient pressure is practically linear. The tolerated nitrogen high pressure decreases at altitude, as the ambient pressure is lower. Additionally, tissues with short nitrogen half-times have a higher tolerance than tissues which retain nitrogen for longer duration. For the purpose of determining safe decompression routines, the human body can be regarded as consisting of 16 compartments with half-times from 4 to 635 minutes for nitrogen. The coefficients for calculation of the tolerated nitrogen-high pressure in the tissues can be deduced directly from the half-times for nitrogen. We show as application the results of 573 simulated air dives in the pressure-chamber and 544 real dives in mountain lakes in Switzerland (1400-2600 m above sea level) and in Lake Titicaca (3800 m above sea level). They are in accordance with the computed limits of tolerance.

Evidence-Based Approach to the Analysis of Serious Decompression Sickness with Application to EVA Astronauts

NASA Technical Reports Server (NTRS)

Conkin, Johnny

2001-01-01

It is important to understand the risk of serious hypobaric decompression sickness (DCS) in order to develop procedures and treatment responses to mitigate the risk. Since it is not ethical to conduct prospective tests about serious DCS with humans, the necessary information was gathered from 73 published reports. We hypothesize that a 4-hr 100% oxygen (O2) prebreathe results in a very low risk of serious DCS, and test this through analysis. We evaluated 258 tests containing information from 79,366 exposures in attitude chambers. Serious DCS was documented in 918 men during the tests. Serious DCS are signs and symptoms broadly classified as Type II DCS. A risk function analysis with maximum likelihood optimization was performed to identify significant explanatory variables, and to create a predictive model for the probability of serious DCS [P(serious DCS)]. Useful variables were Tissue Ratio, the planned time spent at altitude (T(sub alt)), and whether or not repetitive exercise was performed at altitude. Tissue Ratio is P1N2/P2, where P1N2 is calculated nitrogen (N2) pressure in a compartment with a 180-min half-time for N2 pressure just before ascent, and P2 is ambient pressure after ascent. A prebreathe and decompression profile Shuttle astronauts use for extravehicular activity (EVA) includes a 4-hr prebreathe with 100% O2, an ascent to P2 = 4.3 lb per sq. in. absolute, and a T(sub alt) = 6 hr. The P(serious DCS) is: 0.0014 (0.00096 - 0.00196, 95% confidence interval) with exercise and 0.00025 (0.00016 - 0.00035) without exercise. Given 100 Shuttle EVAs to date and no report of serious DCS, the true risk is less than 0.03 with 95% confidence (Binomial Theorem). It is problematic to estimate the risk of serious DCS since it appears infrequently, even if the estimate is based on thousands of altitude chamber exposures. The true risk to astronauts may lie between the extremes of the confidence intervals (0.00016 - 0.00196) since the contribution of other factors

[Clinical study on spinal cord decompression combined with traditional Chinese medicine for the treatment of cervical spondylotic myelopathy].

PubMed

Yang, Feng; Tan, Ming-Sheng; Yi, Ping; Tang, Xiang-Sheng; Hao, Qing-Ying; Qi, Ying-Na

2018-01-25

To compare the clinical effect between spinal card decompression combined with traditional Chinese medicine and simple spinal card decompression for cervical spondylotic myelopathy. From June 2012 to June 2015, 73 patients with cervical spondylotic myelopathy were treated, including 42 males and 31 females, aged from 29 to 73 years old with a mean of 50.9 years old. The patients were divided into the simple operation group (34 cases) and the operation combined with traditional Chinese medicine group(39 cases) according to the idea of themselves. The anterior discectomy or subtotal corpectomy with internal fixation or posterior simple open-door decompression with lateral mass screw fixation were performed in the patients. Among them, 39 cases were treated with traditional Chinese medicine after surgery. The Japanese orthopedic association (JOA) score of spinal cord function, the improvement rate of neural function, the neck dysfunction index (NDI) score and the governor vessel stasis syndrome score were compared between two groups preoperative and postoperative 1 week, 1 month and the final follow-up respectively. The internal fixation and the condition of spinal cord decompression were observed by CT, MRI and X-rays before and after operation. All the operations were successful, no injuries such as dura mater, spinal cord and nerve root were found. All the wounds were healed without infection except one patient had a superficial infection. It was solved after intermittent debridement and anti-infective therapy. Hematoma occurred in 1 case, complicated with spinal cord compression, caused incomplete paralysis, and promptly performed the re-operation to remove the hematoma without any obvious sequelae. All the patients were followed up from 12 to 24 months, (14.6±0.8) months for simple operation group and (13.5±0.7) months for operation combined with traditional Chinese medicine group, and there was no significant difference( P >0.05). The scores of JOA, NDI and

2014 Decompression Sickness/Extravehicular Activity Risks Standing Review Panel

NASA Technical Reports Server (NTRS)

Steinberg, Susan; Mahon, Richard; Klaus, David; Neuman, Tom; Pilmanis, Andrew; Regis, David

2014-01-01

The 2014 Decompression Sickness (DCS)/Extravehicular Activity (EVA) Risks Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on November 4 - 5, 2014. The SRP reviewed the Research Plans for The Risk of Decompression Sickness and the Risk of Injury and Compromised Performance due to EVA Operations, as well as the Evidence Reports for both of these Risks. The SRP found that the NASA DCS/EVA team did an excellent job of presenting their research plans. The SRP considers it critical that NASA proceeds with the high priority tasks identified in this report (DCS1, DCS3, DCS5). The highest priority is to determine the acceptable DCS and hypoxia risk associated with the planned human exploration beyond low Earth orbit. The risk of DCS is highly dependent upon the pressure within the exploration vehicle. If slightly more hypoxia is permitted then (even with the same percentage of oxygen) the pressure within the exploration vehicle can be lowered thus further mitigating the risk of DCS. The second highest priority is to test and validate the recommended 8.2psi/34% O2 atmosphere. Development of procedures and equipment for human exploration missions are very limited until the results of this testing are completed. The SRP also suggests that DCS7 be separated into two Gaps. Gap DCS7 should deal with DCS treatment while a new Gap should be created to deal with the long-term effects of DCS. The SRP also encourages NASA to increase collaboration with other organizations and pool resources where possible. The current NASA DCS/EVA team has the extensive expertise and a wealth of knowledge in this area. The SRP suggests that increased manpower for this team would be highly productive.

A no-decompression air dive and ultrasound lung comets.

PubMed

Dujic, Zeljko; Marinovic, Jasna; Obad, Ante; Ivancev, Vladimir; Breskovic, Toni; Jovovic, Pavle; Ljubkovic, Marko

2011-01-01

Increased accumulation of extravascular lung water after repetitive deep trimix dives was recently reported. This effect was evident 40 min post-dive, but in subsequent studies most signs of this lung congestion were not evident 2-3 h post-dive, indicating no major negative effects on respiratory gas exchange following deep dives. Whether this response is unique for trimix dives or also occurs in more frequent air dives is presently unknown. A single no-decompression field dive to 33 m with 20 min bottom time was performed by 12 male divers. Multiple ultrasound lung comets (ULC), bubble grade (BG), and single-breath lung diffusing capacity (DLCO) measurements were made before and up to 120 min after the dive. Median BG was rather high with maximal values observed at 40 min post-dive [median 4 (4-4)]. Arterialization of bubbles from the venous side was observed only in one diver lasting up to 60 min post-dive. Despite high BG, no DCS symptoms were noted. DLCO and ULC were unchanged after the dive at any time point (DLCO(corr) was 33.6 +/- 1.9 ml x min(-1) mmHg(-1) pre-dive, 32.7 +/- 3.8 ml x min(-1) x mmHg(-1) at 60 min post-dive, and 33.2 +/- 5.3 ml x min(-1) x mmHg(-1) at 120 min post-dive; ULC count was 4.1 +/- 1.9 pre-dive, 4.9 +/- 3.3 at 20 min post-dive, and 3.3 +/- 1.9 at 60 min post-dive. These preliminary findings show no evidence of increased accumulation of extravascular lung water in male divers after a single no-decompression air dive at the limits of accepted Norwegian diving tables.

The clinical study of percutaneous disc decompression of treating herniation of cervical disc with Nd:YAG laser

NASA Astrophysics Data System (ADS)

Zhang, Dianxue; Cheng, Hefu; Wang, Jindong

2005-07-01

Objective: The possibility of PLDD (percutaneous laser disc decompression) and an ideal non-operative method which is long everlasting effect for PLDD was investigated. Methods: 159 patients of Cervical Disc Herniation with PLDD were studied. All the herniated discs were irradiated with 10­15J/S Nd:YAG laser quantum through optical-fiber under the supervision of C-arm X-ray. Results: All the patients were followed and reexamined CT or MRI after one to six months of PLDD. The result of cured (67.92%), excellent (24.53%), moderation (5.66%), non-effect (1.88%) was got. The excellent rate was 88.24%. The effective rate was 97.65%. Non-effective rate was 2.35%. Conclusion: When irradiated with Nd:YAG laser, the nucleus pulposus was vapouring, charring and coagulating. The volume and inner-pressure of the disc decreased. So the symptoms and signs improved. The main value of this methods were micro-damage, non-operation, no bleeding, no bone injury, good therapy effect, quick recovery, lesser pain, safety and excellent long everlasting effect. It is an ideal non-operative method of treating PLDD.

Long-term outcome and prognostic factors after C2 ganglion decompression in 68 consecutive patients with intractable occipital neuralgia.

PubMed

Choi, Kyu-Sun; Ko, Yong; Kim, Young-Soo; Yi, Hyeong-Joong

2015-01-01

Occipital neuralgia is a rare cause of severe headache characterized by paroxysmal shooting or stabbing pain in the distribution of the greater occipital or lesser occipital nerve. In cases of intractable occipital neuralgia, a definite cause has not been uncovered, so various types of treatment have been applied. The aim of this study is to evaluate the prognostic factors, safety, and long-term clinical efficacy of second cervical (C2) ganglion decompression for intractable occipital neuralgia. Retrospective analysis was performed in 68 patients with medically refractory occipital neuralgia who underwent C2 ganglion decompression. Factors based on patients' demography, pre- and postoperative headache severity/characteristics, medication use, and postoperative complications were investigated. Therapeutic success was defined as pain relief by at least 50 % without ongoing medication. The visual analog scale (VAS) score was significantly reduced between the preoperative and most recent follow-up period. One year later, excellent or good results were achieved in 57 patients (83.9 %), but poor in 11 patients (16.1 %). The long-term outcome after 5 years was only slightly less than the 1-year outcome; 47 of the 68 patients (69.1 %) obtained therapeutic success. Longer duration of headache (over 13 years; p = 0.029) and presence of retro-orbital/frontal radiation (p = 0.040) were significantly associated with poor prognosis. In the current study, C2 ganglion decompression provided durable, adequate pain relief with minimal complications in patients suffering from intractable occipital neuralgia. Due to the minimally invasive and nondestructive nature of this surgical procedure, C2 ganglion decompression is recommended as an initial surgical treatment option for intractable occipital neuralgia before attempting occipital nerve stimulation. However, further study is required to manage the pain recurrence associated with longstanding nerve injury.

Urgent Optic Nerve Decompression via an Endoscopic Endonasal Transsphenoidal Approach for Craniopharyngioma in a 12-Month-Old Infant: A Case Report.

PubMed

Shibata, Teishiki; Tanikawa, Motoki; Sakata, Tomohiro; Mase, Mitsuhito

2018-01-01

Craniopharyngiomas are benign tumors and account for approximately 5.6-13% of all intracranial tumors in children. Diagnosis of pediatric craniopharyngioma is often delayed until the tumor becomes relatively large and manifests severe visual and/or endocrine disturbance. Endoscopic endonasal approaches have recently been introduced to surgery for craniopharyngioma. These techniques, however, have rarely been utilized in patients affected with craniopharyngioma as young as 1 year old. This report documents a 12-month-old male infant with sellar craniopharyngioma who presented with acute total vision loss. To increase the chances of visual recovery, an endoscopic endonasal optic nerve decompression was performed as an urgent procedure. After decompression, which resulted in improvement of his visual disturbance, gross total resection of the tumor was undertaken through an anterior interhemispheric approach at a later date. Tumor mass reduction through an endoscopic endonasal transsphenoidal approach followed by secondary radical total resection under craniotomy was considered to be useful in cases such as this when urgent optic nerve decompression is required. © 2018 S. Karger AG, Basel.

Different effect of l-NAME treatment on susceptibility to decompression sickness in male and female rats.

PubMed

Mazur, Aleksandra; Buzzacott, Peter; Lambrechts, Kate; Wang, Qiong; Belhomme, Marc; Theron, Michael; Popov, Georgi; Distefano, Giovanni; Guerrero, Francois

2014-11-01

Vascular bubble formation results from supersaturation during inadequate decompression contributes to endothelial injuries, which form the basis for the development of decompression sickness (DCS). Risk factors for DCS include increased age, weight-fat mass, decreased maximal oxygen uptake, chronic diseases, dehydration, and nitric oxide (NO) bioavailability. Production of NO is often affected by diving and its expression-activity varies between the genders. Little is known about the influence of sex on the risk of DCS. To study this relationship we used an animal model of Nω-nitro-l-arginine methyl ester (l-NAME) to induce decreased NO production. Male and female rats with diverse ages and weights were divided into 2 groups: treated with l-NAME (in tap water; 0.05 mg·mL(-1) for 7 days) and a control group. To control the distribution of nitrogen among tissues, 2 different compression-decompression protocols were used. Results showed that l-NAME was significantly associated with increased DCS in female rats (p = 0.039) only. Weight was significant for both sexes (p = 0.01). The protocol with the highest estimated tissue pressures in the slower compartments was 2.6 times more likely to produce DCS than the protocol with the highest estimated tissue pressures in faster compartments. The outcome of this study had significantly different susceptibility to DCS after l-NAME treatment between the sexes, while l-NAME per se had no effect on the likelihood of DCS. The analysis also showed that for the appearance of DCS, the most significant factors were type of protocol and weight.

Analysis of the individual risk of altitude decompression sickness under repeated exposures

NASA Technical Reports Server (NTRS)

Kumar, K. Vasantha; Horrigan, David J.; Waligora, James M.; Gilbert, John H.

1991-01-01

In a case-control study, researchers examined the risk of decompression sickness (DCS) in individual subjects with higher number of exposures. Of the 126 subjects, 42 showed one or more episodes of DCS. Examination of the exposure-DCS relationship by odds ratio showed a linear relationship. Stratification analysis showed that sex, tissue ratio, and the presence of Doppler microbubbles were cofounders of this risk. A higher number of exposures increased the risk of DCS in this analysis.

The Pathophysiology of Decompression Sickness and the Effects of Doppler Detectable Bubbles.

DTIC Science & Technology

1980-12-18

Doppler Ultrasound and a calibrated 6 1 Venous Gas Embol i Scale. C. Electronic Counting of Doppler Bubble Signals 72 £ III. Pulmonary Embolism Studies...IA. Background 75 B. Right Ventricular Systolic Pressure following Gas 81 Embolization and Venous Gas Phase Content IC. Effects of Pulmonary Gas... Embolism on the Development 9 of Limb-Bend Decompression Sickness 1 IV. Gas Phase Formation in Highly Perfused Tissues IA. Renal 9 B. Cerebral 9 1 I I V

The use of portable 2D echocardiography and 'frame-based' bubble counting as a tool to evaluate diving decompression stress.

PubMed

Germonpré, Peter; Papadopoulou, Virginie; Hemelryck, Walter; Obeid, Georges; Lafère, Pierre; Eckersley, Robert J; Tang, Meng-Xing; Balestra, Costantino

2014-03-01

'Decompression stress' is commonly evaluated by scoring circulating bubble numbers post dive using Doppler or cardiac echography. This information may be used to develop safer decompression algorithms, assuming that the lower the numbers of venous gas emboli (VGE) observed post dive, the lower the statistical risk of decompression sickness (DCS). Current echocardiographic evaluation of VGE, using the Eftedal and Brubakk method, has some disadvantages as it is less well suited for large-scale evaluation of recreational diving profiles. We propose and validate a new 'frame-based' VGE-counting method which offers a continuous scale of measurement. Nine 'raters' of varying familiarity with echocardiography were asked to grade 20 echocardiograph recordings using both the Eftedal and Brubakk grading and the new 'frame-based' counting method. They were also asked to count the number of bubbles in 50 still-frame images, some of which were randomly repeated. A Wilcoxon Spearman ρ calculation was used to assess test-retest reliability of each rater for the repeated still frames. For the video images, weighted kappa statistics, with linear and quadratic weightings, were calculated to measure agreement between raters for the Eftedal and Brubakk method. Bland-Altman plots and intra-class correlation coefficients were used to measure agreement between raters for the frame-based counting method. Frame-based counting showed a better inter-rater agreement than the Eftedal and Brubakk grading, even with relatively inexperienced assessors, and has good intra- and inter-rater reliability. Frame-based bubble counting could be used to evaluate post-dive decompression stress, and offers possibilities for computer-automated algorithms to allow near-real-time counting.

Adding Expansile Duraplasty to Posterior Fossa Decompression May Restore Cervical Range of Motion in Grade 3 Chiari Malformation Type 1 Patients.

PubMed

Yilmaz, Adem; Urgun, Kamran; Aoun, Salah G; Colak, Ibrahim; Yilmaz, Ilhan; Altas, Kadir; Musluman, Murat

2017-02-01

Few studies have assessed the effect of Chiari malformation type 1 (CM-1) surgical decompression on cervical lordosis and range of motion (ROM). We aimed to assess the effect of expansile duraplasty on postoperative cervical mobility and spinal stability. This was a single-center retrospective review of prospectively collected data. Patients were included if they underwent surgical treatment for symptomatic CM-1 between the years 1999 and 2009. Cervical ROM and lordosis were assessed before and after surgery in all patients. Collected data also included clinical improvement, as well as surgical complications after the procedure. Patients were divided into 2 groups. The first group underwent a posterior fossa bony decompression alone, while the second group additionally received an expansile duraplasty. Patients were further subdivided into 3 subgroups on the basis of the severity of tonsillar herniation. A total of 76 patients fit our selection criteria. Fifty-five patients belonged to the duraplasty group. Twenty-one patients underwent bony decompression alone. The 2 groups were statistically demographically and clinically similar. There was no difference in clinical outcome or in ROM and cervical lordosis between the groups except for patients with severe tonsillar herniation (CM-I grade 3). These patients had a statistically significant improvement in their postoperative cervical motility without compromising their spinal stability. Adding an expansile duraplasty to craniovertebral decompression in CM-1 patients with severe tonsillar herniation may restore cervical ROM while preserving stability and alignment. This may relieve postoperative pain and improve clinical prognosis. Copyright © 2016 Elsevier Inc. All rights reserved.

Posterior fossa reconstruction using titanium plate for the treatment of cerebellar ptosis after decompression for Chiari malformation.

PubMed

Udani, Vikram; Holly, Langston T; Chow, Daniel; Batzdorf, Ulrich

2014-01-01

We describe our use of a perforated titanium plate to perform a partial posterior fossa cranioplasty in the treatment of cerebellar ptosis and dural ectasia after posterior fossa decompression (PFD). Twelve patients who had undergone PFD underwent posterior fossa reconstruction using a titanium plate. Symptoms were related to either descent of the cerebellum into the decompression or to dural ectasia into the craniectomy defect. Twelve patients who had undergone large suboccipital craniectomies and who presented with persistent headaches and some with neurological symptoms related to syringomyelia, underwent reoperation with placement of a small titanium plate. Ten of 12 patients showed symptomatic improvement after reoperation. Placement of a titanium plate appears to be an effective method of treatment of cerebellar ptosis and dural ectasia after PFD for Chiari malformation. Copyright © 2014 Elsevier Inc. All rights reserved.

Microvascular Decompression for Trigeminal Neuralgia: Technical Refinement for Complication Avoidance.

PubMed

Tomasello, Francesco; Esposito, Felice; Abbritti, Rosaria V; Angileri, Filippo F; Conti, Alfredo; Cardali, Salvatore M; La Torre, Domenico

2016-10-01

Microvascular decompression (MVD) represents the most effective and safe surgical option for the treatment of trigeminal neuralgia since it was first popularized by Jannetta 50 years ago. Despite several advances, complications such as cerebellar and vascular injury, hearing loss, muscular atrophy, cerebrospinal fluid (CSF) leak, postoperative cutaneous pain, and sensory disturbances still occur and may negatively affect the outcome. We propose some technical nuances of the surgical procedure that were used in our recent series. We used a novel hockey stick-shaped retromastoid skin incision, preserving the major nerves of the occipital and temporal areas. Microsurgical steps were performed without the use of retractors. CSF leakage was prevented with a watertight dural closure and multilayer osteodural reconstruction. The refined surgical steps were perfected in the last consecutive 15 cases of our series. In these cases we did not record any cutaneous pain, sensory disturbances, or CSF leakage. The average diameter of the craniectomy was 18 mm. No patient reported major complications related to the intradural microsurgical maneuvers. In all cases the neurovascular conflict was found and solved with a good outcome in terms of pain disappearance. Our minimally invasive approach was demonstrated to guarantee an optimal exposure of the cerebellopontine angle and minimize the rate of complications related to skin incision and muscular dissection, microsurgical steps, and closure. Copyright © 2016 Elsevier Inc. All rights reserved.

Paradoxical Brain Herniation After Decompressive Craniectomy Provoked by Drainage of Subdural Hygroma.

PubMed

Nasi, Davide; Dobran, Mauro; Iacoangeli, Maurizio; Di Somma, Lucia; Gladi, Maurizio; Scerrati, Massimo

2016-07-01

Paradoxical brain herniation (PBH) is a rare and potentially life-threatening complication of decompressive craniectomy (DC) and results from the combined effects of brain gravity, atmospheric pressure and intracranial hypotension causing herniation in the direction opposite to the site of the DC with subsequent brainstem compression. To date, the cases of PBH reported in literature are spontaneous or provoked by a lumbar puncture, a cerebrospinal fluid (CSF) shunt, or ventriculostomy. We present an uncommon case of PBH provoked by percutaneous drainage of a huge subdural hygroma (SH) ipsilateral to the decompressive craniectomy causing mass effect and neurologic deterioration. After percutaneous evacuation of SH, the patient became unresponsive with dilated and fixed left pupil. A brain computed tomography scan showed marked midline shift in the direction opposite to the craniectomy site with subfalcine herniation and effacement of the peripontine cisterns. Paradoxical brain herniation (PBH) was diagnosed. Conservative treatment failed, and the patient required an emergency cranioplasty for reverse PBH. The present case highlights the possibility that all forms of CSF depletion, including percutaneous drainage of subdural CSF collection and not only CSF shunting and/or lumbar puncture, can be dangerous for patients with large craniotomies and result in PBH. Moreover, an emergency cranioplasty could represent a safe and effective procedure in patients not responding to conservative treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

Hearing outcomes after loss of brainstem auditory evoked potentials during microvascular decompression.

PubMed

Thirumala, Parthasarathy D; Krishnaiah, Balaji; Habeych, Miguel E; Balzer, Jeffrey R; Crammond, Donald J

2015-04-01

The primary aim of this paper is to study the pre-operative characteristics, intra-operative changes and post-operative hearing outcomes in patients after complete loss of wave V of the brainstem auditory evoked potential. We retrospectively analyzed the brainstem auditory evoked potential data of 94 patients who underwent microvascular decompression for hemifacial spasm at our institute. Patients were divided into two groups - those with and those without loss of wave V. The differences between the two groups and outcomes were assessed using t-test and chi-squared tests. In our study 23 (24%) patients out of 94 had a complete loss of wave V, with 11 (48%) patients experiencing transient loss and 12 (52%) patients experiencing permanent loss. The incidence of hearing loss in patients with no loss of wave V was 5.7% and 26% in patients who did experience wave V loss. The incidence of hearing change in patients with no loss of wave V was 12.6% and 30.43% in patients who did experience wave V loss. Loss of wave V during the procedure or at the end of procedure significantly increases the odds of hearing loss. Hearing change is a significant under-reported clinical condition after microvascular decompression in patients who have loss of wave V. Copyright © 2014 Elsevier Ltd. All rights reserved.

Decompression sickness during simulated extravehicular activity: ambulation vs. non-ambulation.

PubMed

Webb, James T; Beckstrand, Devin P; Pilmanis, Andrew A; Balldin, Ulf I

2005-08-01

Extravehicular activity (EVA) is required from the International Space Station on a regular basis. Because of the weightless environment during EVA, physical activity is performed using mostly upper-body movements since the lower body is anchored for stability. The adynamic model (restricted lower-body activity; non-ambulation) was designed to simulate this environment during earthbound studies of decompression sickness (DCS) risk. DCS symptoms during ambulatory (walking) and non-ambulatory high altitude exposure activity were compared. The objective was to determine if symptom incidences during ambulatory and non-ambulatory exposures are comparable and provide analogous estimates of risk under otherwise identical conditions. A retrospective analysis was accomplished on DCS symptoms from 2010 ambulatory and 330 non-ambulatory exposures. There was no significant difference between the overall incidence of DCS or joint-pain DCS in the ambulatory (49% and 40%) vs. the non-ambulatory exposures (53% and 36%; p > 0.1). DCS involving joint pain only in the lower body was higher during ambulatory exposures (28%) than non-ambulatory exposures (18%; p < 0.01). Non-ambulatory exposures terminated more frequently with non-joint-pain DCS (17%) or upper-body-only joint pain (18%) as compared with ambulatory exposures, 9% and 11% (p < 0.01), respectively. These findings show that lower-body, weight-bearing activity shifts the incidence of joint-pain DCS from the upper body to the lower body without altering the total incidence of DCS or joint-pain DCS. Use of data from previous and future subject exposures involving ambulatory activity while decompressed appears to be a valid analogue of non-ambulatory activity in determining DCS risk during simulated EVA studies.

Push versus pull gastrostomy in cancer patients: A single center retrospective analysis of complications and technical success rates.

PubMed

Currie, B M; Getrajdman, G I; Covey, A M; Alago, W; Erinjeri, J P; Maybody, M; Boas, F E

2018-04-28

To compare the technical success and complication rates of push versus pull gastrostomy tubes in cancer patients, and to examine their dependence on operator experience. A retrospective review was performed of 304 cancer patients (170 men, 134 women; mean age 60.3±12.6 [SD], range: 19-102 years) referred for primary gastrostomy tube placement, 88 (29%) of whom had a previously unsuccessful attempt at percutaneous endoscopic gastrostomy (PEG) placement. Analyzed variables included method of insertion (push versus pull), indication for gastrostomy, technical success, operator experience, and procedure-related complications within 30 days of placement. Gastrostomy tubes were placed for feeding in 189 patients and palliative decompression in 115 patients. Technical success was 91%: 78% after endoscopy had previously been unsuccessful and 97% when excluding failures associated with prior endoscopy. In the first 30 days, there were 29 minor complications (17.2%) associated with push gastrostomies, and only 8 minor complications (7.5%) with pull gastrostomies (P<0.05). There was no significant difference in major complications (push gastrostomy 5.3%, pull gastrostomy 5.6%). For decompressive gastrostomy tubes, the pull technique resulted in lower rates of both minor and major complications. There was no difference in complications or technical success rates for more versus less experienced operators. Pull gastrostomy tube placement had a lower rate of complications than push gastrostomy tube placement, especially when the indication was decompression. The technical success rate was high, even after a failed attempt at endoscopic placement. Both the rates of success and complications were independent of operator experience. Copyright © 2018 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Flap reconstruction does not increase complication rates following surgical resection of extremity soft tissue sarcoma.

PubMed

Slump, Jelena; Hofer, Stefan O P; Ferguson, Peter C; Wunder, Jay S; Griffin, Anthony M; Hoekstra, Harald J; Bastiaannet, Esther; O'Neill, Anne C

2018-02-01

Flap reconstruction plays an essential role in the surgical management of extremity soft tissue sarcoma (ESTS) for many patients. But flaps increase the duration and complexity of the surgery and their contribution to overall morbidity is unclear. This study directly compares the complication rates in patients with ESTS undergoing either flap reconstruction or primary wound closure and explores contributing factors. Eight hundred and ninety-seven patients who underwent ESTS resection followed by primary closure (631) or flap reconstruction (266) were included in this study. Data on patient, tumour and treatment variables and post-operative medical and surgical complications were collected. Univariate and multivariate regression analyses were performed to identify independent predictors of complications. Post-operative complications occurred in 33% of patients. Flap patients were significantly older, had more advanced disease and were more likely to require neoadjuvant chemo- and radiotherapy. There was no significant difference in complication rates following flap reconstruction compared to primary closure on multivariate analysis (38 vs 30.9% OR 1.12, CI 0.77-1.64, p = 0.53). Pre-operative radiation and distal lower extremity tumour location were significant risk factors in patients who underwent primary wound closure but not in those who had flap reconstruction. Patients with comorbidities, increased BMI and systemic disease were at increased risk of complications following flap reconstruction. Flap reconstruction is not associated with increased post-operative complications following ESTS resection. Flaps may mitigate the effects of some risk factors in selected patients. Copyright © 2017. Published by Elsevier Ltd.

Phrenic nerve decompression for the management of unilateral diaphragmatic paralysis - preoperative evaluation and operative technique.

PubMed

Hoshide, Reid; Brown, Justin

2017-01-01

Unilateral diaphragmatic paralysis (UDP) can be a very disabling, typically causing shortness of breath and reduced exercise tolerance. We present a case of a surgical decompression of the phrenic nerve of a patient who presented with UDP, which occurred following cervical spine surgery. The workup for the etiology of UDP demonstrated paradoxical movement on "sniff test" and notably impaired pulmonary function tests. Seven months following the onset of the UDP, he underwent a surgical decompression of the phrenic nerve at the level of the anterior scalene. He noted rapid symptomatic improvement following surgery and reversal of the above noted objective findings was documented. At his 4-year follow-up, he had complete resolution of his clinical symptoms. Repeated physiologic testing of his respiratory function had shown a complete reversal of his UDP. Anatomical compression of the phrenic nerve by redundant neck vasculature should be considered in the differential diagnosis of UDP. Here we demonstrated the techniques in workup and surgical management, with both subjective and objective evidence of success.

Effect of orbital bony decompression for Graves' orbitopathy on the volume of extraocular muscles.

PubMed

Alsuhaibani, Adel H; Carter, Keith D; Policeni, Bruno; Nerad, Jeffrey A

2011-09-01

To evaluate the change in the rectus muscle volume following orbital bony wall decompression for Graves' orbitopathy. We used a computer program (syngo Volume Evaluation) to measure the rectus muscles from the digital preoperative and postoperative orbital CT. Of the 25 patients (20 women and five men; mean age 46 (range 18-64) years) enrolled in the study. A significant increase (mean 0.23 ml (16.5%) of preoperative volume; p=0.005) in the volume of the medial rectus muscle (MRM) was detected postoperatively, whereas no significant changes were found in the volume of the other rectus muscles and between eyes that underwent surgery in the active and inactive phases of the disease. A significant negative association was observed between the time of postoperative CT scans and the change in the MRM volume (p=0.0004) (a mean increase of 68% of preoperative MRM volume for those measured between 3 and 9 months, and a mean decrease in the volume of 50% for those measured between 41 and 50 months). The change in the volume of the MRM may partly explain the variability in the proptosis reduction following orbital decompression.

Simultaneous cranioplasty and subdural-peritoneal shunting for contralateral symptomatic subdural hygroma following decompressive craniectomy.

PubMed

Lin, Muh-Shi; Chen, Tzu-Hsuan; Kung, Woon-Man; Chen, Shuo-Tsung

2015-01-01

Contralateral subdural hygroma caused by decompressive craniectomy tends to combine with external cerebral herniation, causing neurological deficits. Nine patients who underwent one-stage, simultaneous cranioplasty and contralateral subdural-peritoneal shunting were included in this study. Clinical outcome was assessed by Glasgow Outcome Scale as well as Glasgow Coma Scale, muscle power scoring system, and complications. Postoperative computed tomography scans demonstrated completely resolved subdural hygroma and reversed midline shifts, indicating excellent outcome. Among these 9 patients, 4 patients (44%) had improved GOS following the proposed surgery. Four out of 4 patients with lethargy became alert and orientated following surgical intervention. Muscle strength improved significantly 5 months after surgery in 7 out of 7 patients with weakness. Two out of 9 patients presented with drowsiness due to hydrocephalus at an average time of 65 days after surgery. Double gradient shunting is useful to eliminate the respective hydrocephalus and contralateral subdural hygroma. The described surgical technique is effective in treating symptomatic contralateral subdural hygroma following decompressive craniectomy and is associated with an excellent structural and functional outcome. However, subdural-peritoneal shunting plus cranioplasty thoroughly resolves the subdural hygroma collection, which might deteriorate the cerebrospinal fluid circulation, leading to hydrocephalus.

Vehicle-triggered video compression/decompression for fast and efficient searching in large video databases

NASA Astrophysics Data System (ADS)

Bulan, Orhan; Bernal, Edgar A.; Loce, Robert P.; Wu, Wencheng

2013-03-01

Video cameras are widely deployed along city streets, interstate highways, traffic lights, stop signs and toll booths by entities that perform traffic monitoring and law enforcement. The videos captured by these cameras are typically compressed and stored in large databases. Performing a rapid search for a specific vehicle within a large database of compressed videos is often required and can be a time-critical life or death situation. In this paper, we propose video compression and decompression algorithms that enable fast and efficient vehicle or, more generally, event searches in large video databases. The proposed algorithm selects reference frames (i.e., I-frames) based on a vehicle having been detected at a specified position within the scene being monitored while compressing a video sequence. A search for a specific vehicle in the compressed video stream is performed across the reference frames only, which does not require decompression of the full video sequence as in traditional search algorithms. Our experimental results on videos captured in a local road show that the proposed algorithm significantly reduces the search space (thus reducing time and computational resources) in vehicle search tasks within compressed video streams, particularly those captured in light traffic volume conditions.

Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis

PubMed Central

Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred H

2017-01-01

Background Lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD) using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis. Methods This study evaluated the 5-year clinical outcomes for IPD (Superion®) from a randomized controlled US Food and Drug Administration (FDA) noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf), and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). Results At 5 years, 84% of patients (74 of 88) demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88), 81% (71 of 88), and 90% (79 of 88) for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85) and 65% (55 of 85), respectively, and the success rate for ODI was 65% (57 of 88). Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P<0.001). Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P<0.0001). Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years. Conclusion After 5 years of follow-up, IPD with a stand-alone spacer provides sustained clinical benefit. PMID:28919727

Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis.

PubMed

Nunley, Pierce D; Patel, Vikas V; Orndorff, Douglas G; Lavelle, William F; Block, Jon E; Geisler, Fred H

2017-01-01

Lumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD) using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis. This study evaluated the 5-year clinical outcomes for IPD (Superion ® ) from a randomized controlled US Food and Drug Administration (FDA) noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf), and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). At 5 years, 84% of patients (74 of 88) demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88), 81% (71 of 88), and 90% (79 of 88) for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85) and 65% (55 of 85), respectively, and the success rate for ODI was 65% (57 of 88). Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P <0.001). Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P <0.0001). Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years. After 5 years of follow-up, IPD with a stand-alone spacer provides sustained clinical benefit.

Response Styles in Rating Scales: Simultaneous Modeling of Content-Related Effects and the Tendency to Middle or Extreme Categories

ERIC Educational Resources Information Center

Tutz, Gerhard; Berger, Moritz

2016-01-01

Heterogeneity in response styles can affect the conclusions drawn from rating scale data. In particular, biased estimates can be expected if one ignores a tendency to middle categories or to extreme categories. An adjacent categories model is proposed that simultaneously models the content-related effects and the heterogeneity in response styles.…

Nasogastric tube versus gastrostomy tube for gastric decompression in abdominal surgery: a prospective, randomized trial comparing patients' tube-related inconvenience.

PubMed

Hoffmann, S; Koller, M; Plaul, U; Stinner, B; Gerdes, B; Lorenz, W; Rothmund, M

2001-11-01

Perioperative decompression of the stomach is still a common procedure and can be achieved using either nasogastric tubes (NTs) or gastrostomy tubes (GTs). While both procedures appear to be equally effective, some authors believe that NTs are less convenient for patients than GTs. However, to date, no reliable prospective data are available on this issue. We conducted a prospective, randomized trial comparing NTs versus GTs with a total of 110 patients undergoing elective colon surgery. The primary outcome measure was the patient's tube-related inconvenience and pain, assessed in a standardized interview on day 2 after surgery and quantified by means of a visual-analog scale (VAS). A questionnaire including the EORTC QLQ-C30 and additional items regarding retrospective tube-related judgements was administered on the day of discharge and 4 weeks after discharge. Secondary endpoints were the therapy-related morbidity and general complications. When patients were asked which of their drainage tubes (all patients had three or four drainage tubes, such as decompression drains, urinary drains, central venous line) was most inconvenient, 43% (CI 33-53%) in the NT group reported that the NT was most inconvenient, while only 4% (CI 1-10%) of the GT patients judged the GT most inconvenient ( P<0.001, Chi(2) test). This effect was also found in VAS ratings of inconvenience and discomfort ( P<0.01). Also postoperatively (p.o.), NT patients evidenced less preference for their tube system (day 2 p.o.: 71%, CI 61-80%; 4 weeks p.o.: 66%, CI 56-75%) than did GT patients (day 2 p.o.: 94%, CI 88-98%; 4 weeks p.o.: 91% CI 84-96%); again, these differences were statistically significant ( P<0.02; Chi(2) test). No differences between groups emerged regarding global quality of life or conventional clinical outcomes. This prospective randomized trial supports the clinical observation that NT causes more subjective inconvenience than GT. In cases when a prolonged postoperative ileus is

Increasing Lower Extremity Injury Rates Across the 2009-2010 to 2014-2015 Seasons of National Collegiate Athletic Association Football: An Unintended Consequence of the "Targeting" Rule Used to Prevent Concussions?

PubMed

Westermann, Robert W; Kerr, Zachary Y; Wehr, Peter; Amendola, Annuziato

2016-12-01

Sports-related concussions (SRCs) have gained increased societal interest in the past decade. The National Collegiate Athletic Association (NCAA) has implemented legislation and rule changes to decrease the incidence and risk of head injury impacts. The "targeting" rule forbids initiating contact with the crown of a helmet and targeting defenseless players in the head and neck area; however, there are concerns that this rule change has unintentionally led to an increased incidence of lower extremity injuries. The purpose of this study was to evaluate the change in lower extremity injury rates in NCAA football during the 2009-2010 to 2014-2015 seasons. We hypothesized that the lower extremity injury rate has increased across the time period. Descriptive epidemiology study. Sixty-eight NCAA football programs provided 153 team-seasons of data to the NCAA Injury Surveillance Program. Lower extremity injuries (ie, hip/groin, upper leg/thigh, knee, lower leg/Achilles, foot/toes) and SRCs sustained during NCAA football games were examined. We calculated injury rates per 1000 athlete-exposures (AEs) for lower extremity injuries and SRCs. Rate ratios (RRs) compared injury rates between the 2009-2010 to 2011-2012 and 2012-2013 to 2014-2015 seasons. Overall, 2400 lower extremity injuries were reported during the 2009-2010 to 2014-2015 seasons; most were to the knee (33.6%) and ankle (28.5%) and caused by player contact (59.2%). The lower extremity injury rate increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (23.55 vs 20.45/1000 AEs, respectively; RR, 1.15; 95% CI, 1.06-1.25). This finding was retained when restricted to injuries due to player contact (RR, 1.19; 95% CI, 1.07-1.32) but not for injuries due to noncontact/overuse (RR, 0.96; 95% CI, 0.80-1.14). When examining player contact injury rates by anatomic site, only ankle injuries had an increase (RR, 1.36; 95% CI, 1.13-1.64). The SRC rate also increased in 2012-2013 to 2014-2015 compared with

Use of liposomal bupivacaine in the postoperative management of posterior spinal decompression.

PubMed

Grieff, Anthony N; Ghobrial, George M; Jallo, Jack

2016-07-01

OBJECTIVE The aim in this paper was to evaluate the efficacy of long-acting liposomal bupivacaine in comparison with bupivacaine hydrochloride for lowering postoperative analgesic usage in the management of posterior cervical and lumbar decompression and fusion. METHODS A retrospective cohort-matched chart review of 531 consecutive cases over 17 months (October 2013 to February 2015) for posterior cervical and lumbar spinal surgery procedures performed by a single surgeon (J.J.) was performed. Inclusion criteria for the analysis were limited to those patients who received posterior approach decompression and fusion for cervical or lumbar spondylolisthesis and/or stenosis. Patients from October 1, 2013, through December 31, 2013, received periincisional injections of bupivacaine hydrochloride, whereas after January 1, 2014, liposomal bupivacaine was solely administered to all patients undergoing posterior approach cervical and lumbar spinal surgery through the duration of treatment. Patients were separated into 2 groups for further analysis: posterior cervical and posterior lumbar spinal surgery. RESULTS One hundred sixteen patients were identified: 52 in the cervical cohort and 64 in the lumbar cohort. For both cervical and lumbar cases, patients who received bupivacaine hydrochloride required approximately twice the adjusted morphine milligram equivalent (MME) per day in comparison with the liposomal bupivacaine groups (5.7 vs 2.7 MME, p = 0.27 [cervical] and 17.3 vs 7.1 MME, p = 0.30 [lumbar]). The amounts of intravenous rescue analgesic requirements were greater for bupivacaine hydrochloride in comparison with liposomal bupivacaine in both the cervical (1.0 vs 0.39 MME, p = 0.31) and lumbar (1.0 vs 0.37 MME, p = 0.08) cohorts as well. None of these differences was found to be statistically significant. There were also no significant differences in lengths of stay, complication rates, or infection rates. A subgroup analysis of both cohorts of opiate-naive versus

Temporary percutaneous T-fastener gastropexy and continuous decompressive gastrostomy in dogs with experimentally induced gastric dilatation.

PubMed

Fox-Alvarez, W Alexander; Case, J Brad; Cooke, Kirsten L; Garcia-Pereira, Fernando L; Buckley, Gareth J; Monnet, Eric; Toskich, Beau B

2016-07-01

OBJECTIVE To evaluate a percutaneous, continuous gastric decompression technique for dogs involving a temporary T-fastener gastropexy and self-retaining decompression catheter. ANIMALS 6 healthy male large-breed dogs. PROCEDURES Dogs were anesthetized and positioned in dorsal recumbency with slight left-lateral obliquity. The gastric lumen was insufflated endoscopically until tympany was evident. Three T-fasteners were placed percutaneously into the gastric lumen via the right lateral aspect of the abdomen, caudal to the 13th rib and lateral to the rectus abdominis muscle. Through the center of the T-fasteners, a 5F locking pigtail catheter was inserted into the gastric lumen and attached to a device measuring gas outflow and intragastric pressure. The stomach was insufflated to 23 mm Hg, air was allowed to passively drain from the catheter until intraluminal pressure reached 5 mm Hg for 3 cycles, and the catheter was removed. Dogs were hospitalized and monitored for 72 hours. RESULTS Mean ± SD catheter placement time was 3.3 ± 0.5 minutes. Mean intervals from catheter placement to a ≥ 50% decrease in intragastric pressure and to ≤ 6 mm Hg were 2.1 ± 1.3 minutes and 8.4 ± 5.1 minutes, respectively. After catheter removal, no gas or fluid leakage at the catheter site was visible laparoscopically or endoscopically. All dogs were clinically normal 72 hours after surgery. CONCLUSIONS AND CLINICAL RELEVANCE The described technique was performed rapidly and provided continuous gastric decompression with no evidence of postoperative leakage in healthy dogs. Investigation is warranted to evaluate its effectiveness in dogs with gastric dilatation-volvulus.

Utility of Brainstem Trigeminal Evoked Potentials in Patients With Primary Trigeminal Neuralgia Treated by Microvascular Decompression.

PubMed

Zhu, Jin; Zhang, Xin; Zhao, Hua; Tang, Yin-Da; Ying, Ting-Ting; Li, Shi-Ting

2017-09-01

To investigate the characteristics of brainstem trigeminal evoked potentials (BTEP) waveform in patients with and without trigeminal neuralgia (TN), and to discuss the utility of BTEP in patients with primary TN treated by microvascular decompression (MVD). A retrospective review of 43 patients who underwent BTEP between January 2016 and June 2016, including 33 patients with TN who underwent MVD and 10 patients without TN. Brainstem trigeminal evoked potentials characteristics of TN and non-TN were summarized, in particular to compare the BTEP changes between pre- and post-MVD, and to discover the relationship between BTEP changes and surgical outcome. Brainstem trigeminal evoked potentials can be recorded in patients without trigeminal neuralgia. Abnormal BTEP could be recorded when different branches were stimulated. After decompression, the original W2, W3 disappeared and then replaced by a large wave in most patients, or original wave poorly differentiated improved in some patients, showed as shorter latency and (or) amplitude increased. Brainstem trigeminal evoked potentials waveform of healthy side in patients with trigeminal neuralgia was similar to the waveform of patients without TN. In 3 patients, after decompression the W2, W3 peaks increased, and the latency, duration, IPLD did not change significantly. Until discharge, 87.9% (29/33) of the patients presented complete absence of pain without medication (BNI I) and 93.9% (31/33) had good pain control without medication (BNI I-II). Brainstem trigeminal evoked potentials can reflect the conduction function of the trigeminal nerve to evaluate the functional level of the trigeminal nerve conduction pathway. The improvement and restoration of BTEP waveforms are closely related to the postoperative curative effect.

Vertebral artery pexy for microvascular decompression of the facial nerve in the treatment of hemifacial spasm.

PubMed

Ferreira, Manuel; Walcott, Brian P; Nahed, Brian V; Sekhar, Laligam N

2011-06-01

Hemifacial spasm (HFS) is caused by arterial or venous compression of cranial nerve VII at its root exit zone. Traditionally, microvascular decompression of the facial nerve has been an effective treatment for posterior inferior and anterior inferior cerebellar artery as well as venous compression. The traditional technique involves Teflon felt or another construct to cushion the offending vessel from the facial nerve, or cautery and division of the offending vein. However, using this technique for severe vertebral artery (VA) compression can be ineffective and fraught with complications. The authors report the use of a new technique of VA pexy to the petrous or clival dura mater in patients with HFS attributed to a severely ectatic and tortuous VA, and detail the results in a series of patients. Six patients with HFS due to VA compression underwent a retrosigmoid craniotomy, combined with a far-lateral approach in some patients. On identification of the site of VA compression, the vessel was mobilized adequately for the decompression. Great care was taken to avoid kinking the perforating vessels arising from the VA. Two 8-0 nylon sutures were passed through to the wall of the VA and then through the clival or petrous dura, and then tied to alleviate compression on cranial nerve VII. Patients were followed for at least 1 year postoperatively (mean 2.7 years, range 1-4 years). All 6 patients had complete resolution of their HFS. Facial function was tested postoperatively, and was stable when compared with the preoperative baseline. Two of the 3 patients with preoperative tinnitus had resolution of this symptom after the procedure. Postoperative imaging demonstrated VA decompression of the facial nerve and no evidence of stroke in all patients. One patient suffered from hearing loss, another developed a postoperative transient unilateral vocal cord paralysis, and a third patient developed a pseudomeningocele that resolved with the placement of a lumbar drain

Classification of orbital morphology for decompression surgery in Graves' orbitopathy: two-dimensional versus three-dimensional orbital parameters.

PubMed

Borumandi, Farzad; Hammer, Beat; Noser, Hansrudi; Kamer, Lukas

2013-05-01

Three-dimensional (3D) CT reconstruction of the bony orbit for accurate measurement and classification of the complex orbital morphology may not be suitable for daily practice. We present an easily measurable two-dimensional (2D) reference dataset of the bony orbit for study of individual orbital morphology prior to decompression surgery in Graves' orbitopathy. CT images of 70 European adults (140 orbits) with unaffected orbits were included. On axial views, the following orbital dimensions were assessed: orbital length (OL), globe length (GL), GL/OL ratio and cone angle. Postprocessed CT data were required to measure the corresponding 3D orbital parameters. The 2D and 3D orbital parameters were correlated. The 2D orbital parameters were significantly correlated to the corresponding 3D parameters (significant at the 0.01 level). The average GL was 25 mm (SD±1.0), the average OL was 42 mm (SD±2.0) and the average GL/OL ratio was 0.6 (SD±0.03). The posterior cone angle was, on average, 50.2° (SD±4.1). Three orbital sizes were classified: short (OL≤40 mm), medium (OL>40 to <45 mm) and large (OL≥45 mm). We present easily measurable reference data for the orbit that can be used for preoperative study and classification of individual orbital morphology. A short and shallow orbit may require a different decompression technique than a large and deep orbit. Prospective clinical trials are needed to demonstrate how individual orbital morphology affects the outcome of decompression surgery.

Experiments on the genesis of bubbles as a result of rapid decompression

PubMed Central

Lever, M. J.; Miller, K. W.; Paton, W. D. M.; Smith, E. B.

1966-01-01

1. The time course of intravascular bubble formation in mice after rapid decompression from 150 Lb/sq. in. has been followed in vivo in a flap preparation of thoracic and abdominal skin. 2. Gas appeared first in the arteries, moving distally after a latent period of 3 min or more. Then bubbles appeared, moving centrally, in the venous system. 3. The arterial bubbles could not be attributed to air forced into the circulation from the lungs or lumen of the gut. ImagesFig. 1 PMID:5912215

Inner Ear Decompression Sickness in the Squirrel Monkey: Observations, Interpretations, and Mechanisms.

DTIC Science & Technology

1983-01-01

hearing were evident in most cases. Symptoms associated with the decompression syndrome , such as joint pain or itching of the skin, were usually...1983:10:225-240). 9 Koordn IPSom pecliaitie ofMeniere’s syndrome in deep sea divers fin Russian). Voenntioed Z. 66’t5 i 67, Pi %lV.§~or CAL %lav IF...Med Suhaquat tlpcrbar 1980;74.89-94. L14. Le Niouci C. Suc B. Asperge A. Traitemnent hyperbare des accidents de l’oreillc interne fits a Is plongee

Spontaneous C1 anterior arch fracture as a postoperative complication of foramen magnum decompression for Chiari malformation type 1