Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Decompression”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed1982

The results of decompression of cord or cauda equina compression from metastatic extradural tumors.

The role of decompression in spinal metastases with neurologic deficit is controversial. This series demonstrates that the benefit from decompression depends on the nature of the tumor and the neurologic status of the patient. Prognosis is good for patients with incomplete paraplegia, intact sphincter control, a long duration of neurologic deficit and pain, and a gradual onset of compression. The prognosis is poor in cases with complete paraplegia, loss of sphincter control, a short duration of neurologic deficit and pain, and a sudden onset of compression. Surgery is not advocated for all cases, because many patients are already very ill. Surgery is recommended only for selective cases in which the prognosis is good. However, decompression is only palliative. Posterior decompression is preferred, inasmuch as the surgery is less extensive compared to anterior decompression and fusion.

Adult↗
PubMed1995

Preliminary experience with percutaneous laser disc decompression in the treatment of sciatica.

OBJECTIVE: To examine the usefulness of percutaneous laser decompression of a herniated lumbar intervertebral disc. DESIGN: A case series. SETTING: A university-affiliated hospital. PATIENTS: Sixteen patients with clinical and radiologic evidence of herniated lumbar intervertebral discs. INTERVENTIONS: Percutaneous introduction of a fine optical fibre into a herniated lumbar disc and delivery of short pulses of laser energy. MAIN OUTCOME MEASURE: The relief of intractable leg pain. RESULTS: Nine of 14 patients with intractable leg pain experienced total relief after percutaneous laser disc decompression. Four patients required subsequent microsurgical discectomy, and one required a decompressive laminectomy. Of the two patients who had back pain as their major complaint, one required microsurgical discectomy after laser disc decompression. CONCLUSIONS: Percutaneous laser disc decompression can relieve sciatica caused by a herniated intervertebral disc. The technique requires limited use of health resources. Preliminary results suggest that an early return to work can be expected in patients successfully relieved of their leg pain.

Adult↗
PubMed1995

Which is the best surgery for Budd-Chiari syndrome: venous decompression or liver transplantation? A single-center experience with 50 patients.

The optimal treatment of Budd-Chiari syndrome (BCS) remains an open question. It is still a matter of controversial discussion whether venous decompression or liver transplantation is superior. To elucidate the role and prognosis of both surgical options in our own experience, a consecutive series of 50 patients treated between 1981 and 1993 was retrospectively analyzed. Twelve patients had different types of portosystemic shunts or local decompressive procedures, and transplantation was performed in 43 cases, including five with previous conventional surgery. The overall mortality of 18 of 50 was conventional surgery. The overall mortality of 18 of 50 was concentrated within the early postoperative period, with no patient lost after 1 year. In the venous decompression group, the success rate was only 29%, and treatment failure was closely related to the finding of cirrhosis or technical problems like vascular thrombosis. After transplantation, early complications were rejection, primary nonfunction, or graft necrosis, and contributed significantly to the risk of sepsis. Thirty of 43 liver recipients are currently alive, including four rescued after failed decompressive surgery, with 1- and 10-year survival of 69%, and excellent recurrence-free rehabilitation. These results clearly indicate that patient selection plays a dominant prognostic role in the treatment of BCS. Venous decompression and liver transplantation should both be integrated in a common therapeutic concept, and the individual decision for the preferred approach must be based on the leading clinical symptom: portal hypertension or liver failure, together with the assessment of reversibility of hepatic damage, and the potential of cure of the underlying disease.

Adolescent↗
PubMed1994

Extensive anterior decompression for mixed cervical spondylosis. Resection of uncovertebral joints, neural and transverse foraminotomy, subtotal corpectomy, and fusion with strut graft.

STUDY DESIGN: This study examined a new operative procedure for treating mixed cervical spondylosis. OBJECTIVES: To relate postoperative results with extensive decompression using a surgical microscope. SUMMARY OF BACKGROUND DATA: Based on the dissection cadavers and clinical practice, extensive anterior decompression has been designed for mixed cervical spondylosis. It has not been reported that the cervical cord, nerve roots, and vertebral arteries have been decompressed thoroughly at the same time. METHODS: Fifteen patients with mixed cervical spondylosis were treated with extensive anterior decompression using an operative microscope. The pathologic segments in all patients were identified preoperatively with cervical radiography, myelography, computed tomography, computed tomographic myelography, and magnetic resonance imaging. The Japanese Orthopaedic Association classification was used to assess the follow-up results. The operative results demonstrated the efficacy of the surgical approach. RESULTS: All patients improved neurologically, with the average Japanese Orthopaedic Association score improving from 6.3 points preoperatively to 12.4 points at follow-up examination. The plain radiography, computed tomography, and magnetic resonance imaging follow-up examination showed that the anterior part of the cervical canal and the transversaria or neural foramina were enlarged, and that there was satisfactory bony fusion without signs of nonunion and other complications. CONCLUSIONS: Extensive anterior decompression (resection of uncovertebral joints, neural and transverse foraminotomy, subtotal corpectomy, and fusion with strut graft), a new surgical procedure for treating mixed cervical spondylosis, led to excellent follow-up results.

Adult↗
PubMed1996

Vulnerability of vertebral artery in anterolateral decompression for cervical spondylosis.

This study aimed to provide anatomic data for the location of the vertebral artery and offer an optimal approach for lateral cervical decompression that minimizes the risk of injury to the vertebral artery. Anatomically, there has been little study documenting the safe zone to prevent vertebral artery injury during the resection of the uncinate process or uncovertebral joint during the lateral decompression of the nerve root. The transverse foramen and its related parameters were measured on dry cervical spines from C3 to C7. The cadaveric cervical spines were dissected to determine a method for resection of the uncovertebral joint with decreased risk of vertebral artery laceration. The anteroposterior diameters of the transverse foramina gradually decreased from C6 to C3. The transverse diameters of the transverse foramina were smaller at C5. The interforaminal distance, width of the vertebrae, interuncinate distance, and the distance from the lateral tip of the uncinate process to the medial border of the transverse foramen became smaller in more cephalad vertebrae. After subtotal vertebrectomy and opening of the anterior walls of the transverse foramina, the resection of the uncovertebral joint and lateral decompression became easier and safer. Anatomic measurements obtained in this study indicate the vertebral artery to be at risk during decompression of the more cephalad vertebrae. The lateral decompression can be completed under direct vision with smaller rongeurs and curettes, rather than with high speed burr after deroofing the anterior walls of transverse foramina and retracting the vertebral artery laterally.

Adult↗
PubMed1996

[Microsurgical endonasal decompression in traumatic and neoplastic optic nerve compression].

UNLABELLED: The therapy of traumatic optic neuropathy remains controversial. Some authors recommend observation and others, the use of megadose corticosteroids or surgical decompression of the optic nerve. Improvements in visual acuity from no light perception (NLP) preoperatively to close to normal visual acuities have been reported after transethmoidal decompression and systemic steroids. The transnasal microscopic approach offers safe and effective access to the optic canal. MATERIALS AND METHODS: Retrospectively 15 patients (13 men/2 women) ranging in age from 17 to 67 years, who were surgically decompressed in the Ear-Nose-Throat Department between 1989 and 1994, were analyzed. Thirteen patients had experienced sudden visual loss after trauma; in 2 patients a tumor was diagnosed. After an initial ophthalmologic examination and CT scans, the patients underwent transnasal decompression of the optic canal for at least 180 degrees. In the postoperative period, visual acuity, pupillary reaction, visual field and optic nerve morphology were monitored. RESULTS: The overall visual results were poor. In 8 patients with no light perception (NLP) preoperatively, no improvement in visual acuity was found. Minor improvements were seen with an initial vision of 20/200 or less. Dramatic improvements were found in both patients with rapidly progressive neoplastic optic nerve compression. No intra- or postoperative complications were seen. CONCLUSION: In our study we were unable to reproduce the good visual results of some series. If there is NLP preoperatively, surgical intervention does not seem to be promising. However, in patients with incurable tumors transnasal decompression of the optic canal offers a minimally invasive palliative measure to preserve and restore vision.

Adolescent↗
PubMed1996

[Detection of microbubbles formed in the blood/CO2 interphase during decompression in barometric conditions similar to laparoscopy].

HYPOTHESIS AND OBJECTIVES: Intraperitoneal insufflation (IPI) with CO2 during laparoscopic surgery establishes a pressure gradient that determines the passage of gas from the peritoneal cavity to the blood and surrounding tissues. The transport and clearance of CO2 are assured by proper sweeping when regional blood flow is adequate in volume and distribution. But if IPI hyperpressure surpasses regional venous capillary pressure (10 to 15 mmHg) and there is no cardio-circulatory adaptation to the phenomenon, CO2 clearance may be compromised. Under these conditions, the expected post-insufflation increase in PetCO2 will not take place. Bearing in mind the physical characteristics of CO2, retention of this gas in the intraperitoneal cavity produces blood and tissue saturation under a higher-than-atmospheric pressure, after a certain period of time in contact. Rapid intraperitoneal decompression after laparoscopic surgery carries with it the risk of microbubble formation due to release of CO2 that had been dissolved under hyperbaric conditions. MATERIAL AND METHODS: To test this hypothesis, the barometric conditions of laparoscopy were reproduced inside an observation capsule containing blood and CO2. RESULTS: Magnification revealed that after decompression bubbles formed in the blood/CO2 interphase. The images were recorded on magnetic videotape. Thirty minutes after decompression, the bubbles could still be seen, even after the interphase was swept with a current of air. DISCUSSION: Rapid intraperitoneal decompression after laparoscopy can generate the formation of microbubbles which, if not eliminated, will give rise to local ischemic manifestations. This same decompression, correcting the local circulatory alterations and activating the CO2 transport that had been compromised, could introduce gas bubbles into the blood stream such as are responsible for delayed gaseous microembolism. The simultaneous observation of changes in PetCO2 (stability or post-insufflation decreases) and hemodynamic parameters during laparoscopy, would allow evolving anomalies to be detected early and therapeutic action to be taken to prevent the formation of microbubbles.

Carbon Dioxide↗
PubMedDate not supplied

[Method of computing positive pressure in the human lung following space cabin decompression].

The paper presents a mathematical model and differential equations to be used in computer-aided estimations of the positive pressure in human lugs upon space cabin blast decompression. The paper gives a simplified method of computing the pressure which utilizes a special diagram of decompression of a rigid container communicating with the cabin through a hole of a constant area. The characteristic feature of the method is a simultaneous computation of the air outflowing from the lungs and their expansion during decompression. The paper illustrates the advantage of the simultaneous computation of the processes and specifies the pulmonary regions of positive pressure at given blast decompressions. The paper compares theoretical and experimental (data by foreign researchers) peak values of the positive pressure in human lungs during blast decompression, indicating good agreement of the results.

Atmospheric Pressure↗
PubMed1987

Computational decompression models.

Early computational models for decompression are based on supersaturation assumptions for dissolved gases. Such models, and our understanding of decompression biophysics, have been extended in the past 20 years by analyses of phase separation of gases. Generally termed thermodynamic decompression (or phase equilibration), these studies postulate a continuous exchange of inert gas between tissues and nucleation sites (gas micropockets), consistent with many commonplace phenomena. Postulates lead to decompression schedules and transfer mechanisms that differ from their earlier predecessors. The precise physical and computational bases supporting both viewpoints are described and contrasted.

Decompression↗
PubMed2003

Diving up to 60 m depth followed by decompression has no effect on pro-enzyme and total thrombin activatable fibrinolysis inhibitor antigen concentration.

The aim of our study was to investigate the effect of two different hyperbaric exposures followed by decompression on thrombin activatable fibrinolysis inhibitor (TAFI) concentration and activity. The hyperbaric conditions correspond to diving to 30 and 60 m water depth. Thirty-four male divers were tested in decompression habitat LSH-200, with air as a breathing medium. The pro-enzyme and total TAFI antigen concentration were measured. We did not observed significant changes of either pro-enzyme or total TAFI antigen concentration after both series of exposures followed by decompression. The results may suggest that TAFI plays only a marginal role, if any, in the regulation of induced fibrinolysis in divers, which may contribute to bleeding episodes in a course of decompression sickness.

Adult↗
PubMed1984

Morphological and physiological responses of the lungs of dogs to acute decompression.

The lung's response to decompression was studied in dogs anesthetized with pentobarbital sodium. Arterial pressure, hematocrit, right ventricular pressure, left ventricular end-diastolic pressure (LVEDP), dynamic compliance (CL), pulmonary resistance (RL), and arterial PO2, PCO2, and pH were measured prior to and for 3 h after a simulated air dive to 300 feet of seawater. Bronchoscopy was performed predive and at 3 h postdive. At 3 h animals were killed, and sections of lung were excised for histological examination. The decompression profile used regularly produced pulmonary hypertension, systemic hypotension, hemoconcentration, and arterial hypoxemia. CL fell in all but one dived animal. RL was more variable but remained unchanged postdive in most animals. The decompression stress did not alter the bronchoscopic and histological appearance of the airway mucosa. Pulmonary edema was regularly observed in histological sections and occurred without elevations of LVEDP. We concluded that noncardiac pulmonary edema is the principal response of the lung to decompression stress.

Animals↗
PubMed1998

Serum alpha 2-antiplasmin activity following rapid decompression from a hyperbaric environment in rabbit.

Changes in serum alpha 2-antyplasmin (alpha 2-AP) in rabbits exposed to hyperbaric environment (6 ATA, 40 min.) and 5-minute decompression (1 ATA/min) were estimated. 10 male New Zealand white rabbits consisted the studied group, and 10 the control group. Blood samples were collected in rabbits from the femoral artery: once before placing the rabbit in the hyperbaric chamber, and three times after opening the chamber: just after decompression, at 10 and 20 minutes after collecting the second sample. Serum alpha 2-AP activity was measured using chromogenic substrates. Rapid decompression in rabbits exposed to hyperbaric environment at 6 ATA caused decrease in serum alpha 2-AP activity. Significant decrease in serum alpha 2-AP activity was observed at 20 min. after decompression. Serum alpha 2-AP activity can be applied in diagnostics of DCS.

Animals↗
PubMed1976

Decompression sickness during saturation dives.

Available Navy saturation diving data were analyzed for an evaluation of the therapeutic adequacy of decompression sickness treatment procedures and for delineation of precipitant factors in the etiology and treatment of decompression sickness during saturation dives. None of the cases of decompression sickness recorded during saturation dives involved more than musculoskeletal or joint pain, and in 96% of the cases the joint pain was confined to the diver's knees. In 89% of the cases symptoms appeared while the divers were still under pressure. The subsequent recompression treatment of these cases resulted in full relief in only 35% of the cases; the remaining 65% completed the therapy and subsequent decompression with residual pain which diminished over a period of weeks. The adequacy of the recompression appears to be inversely proportional to the depth of reported onset of symptoms and the time required to obtain even partial relief is directly related to the magnitude of the recompression ratio used. Four explanations are suggested for the limited recompression therapy common in saturation diving: increase in musculoskeletal pain with recompression, peer pressure to avoid extension of the chamber confinement, lack of severe neurological symptoms, and the tremendous depths required to obtain a reasonable recompression ratio. The author further suggests that future treatment procedures will require a departure from the accepted concept of radically decreasing the volume of inert gas bubbles by increasing pressure.

Analysis of Variance↗
PubMed1997

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

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.

Aerospace Medicine↗
PubMed2004

A deep stop during decompression from 82 fsw (25 m) significantly reduces bubbles and fast tissue gas tensions.

In spite of many modifications to decompression algorithms, the incidence of decompression sickness (DCS) in scuba divers has changed very little. The success of stage, compared to linear ascents, is well described yet theoretical changes in decompression ratios have diminished the importance of fast tissue gas tensions as critical for bubble generation. The most serious signs and symptoms of DCS involve the spinal cord, with a tissue half time of only 12.5 minutes. It is proposed that present decompression schedules do not permit sufficient gas elimination from such fast tissues, resulting in bubble formation. Further, it is hypothesized that introduction of a deep stop will significantly reduce fast tissue bubble formation and neurological DCS risk. A total of 181 dives were made to 82 fsw (25 m) by 22 volunteers. Two dives of 25 min and 20 min were made, with a 3 hr 30 min surface interval and according to 8 different ascent protocols. Ascent rates of 10, 33 or 60 fsw/min (3, 10, 18 m/min) were combined with no stops or a shallow stop at 20 fsw (6 m) or a deep stop at 50 fsw (15 m) and a shallow at 20 fsw (6 m). The highest bubbles scores (8.78/9.97), using the Spencer Scale (SS) and Extended Spencer Scale (ESS) respectively, were with the slowest ascent rate. This also showed the highest 5 min and 10 min tissue loads of 48% and 75%. The lowest bubble scores (1.79/2.50) were with an ascent rate of 33 fsw (10 m/min) and stops for 5 min at 50 fsw (15 m) and 20 fsw (6 m). This also showed the lowest 5 and 10 min tissue loads at 25% and 52% respectively. Thus, introduction of a deep stop significantly reduced Doppler detected bubbles together with tissue gas tensions in the 5 and 10 min tissues, which has implications for reducing the incidence of neurological DCS in divers.

Atmospheric Pressure↗
PubMed1975

Bubble growth and mechanical properties of tissue in decompression.

A survey of decompression literature leads to the conclusion that when tissue is subjected to gaseous supersaturation, pre-existing gas micronuclei grow into the gas bubbles which are routinely observed in decompression studies. These micronuclei may originate from mechanically induced tribonucleation or cavitation within joints. A new tissue model for decompression sickness based upon failure theory in rubber is proposed. The model shows theoretically that pre-existing sea-level nuclei can be stabilized at depth by elastic forces in tissue. These same elastic forces restrain the growth of nuclei when supersaturation occurs. Mechanical stress will lower the gaseous supersaturation required for growth of nuclei. Gaseous supersaturation, mechanical stress, and the elastic properties of various tissues interact to produce unbounded bubble growth leading to tissue lesions when combined gaseous and mechanical supersaturation exceeds a threshold value. The recommendation is made that the high levels of supersaturation generally used for the decompression of men be reduced.

Animals↗
PubMed2006

Decompression sickness in a swine model: isobaric denitrogenation and perfluorocarbon at depth.

INTRODUCTION: Disabled submarine survivors could achieve inert gas tissue saturation likely to cause severe decompression sickness (DCS) on surfacing. This risk increases with time and depth of exposure. Methods to reduce DCS risk and severity are needed specifically for such an operational scenario. METHODS: Yorkshire swine (16.2-26.6 kg) fitted with an external jugular catheter were compressed to 5 ATA for 22 h. They then received an enriched breathing mix of 44% N2 and 56% O2, and an infusion of either saline or a perfluorocarbon (PFC) emulsion, and were observed for 2 h before surfacing without decompression stops. Controls were surfaced after 22 h saturation at 5 ATA. Surface observations continued for another 2 h on all animals and signs of DCS were recorded to the nearest minute. RESULTS: Seizure activity at depth was noted in 0/26 controls, 1/16 in the saline group, and 7/16 in the PFC group. DCS in < 2 h occurred in 25/26 air controls, 2/15 in the enriched mix/saline group, and 4/9 not suffering seizure in the enriched mix/PFC group. Death in < 2 h occurred in 23/26 controls, 1/15 in the saline group, and 1/9 in the PFC group. DISCUSSION/CONCLUSION: This study demonstrates the benefits of breathing increased O2 at depth prior to rapid decompression and the deleterious effects of PFC administration at depth in a swine saturation model with rapid decompression. Future studies should examine a minimal O2 pre-breathe period to offer protection against DCS as well as the role of PFC use after surfacing.

Animals↗
PubMedDate not supplied

[Probability of altitude decompression sickness during a suited exit from a space ship having a near-Earth atmosphere].

A large number (550) pressure chamber experiments in which 200 suited subjects simulated an egress from the spacecraft (decompression from 760 to 20--10 mm Hg) showed a relationship between decompression sickness frequency and severity, space suit absolute pressure (160--310 mm Hg), time of the exposure (1--10 hours) and desaturation (15--60 min), and exercise load (150--400 Cal/hr). Without desaturation there were no decompression sickness symptoms at a suit pressure of 270--310 mm Hg. An egress into space in a suit at a pressure of 160--230 mm Hg after 15--60 min desaturation induced bends of different severity. Less frequent cases of decompression sickness in our experiments as compared with the literature data (obtained on unsuited subjects) can be attributed to the peculiar kinematics of movements and excessive pressure in the suit.

Adult↗