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At least 19 recordsLinked to original sources

Adrenal function and the incidence of bends after decompression in mice: effect of adrenalectomy, corticosteroids, decompression intensity, and time of day.

The adrenocortical endocrine subsystem has been demonstrated to enhance mammalian tolerance to harsh environmental conditions, including hypoxia and temperature extremes. In a series of factorial experiments, mice were exposed to one of three elevated hydrostatic pressures for 30 min and then decompressed (0.75 atm/s). It was demonstrated that 1) tolerance to decompression does not differ significantly (P greater than 0.3) in surgically intact, sham adrenalectomized, or in adrenalectomized animals; 2) intraperitoneal administration of pharmacologic doses (0.4, 1.0, and 2.0 mg/mouse) or corticosterone or deoxycorticosterone acetate does not significantly enhance (P greater than 0.1) survivorship when compared to vehicle-injected controls; and 3) the incidence of decompression sickness (DS) does not fluctuate with time of day (P greater than 0.4). In a fourth study, the plasma concentration of corticosterone was quantitated in 1) colony control mice, 2) mice exposed to the 1-ATA chamber environment (chamber control), or 3) mice compressed to 3, 5, 7, 9, or 11 ATA and then decompressed. In general, plasma corticosterone in symptom-free mice was elevated approximately threefold (P less than 0.05) by exposure to the 1-ATA chamber environment and by decompression from 3 to 11 ATA. At 11 ATA, plasma corticosterone levels in decompressed mice exhibiting decompression sickness symptoms were significantly elevated (P less than 0.05) compared to the levels observed in decompressed symptom-free mice. These studies indicate that adrenocortical function does not enhance tolerance to decompression in mice.

Adrenal Cortex Hormones

Intracardial bubbles during decompression to altitude in relation to decompression sickness in man.

Doppler ultrasound was used in five subjects to detect intracardial gas bubbles during decompressions to altitude. At a simulated altitude of 8,000 m, neither intracardial bubbles nor symptoms of decompression sickness occurred. At 9,000 m, bubbles were registered in two subjects, one of which had questionable bends. At 11,500 m, bubbles were registered in all but one subject and two had bends. The three subjects who had not gotten bends were exposed to an air-breathing period of 30 min or, in one case, even 45 min at 2 ATA, for extra nitrogen loading, followed by decompression to 11,500 m. These subjects had heavy showers of bubbles followed by bends. In all cases with decompression sickness during the decompressions to altitude, intracardial bubbles were registered prior to the appearance of symptoms. The technique may be used in studies of decompression sickness without provoking actual symptoms, thus making the studies safer.

Brain Diseases

Decompression sickness and the role of exercise during decompression.

The risk of decompression sickness (DCS) is greatly increased with exercise at altitude. Bends is the commonest symptom in altitude DCS. Though the adverse effect of exercise at altitude is well known, the role of exercise during decompression is not clear. In this paper, a case of bends occurring with exercise during accidental decompression is presented. The event occurred while exercising on a treadmill at an altitude of approximately 4,572 m (15,000 ft) in the hypobaric chamber. No oxygen pre-breathe was done and ambient air was breathed throughout. The role of hypoxia and exercise during decompression, as well as individual susceptibility, are discussed. Even moderately severe exercise at low altitude may predispose healthy individuals breathing ambient air to DCS, especially when exercise is undertaken during decompression.

Adult

Sensory recovery in the plantar aspect of the foot after surgical decompression of posterior tibial nerve. Possible role of steroids along with decompression.

In leprosy, involvement of the posterior tibial nerve leads to sensory loss in the plantar aspect of the foot. As a result plantar ulcers are common and lead to deformity and disability. Restoration of plantar sensation can prevent ulcer formation. Posterior tibial decompression was done for the recovery of sensation in the plantar aspect of the foot. Seventy-two patients under went decompression on 84 feet, 25 received steroids pre- and post-operatively. The recovery of sensation was better if surgery was done before 6 months of onset of anaesthesia. Decompression along with steroids gave better results than decompression alone in patients with active neuritis especially in BT cases whereas in BB, BL and LL cases there was no significant improvement of sensation. The results are discussed.

Adolescent

[Comparative study of decompression-induced formation of gas bubbles using ultrasonic equipment and the development of altitude-decompression disorders].

442 altitude experiments on 40 volunteers were performed. Gas bubbles in venous blood were detected using an ultrasonic Doppler system functioning in a continuous mode at a frequency of 5 MHz. The threshold of bubble formation was identified in 31 test subjects and that of emergency of altitude-decompression disorders, in 28 test subjects. Individual resistance to decompression-induced bubbles was revealed. It was shown that the thresholds may vary with time, in the head-down position and in the head-down position combined with exercises. A correlation was established between the rate of intravascular bubble formation and the frequency of altitude-decompression disorders.

Adult

Does microsurgical vascular decompression for trigeminal neuralgia work through a neo-compressive mechanism? Anatomical-surgical evidence for a decompressive effect.

The positive effect of Microsurgical Vascular Decompression (MVD) on idiopathic trigeminal neuralgia still remains controversial between a decompressive mechanism and a "neo-compressive" one. This paper is a summary of a comparative study of the results on pain obtained with two technical modifications of the MVD procedure. The first consisted of interposition of a foreign material between the nerve and the transposed artery after dissection of the trigeminal nerve, whilst in the second the offending vessel(s) was dislodged without using any material touching the nerve. The two series of 60 patients in each were similar concerning the clinical features. Evaluation of results on neuralgia - with one year follow-up-in both series, shows that the technique used in the second group was not followed by a higher rate of recurrence than the technique used in the first group. On the contrary; 4.5% in the 2nd group compared to 10% in the first. This indicates that MVD would not act as a result of "neo-compression" of the nerve, but rather through a real decompressive mechanism.

Arteries

Medical decompression of toxic megacolon by "rolling". A new technique of decompression with favorable long-term follow-up.

We treated 19 consecutive patients with toxic megacolon complicating inflammatory bowel disease with the usual intensive medical regimen, but also added a new technique, namely, the frequent rolling of the patient to the prone position in order to redistribute colonic gas and thereby promote decompression. In all 19 patients (100%) the colon was decompressed within 1-13 days (mean 4.9 days). Two patients (10.5%) died. In long-term follow-up (mean 6.5 years), only 4 of the 17 survivors (21%) ultimately required colectomy; the remaining 13 (68%) were either completely well or only minimally symptomatic and did not require steroids. Most reports on the management of toxic megacolon stress the need for early surgical intervention, but our success in decompression with the addition of the "rolling technique" suggests an improvement in the nonoperative management of toxic megacolon.

Adult

Degenerative lumbar spondylolisthesis with spinal stenosis. A prospective study comparing decompression with decompression and intertransverse process arthrodesis.

Fifty patients who had spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied clinically and radiographically to determine if concomitant intertransverse-process arthrodesis provided better results than decompressive laminectomy alone. There were thirty-six women and fourteen men. The mean age of the twenty-five patients who had had an arthrodesis was 63.5 years and that of the twenty-five patients who had not had an arthrodesis, sixty-five years. The level of the operation was between the fourth and fifth lumbar vertebrae in forty-one patients and between the third and fourth lumbar vertebrae in nine patients. The patients were followed for a mean of three years (range, 2.4 to four years). In the patients who had had a concomitant arthrodesis, the results were significantly better with respect to relief of pain in the back and lower limbs.

Aged

Hematologic changes in man during decompression: relations to overt decompression sickness and bubble scores.

In order to determine whether asymtomatic gas phase separation causes hematologic abnormalities, studies were carried out following two dive series, one to 210 feet of sea water (FSW) for 50 min and the other to 132 FSW for 30 min. Studies included white and red cell count, red cell indices, platelet count, ESR, fibrinogen, fibrin split products, prothrombin time, partial thromboplastin time, coagulation factors II, V, VII, VIII, and X, clot retraction, platelet aggregation and adhesion, euglobulin lysis time, and platelet factor III. Changes were seen in platelet and white cell count, prothrombin time and partial thrombo-plastin time. White cell count was the only variable which correlated with total bubble score. The results are presented and implications of the findings discussed.

Adult