1/141. Medical field management of the injured diver. This article discusses the history of medical field management of the injured diver, and presents a comprehensive medical equipment list for field treatment as well as treatment protocols. case reports are used to illustrate the principles and outcome of medical field management. ( info) |
2/141. Three cases of spinal decompression sickness treated by U.S. Navy Treatment Table 7. For patients of type 2 decompression sickness, recompression therapy using U.S. Navy Treatment Table 6 (TT6) and its extensions is the most common means of treatment. However, some cases are resistant to the recompression therapy, and the outcome of TT6 is not always satisfactory. Although a new table, the U.S. Navy Treatment Table 7 (TT7) was described in 1985 in the U.S. Navy diving Manual, to date few cases who were treated using TT7 have been reported. Here, we report three cases of spinal decompression sickness who received treatment according to TT7. Two were sports scuba divers, and the other a commercial diver. TT7 was applied later than 4 d after onset in all three cases; two patients were remarkably improved during the recompression therapy, while the other improved to a certain extent after additional repetitive TT6. Mild impairment of lung function, probably due to pulmonary oxygen toxicity, was observed on lung function testing in one case. In all cases, after additional TT6 and/or rehabilitation, patients were able to return to active daily living. ( info) |
3/141. Hyperbaric chamber-related decompression illness in a patient with asymptomatic pulmonary sarcoidosis. An asymptomatic 46-yr-old male sustained an acute neurologic insult, appearing during the decompression phase of a 50-m dry hyperbaric chamber dive. The right hemisyndrome was most probably related to diving, since symptoms responded rapidly to the early commenced recompression therapy. Further diagnostics revealed a previously unknown pulmonary sarcoidosis with bilateral pulmonary opacities and pleural adhesions that might have predisposed to arterial gas embolism secondary to pulmonary barotrauma. This case may illustrate a potential risk of decompression illness even during dry chamber dives in patients suffering from asymptomatic pleuro-parenchymal pulmonary disease. The value of chest X-ray in the medical assessment of fitness to dive is therefore emphasized. ( info) |
4/141. Cerebral arterial gas embolism in air force ground maintenance crew--a report of two cases. Two cases of cerebral arterial gas embolism (CAGE) occurred after a decompression incident involving five maintenance crew during a cabin leakage system test of a Hercules C-130 aircraft. During the incident, the cabin pressure increased to 8 in Hg (203.2 mm Hg, 27 kPa) above atmospheric pressure causing intense pain in the ears of all the crew inside. The system was rapidly depressurized to ground level. After the incident, one of the crew reported chest discomfort and fatigue. The next morning, he developed a sensation of numbness in the left hand, with persistence of the earlier symptoms. A second crewmember, who only experienced earache and heaviness in the head after the incident, developed retrosternal chest discomfort, restlessness, fatigue and numbness in his left hand the next morning. Both were subsequently referred to a recompression facility 4 d after the incident. Examination by the diving Medical Officer on duty recorded left-sided hemianesthesia and Grade II middle ear barotrauma as the only abnormalities in both cases. Chest x-rays did not reveal any extra-alveolar gas. Diagnoses of Static Neurological Decompression Illness were made and both patients recompressed on a RN 62 table. The first case recovered fully after two treatments, and the second case after one treatment. magnetic resonance imaging (MRI) of the brain and bubble contrast echocardiography performed on the first case 6 mo after the incident were reported to be normal. The second case was lost to follow-up. Decompression illness (DCI) generally occurs in occupational groups such as compressed air workers, divers, aviators, and astronauts. This is believed to be the first report of DCI occurring among aircraft's ground maintenance crew. ( info) |
| decompression sickness (DCS) is a known hazard of altitude chamber operation. The musculoskeletal, dermal, neurological and pulmonary manifestations of DCS are well recognized, but inner ear injury has not been reported. We present the unusual case of a medical corpsman suffering from vestibular DCS after an altitude chamber exposure to 25,000 ft. The patient had a good clinical response to hyperbaric treatment, but there was laboratory evidence of mild residual vestibular damage with full compensation. This case suggests that aviation medical personnel should be more aware of the possible occurrence of inner ear DCS among subjects exposed to altitude. ( info) |
| We report a case of a diver who suffered an episode of maxillary sinus barotrauma that presented with decreased sensation over the cutaneous distribution of the infraorbital nerve after an ascent which produced facial pain and crepitus. This case illustrates a potential confusion between a decompression sickness etiology and a barotraumatic etiology for the observed sensory deficit. The clinical features of this case were most consistent with a barotraumatic etiology for the findings noted. The anatomy of the trigeminal nerve and previous reports of cranial nerve deficits following barotrauma are reviewed. ( info) |
7/141. A trial to determine the risk of decompression sickness after a 40 feet of sea water for 200 minute no-stop air dive. BACKGROUND: The USN93 probabilistic model of decompression sickness (DCS) predicts a DCS risk of 3.9% after a 40 ft of seawater (fsw) for 200 min no-stop air dive, although little data is available to evaluate the accuracy of this prediction. Based on an analysis of Navy safety Center data from diving on U.S. Navy standard air decompression tables, the observed incidence of DCS for this type of dive is 0.11%. Knowing the true incidence of the dive is important for deciding whether or not to adopt proposed probability based decompression procedures for U.S. Navy diving. HYPOTHESIS: The risk of DCS after a 40 fsw for 200 min no-stop air dive is 3.9%. methods: We conducted a closed sequential trial to determine the DCS incidence on this dive. RESULTS: Of 30 military divers who completed 91 dives, there were 2 cases of DCS (2.2%, 95% CI: 0.27 7.7%). The study was terminated early after the second DCS case because of the presence of neurological symptoms and signs. CONCLUSIONS: This study demonstrates that the incidence of DCS in a laboratory setting is higher than observed in fleet diving. Use of the 40 fsw for 200 min schedule in a decompression computer is likely to result in DCS incidence 2.5- to 70-fold greater than that observed in U.S. Navy diving using table-based procedures. ( info) |
8/141. Pulmonary cyst and cerebral arterial gas embolism in a hypobaric chamber: a case report. This is a report of an aircrew member who suffered a serious physiological incident in the form of pulmonary barotrauma and cerebral arterial gas embolism during hypobaric chamber training, and who subsequently was shown to have a cyst in the upper lobe of the left lung. The likely origin of the cyst is discussed, as well as the aeromedical disposition following thoracotomy and apical segmentectomy to remove the cyst. ( info) |
9/141. MRI in decompression illness. We report a case of decompression illness in which the patient developed paraparesis during scuba diving after rapid ascent. MRI of the spine revealed a focal intramedullary lesion consistent with the symptoms. The pathophysiological and radiological aspects of spinal decompression illness are discussed. ( info) |
10/141. Test and evaluation of exercise-enhanced preoxygenation in U-2 operations. BACKGROUND: Preoxygenation to prevent decompression sickness (DCS) during U-2 reconnaissance flights requires considerable time and occasionally does not provide adequate protection. Increasing preoxygenation within a practical period of time provides marginally increased protection and is not always operationally feasible. Including exercise during preoxygenation to increase muscle tissue perfusion, cardiac output, and ventilation can improve the quality of the denitrogenation. methods: A pilot, who reported two cases of DCS during his first 25 U-2 high flights involving cabin altitudes of 29,000-30,000 ft, volunteered to test exercise-enhanced preoxygenation. He performed 10 min of strenuous upper and lower body exercise at the beginning of preoxygenation prior to subsequent high flights without increasing total preoxygenation time. RESULTS: The exercise was performed at 75% of maximal oxygen uptake based on the estimated maximal oxygen uptake determined during an Air Force aerobic fitness test and heart rate. The pilot's next 36 high flights, using exercise-enhanced preoxygenation, were completed with no reports of DCS. CONCLUSIONS: This statistically significant operational test reinforced the laboratory studies. Implementation of this procedure for reducing DCS in susceptible U-2 pilots and collecting additional data from the U-2 pilot population is recommended. ( info) |