1/23. 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.- - - - - - - - - - ranking = 1keywords = pressure (Clic here for more details about this article) |
2/23. Radionuclide lung imaging in respiratory decompression sickness: potential role in the diagnosis and evaluation of hyperbaric therapy.Of the more than 3.5 million trained divers in the united states, many will experience various illnesses specific to divers. Most of these illnesses are related to the changes in absolute pressure that divers experience while diving. During and after ascent, a diver is at risk for decompression sickness and pulmonary barotrauma. A very rare casualty is pulmonary decompression sickness from immersion. This is a literature review and case report of a young woman with acute respiratory decompression sickness who had defects on perfusion lung imaging after a diving accident and after hyperbaric oxygen therapy. However, the perfusion defects reverted to normal in less than 24 hours. Possible explanations for the changes in the appearances of the scans are offered and discussed. This case report shows the potential utility of lung scanning in the diagnostic examination of these patients and the evaluation of the adequacy of treatment with hyperbaric oxygen therapy. A greater use of ventilation-perfusion lung scans in the treatment of such patients may establish its role more definitely.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
3/23. Epidemic decompression sickness: case report, literature review, and clinical commentary.BACKGROUND: decompression sickness (DCS) is a syndrome of symptoms caused by bubbles of inert gas. These bubbles are produced by a significant ambient pressure drop. Although cases are usually solitary there have been several episodes of DCS clusters. This paper reports an episode of epidemic decompression sickness and reviews the literature. methods: The case reported describes six aircrewmen with DCS following an unpressurized AC-130 flight (maximum altitude 17,000 ft). Two obvious concerns-the low altitude at which DCS was encountered and the potential for epidemic hysteria-are discussed and discounted. In addition, factors contributing to this case are recounted in depth. Moreover, the literature was examined for similar cases of epidemic decompression sickness. Four other instances were discovered. Detailed qualitative analysis of these five reports was performed. RESULTS: With this information epidemic decompression sickness is defined and classified. Two types are described-individual-based (Epi-I) and population-based (Epi-P). Epi-I is a cluster of DCS following a solitary exposure; whereas, Epi-P is a cluster of DCS following multiple exposures over time. Investigation of Epi-P follows the classical rules of outbreak investigation (time, place, person, and environment); whereas, Epi-I does not. In fact, the focus in Epi-I is almost entirely the environment. Following this outline should produce an etiology that control measures can be directed against. However, it is prudent to look beyond the etiology. Enter the Haddon Matrix, a classic public health tool that considers counter-measures before, during, and after the event. CONCLUSION: These many concepts are illustrated with the presented case. Following this template, both the expert and the novice flight surgeon have a systematic and reproducible approach to these difficult puzzles.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
4/23. altitude decompression sickness in a pilot wearing a pressure suit above 70,000 feet.U-2 pilots are at an increased risk of decompression sickness compared with other aviators in the U.S. Air Force. This is due to the extreme altitudes at which the missions take place. Presented here is a case of decompression sickness that occurred in a U-2 pilot who was wearing a full-pressure suit while flying at an altitude greater than 70,000 ft, with a pressurized cabin altitude of 29,200 ft. This case demonstrates the continued need for pilot education and awareness of DCS risk factors and symptoms.- - - - - - - - - - ranking = 2.5keywords = pressure (Clic here for more details about this article) |
5/23. Should computed chest tomography be recommended in the medical certification of professional divers? A report of three cases with pulmonary air cysts.Pulmonary barotrauma (PBT) is a recognised risk of compressed gas diving. Any reason that causes air trapping in the lung during ascent may cause PBT by increasing intrapulmonary pressure. Chest x ray examination is mandatory for medical certification of the professional divers in many countries, but pulmonary air trapping lesions such as an air cyst in the lungs cannot always be detected by plain chest x ray examination. Computed tomography (CT) is a reliable, but expensive measure for detecting pulmonary abnormalities in divers. Three cases with pulmonary air cysts are reported in which air cysts were invisible on the x ray pictures, but well defined by CT. It is impractical and not cost effective to perform CT for medical certification of all divers, but it can be an option to recommend CT once during the initial examination of the candidates for professional diving, especially if there is a history of predisposing factors, such as smoking or pulmonary infections.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
6/23. Management of herniated intervertebral disks during saturation dives: a case report.During research saturation dives at 5.0 and 5.5 atm abs, 2 divers developed an acute herniation of the nucleus pulposus of the L5-S1 intervertebral disk. In both cases the pain was severe enough to require intravenous morphine or intramuscular meperidine. Although the symptoms presented by these divers are frequently considered to be an indication for immediate surgical consultation, we decided that emergency decompression posed an unacceptable risk that decompression sickness (DCS) would develop in the region of acute inflammation. In both cases strict bedrest and medical therapy were performed at depth. In the first case, 12 h was spent at depth before initiating a standard U.S. Navy saturation decompression schedule with the chamber partial pressure of oxygen elevated to 0.50 atm abs. In the second case, a conservative He-N2-O2 trimix decompression schedule was followed to the surface. In both cases, no initial upward excursion was performed. The required decompression time was 57 h 24 min from 5.5 atm abs and 55 h 38 min from 5.0 atm abs. During the course of decompression, the first diver's neurologic exam improved and he required decreasing amounts of intravenous narcotic; we considered both to be evidence against DCS. The second diver continued to have pain and muscle spasm throughout decompression, however he did not develop motor, reflex, or sphincter abnormalities. Both divers have responded well to nonsurgical therapy.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
7/23. Prevention of work-related decompression illness events by detection of a cardiac right-to-left shunt.A 44-year-old tunnel worker was studied who suffered from several unexplained decompression illness events for almost 15 years. This caisson worker was affected after standard pressure profiles that did not cause symptoms of decompression illness in his colleagues on the same shift. Transesophageal echocardiography revealed an atrial septal defect (grade II) in this otherwise healthy man. Cranial magnetic resonance imaging showed ischemic brain lesions. Among divers, patent foramen ovale, the most common cause of cardiac right-to-left shunts, was shown to increase the risk for decompression illness events by a factor of 4.5 and to double the risk of ischemic brain lesions. Hyperbaric workers with symptoms of unexplained decompression illness, even if they are only slight, should immediately be transferred to a cardiologist so that a cardiac right-to-left shunt will not be overlooked.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
8/23. decompression sickness presenting as a viral syndrome.decompression sickness (DCS) is a well-known hazard of exposure to significant variations in ambient pressure. The diagnosis and management of DCS is frequently a source of confusion. Although the majority of cases are manifested by joint or limb pains (Type I DCS), patients may present with a wide array of symptoms, such as neurologic deficits, headache, fatigue, nausea, and respiratory difficulty. A thorough knowledge of the differential diagnosis and a strong index of suspicion are crucial to the proper management of DCS. Presented herein are two cases of altitude-related DCS which were confused initially with a viral syndrome. A discussion of the symptoms of DCS is included.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
9/23. decompression sickness presenting as optic neuropathy.decompression sickness (DCS) is a systemic disorder caused by an abrupt decrease in the ambient atmospheric pressure to which an individual is exposed. A previously healthy 23-year-old male parachutist developed optic neuropathy after a series of multiple repeated hypobaric exposures; his symptoms improved promptly with recompression and hyperbaric oxygen therapy. We believe this to be the first reported case of DCS presenting as optic neuropathy.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
10/23. Combined arterial gas embolism and decompression sickness following no-stop dives.decompression sickness (DCS) has been clinically classified as Type I (predominantly joint pain) or Type II (predominantly spinal cord lesions). We present 3 cases that are all characterized by severe (Type II) DCS with signs and symptoms of spinal cord injury occurring in conjunction with arterial gas embolism (AGE). We consider the AGE "minor" because only 2 of the 3 subjects initially lost consciousness, and in all cases the signs and symptoms of the AGE had essentially resolved within 1 h or by the time recompression therapy began. DCS was resistant to recompression therapy, even though treatment began promptly after the accident in 2 of the 3 cases. None of the cases had a good neurologic outcome and there has been one death. None of the divers exceeded the U.S. Navy "no-stop" limits for the depths at which they were diving. We have observed a previously unreported clinical syndrome characterized by severe Type II DCS subsequent to AGE following pressure-time exposures that would normally not be expected to produce DCS. We postulate that AGE may have precipitated or predisposed to this form of DCS.- - - - - - - - - - ranking = 0.5keywords = pressure (Clic here for more details about this article) |
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