Aviat Space Envir Md
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Aviat Space Envir Md · Feb 1977
Randomized Controlled Trial Clinical TrialEfficient oxygen mask for patients undergoing hyperbaric oxygen therapy.
Hyperbaric oxygen (HBO) is established therapy for various disorders, but its effectiveness depends on the efficiency of the oxygen delivery system. A mask oxygen delivery system, consisting of the standard USAF aviator's A-14 regulator and the MBU-5/P oxygen mask, is installed in all USAF hyperbaric chambers. The efficiency of the mask oxygen delivery system at the USAF Hyperbaric Center, Brooks AFB, Tx, was evaluated breath-by-breath at sea level and 2.4 ATA via two different measuring techniques. ⋯ Inspiratory gas analyses indicate that the USAF aviator MBU-5/P mask and the A-14 regulator as used at the USAF Hyperbaric Center constitute a highly efficient oxygen delivery system for HBO therapy. This view has been refleced in arterial blood gas measurements and in preliminary data from tissue oxygen measurements in a gas gangrene patient. Future improvements in patient therapy masks are recommended.
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Aviat Space Envir Md · May 1976
Case ReportsCerebral air embolism and cerebral edema: one regimen of treatment.
A case of cerebral air embolism responding immediately to compression to 6 atm is described. The patient, however, developed apparent cerebral edema while being decompressed. ⋯ While a number of other medications known to affect intracranial pressure were used, objective clinical improvement was noted only after hyperbaric oxygen. A question is raised of whether there is an association between the development of cerebral edema and the administration of intravenous 5% glucose in water.
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Aviat Space Envir Md · Feb 1976
Pulmonary function evaluation during the Skylab and Apollo-Soyuz missions.
Previous experience during Apollo postflight exercise testing indicated no major changes in pulmonary function. Pulmonary function has been studied in detail following exposure to hypoxic and hyperoxic normal gravity environments, but no previous study has reported on men exposed to an environment that was both normoxic at 258 torr total pressure and at null gravity as encountered in Skylab. Forced vital capacity (FVC) was measured during the preflight and postflight periods of the Skylab 2 mission. ⋯ No major preflight-to-postflight changes were observed. The Apollo-Soyuz Test Project (ASTP) crewmen were studied using equipment and procedures similar to those employed during Skylab 4. Postflight evaluation of the ASTP crewmen was complicated by their inadvertent exposure to nitrogen tetroxide gas fumes upon reentry.
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Nine Caucasian and 13 Bantu young men, all untrained and unacclimated to heat, were tilted head-up for 20 min before and after 4 h of exercise performed at a load of 35 W at room temperature of 23 degrees C and in heat (33.9 degrees C DB, 32.2 degrees C WB). In heat, all Bantu but only four Caucasians completed the 4 h of exposure. The change in systolic blood pressure from recumbency to orthostasis was negligible in the Bantu and adverse in the Caucasians, during pre-exercise tilting at 23 degrees C. ⋯ Seven subjects in each group fainted during heart-orthostatism, and the difference in systolic blood pressure between recumbency and orthostasis in heat was substantially more adverse in the Caucasians. High relationships were found between exercise heart rate, orthostatic heart rate, and fainting episodes. The results suggested that Bantu make better orthostatic adjestments than Caucasians.
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Aviat Space Envir Md · Oct 1975
Comparative StudyAccidental hypothermia: an experimental study of inhalation rewarming.
Inhalation rewarming of hypothermic humans with heated, humidified oxygen was compared to rewarming by immersion in a hot bath. In 10 subjects cooled to approximately 35 degrees C core temperature, there was no significant difference in the amount of temperature "afterdrop" with the two rewarming procedures. ⋯ This method of core rewarming avoids the physiological hazards associated with the peripheral vasodilation which accompanies external rewarming. Moverover the simplicity of application of this method suggests its greater use in both first-aid and hospital treatment of accidental hypothermia.