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Evaluation of medical treatments to increase survival of ebullism in guinea pigsSpaceflight carriers run a constant risk of exposure to vacuum. Above 63,000 ft (47 mmHg), the ambient pressure falls below the vapor pressure of water at 37 C, and tissue vaporization (ebullism) begins. Little is know about appropriate resuscitative protocols after such an ebullism exposure. This study identified injury patterns and mortality rates associated with ebullism while verifying effectiveness of traditional pulmonary resuscitative techniques. Male Hartley guinea pigs were exposed to 87,000 ft for periods of 40 to 115 sec. After descent, those animals that did not breathe spontaneously were given artificial ventilation by bag and mask for up to 15 minutes. Those animals surviving were randomly assigned to one of three treatment groups--hyperbaric oxygen (HBO), ground-level oxygen (GLO2), and ground-level air (GLAIR). The HBO group was treated on a standard treatment table 6A while the GLO2 animals received O2 for an equivalent length of time. Those animals in the GLAIR group were observed only. All surviving animals were humanely sacrified at 48 hours. Inflation of the animal's lungs after the exposure was found to be difficult and, at times, impossible. This may be due to surfactant disruption at the alveolar lining. Electron microscopy identified a disruption of the surfactant layer in animals that did not survive initial exposure. Mortality was found to increase with exposure time: 40 sec--0 percent; 60 sec--6 percent; 70 sec--40 percent; 80 sec--13 percent; 100 sec--38 percent; 110 sec--40 percent; and 115 sec--100 percent. There was no difference in the delayed mortality among the treatment groups (HBO--15 percent, GLO2--11 percent, GLAIR--11 percent). However, since resuscitation was ineffective, the effectiveness of any post-exposure treatment was severely limited. Preliminary results indicate that reuscitation of guinea pigs following ebullism exposure is difficult, and that current techniques (such as traditional CPR) may not be appropriate.
Document ID
19940007076
Document Type
Conference Paper
Authors
Stegmann, Barbara J. (Hyperbaric Medicine San Antonio, TX, United States)
Pilmanis, Andrew A. (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Wolf, E. G. (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Derion, Toniann (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Fanton, J. W. (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Davis, H. (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Kemper, G. B. (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Scoggins, Terrell E. (Aerospace Medical Research Labs. Brooks AFB, TX., United States)
Date Acquired
September 6, 2013
Publication Date
February 1, 1993
Publication Information
Publication: NASA. Johnson Space Center, Sixth Annual Workshop on Space Operations Applications and Research (SOAR 1992), Volume 2
Subject Category
LIFE SCIENCES (GENERAL)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19940007055Analytic PrimarySixth Annual Workshop on Space Operations Applications and Research (SOAR 1992), volume 2