Potential hazards of high anti-Gz suit protection
Wood, E.H.
Aviation Space and Environmental Medicine 63(11): 1024-1026
1992
ISSN/ISBN: 0095-6562 PMID: 1445154 Document Number: 398975
Although balanced positive pressure breathing increases protection by G suits and reduces fatigue during sustained high G-z exposures, it does not prevent dependent pulmonary right-to-left shunts (arterial hypoxemia) and potentially dangerous distention of nondependent alveoli. An incident of acute incapacitating mediastinal emphysema in a healthy young man during a sustained exposure to 5.5 Gx documents this possibility. This, plus neurogenic bradycardia during sustained high G-z exposures without pressure breathing, suggests that testing of full counterpressure to neck level suits at sustained gt 9 G-z exposures may be hazardous. Fully instrumented studies of animal surrogates with comparable thoracic dimensions are indicated.