Aeromedical Issues Related to Positive Pressure Breathing for +Gz Protection

摘要

Positive pressure breathing as a method to enhance aircrew tolerance for repeatedand sustained high +G, exposures (PBG) was first considered many years ago. Use of Combined Advanced Technology Enhanced Design G Ensemble (COMBAT EDGE) as a G-protection measure increases overall tolerance to +Gz acceleration by reducing the fatigue associated with performing straining maneuvers during extended or repeated exposures to acceleration stress. Physiologically, PBG exerts its effects upon both the cardiovascular and respiratory systems. The principal benefit of PBG is the maintenance of elevated intrathoracic pressure with minimal voluntary effort on behalf of the individual. Some confusion exists with regard to the potential impact COMBAT EDGE may have on the physical health of aircrew. A certain unknown probability exists suggesting acute and/or long-term exposure to PBG may produce certain undesirable changes in the cardiopulmonary physiology of a pilot. This issue has resulted in the need to provide information regarding the current state of our understanding. Described herein are the principal physiologic issues raised concerning use of COMBAT EDGE, looking to the available literature, past experience, and current and future research answers. Positive pressure breathing, G-Protection, Aerospace medicine.