Treatise on aeromedical evacuation: II. Some surgical considerations.

Preventive medicine is the primary responsibility of every physician. When prevention fails and therapeutic measures are required, the initial approach tends to be along a conservative line. When this approach fails, surgical intervention becomes a necessity. Surgical patients, both pre- and post-surgical, may be moved by aircraft providing that one is aware of the hazards in a hostile atmosphere in which pressure and temperature change with increasing altitude. Air or gas trapped in the body cavities expands in direct proportion to the decrease in pressure. This increased volume becomes significant at 5500 m, where the volume of air or gas in the body is doubled. Quite apart form intense discomfort and actual pain caused in certain types of injury, this expansion of gas at high altitude may constitue a real danger, such as in the probability of rupturing a recently sutured intestine and, in cases of pneumothorax, by disturbance of cardiopulmonary dynamics. Thus, aeromedical evacuation of the surgical patient becomes a challenge to those responsible for the medical care between the originating and destination hospitals.