Respiration and Pulmonary Gas Exchange in Blast Injury

Abstract

Pulmonary ventilation and gas exchange in blast injury were studied in urethane-anesthetized rabbits which had been exposed to high explosive shock waves in a detonation chamber. In slight as well as in severe lung blast injury the respiratory min. vol. usually is considerably increased, and in lethally injured animals the hyperventilation is generally maintained until just before death. The O2 consumption will at first decrease a little, but then it increases gradually except in lethally injured animals, where it is greatly lowered from the very beginning after the exposure. The arterial O2 saturation rapidly declines after the explosion in both slightly and severely injured rabbits but it can, in the early phase, usually be normalized by having the animal breathe pure O2. In slightly injured animals there is an increased CO2 elimination and a shift to alkalinity in the arterial blood. Severe lung blast injury causes a decrease in CO2 elimination and lowering of the blood pH.