Rapid decompression of a transport aircraft cabin: protection against hypoxia

The hypoxic hazard after rapid decompression in transport aircraft was evaluated as a function of the current means of protection, including the role of the inhaled oxygen fraction (FIO2) prior to decompression. The decompressions were made in 2 s; the initial altitude was 8,000 ft and the final altitude was 16,000-45,000 ft. The physiological measurements were arterial oxygen saturation, heart rate, ventilatory frequency, and gaseous analysis in the mask. Results show that FIO2 prior to decompression is not very significant, but the delay before donning the oxygen system seems to be the most limiting factor against tolerance to hypoxia.