Preliminary observations on the effect of hypoxic and hyperbaric stress on pulmonary gas exchange in breath-hold divers.

The article discusses a study which investigated the effect of hypoxic and hyperbaric stress on pulmonary gas exchange in breath-hold divers. Pulmonary diffusing capacity to carbon monoxide (DLCO) and nitric oxide, haemoglobin and haematocrit were estimated in six elite divers. DLCO indicated a relative elevation at two minutes in five subjects and a tendency to drop at 25 minutes compared to pre-dive. The study concluded that an early but transient elevation in DLCO in five divers may reflect the main shift in blood volume during a breath-hold dive.