Hyperventilation in flight.

Hyperventilation in flight may be caused by environmental, psychological, pharmacological, and pathological factors. The effects are discussed and two case histories are presented, illustrating the development and effect of hyperventilation in training or aircrew under stress. Investigation of in-flight hyperventilation is technically very difficult, but positive acceleration, hypoglycaemia, and anxiety are important contributory factors. The incidence of hyperventilation must be reduced by educating aircrew in its aetiology, early recognition, and treatment.