Hyperventilation in panic attacks. Ambulant monitoring of transcutaneous carbon dioxide.

Transcutaneous carbon dioxide monitoring has been used to investigate directly the frequency and role of hyperventilation during naturally occurring panic attacks in freely ambulant volunteers and patients. Illustrative preliminary data from healthy subjects and from four patients with panic attacks are presented. These confirm that some patients do hyperventilate during their attacks but indicate that some do not. The unreliability of traditional methods for identifying hyperventilators is demonstrated. These data indicate the potential of ambulant monitoring in research into hyperventilation and panic.