Am J Psychiatry 1996; 153:513-518
Copyright © 1996 by American Psychiatric Association
Hyperventilation and panic attacks
B Garssen, M Buikhuisen and R van Dyck
Institute for Research in Extramural Medicine, Vrije Universiteit, Amsterdam, The Netherlands.
OBJECTIVE: Hyperventilation has been posed as an important symptom-
producing mechanism in panic attacks. Some arguments and experimental
findings, such as the possibility of inducing panic symptoms by voluntary
hyperventilation in panic disorder patients, seem to favor this suggestion.
This study was undertaken to clarify the role of hyperventilation in panic
disorder. Long-term ambulatory measurement of transcutaneous arterial CO2
pressure (PCO2) offers an opportunity to test directly the co-occurrence of
panic and hyperventilation under natural conditions. METHOD: Transcutaneous
PCO2 was measured during three to four sessions of approximately 7 hours
each in 28 panic disorder patients. Patients were instructed to expose
themselves to fear-provoking situations and to press a button as soon as
they experienced panic. One-half of the patients experienced one or more
panic attacks during these sessions. RESULTS: A decrease in PCO2 was
observed during only one of the 24 registered panic attacks that lasted at
least 3 minutes. Even during this particular attack, the degree of
hyperventilation was not impressive. CONCLUSIONS: These findings indicate
that the hypothesis that hyperventilation is an important symptom-producing
mechanism in panic may be dismissed.
