Blood Gas Changes and Hypophosphatemia in Lactate-Induced Panic

Abstract

<h3>To the Editor.—</h3> Gorman et al1 urge that further work be aimed at defining the nature of ventilatory abnormalities in patients with panic disorder (PD) but do not elaborate on the substantial body of work that has already been published in this field. The important association between agoraphobia and hyperventilation (HV)-related complaints has already been established in different populations,^2,3and we have shown that some patients with agoraphobia and PD spend large portions of the waking day in the hypocapnic range (carbon dioxide partial pressure [Pco₂], &lt;30 mm Hg).^4,5For those patients at or close to the threshold for hypocapnia, relatively minor stressors, such as exercise, talking, or even exposure to phobic talk,⁶may provoke sudden reductions in Pco₂that are accompanied by somatic symptoms and panic anxiety. Rapee⁷also demonstrated that patients with PD had not only lower resting end-tidal Pco₂and