Hyperventilation and panic attacks in general hospital patients.

The 2-week prevalence of panic attacks according to DSM-III-R criteria was assessed in 102 general hospital patients with unexplained somatic symptoms suggestive of the hyperventilation syndrome (HVS). Thirty-six patients were classified as panickers. In comparison to nonpanickers, panickers reported more severe panic and hyperventilation symptoms and state anxiety during anxiety episodes in daily life and also obtained higher scores on measures for depression, generalized anxiety, agoraphobic anxiety, and agoraphobic avoidance. During the Hyperventilation Provocation Test, panickers reported more panic and hyperventilation symptoms and state anxiety and also rated their symptoms to be more similar to those occurring in daily life than nonpanickers. However, no differences were observed between panickers and nonpanickers in base excess values or in minute respiratory volume, respiratory rate, or fraction of end-tidal carbon dioxide during the resting, hyperventilation, and recovery phase. It is concluded that the prevalence of panic attacks in this group of patients is relatively high and that medical specialists must be more attentive to the occurrence of panic attacks or panic disorder in general hospital patients with unexplained somatic symptoms suggestive of HVS.