Impact of panic attacks on bronchoconstriction and subjective distress in asthma patients with and without panic disorder

© 2017 by the American Psychosomatic Society. Objective: Panic disorder (PD) is common among asthma patients and is associated with worse asthma outcomes. This may occur because of psychophysiological factors or cognitive/affective factors. This study evaluated the impact of panic attacks (PAs) on bronchoconstriction and subjective distress in people who have asthma with and without PD. Methods: A total of 25 asthma patients (15 with PD who had a PA [PD/PA], 10 without PD who did not have a PA [no PD/no PA] ) were recruited from an outpatient clinic. They underwent a panic challenge (one vital capacity inhalation of 35% carbon dioxide [CO 2 ]) and completed the Panic Symptom Scale, the Subjective Distress Visual Analogue Scale, and the Borg Scale before and after CO 2 . Forced expiratory volume in 1 second was assessed pre-and post-CO 2 ; respiratory (i.e., CO 2 production, minute ventilation, tidal volume) was continuously recorded, and physiological measures (i.e., systolic and diastolic blood pressure [SBP/DBP]) were recorded every 2 minutes. Results: Analyses adjusting for age, sex, and provocative concentration of methacholine revealed no significant differences between groups in forced expiratory volume in 1 second change after CO 2 inhalation (F(1, 23) < 0.01, p =.961). However, patients with PD/PA reported more panic (F(1, 22) = 18.10, p < .001), anxiety (F(1, 22) = 21.93, p < .001), worry (F(1, 22) = 26.31, p < .001), and dyspnea (F(1,22) = 4.68, p =.042) and exhibited higher levels of CO 2 production (F(1, 2843) = 5.89, p =.015), minute ventilation (F(1, 2844) = 4.48, p =.034), and tidal volume (F(1, 2844) = 4.62, p =.032) after the CO 2 challenge, compared with patients with no PD/no PA. Conclusions: Results, presented as hypothesis generating, suggest that asthma patients with PD/PA exhibit increased panic-like anxiety, breathlessness, and a respiratory pattern consistent with hyperventilation that was not linked to statistically significant drops in bronchoconstriction.