Psychological triggers and hyperventilation symptoms in asthma

Background Anecdotal accounts have identified hyperventilation as one route through which psychological factors can trigger bronchoconstriction. However, little is known about the empirical association between psychological and other trigger factors and hyperventilation in asthma exacerbations. Objective To study the cross-sectional association between perceived triggers and hyperventilation symptoms in 1 British and 1 German sample of patients with asthma who were recruited from the community and from primary care clinics. Method Patients completed relevant language versions of the Asthma Trigger Inventory and the Asthma Symptom Checklist. Results After controlling for demographics and asthma severity, perceived asthma triggers measured by subscales of the Asthma Trigger Inventory explained 12.5% to 37.3% of the variance in Asthma Symptom Checklist hyperventilation-hypocapnia symptoms. Psychological triggers accounted for 10.6% to 26.7% of the variance alone and 4.3% to 11.0% of the variance over and above other trigger factors. In contrast, perceived animal and pollen allergen triggers did not contribute unique variance to the hyperventilation symptom report. Psychological triggers did not explain variance in classic airway obstruction symptoms, thus arguing against a general bias toward inflated symptom reports in patients with psychologically induced asthma. Conclusion Differences in perceived asthma triggers are substantially associated with hyperventilation symptoms, and patients with more frequent psychological triggers also tend to report that they experience more hyperventilation symptoms during their asthma symptom episodes.