Descriptors of exertional dyspnea across the COPD severity spectrum

Dyspnea has distinct intensity and qualitative dimensions. We postulated that qualitative descriptors alluding to unsatisfied inspiration (INSP) would reflect critical mechanical constraints, regardless of COPD severity. Aim: To determine if dyspnea quality varied within and between COPD stages and determine the physiological explanations for any differences. Methods: Pulmonary function and symptom-limited cardiopulmonary exercise tests (CPET) were conducted in 266 COPD (73 GOLD 1, 97 GOLD 2, 96 GOLD 3-4) and 94 healthy age-matched control subjects. Dyspnea intensity was measured with the Borg scale and qualitative descriptors were selected from a 15-item questionnaire at end-exercise. Results: Selection frequency of several descriptor phrases was significantly different between COPD and controls but only 2 phrases also tracked COPD severity: “I cannot get enough air in” and “I feel a need for more air.” These phrases clustered together as INSP. INSP was chosen in the top 3 by 57% of COPD and 35% of control subjects (p Conclusion: Dyspnea descriptors pertaining to unsatisfied inspiration discriminated between COPD and health and across COPD severity and were associated with greater restrictive mechanical constraints.