Multidimensional breathlessness assessment during cardiopulmonary exercise testing in healthy adults

Purpose This study explored if healthy adults could discriminate between different breathlessness dimensions when rated immediately one after another (successively) during symptom-limited incremental cardiopulmonary cycle exercise testing (CPET) using multiple single-item rating scales. Methods Fifteen apparently healthy adults (60% male) aged 22 ± 2 years performed six incremental cycle CPETs separated by ≥ 48 h. During each CPET (at rest, every 2-min and at end exercise), participants rated different breathlessness sensations using the 0–10 modified Borg scale using one of six assessment protocols, randomized for order: (1) ‘BREATHLESS ALL ’ = breathlessness sensory intensity (SI), breathlessness unpleasantness (UN), work/effort of breathing (SQ W/E ), and unsatisfied inspiration (SQ UI ) assessed; (2) SI and UN assessed; and (3–6) SI, UN, SQ W/E , and SQ UI each assessed alone. Physiological responses to CPET were also evaluated. Results Physiological and breathlessness responses to CPET were comparable across the six protocols, with the exception of SI rated lower at the highest submaximal power output (220 ± 56 watts) during the BREATHLESS ALL protocol (0–10 Borg units 4.2 ± 1.7) compared to SI + UN (5.2 ± 2.1, p = 0.03) and SI alone (5.1 ± 1.9, p = 0.04) protocols. Ratings of SI and SQ W/E were not significantly different when assessed in the same protocol, and were significantly higher than UN and SQ UI , which were comparable. Conclusion In healthy younger adults, use of two separate single-item rating scales to assess breathlessness during CPET is feasible and enables the distinct sensory intensity and affective dimensions of exertional breathlessness to be assessed.