Speed of Ascent During Stair Climbing Identifies Operable Lung Resection Candidates

Abstract

Background: Preoperative evaluation of lung resection candidates with impaired pulmonary reserves includes measurement of aerobic capacity. Stair climbing is an attractive low-cost alternative to treadmill exercise testing but it lacks standardisation. Objectives: To directly compare stair climbing and treadmill exercise testing with respect to an established cut-off value for lung resection. Methods: We subjected 56 lung resection candidates to both symptom-limited treadmill exercise testing and stair climbing to a maximum of 20 m. Both exercise tests were monitored with the same portable spiroergometer. Subjects were on average 46.6 years old, 61% were male and 54% had FEV₁/FVC < 70%. Mean FEV₁ and DLCO_c were 51.6 and 57.1%, respectively. Results: Mean altitude reached, exercise time, speed of ascent and peak VO₂ were 16.9 m, 74 s, 14.7 m/min and 22.4 ml/min/kg, respectively, in 54 subjects completing stair climbing. Thirty-one subjects (58%) reached 20 m without stopping. Treadmill tests were completed by 51 subjects and lasted longer (432 s; p < 0.001), but VO_2max was not different compared to stair climbing (22.7 ml/min/kg; p = 0.673). Speed of ascent was significantly correlated to both stair climbing peak VO₂ (r = 0.63) and treadmill VO_2max (r = 0.67). All 19 subjects (34%) who reached 20 m in 80 s or less (≥15 m/min) had a VO_2max of ≥20 ml/min/kg. Conclusions: We found a clinically useful correlation between speed of ascent during stair climbing and VO_2max during treadmill exercise testing. Climbing to 20 m with an average speed of ascent of ≥15 m/min accurately identified subjects qualifying for pneumonectomy according to established criteria.