Estimation of Ventilatory Reserve by Stair Climbing

Clinicians and surgeons have used the subjective response to the climb of “one or two flights of stairs” to assess the “reserve” of patients with chronic airflow obstruction (CAO). Very little objective data exist regarding the metabolic and ventilatory cost for any level of stair climbing in these patients. Therefore, this study was designed to evaluate the use of symptom-limited stair climbing as a simple method to estimate the peak oxygen uptake ( V˙o2) and minute ventilation ( V˙E) in patients with CAO. We studied 31 men with varying degrees of CAO, who climbed stairs until they stopped at their symptom-limited maximum. During this climb, timed expired gas was intermittently collected and analyzed, and oxygen saturation and heart and respiratory rates were recorded. The patients achieved 81 ± 14 percent of their predicted maximal heart rate and 90±27 percent of their predicted maximal V˙E. The number of steps or flights climbed correlated linearly with peak V˙o2 (r=0.72, p