Peak Oxygen Consumption Measured during the Stair-Climbing Test in Lung Resection Candidates

Abstract

Background: The stair-climbing test is commonly used in the preoperative evaluation of lung resection candidates, but it is difficult to standardize and provides little physiologic information on the performance. Objective: To verify the association between the altitude and the VO_2peak measured during the stair-climbing test. Methods: 109 consecutive candidates for lung resection performed a symptom-limited stair-climbing test with direct breath-by-breath measurement of VO_2peak by a portable gas analyzer. Stepwise logistic regression and bootstrap analyses were used to verify the association of several perioperative variables with a VO_2peak <15 ml/kg/min. Subsequently, multiple regression analysis was also performed to develop an equation to estimate VO_2peak from stair-climbing parameters and other patient-related variables. Results: 56% of patients climbing <14 m had a VO_2peak <15 ml/kg/min, whereas 98% of those climbing >22 m had a VO_2peak >15 ml/kg/min. The altitude reached at stair-climbing test resulted in the only significant predictor of a VO_2peak <15 ml/kg/min after logistic regression analysis. Multiple regression analysis yielded an equation to estimate VO_2peak factoring altitude (p < 0.0001), speed of ascent (p = 0.005) and body mass index (p = 0.0008). Conclusions: There was an association between altitude and VO_2peak measured during the stair-climbing test. Most of the patients climbing more than 22 m are able to generate high values of VO_2peak and can proceed to surgery without any additional tests. All others need to be referred for a formal cardiopulmonary exercise test. In addition, we were able to generate an equation to estimate VO_2peak, which could assist in streamlining the preoperative workup and could be used across different settings to standardize this test.