Oxygen uptake kinetics during cardiopulmonary exercise testing and postoperative complications in patients with lung cancer

Abstract

It is accepted that cardiopulmonary exercise testing is one of the most valuable parameters, especially peak oxygen uptake (VO 2), for the evaluation of risk assessment in lung cancer surgery. It therefore represents an attractive way of identifying a patient at high risk for postoperative complications. However, many patients do not achieve the maximal or predictive level during an incremental exercise testing. The purpose of the current investigation was to study the value of the oxygen uptake efficiency slope (OUES), which shows exercise capacity during submaximal testing, in predicting postoperative mortality in patients with bronchogenic carcinoma scheduled for lung resection. Forty-nine patients with bronchogenic carcinoma participated in studies with exercise tests as a preoperative evaluation. The peak VO 2 was calculated for each subject by averaging values obtained during the final 10 s of exercise. The following equation was used to determine OUES: VO 2/log 10 VE. Peak VO 2 without postoperative complication was 22.8 ± 3.3 ml/(kg min), however, peak VO 2 in patients with present complications was 19.1 ± 4.2 ml/(kg min) ( p = 0.001). In addition, although the mean OUES in patients with present complications was 11.1 ± 1.2, the mean OUES in the absent group was 13.3 ± 2.1 ( p < 0.001). Although peak VO 2 is useful in evaluating selected patients with bronchogenic carcinoma, OUES is also a beneficial parameter and should be calculated and recorded with peak VO 2, a better predictor of poor surgical outcome than absolute values, and should be integrated into preoperative decision making.