Background: The objective of this study was to identify the predictors of underestimation and overestimation of postoperative maximum oxygen consumption (VO(2)max).
Methods: A prospective analysis was performed on 229 patients who had 38 pneumonectomies, 171 lobectomies, and 20 segmentectomies. All patients performed a preoperative and postoperative (on average 9.2 days after surgery) maximal stair-climbing test. Predicted postoperative VO(2)max (ppoVO(2)max) was calculated on the basis of the number of functioning segments removed during operation. The patients were divided into three groups: group A (158 cases), patients with a ppoVO(2)max within 1 standard deviation of the observed postoperative VO(2)max; group B (56 cases), patients with a difference between the observed postoperative VO(2)max and ppoVO(2)max greater than 1 standard deviation (underestimation); and group C (15 cases), patients with a difference between ppoVO(2)max and the observed postoperative VO(2)max greater than 1 standard deviation (overestimation). Univariate and multivariate analyses were performed.
Results: The only significant predictor of underestimation was a high percentage of functional parenchyma removed during operation (p < 0.0001). The significant predictors of overestimation were a low percentage of functional parenchyma removed during operation (p = 0.01) and a high preoperative VO(2)max (p = 0.002).
Conclusions: The prediction of postoperative VO(2)max was not accurate in all patients. Those with a large amount of functional lung tissue removed during operation tended to have a postoperative VO(2)max greater than expected. Conversely, those patients with a small amount of functional lung tissue resected tended to have a postoperative VO(2)max lower than predicted.