Role of exercise stress testing in preoperative evaluation of patients for lung resection.

Patients with diagnosed or suspected lung cancer first require appropriate staging and proven anatomic resectability. Excellent pre-operative spirometric data (FEV1 > 2.0 L, > 60% predicted) should recommend the patient for surgery immediately without further testing. Those whose preoperative FEV1 is less than 60% predicted or whose DLCO is less than 60% predicted should be sent for quantitative lung scanning to estimate postoperative spirometry and diffusing capacity. Results showing FEV1-PPO and DLCO-PPO greater than 40% of normal suggest an acceptable surgical risk, and the patient should be referred accordingly. Those whose results are less than 40% of predicted should be exercised in some capacity to assess oxygen transport. We believe that cycle ergometry with incremental workloads and the standard monitoring is the best technique available for this (Table 1). Patients with a predicted postoperative FEV1 (or DLCO) greater than 35% of normal values and whose peak exercise VO2 is greater than 15 mL/kg/min should be offered surgery with the goal of removing the smallest volume of tissue that would be compatible with a cure. Those who do not meet these criteria, however, should not be summarily refused surgery if they are willing to accept the possibility of an earlier death or prolonged disability over the certainty of a cancer-related death in the foreseeable months ahead. Because the lung scan prediction of postoperative regional physiology and the exercise test of global oxygen transport examine different aspects of physiologic operability, we would not disagree with anyone who would advocate doing both tests in those at high risk by virtue of spirometric criteria. The logic of this combined approach is illustrated by Figure 1.