[Prediction of postoperative exercise capacity in lung resection candidates]

The relation between submaximal oxygen consumption (MVO2) before and after lung resection was studied, and the possibility to predict postoperative MVO2 was investigated. Thirty four patients (19 lobectomies, 9 bi-lobectomies, 6 pneumonectomies) performed exercise tests one week before operation and at the time when they were able to resume work daily after operation (in two to eleven months). Predicted postoperative MVO2 was calculated from preoperative MVO2 as follows: 0.8 x resection rate x age index x preoperative MVO2 + 183. In this formula the resection rate means [the number of total lung segments--the number of non-working segments]. The age index is 1.5 for patients under 50 years, 1.0 for those between 50 to 69, and 0.8 for those over 70. This predicted MVO2 had strong correlation with actual postoperative MVO2 (r = 0.94, t = 13.4, y = 1.08x - 83) in twenty five patients. Correlation was low in the remaining nine patients, however. The nine had old myocard infarction, postoperative cerebral infarction, marked wet lung, anticancerous chemotherapy within ten days or marked reduced exercise capacity (below 3 METS at maximal exercise). From these results, we concluded it is possible to predict the postoperative MVO2 using preoperative MVO2 except in cases which have some exercise limiting factors or whose exercise capacity is very small.