Exercise capacity assessment in patients undergoing lung resection

BACKGROUND: The value is examined of preoperative functional assessment, including exercise capacity measurement by a cycloergometric maximal exercise test, in the prediction of postoperative cardio-pulmonary complication after lobar resection. METHODS: In a prospective study over a 3-year period, all patients who were candidates for lung resection underwent preoperative functional evaluation by means of resting pulmonary function tests, measurement of the lung diffusing capacity for carbon monoxide and cardio-pulmonary exercise test. Patients who had had pneumonectomy or less than anatomical segmentectomy were excluded. The study population consisted of 73 patients. The postoperative morbidity and mortality record was collected. RESULTS: Sixty-four patients underwent lobectomy, five bilobectomy and four segmentectomy. Indication for surgery was NSCLC in 71 cases. Two postoperative deaths were recorded (2.7%). A pulmonary (n=19) and/or cardiac (n=17) complication was scored in 30 patients (41%). Mean preoperative FEV(1) and VO(2)max of patients who developed pulmonary complications were significantly lower (p=0.013 and p=0.043 respectively) than those of patients without pulmonary complications. Logistic regression analysis found FEV(1) to be an independent factor in pulmonary complication (p=0.002). With regard to pulmonary complication occurrence, the receiver operating characteristic curve showed an area of 0.69 with VO(2)max expressed in ml/kg min and of 0.62 when VO(2)max was expressed as a percentage of the predicted value. The widest point of the curve was found at a VO(2)max value of 18.7 ml/kg min. Six out of the 14 patients (43%) with a preoperative VO(2)max equal to or lower than 15 ml/kg min had a pulmonary complication. No functional preoperative identifiers were found for the 16 patients who presented with postoperative new onset atrial fibrillation. The mean preoperative value of carbon monoxide lung diffusing capacity was significantly lower (p=0.037) in the 30 patients who had postoperative cardio-pulmonary complications than in the complication-free population. CONCLUSIONS: Preoperative exercise capacity assessment helps in stratifying patients at risk for postoperative pulmonary complication. However, it does not appear to be an independent prognostic factor for postoperative outcome.