EXERCISE CAPACITY AS A PREDICTOR OF POSTOPERATIVE COMPLICATIONS IN LUNG RESECTION CANDIDATES

Exercise testing with measurement of maximal oxygen uptake (VO(2)max) is increasingly used in the assessment of lung resection candidates, b ut its predictive value for postoperative complications remains contro versial. We therefore sought to determine the prognostic value of VO(2 )max compared with other pulmonary function tests. A consecutive group of 80 patients (mean age 61 yr; 57 males and 23 females) scheduled fo r lung resection (62 malignancies, 12 benign disorders, and 6 carcinoi ds) underwent pulmonary function tests and symptom-limited cycle ergom etry. All patients underwent lung resections: 21 pneumonectomies, 45 l obectomies, and 14 segmental or wedge resections. Group A (64 patients , 80%) had an uneventful postoperative course, whereas Group B (16 pat ients, 20%) had complications; 3 of them died (4% overall mortality ra te). In a stepwise logistic regression analysis used to determine inde pendent risk factors for postoperative complications (within 30 d), VO (2)max expressed as a percentage of predicted (84 +/- 19 for Group A v ersus 61 +/- 11 for Group B) proved to be the best predictor (predicti ve value 85.5%). Although VO(2)max expressed in absolute values (ml/kg /min) was also highly predictive (79.5%), a ROC curve analysis proved the percentage predicted values to be significantly more sensitive. Of 9 patients with a VO(2)max < 60% of predicted, 8 had complications, i ncluding all 3 patients who died after resections of more than one lob e (sensitivity 50%, specificity 98%). The estimated probability (probi t model SAS software package) of suffering no complication was 0.9 for VO(2)max > 75% of predicted and 0.1 for a VO(2)max < 43%. We conclude that exercise testing was a valuable tool and VO(2)max expressed as a percentage of predicted was the single best indicator of postoperativ e complications after lung resection. A cutoff value < 60% of predicte d was highly predictive of complications and probably prohibitive for resections involving more than one lobe, whereas a VO(2)max value > 75 % of predicted was an excellent indicator of an uneventful postoperati ve course irrespective of the extent of resection.