Predicting Postoperative Pulmonary

tween July 1991 and March 1994 and who underwent lung resection. The predicted postoperative FEVi and FVC were calculated based on the number of segments resected and were compared with the actual postoper¬ ative FEVi and FVC. Setting: This study was conducted at a university, tertiary referral hospital. Patients: All patients were evaluated at a multidisci¬ plinary lung cancer clinic and underwent lung resection by one surgeon (L.A.L.). Measurements and main results: Sixty patients under¬ going 62 pulmonary resections were reviewed. The pre¬ dicted postoperative FEVi and FVC were calculated using the following formula: predicted postoperative FEVi (or FVC)=preoperative FEVi (or FVC)X(1-(SX 0.0526)); where S=number of segments resected. The actual postoperative FEVi and FVC correlated well with the predicted postoperative FEVi and FVC for patients undergoing lobectomy (r=0.867 and r=0.832, respectively); however, the predicted postoperative FEVi consistently underestimated the actual postoper¬ ative FEVi by approximately 250 mL. For patients un¬ dergoing pneumonectomy, the actual postoperative FEVi and FVC did not correlate as well with the predicted postoperative FEVi and FVC (r=0.677 and r=0.741, respectively). Although there was considerable variability, the predicted postoperative FEVi consis¬ tently underestimated the actual postoperative FEVi by nearly 500 mL. Of the patients undergoing lobectomy, eight also received postoperative radiation therapy. When analyzed separately, patients receiving combined therapy lost an average of 5.47% of FEVi per segment resected. This contrasts with a 2.84% per segment reduction in FEVi for patients who did not receive ra¬ diation therapy. Conclusions: This simple calculation of predicted post¬ operative FEVi and FVC correlates well with the actual postoperative FEVi and FVC in patients undergoing lobectomy. The predicted postoperative FEVi consis¬ tently underestimated the actual postoperative FEVi by approximately 250 mL. The postoperative FEVi and FVC for patients undergoing pneumonectomy is not accurately predicted using this equation. The predicted postoperative FEVi for patients undergoing pneumo¬ nectomy was underestimated by an average of 500 mL and by greater than 250 mL in 12 of our 13 patients. Thus, by adding 250 mL to the above calculation of predicted postoperative FEVi, we improve our ability to estimate FEVi for patients undergoing lobectomy and