How accurately can we predict forced expiratory volume in one second after major pulmonary resection?

Standard formulas for predicting postoperative forced expiratory volume in 1 second (po-FEV1) do not consider bronchi obstructed by tumor or chronic obstructive pulmonary disease, e.g., Formula 1 [ppo-FEV1 = (pre-opFEV,) x (# segments remaining)/(# of total segments)] whereas Formula 2 [ppo-FEV1 = (pre-opFEV,) x (# segments remaining)/(# of total unobstructed segments)] does. A retrospective chart review was conducted to determine accuracy of predicting po-FEV1, at a comprehensive cancer center. Predicted po-FEV, was calculated using different formulas and analyzed using regression analysis and Pearson correlation. We found good correlation between po-FEV1 and predicted po-FEV1 using Formulas 1 and 2. In patients with tumor airway obstruction or chronic obstructive pulmonary disease, predictive accuracy decreased for both formulas. Prediction of FEV1 in patients undergoing pulmonary resection was generally accurate, but major errors were observed in some cases; therefore, better predictive formulas are needed in patients with airway obstruction by tumor or chronic obstructive pulmonary disease.