2004 OPEN FORUM Abstracts
EFFECT OF LUNG RESECTION ON CO DIFFUSING CAPACITY DURING EXERCISE
Jeng-Shing Wang MD, MSc, FCCP
Section of Chest Medicine, E-Da Hospital & I-Shou University, Kaohsiung, Taiwan
Background: The purpose of this prospective study is to predict postoperative lung function and exercise capacity values including DLCO during exercise, and to evaluate the effect of lung resection on lung function and exercise capacity values including DLCO during exercise after one year.
Methods:Fifty-seven patients undergoing lung resection at Vancouver General Hospital from October 1998 to May 1999.Lung function including FEV1 and FVC, and exercise capacity including maximal oxygen uptake (VO2max/kg) and maximal workload (Wmax) were obtained by routine procedure. We used a modification of the single breath DLCO technique, the 3-equation method (3EQ-DLCO), to determine DLCO during rest and during steady state exercise at 70% of the maximal workload reached in a progressive exercise test, and the increase in 3EQ-DLCO during exercise, (70%-R)DLCO%, was determined. Calculation of the predicted postoperative (ppo) variables were performed using preoperative testing data and the extent of resected bronchopulmonary segments. All function variables were collected from 30 patients again after lung resection.
Results: The ppo values from the calculation were lower than but not significantly different from actual postoperative values. Following lung resection, there was a more significant reduction in lung function including FEV1, FVC, and DLCO (12%, 13%, and 22%) than that in exercise capacity including VO2max/kg and Wmax (2.1 ml/min/kg (or VO2max 8%) and 12watts (or 7%)). But the postoperative DLCO increase during exercise was not significantly decreased (2%).
Conclusions: This study confirms that postoperative lung function were significantly decreased, but (70%-R)DLCO% was not significantly decreased. These findings suggested that exercise capacity, especially (70%-R)DLCO%, is more conservative and accurate for preoperative evaluation and postoperative prediction.