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.
