Chest
Volume 129, Issue 4, April 2006, Pages 863-872
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Original Research
Effect of Lung Resection on Exercise Capacity and on Carbon Monoxide Diffusing Capacity During Exercise

https://doi.org/10.1378/chest.129.4.863Get rights and content

Objective

To evaluate the effect of lung resection on lung function and exercise capacity values, including diffusion capacity of the lung for carbon monoxide (Dlco), during exercise, and to determine whether postoperative lung function, including exercise capacity and Dlco during exercise, could be predicted from preoperative lung function and the number of functional segments resected.

Design

Prospective study.

Setting

Clinical pulmonary function laboratory in a university teaching hospital.

Patients

Twenty-eight patients undergoing lung resection at Vancouver General Hospital from October 1998 to May 1999, were studied preoperatively and 1-year postoperatively.

Interventions

We determined FEV1 and FVC, and maximal oxygen uptake (Vo2max) and maximal workload (Wmax) achieved during incremental exercise testing. We used the three-equation modification of the single-breath Dlco technique to determine Dlco at rest (RDlco) and during steady-state exercise at 70% of Wmax, and the increase in Dlco from rest to exercise (ie, the mean increase in Dlco percent predicted at 70% of Wmax from resting Dlco percent predicted [(70%-R)Dlco]). We calculated the predicted postoperative (PPO) values for all the above parameters using the preoperative test data and the extent of functioning bronchopulmonary segments resected, and compared the results with the actual 1-year postoperative results.

Results

Following lung resection, there was a significant reduction in FEV1, FVC, and Dlco with decreases of 12%, 13%, and 22% predicted, respectively. There were also significant decreases in Vo2max per kilogram of 2.1 mL/min/kg (8% of predicted Vo2max) and in Wmax of 12 W (7% of predicted Wmax). However, (70%-R)Dlco did not significantly decrease after lobectomy but decreased after pneumonectomy. The calculated PPO values significantly underestimated postoperative values after pneumonectomy but were acceptable for lobectomy.

Conclusions

Exercise tests may be better indicators of functional capacity after lung resection than measurements of FEV1 and FVC or RDlco. PPO results calculated by estimating the functional contribution of the resected segments, are comparable with those obtained using ventilation-perfusion lung scanning and significantly underestimate postoperative lung function after pneumonectomy, but are acceptable for lobectomy.

Section snippets

Materials and Methods

In our previous study,9 a total of 57 patients with non-small cell lung cancer undergoing thoracotomy for lung resection at Vancouver General Hospital from October 1998 to May 1999 were evaluated preoperatively. The study was approved by the University of British Columbia Ethics Review Board, and all patients signed an informed consent form prior to participation.

Details of the lung function tests and exercise studies have been described previously.9 A computerized dry rolling seal spirometer

Results

The 28 patients who had undergone follow-up studies 1 year after undergoing lung resection had a mean (± SD) age of 64.6 ± 10 years; 17 patients (61%) were men, and 11 patients (39%) were women. The mean height was 168 ± 10 cm, and the mean weight was 71 ± 14 kg. The surgical interventions that had been performed were pneumonectomy (5 patients), lobectomy (19 patients), and segmental resection (4 patients). Preoperative data on these 28 patients are shown in Table 1 and are similar to those of

Discussion

The main findings in this study were as follows: (1) the increase in Dlco with exercise was preserved after lobectomy; and (2) the calculation of PPO values for lung function and exercise test results from preoperative test data and the extent of functioning of the resected bronchopulmonary segments yielded acceptable results after lobectomy. Although there was a slight decrease in maximal exercise capacity after lobectomy, there was preservation of the (70%-R)Dlco after lobectomy, indicating

Acknowledgment

The authors thank Drs. Kenneth Evans and Richard Finley for their cooperation in recruiting their patients for the study; Drs. Brian Graham, Jim Potts, and Sundeep Rai for their advice and help in setting up the 3EQ-Dlco technique; Dr. Sverre Vedal for supervising some of the exercise tests and for helpful advice; Dr. Harry Joe for his help with the statistical analysis and graphic presentation of data; and the Lung Function Staff for their help in recruiting patients.

References (21)

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Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).

Dr. Wang was supported in part by a Fellowship from the British Columbia Lung Association and by funds from the Vancouver General Hospital Foundation. The analyzers and computer for the 3EQ-Dlco were obtained through a grant from the British Columbia Medical Services Foundation, while the SensorMedics exercise equipment was purchased with a major equipment grant from the Tuberculosis and Chest Disabled Veterans Association.

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