Factors associated with changes in the 12-m stair-climbing time after lung lobectomy.

ABSTRACT

OBJECTIVE: Postoperative loss-of-exercise capacity is one of the main concerns for patients undergoing lung cancer surgery. This study was designed to identify the factors associated with loss-of-exercise capacity after lobectomy, using an easy surrogate measure: the 12-m stair-climbing time (SCt). METHODS: Ninety-eight patients undergoing lobectomy for suspected stage I lung cancer were prospectively enrolled. SCt and pulmonary function test were evaluated preoperatively as baseline and at 6 months postoperatively. At 6 months postoperatively, 20 patients dropped out. Loss-of-exercise capacity was defined as at least a 3.3% decline (lower quartile) in the estimated maximal oxygen uptake (VO2t 43.06 - 0.4 × SCt). Factors associated with loss-of-exercise capacity were analyzed. RESULTS: Median (interquartile range) baseline SCt was 31.5 (28.2-36.7) s. Baseline SCt was not significantly associated with complications. At 6 months postoperatively, SCt increased by + 4.4 (+ 3.2, + 6.8) s in patients with loss-of-exercise capacity. Sex, smoking status, lobe, procedure, and forced expiratory volume in 1 s showed no significant association with loss-of-exercise capacity. In the multivariable logistic regression, older age (≥ 73 years) (odds ratio 5.25, 95% confidence interval 1.50-18.43, p = 0.010) and lower baseline diffusing capacity of the lung for carbon monoxide (< 75%) (odds ratio 9.23, 95% confidence interval 1.94-43.93, p = 0.005) were significantly associated with loss-of-exercise capacity. CONCLUSION: Age and the baseline diffusing capacity of the lung for carbon monoxide were identified as significant variables associated with variation of exercise capacity after lung cancer surgery, using pre- and postoperative SCt.