Stair climbing in the functional assessment of lung resection candidates

Background: Algorithms for the pre-operative evaluation of lung resection candidates with impaired lung function invariably include maximum oxygen uptake (VO(2)MAX) as a critical parameter of functional reserves, with a VO(2)MAX >or=20 ml/kg/min generally considered sufficient for pneumonectomy. Stair climbing is a low-cost alternative to assess exercise capacity.

Objectives: As stair climbing is not standardised, we aimed to compare the altitude reached and the speed of ascent with VO(2)MAX measured by cycle ergometry.

Methods: We prospectively enrolled 44 pulmonary resection candidates (mean age: 47.6 +/- 12.5 years) with an FEV(1) <80%. Patients were asked to climb as high and as fast as they could, to a maximum elevation of 20 m. The altitude reached and the average speed of ascent were compared to VO(2)MAX.

Results: Forty-three patients reached a 20-metre elevation. Thirteen of them, as well as the patient who did not reach this height, had a VO(2)MAX <20 ml/kg/min. There was a linear correlation between speed of ascent and VO(2)MAX/kg (R(2) = 0.67), but not between altitude and VO(2)MAX/kg. All 24 patients with a speed >or=15 m/min had a VO(2)MAX >or=20 ml/kg/min. Thirty-nine of 40 patients with a speed >or=12 m/min had a VO(2)MAX >or=15 ml/kg/min.

Conclusions: The average speed of ascent during stair climbing was an accurate semiquantitative predictor of VO(2)MAX/kg, whereas altitude was not. We were able to identify potential cut-off values for lobectomy or pneumonectomy. Pending validation with clinical endpoints, stair climbing may replace formal exercise testing at much lower costs in a large proportion of lung resection candidates.