Stair climbing in the functional assessment of lung resection candidates

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.

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.

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.

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.

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.