Comparison of estimated and measured maximal oxygen uptake during exercise testing in patients with chronic obstructive pulmonary disease

Abstract

Background: Maximal oxygen uptake (VO(2max)) and exercise modalities such as walking and standard pulmonary function testing are measurements that have been used by the surgical community as an indication of a patient's current exercise capacity to predict operative outcomes. There are equations available in published reports that allow an estimate of VO(2max) to be made by measuring a combination of the distance walked as well as lung function in patients with chronic obstructive -pulmonary disease (COPD).

Aims: The aim of the present study was to determine if estimates of VO(2max) and measured VO(2max) based on predictive equations are useful in individuals with COPD.

Methods: Twenty-eight male patients (mean age 68 years) with a mean forced expiratory volume in 1 s of 1.3 L were enrolled in the study after determining that they could perform a maximal exercise study. The estimated VO(2max) using equations reported by Chuang et al. and Cahalin et al. was cross-validated with the measured VO(2max) determined during cardiopulmonary exercise testing.

Results: The mean estimated VO(2max) using the pre-diction equation did not differ from the mean measured VO(2max) (1.13 vs 1.18 L/min, respectively; P = 0.25). However, the scattered relationship between the measured and the estimated VO(2max) did not support the use of this equation to predict an individual's performance. The prediction equations currently available in published reports significantly underestimate the measured VO(2max) (P < 0.05-10(-12)).

Conclusions: It is recommended that VO(2max) is measured rather than estimated using the prediction equations when a VO(2max) measurement is used for clinical decision-making.