COPD receiving controlled NPPV aimed at maximal reduction of Paco2
- CP Criée, KL Neuhaus, E Wilhelms
We read with interest the article by Gallagher et al (June 2005)1 comparing cardiorespiratory fitness in patients with morbid obesity vs those with established heart failure. The authors found that obese subjects had maximum oxygen uptake (V̇o2max) values very similar to those of nonobese heart failure subjects. We were surprised to find the published V̇o2max values were expressed in “milliliters per kilogram per minute,” after correction for body weight, rather than the absolute uncorrected V̇o2max (milliliters per minute). For the same absolute value of V̇o2max (milliliters per minute), subjects with greater body mass would have smaller corrected V̇o2max (milliliters per minute per kilogram). In the absence of absolute V̇o2max (milliliters per minute) or body weight data in the published article, it is possible to estimate the surrogate V̇o2max by assuming height was not significantly dissimilar between the groups; thus, multiplying by body mass index can give a rough indication of the V̇o2max of each group (Table 1).