Treadmill Testing of Children Who Have Spina Bifida and Are Ambulatory: Does Peak Oxygen Uptake Reflect Maximum Oxygen Uptake?

摘要

Earlier studies have demonstrated low peak oxygen uptake (Vo^sub 2^peak) in children with spina bifida. Low peak heart rate and low peak respiratory exchange ratio in these studies raised questions regarding the true maximal character of Vo^sub 2^peak values obtained with treadmill testing. The aim of this study was to determine whether the Vo^sub 2^peak measured during an incremental treadmill test is a true reflection of the maximum oxygen uptake (Vo^sub 2^max) in children who have spina bifida and are ambulatory. A cross-sectional design was used for this study. Twenty children who had spina bifida and were ambulatory participated. The Vo^sub 2^peak was measured during a graded treadmill exercise test. The validity of Vo^sub 2^peak measurements was evaluated by use of previously described guidelines for maximum exercise testing in children who are healthy, as well as differences between Vo^sub 2^peak and Vo^sub 2^ during a supramaximal protocol (Vo^sub 2^supramaximal). The average values for Vo^sub 2^peak and normalized Vo^sub 2^peak were, respectively, 1.23 L/min (SD=0.6) and 34.1 mL/kg/min (SD=8.3). Fifteen children met at least 2 of the 3 previously described criteria; one child failed to meet any criteria. Although there were no significant differences between Vo^sub 2^peak and Vo^sub 2^supramaximal, 5 children did show improvement during supramaximal testing. These results apply to children who have spina bifida and are at least community ambulatory. The Vo^sub 2^peak measured during an incremental treadmill test seems to reflect the true Vo^sub 2^max in children who have spina bifida and are ambulatory, validating the use of a treadmill test for these children. When confirmation of maximal effort is needed, the addition of supramaximal testing of children with disability is an easy and well-tolerated method.