Comparison of Six-Minute Walk Test and Modified Bruce Treadmill Test in Paediatric Patients With Severe Burns: A Cross-Over Study

Abstract

Objective: To compare the six-minute walk test and the Modified Bruce treadmill test in paediatric patients with severe burns.Subjects: A total of 67 children, aged 7–17 years, with severe burns.Methods: Participants were assigned to randomly perform the six-minute walk test and the Modified Bruce treadmill test on discharge from acute burn care. Primary outcome measure was heart rate. Secondary outcome measures were distance walked, rate of perceived exertion, and maximal oxygen uptake (VO2).Results: A total of 67 participants were enrolled. Thirty-eight patients completed both tests. The mean six-minute walk test maximum heart rate was 135 ± 19 bpm (97–180 bpm) and the mean Modified Bruce treadmill test maximum heart rate was 148 ± 24 bpm (100–197 bpm; p ≤ 0.05), with a weak positive correlation of R² = 0.14. The mean six-minute walk test maximum distance was 966 ± 405 feet (181–1,711 feet) while the mean Modified Bruce treadmill test maximum distance was 1,439 ± 595 feet (175–3,203 feet; p ≤ 0.05), with no correlation of R² = 0.006. The mean rate of perceived exertion score for the six-minute walk test was 3 ± 2.5 (range 0–10) vs a mean rate of perceived exertion score of 10 ± 0 for the Modified Bruce treadmill test.Conclusion: The Modified Bruce treadmill test challenges the cardiorespiratory system significantly more than the six-minute walk test, as reflected by maximum heart rate measurements, and the perception of effort (i.e. rate of perceived exertion) by the patient. When possible, the Modified Bruce treadmill test should be used to assess cardiovascular functional capacity. However, the six-minutewalk test may be more clinically feasible for use with paediatric patients with burns, and provides information about submaximal functional exercise capacity.