Cardiopulmonary exercise testing in children - An individualized protocol for workload increase

Objectives: To investigate the feasibility of individualized workload increments, as used in adults, for exercise testing in children; and to investigate whether this individualized protocol makes it possible to satisfy the usual criteria for maximal exercise (clinical exhaustion, predicted maximum heart rate [HRmax], oxygen uptake [Vo(2)]plateau, maximal respiratory exchange ratio > 1.1). Design: Prospective clinical study. Setting: Pediatric exercise testing laboratory. Subjects: Ninety-two children aged 3 to 17 years with various cardiac and respiratory diseases (33 with asthma, 11 with bronchopulmonary dysplasia, 6 with cystic fibrosis, 10 with congenital heart disease, and 32 miscellaneous). Interventions: Individualized maximal incremental exercise testing. The increase in workload was adapted to the individual and was calculated fr om predicted maximal oxygen uptake (iio,max) for each child. The test lasted 10 to 12 min. Results: The exercise test was well tolerated by all children and was maximal in all but seven patients. A total of 65.7% of children reached the predicted Vo(2)max and 68.1% satisfied the criteria for a Vo(2), plateau at peak exercise. The predicted HRmax was achieved in all but two children. The mean maximal respiratory exchange ratio was 1.06, Conclusion: The individualized protocol for increasing workload, based on Vo(2), rather than power, was well tolerated by children. In our view, the best two criteria for assessing the maximality of the tests were clinical exhaustion and HRmax, especially if the Vo(2), plateau was not reached. These results suggest that individualized protocols could be used instead of standardized tests for exercise testing in children.