Oxygen uptake efficiency slope in children: Its role in exercise testing

Abstract

Cardiopulmonary exercise testing (CPET) is a useful tool to test the physiological response of the cardiovascular, pulmonary and metabolic systems to exercise. Various parameters have previously been recognised as important to predict prognosis, and many of them show correlations with health outcomes. 1,2 The simplest measures are peak work rate, heart rate (HR) increase during exercise and its decline during the recovery phase. The highest obtained HR during exercise (HR peak) is related to the chronotropic competence of the heart. Especially in children, beyond moderate intensity exercise there is a strong correlation between HR and work rate. The recovery of HR after the cessation of exercise is mainly driven by the parasympathetic part of the autonomic nervous system. 3 In different studies this parameter is strongly related to outcome and prognosis. When a respiratory gas analysis system is available, ventilation (VE), oxygen uptake (VO 2) and carbon dioxide production (VCO 2) can be measured continuously. Subsequently, parameters such as maximal oxygen uptake (VO 2max), VE/ VCO 2 slope and the oxygen uptake efficiency slope (OUES) can be obtained.

New kids on the CPET: age-appropriate outdoor cardiopulmonary exercise testing in preschoolers

“…The oxygen uptake efficiency slope (OUES), an age- and sex-dependent parameter of submaximal cardiopulmonary effort (Bongers et al 2016 ), provides a valid measure of cardiopulmonary fitness in children who cannot reach maximal exertion (Bongers et al 2011 ). As OUES and strongly correlate (Bongers et al 2016 ), the OUES can be used as a surrogate parameter for , especially in study populations, where maximal CPET results are difficult to achieve due to, e.g., motivational issues (Ten Harkel and Takken 2019 ). Furthermore, and OUES show excellent interest reproducibility and reliable results among the same study population (Baba et al 1999 ).…”