A Systematic Review of Reference Values in Pediatric Cardiopulmonary Exercise Testing

Abstract

Cardiopulmonary exercise testing (CPET) is used for the diagnosis and prognosis of cardiovascular and pulmonary conditions in children and adolescents. Several authors have published reference values for pediatric CPET, but evaluation of their validity is lacking. The aim of this study was to review pediatric CPET references values published between 1980 and 2014. We specifically assessed the adequacy of the normalization methods used to adjust for body size. Articles that proposed references values were reviewed. We abstracted information on exercise protocols, CPET measurements and normalization methods. We then evaluated the studies' methodological quality and assessed them for potential biases. Thirty-four studies were included. We found important heterogeneity in the choice of exercise protocols and in the approach to adjustment for body size or other relevant confounding factors. Adjustment for body size was principally done using linear regression for age or weight. Assessment of potential biases (residual association, heteroscedasticity and departure from the normal distribution) was mentioned in only a minority of studies. Our study shows that contemporary pediatric reference values for CPET have been developed based on heterogeneous exercise protocols and variable normalization strategies. Furthermore, assessment of potential bias has been inconsistent and insufficiently described. High-quality reference values with adequate adjustment for confounding variables are needed in order to optimize CPET's specificity and sensitivity to detect abnormal cardiopulmonary response to exercise.

Reference values for cardiopulmonary exercise testing in children and adolescents in northwest Croatia

“…As mentioned here, we found linear increase of minute ventilation during work to peak of 80.03±27.8 L/ min, as a result of linear increase of tidal volume and breathing frequency. As previous fi ndings report that boys reached signifi cantly higher peak VE compared with girls, this is consistent with our fi ndings (27)(28)(29)(30). In correlation with our fi nding at rest, boys had signifi cantly higher lung volumes (29).…”

“…Both girls and boys showed gradual reduction of dead space ventilation during incremental work. Previous studies showed no sex diff erences in breathing frequency increase, VE /VCO2, and end-tidal PCO2 (3,9,(27)(28)(29)(30). The VE/VCO2 slope may represent gas exchange effi ciency during exercise or equivalent of the number of liters of air that must be breathed out to eliminate 1 liter of CO2.…”

Reference values for blood pressure response to cycle ergometry in the first two decades of life: comparison with patients with a repaired coarctation of the aorta

“…These reference values provide a quantitative description of a healthy response to exercise and add to other pediatric exercise testing reference values [17,33]. Clinicians cannot determine an unhealthy response if they do not know what a healthy response is.…”

“…Despite the clinical significance of SBP values for children and its relatively inexpensive way to record them, there is a lack of prevalent normative data. In 2015, a systematic review of all studies that offered reference values of pediatric CPET between 1980 and 2014 was done [17]. Not one of these studies included reference values for SBP.…”

Fitkids Treadmill Test: Age- and Sex-Related Normative Values in Dutch Children and Adolescents

“…18 Various shortcomings of these studies hinder implementation of the protocols in clinical practice.…”