The inaccuracy of LaFarge equations estimating the oxygen consumption in children under 3 years age

Abstract

Abstract Accurate oxygen consumption measurement (VO2), is essential to obtain a reliable hemodynamic assessment, particularly in patients with congenital heart diseases undergoing cardiac catheterization. LaFarge equations can be unreliable in predicting VO2, particularly in the pediatric population. In a clinical setting, these inaccurate estimates can lead to important hemodynamic parameter miscalculations, with possible therapeutic or diagnostic consequences. Our aim is to validate LaFarge equations (the most widely used for estimating VO2) and compare them with direct measurement in children during cardiac catheterization in the cath lab. We performed a prospective observational study in 21 patients (0–3 years of age) with different congenital cardiac diseases, scheduled for diagnostic cardiac catheterization. Under general anesthesia and mechanical ventilation, VO2 was measured directly with a metabolic module in our cath lab, and also estimated using LaFarge equations. Statistical analysis included Bland-Altman plots, Pearson coefficient and percentage error, among others. LaFarge equations overestimated VO2 values in all study patients. Therefore, in pediatric patients under 3 years of age, the use of direct VO2 measurement methods are more accurate and acceptable than LaFarge equations.