Measured Oxygen Consumption During Pediatric Cardiac Catheterization is More Accurate than Assumed Oxygen Consumption

Document Type

Journal Article

Publication Date



Pediatric cardiology




Cardiac output; Congenital heart defects; Hemodynamic monitoring; Indirect calorimetry


When calculating cardiac index (C.I.) by the Fick method, oxygen consumption (VO) is often unknown, so assumed values are typically used. This practice introduces a known source of inaccuracy into the calculation. Using a measured VO (mVO) from the CARESCAPE E-sCAiOVX module provides an alternative that may improve accuracy of C.I. calculations. Our aim is to validate this measurement in a general pediatric catheterization population and compare its accuracy with assumed VO (aVO). mVO was recorded for all patients undergoing cardiac catheterization with general anesthesia and controlled ventilation during the study period. mVO was compared to the reference VO (refVO) determined by the reverse Fick method using cardiac MRI (cMRI) or thermodilution (TD) as a reference standard for measurement of C.I. when available. 193 VO measurements were obtained, including 71 with a corresponding cMRI or TD measure of cardiac index for validation. mVO demonstrated satisfactory concordance and correlation with the TD- or cMRI-derived refVO (ρ = 0.73, r = 0.63) with a mean bias of - 3.2% (SD ± 17.3%). Assumed VO demonstrated much weaker concordance and correlation with refVO (ρ = 0.28, r = 0.31) with a mean bias of + 27.5% (SD ± 30.0%). Subgroup analysis of patients < 36 months of age demonstrated that error in mVO was not significantly different from that observed in older patients. Many previously reported prediction models for assuming VO performed poorly in this younger age range. Measured oxygen consumption using the E-sCAiOVX module is significantly more accurate than assumed VO when compared to TD- or cMRI-derived VO in a pediatric catheterization lab.


Anesthesiology and Critical Care Medicine