title: Comparison of indirect calorimetry and thermodilution cardiac output measurement in children.
abstract: We validated experimentally the ability of hood indirect calorimetry to measure accurately VO2. For this purpose we compared cardiac output calculated from the Fick equation Q = VO2/(Ca(O2) - CV(O2)), in which VO2 was obtained by hood indirect calorimetry, to thermodilution cardiac output (Qth) measured simultaneously during cardiac catheterization in children (n = 16). Because FI(CO2) is a critical factor in hood indirect calorimetry calculations, we also assessed the consequence of taking into account measured FI(CO2) rather than using the usual standard value of 0.0004. We found a good agreement between Q and Qth whether we used experimentally measured FI(CO2) in ambient air (Qth = 0.89 Q + 0.39, r = 0.941) or standard FI(CO2) (Qth = 0.84 Q + 0.55, r = 0.930). However, VCO2 and R computed from standard FI(CO2) differed significantly (p < 0.001) from values derived from measured FI(CO2). This demonstrates that indirect calorimetry allows reasonable estimates of Q, VO2, VCO2, and R provided that the actual values of FI(CO2) are used.
authors.affiliation: Hôpital Marie-Lannelongue and Département de Physiologie, Faculté deMedécine Pitié-Salpêtrière, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Capderou
authors.forename: D
authors.initials: D
authors.lastname: Douguet
authors.forename: J
authors.initials: J
authors.lastname: Losay
authors.forename: M
authors.initials: M
authors.lastname: Zelter
mesh_terms: D000293:Adolescent; D002153:Calorimetry, Indirect; D002302:Cardiac Output; D002648:Child; D002675:Child, Preschool; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008955:Models, Cardiovascular; D010101:Oxygen Consumption; D013815:Thermodilution / Q000379:methods