title: Measured pulmonary oxygen consumption: difference between systemic oxygen uptake measured by the reverse Fick method and indirect calorimetry in cardiac surgery.
abstract: Measurement of oxygen uptake by indirect calorimetry was compared with the reverse Fick method in a series of patients undergoing cardiac surgery. Oxygen uptake measurements for indirect calorimetry were made using a calibrated measurement system utilizing the Haldane transformation in a simple semiclosed breathing system based upon a modified Bain circuit. Pulmonary blood flow for the reverse Fick method was measured using bolus thermodilution. The results were (mean [standard deviation]): indirect calorimetry 167[26] ml.min(-1), and reverse Fick 148[27] ml.min(-1). Indirect calorimetry overestimated the reverse Fick value by 11.3% (p < 0.001). These results are consistent with the findings of previous studies in similar patient groups and are explained by lung tissue oxygen consumption.
authors.affiliation: Department of Anaesthesia, Austin Hospital, Melbourne, Australia. phil.PEYTON@austin.org.au
authors.forename: P J
authors.initials: PJ
authors.lastname: Peyton
authors.forename: G J B
authors.initials: GJ
authors.lastname: Robinson
mesh_terms: D000368:Aged; D002153:Calorimetry, Indirect; D002302:Cardiac Output; D001026:Coronary Artery Bypass; D006801:Humans; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D011652:Pulmonary Circulation; D011659:Pulmonary Gas Exchange; D015203:Reproducibility of Results; D013815:Thermodilution / Q000379:methods
chemical_list: D010100:Oxygen