文摘
Our objective was to compare calculated (LaFarge) with measured oxygen consumption (VO2) using the AS/3 TM Compact Airway Module M-CAiOVX (Datex-Ohmeda, Helsinki, Finland; AS/3 TM) in children without cardiac shunts in a prospective, observational study. VO2 was determined at the end of the routine diagnostic and/or interventional catheterization. VO2 was calculated according to the formula of LaFarge and Miettinen for each child and compared with the measured VO2. Data were compared using simple regression and Bland Altman analysis. Fifty-two children aged from 0.5 to 16 years (median, 6.9 years) and weighing 3.4 to 59.4 kg (median, 22.9 kg) were investigated. Calculated VO2 values ranged from 59.0 to 230.8 ml/min, and measured VO2 values from 62.7 to 282.2 ml/min. Comparison of calculated versus measured VO2 values revealed a significant correlation (r = 0.90, p < 0.0001). Bias and precision were 8.9 and 48.3 ml/min, respectively (95 % limits of agreement: −39.4 to 57.2 ml/min). Comparison of calculated VO2 in children older than 3 years (n = 41), as restricted to the formula, with measured VO2, revealed a slightly reduced correlation (r = 0.86, p < 0.0001). Bias and precision were 10.0 and 52.5 ml/min, respectively (95 % limits of agreement: –42.4 to 62.5 ml/min). We conclude that calculation of VO2 by the LaFarge formula does not provide reliable values compared to measured values. In clinical routine, measured rather than calculated VO2 values should be used for the estimation of cardiac output and related variables.