Inaccuracy of Estimated Resting Oxygen Uptake in the Clinical Setting

Article

关键词: CONGENITAL HEART-DISEASE;    CARDIAC-OUTPUT;    CONSUMPTION;    VALIDITY;    CHILDREN;    FORMULA;   

DOI  :  10.1161/CIRCULATIONAHA.113.003334

来源: SCIE

【 摘 要 】

Background-The Fick principle (cardiac output = oxygen uptake (V. O 2)/systemic arterio-venous oxygen difference) is used to determine cardiac output in numerous clinical situations. However, estimated rather than measured V. O 2 is commonly used because of complexities of the measurement, though the accuracy of estimation remains uncertain in contemporary clinical practice. Methods and Results-From 1996 to 2005, resting V. O 2 was measured via the Douglas bag technique in adult patients undergoing right heart catheterization. Resting V. O 2 was estimated by each of 3 published formulae. Agreement between measured and estimated V. O 2 was assessed overall, and across strata of body mass index, sex, and age. The study included 535 patients, with mean age 55 yrs, mean body mass index 28.4 kg/m2; 53% women; 64% non-white. Mean ( standard deviation) measured V. O 2 was 241 57 ml/min. Measured V. O 2 differed significantly from values derived from all 3 formulae, with median (interquartile range) absolute differences of 28.4 (13.1, 50.2) ml/min, 37.7 (19.4, 63.3) ml/min, and 31.7 (14.4, 54.5) ml/min, for the formulae of Dehmer, LaFarge, and Bergstra, respectively (P< 0.0001 for each). The measured and estimated values differed by > 25% in 17% to 25% of patients depending on the formula used. Median absolute differences were greater in severely obese patients (body mass index > 40 kg/m2), but were not affected by sex or age. Conclusions-Estimates of resting V. O 2 derived from conventional formulae are inaccurate, especially in severely obese individuals. When accurate hemodynamic assessment is important for clinical decision-making, V. O 2 should be directly measured.

【 授权许可】

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