INFERIOR VENA-CAVA PRESSURE AS AN ESTIMATE OF CENTRAL VENOUS-PRESSURE

Objective: To determine whether pressure in the inferior vena cava (IV C) is similar to central venous pressure. Methodology: Prospective mea surement of both central venous pressure (CVP) and inferior vena cava pressure (IVCP) in the same child; each child had to have both cathete rs in situ. Two measurements of each pressure in reverse order (IVCP t hen CVP, and CVP then IVCP) were done and the mean of each was recorde d. Comparison of the pressures was performed using the method of Bland and Altman.Results: Thirty-nine children had pressures recorded. The CVP ranged from 3 to 17 mmHg. In 22 of 39 measurements IVCP was equal to CVP; in 33 of 39 measurements IVCP was different from CVP by 1 mm o r less and in 37 of 39 measurements IVCP was different from CVP by 2 m m or less. The mean difference between IVCP and CVP was + 0.33 mmHg, t he 95% confidence interval was 2.26 to + 2.93 mmHg. Conclusion: Measur ement of IVCP is a good approximation to CVP and can be routinely used in clinical care of children who do not have raised intra-abdominal p ressure.