Repeatability of USCOM®-measured cardiac output in normotensive non-pregnant and pregnant women.

Abstract

Objectives To investigate the repeatability of ultrasonic cardiac output monitor (USCOM) measurements of cardiac output in normotensive non-pregnant and pregnant women. Study design Using the USCOM, cardiac output was measured, five times successively within 5 min in normotensive non-pregnant (n = 30) and pregnant (n = 30) women of any gestation with uniform technique by a single operator. The data were analysed using multi-level modeling and intra-class correlation. Results There was no statistically significant variation in cardiac output with repeated measurement in normotensive non-pregnant or pregnant women. The intra-class correlation for cardiac output measurements was 0.921 (95% CI 0.887–0.947). Conclusions No extra information is added by making more than one USCOM measurement on the same woman under the same conditions in normotensive pregnant and non-pregnant women. The USCOM demonstrates excellent repeatability in this population. This finding should provide reassurance that single measurements using this system are of value in research and clinical practice.