A meta-analysis of the accuracy and precision of the ultrasonic cardiac output monitor (USCOM).

The ultrasonic cardiac output monitor is a non-invasive, continuous-wave Doppler monitor that can be used to measure cardiac output. Its accuracy and precision in peri-operative and critical care has been assessed with varied results. We conducted a meta-analysis to calculate a pooled mean bias, precision and percentage error for this device. Six studies were suitable for inclusion into a pooled parametric analysis consisting of 320 measurements. The mean weighted bias was -0.39 l.min(-1) (95% CI -0.25 to -0.53 l.min(-1) ), precision 1.27 l.min(-1) and percentage error 42.7% (95% CI 38.5-46.9%). The ultrasonic cardiac output monitor achieved similar agreement with bolus thermodilution to that of other minimally invasive methods of peri-operative cardiac output monitoring, and may have a useful role in cardiac output monitoring.