Estimating cardiac output from arterial blood pressurewaveforms: a critical evaluation using the MIMIC II database

Abstract

Cardiac output (CO) estimation using arterial blood pressure (ABP) waveforms has been an active area of physiology research over the past century. However, the effectiveness of the estimators has not been extensively studied in a clinical setting. In this paper, we evaluate 11 well-known CO estimators using clinical radial ABP waveforms from the multi-parameter intelligent monitoring for intensive care II (MIMIC II) database, using thermodilution CO (TCO) as reference for comparison. We compare estimations to 988 TCO measurements in 84 patients, totaling 165 hours of ABP waveforms sampled at 125 Hz. As a necessary step for producing absolute CO estimates, we also present 3 methods of calibrating the estimators, each tailored towards a different use model. The results show that the standard deviation of error between TCO and the best CO estimators is approximately 1 L/min for absolute CO estimates. For relative estimates without calibration, the best CO estimator has 18% error at 1 standard deviation