Bias, trending ability and diagnostic performance of a non-calibrated multi-beat analysis continuous cardiac output monitor to identify fluid responsiveness in critically ill patients.

ABSTRACT

Objective: To evaluate the accuracy of non-calibrated multi-beat analysis continuous cardiac output (CCOMBA), against calibrated pulse-contour analysis continuous cardiac output (CCOPCA) during a passive leg raise (PLR) and/or a fluid challenge (FC). Design: Observational, single-centre, prospective study. Setting: Tertiary academic medical intensive care unit, Lyon, France. Participants: Adult patients receiving norepinephrine, monitored by CCOPCA, and in which a PLR and/or a FC was indicated. Main outcome measures: CCOMBA and CCOPCA were recorded prior to and during the PLR/FC to evaluate bias and evaluate changes in CCOMBA and CCOPCA (∆%CCOMBA and ∆%CCOPCA). Fluid responsiveness was identified by an increase >15% in calibrated cardiac output after FC, to identify the optimal ∆%CCOMBA threshold during PLR to predict fluid responsiveness. Results: 29 patients (median age 68 [IQR 57-74]) performed 28 PLR and 16 FC. The bias between methods increased with higher CCOPCA values, with a percentage error of 64% (95%confidence interval 52%-77%). ∆%CCOMBA adequately tracked changes in ∆%CCOPCA with an angular bias of 2 ± 29°. ∆%CCOMBA during PLR had an AUROC of 0.92 (P < 0.05), with an optimal threshold >14% to predict fluid responsiveness (sensitivity 0.99, specificity 0.87). Conclusions: CCOMBA showed a non-constant bias and a percentage error >30% against calibrated CCOPCA, but an adequate ability to track changes in CCOPCA and to predict fluid responsiveness.