A prospective randomized comparison of a pulse-contour analysis monitor versus a non-invasive bioreactance monitor in a stroke-volume based goal-directed fluid resuscitation protocol in brain-dead organ donors

Abstract

Background

Brain-dead (BD) organ donors are frequently hypotensive and hypovolemic requiring fluid resuscitation. We previously published our four-hour stoke volume (SV)-based fluid resuscitation protocol that expeditiously corrected the fluid deficit and significantly decreased time on vasopressors. The SV was measured by pulse-contour analysis (PCA).

Objective

To determine if the measurement of stroke volume by bioreactance (BR) was equivalent to PCA in a goal-directed fluid resuscitation protocol in BD donors.

Methods

We performed a prospective randomized trial of fluid resuscitation in BD donors comparing the two monitors.

Results

In 169 deceased donors there were 1481 comparative measurements of SV. The correlation coefficient was 0.32. A Bland Altman analysis revealed a minimal bias (-1.8 ml) but large limits of agreement (±62.9 ml) and a percentage error of 80.5 %. A 10 % SV increase with a 500 ml fluid bolus had conflicting results between the monitors in 31.3 % of 1309 measurements. As a reference standard, the Fick method of measuring SV was used 49 times with simultaneous measurements of PCA-SV and BR-SV. The mean Fick SV (96.0 ± 30.6 ml) was significantly greater than BR (79.4 ± 18.1 ml; p<.01) and the PCA (77.2 ± 22.5 ml; p<.01). The mean SV differences for Fick-BR (16.6 ± 27.2, 95 % CI 8.78–24.42) and Fick-PCA (18.7 ± 29.0, 95 % CI 10.42–27.08) were not significantly different (p=.57).

Conclusion

Although this study demonstrated inaccuracies, imprecision, and disagreement between BR and PCA SV measurements, there was equipoise in clinical outcomes when used with our fluid resuscitation protocol, as previously published.