The response of a standardized fluid challenge during cardiac surgery on cerebral oxygen saturation measured with near-infrared spectroscopy

Frederik Holmgaard,Thomas W L Scheeren,Hanne B Ravn,Simon T Vistisen

doi:10.1007/s10877-019-00324-w

Abstract

Near infrared spectroscopy (NIRS) has been used to evaluate regional cerebral tissue oxygen saturation (ScO2) during the last decades. Perioperative management algorithms advocate to maintain ScO2, by maintaining or increasing cardiac output (CO), e.g. with fluid infusion. We hypothesized that ScO2 would increase in responders to a standardized fluid challenge (FC) and that the relative changes in CO and ScO2 would correlate. This study is a retrospective substudy of the FLuid Responsiveness Prediction Using Extra Systoles (FLEX) trial. In the FLEX trial, patients were administered two standardized FCs (5 mL/kg ideal body weight each) during cardiac surgery. NIRS monitoring was used during the intraoperative period and CO was monitored continuously. Patients were considered responders if stroke volume increased more than 10% following FC. Datasets from 29 non-responders and 27 responders to FC were available for analysis. Relative changes of ScO2 did not change significantly in non-responders (mean difference − 0.3% ± 2.3%, p = 0.534) or in fluid responders (mean difference 1.6% ± 4.6%, p = 0.088). Relative changes in CO and ScO2 correlated significantly, p = 0.027. Increasing CO by fluid did not change cerebral oxygenation. Despite this, relative changes in CO correlated to relative changes in ScO2. However, the clinical impact of the present observations is unclear, and the results must be interpreted with caution.Trial registration:http://ClinicalTrial.gov identifier for main study (FLuid Responsiveness Prediction Using Extra Systoles—FLEX): NCT03002129.

Highlights

In the last decades, near infrared spectroscopy (NIRS) monitoring has gained interest as a tool to monitor cerebral oxygenation and perfusion during cardiac surgery in an attempt to minimize cerebral complications [1,2,3,4]
We studied the association between relative changes in ScO2 and cardiac output (CO) during a standardized fluid challenge (FC) in hemodynamic responders and nonresponders to a FC in adult patients undergoing cardiac surgery
The main finding of the present study was that the S cO2 did not change for both responders and non-responders of a FC during cardiac surgery

Summary

Introduction

Near infrared spectroscopy (NIRS) monitoring has gained interest as a tool to monitor cerebral oxygenation and perfusion during cardiac surgery in an attempt to minimize cerebral complications [1,2,3,4]. Numerous intervention algorithms to mitigate and reverse cerebral desaturation have been published, of which the one published in 2007 appears widely adopted [7]. Application of this hierarchical algorithm has lowered the time with cerebral desaturation measured by NIRS [8,9,10,11]. Part of the intervention algorithm is to increase cardiac output (CO) if cerebral desaturation occurs as indicated by decreased S cO2.

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Results

Conclusion