The effect of fluid resuscitation on the effective circulating volume in patients undergoing liver surgery: a post-hoc analysis of a randomized controlled trial

Jaap Jan Vos,A F Kalmar,J Bakker,T W L Scheeren,H G D Hendriks

doi:10.1007/s10877-017-9990-5

Abstract

To assess the significance of an analogue of the mean systemic filling pressure (Pmsa) and its derived variables, in providing a physiology based discrimination between responders and non-responders to fluid resuscitation during liver surgery. A post-hoc analysis of data from 30 patients undergoing major hepatic surgery was performed. Patients received 15 ml kg−1 fluid in 30 min. Fluid responsiveness (FR) was defined as an increase of 20% or greater in cardiac index, measured by FloTrac-Vigileo®. Dynamic preload variables (pulse pressure variation and stroke volume variation: PPV, SVV) were recorded additionally. Pvr, the driving pressure for venous return (=Pmsa–central venous pressure) and heart performance (EH; Pvr/Pmsa) were calculated according to standard formula. Pmsa increased following fluid administration in responders (n = 18; from 13 ± 3 to 17 ± 4 mmHg, p < 0.01) and in non-responders (n = 12; from 14 ± 4 to 17 ± 4 mmHg, p < 0.01). Pvr, which was lower in responders before fluid administration (6 ± 1 vs. 7 ± 1 mmHg; p = 0.02), increased after fluid administration only in responders (from 6 ± 1 to 8 ± 1 mmHg; p < 0.01). EH only decreased in non-responders (from 0.56 ± 0.17 to 0.45 ± 0.12; p < 0.05). The area under the receiver operating characteristics curve of Pvr, PPV and SVV for predicting FR was 0.75, 0.73 and 0.72, respectively. Changes in Pmsa, Pvr and EH reflect changes in effective circulating volume and heart performance following fluid resuscitation, providing a physiologic discrimination between responders and non-responders. Also, Pvr predicts FR equivalently compared to PPV and SVV, and might therefore aid in predicting FR in case dynamic preload variables cannot be used.

Highlights

The basis of hemodynamic management in critically ill patients and in patients undergoing major surgery is formed by a rational titration of fluids, vasopressors and inotropes, with the ultimate goal to maintain sufficient tissue oxygen delivery [1]
A hallmark feature of most of the goal-directed fluid therapy (GDFT) approaches is the assessment of fluid responsiveness (FR), i.e. to assess whether cardiac output (CO) will increase following a fluid bolus
18/30 patients demonstrated an increase in CI > 20% and were regarded as fluid responders; 12/30 patients were regarded as non-responders

Summary

Introduction

The basis of hemodynamic management in critically ill patients and in patients undergoing major surgery is formed by a rational titration of fluids, vasopressors and inotropes, with the ultimate goal to maintain sufficient tissue oxygen delivery [1]. Studies suggest that a so-called (early) goal-directed fluid therapy (GDFT) might reduce post-operative complications [2, 3]. A hallmark feature of most of the GDFT approaches is the assessment of fluid responsiveness (FR), i.e. to assess whether cardiac output (CO) will increase following a fluid bolus. Dynamic preload variables, such as pulse pressure variation and stroke volume variation (PPV and SVV, respectively), are currently the clinical gold standard for the prediction of FR [4,5,6]. Dynamic preload variables only provide a partial, simplified picture

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