Global end-diastolic volume as an indicator of cardiac preload in hemorrhagic shock and resuscitation in swine

Introduction

Optimal monitoring of cardiac preload is essential during resuscitation from hemorrhagic shock (HSR) to avoid under-resuscitation and over-resuscitation. The maintenance of adequate preload by administration of intravenous fluids remains a primary target to optimize hemodynamics in the early phase of HSR prior to the arrival of blood products. The central venous pressure (CVP) is commonly used as a goal to resuscitation; however, several studies have shown that cardiac filling pressures are not always accurate indicators of ventricular preload. The global end-diastolic volume (GEDV) determined at the bedside by the transpulmonary thermodilution method has been found to better assess cardiac preload in septic patients than CVP but this has not been examined in HSR. The present study was designed to assess the value of GEDV measured by transpulmonary thermodilution as an indicator of cardiac preload in HSR.

Methods

Twenty anesthetized swine underwent a grade V liver injury and bled without resuscitation for 30 minutes. Animals were then resuscitated with study fluid to, and maintained at, the preinjury mean arterial pressure. Hemodynamic parameters were evaluated in triplicate by the transpulmonary thermodilution technique: before and immediately after the liver injury and spontaneous hemorrhage; and 30 minutes after hemorrhage, immediately before and after resuscitation to the preinjury mean arterial pressure.

Results

Changes in the GEDV index were more highly correlated with changes in stroke volume (SV) as compared with changes in CVP versus changes in SV (Figure 1).

Figure 1

Abstract

Conclusion

In this porcine model of traumatic hemorrhagic shock and resuscitation, the GEDV in contrast to the CVP behaved as an indicator of cardiac preload.