Research

Perioperative indocyanine green clearance is predictive for prolonged intensive care unit stay after coronary artery bypass grafting - an observational study

Michael Sander¹ , Claudia D Spies¹ , Katharina Berger¹ , Torsten Schröder¹ , Herko Grubitzsch² , Klaus D Wernecke³ and Christian von Heymann¹

¹  Department of Anaesthesiology and Intensive Care Medicine, Charité Universitätsmedizin - Berlin, Campus Virchow Klinikum and Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany

²  Department of Cardiovascular Surgery, Charité Universitätsmedizin - Berlin, Campus Charité Mitte, Charitéplatz 1, 10117 Berlin, Germany

³  SOSTANA GmbH, Wildensteiner Str. 27, 10318 Berlin, Germany

author email corresponding author email

Critical Care 2009, 13:R149doi:10.1186/cc8045

Published:	14 September 2009

Abstract

Introduction

During cardiac surgery with cardiopulmonary bypass (CPB) haemodilution occurs. Hepatic dysfunction after CPB is a rare, but serious, complication. Clinical data have validated the plasma-disappearance rate of indocyanine green (PDR ICG) as a marker of hepatic function and perfusion. Primary objective of this analysis was to investigate the impact of haemodilutional anaemia on hepatic function and perfusion by the time course of PDR ICG and liver enzymes in elective CABG surgery. Secondary objective was to define predictors of prolonged ICU treatment like decreased PDR ICG after surgery.

Methods

60 Patients were subjected to normothermic CPB with predefined levels of haemodilution anaemia (haemotacrit (Hct) of 25% versus 20% during CPB). Hepatic function and perfusion was assessed by PDR ICG, plasma levels of aspartate aminotransferase (ASAT) and α-GST. Prolonged ICU treatment was defined as treatment ≥ 48 hours.

Results

Logistic regression analysis showed that all postoperative measurements of PDR ICG (P < 0.01), and the late postoperative ASAT (P < 0.01) measurement were independent risk factors for prolonged ICU treatment. The predictive capacity for prolonged ICU treatment was best of the PDR ICG one hour after admission to the ICU. Furthermore, the time course of PDR ICG as well as ASAT and α-GST did not differ between groups of haemodilutional anaemia.

Conclusions

Our study provides evidence that impaired PDR ICG as a marker of hepatic dysfunction and hypoperfusion may be a valid marker of prolonged ICU treatment. Additionally this study provides evidence that haemodilutional anaemia to a Hct of 20% does not impair hepatic function and perfusion.

Trial registration

[ISRCTN35655335]