Endothelial Function After Cardiac Surgery

The purpose of this study is to evaluate whether patients receiving human albumin for plasma volume replacement during cardiac surgery have improved postoperative endothelial function compared to patients receiving 6% hydroxyethyl starch solutions. The postoperative endothelial function, measured with peripheral arterial tonometry as reactive hyperemia index (RHI) within 2 hours following surgery, will be compared in cardiac surgical patients randomized to receive human albumin or 6% HES solutions for intraoperative volume replacement. Within two hours of arrival to the ICU peripheral arterial tonometry using EndoPAT will be performed. In a subset of 40 consecutive patients the investigators will perform additional EndoPAT measurements to describe the expected changes that occur in endothelial function during the perioperative period (baseline, early postoperative and 24 hours postoperative) using RHI. This study will also determine whether human albumin 5% reduces plasma biomarkers of endothelial and glycocalyceal damage by measuring plasma concentrations of syndecan 1 and endocan at baseline (before surgery), and 1 and 24 hours following surgery. Blood samples will be taken on the morning of the surgery, within one hour of arrival to the intensive care unit (ICU), and 24 hours after surgery or within 2 hours before discharge from the ICU (three times altogether). These samples will be used to measure the plasma concentrations of two biomarkers that measure endothelial injury.