Ringer's Acetat Versus Balanced Hydroxyethyl-starch as Primesolution in the Heart-lung Maschine During Cardio-pulmonary-bypass. Postoperatively Fluid Balance and Cardiac Function

"The impact on fluid loading after cardiac surgery by use of two different priming solution"

Fluid overloading with oedema formation is a regular finding following on-pump cardiac surgery and may contribute to postoperative organ dysfunction. Myocardial oedema has been reported to impair both systolic and diastolic function. An association between intraoperative fluid loading and postoperative adverse outcome has been demonstrated in cardiac patients.

The investigators have experience with the use of both colloides and combination fluids (hypertonic saline/colloides) in several experimental studies (pigs). In one animal study the investigators used colloides as an additive to the CPB-prime. The investigators observed reduced fluid leakage and less total tissue water in several organs.

The planned study includes patients scheduled for coronary artery bypass, and who have no co-morbidity. The patients will be randomized to receive either Tetraspan® (HES) or acetated Ringer's solution in the CPB-prime. Accurate accounts of fluid additions, blood loss and diuresis will be kept. Determination of cardiac output (C.O.), intrathoracic blood volume (ITBV), extravascular lung water (EVLW) and global end diastolic volume (GEDV) will be monitored by use of the transpulmonary thermodilution technique PiCCO®plus system.