Cardiopulmonary bypass(CPB) is associated with increased fluid extravasation and edema formation. A continuous infusion of a mixture of hypertonic saline/hydroxyethyl starch (HSH)during CPB reduced fluid extravasation and total fluid gain during bypass in an animal model. We hypothesize that a continuous infusion of HSH will reduce fluid load and increase hemodynamic and respiratory functions in patients undergoing coronary artery bypass with CPB.

Cardiopulmonary bypass (CPB) is associated with fluid overload and edema formation occasionally resulting in vital organ dysfunction affecting heart, respiratory system , gastrointestinal tract and brain. Hyperosmolar/hyperoncotic preparations (HSH/HSD) have been used in cardiac surgery essentially with the aim to mobilize fluid excess and improve postoperative cardiorespiratory function.Most studies dealing with the administration of HSD or HSH during and after CPB, have used protocols recommended for treatment of severe hypovolemia and shock, that is 4 mL/kg as a bolus, given within minutes.In animal experiments we have used HSD or HSH, 1 mL/kg/h to a total dose of 4 mL/kg during CPB. The use of HSH/HSD reduced the total fluid gain about 50 % and resulted in significantly lower content of tissue water in vital organs as heart and lungs. In the actual clinical trial we hypothesize that a continuous infusion of HSH will reduce fluid load and increase hemodynamic and respiratory functions monitored with the PiCCO system in patients undergoing coronary artery bypass with CPB.

Inclusion Criteria:

• Patients scheduled for elective coronary artery bypass graft surgery

Exclusion Criteria:

• Age <18 years or > 75 years
• BMI< 18 or > 30
• Left ventricular ejection fraction < 40%
• Emergency operations
• Additional valvular diseases
• Impaired renal function
• Serum sodium> 145 mmol/l
• Hematocrit< 30%
• Use of clopidogrel the last 5 days