Cardiopulmonary Bypass Prime Solution in Patients Undergoing Heart Valve Surgery

In this randomized clinical trial, patients with undergoing open heart valve surgery will be enrolled into the study. Participants will be divided into two groups based on the priming solution type. The first group will receive hydroxyethyl starch (HES) 130/0.4 additive to ringer lactate (RL) and the second group will be given only RL as priming solution. All patients will be observed closely during postoperative days. Through follow up, bleeding/coagulopathy, renal function, hepatic function, and cerebral oxygenation will be recorded in both groups.

Cardiopulmonary bypass (CPB) pump is a device for circulating blood in the body while the heart is undergone surgery. For providing circulating volume in the body we need to add about 1.5 to 2 lit fluids as priming solution in the CPB pump. Some fluids mainly included crystalloids, colloids, starch, and gelatin in an only fluid or in a combined formula. During CPB time, the blood dilution is caused by adding prime solution into the circulating volume, and consequently it decreases blood viscosity. Moreover, in addition to a decrease in hematocrit level, coagulation factors and plasma proteins can dramatically decreased. These processes may lead to bleeding events and tissue hypoperfusion and organ damages. To decrease complications, some modalities such as adding colloids to crystalloids have been implemented. On the other hand, any regimen for priming solution has its shortcomings need to be considered based on patient condition and surgical issue. In this double blinded randomized clinical trial study, we aimed to compare the the effects of six percent HES 130/0.4 and RL as priming solutions on coagulation factors, renal function, hepatic function, and cerebral oxygenation in patients undergoing open heart valve surgery.

Inclusion Criteria: patients who provided written informed consent and had no heart failure (LVEF >55%), no hepatic failure (defined as aspartate aminotransferase (AST) >40 mg/dL and/or alanine aminotransferase (ALT) >40 mg/dL), no prior history of cardiac surgery, serum creatinine <1.5 mg/dL, no episode of drug-induced acute kidney injury within preoperative 5 days, no severe carotid stenosis in both or one of them, no emergency valvular stenosis, no infective endocarditis, no severe right ventricular failure, no hemoglobin <10 mg/dL, no body mass index >40 kg/m2, no heparin-induced thrombocytopenia, no cancer, no severe pulmonary valve insufficiency, no pulmonary function test <65% before heart valve surgery Exclusion Criteria: included consent withdrawal by the patient or by his/her proxy, allergic reaction to the drugs, the aortic cross clamp time greater than 120 minutes, on-pump time greater than 150 minutes, the performance of the retrograde autologous priming.