Comparing the Effects of Hydroxy Ethyl Starch 6% and Gelatin as Replacement for Prime during Coronary Artery Bypass Graft Surgery

Several fluids have been used in priming the cardiopulmonary pump in coronary artery bypass graft surgery (CABG). Hydroxy-ethyl starch 6% (HES 6%) is a new colloid fluid which is widely used as a substitute for intraoperative fluid. Gelatin is also a commonly used colloid fluid for priming. However, it has some adverse effects, especially on the coagulation system. In this clinical trial, patients were randomized into two groups of HES 6% and gelatin. Prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR) were measured before surgery and immediately and 24 hours after the operation. Chest drainage (CD) was measured 24 hours after the operation. Urine output (UO) was measured during the first 24 postoperative hours. Blood urea nitrogen (BUN) and creatinine were measured before and 24 hours after surgery. Data was analyzed with SPSS. Totally 100 patients were recruited for this study. CD was not significantly different between HES 6% and gelatin groups. In the HES and gelatin groups the UO was also not significantly different. PT and INR did not show any significant difference betwean the two groups before, at the end and 24 hours after surgery, however PTT was significantly higher(p-value=0.05) in gelatin group only at the end of surgery(30.6± 5.7,44 ± 27,37 ± 19 for HES vs 30.5 ± 5.7,56 ± 35,37 ± 23 for gelatin respectively). BUN was only significantly higher in HES group 24 hours after surgery (19.9 ±9.8 vs 16.4 ± 7.6, Pvalue = 0.05). Cr did not differ. HES and gelatine are both options for prime in cardiopulmonary pomp,with adverse effect on renal function and coagulation respectively.more studies with larger sample sizes are recommended.