Effects of acute hypervolemic hemodilution on hemodynamics, blood coagulation and renal function in patients undergoing vertebral surgery

AIM: To evaluate the effects of acute hypervolemic hemodilution (AHH) on hemodynamics, blood coagulation and renal function. METHODS: Eighteen patients undergoing vertebral surgical procedures were randomly divided into control (C) group and AHH group after induction of anesthesia. AHH was produced by preoperative infusion of 15-20 mL·kg -1 of 60 g·L -1 hydroxyethyl starch (HES) at the rate of 30 mL·min -1 without removing blood. Mean arterial blood pressure (MAP), heart rate (HR) and central venous pressure (CVP) were monitored for 24 hours. Blood analysis, blood coagulation, renal function and arterial blood gas analysis were made before and after AHH, at the end of surgery and 24 h after operation. Arterial oxygen content (CaO 2) was calculated and intraoperative blood loss, transfusion requirements and postoperative transfusion requirements were recorded. RESULTS: Blood loss and transfusion requirements were similar in the two groups. Allogeneic blood volume in AHH group was less than that in control group ( P 0.05). Variable of hemodynamics in AHH group was more stable than that in control group. MAP and CVP after AHH in AHH group were higher than those in control group ( P 0.05). Red blood cell (RBC) volumes, hemoglobin concentration (Hb) and hematocrit (Hct) significantly decreased from post operation to 1 day post operation in AHH group ( P 0.05, P 0.01 ). Remarkable difference of RBC, Hb and Hct was found in AHH group post operation compared with those in control group ( P 0.05). There was no significant change in the blood coagulation and renal function throughout the study. CONCLUSION: AHH with 60 g·L -1 HES is safe and effective to reduce homologous blood transfusion and increase the tolerance for blood loss during vertebral surgery .