Hemodilution with Hydroxyethyl Starch During Cardiopulmonary Bypass: Review of a Multi-Institutional Study

Three colloidal plasma expanders for use during cardiopulmonary bypass were compared in 85 patients treated at four Japanese hospitals. Patients were randomly allocated to receive: Hydroxyethyl Starch (HES) 5 ml/kg, HES 10 ml/kg, gelatin (Haemacel 10 ml/kg), or a mixture of HES 5 ml/kg and low viscosity dextran (LVD) 5 ml/kg, in addition to the usual priming dose of 1000-1500 ml Lactated Ringer's solution, 20 gm/dl mannitol, and heparinized whole blood. These colloidal plasma expanders appeared equivalent in safely replacing whole blood. Following surgery, urine outputs increased slightly, there were transient elevations of SGOT, LDH, and serum bilirubin, and transient decrements in serum alkaline phosphatase, Na, K, and Cl concentrations. Serum protein, one week following surgery was decreased, possibly reflecting persistence of the plasma expanders. There was no increased bleeding or prolongation of clotting times, bleeding times, or prothrombin times, even though platelet counts were low following surgery. Plasma hemoglobin concentrations were greater in patients receiving gelatin as compared with those given HES. Hydroxyethyl Starch (6 gm/dl), a new plasma expander, appears to be efficacious and nontoxic in hemodilution extracorporeal perfusion. The priming solution employed in the extracorporeal circuit has undergone refinement to limit denaturation of blood and consequent clinical sequelae.5,29,30,40 Initially, heparinized whole blood primed the circuit, but the possibility of incompatible blood administration, transmission of viral hepatitis, and nonhemolytic reactions of a febrile or allergic nature became apparent with the use of homologous blood.10,23 Development and improvement of colloidal and crystalloid solutions for hemodilution, has conserved blood and prevented adverse effects attendant upon blood transfusion.12,19,21,24 The use of hemodilution has allowed prolongation of the perfusion period, expanding the application of open heart surgery.21 The present study compares the efficacy and toxicity of hydroxyethyl starch (HES) and gelatin in 85 patients during open heart surgery