Impact of the C2/C6 Ratio of High-molecular-weight Hydroxyethyl Starch on Pharmacokinetics and Blood Coagulation in Pigs

Background: High-molecular-weight, low-substituted hydroxyethyl starch (HES) may not affect blood coagulation more than low-molecular-weight, low-substituted HES. The authors assessed in vivo the effect of a lowered C2/C6 ratio on pharmacokinetic characteristics and the impact on blood coagulation of high-molecular-weight, low-substituted HES. Methods: A prospective, randomized, parallel study in 30 pigs compared HES 650/0.42/2.8 with HES 650/0.42/5.6. Before, during, and after infusion of 30 ml/kg body weight HES, blood samples were collected over 630 min to measure HES concentrations and plasmatic coagulation and to assess blood coagulation in whole blood by Thrombelastography ® (TEG ® ; Haemoscope Corporation, Niles, IL). Pharmacokinetic parameters were estimated using a two-compartment model. Results: The elimination constant was 0.009 0.001 min 1 for HES 650/0.42/2.8 and 0.007 0.001 min 1 for HES 650/0.42/