Hemostatic and electrolyte effects of hydroxyethyl starches in patients undergoing posterior lumbar interbody fusion using pedicle screws and cages.

Study Design. Prospective, randomized, double blind, clinical study. Objective. To compare the hemostatic and electrolyte effects of 2 commonly administered hydroxyethyl starches (HES) in patients undergoing posterior lumbar interbody fusion (PLIF). Summary of Background Data. HES are commonly administered colloid solutions to restore and maintain intravascular volume before transfusion is initiated. However, infusion of HES itself can impair coagulation. HES-induced coagulopathy could be a serious problem in PLIF which involves continuous bone bleeding and oozing. Voluven (Fresenius Kabi, Germany), previously regarded as the least coagulopathic due to its low molecular weight (MW) and degree of substitution (DS), is a saline-based HES. Hextend (Biotime, United States) is a new type of HES with physiologic pH and balanced electrolytes, including calcium, which is beneficial to coagulation. Studies comparing the coagulopathy of Hextend and Voluven are rare. Therefore, coagulation, pH/electrolyte changes, and blood loss using Hextend and Voluven in patients undergoing PLIF were compared. Methods. Fifty-four patients scheduled for PLIF involving 3 vertebrae or less were randomly assigned to the Voluven or the Hextend group. Of each solution 15 mL/kg was administered during surgery. Blood loss, coagulation, and electrolyte profiles were checked before infusion and 5 minutes, 3 hours, and 24 hours after the end of infusion. Results. The Hextend group showed slightly better electrolyte balance, however, more coagulation impairment and postoperative transfusion (37% vs. 11%) compared with the Voluven group. The effect of Hextend on coagulation lasted until 24 hours after infusion. Conclusion. If coagulopathy is a concern during PLIF, then, a HES with low MW/DS in a saline-based medium (Voluven) may be a better alternative than a HES with high MW/DS in a balanced salt medium (Hextend).