A prospective, randomized comparison of thromboelastographic coagulation profile in patients receiving lactated Ringer's solution, 6% hetastarch in a balanced-saline vehicle, or 6% hetastarch in saline during major surgery

Objectives: To compare the effects of lactated Ringer's solution (LR), 6% hetastarch in a balanced-saline vehicle (HS-BS), and 6% hetastarch in normal saline (HS-NS) on coagulation using thromboelastography. Design: Prospective, randomized double-blinded evaluation of previously published clinical trial. Setting: Tertiary-care medical center. Participants: Patients undergoing elective noncardiac surgery with an anticipated blood loss >500 mL. A total of 90 patients were enrolled with 30 patients in each group. Interventions: Patients received a standardized anesthetic. LR, HS-BS, and HS-NS were administered intraoperatively based on a fluid administration algorithm. Hemodynamic targets included maintenance of arterial blood pressure, heart rate, and urine output within a predefined range. Measurements and Main Results: Thromboelastography variables for r time, k time, maximum amplitude, and α angle (mean ± SD) were recorded at induction of anesthesia, at the end of surgery, and 24 hours postoperatively. Patients in the LR group showed a state of hypercoagulation at the end of surgery with reductions (p < 0.005) in r time (−3.8 ± 6.7 mm) and k time (−1.7 ± 2.5 mm). This state of hypercoagulation continued into the postoperative period. Patients in the HS-NS group showed a state of hypocoagulation with increases (p < 0.05) in r time (+6.2 ± 8.5 mm) and k time (+1.7 ± 3.9 mm) and a reduction in maximum amplitude (−8.0 ± 9.8 mm) at the end of surgery. This state of hypocoagulation was reduced in the postoperative period. Patients in the HS-BS group showed no significant changes in coagulation status at end of surgery, with the smallest changes in r time (−0.3 ± 4.1 mm), k time (+0.1 ± 3.1 mm), maximum amplitude (−5.4 ± 12.3 mm), and α angle (0.3 ± 12.5°). Conclusion: LR-treated patients exhibited a hypercoagulative profile that persisted into the postoperative period. HS-BS administration was associated with a lesser change in the coagulation profile compared with HS-NS, which was associated with a hypocoagulative state. Copyright 2002, Elsevier Science (USA). All rights reserved.