Effects of mild hypothermia on blood coagulation in patients undergoing elective plastic surgery.

Background: The aim of this prospective, controlled study was to evaluate the effects on coagulation function of active patient warming during elective plastic surgery. Methods: Seventy-sik patients undergoing elective plastic surgery (additive and reductive mastoplasty, rhinoplasty, and liposuction) were either covered with standard sterile drapes (control group, n = 38) or actively warmed during surgery with countercurrent fluid warming and forced-air skin warming (treatment group, n = 38). Complete evaluation of the coagulation activity was performed 1 hour before general anesthesia was induced and then at the end of surgery. Results: Although no differences in preoperative core temperature were observed (36.0 ± 0.5°C in the control group and 36.1 ± 0.4°C in the treatment group; p = 0.12), core temperature was lower at the end of surgery in the control group (34 ± 1.0°C) than in the treatment group (36 ± 0.6°C) (p = 0.0005). No differences in prothrombin time and fibrinogen plasma concentrations were observed between the two groups. At the end of surgery, control group patients showed significantly larger activated partial thromboplastin times (36.8 ± 3.5 seconds) and bleeding times (8.1 ± 1.6 minutes) as compared with patients maintained normothermic during surgery (34.0 ± 2.9 seconds and 4.3 ± 1.1 minutes; p = 0.0005 and p = 0.0005, respectively). Conclusion: Actively maintaining intraoperative normothermia allows patients to maintain normal coagulation function during elective plastic surgery lasting longer than 2 hours, potentially reducing the occurrence of bleeding-related complications after plastic surgery.