Background and Goal of study: Patients become hypothermic during off pump cardiopulmonary bypass surgery (OPCAB) and are exposed to its deleterious effects (1). We evaluated the efficacy in avoiding intraoperative hypothermia of Allon Thermo WrapTM system: water at a preset desired temperature (T) to a specially designed garment, vs. sterile forced air warming blankets (2).
Materials and Methods: We randomized 32 patients scheduled for elective OPCAB surgery, 3 were excluded after reconverted to CAB [(Group-A)14 pts warmed by Allon, core T objective 36.5°C; (Group-B)15 pts warmed by sterile Bear HuggerTM, this blanket was placed on the lower extremities after the saphenous section had been sutured]. We collected core T by a nasopharyngeal catheter every 30 min from intubation to the end of surgery. All patients received warmed fluids. The operating room T range was 20-22°C. The Brat 2TM autologous blood recovery system was set up in all cases.
Results and Discussion: There were no statistically significant differences between group's variables: Age, body surface, ejection fraction, infusions, Hb, and Brat volume recovery. Core T values (Mean ± SD) are shown in the Table.
Patients of Group-A maintained normothermia because they could be warmed actively before of anesthesia induction and during all procedure. Most of the pts of Group-B were hypothermic at the moment that air blankets, were started, needing active warming after ICU admission.
Conclusion: Normothermia can be achieved efficiently during OPCAB procedures using the Allon system. It was found to be superior to the air blankets method.
1 Stanley T. Ann Thorac Surg 2003;75:1140-4.
2 Nesher N. Anesth Analg 2003;96:328-35.