Hotline

Perioperative temperature homeostasis was standardized for all participants. One hour prior to surgery, participants were pre-warmed with a full body warming blanket (Bair Hugger 3 M™, Model 315) set at 43 °C. On arrival to the operating room, the ambient operating room temperature was set at 21 °C, and participants were placed on sterile full access underbody warming blanket (Bair Hugger 3 M™, Model 637) set at 43 °C, placed over a standard operating table. These warming blanket devices were continued during induction of anaesthesia and during insertion of all invasive monitoring lines, after which the full body warming blanket was replaced with an intraoperative upper body warming device that covered both upper limbs and face (Bair Hugger 3 M™, Model 523XL) for the remainder of the case. During the anhepatic phase, ambient operating temperature was increased to 23 °C, with no further adjustments for the remainder of the case. Intraoperatively, crystalloid and colloid fluid intervention, including the use of packed red blood cells were delivered via a Belmont® Rapid Infuser RI-2 system that delivered preheated fluids at 42 °C. If clinically indicated, fresh frozen plasma, platelet and cryoprecipitate transfusions were delivered via a separate HOTLINE® (Smiths Medical, Kent, UK) intravenous warming fluid device, set at 42 °C.

Body temperature was measured in the ward 1 hour before surgery as a baseline temperature to exclude the presence of preoperative hypo- or hyperthermia. Patients did not receive prewarming. A forced-air warming device with an underbody disposable blanket (3M Bair Hugger Model 635) was used to prevent hypothermia. Body warming by the forced-air warmer was started at the time of the surgical incision; the set temperature was 38°C. The environmental temperature in the operating room was set at 25°C with 40% relative humidity until the end of surgery. Intravenous fluids were warmed to 42°C via a fluid warmer (HOTLINE, Smiths Medical, Rockland, MA). Temperature data were recorded every minute, and downloaded as a digital file.