title: Prevention of hypothermia in patients undergoing orthotopic liver transplantation using the humigard® open surgery humidification system: a prospective randomized pilot and feasibility clinical trial.
abstract: BACKGROUND
  Perioperative thermal disturbances during orthotopic liver transplantation (OLT) are common. We hypothesized that in patients undergoing OLT the use of a humidified high flow CO2warming system maintains higher intraoperative temperatures when compared to standardized multimodal strategies to maintain thermoregulatory homeostasis.
  
  
  METHODS
  We performed a randomized pilot study in adult patients undergoing primary OLT. Participants were randomized to receive either open wound humidification with a high flow CO2warming system in addition to standard care (Humidification group) or to standard care alone (Control group). The primary end point was nasopharyngeal core temperature measured 5 min immediately prior to reperfusion of the donor liver (Stage 3 - 5 min). Secondary endpoints included intraoperative PaCO2, minute ventilation and the use of vasoconstrictors.
  
  
  RESULTS
  Eleven patients were randomized to each group. Both groups were similar for age, body mass index, MELD, SOFA and APACHE II scores, baseline temperature, and duration of surgery. Immediately prior to reperfusion (Stage 3 - 5 min) the mean (SD) core temperature was higher in the Humidification Group compared to the Control Group: 36.0 °C (0.13) vs. 35.4 °C (0.22), p = 0.028. Repeated measured ANOVA showed that core temperatures over time during the stages of the transplant were higher in the Humidification Group compared to the Control Group (p < 0.0001). There were no significant differences in the ETCO2, PaCO2, minute ventilation, or inotropic support.
  
  
  CONCLUSIONS
  The humidified high flow CO2warming system was superior to standardized multimodal strategies in maintaining normothermia in patients undergoing OLT. Use of the device was feasible and did not interfere with any aspects of surgery. A larger study is needed to investigate if the improved thermoregulation observed is associated with improved patient outcomes.
  
  
  BACKGROUND
  ACTRN12616001631493 . Retrospectively registered 25 November 2016.
authors.affiliation: Department of Surgery, and Anaesthesia Perioperative and Pain Medicine Unit, The University of Melbourne, Melbourne, Australia. laurence.weinberg@austin.org.au.|Department of Anaesthesia, Austin Hospital, Heidelberg, Australia. laurence.weinberg@austin.org.au.
authors.forename: Laurence
authors.identifier: http://orcid.org/0000-0001-7403-7680
authors.initials: L
authors.lastname: Weinberg
authors.affiliation: Department of Anaesthesia, Austin Hospital, Heidelberg, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Huang
authors.affiliation: Department of Anaesthesia, Austin Hospital, Heidelberg, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Alban
authors.affiliation: Liver and Intestinal Transplant Unit, Austin Hospital and The University of Melbourne, Heidelberg, Australia.
authors.forename: Robert
authors.initials: R
authors.lastname: Jones
authors.affiliation: Perioperative and Pain Medicine Unit; The University of Melbourne, Victoria, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Story
authors.affiliation: Department of Surgery, and Anaesthesia Perioperative and Pain Medicine Unit, The University of Melbourne, Melbourne, Australia.|Department of Anaesthesia, Austin Hospital, Heidelberg, Australia.
authors.forename: Larry
authors.initials: L
authors.lastname: McNicol
authors.affiliation: Department of Anaesthesia, Austin Hospital, Heidelberg, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Pearce
mesh_terms: D000328:Adult; D001831:Body Temperature; D005240:Feasibility Studies; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D007035:Hypothermia / Q000209:etiology / Q000517:prevention & control*; D016031:Liver Transplantation / Q000009:adverse effects / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies
keywords: Anaesthesia; Liver; Nasopharyngeal; Temperature; Thermoregulation; Transplant