title: Warming before and after epidural block before general anaesthesia for major abdominal surgery prevents perioperative hypothermia: A randomised controlled trial.
abstract: BACKGROUND
  Epidural analgesia (EDA) is known to be an independent risk factor for perioperative hypothermia and its many known adverse effects. Combined general and epidural anaesthesia decreases intraoperative core temperature more rapidly than general anaesthesia alone. Hence, adequate warming procedures are needed for these patients.
  
  
  OBJECTIVE
  We evaluated the effects of active skin-surface warming before and/or after initiation of EDA during general anaesthesia as a procedure to prevent perioperative hypothermia.
  
  
  METHODS
  A randomised controlled trial.
  
  
  METHODS
  Department of Anaesthesiology in a general hospital in Germany from January 2013 until August 2014.
  
  
  METHODS
  After obtaining written informed consent, we included 99 adult patients undergoing elective major abdominal surgery under combined general anaesthesia and EDA with an expected duration of surgery of at least 120 min. Patients were excluded if they were under 18 years of age, classified as American Society of Anesthesiologists' physical status 4 or higher or if patients refused EDA.
  
  
  METHODS
  Patients were randomly assigned to one of three groups and received either only passive insulation, 15 min of active air-forced warming after EDA and before induction of general anaesthesia, or two periods, each of 15 min, of active air-forced warming before and after EDA. Core and skin temperatures were measured at several time points throughout the study.
  
  
  METHODS
  The primary outcome measure was the incidence of hypothermia on arrival in the ICU. The secondary outcome measure was the incidence of postoperative shivering. In addition, the perioperative change in body core temperature was recorded.
  
  
  RESULTS
  Without prewarming (n = 32), 72% of patients became hypothermic (<36°C) at the end of anaesthesia. Fifteen minutes of warming after insertion of the epidural catheter and before initiation of general anaesthesia reduced the incidence of postoperative hypothermia to 6% (n = 33). After two periods of 15 min of warming before and after insertion of the epidural catheter, no patient became hypothermic (n = 34). Prewarming in either 'warming' group prevents the initial temperature drop which was observed in the control group.
  
  
  CONCLUSIONS
  Warming for 15 min before and after initiation of EDA in patients receiving combined anaesthesia is effective in preventing postoperative hypothermia.
  
  
  BACKGROUND
  This trial was registered with ClinicalTrials.gov (identifier: NCT01795482).
authors.affiliation: From the Department of Anaesthesiology, Regio Klinikum Pinneberg, Pinneberg (E-PH); Department of Anaesthesiology, Asklepios Clinic St. Georg Hamburg, Hamburg (BB); and Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany (OB, TI, RB, S-KL, JH).
authors.forename: Ernst-Peter
authors.initials: EP
authors.lastname: Horn
authors.forename: Berthold
authors.initials: B
authors.lastname: Bein
authors.forename: Ole
authors.initials: O
authors.lastname: Broch
authors.forename: Timo
authors.initials: T
authors.lastname: Iden
authors.forename: Ruwen
authors.initials: R
authors.lastname: Böhm
authors.forename: Svea-Kristina
authors.initials: SK
authors.lastname: Latz
authors.forename: Jan
authors.initials: J
authors.lastname: Höcker
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000368:Aged; D015360:Analgesia, Epidural / Q000009:adverse effects*; D000768:Anesthesia, General / Q000009:adverse effects*; D017558:Elective Surgical Procedures; D005260:Female; D005858:Germany; D006769:Hospitals, General; D006801:Humans; D006979:Hyperthermia, Induced; D007035:Hypothermia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D061646:Operative Time; D019990:Perioperative Care / Q000379:methods*; D012307:Risk Factors; D012768:Shivering; D012881:Skin Temperature; D013997:Time Factors; D016896:Treatment Outcome