title: Preventing inadvertent perioperative hypothermia.
abstract: BACKGROUND
  25-90% of all patients undergoing elective surgery suffer from inadvertent postoperative hypothermia, i.e., a core body temperature below 36°C. Compared to normothermic patients, these patients have more frequent wound infections (relative risk [RR] 3.25, 95% confidence interval [CI] 1.35-7.84), cardiac complications (RR 4.49, 95% CI 1.00-20.16), and blood transfusions (RR 1.33, 95% CI 1.06-1.66). Hypothermic patients feel uncomfortable, and shivering raises oxygen consumption by about 40%.
  
  
  METHODS
  This guideline is based on a systematic review of the literature up to and including October 2012 and a further one from November 2012 to August 2014. The recommendations were developed and agreed upon by representatives of five medical specialty societies in a structured consensus process.
  
  
  RESULTS
  The patient's core temperature should be measured 1-2 hours before the start of anesthesia, and either continuously or every 15 minutes during surgery. Depending on the nature of the operation, the site of temperature measurement should be oral, naso-/oropharyngeal, esophageal, vesical, or tympanic (direct). The patient should be actively prewarmed 20-30 minutes before surgery to counteract the decline in temperature. Prewarmed patients must be actively warmed intraoperatively as well if the planned duration of anesthesia is longer than 60 minutes (without prewarming, 30 minutes). The ambient temperature in the operating room should be at least 21°C for adult patients and at least 24°C for children. Infusions and blood transfusions that are given at rates of >500 mL/h should be warmed first. Perioperatively, the largest possible area of the body surface should be thermally insulated. Emergence from general anesthesia should take place at normal body temperature. Postoperative hypothermia, if present, should be treated by the administration of convective or conductive heat until normothermia is achieved. Shivering can be treated with medications.
  
  
  CONCLUSIONS
  Inadvertent perioperative hypothermia can adversely affect the outcome of surgery and the patient's postoperative course. It should be actively prevented.
authors.affiliation: Clinic of Anesthesiology and Intensive Care Medicine, UKGM Giessen and Marburg, Marburg, Center for Anesthesiology, Emergency and Intensive Care Medicine, University Medical Center Göttingen, Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Department of Anaesthesia and Surgical Critical Care, Asklepios Clinic St. Georg, Hamburg, Department of Anaesthesiology and Intensive Care Medicine, Regio Kliniken Pinneberg.
authors.forename: Alexander
authors.initials: A
authors.lastname: Torossian
authors.forename: Anselm
authors.initials: A
authors.lastname: Bräuer
authors.forename: Jan
authors.initials: J
authors.lastname: Höcker
authors.forename: Berthold
authors.initials: B
authors.lastname: Bein
authors.forename: Hinnerk
authors.initials: H
authors.lastname: Wulf
authors.forename: Ernst-Peter
authors.initials: EP
authors.lastname: Horn
mesh_terms: D005858:Germany; D006801:Humans; D007035:Hypothermia / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control*; D016343:Monitoring, Intraoperative / Q000592:standards*; D019990:Perioperative Care / Q000009:adverse effects* / Q000592:standards*; D017410:Practice Guidelines as Topic; D017694:Rewarming / Q000592:standards*
references.citation: J Am Coll Surg. 2009 Oct;209(4):492-503.e1
references.pmid: 19801323
references.citation: J Clin Nurs. 2009 Mar;18(5):627-36
references.pmid: 19239533
references.citation: Anasthesiol Intensivmed Notfallmed Schmerzther. 2008 May;43(5):397-9
references.pmid: 18464218
references.citation: Anesthesiology. 2008 Jan;108(1):71-7
references.pmid: 18156884
references.citation: Eur J Anaesthesiol. 2007 Aug;24(8):668-75
references.pmid: 17425815
references.citation: AORN J. 2006 May;83(5):1090-104, 1107-13
references.pmid: 16722286
references.citation: N Engl J Med. 1997 Jun 12;336(24):1730-7
references.pmid: 9180091
references.citation: JAMA. 1997 Apr 9;277(14):1127-34
references.pmid: 9087467
references.citation: Anesthesiology. 1993 Sep;79(3):532-9
references.pmid: 8363079
references.citation: Cochrane Database Syst Rev. 2014;6:CD009908
references.pmid: 24895945
references.citation: AANA J. 2013 Oct;81(5):351-6
references.pmid: 24354070
references.citation: Anaesthesia. 2012 Jun;67(6):612-7
references.pmid: 22376088
references.citation: J Emerg Nurs. 2012 Nov;38(6):523-30
references.pmid: 23040166
references.citation: Anesth Analg. 2010 Mar 1;110(3):829-33
references.pmid: 20042439
references.citation: Anaesthesist. 2010 Sep;59(9):842-50
references.pmid: 20703440
references.citation: Anesth Analg. 2000 Mar;90(3):694-8
references.pmid: 10702459
references.citation: Eur J Anaesthesiol. 2012 Feb;29(2):70-4
references.pmid: 22037543
references.citation: Int J Evid Based Healthc. 2011 Dec;9(4):337-45
references.pmid: 22093385
references.citation: J Clin Nurs. 2011 Feb;20(3-4):305-16
references.pmid: 21219514
references.citation: Anaesthesia. 2010 Sep;65(9):942-5
references.pmid: 20649896
references.citation: J Perianesth Nurs. 2010 Dec;25(6):346-65
references.pmid: 21126665
references.citation: Anesthesiology. 1991 May;74(5):875-9
references.pmid: 2021204
references.citation: AORN J. 2013 Oct;98(4):354-66; quiz 367-9
references.pmid: 24075332
references.citation: Anaesthesia. 2003 Dec;58(12):1228-34
references.pmid: 14705689
references.citation: J Clin Anesth. 2003 Mar;15(2):119-25
references.pmid: 12719051
references.citation: Scand J Caring Sci. 2002 Jun;16(2):122-8
references.pmid: 12000664
references.citation: Anesth Analg. 2002 Feb;94(2):409-14, table of contents
references.pmid: 11812709
references.citation: Lancet. 2001 Sep 15;358(9285):876-80
references.pmid: 11567703
references.citation: Anesthesiology. 2001 Aug;95(2):531-43
references.pmid: 11506130
references.citation: Anesthesiology. 1991 May;74(5):815-9
references.pmid: 1673591