title: Postoperative hemodynamic and thermoregulatory consequences of intraoperative core hypothermia.
abstract: OBJECTIVE
  To evaluate the postoperative hemodynamic and thermoregulatory consequences of intraoperative core hypothermia.
  
  
  METHODS
  Prospective, randomized clinical trial.
  
  
  METHODS
  Operating room and postanesthesia care unit of a university hospital.
  
  
  METHODS
  74 healthy, ASA status I, II, and III patients (average age 58 yrs) undergoing elective colon surgery.
  
  
  METHODS
  Patients were randomly assigned to be kept normothermic or approximately 2.5 degrees C hypothermic during surgery. Anesthesia was maintained with isoflurane, nitrous oxide, and fentanyl. Postoperatively, surgical pain was treated with patient-controlled analgesia (PCA) opioid.
  
  
  RESULTS
  An observer blinded to group assignment and core temperatures evaluated shivering, thermal comfort, surgical pain, heart rates (HRs), and blood pressures (BPs) during the first six postoperative hours. Morphometric characteristics, oxygen saturation, fluid balance, PCA-administered opioid, and visual analog pain scores were comparable in the two groups. Hypothermic patients felt uncomfortably cold during recovery, and their postoperative core temperatures remained significantly less than in the normothermic patients for more than four hours. Peripheral vasoconstriction and shivering were common in the hypothermic patients but rare in those kept normothermic. HRs and BPs were comparable in the two groups.
  
  
  CONCLUSIONS
  These data confirm that the effects of intraoperative hypothermia on postoperative HR and BP are modest in relatively young, generally healthy patients. In contrast, intraoperative hypothermia caused substantial postoperative thermal discomfort, and full recovery from hypothermia required many hours. Delayed return to care normothermia apparently resulted largely from postoperative thermoregulatory impairment.
authors.affiliation: Department of Anesthesia and Intensive Care, University of Vienna, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Kurz
authors.forename: D I
authors.initials: DI
authors.lastname: Sessler
authors.forename: E
authors.initials: E
authors.lastname: Narzt
authors.forename: A
authors.initials: A
authors.lastname: Bekar
authors.forename: R
authors.initials: R
authors.lastname: Lenhardt
authors.forename: G
authors.initials: G
authors.lastname: Huemer
authors.forename: F
authors.initials: F
authors.lastname: Lackner
mesh_terms: D016058:Analgesia, Patient-Controlled; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation; D001794:Blood Pressure; D001831:Body Temperature; D001833:Body Temperature Regulation; D003080:Cold Temperature; D003106:Colon / Q000601:surgery; D017558:Elective Surgical Procedures; D005260:Female; D006339:Heart Rate; D006801:Humans; D007036:Hypothermia, Induced; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010149:Postoperative Pain / Q000517:prevention & control; D010465:Perception; D011182:Postoperative Care; D011446:Prospective Studies; D012768:Shivering; D016037:Single-Blind Method; D014661:Vasoconstriction