title: Effect of a heat and moisture exchanger on heat loss in isoflurane-anesthetized dogs undergoing single-limb orthopedic procedures.
abstract: OBJECTIVE
  To determine whether a heat and moisture exchange device (HME) prevents a decrease in body temperature in isoflurane-anesthetized dogs undergoing orthopedic procedures.
  
  
  METHODS
  Blinded randomized controlled clinical trial.
  
  
  METHODS
  60 privately owned dogs weighing at least 15 kg (33 lb).
  
  
  METHODS
  Dogs were randomly assigned to 1 of 3 treatment groups (n = 20/group): HME placed immediately after anesthetic induction with isoflurane, after transfer to the operating room, or not at all. The device consisted of a hygroscopic filter placed between the endotracheal tube and the Y piece of the anesthesia circuit. Each dog was positioned on a circulating warm water blanket and had a forced-air warming blanket placed over its body. Body temperature was monitored after transfer to the operating room with a probe placed in the thoracic aspect of the esophagus.
  
  
  RESULTS
  Study groups did not differ significantly with respect to body weight, body condition score, reproductive status, breed, surgical procedure, preoperative sedative and opioid administration, anesthetic induction drug, local nerve block technique, or operating room assignment. There were no significant differences among groups in esophageal temperature variables, interval between anesthetic induction and surgery, surgery duration, anesthesia duration, or oxygen flow rate. However, the relationship between temperature delta and body weight was significant and relevant (R(2) = 0.23), as was the association between temperature nadir and body weight (R(2)= 0.10). As body weight increased, the temperature delta decreased and temperature nadir increased. No other significant relationships were identified.
  
  
  CONCLUSIONS
  Inclusion of an HME in healthy dogs undergoing anesthesia for an elective orthopedic surgery did not facilitate maintenance of body temperature throughout the procedure.
authors: Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
authors: Erik H
authors: EH
authors: Hofmeister
authors: Benjamin M
authors: BM
authors: Brainard
authors: Christina
authors: C
authors: Braun
authors: Juliana P
authors: JP
authors: Figueiredo
mesh_terms: D000768:Anesthesia, General / Q000662:veterinary*; D018685:Anesthetics, Inhalation; D000818:Animals; D001833:Body Temperature Regulation; D004285:Dogs; D005260:Female; D006358:Hot Temperature / Q000627:therapeutic use*; D007530:Isoflurane; D008297:Male; D009873:Operating Rooms; D009985:Orthopedics / Q000662:veterinary*; D013997:Time Factors; D014867:Water
chemical_list: D018685:Anesthetics, Inhalation; D014867:Water; D007530:Isoflurane