title: Do heated humidifiers and heat and moisture exchangers prevent temperature drop during lower abdominal surgery?
abstract: OBJECTIVE
  To compare the effects of using a heated humidifier (HH), a heat and moisture exchanger (HME), or no warming device in maintaining body temperature during surgical procedures of 1 to 4 hours' duration.
  
  
  METHODS
  A randomized, controlled study.
  
  
  METHODS
  Operating room, Thomas Jefferson University Hospital, Philadelphia, PA.
  
  
  METHODS
  51 ASA physical status I, II, and III patients, age 16 to 69 years, scheduled for a variety of lower abdominal procedures under general endotracheal anesthesia anticipated to last 1 to 4 hours.
  
  
  METHODS
  We randomly assigned patients to receiving an HH, an HME, or no warming device during the procedure. We then measured the patient's sublingual temperature every 5 minutes prior to induction, every 15 minutes intraoperatively, and every 15 minutes postoperatively until he or she was discharged from the postanesthesia care unit, (PACU). We also measured the esophageal temperature every 15 minutes intraoperatively.
  
  
  RESULTS
  Sublingual temperature or esophageal temperature probes placed at the site of maximal heart tones indicated that the patients' temperatures dropped significantly from baseline values in all three groups during the first 60 minutes of surgery, then remained constant during the next 120 minutes of surgery. Patients who had no warming device shivered and felt cold significantly more often than patients in the HH group but not more often than patients in the HME group. There was no difference in shivering between the HH and HME groups. The patients who received an HH tended to have a higher temperature (a mean of 0.5 degrees C) throughout the study, but this did not reach statistical significance.
  
  
  CONCLUSIONS
  Results indicate that these warming devices provide little benefit in preventing a temperature drop during procedures of 1 to 4 hours' duration, although patients with an HH tended to have a higher temperature than those with an HME or no device.
authors.affiliation: Department of Anesthesiology, Jefferson Medical College, Philadelphia, PA.
authors.forename: M E
authors.initials: ME
authors.lastname: Goldberg
authors.forename: R
authors.initials: R
authors.lastname: Epstein
authors.forename: F
authors.initials: F
authors.lastname: Rosenblum
authors.forename: G E
authors.initials: GE
authors.lastname: Larijani
authors.forename: A
authors.initials: A
authors.lastname: Marr
authors.forename: J
authors.initials: J
authors.lastname: Lessin
authors.forename: M
authors.initials: M
authors.lastname: Torjman
authors.forename: J
authors.initials: J
authors.lastname: Seltzer
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000762:Anesthesia Recovery Period; D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D001831:Body Temperature; D001833:Body Temperature Regulation; D004867:Equipment Design; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D006813:Humidity; D007035:Hypothermia / Q000517:prevention & control*; D008875:Middle Aged; D009873:Operating Rooms; D012768:Shivering; D013821:Thermometers; D013997:Time Factors