Resistive-polymer versus forced-air warming: comparable efficacy in orthopedic patients.
BACKGROUND
Several adverse consequences are caused by mild perioperative hypothermia. Maintaining normothermia with patient warming systems, today mostly with forced air (FA), has thus become a standard procedure during anesthesia. Recently, a polymer-based resistive patient warming system was developed. We compared the efficacy of a widely distributed FA system with the resistive-polymer (RP) system in a prospective, randomized clinical study.


METHODS
Eighty patients scheduled for orthopedic surgery were randomized to either FA warming (Bair Hugger warming blanket #522 and blower #750, Arizant, Eden Prairie, MN) or RP warming (Hot Dog Multi-Position Blanket and Hot Dog controller, Augustine Biomedical, Eden Prairie, MN). Core temperature, skin temperature (head, upper and lower arm, chest, abdomen, back, thigh, and calf), and room temperature (general and near the patient) were recorded continuously.


RESULTS
After an initial decrease, core temperatures increased in both groups at comparable rates (FA: 0.33 degrees C/h +/- 0.34 degrees C/h; RP: 0.29 degrees C/h +/- 0.35 degrees C/h; P = 0.6). There was also no difference in the course of mean skin and mean body (core) temperature. FA warming increased the environment close to the patient (the workplace of anesthesiologists and surgeons) more than RP warming (24.4 degrees C +/- 5.2 degrees C for FA vs 22.6 degrees C +/- 1.9 degrees C for RP at 30 minutes; P(AUC) <0.01).


CONCLUSIONS
RP warming performed as efficiently as FA warming in patients undergoing orthopedic surgery.
Brandt
Sebastian
S
University Department of Anaesthesia and Pain Therapy, Bern University Hospital, Inselspital, CH-3010 Bern, Switzerland. s.brandt@me.com
Oguz
Ruken
R
Hüttner
Hendrik
H
Waglechner
Günther
G
Chiari
Astrid
A
Greif
Robert
R
Kurz
Andrea
A
Kimberger
Oliver
O
D000328:Adult; D000768:Anesthesia, General / Q000009:adverse effects*; D001512:Bedding and Linens; D001833:Body Temperature Regulation; D004867:Equipment Design; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects*; D011108:Polymers; D011446:Prospective Studies; D017694:Rewarming / Q000295:instrumentation / Q000379:methods; D012881:Skin Temperature; D013997:Time Factors; D055815:Young Adult
D011108:Polymers