Randomized non-inferiority trial of the vitalHEAT temperature management system vs the Bair Hugger warmer during total knee arthroplasty.
OBJECTIVE
Intraoperative and postoperative hypothermia occur commonly; mild hypothermia (34-36 degrees C) is associated with adverse events. The use of perioperative warming devices has become routine, but currently available active warming devices may be limited in certain circumstances. The vitalHEAT Temperature Management System provides conductive warming (circulating warm water) around a single extremity together with a vacuum that is applied to the limb. In this randomized trial, we tested the hypothesis that the vitalHEAT system is non-inferior to the Bair Hugger during unilateral total knee arthroplasty.


METHODS
Physical status I-III patients who were >or=18 yr-old were eligible to participate. The patients were randomly assigned to the vitalHEAT system (n = 30) or to Bair Hugger (n = 25) warming. Intraoperative and first recovery room temperatures were recorded in both groups.


RESULTS
The baseline characteristics of the groups were similar. In terms of the primary outcome measure, i.e., sublingual temperature measured within 10 min of recovery room arrival, the vitalHEAT system did not meet the criterion for non-inferiority. Specifically, the confidence interval for the difference between means included the non-inferiority margin (-0.5 degrees C). In terms of the secondary measures, i.e., intraoperative esophageal temperatures, the vitalHEAT system also underperformed compared with the Bair Hugger.


CONCLUSIONS
The vitalHEAT system may have advantages over convective warming systems because it requires a much smaller body surface area; however, in this study of warming during total knee arthroplasty, it underperformed when compared with the Bair Hugger, especially around and after the time of tourniquet release.


BACKGROUND
NCT00711867.
Trentman
Terrence L
TL
Department of Anesthesiology, Mayo Clinic Arizona, Phoenix, AZ 85054, USA. trentman.terrence@mayo.edu
Weinmeister
Kent P
KP
Hentz
Joseph G
JG
Laney
Mary B
MB
Simula
Daniel V
DV
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001830:Body Surface Area; D001831:Body Temperature; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000517:prevention & control*; D007430:Intraoperative Care / Q000379:methods; D007431:Intraoperative Complications / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000517:prevention & control; D017694:Rewarming / Q000295:instrumentation / Q000379:methods*