Comparison of Three Warming Devices for the Prevention of Core Hypothermia and Post-Anaesthesia Shivering

Abstract

The efficacy of forced air warming with a surgical access blanket in preventing a decrease in core temperature during anaesthesia and post-anaesthesia shivering (PAS) was compared with two widely used interventions comprising forced air warming combined with an upper body blanket, and a circulating water mattress, in a prospective, randomized double-blind study. A total of 90 patients undergoing total abdominal hysterectomy were studied, 30 in each group. Core temperature was measured 15, 30, 45, 60, 90 and 120 min after induction of anaesthesia. PAS was evaluated every 5 min after emergence from anaesthesia over a period of 1 h. Core temperature fell in all three groups compared with the baseline, but forced air warming using a surgical access blanket was more effective than the other warming methods in ameliorating the temperature decrease. The surgical access blanket was also superior to the circulating water mattress in reducing PAS.

Peri‐operative warming devices: performance and clinical application

“…This is particularly important for forced-air warming because air has a very low specific heat capacity. Increased coverage can explain the superior heat transfer ability of lower body blankets in comparison with smaller upper body blankets [64], and why surgical access blankets have significantly improved intra-operative temperature profiles when compared with upper body blankets [67].…”

“…Due to the greater specific heat capacity [108] and thermal conductivity [109] of water, it is, in theory, a more effective medium to transfer heat when compared with air. This theoretical advantage is not translated into a clinical one as all of the trials comparing the two different warming modalities favoured forced-air warming [53][54][55]67].…”

Effectiveness of cutaneous warming systems on temperature control: meta‐analysis

“…Systems vary in terms of whether heat is provided to the upper or lower body, full body or surgical site only (Motamed et al 2000, Ihn et al 2008, Insler et al 2008. Quieter convective warming systems (such as WarmAir Model 135Ô, Cincinnati Sub Zero, Cincinnati, OH, USA) have also recently been developed (Wagner et al 2008).…”

Active cutaneous warming systems to prevent intraoperative hypothermia: a systematic review

“…Circulating-water mattress was compared with the forced-air warming system in four clinical trials (20)(21)(22)(23) .…”

“…The other three studies (20)(21)(22) reported that the forced-air warming system was better at preventing hypothermia (abdominal surgeries and general anesthetics). Three of the four clinical trials presented a Jadad score of 3 (moderate) (20)(21)(22) and one scored a 2 (low quality) (23) .…”