Convective air warming is more effective than resistive heating in an experimental model with a water dummy

Abstract

Trauma patients with accidental hypothermia have adverse outcomes when compared with normothermic patients. Studies with a small number of mild hypothermic volunteers suggested that convective warming is more effective than warming with 12 volt resistive heating blankets. In a laboratory study, we compared the warming effectiveness of two electric blankets and convective air warming. The average speed of convective rewarming during anaesthesia in patients is approximately 0.6 degree C per hour. Accordingly, calibration of the dummy was performed with increasing amounts of water during convective warming until we reached a temperature gain of 0.6 degree C per hour. The following warming experiments were performed: 12 volt electric warming blanket (SH6012, Hella); 12 volt electric warming blanket (Thermamed, whole-body blanket); convective air warming (Warm Touch, Mallinckrodt, whole-body blanket). Each experiment was repeated four times. The temperature development was measured and recorded online. Convective warming increased the dummy temperature 0.6 degree C per hour, Thermamed 0.3 degree C per hour (P<0.001 versus convective warming) and two Hella blankets 0.2 degree C per hour (P<0.001 versus convective warming). Our laboratory investigation confirmed the superiority of convective warming over resistive heating. Efforts should be made to incorporate convective warming into the out-of-hospital treatment of trauma patients.

Resistive-Heating or Forced-Air Warming for the Prevention of Redistribution Hypothermia

“…In an experimental model with a water dummy, the superiority of convective warming over resistive heating has been demonstrated. 14 In a recent study in healthy volunteers, heating efficacy and core rewarming rates were similar when using full-body forced-air and full-body resistive polymer heating. 16 The group that did not undergo prewarming only presented with mild intraoperative hypothermia.…”

“…10,11 Several reusable resistive-warming systems have been developed recently. 10,[12][13][14][15][16] They are based on carbon fiber technology and have a low-voltage, direct current power supply. In this study, we assessed the efficacy of a resistiveheating system or a forced-air warming system for 30 minutes of prewarming in comparison with a control group that received the current standard of care.…”

User Trust levels and Adoption of Mobile Payment Systems in China: An Empirical Analysis

“…Perceived usefulness and perceived ease of use play a vital role in forming online trust (Chellappa, 2008; Nijssen et al, 2016; Qu et al, 2018). Moreover, mobility and reputation directly influence users’ trust in mobile payment usage intention (Alshare & Mousa, 2014; Gerhardt et al, 2010; Ittner et al, 2004; Kim, 2016; Luo et al, 2014). In the current study, the authors investigated the antecedents of China’s government monitoring in combination with trust.…”

Patient Warming Device for Casualty Care

“…Low-power conductive devices cannot maintain effective temperatures while under thermal load. 23 The cool body and surrounding environment quickly draw heat away from the coverlet faster than the power supply can replenish it. 26,27 Convective warming systems have been used safely for over ten years, with no published reports of injuries.…”