A systematic review of the effectiveness of cutaneous warming systems to prevent hypothermia

Aims. To retrieve and critique recent randomised trials of cutaneous warming systems used to prevent hypothermia in surgical patients during the intraoperative period and to identify gaps in current evidence and make recommendations for future trials. Background. Hypothermia affects up to 70% of anaesthetised surgical patients and is associated with several significant negative health outcomes. Design. Systematic review using integrative methods. Methods. We searched CINAHL, EMBASE, Cochrane Register of Controlled Trials and Medline databases (January 2000-April 2007) for recent reports on randomised controlled trials of cutaneous warming systems used with elective patients during the intraoperative period. Inclusion criteria. We included randomised control trials examining the effects of cutaneous warming systems used intraoperatively on patients aged 18 years or older undergoing non-emergency surgery. Studies published in English, Spanish or Portuguese with a comparison group that consisted of either usual care or active cutaneous warming systems without prewarming were reviewed. Results. Of 193 papers initially identified, 14 studies met the inclusion criteria. There was moderate evidence to indicate that carbon-fibre blankets and forced-air warming systems are equally effective and that circulating-water garments are most effective for maintaining normothermia during the intraoperative period. Few trials reported costs. Conclusions. Carbon-fibre blankets and forced-air warming systems are effective and circulating-water garments may be preferable. Future research should measure the direct and indirect costs associated with competing systems. Relevance to clinical practice. Nurses can use this review to inform their selection of warming interventions in perioperative nursing practice. They can also assess other factors such as nursing workload, staff training and equipment maintenance, which should be incorporated into future research.