title: Wet forced-air warming blankets are ineffective at maintaining normothermia.
abstract: BACKGROUND
  Forced-air warming systems have proven effective in preventing perioperative hypothermia. To date, reported adverse events relate primarily to overheating and thermal injuries. This study uses a simple model to show that forced-air warming blankets become ineffective if they get wet.
  
  
  METHODS
  Temperature sensor probes were inserted into three 1-liter fluid bags. Group C bags served as the control. Groups D (dry) and W (wet) bags were placed on Bair Hugger(R) Model 555 (Arizant Healthcare, Inc., Eden Prairie, MN, USA) pediatric underbody blankets. The warming blanket for Group W bags was subsequently wet with irrigation fluid. Temperature was documented every 5 min. This model was repeated two times for a total of three cycles. Statistical analysis was performed using anova for repeated measures.
  
  
  RESULTS
  Starting temperatures for each model were within a 0.3 degrees C range. Group C demonstrated a steady decline in temperature. Group D maintained and slightly increased in temperature during the observation period, while Group W exhibited a decrease in temperature at a rate similar to Group C. These results were significant at P < 0.005.
  
  
  CONCLUSIONS
  A wet forced-air warming blanket is ineffective at maintaining normothermia. Once wet, the warming blanket resulted in cooling similar to the control group.
authors.affiliation: Department of Anesthesiology, University of North Carolina Hospitals, Chapel Hill, NC, USA. elin@aims.unc.edu
authors.forename: Erica P
authors.initials: EP
authors.lastname: Lin
authors.forename: Kathleen
authors.initials: K
authors.lastname: Smith
authors.forename: Robert D
authors.initials: RD
authors.lastname: Valley
mesh_terms: D001512:Bedding and Linens / Q000009:adverse effects; D004867:Equipment Design; D004868:Equipment Failure; D007035:Hypothermia / Q000517:prevention & control*; D008954:Models, Biological; D017694:Rewarming / Q000009:adverse effects / Q000295:instrumentation*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000009:adverse effects*
chemical_list: D014867:Water