title: Assessing the influence of insulation on intravenous fluid infusion temperature.
abstract: OBJECTIVE
  Inducing therapeutic hypothermia using chilled saline in resuscitated cardiac arrest patients has been shown to be feasible and effective. Limited research exists assessing the efficiency of this cooling method. The objective of this study was to assess the change in temperature of 4°C saline upon exiting an infusion set in the laboratory setting while varying conditions of fluid delivery.
  
  
  METHODS
  Efficiency was studied by assessing change in fluid temperature (°C) during the infusion under four laboratory conditions. Each condition was performed four times using 1-L bags of normal saline. Fluid was infused into a 1000-mL beaker through 10 gtt/mL tubing. Flow rate was controlled using a tubing clamp and in-line transducer with a flow meter, while temperature was continuously monitored in a side port at the terminal end of the intravenous (IV) tubing using a digital thermometer. The four conditions included different insulation methods. Descriptive statistics and analysis of variance were performed to assess changes in fluid temperature.
  
  
  RESULTS
  The mean (±SD) fluid temperature at time 0 was 3.2°C (95% confidence interval [CI] = 3.0 to 3.4 °C) with no significant difference in starting temperature between groups (p = 0.45). When flow rate was constant, it was determined that fluid temperatures were significantly cooler when infused using a chilled, gel-filled sleeve around the saline bag (p < 0.006).
  
  
  CONCLUSIONS
  In a laboratory setting, the most efficient method of infusing cold fluid appears to be a method that both keeps the bag of fluid insulated and infused at a faster rate.
authors.affiliation: The Center for Prehospital Medicine, Carolinas Medical Center, Charlotte, NC, USA. jonst@medic911.com
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Studnek
authors.forename: John A
authors.initials: JA
authors.lastname: Watts
authors.forename: Steven
authors.initials: S
authors.lastname: Vandeventer
authors.forename: David
authors.initials: D
authors.lastname: Pearson
mesh_terms: D004867:Equipment Design; D006323:Heart Arrest / Q000628:therapy; D006801:Humans; D007036:Hypothermia, Induced / Q000295:instrumentation* / Q000379:methods; D007262:Infusions, Intravenous / Q000295:instrumentation*; D007552:Isotonic Solutions / Q000008:administration & dosage; D012680:Sensitivity and Specificity; D012965:Sodium Chloride / Q000008:administration & dosage*; D013696:Temperature
chemical_list: D007552:Isotonic Solutions; D012965:Sodium Chloride