A simple improvised prehospital method to warm intravenous fluid

Use of warmed intravenous fluid by emergency medical services (EMS) for prehospital injured patients is recommended to avoid iatrogenic hypothermia. We hypothesized that an improvised heating method would significantly increase the temperature of an intravenous fluid bag in a simulated prehospital environment.

The change from baseline in the temperature of a 1-L intravenous fluid bag positioned above the vehicle windshield defroster vent was measured for 30 minutes using a thermocouple probe. Temperature changes were compared with a control fluid bag positioned on the vehicle console armrest. A total of 10 independent experiments were performed.

The defroster vent method increased intravenous fluid bag temperature from a mean starting temperature of 19.4°C (95% confidence interval [CI], 17.4°C-21.4°C) to a mean end temperature of 32.6°C (95% CI, 30.6°C-34.6°C) after 30 minutes. The temperature of a control intravenous fluid bag (mean starting temperature of 20.1°C; 95% CI, 19.0°C-21.2°C) exposed to a warmed (mean 33.2°C) passenger compartment changed little during the same time period (mean end temperature of 22.3°C; 95% CI, 19.4°C-25.2°C).

Convective warming of an intravenous fluid bag using the dashboard defroster vent significantly raised the fluid temperature. Such a method should be readily available to EMS or first responders.