An Analysis of the Temperature Change in Warmed Intravenous Fluids During Administration in Cold Environments

This nonhuman simulation study was conducted to determine the decrease in temperature that occurred to 1-L bags of normal saline in a cold environment. The bags were warmed to 39°C and administered through intravenous (IV) tubing at a set flow rate while in a cold environment. The goal was to determine if there was a significant decrease in fluid temperature from the bag to the catheter site. Three trials were completed at temperatures of 0°C, -7°C, -12°C, and 22°C (control). Each bag of normal saline was warmed to 39°C using the SoftSack IV Fluid Warmer (Smithworks Med Inc, Lindale, TX). Fluid was collected and temperatures recorded at 5-minute intervals. The results showed a statistically significant (P = .003) change in temperature between the IV bag and the administration site. The most rapid change occurred within the first 5 minutes. The temperature change was more significant with colder ambient temperatures, with an average of a 28.7°C difference at -7°C and -12°C after 30 minutes. It appears that the most significant heat loss occurs through the IV tubing itself. Therefore, it may be beneficial to insulate the tubing on a trauma patient receiving warmed IV fluids in a cold environment to help prevent hypothermia.