Hello!
I was following this thread and thought I might be able to help out. I've done research on both warm and cold IV fluids. I've talked to the R&D department at Baxter Healthcare (they make the majority of IV fluids in the US). To echo what the others have said, the temperature really does not affect the fluid per se. The temperature variations DO affect the bag that the fluid is held in. Now, Baxter and others will not officially endorse allowing fluids to go below 2 degrees C or above 42 degrees C. Using fluids outside of these ranges are considered off-label use. The problem with freezing temperatures is the possibility for the bag to develop microtears in the plastic allowing for contaminants to enter (or fluid to leave). The problem with temperatures above 42 degrees C is the possibility for the breakdown of the plastic byproducts of the bag into the fluid.
The importance of warmed IV fluids cannot be over emphasized. Many of our patients coming into Level 1 Trauma Centers are mildly to moderately hypothermia on a routine basis. A 2006 study by the Joint Theater Trauma System (JTTS) found that 66% of combat casualities arrived at the hospital hypothermic. The same study found that there is a 20% increase in mortality if the core temperature on arrival is below 95 degrees F, and an 80% increase in mortality if the temperature is below 95 degrees F on arrival.
Like was mentioned in an earlier post, the problem with using warming methods (defroster, heating pads, gel packs, microwave [God forbid], etc) is the lack of control of the temperature of the fluid. All of those methods have been found to have the ability to make fluid so hot that it can potentially burn the patient. The Level 1 is an effective way to warm patients, but it has no use in the pre-hospital arena (it very big and bulky and has to be wheeled around). Plus, the Level 1 is an "all or none" device. You're either giving nothing or a couple liters every few minutes. Lastly the Level 1 cost about $15,000-$18,000 a pop.
At the helicopter we have a lot of patients that are either hypothermia or have a huge potential to become rapidly hypothermia. One of the devices that we found on the market has been used extensively by the military and and is now being used by civilian air medical services and 911 services is an inline IV fluid (and blood) warmer called the Thermal Angel. It is talked about in the military PHTLS book and is in the TCCC protocol for hypothermia prevention and treatment. The Thermal Angel heats the IV fluid almost right at the site of insertion so there is no heat loss through the tubing. Like someone mentioned above, it does no good to heat the bag when the tubing is left exposed. We are getting ready to start using the Thermal Angel on the helicopter to prevent and treat hypothermia in nearly all of our patients. You might want to Google the Thermal Angel and check it out.
Hope this helps!
Mike
