Hypothermia

Recommendations vary.

The prehospital recommendation in Wilderness Medicine is 37 to 41 (98.6 to 105.8). Wilkerson, in Medicine for Mountaineering, noted how inefficient the transfer of heat is even when using fluid heated to 104. Thelan's Critical Care Nursing notes a range of warmed IV fluid of 37 to 43 (98.6 to 109.4).

Rewarming with IV fluid should be only one mode used within an entire complex of tactics for the moderate to severe patient: increase room temp, BairHugger (sp?), warm packs, etc.

Clearly, the ultimate choice depends on the MDs judgement of severity and preference; but they count on us as their constant monitors.

Most good EDs have rapid infusers with a warming circuit. This is the time of year to get reaquainted with them!

Why do you ask? BTW, what sources did you look in without success? True I'm familiar with the topic (I teach it every winter to my SAR team), but it took me all of five minutes to find info without even looking on the 'net. I bet the internet would be even faster.

Thank you for your response. I really appreciate it. I had a patient the other day who was hypothermic and was treated in the ER and ICU before he was transferred to the floor. I was looking at the treatment for hypothermia and it said Bairhugger and warm NS. It was easy to find info on the Bair hugger, but was unable to find info on the actual temp of the NS. I looked in my textbook and on various websites, but it just said "warm" everywhere I looked. I figured it was because it depended on the physician, but I just wanted to ask someone on here for clarification. Thank you for answering!

If they were out of the ED and out of the ICU, then 'warm NS' probably means just what is in the bag warmer. I'm guessing that you have (as we do) a fluid warming cabinet stocked with the most used fluids. Some are stand-alone (such as ours, because we use a lot), but some are just a compartment in a blanket warmer. I wouldn't think extraordinary warming is needed once the patient has been around that long.

In the ED we have several liter bags of 0.9%NS kept at 102F - this is used more for pt comfort, slight chills, or frail elderly with little subq (these pts get chilly really fast, especially in the arm that has IVF running). For example, I had a pt who was involved in a motorcycle crash come in to our ED - it was a chilly morning, and he was soaking wet and was shivering. He wasn't hypothermic, but getting those cold wet clothes off, giving warmed blankets, and running 2 liters of warmed 0.9% NS made him much more comfortable and took away his chills.

For true hypothermia, we place a foley temp catheter to monitor temperature and output (we use a temp catheter because you can't reliably take their temp orally).

We start warming the pt by using a bair hugger, which is a disposable plastic blanket that gets hooked up to a hot air blower that can be set at 3-4 different temp levels (ambient, low, warm, and hot; I can't remember what the "low" setting is, but I think that the "warm" setting is 100.4F and "hot" is 107.6F).

We also use a "Ranger" fluid warmer, and we use specialized large bore IV tubing with two IV spikes along with an inline blood filter. All the machine does is deliver warmed fluids and blood products - it isn't a pump where you can control the rate. There's 2-3 roller clamps on the tubing, along with multiple "clips" (sorry, I don't know the technical name) that you can close to control which fluid you want to infuse as well as to stop all fluids from running. It heats fluids/blood products to 105.8F and can deliver nearly 30L/hr (according to the manufacturer's website).

Sometimes hypothermia can be a good thing because its the body's way of preserving vital organ function. So its important to find the cause and treat accordingly (septic, hypoglycemic, out in the snow, and so on). Some institutions actually induce hypothermia post-resuscitation and use cold IVF, cold air, ice, etc to chill the pt - it is thought that hypothermia slows down oxygen consumption and lessens apoptosis, allowing the body to recover and maintain brain function. These pts are paralyzed to prevent shivering, which would increase oxygen consumption and compound the problem.

Long story short: warmed IVF cannot be used alone to treat true hypothermia; you need to use both external and internal warming interventions. IVF kept in a blanket warmer will lose heat fast, so its best to use a fluid warming device to keep the temp constant.