Active Warming

[Chief1C]

I'll add some next time I get a chance to log into my trip sheet bank. Had a call, true holy shit how are you alive, type deal. Marked with multi organ failure in the month afterward. It was a good learning experience call. I can't remember the nitty gritty details, so I'll wait till later to post it.

[DwayneEMTP]

Thanks all. I've never really given that much thought despite having worked in some pretty cold places.

Is there ever an indication for an extremely rapid rewarming I wonder? Say, 100F bath?

It's not important, and I'm not sure if it's an appropriate question for this thread...Was just thinking of zebras...

[Lotus]

Zebras like baths that hot? Owo

[Arctickat]

None that I can recall Dwayne. There is indication for rapid cooling during severe heat stroke because of the potential for brain damage, but I can think of nothing requiring "rapid" rewarming, However, thawing a frostbitten body part requires immersion in water at 104°F or 40°C and lots of pain meds.

[DartmouthDave]

Hello,

I am use to the term 'active' and 'passive' rewarming.

We use 'passsive' rewarming for mild to moderate hypothermia patients with a goal of .5C increase an hour.

'Active' rewarming are things like ECMO, warm intrathorasic lavages abd abdominal lavages. Patients below 32-32C (I think) are unable to generate heat without assistance. I have never seen this done. But, I have had a few very cold patients that have be helped by these interventions.

Cheers

Edited April 19, 2012 by DartmouthDave

[Arctickat]

You're partially correct. There are two types of Active rewarming. Essentially, Active Rewarming is the process of reversing hypothermia using artificially applied heat to warm the patient. Active Internal Rewarming is what you're describing...prehospitally, warmed IV solutions would be Active Internal Rewarming. This is reserved for severe hypothermia patients, usually below 30° C and unresponsive. Active External Rewarming is what we're more familiar with...warm blankets, hot packs in the pits and crotch, body to body contact are all examples.

Passive rewarming is simply removing cold and wet clothing and putting on dry clothes.

Edit;

To add to Passive, removing the patient from the cold environment and changing clothes will reverse the hypothermia. Essentially, passive rewarming only works when the body still has the ability to thermoregulate. When the body gets to the point that Thermoregulation is no longer working, Active rewarming must take place. Remember, ambient room temps are 72°F (20°C) If the body is incapable of thermoregulation it will continue to cool to room temp rather than warm back up to normal body temps. A good indication that the body has lost the ability to thermoregulate is that the patient is no longer shivering. This typically occurs around 33°C.

Honestly, I love how Hypothermia and Hyperthermia mirror one another like that.

Edited April 19, 2012 by Arctickat

[Chief1C]

So... Anyhoo. I just got some time to myself, b/c I really don't want to do the CQI forms, they're a couple weeks overdue anyway. What will an hour hurt? (I'm not the one that is supposed to do them - but I am - so that should count for something, right?)

My first patient, where the only problem was hypothermia. The reason that hypothermia came to be the problem, was unknown. Patient was walking from a parking spot, to a cabin in a wilderness area, no phone service, but was supposed to walk back out and call family from a seasonal place near by. Phone call never came, family got worried, sent someone to check. Said bystander located the victim in about 15" of icy snow, about a mile into the woods.

Timing, I could figure the person may have been exposed for 8 to 13 hours. A little bit of SAR expertise, and you look for signs of recent activity. The foot prints and tire tracks were all frozen solid, so they were not recent imprints, and the ice was clean, not muddy. The snow around the victim, was also frozen, and not disturbed, so there had been no movement for some time as well. Temperature at the time was 18F (-7C), with light wind, sun and of course snow cover. There were no barriers to obstruct the wind. The forecast temperature for the preceeding evening, was to be around 10F (-12C).

The patient was clothed in blue jeans, a long sleeve, light shirt and a hunting jacket; and the clothing was wet or frozen solid. Skin that was in contact with clothing, which rested upon snow or ice, was bright red and frozen (like - yanno - firm/frozen). Extend your hand flat, and the fingers back, and press on your palm.. Now picture it excessively cold and moist, that would be how the skin felt. Clothing was of course removed.....

Do you like suspense?

Because I have a call. I'll get back to you.

[Chief1C]

Continuing...

Didn't know how the person came to be laying there, and the snow did have several inches of solid ice on top from an ice/sleet storm.. So, we immobilized, and carefully placed on a big fluffy blanket on a spine board. Now totally nude; covered with another big fluffy blanket and then a Ready Heat blanket. Wrapped heat packs in pillow cases we butchered and put them in all the common areas for transport out on foot. Got the cocoon thing all wrapped up and carried. Our hands were now white and painfully cold, b/c gloves certainly don't help on a cold day. Put the monitoring device in place....rectally. fun fun. It's a wired device with a probe, slip a probe cover on it, lube it, and gently...yanno.. Core temp was 88.1F (31.1C).

Patient was not responding, pupils were constricted and non reactive. Could not obtain radial or femoral pulses, the skin was too stiff to obtain a good carotid pulse, so I listened w/ scope. HR was 66 and very irregular. Initial NIBP was 167/120. GCS was marked as 1-1-1. As the patient warmed up, the patient began furiously scratching at the neck area, and the hands were wrapped with towels. Otherwise there probably would have been no skin left. Respiratory rate was 20 and and lung sounds were clear, the patient was maintaining the airway fine (I'm using general terms to avoid mentioning a sex), had "warmed" oxygen flowing at 15 by mask.

We sat at a field awaiting an aircraft, as the nearest ER that could handle such was at least 2hr by ground w/ road conditions and as far out in the boonies as we were. Took maybe 5min from the time the patient was out and loaded up; till the chopper was on the ground. In that time, the pulse dropped to 48, BP was 60/44, and respiratory rate was now 10 and shallow. Placed an NPA, and began bagging.. and then the chopper staff took over. Had to do an IO, as they couldn't get IV access after a couple attempts by the PHHP (prehospital health professional) - a doctor and PHRN - you all know what that is.

We always get a follow up report on bad cases from the medical director of the aircraft service. Patient was placed on a new system they had for warming the blood in bypass. With in two hours, the patient was conscious, and by the next day, the patient was talking and in good condition. There was significant frost bite, and several toes had to be amputated. However, the patient developed multiple organ system failure, and died from kidney failure about a month later. But the important part was, IMO, the patient got some lucid moments to spend with the patients family, and got to say goodbye. So, there was closure.

[Lotus]

Holy crap....thats crazy o.o' I'm glad they had time to spend together at the end.

[Chief1C]

The patient initially didn't have much going in their favor. As you warm a severely hypothermic patient, without vascular access, you're setting the stage for cardiac arrest. You can manage that, if appropriately equipped. But it all depends on the patient, the degree of exposure, medical conditions and general health. Despite the patient being elderly, and diabetic - which is bad in the recovery of the extremities, as far as pre-existing poor perfusion. The patient was in relatively good health. Without intervention, the patient would have succumbed silently; with it, the patient came close to dying anyway. The potential for vasodialation, which causes hypotension, poor perfusion, arrythmia, arrest; was there.. In fact, the hear rate dropped off relatively fast, with the occasional PVC. However, the patient never arrested, I don't know what meds were pushed into the IV line, but the HR did stabilize.