Koolatron

iceman

Every morning I come to work, I switch the medic gear out of the night paramedic’s ambulance and put it into my assigned ambulance. Life Pack 12 monitor, Stat-Pack house bag, pedi box, spare drug case and two narc kits. Lately, more items have been added to the switch list – a digital camera, a laptop Toughbook computer, a battery powered hydraulic stretcher, and our cooler.

Koolatron

The cooler or Koolatron isn’t very heavy, but it is quite bulky, and I have to wedge it into the space between the front and the back of the ambulance where it partially blocks the door to the narcotics cabinet. The Koolatron’s power chord connects to the cigarette lighter in the dash. If the power chord detaches in the middle, you have to be careful to reattach it with the blue dot facing the arrow and not the red dot. Initially unknown to us, the Koolatron also has a Heatatron feature. We opened the Koolatron one day to find steam rising out of it. Not good for the contents, which fortunately we had no need for on that particular day.

We use the Koolarton occasionally to keep our groceries cool. My daughter’s grandmother is Jamaican and I often buy five pound bags of oxtail or goat meat from a local grocer to bring home for her to cook. The rumor that we use the cooler to keep beer in is simply not true. No EMS TV series will be based on our zany or depraved escapades as we are all too old or boring or busy doing the real work of EMS to think of such activity.

The primary purpose of the Koolatron is to carry two 1000 cc chilled bags of Normal Saline, two 10 cc drip sets, four commercial ice packs ready to be popped, and a piece of paper detailing all the steps in our new Induced Hypothermia protocol. We really could get by with a smaller Koolatron, but hey, this one was on sale for $79.

CPR in Progress

On a recent afternoon, we are called for difficulty breathing at one of the homes up in the hills at the far end of town. We’re updated by the EMD dispatcher that the patient is unconscious and the caller is uncertain if he is breathing. We hear the police arrive on scene and then the tell-tale message is relayed, “CPR in progress.”

It has been a couple months since I’ve done a cardiac arrest. After we arrive on scene, I find myself standing over the patient, a large man laying by the open car door having his chest pounded upon by the police officer, wondering what I should do first. It is probably only a five second delay, but it seems like I am standing there for ten minutes.

I’m trying to decide whether I should attach him to the monitor or break open my intubation kit. And whether I should get him on a board and get him on the stretcher and into the ambulance where I can start working him or work him right here where he was pulled out of the car.

Since he is already on the officers defib and it has announced “no shock advised,” I see no immediate need to slap him on mine. So I decide, and I think correctly, to intubate and work him right here.

You can say I am doing this all to give the patient the best chance to live, but the truth is I have been doing this long enough to know his odds of living are so long that our response is more faithfully carrying out a role than actually being life-savers. What I mean by that is I have no expectations for a successful resuscitation. The man looks to be in his eighties. His head is blue (thus my decision to intubate instead of continuing to bag). The 911 call came in 15 minutes before our arrival and it was a good seven or eight minutes before the police officer got there and found him not breathing. The man’s elderly wife sits on the front steps of their house, watching us silently. She doesn’t seem to have an appreciation for the direness of his situation.

I drop the tube in and am surprised to see an initial ETCO2 of 50, which soon drops to the 20s as we begin to ventilate. My partner has attached my monitor now and when we stop CPR briefly, the rhythm is flat line. I have the IV kit out, and am pleased to see some big blue veins in his hand, so with no need to stop CPR again to roll him to get his snow jacket off (it is unzipped but he is a big man and both arms are still in the jacket), I pop a twenty in his hand and slam in a quick epi and atropine.

ROSC (Return of Spontaneous Circulation)

And then just like that the ETC02 jumps back to the 50’s. “Check for pulses,” I say. My partner feels the man’s neck and announces, “I got one. Nice and strong.”

Wow. I always think that when I get pulses back. Not a big tremendous wow, but a small appreciative wow.

No time to rest however. We get him on a board and keeping a close eye on the ETCO2, get him up on the stretcher and into the back of the ambulance. We roll him enough to get his left arm out of this snow jacket where we take a blood pressure and find it to be 110/50. I get my scissors out to cut the jacket off his right arm, but right before I cut, I sense that the jacket is perhaps down, and cutting it may not be a great idea, so I leave the jacket on the arm and the coat under him.

Induced Hypothermia

It has already occurred to me that I am going to get to use the induced hypothermia protocol for the first time. I am lucky that one of the officers is also a paramedic, so I enlist him to accompany us to the hospital. I work one paramedic all the time and can handle a code by myself, but having another medic there is great. He manages the airway and keeps an eye on the monitor, where we have a nice narrow complex rhythm going. I pop in another IV and spike the two bags of chilled saline and get them running. We have a rider with us today and she breaks open the ice packs and stuffs them in the man’s arm pits and groin. I fish the protocol out of the cooler to see what else I am supposed to do and find it all soaking wet and stuck together, but the print is still legible.

My question concerns how much Versed to give the patient. We use the Versed to keep the patient from shivering. It says 2-5 mg slow IV push if the blood pressure is over 90 mm HG. I get the controlled substance kit out, which is hard because the Koolatron partially blocks the door, but after giving the cooler a good shove and reaching in I am able to get the kit out. I recheck the patient’s blood pressure. 65/30. Scotch the Versed. I get out the premixed dopamine, which I attach piggybacked to one of the lines.

The patient has pinked up quite nicely and the officer says he can feel the patient trying to breathe on his own. I call the hospital and tell them we are bring in a ROSC with the induced hypothermia protocol running. I try to get a 12-lead, but get way too much artifact to be able to make anything out of it.

My next pressure is 94/60, but since we are just now pulling into the ED, I hold off on the Versed.

In the code room, an anxious group of nurses, techs and residents descend on the patient, and I do my best to protect the tube and lines when the patient is yanked onto the hospital’s bed. I repeatedly say “this is the hypothermia protocol.”

Feathers

I turn briefly turn my back on patient to address the attending who has just walked into the room. When I turn back I see snapping scissors, the air filled with feathers, the patient naked, and the four ice packs thrown on the floor instead of packed in the groin and arm pits.

There is much confusion as this is a new protocol. It seems some of the staff are under the impression I have brought in a hypothermic patient who needs rewarming. I have to explain, I am instead trying to cool the patient. The attending understands this and orders new ice packs applied and the warmed blankets and arriving Bear Hugger not attached. (Although eventually the Bear Hugger will be used to try to keep the patient at just the right moderate cooled temperature).

The man, who has an extensive medical history, gets admitted to the Intensive Care Unit (ICU) where he lives for a week. I eventually see his name in the morning paper on the obits page.

It would have been nice to report he walked out of the hospital on his own steam and that he and his wife brought us a huge hot apple cobbler pie, but it is what it is. There are few survivors of cardiac arrest, particularly at such an advanced age with such an extended medical history and being without CPR for so long.

But that may change. There is a great deal of promise in this induced hypothermia, which is making its way into EMS systems across the country, based on quite promising evidence from clinical field trials and experiences of those systems who have tried it.

Some History

Hippocrates advocated packing wounded soldiers in snow and ice. Napoleonic surgeon Baron Dominque Larrey observed that wounded officers, who were kept closer to the fire, died more frequently than the infantrymen who slept in the snow. By 2003, based on recent research, the American Heart Association endorsed therapeutic hypothermia post cardiac arrest for the first time.

The Study

The landmark study, Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. was published in 2002 in the New England Journal of Medicine. Researchers studied patients resuscitated from v-fib arrests. Patients were randomly assigned hypothermia or not. The outcomes were 1) favorable neurological outcome within 6 months, 2) mortality within six months. There were 136 patients in hypothermia group, 137 patients in normothermia group.

These are the results:

Favorable Neurological outcome at 6 months:
Hypothermia group – 75 patients
Normothermic group – 54 patients

Mortality at 6 months:
Hypothermia group – 41 percent
Normothermic group – 55 percent

The study’s conclusion: “In patients who have been successfully resuscitated after cardiac arrest due to ventricular fibrillation, therapeutic mild hypothermia increased the rate of a favorable neurologic outcome and reduced mortality.”

Physiology

The idea behind cooling seems to be that cooling functions as a neuroprotectant that helps maintain cell membrane stability, limits intracranial pressure, limits inflammatory response and keeps out destructive free radicals that can be unleashed when the brain is reperfused following injury.

Regional Guidelines

Our regional guidelines call for inducing hypothermia in any ROSC patient after cardiac arrest not related to trauma or hemmorage provided the patient is over 18, not obviously pregnant, and with no signs of hypothermia. The patient has to be intubated (An LMA or combitube will suffice, and the patient has to have no purposeful response to pain.

Hypothermia is induced by exposing the patient; applying ice packs to Axilla & Groin, giving Midazolam 2-5 mg (0.1 mg/kg) if systolic pressure is over 90 mmHG Slow IV Push, and a cold Saline Bolus 30mL/kg to max of 2 liters. If the SBP is below 90mmHg, we can administer Dopamine 5-20mcg/kg/min IV titrated to SBP of 90mmHg.

Our protocols include the following Pearls:
If no advanced airway in place, do NOT INDUCE HYPOTHERMIA

AT ANY TIME Loss of Spontaneous Circulation: Discontinue cooling and go to appropriate protocol

Monitor ETCO2 Target 40 mmHg DO NOT HYPERVENTILATE

During Neuro Exam, look for purposeful movements.

Cold Saline should be chilled to about 4 C. (39.2 F)

Blood Pressure of less than 90 mmHg, is not a contraindication for the administration of hypothermia.

When exposing patient for purpose of cooling undergarments may remain in place. Be mindful of your environment and take steps to preserve the patients modesty.

Do not delay transport for the purpose of cooling.

Perform a 12-lead EKG with ROSC if time and staffing permit,

Reassess airway frequently and with every patient move.

Patients develop metabolic alkalosis with cooling. Do not hyperventilate.

Links:

Here are some links JEMS has about hypothermic cooling:

JEMS Links

2 Comments

  • brendan says:

    We can’t even get all our agencies onboard with ETCO02. Cooling is probably another decade off for us, and by that time it’ll be something else anyways.

    I hate this place sometimes.

  • Jack says:

    This is all very interesting stuff. At least two of our major services up here in my neck of Canada have volunteered to test some of the new therapeutic hypothermia protocol and it looks like many of the province’s hospitals are jumping on board as well. Should be interesting to see just how widely implemented it becomes. Sounds promising, to be sure!

    PS – The shears vs. down jacket faceoff is always a laugh 😛

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