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Accidental Hypothermia and Cardiac Arrest

The management of the hypothermic patient is dictated by the stage of hypothermia. Patients in stage I are still able to generate heat by shivering and thus require only passive rewarming measures: removing cold and wet clothes, wrapping in warm blankets, providing warm sweetened fluids by mouth. Hypothermia stages II and III patients require active external rewarming (forced air rewarming, radiant heat and application of heat packs) as well as minimally invasive rewarming techniques (IV fluids warmed to 40°C). Hypothermia stage III may also require airway management based on neurological and respiratory status as well as extracorporeal membrane oxygenation (ECMO) if there are persistent ventricular…

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  Hypothermia

Hypothermia is defined as any core temperature < 35 degrees Celsius.

 Hypothermia: Keeping your cool when it gets cold

We seek to review the scope and principles of hypothermia, how to appropriately measure temperature, discuss rewarming methods and review the current existing guidelines and evidence around hypothermia management.

 Hypothermic Cardiac Arrest

On the less invasive side, warmed IV fluids at 40°C can be infused. Warmed humidified oxygen can be administered via nonrebreather or ET tube in intubated patients. Bladder and gastric lavage are the next measures you can take. They involve placing a Foley or NG/OG tube and instilling 300-500cc of warmed fluids, allowing it to swell for 5-10 minutes, and then draining and replacing the fluid.

 Management of Hypothermia from Wilderness to the ED

In sicker, colder patients, or those with serious dysrhythmia, active core rewarming (ACR) should be pursued. ACR methods vary greatly in degree of invasiveness and, although many are used concomitantly, care should progress from least to most invasive, based on the patient's condition. The two most commonly used and least invasive maneuvers are heated humidified air inhalation and heated IV fluids.

 Until they are warm and dead: Severe Accidental Hypothermia

Do not need to worry much until temp hits ~32° C

 What Leonardo DiCaprio can teach us about Hypothermia

Those with mild hypothermia require only passive external rewarming, provided their body is shivering. Passive external rewarming simply means to discard the patient’s wet clothing and apply an insulating cover over the body.

Articles of Interest

Accidental Hypothermia

IV fluids should be warmed to 40°C. They do little to warm the patient but room temperature fluids can lead to further heat loss.

Accidental Hypothermia

Accidental hypothermia has produced many cases of intact survival even after prolonged cardiac arrest, but it is also often fatal. In recent years, alterations in resuscitation care that sometimes confused or discouraged resuscitation teams have largely been supplanted by an emphasis on safe, rapid, effective rewarming. Rewarming decisions and even the simple recognition of hypothermia remain challenging. This review seeks to update and demystify some of these challenges.

Accidental Hypothermia and Cardiac Arrest: Physiology, Protocol Deviations, and ECMO

Forced-air rewarming is the most commonly available method and has the least potential for complication, providing up to 1oC/hour.

Accidental Hypothermia – Clinical Pathway

Accidental hypothermia is defined as an unintentional drop in core body temperature below 35°C. It can present in any climate and in any season, as it is not always a result of environmental exposure; underlying illnesses or coexisting pathology can play important roles. Although there is some variability in clinical presentation, hypothermia produces a predictable pattern of physiologic re-sponses and clinical manifestations...

Air Care Series: Accidental Hypothermia

Hypothermia is classified on the basis of core temperature as mild (35°C-32°C), moderate (32°C-28°C), severe (28°C-24°C), or profound (<24°C). It can also be staged clinically using the Swiss staging system, particularly in settings where accurate measurement of core temperature is impractical or impossible.

Approach to Hypothermic Resuscitation

For those patients with a core temp >32°C with severe cardiac instability or in cardiac arrest, you should also consider alternative etiologies for their presentation rather than expect it solely caused by the hypothermia alone. Like you mention, if you are able to rewarm a cardiac arrest patient above this temperature and they remain in asystole, it is likely that irreversible damage has occurred and they are less likely to be able to be successfully resuscitated.

Baby It's Cold Outside: Hypothermia Management

Afterdrop is the additional drop in core body temperature once rewarming has started and has the highest incidence in patients with moderate to severe hypothermia. When rewarming begins, peripheral veins dilate and the cold blood with acidemia that has accumulated in the extremities returns to the heart. This can trigger ventricular fibrillation. To help avoid afterdrop, exclusive rewarming of the extremities should be avoided, and instead rewarming should focus on the torso.

Cardiac arrest in extreme hypothermia

Colloquially known as "freezing to death", cardiac arrest in extreme hypothermia is still a part of the critical care syllabus even in this severely overcooked country.

CRACKCast E140 – Accidental Hypothermia

There is a five level “Swiss staging” system that is used in some places (also supported by the International Commission for Mountain Emergency Medicine). This system is used by the International Commission of Alpine Rescue (ICAR). However, it’s not favored by all experts in the field of wilderness medicine because the clinical (especially the neurological) symptoms of hypothermia range widely from person to person. For example, a person could still be shivering and have a temperature below 32 deg.

EM@3AM: Hypothermia

Rewarm trunk before extremities due to possible “afterdrop” effect when the extremities vasodilate and release the cool blood back to core circulation.

Hypothermia & the ACLS algorithm

Let me point out what no-one seems able to come out and say: you have to do chest compressions for hours while rewarming the patient. The ER waitingt room will overflow into the parking lot. I am trying to come up with strategies to be more efficient with my next hypothermic.

Hypothermia at 18 Celsius in V Fib arrest: CPR, then ECMO rewarming, for 3 hours, then Defib with ROSC. Interpret the ECG.

On arrival, CPR was continued and core temperature was measured at 18° C (64.4° F). The patient was put on Extracorporeal Life Support in the ED.

Hypothermia for cardiac arrest

The HYPERION trial adds to the evidence that strict temperature control (and possibly mild hyperthermia) results in better outcomes for comatose cardiac arrest patients. It is the first trial to focus specifically on patients with non-shockable rhythms. It doesn’t provide us with definitive evidence, but until we see more data, it seems like all comatose cardiac arrest patients with ROSC should have their temperature controlled, and that the target should be between 33 and 36 degrees Celsius, not 37.

Management of accidental hypothermia: A narrative review

Extracorporeal life support has revolutionized rewarming of the hemodynamically unstable victim or patients suffering cardiac arrest, with survival rates of up to 100%. The new evidences indicate that the management of accidental hypothermia has evolved favorably, with substantial improvement of the final outcomes.

Paucis Verbis: Management of Accidental Hypothermia

So, in honor of all those bundled up and shivering, I wanted to review the management of accidental hypothermia. Tip: Avoid jostling the hypothermic patient too much because of myocardial irritability. Don’t send your patient into an arrhythmia.

Rescuing a Person with Hypothermia

Hypothermia is caused by prolonged exposure to abnormally low temperatures or prolonged exposure to dampness. It sets in when the internal body temperature drops to 95° (F) or lower.

Symptoms: Cardiac Arrest and Low Temperature

Hypothermia should not be a forgotten “H” in the ACLS guidelines for cardiac arrest. The case presented in this article highlights the reversibility of hypothermia and cardiac arrest.

The Dangerous Cold

Goal Is not normothermia...

The Quick and Dirty Guide to Hypothermia

Medications may be ineffective. Treatment primarily involves removing the patient from the cold environment, and initiating rewarming techniques.

Winter Is Still Coming! Reviewing Accidental Hypothermia

Patients suffering from accidental hypothermia should be managed aggressively. Those without cardiac instability can be managed with active, external warming and minimally invasive warming techniques. Patients with severe hypothermia, especially those in cardiac arrest, should be treated at a facility capable of extracorporeal rewarming. Given the advancements in rewarming techniques, the prognosis for patients suffering from hypothermia has improved.

Resources

5 Ways of Treating Hypothermia That Are Actually Dangerous Myths

The cold is one of humanity’s oldest adversaries, and over the millennia we’ve had plenty of time to create myths...

FOAMcast

Get a temperature, on all patients. This applies to patient’s “found down” as well as the chronic alcoholic who just seems really drunk... Warm the patient. Don’t call the patient dead until they’re warm and dead, which means their temp is above 30-32°C.

BC Emergency Medicine Network

Blood samples are warmed before analyzed – masks coagulopathy of HT.

Core EM

In urban settings hypothermia is often a reflection of underlying disease state, the rate of rewarming can reflect underlying pathology (i.e. inability of a sick patient to warm themselves); sepsis is an under-appreciated cause

EMCrit Project

Mild/moderate hypotension is common and should resolve with rewarming. Be cautious with vasopressors, given the risk of inducing arrhythmias. Vasodilation can occur with rewarming, so if blood pressures fall with rewarming this could be a better indication for vasopressors. Treating this empirically is extremely reasonable for hypothermic, shocky patients. Start dexamethasone (4-6 mg of IV) while awaiting the serum cortisol level. Dexamethasone is used because it doesn't interfere with the cortisol test.

Life in the Fastlane

NB. Afterdrop, a drop in core body temperature during rewarming may occur a consequence of peripheral vasodilation and release of cold peripheral blood to the body core. It is not usually significant.

NOLS Blog

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