AHA Updates its Cardiac Arrest Guidelines

What to know from the new AHA cardiac arrest management guidelines

In December 2023, the American Heart Association published a “focused update” to its landmark guidelines for the management of cardiac arrest. PulmCCM is not affiliated with the American Heart Association.

Read the document for all the details (it’s not long). Here’s PulmCCM’s take on the new changes.

Targeted temperature management is out; fever prevention is in.

Cooling patients to targets below 37.5°C is no longer recommended after cardiac arrest (nor is it discouraged; maintaining temperature 32°C to 37.5°C was advised).

There should be an active approach to fever prevention (e.g., automated external cooling system) for all arrest patients (with any presenting rhythm, occurring in- or out-of-hospital) maintained for at least 24 hours; longer periods of fever prevention (which AHA now calls “temperature control”) for persistently comatose patients are also considered reasonable.

Patients presenting with hypothermia should not be warmed too quickly (allowing their temperature to increase by <0.5°C/hour).

We went into more detail on this last week:

Another very large trial (ICECAP) is in process, testing cooling to 33°C for various durations up to 72 hours—but with no normothermia/fever prevention control arm. Results are expected in 2025.

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Epinephrine remains the drug of choice during CPR

Epinephrine remains the first-line therapy for cardiac arrest due to non-shockable rhythms (i.e., PEA and asystole). No new evidence arose to alter the usual schedule of administering 1 mg epinephrine as quickly as possible, then every 3 to 5 minutes while CPR is ongoing.

For shockable rhythms, no evidence emerged to change the usual practice of delaying epinephrine until CPR with multiple attempts at defibrillation (e.g., three shocks with 2 minutes CPR in between) have been performed.

Vasopressin, with or without methylprednisolone, was weakly endorsed as an optional adjunct to epinephrine, although without proven benefits. A randomized trial showed improvement in ROSC with 20 IU vasopressin + 40 mg methylprednisolone after the first dose of epinephrine for in-hospital arrests, without any survival or neurologic benefit seen. Systematic reviews could not verify a benefit from vasopressin.

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Don’t routinely give bicarbonate, magnesium, or calcium

There is no known benefit to administering bicarbonate, calcium, or magnesium for cardiac arrests not known to have a specific indication for these drugs (e.g. bicarbonate and calcium for known hyperkalemia; magnesium for torsades de pointes). Giving bicarbonate, magnesium, or calcium during undifferentiated cardiac arrest was weakly advised against.

Any benefit of steroids during cardiac arrest remains unclear and is under further investigation.

Amiodarone and/or lidocaine continue to be endorsed (weakly) as second-line therapies for shockable rhythms, should multiple defibrillation efforts fail.

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Emergent left heart catheterization post-arrest?

Patients with cardiac arrest and ST-segment elevation myocardial infarction should undergo emergent left heart catheterization with percutaneous coronary intervention (PCI)—even if deeply comatose, according to the guideline authors.

For stable patients post-arrest, emergent left heart cath was advised against.

Consideration for emergent cath was urged for hemodynamically unstable patients without ST-elevations but with potential ischemic cardiac disease as a major contributor (e.g., electrical instability, high troponin levels exceeding that predicted from “strain,” new wall motion abnormalities on echo, etc).

Due to the absence of guiding evidence, the recommendations leave considerable leeway to individual cardiologist decision-making.

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EEG Advised, to Rule Out Nonconvulsive Seizures

Nonconvulsive seizures are occasionally present in comatose patients after cardiac arrest, undetectable without testing. No strong evidence exists to suggest that detecting and treating nonconvulsive seizures improves neurologic outcomes after arrest, but there’s a compelling pathophysiologic rationale to prevent further brain injury.

“Prompt” electroencephalogram (EEG) was advised strongly for all cardiac arrest survivors not following commands. Repeating EEGs periodically (or continuously) was weakly recommended for persistently comatose patients. There is no evidence to suggest benefit of continuous EEG monitoring.

Abnormal EEGs suggestive of ictal activity (even without meeting formal criteria for seizure identification) are sufficient to warrant a period of treatment with anti-epileptic therapy. Typical anti-epileptic therapies were advised, avoiding sedating agents that interfere with accurate neurologic exams and prognostication.

Seizure prophylaxis was advised against, as there is no evidence for its efficacy.

Myoclonic jerks occurring without evidence of cortical seizures on EEG may not themselves require treatment with anti-epileptics.

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ECMO Centers, Consider ECPR For Patients Not Achieving ROSC

Two recent randomized trials (ARREST and Hyperinvasive) suggested a possible benefit of veno-arterial extracorporeal membrane oxygenation initiated on patients failing usual resuscitation protocols with CPR, shocks, epinephrine, etc. (ECMO used as CPR is referred to as ECPR.)

ECPR was therefore weakly recommended as an option at centers highly experienced in ECMO.

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Organ Donation Consideration Advised

The guidelines also recommended consideration of organ donation in post-cardiac arrest patients meeting criteria for brain death (now called death by neurological criteria) or whose families are considering withdrawal of life support.

While an increase in the supply of organs for transplant is a societal good (all else being held equal), it’s a controversial inclusion in guidelines centered on optimizing care for the cardiac arrest patient. Consideration of the value of a comatose patient’s organs to potential donor recipients introduces an ethical conflict of interest for the treating physician.

In accordance with the fraught ethical and emotional factors surrounding organ donation, this section is the tersest, least explicated section of the document. Clinicians are advised to consider organ donation in appropriate patients, while “following local legal and regulatory requirements.” Treating teams may be prohibited from discussing organ donation with a patient’s family until after the decision to withdraw life support has been made, or brain death declared. Many hospitals have a policy of proactively contacting an organ procurement agency for all comatose post-cardiac arrest patients; an agency representative then initiates contact with arrest patients’ families independently of the treating team.