Updated ACLS Guidelines Emphasize
Out-of-Hospital Actions

Heidi Splete

November 04, 2021

The guidelines for advanced cardiac life support (ACLS) underwent a comprehensive 5-year update in 2020, but focused updates for 2021 highlight the chain of survival, both in- and out-of-hospital, said Cameron Berg, MD, an emergency medicine physician in Minneapolis, Minnesota, in a virtual presentation at the American College of Emergency Physicians (ACEP) 2021 Scientific Assembly.

The ACLS guidelines refer to publications from the American College of Cardiology and the American Heart Association pertaining to cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC), said Berg. Comprehensive updates to the ACLS are issued every 5 years, and the 2020 publication is intended to be the primary guideline through 2025, he said.

The full ACLS guidelines include information on basic and advanced pediatric and neonatal life support, but Berg highlighted several of this year's updates to the adult and basic life support, resuscitation science, and systems of care.

When reviewing evidence-based guidelines, it is up to the clinician to determine the best potential applicability of the topics included, Berg said.

"I would encourage you to remember the chains of survival, which have been part of the guidelines for the last two cycles," he said.

The adult in-hospital cardiac arrest (IHCA) chain of survival includes early recognition and prevention, activation of emergency response, high-quality CPR, defibrillation, postcardiac arrest care, and recovery.

The out-of-hospital cardiac arrest (OHCA) chain of survival starts with activation of emergency response, followed by high-quality CPR.

The updates for 2021 for OHCA in particular emphasize chest compressions in cases of presumed cardiac arrest, Berg said.

Out-of-Hospital Actions

"Despite recent gains, less than 40% of adults receive layperson-initiated CPR, and fewer than 12% have an AED applied before EMS arrival," said Berg. "This is an important takeaway. Bystander CPR is imperative if we are going to achieve good population outcomes."

The OHCA updates are all about chest compression, he said. Data support the use of hands-only CPR, and training for law enforcement, firefighters, other first responders, and laypersons are "imperative," said Berg. "Teach everyone in your life to do high-quality chest compressions."

Without early recognition and prevention on the out-of-hospital side, there will be many fewer patients for emergency physicians to manage in-hospital. "Seconds and minutes count," he added.

Berg briefly touched on the use of naloxone (Narcan), recommended for basic life support in cases of opioid overdose when the patient has a pulse. Lay responders such as law enforcement and firefighters can administer naloxone and save lives, he said.

The guidelines for pre-hospital ACLS include algorithms for basic life support termination of resuscitation, said Berg. If the cardiac arrest is not witnessed and bystander CPR has not occurred, with no return of spontaneous circulation and no shock delivered before transport "the odds of survival are so low, it is appropriate to consider termination in the field," Berg added. These basic algorithms have been published as guidelines for BLS and ACLS, he said.

However, if there is a shockable rhythm, the guidelines call for shock and drug therapy, and continued resuscitation and transport, he added.

Advanced Airway Advice

The recommendations for advanced airways are that any approach is permissible, said Berg, therefore, "use the device you are comfortable with and trained in," as current research shows no significant differences between bag mask valves and endotracheal intubation, he said.

Supraglottic airways are another option, but the bottom line is to minimize the time spent on an advanced airway, so reliable training is paramount, Berg noted.

Routine drugs are not recommended for ACLS, said Berg. Epinephrine at a fixed dose can be used early, but it is most beneficial in patients with unshockable rhythms, he said. The guidelines recommend confirmation of airways with the amount of carbon dioxide in exhaled air (ETCO2), ideally via waveform, and checking for return of spontaneous circulation (ROSC) in cases of a rapid increase in ETCO2, noted Berg. An ETCO2 measure below 10 mm Hg after 20 minutes of CPR is highly correlated with negative outcomes, he added.

Extracorporeal Life Support

The ACLS guidelines have specifically identified extracorporeal life support (ECLS) for consideration in certain circumstances, said Berg. First, a system must be available, he said. Also, ECLS "should be used to treat a suspected reversible cause," in a patient with good baseline functional status and a short duration of prehospital CPR, given the high cost and complexity of the intervention, he emphasized.

ECLS data have mainly been limited to observational studies in hospital settings, Berg noted. The evidence is insufficient to recommend routine use, but it may be considered for the right population, such as patients with refractory ventricular tachycardia or ventricular fibrillation. The best outcomes with ECLS occur in cases when cannulation is administered in the first 15 minutes, and most protocols call for coronary angiography, Berg said.

An update to the guidelines for post-arrest management includes the use of coronary angiography if ST elevation is present, Berg added. Post-arrest guidance also calls for targeted temperature management for comatose OHCA survivors, he said.

Berg concluded by sharing some ACLS pearls "outside of the guidelines" that he has found helpful in clinical practice, notably precharging defibrillators, using ultrasound to confirm PEA (pulseless electrical activity), and "being more nuanced" in the use of epinephrine, with doses based on blood pressure.

Looking ahead, more research is underway on intra-arrest vasodilator therapy, he noted.

Berg has disclosed no relevant financial relationships.

American College of Emergency Physicians (ACEP) 2021 Scientific Assembly: Dr Berg's Presentation. Delivered October 25, 2021.

Heidi Splete is a freelance medical journalist with 20 years of experience.

For more news, follow Medscape on Facebook, Twitter, Instagram, YouTube, and LinkedIn


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.