What is Agonal breathing?

From the Guidelines

Agonal breathing is a life-threatening condition that requires immediate medical attention, and if you observe someone with agonal breathing, you should call emergency services immediately and begin CPR if trained. Agonal breathing is characterized by slow, irregular gasping respirations that are ineffective for ventilation, as described in the 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. Key signs of agonal breathing include:

• Gasping, snorting, or labored breathing
• Long pauses between breaths
• Open mouth and abnormal jaw movements If you encounter someone with agonal breathing, it is essential to:

1. Call for emergency help immediately
2. Begin CPR if trained
3. Use an AED (automated external defibrillator) if available
4. Continue CPR until emergency responders arrive Agonal breathing occurs when the brain stem is still firing respiratory signals, but the body is no longer able to breathe effectively, and it is often mistaken for normal breathing, which can delay critical intervention 1. Recognizing agonal breathing and acting quickly can significantly improve the chances of survival in cardiac arrest situations. The presence of agonal breathing is common, reported as being present in up to 40% to 60% of victims of out-of-hospital cardiac arrest (OHCA), and the identification of abnormal breathing or agonal gasps is crucial in the recognition of cardiac arrest by emergency dispatchers 1.

From the Research

Definition and Characteristics of Agonal Breathing

• Agonal breathing, also known as agonal respirations, refers to abnormal breathing patterns that occur during cardiac arrest 2, 3.
• These breathing patterns originate from lower brainstem neurons as higher centers become increasingly hypoxic during cardiac arrest 2.
• Agonal respirations can produce clinically important ventilation, oxygenation, and circulation, as demonstrated in animal studies 2.
• In human studies, agonal respirations are apparent in 40% of persons suffering out-of-hospital cardiac arrest and are associated with witnessed events, ventricular fibrillation, and survival 2, 3.

Clinical Significance and Implications

• Agonal respirations pose a challenge to bystanders and emergency dispatchers, as they may be mistaken for normal breathing, leading to delayed recognition of cardiac arrest 3, 4.
• Teaching recognition of agonal breathing can improve the accuracy of diagnosing cardiac arrest and initiating CPR 4.
• The presence of agonal respiration has been associated with favorable neurological outcomes in patients with refractory cardiac arrest, particularly when maintained and treated with extracorporeal cardiopulmonary resuscitation (ECPR) 5.
• Agonal breathing, along with seizure-like activity, has been linked to favorable outcomes in patients with out-of-hospital cardiac arrest 6.

Incidence and Predictors

• The incidence of agonal respirations in cardiac arrest patients is estimated to be around 40-55% 2, 3.
• Agonal respirations are more common in witnessed cardiac arrests, ventricular fibrillation, and shockable rhythms 2, 3.
• Seizure-like activity, which can occur concomitantly with agonal breathing, is more common in patients with shockable initial rhythms, sudden cardiac arrest, and presumed cardiac etiology 6.