The American Heart Association recently released the new American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care 2020. These Guidelines represent the culmination of a rigorous evidence review process spanning multiple years.
In total, the AHA made 491 evidence-based recommendations across six resuscitation categories. While it might be tempting to believe strong evidence drives the recommendations, that is simply not the case. High-quality evidence from more than one randomized controlled trial accounted for only 1% of the recommendations [1]. The expert writing teams based more than half of their recommendations on limited evidence, with expert opinion forming the basis of an additional 17% of the recommendations [1]. This article will provide an overview of the major clinical, educational and system of care recommendations in the AHA CPR and ECC Guidelines 2020.
Adult basic and advanced life support
Chest compression quality. While not altering current recommendations for compression depth and rate in adult patients, the AHA CPR Guidelines 2020 reaffirm the importance of chest compression quality in achieving improved survival measures. The AHA continues to make a strong recommendation for chest compressions of at least two inches but not more than 2.4 inches in the adult patient, based on moderate quality evidence. In contrast, there is a moderate-strength for compression rates of 100-120 compressions per minute, based on moderate quality evidence.
Double sequential defibrillation. Although many EMS agencies around the country include double sequential defibrillation in their treatment protocols, previous AHA guidelines were silent on the subject [2]. Current published evidence on the usefulness of this strategy for shock-refractory episodes of ventricular fibrillation or pulseless ventricular tachycardia remains limited and weak. Because of this level and quality of evidence, the strongest recommendation the AHA can make in 2020 is that resuscitation team mays consider the strategy.
Intraosseous access. Another interesting recommendation involves the manner in which resuscitation teams gain access to the vascular space for medication administration. Historically, venous cannulation was the primary access strategy. Recently however, many EMS agencies began moving away from initial IV attempts during resuscitation in favor of intraosseous access. Unfortunately, a rigorous review of the evidence questions the efficacy of the IO route when compared to the IV route. Based on moderate quality evidence not involving a randomized trial, the AHA believes it is reasonable for resuscitation teams to first attempt IV access. When IV attempts are unsuccessful or access is not feasible, there is a weaker recommendation for the teams to consider establishing an IO.
The use of epinephrine in cardiac arrest. Last year, a focused update on the use of epinephrine in cardiac arrest concluded that resuscitation teams should continue to administer epinephrine for the treatment of cardiac arrest in adult patients at 3-5 minute intervals for the duration of the resuscitation attempt [3]. The AHA CPR Guidelines 2020 strongly reaffirm that position, based on moderate quality evidence. With respect to timing, the AHA Guidelines 2015 made a weak recommendation that resuscitation teams consider giving epinephrine as soon as feasible when the patient presents with a non-shockable rhythm [2]. The AHA CPR Guidelines 2020 now strengthen that recommendation with moderate quality evidence based on limited data. The AHA Guidelines 2015 made no recommendation on when resuscitation teams should administer epinephrine to patients with shockable rhythms. The 2019 AHA focused update recommended epinephrine administration for shockable rhythms after initial defibrillation attempts have failed [3]. The AHA CPR Guidelines 2020 reaffirm that position as a weak recommendation based on limited data. Changes to the algorithm now depict epinephrine administration as appropriate after the second defibrillation attempt for shock refractory rhythms.
Pediatric basic and advanced life support
Chest compression rate and depth. As with the adult patient, the AHA CPR Guidelines 2020 do not alter previous compression depth and rate recommendations for pediatric patients. The AHA makes a moderate-strength recommendation for chest compressions depths of one-third the anterior-posterior diameter of the chest for infants and children, based on limited data. Limited data also supported the AHA CPR Guidelines 2020 reaffirmation of the moderate-strength recommendation for compression rates of 100-120 compressions per minute.
Advanced airway management. One recommendation specifically addressed to prehospital care involves the decision to use an advanced airway during pediatric resuscitation. Last year, the AHA addressed whether EMS providers should provide bag-mask ventilation with or without an advanced airway [4]. At that time, the AHA stated the strength and quality of the evidence prohibited a recommendation for or against the use of an advanced airway during the pediatric resuscitation attempt. They also could not recommend one type of advanced airway device as clearly superior to another device. Based on limited data, the AHA CPR Guidelines 2020 reviewers conclude that rates of survival to hospital discharge and survival with good neurologic outcome are similar between pediatric patients treated with BVM ventilation and those treated with endotracheal tube ventilation. The AHA makes a moderate-strength recommendation for the use of bag-mask ventilation over endotracheal tube ventilation.
Ventilation rates. One of the most interesting recommendations related to pediatric resuscitation involves updates to assisted ventilation rates. For years, the AHA warned about the very real dangers of overventilation during cardiac arrest. Increasing assisted ventilation rates during CPR raises intrathoracic pressure, which reduces venous return to the heart. However, results from a large multi-center observational trial found in-hospital resuscitation teams often provide ventilation rates in excess of recommended rates [5]. More importantly, researchers found an association between faster ventilation rates and improved survival to hospital discharge for infants with endotracheal intubation. Thus, based on limited data, the AHA CPR Guidelines 2020 make a weak recommendation for providing one breath every 2-3 seconds (20-30 breaths/min) for infants and children with an advanced airway.
The use of epinephrine in cardiac arrest. No high-quality evidence drives intra-resuscitation drug administration recommendations for infants and children who suffer cardiac arrest. The basis for all 2020 AHA recommendations is limited data. The AHA CPR Guidelines 2020 reaffirm the previous moderate-strength recommendation for the use of epinephrine during pediatric resuscitation attempts. The AHA CPR Guidelines 2020 also make a moderate-strength recommendation for resuscitation teams to administer the first dose of epinephrine within the five minutes after beginning chest compressions. This recommendation should prompt EMS systems to evaluate their current pediatric resuscitation practices for ways to meet this recommendation. Resuscitation teams should continue to administer epinephrine at 3-5 minute intervals. Finally, the AHA CPR Guidelines 2020 reaffirm a previous moderate-strength recommendation for the use of either amiodarone or lidocaine for shock-refractory V-fib/pVT.
This article examines only a glimpse of the recommendations related to major clinical topics associated with resuscitation following cardiac arrest. There are many other clinical recommendations that do not apply to the prehospital environment, although they do contribute to overall survivability. In addition, over the past decade or so, researchers have directed considerable resources into using research to guide resuscitation education practices as well as driving system of care changes to help optimize survival. Over the next few weeks, we will explore all of these recommendations in more detail.
References
- Merchant, RM; Topjian, AA; Panchal, AR; Cheng, A; et al. (2020). Part 1: Executive summary: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 142(16 Suppl 2), S337-S357. doi:10.1161/CIR.0000000000000918
- Link, MS; Berkow, LC; Kudenchuk, PJ; Halperin, HR; et al. (2015). Part 7: Adult advanced cardiovascular life support: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 132(18 Suppl 2), S444-S464. doi:10.1161/CIR.0000000000000261
- Panchal, AR; Berg, KM; Hirsch, KG; Kudenchuk, PJ; et al. (2019). 2019 American Heart Association focused update on advanced cardiovascular life support: Use of advanced airways, vasopressors, and extracorporeal cardiopulmonary resuscitation during cardiac arrest: An update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 140(24), e881-e894. doi:10.1161/CIR.0000000000000732
- Duff, JP; Topjian, AA; Berg, MD; Chan, M; et al. (2019). 2019 American Heart Association focused update on pediatric advanced life support: An update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 140(24), e904-e914. doi:10.1161/CIR.0000000000000731
- Sutton, RM; Reeder, RW; Landis, WP; Meert, KL; et al. (2019). Ventilation rates and pediatric in-hospital cardiac arrest survival outcomes. Critical Care Medicine, 47(11), 1627–1636. doi:10.1097/CCM.0000000000003898
The author has no financial interest, arrangement, or direct affiliation with any corporation that has a direct interest in the subject matter of this presentation, including manufacturer(s) of any products or provider(s) of services mentioned.
