The evidence supporting AHA guidelines on adult cardiopulmonary resuscitation (CPR)

Background Guidelines for the management of cardiac arrest play a crucial role in guiding clinical decisions and care. We examined the strength and quality of evidence underlying these recommendations in order to elucidate strengths and gaps in knowledge. Methods Using the 2020 American Heart Association (AHA) Guidelines for Adult CPR, we subdivided all recommendations into advanced life support (ALS), basic life support (BLS), and recovery after cardiac arrest, as well as a more granular categorization by topic (i.e. the intervention or evaluation recommended). The Class of Recommendation (COR) and Level of Evidence (LOE) for each were reviewed. Results We noted 254 recommendations, of which 181 were ALS, 69 were BLS, and 4 were recovery after resuscitation. In total, only 2 (0.8%) had the most robust evidence (LOE A), while 23% were at LOE B-NR(Non-Randomized), 15% at LOE B-R (Randomized), 50% at LOE C-LD (Limited Data), and 12% relied on expert opinion LOE C-EO (Expert Opinion). Despite the strength of ALS recommendations (Class 1, 2a, or 2b), none had LOE A. In BLS, no recommendations were supported by LOE A. For BLS, 74% of recommendations had LOE C (C-LD or C-EO). The evidence for specific BLS topics, such as airway management, was notably low. Among ALS topics, neurological prognostication had relatively stronger evidence. Overall, 26.1% of BLS recommendations had LOE A or B, versus 43.1% for ALS recommendations. Conclusions There is a strong discrepancy between the strength of recommendation and the underlying evidence in cardiac arrest guidelines. The findings underscore a pressing need for more rigorous research, particularly randomized trials. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial The study was conducted as a meta-analysis on existing guidelines and published data. As no clinical trials or prospective interventions were conducted, there was no requirement for study registration in a clinical trial registry as per registration guidelines ### Funding Statement No external funding was received for the work presented in this manuscript. The authors and their affiliated institutions have not received any payment or services from a third party for any aspect of the submitted work. This research was conducted without the support of external grants or financial contributions ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: No specific IRB or oversight body approval or exemption is required for the described research. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes To conduct this study, we utilized the American Heart Association (AHA) Guidelines for Adult CPR from 2020. All recommendations pertaining to advanced life support (ALS), basic life support (BLS), and recovery after cardiac arrest were reviewed according to the guidelines, and the classifications (Class of Recommendation, COR) and levels of evidence (Level of Evidence, LOE) for each recommendation were documented. This study is solely based on the analysis of and references to the publicly available 2020 AHA guidelines and does not involve separately collected data.