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The Role of Bystander-initiated Basic Life Support in Sports-related Sudden Cardiac Arrest: A Systematic Review

Background: Sudden cardiac arrest is the leading medical cause of death amongst athletes and a common cause of death during exercise. The provision of cardiopulmonary resuscitation (CPR) and automatic external defibrillator (AED) use by bystanders can greatly improve survival outcomes in sudden cardiac arrest. However, the effectiveness of these interventions within exertional settings requires further investigation. 
Objective: To evaluate the role of bystander-initiated CPR and AED use on survival outcomes amongst sports-related sudden cardiac arrest (SrSCA). 
Methods: Several databases and grey literature sources were queried from inception until November 2020 using a comprehensive search strategy. Abstract screening, full-text review, and data extraction of eligible studies were conducted independently by two reviewers. SrSCA was defined as a cardiac arrest which occurred during (or within 1-hour of) physical activity, sport, or exercise. Bystander CPR and AED rates, as well as appropriate survival outcomes, were extracted from each study, and overall summary measures were calculated. 
Results: A total of 2,850 unique records were identified, with 176 articles selected for full-text review, of which 32 studies were included in this review. The median rate of bystander CPR and AED use was 75% and 24%, respectively. Survival to hospital discharge ranged from 11%-93%, with a median rate of 33%. 
Conclusions: Majority of SrSCAs received bystander CPR and achieved a high rate of survival to hospital discharge, yet AED use was low. These findings encourage layperson education in basic life support, the availability of AEDs in athletic facilities, and emergency action plans to ensure timely resuscitation.