Improving survival and outcome in those suffering an out-of-hospital cardiac arrest in the post-COVID-19 era

Cournoyer et al. [ ] assessed the association between bystander cardiopulmonary resuscitation (CPR), emergency medical service (EMS) response time, and out-of-hospital cardiac arrest (OHCA) patients’ outcomes. This pre-pandemic cohort study was derived from the Resuscitation Outcomes Consortium (ROC) OHCA registry (ROC Epistry) Version 1 and 2 (December 1st, 2005 to April 1st, 2010) and 3 (April 1st, 2011 to June 30th, 2015), which included cases assessed by EMS in the out-of-hospital setting who: a) underwent either EMS-performed chest compressions or had a shock delivered by a bystander-applied automated external defibrillator; or b) were found pulseless by EMS personnel, but did not receive treatment [ ]. Survival at hospital discharge was ascertained for all cases. They concluded that although bystander CPR is associated with an immediate increase in odds of survival and of good neurologic outcome for OHCA patients, it does not influence the negative association between longer EMS response time and survival and good neurologic outcome.

Using a Korean OHCA registry, Park and colleagues [ ] analyzed OHCA patients whose arrest was not witnessed by EMS providers between 2017 and 2021. Because lack of hospital and survival information in 2021, the 2021 data were used only to identify the expected trend. They found that survival to discharge was 5019 (8.2%) in pre-COVID-19 set and 1457 (6.6%) in post-COVID-19 set. The proportion of bystander CPR was 59.0% in the pre-COVID-19 set and 61.0% in the post-COVID-19 set. The median (interquartile range) response time was 7 (5–9) minutes in the pre-COVID-19 set and 8 (6–10) minutes in the post-COVID-19 set. Response time and on-scene management of EMS showed the highest impact on decreased survival. A similar trend was also expected in the 2021. They concluded that an effort to create a more rapid response system for OHCA patients could have priority for the recovery of survival outcomes in OHCA patients in the post-COVID-19 period. Further studies to recover survival outcomes of OHCA are warranted.

However, the reasons for the lack of influence of bystander CPR on survival with good outcomes when EMS response times are prolonged are likely because sternal compression was performed highly ineffectively in 50% of all OHCA cases, time to first compression was significantly delayed and no efforts were made to prevent asphyxial cardiac arrest and facilitate unobstructed gasping, which are critical for increasing survival with good neurological outcomes.

I first called attention to the fact that sternal compressions are performed in a highly ineffective manner in 50% of all cases [ ]. The 4-finger method of hand placement of the heel of the dominant bottom hand in contact with the sternum was proposed to avoid compression over the cranial side of the sternum and ensure maximally effective compression over the caudal half of the sternum adequately below the internipple line but safely above the xiphoid process (i.e., over the midpoint of the lower half of the sternum). I very recently proposed that in cases where a public access defibrillator is not readily available, eliminating instructions to remove clothing to bare the chest (see Fig. 1 ) and/or place the victim supine on the floor when the victim is found lying supine in bed, allows the 4-finger method of hand placement to be immediately applied with minimal delay and minimizes time to first compression [ ]. In addition, based on strong evidence in patients [ , ], use of head rotation (or turning the head maximally to one side) was also advocated as a hands-free method of airway control to prevent asphyxial cardiac arrest and facilitate unobstructed gasping, which are critical for survival with good outcomes [ ] (see Fig. 1 ).