the PAD trial [23, 24].
Figure 12.1 Contributors to cardiac arrest survival. While the first links of cardiac arrest care (early 9‐1‐1, early bystander CPR, and early defibrillation) contribute to cardiac arrest survival, ALS care does not.
Source: Stiell IG, Wells GA, Field B, et al. Advanced cardiac life support in out‐of‐hospital cardiac arrest. N Engl J Med. 2004; 351:647–56. © 2004 Massachusetts Medical Society. All rights reserved.
The average survival to hospital discharge after OHCA is estimated to be between 5% and 10%, but reported OHCA survival rates also vary widely [4,25–29]. There are likely several reasons for this, including differing denominators, varying definitions of survival, and possibly true regional differences [24]. In CARES, which comprises more than 1,800 EMS agencies covering a catchment area of nearly 152 million people, an eight‐fold difference in survival (2.5–21.1%) was found between sites with at least 150 cardiac arrests annually. Cases witnessed by bystanders and presenting with shockable rhythms also had an eight‐fold difference in survival (7.7–64%), and rates of bystander CPR had a five‐fold difference (14.6–77.8%) [6].
Elements of a Community Cardiac Arrest Care System
The key elements of a community cardiac arrest care system were initially described in the “chain of survival.” However, for this to be effective, there need to be other supporting pre‐requisites within the system. This can be depicted in the “frame of survival”, which has the chain of survival at its core, encapsulated by the prerequisites (Figure 12.2). The inner frame depicts pre‐requisites that are within the control of local EMS, while the outer frame are those subjected to governmental bodies. The EMS medical director has an important role as the bridge between the inner and outer frames.
Such a framework can guide EMS systems at different stages of development. For example, in certain systems, the cultural views of resuscitation may need to be modified for the community element to be effective in improving OHCA survival. Even in more developed systems, the emergency care network can be further developed to allow data sharing to improve OHCA survival outcomes [30]. Community‐oriented approaches in collaboration with organizational stakeholders are essential in facilitating improved cardiac arrest survival. EMS medical directors and agencies cannot successfully care for victims of OHCA in isolation. They must collaborate with the community to optimize all elements of care and should serve leadership roles in this effort.
Bystander Recognition of Arrest and Calling for Help
The most important first steps in cardiac arrest care are recognition of the event and summoning help. These actions require widespread public understanding of OHCA, how to recognize OHCA, and the importance of immediate action.
The methods for teaching laypersons to recognize OHCA have evolved over recent years. Many studies have described the difficulty and delays caused by laypersons attempting to feel for a pulse [31]. Even trained EMTs had difficulty detecting the presence or absence of a pulse in patients undergoing cardiac bypass during open‐heart surgery [32]. Thus, current American Heart Association (AHA) guidelines advise that bystanders should call 9‐1‐1 and begin treatment for OHCA if the person has no movement and no regular breathing. Bystanders must not mistake agonal gasps for normal breathing [33].
Emergency medical dispatch is essential to cardiac arrest care. Public safety answering points must quickly and accurately recognize potential cardiac arrest calls and promptly dispatch appropriate first responder and EMS units. Providing pre‐arrival instructions for bystander CPR and AED use is another important role for the telecommunicator. Telecommunicator instruction in CPR improves the likelihood of the caller performing CPR (see Chapter 88) [34].
Bystander Cardiopulmonary Resuscitation
Bystander CPR refers to CPR performed by someone who was already present at or passing by the patient’s location. This contrasts with CPR performed by dispatched emergency responders. Bystanders have the earliest opportunity to provide CPR to the cardiac arrest victim. Multiple studies have demonstrated the survival benefit of bystander CPR, as well as the increase in mortality associated with delays in CPR delivery [35, 36]. EMS medical directors and agencies should monitor and optimize the rate of bystander CPR in their communities [37]. Prior efforts have included community education about OHCA and the importance of CPR, increasing access to training, and teaching CPR in schools to develop a culture of bystander assistance.
Table 12.1 CARES Public Reporting of State Aggregate Metrics, 2019.
Source: Reproduced with permission from CARES 2019 Annual Report. Available at: https://mycares.net/sitepages/uploads/2020/2019_flipbook/index.html?page=39. Accessed August 30, 2020. © 2019, MyCares.net.
| State | OHCA Incidence | Non‐Traumatic Etiology Survival Rates | Bystander Intervention Rates | ||||||
|---|---|---|---|---|---|---|---|---|---|
| CARES Cases Reported (n) | 2019 CARES Population Catchment (n) | 2019 Total State Population (n) | Population Covered (%) | Incidence Rate (per 100,000) | Overall Survival to Hospital Discharge (%) | Utstein Survival (%) | CPR (%) | Public AED Use (%) | |
| National | 100,956 | 131,905,913 | 328,239,523 | 40.1 | 76.5 | 10.5 | 33.2 | 41.2 | 12.2 |
| Alaska | 394 | 611,330 | 731,545 | 83.6 | 64.4 | 16.0 | 44.1 | 73.3 | 2.7 |
| California | 16,100 | 24,681,023 | 39,512,223 | 62.5 | 65.2 | 9.0 | 32.1 | 43.5 | 12.0 |
| Colorado | 2,074 | 3,616,495 | 5,758,736 | 62.8 | 57.4 | 12.3 | 39.4 | 41.7 | 15.1 |
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