As part of the prevention and treatment of cardiac arrest in the entire country or local community, the system level takes into account the following factors: the proportion of witnessed bystander CPR and PAD use [14,15], intervention of prehospital or in-hospital therapeutic hypothermia (or targeted temperature management), and use of automated mechanical CPR devices or feedback devices [16,17]. The 2020 resuscitation guidelines recommend that key indicators be evaluated, while specific goals to enhance the performance status have been set for the EMS system, local community, and medical institutions providing cardiac arrest treatment (Class IIa, Level B-NR). However, as the current situation in South Korea involves separate management of OHCAs and IHCAs, it may be reasonable for integrated social managements to implement strategies for enhanced survival outcomes and increasing bystander CPR.

A cardiac arrest registry is the essence of measurement. Local communities and EMS systems should establish and monitor the performance data on the social contributors of cardiac arrest survival and related processes. This involves data registration research on all steps of cardiac arrest and patient outcomes at regional community or nationwide levels [11,18]. Continuous measurements will determine if implementing changes leads to improvements. To achieve this, a database should be constructed to integrate registries at the local government, firefighting department, hospitals, national emergency medical center, and the Ministry of Health and Welfare data. In South Korea, the Korea Disease Control and Prevention Agency conducts research to collect and analyze the data on OHCA cases that are then applied in the national statistics. In the US, patient registration systems based on emergency centers have been established. One is the registry for IHCA (Get With The Guidelines-Resuscitation) [19] and the others are statistics for OHCA (Cardiac Arrest Registry to Enhance Survival or Resuscitation Outcomes Consortium Cardiac Registry) [20]. Data from these systems are essential in local community liaisons, monitoring quality improvement activities, managing quality indicators for quality improvement, and successfully enhancing the cardiac arrest survival rate in the local community.

The role of dispatchers or tele-communicators that connect the active EMS system and the general public in emergencies is the critical link in the chain of survival of OHCA. CPR performed by witnesses with the guidance of dispatchers (telephone-assisted CPR or dispatcher-assisted CPR) increases the rate of witness resuscitations in adult OHCA patients. However, it is difficult to accurately determine whether cardiac arrest has occurred in the field over the phone. Dispatchers accurately identify cardiac arrests over the phone in about 70% of cases [21]. If the suspected diagnosis of cardiac arrest is incorrect, the patients will receive inappropriate chest compression or CPR will not begin. Programs that improve the quality of dispatcher-assisted CPR and the feedback from physicians to dispatchers have improved the outcome of cardiac arrest patients. To be able to deliver the CPR guidance over the phone, dispatchers should complete a specific educational program [22]. Specific training of dispatchers on how to deliver telephone-assisted CPR can lead to improved cardiac arrest recognition, reduction of misinterpretation of agonal respiration, increased rate of patients receiving chest compressions, and a shorter time to compression.

We recommend that dispatchers use a standard algorithm to determine cardiac arrest situations through emergency calls (Class I, Level C-LD). To maximize the rate of resuscitation via telephone-assisted CPR, efforts should be made towards the development and active use of guidelines for dispatchers and scripted questions (to determine if a victim is unresponsive with abnormal breathing), and quality improvement through evaluating the debriefing after such telephone instructions and how to receive accurate feedback [23,24]. It is suggested that any dispatchers receive education for potential cardiac arrest situations that include the following: 1) recognizing a cardiac arrest; 2) encouraging the willingness of rescuers to perform CPR and notifying their safety checks; 3) providing instructions to perform chest compression-only CPR and to use an automated external defibrillator (AED); 4) helping the EMS to reach the location of the incident [25,26].

Education about communication during basic life support (BLS) is important in order to overcome barriers that rescuers might experience in performing CPR and use of the AED. There are three main barriers: personal factors (emotional barriers, most often panic, but also socio-economic factors); CPR knowledge (skill deficits, fear of damage or doing something wrong); and procedural issues (e.g., recognition of cardiac arrest, location of AED) [27-29]. Addressing these barriers and enablers to starting CPR might increase the willingness to help those in a life-threatening situation.

Treatment recommendation has not changed since 2010 (strong recommendation, low-certainty evidence). To increase willingness to perform CPR and use AED, laypersons should receive training. CPR training should include the recognition of gasping or abnormal respiration as a sign of cardiac arrest. The EMS dispatcher should provide CPR instruction to callers who report cardiac arrest. If unwilling or unable to perform mouth-to-mouth ventilation, rescuers should be instructed to continue compression-only CPR.

Use of feedback devices during resuscitation training can be effective in improving CPR performance. Since the last search in 2015, based on the evidence of simulation studies and certain clinical studies regarding the use of feedback devices in CPR education, these treatment recommendations have not changed. We suggest the use of feedback devices that provide directive feedback on chest compression rate, depth, decompression, and hand position for improving the CPR performance. If a feedback device is not available, it may be helpful to use a tonal guidance including music or metronome for feedback to only improve the chest compression rate (Class IIa, Level B-R).

The survival of prehospital cardiac arrests is influenced by a range of factors, and one of which is to provide high-quality resuscitation. Appropriate provision of prehospital resuscitation is an important element in determining good neurological prognosis from OHCA [30]. Understanding the impact of ongoing exposure or experience on patient outcomes from OHCA can help with staffing and training strategies. The exposure of EMS personnel is associated with improved short-term survival outcomes [31-33]. In order to increase the level of CPR experience, the national agency or local community should build organically interconnected systems to educate EMS providers, paramedics, relevant educational institutions, and interhospital emergency medical directors through participation in CPR situation or supervising their procedure-focused advanced training.

Unlike the medical staff in hospitals that frequently encounter cardiac arrest patients, field EMS practitioners, including paramedics that provide treatment to OHCAs, are relatively less exposed to actual cardiac arrest management cases. It is reasonable for EMS systems to monitor provider exposure to resuscitation to implement strategies to address issues of low exposure (Class IIb, Level C-LD). Thus, for the effective treatment of OHCA patients, EMS directors are advised to do as follows: 1) manage the experience or exposure of EMS personnel in resuscitation situations; 2) develop strategies, if possible, to address the problem of lack of resuscitation experience, or form a resuscitation team to include members with experience, especially with a recent resuscitation.

High-quality resuscitation training is essential for health care providers (HCPs) at all levels from BLS to ALS, for children and/or adults, depending on their workplace requirement for CPR competencies. Considering the medical staff at hospitals that work in departments with little exposure to cardiac arrest cases, a plan for certified resuscitation education should be developed. A meta-analysis of related studies has shown that resuscitation teams with one or more members having previous participation in an ALS course improve survival outcomes. It is reasonable for HCP to take an adult ALS course or equivalent training. At least one member of the in-hospital resuscitation team should be included in the certified ALS course, while medical staff and HCPs working in a department with higher CPR incidence should provide ALS training in addition to BLS as part of the certified or complementary education (Class IIb, Level C-LD).

Simulation in resuscitation training is widely used and is a well-established educational strategy. It facilitates contextualized learning relating to learner’s reality. Learning CPR can be supported by the use of smartphones, tablets, etc. by using apps and social media, as well as feedback devices. These learning modalities may be teacher-independent. They improve retention and facilitate competency assessment in CPR. The 2020 guideline recommends using e-learning as part of the blended learning approach to reduce the time for conventional face-to-face education in advanced resuscitation. This requires comprehensive management of instructor-led lectures, simulation practices, and testing of conventional education (Class IIa, Level C-LD).

Taking into account these characteristics, learning objectives need to be defined for participating individuals or CPR teams, as well as choosing the adequate equipment. The use of high-fidelity manikins for continuous ALS programs can be effective for learners at training centers with available infrastructure and trained personnel (Class IIa, Level C-LD). If high-fidelity manikins are not available, the use of low-fidelity manikins that are suitable for the standard programs to achieve the educational goals may be considered (Class IIb, Level C-LD). Additionally, the latest tablet-based simulation apps combined with the use of low-fidelity manikins may be suitable alternative at reasonable cost for simulation during resuscitation training.

As cardiac arrest cases are, by nature, not frequently experienced, it is difficult to develop alternative cases for educational purposes. However, advances in technology have allowed us to use new resources for teaching CPR over the past few years [34,35]. Access to medical content has never been easier because of the ubiquitous availability of the internet. Gamified learning (e.g., virtual and augmented reality, smartphones or tablet apps simulating monitors) can be turned into a compression feedback device or become a simulated monitor. Serious games on mobile devices engage CPR learners differently than traditional classroom lessons [35-38]. Virtual learning environments are recommended to be used for pre-course e-learning, as part of a blended learning approach, or self-learning independent of time and location for all levels of courses [39,40]. Therefore, these devices and programs should be included in future CPR educational approaches and combined with face-to-face education (Class IIb, Level B-NR). It might be possible to integrate training related to simulated patients in virtual or augmented reality as a complementary tool to conventional CPR education programs [35].

In unique circumstances that hinder face-to-face training, such as a pandemic or national disaster, conventional education and evaluation of knowledge and performance using general CPR training programs can be replaced with such tools as virtual reality, augmented reality, or web-based contact platforms (Class IIb, Level C-LD). Several contactless platforms for resuscitation education (e.g., self-directed educator, high-frequency methods that apply for the resuscitation quality improvement program) are commercially available in South Korea and other countries. It could be used as a method of complementary education or retraining for HCP as well as noncontact resuscitation education for the general public [41].

Spaced learning (education or retraining separated by longer periods of time) seems to be more effective in CPR training than traditional massed instruction (education provided close together in time) (Fig. 2) [8,17,42-44]. BLS skills decline within 3 to 12 months after initial CPR training, but evidence suggests that more frequent retraining improves CPR skills, responders’ confidence, and willingness to perform CPR (Fig. 3) (Class IIb, Level C-LD) [45].

Recently, rapid response systems (e.g., RRT or medical emergency team) have been operating in South Korea since 2020. RRT has been installed as a type of constant in-hospital monitoring system to prevent the occurrence of cardiac arrest through early intervention before risk of deterioration and cardiac arrest [6,46]. An early warning scoring system and an active in-hospital protocol using the alerting system should be developed alongside the activities of RRT to prevent the incidence of IHCA in adult and pediatric populations. For hospitalized adults, RRT can be effective in reducing the incidence of cardiac arrest, especially in general wards (Class IIa, Level C-LD).

To alert trained lay rescuers of events requiring CPR or PAD use, the use of mobile phone technology by emergency dispatcher systems is reasonable. Notification of lay rescuers via a smartphone app or text message is associated with shorter bystander response times. As these technologies become more ubiquitous, they are likely to play an expanding role in the chain of survival. However, it is recommended that the responders in close proximity to patients with suspected cardiac arrest are advised to ask for help by sending their global positioning system location via smartphone applications and social network systems (text messages) with prior consent (Class IIa, Level B-R).

We suggest a list of TOR rules for adult cardiac arrest patients (prehospital and emergency department settings) [47]. This aims to enable more efficient distribution and use of EMS resources available in the community, to address the issue of increased risk of HCPs and poor CPR quality during transport, and to prevent unnecessary hospital transport. Futile resuscitation could also cause a risk of infection transmission in OHCA patients with emerging infectious diseases [10]. The conventional TOR rules have been validated based on a patient registry in the U.S. and in Asia (Japan and South Korea). The KoCARC (Korean Cardiac Arrest Research Consortium) reports and various regional multicenter studies have been conducted [48-52]. Based on different stages, ten TOR rules have, so far, been developed that can be applied in the prehospital fields [49,53] or in emergency department settings [54] (Table 1) [48-53]. Most TOR rules comprise a stage-by-stage assessment system with consideration of not a single criterion but of multiple conditions, including unwitnessed status, asystole rhythm in the field, no prehospital shock, or ROSC is not achieved prior to arrival at the hospital.

We conditionally recommend the multimodal approach of TOR rules to assist clinicians in deciding whether to discontinue resuscitation efforts out of hospital or to transport to the emergency department with ongoing CPR (Conditional recommendation, Level C-LD). Thus, these prehospital TOR rules are considered a complementary tool in determining whether to terminate resuscitation in the field or to continue resuscitation until arrival at the hospital [50]. Notably, the sole use of the TOR rules should be avoided in deciding to terminate or postpone resuscitation. As the current Emergency Medical Service Acts and laws do not allow the decision to be made solely by paramedics in South Korea, the final decision should be confirmed by the emergency medical director.