**4.1 Basic life support (BLS)**

In Hungary, the average arrival of an ambulance is 5–8 minutes, and the first shock is delivered 8–11 minutes after the announcement [13]. During this time, the survival of the patient is in the hands of the layman. The use of BLS and the use of an automated external defibrillator (AED) can significantly improve long-term survival.

Patient survival is determined by elements of the chain of survival from circulatory arrest. It includes early recognition of cardiac arrest and calling for help, circulatory maintenance with high-quality chest compression and rescue breathing, early defibrillation (if necessary), and post-cardiac arrest intensive care after achieving return of spontaneous circulation (ROSC) (**Figure 2**).

The survival chain shown in the figure symbolizes the steps required to perform the circulatory arrest. The first three steps on site can be done by anyone. Abbreviations: AED: Automated External Defibrillator.

### *4.1.1 How to recognize a sudden cardiac arrest?*


## *4.1.2 What to do in case of sudden cardiac arrest?*

How to call for help?


**Figure 2.** *The survival chain (own flowchart).*

*Out-of-Hospital Cardiac Arrest in General Population and Sudden Cardiac Death in Athletes DOI: http://dx.doi.org/10.5772/intechopen.101813*

How to perform quality chest compression?


How to perform rescue breath?


#### *4.1.3 AED-PAD program*

Local-regional AED-PAD (automated external defibrillator–public access defibrillation) programs are essential to reduce time till return of spontaneous circulation, the central nervous system ischemic injury, and to improve survival. In the case of a shockable rhythm, defibrillation within 3–5 minutes of collapse can result in survival of up to 50–70% [13–15]. Delaying defibrillation reduces survival by approximately 10–12% per minute. AEDs are easy to use, but proper training is required to master them properly. The PAD program aims to reduce the number of deaths due to sudden cardiac arrest in public places. The AED is to be located in high-traffic areas that are accessible to all, e.g., airports, stadiums, schools, shopping malls. It helps laypeople with simple voice instructions during resuscitation. Based on a defined algorithm, it performs a rhythm analysis every 2 minutes and, if it detects a rhythm to be shocked, charges the defibrillation capacitor, and then the resuscitator can deliver the shock with the push of a highlighted button.

#### **4.2 Advanced life support (ALS)**

The ERC guidelines are based on the 2020 ILCOR CoSTR. There have been no significant changes to the 2021 adult ALS guidelines [11]. Priority remains on highquality chest compression with minimal interruption and early defibrillation. Chest compression should be paused only when necessary, for as short a time as possible, in the event of a shock, care should be taken not exceeding 5 seconds. The use of airway management devices must comply with the principle of gradation, i.e., from the simplest to the more complex. There has also been no change in resuscitation drugs. In the case of a non-shockable rhythm, 1 mg of adrenaline should be used as soon as possible, and in the case of a shockable rhythm, an additional 1 mg of adrenaline should be given every 3–5 minutes after the third shock and until the return of spontaneous circulation. If the shockable rhythm cannot be terminated, an iv. bolus of 300 mg amiodarone after the third shock, an additional iv. bolus of

150 mg amiodarone should be given after the fifth shock. During the advanced life support, the aim is to clarify reversible causes according to 4H/4 T: hypoxia, hypo-hyperkalemia, hypovolemia, hypothermia, thromboembolism (coronary, pulmonary), toxin, tamponade, tension pneumothorax. The new guideline recognizes the growing role of bedside point-of-care ultrasound (POCUS) in clarifying the etiology, but stresses the need for a competent handler and to minimize interruptions during chest compression associated with the use of POCUS. The guidelines also reflect the consideration of increasingly evidence-based extracorporeal techniques (eCPR) as rescue therapy to facilitate ALS failure and to facilitate certain interventions (coronary angiography, percutaneous coronary intervention, pulmonary thrombectomy).
