CHAPTER 92: CARDIOPULMONARY AND CARDIOCEREBRAL RESUSCITATION

DEFINING SUDDEN CARDIAC ARREST

Cardiac arrest is defined as the cessation of cardiac mechanical activity, as confirmed by the absence of signs of circulation. Cardiac arrest is traditionally categorized as being of cardiac or noncardiac origin. An arrest is presumed to be of cardiac origin unless it is known or likely to have been caused by trauma, submersion, drug overdose, asphyxia, exsanguination, or any other noncardiac cause as best determined by rescuers.¹

It is challenging to define what “unexpected” or “sudden” death is. Current practice defines sudden cardiac death as unexpected death without an obvious noncardiac cause that occurs within 1 hour of symptom onset (witnessed) or within 24 hours of last being observed in normal health (unwitnessed).²

EPIDEMIOLOGY OF OUT-OF-HOSPITAL CARDIAC ARREST

The following is based on American Heart Association (AHA) statistical data from 2015¹:

• Each year 326,000 people experience emergency medical services (EMS)-assessed out-of-hospital cardiac arrests in the United States.

• Approximately 60% of out-of-hospital cardiac arrests are treated by EMS personnel.³

• Twenty-five percent of those with EMS-treated out-of-hospital cardiac arrest have no symptoms before the onset of arrest.⁴

• Among EMS-treated out-of-hospital cardiac arrests, 23% have an initial rhythm of ventricular fibrillation (VF) or ventricular tachycardia (VT) or are shockable by an automated external defibrillator.⁵

• The incidence of cardiac arrest with an initial rhythm of VF is decreasing over time; however, the incidence of cardiac arrest is not decreasing.⁶

• The median age for out-of-hospital cardiac arrest is 66 years.⁷

• Cardiac arrest is witnessed by a bystander in 38.7% of cases, by an EMS provider in 10.9% of cases, and is unwitnessed in 50.4% of cases.⁷

• In the Cardiac Arrest Registry to Enhance Survival (CARES) registry, 31,127 out-of-hospital cardiac arrests were treated in 2013. Survival to hospital discharge was 10.6% and survival with good neurological function (Cerebral Performance Category 1 or 2) was 8.3%. For bystander witnessed arrest with a shockable rhythm, survival to hospital discharge was 33.0%.⁷

• According to the CARES registry, in 2013 the majority of out-of-hospital cardiac arrests occurred at a home or residence (69.5%).⁷

• A family history of cardiac arrest in a first-degree relative is associated with a twofold increase in risk of cardiac arrest.^8,9

EPIDEMIOLOGY OF IN-HOSPITAL CARDIAC ARREST

Based on the AHA Statistical Data from 2015¹:

• Each year, 209,000 people are treated for in-hospital cardiac arrest in the United States.¹⁰

• According to the Get With The Guidelines (GWTG)-Resuscitation database from 2014, 25.5% of adults who experienced in-hospital cardiac arrest with any first recorded rhythm in 2013 survived to discharge.¹

• In the United Kingdom National Cardiac Arrest Audit database between 2011 and 2013, the overall unadjusted survival rate was 18.4%. Survival was 49% when the initial rhythm was shockable and 10.5% when the ...