We have been privileged to put together a state-of-the-art book called “Textbook of Emergency Cardiology.” For this we assembled a team of co-authors that are superb researchers, clinicians, and teachers in the fields of cardiology and emergency medicine.
This ensures that the readers will get a solid exposure with regard to current conceptsinpathogenesis, diagnosis, and treatment of every cardiovascular emergency that “rolls into the emergency department or hospital.” Thus, from medical or nursing student, to the intern or resident or fellow, and through to an experienced staff attending physician, this book should become a useful tool for everyday medical use.
Cardiac arrest has been defined as the cessation of cardiac mechanical activity confirmed by the absence of signs of circulation.
Any arrest in an adult is presumed to be of cardiac etiology unless it is known, or likely to have been caused by another noncardiac cause as best determined by the healthcare provider.1 Despite important advances in prevention, cardiac arrest continues to affect thousands of individuals each year in both the prehospital and hospital environment. The American Heart Association (AHA) estimates that there were 359,400 adult out-of-hospital cardiac arrests (OHCA) in 2013, with an overall survival rate of 9.5%. This contrasts with the incidence of in-hospital cardiac arrest (IHCA) with an incidence of 209,000 in 2013 and a survival rate of 23.9% in adults.2 This chapter reviews key components of adult cardiac resuscitation in the prehospital and hospital setting.
CARDIAC ARREST IN THE PREHOSPITAL SETTING
Emergency medical service (EMS) response to cardiac arrest usually begins with a layperson in the community and ends with the transfer of the patient to an emergency department.
Over the last three decades, public health initiatives have attempted to improve the outcomes for OHCA.
These efforts have focused on layperson education and recognition early activation of EMS, improving access to automated external defibrillation devices [automated external defibrillator (AED)]and increasing public edu-cation in cardiopulmonary resuscitation (CPR).3,4 Dueto these efforts, according to the AHA’s update report in 2013, 79% of the lay public were confident that they knew what actions to take in a medical emergency, 98% recog-nized the function of an AED and 60% were familiar withCPR.2Despite the general public familiarity with CPR and AEDs, several studies have shown that the translation of this knowledge into practice remains poor.5-7 This is of particular importance as the majority of OHCA occur ata patient’s home, and less than half of these arrests arewitnessed by bystanders.8 One of the primary responsibilities of a layperson first responder is to call 911 and activate EMS immediately. Depending on the type of dispatch center contacted, there may be a trained EMS dispatcher who is able to provide bystanders with instructions prior to the arrival of an ambulance.
Dispatchers are able to assist nontrained bystanders with recognizing cardiac arrest, providing CPR instructions and aiding with the location of an AED.
Theguidance provided by EMS dispatchers has been shown to nearly double the rate of bystander CPR.9 It is important to recognize that EMS providers have different levels of training and capabilities when treating patients following OHCA.
Although differentiatingbetween the various training levels of emergency medical technicians (EMTs) is not the focus of this chapter, medical providers should be aware that EMS systems will vary in the scope of life-saving interventions they are able to provide.
These prehospital medical services will include a combination of basic life support (BLS), advanced cardiac life support (ACLS) and advanced airway management.10 The level of training and care provided in the prehospital setting may have an impact on patient outcomes.
Bakaloset al.performed a meta-analysis in 2011 comparing BLS and ACLS and showed an increase in survival for cardiac arrest patients who received ACLS level care in the prehospital setting [odds ratio (OR) = 1.47].11 Patient age, gender, initial cardiac rhythm, bystander CPR, and early defibrillation are all variables known to impact outcomes in out-of-hospital cardiac arrest.12 A patient’s socioeconomic status may also have an influence on outcomes.
Vaillancourt et al. showed an association between socioeconomic status and rates of bystander CPR, with decreased likeliness of receiving bystander CPR associated with lower socioeconomic status.13 In addition, a large emphasis has been placed on EMS scene response time for patients with OHCA. This emphasis is appropriate for patients experiencing OHCA due to association between survival rates and the time to arrive by EMS.14 Even in the setting of a bystander .