Cardiopulmonary Arrest

Cardiopulmonary Arrest

INTRODUCTION

Cardiopulmonary arrest is the abrupt cessation of spontaneous and
effective ventilation and circulation following a cardiac or respiratory
event.1 CPR provides artificial ventilation and circulation until
it is possible to provide advanced cardiac life support (ACLS) and
reestablish spontaneous circulation. In the United States, there are
more than 460,000 victims of sudden cardiac arrest each year with
most occurring outside the hospital. The annual incidence of
sudden cardiac arrest has been estimated to be approximately 0.55
per 1,000 population and in the United States, sudden cardiac death
represents up to 15% of total mortality.

Early attempts at resuscitation date back to the biblical era.8
Modern-day resuscitation began in the late 1950s when it was
discovered that expired air delivered via a mouth-to-mouth technique
can maintain adequate oxygenation of blood.9 Later, in 1960,
Kouwenhoven and colleagues described “closed chest cardiac massage,”
and together with mouth-to-mouth ventilation, modern-day
CPR was born.

EPIDEMIOLOGY

In an adult patient, cardiopulmonary arrest usually results from the
development of an arrhythmia. Most cardiac arrests take place
outside the hospital, and most patients have underlying acute or
chronic heart disease. In more than two-thirds of patients, cardiac
arrest occurs as the first manifested clinical event with no preceding
symptoms or warning. Although the most common arrhythmia is
either VF or PVT, the number of patients with out-of-hospital
cardiac arrests presenting with VF as the initial rhythm has changed
dramatically.

In one study, the number of patients with VF was
61% in 1980 compared with only 41% in 2000, a reduction of
greater than 30%. A similar trend was noted with in-hospital
cardiac arrest as one study reported the number of patients presenting
with VF or PVT as the initial rhythm to be only 23%. Hospital
survival for in-hospital cardiac arrest related to VF or PVT is
approximately 36% with 75% having a good neurologic outcome.
Survival for out-of-hospital cardiac arrest caused by VF or PVT is
25% to 40%, with higher survival rates being observed in communities
that have a rapid response system.

In contrast to adult patients, only 15% of pediatric patients
present with VF or PVT as the initial rhythm. This is probably
because most pediatric arrests are respiratory-related as opposed to
the primary cardiac etiology seen in adult patients. Unfortunately,
survival following pediatric out-of-hospital cardiopulmonary arrest
ranges only from 2% to 10%, with most survivors having a poor
neurologic status.

ETIOLOGY

The most common cause of cardiopulmonary arrest in adult
patients is an acute myocardial infarction (MI) or pulmonary
embolism (PE) representing more than 70% of victims. In pediatric
patients, conversely, cardiopulmonary arrest is often the terminal
event of progressive shock or respiratory failure. The cause of
cardiac arrest varies with age, the underlying health of the child, and
the location of the event. Out-of-hospital arrests frequently are
associated with events such as trauma, sudden infant death syndrome,
drowning, poisoning, choking, severe asthma, and pneumonia.
In-hospital pediatric arrests are associated with sepsis,
respiratory failure, drug toxicity, metabolic disorders, and arrhythmias.
Pediatric out-of-hospital arrest generally presents with
hypoxia and hypercarbia progressing to respiratory arrest and
bradycardia and finally to asystolic cardiac arrest.

CLINICAL PRESENTATION

Symptoms

■ Anxiety, change in mental status or unconscious
■ Cold, clammy extremities
■ Dyspnea, shortness of breath or no respiration
■ Chest pain
■ Diaphoresis
■ Nausea and vomiting
Signs

■ Hypotension
■ Tachycardia, bradycardia, irregular or no pulse
■ Cyanosis
■ Hypothermia
■ Distant or absent heart and lung sounds