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Stapczynsk.i JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD.

Tintinalli's Emergency Medicine: A Comprehensive Study

C!utde. 7_th ed. New York, NY: McGraw-Hill, 20 l l, pp. l-4.

NatiOnal Highway Traffic Safety Administration. The National EMS

Scope of Practice Model. DOT HS 810 657. Washington, DC:

National Highway Traffic Safety Administration, 2007.

Cardiopulmonary Arrest

Katheri ne M. Hil ler, MD

Key Points

• Cardiac disease is the most common cause of nontraumatic death in the Un ited States.

• There are more than 300,000 sudden cardiac deaths

(SCD) each year in the United States. The survival rate of

INTRODUCTION

Cardiopulmonary arrest is defined by unconsciousness,

apnea, and pulselessness. Sudden cardiac death (SCD) is

associated with an underlying history of coronary artery

disease (CAD), but an acute thrombotic event is causal in

only 20-40% of cardiac arrests. Twenty-five percent of

cardiac arrests may have a non cardiac origin ( eg, pulmo -

nary embolus, respiratory arrest, drowning, overdose). The

most common initial rhythm is ventricular fibrillation

(VF), found in approximately 30% of patients. Asystole

and pulseless electrical activity (PEA) are the next most

common presenting rhythms.

The risk of SCD is 4 times higher in patients with

coronary artery disease risk factors and 6-10 times higher

in patients with known heart disease. Structural heart

disease ( eg, cardiomyopathy, heart failure, left ventricular

hypertrophy, myocarditis) accounts for 1 0% of cases of

SCD. Another 1 0% of SCD cases occur in patients with

no structural heart disease or CAD. These cases are

thought to originate from Brugada syndrome, commotio

cordis, prolonged QT syndrome, and familial ventricular

tachycardia (VT), which all cause dysrhythmias leading

to SCD.

Other risk factors associated with an increased risk of

SCD include smoking, diabetes mellitus, hypertension,

33

sco is dependent on the length of time without a pulse,

the underlying cardiac rhythm, and comorbidities.

• Early and uni nterrupted chest compressions and early

defi brillation are the keys to successful resuscitation.

dyslipidernia, and a family history of cardiac disease.

Moderate alcohol consumption ( 1-2 drinks per day) is

considered protective, whereas heavy alcohol consumption

(>6 drinks per day) is a risk factor for SCD.

Despite advances in the field of cardiac resuscitation,

the survival rate of out-of-hospital SCD is estimated to be

3-8%. Survival to discharge in out-of-hospital SCD is

largely determined by the presenting rhythm. Patients with

VF are 15 times more likely to survive to discharge than

patients in asystole (34% vs 0-2%).

CLINICAL PRESENTATION

� History

Obtain history from paramedics, bystanders, or any available family members. Inquire about medications, past

medical history, allergies, trauma, and events leading up to

SCD.

� Physical Examination

Do not halt treatment (including chest compressions and

bag-valve-mask ventilation) to perform a complete physical exam. If the patient has an endotracheal tube in place,

verify position by using end-tidal C02 capnography or

capnometry.

DIAGNOSTIC STUDIES

� Laboratory

CHAPTER 10

If the patient has a return of spontaneous circulation

(ROSC), order a complete blood count, electrolytes, renal

function, and myocardial markers (ie, troponin).

Coagulation studies, an arterial blood gas, and a lactate

may also be useful.