sudden cardiac arrest
arrest
(a-rest') [Fr. arester fr L. arrestare, to stop]active phase arrest
bradyasystolic arrest
cardiac arrest
Etiology
Coronary artery disease is present in most victims. Cardiac arrest is usually caused by myocardial infarction or ventricular arrhythmias. Contributing causes include cardiomyopathies, valvular heart disease, diseases of the electrical conducting system of the heart (such as the long QT syndrome or the Wolff-Parkinson-White syndrome), myocarditis, chest trauma, severe electrolyte disturbances, and intoxications with drugs of abuse or prescribed agents, e.g., digitalis. Physical exertion or extreme emotional stress sometimes precipitates cardiac arrest.
Symptoms
Abrupt loss of consciousness, followed by death within an hour of onset, is the typical presentation of cardiac arrest.
Treatment
Opening the airway, establishing effective respiration, and restoring circulation (with chest compression and defibrillation) are the keys to treating cardiac arrest. The effectiveness of treatment depends upon the speed with which resuscitation begins and upon the patient's underlying condition. Because most episodes of sudden cardiac arrest are unwitnessed, most patients die without treatment (spontaneous recovery from cardiac arrest in the absence of advanced cardiac life support is very rare). For resuscitated patients, therapies include implantable defibrillators, beta blockers, antiarrhythmic drugs, and, in patients with coronary artery disease, modification of risk factors, i.e., treatment of hypertension, smoking cessation, and lipid-lowering diets and drugs. See: table, advanced cardiac life support
| Route | Pros | Cons |
|---|---|---|
| Peripheral IV | Easiest to insert during chest compressions; least traumatic to the patient. | Drugs infused into a peripheral vein take several minutes to reach the heart. |
| Central IV | Drugs and fluids infused into central veins reach the heart in seconds. | Insertion may be difficult during chest compressions, intubation, and defibrillation. Arterial injury, pneumothorax, hemothorax, and other complications are common in emergency insertions. |
| Intraosseous | Drugs and fluids infused into marrow reach the central circulation rapidly. | Clinical experience with IO* insertion is limited relative to IV† insertion. |
| Endotracheal | May be used for drug administration when an airway is present, but other forms of access have not been established. | Double or triple the IV† dose is needed to achieve similar drug effect. Drugs given ET‡ should be diluted in 5–10 ml of sterile water. Correct placement of the ET tube must be confirmed before use. Unlike the other modes of access, this route cannot be used to infuse high volumes of fluids. |