EMERGENCY CARDIAC CARE

Emergency Cardiac Care
The impetus for starting paramedic ambulance programs in the United States grew out of the recognition that sudden cardiac death was the leading cause of out-of-hospital deaths in the United States. At the same time, J. F. Pantridge in Belfast, Ireland, investigated bringing the hospital to the patient's side in the form of a mobile coronary care unit to treat life-threatening cardiac arrhythmias and improve patient survival. Subsequently, it was recognized that rather than sending physicians and nurses to the patient's side, that ambulance technicians could be trained to appropriately recognize and treat many cardiac rhythm disturbances, particularly ventricular fibrillation (VF). This resulted in communities having over 20 percent of patients resuscitated successfully from an out-of-hospital cardiac arrest. Over time it became apparent that the most effective treatment for cardiac arrest was rapid electrical defibrillation for patients in VF.

This observation led to the development of automated external defibrillators (AEDs) that could be used by individuals with as little as 2 to 4 h of training. Currently, the American Heart Association (AHA) recommends that AEDs be available for all individuals who may respond to cardiac emergencies and, in addition, has proposed that they be distributed widely in communities in a program known as Public Access Defibrillation. Observations from casinos and airports found that bystanders or trained security personnel could use a publicly accessible AED to obtain a survival rate of over 50 percent for victims of sudden cardiac arrest.

With the advent of reperfusion therapy for AMI, Emergency Medical Services systems have attempted to identify patients in the field who may benefit from this intervention. Some systems perform 12-lead ECGs in the field and notify hospitals if the patient has ECG evidence of an AMI so that the hospital may prepare to intervene promptly on patient arrival, reducing the time needed to initiate reperfusion therapy.

In addition, thrombolytic agents also may be given by paramedics; a meta-analysis of six studies indicated that prehospital thrombolytic administration decreases time to drug administration and in-hospital mortality. For patients with angina and unstable angina, there is evidence that prehospital drug therapy (nitroglycerin and aspirin) improves the patient's symptoms and reduces hospital use.