New developments in cardiopulmonary resuscitation. Since the last revision of the American Heart Association's guidelines in 1985, several new developments of clinical importance have occurred in the field of cardiopulmonary resuscitation. These include enhanced access to and earlier use of defibrillation, the use of high-dose epinephrine when standard doses fail, the assessment of resuscitative efforts with end-tidal CO2 monitoring and the addition of two new drugs, amiodarone (for refractory ventricular fibrillation) and adenosine (for paroxysmal supraventricular tachycardia). Time will determine the ultimate role of these advancements in the management of cardiac arrest. 