Acute coronary syndrome: pharmacotherapy.

Acute coronary syndrome (ACS) refers to the spectrum of cardiac disease, from unstable angina to ST-segment-elevation myocardial infarction. In the emergency medical services (EMS) setting, ACS may be more broadly thought to include patients with chest pain or other symptoms believed to have a cardiac origin who have evidence of ischemia or acute myocardial infarction on a 12-lead electrocardiogram, or symptomatic patients with a previous cardiac event or known cardiac disease. Pharmacologic management of these patients is based on the use of three primary classes of drugs: those that affect clotting, those that establish and maintain hemodynamic control, and those that relieve pain. Many of these agents have been evaluated in large clinical trials for in-hospital use, and a number of ongoing studies are assessing their efficacy in the prehospital setting. The appropriateness of prehospital use of specific agents within each class depends on proper patient selection, the necessity of immediate intervention, ease of use in the field, expertise of EMS personnel, and cost-effectiveness of therapy. This consensus group reviewed agents from all three classes (including aspirin, GPIIb/IIIa inhibitors, unfractionated and low-molecular-weight heparins, fibrinolytics, beta-adrenergic blockers, calcium antagonists, nitrates, and morphine) for their overall indication, applicability to the prehospital setting, and current prehospital use.

Resuscitation in the out-of-hospital setting: medical futility criteria for on-scene pronouncement of death.

The complete and irreversible cessation of life is often difficult to determine with complete confidence in the dynamic environment of out-of-hospital emergency care. As a result, resuscitation efforts often are initiated and maintained by emergency medical services (EMS) providers in many hopeless situations. Medical guidelines are reviewed here to aid EMS organizations with respect to decisions about: 1) initiating or waiving resuscitation efforts; 2) the appropriate duration of resuscitation efforts; and 3) recommended procedures for on-scene or prehospital pronouncement of death (termination of resuscitation). In cases of nontraumatic cardiac arrest, few unassailable criteria, other than certain physical signs of irreversible tissue deterioration, exist for determining medical futility at the initial encounter with the patient. Thus, the general medical recommendation is to attempt to resuscitate all patients, adult or child, in the absence of rigor mortis or dependent lividity. Conversely, wellfounded guidelines now are available for decisions regarding termination of resuscitation in such patients once they have received a trial of advanced cardiac life support. In practice, however, the final decision to proceed with on-scene pronouncement of death for these patients may be determined more by family and provider comfort levels and the specific on-scene environment. For patients with posttraumatic circulatory arrest, the type of injury (blunt or penetrating), the presence of vital signs, and the electrocardiographic findings are used to determine the futility of initiating or continuing resuscitation efforts. In general, patients who are asystolic on-scene are candidates for on-scene pronouncement, regardless of mechanism. With a few exceptions, blunt trauma patients with a clearly associated mechanism of lethal injury are generally candidates for immediate cessation of efforts once they lose their pulses and respirations. Regardless of the medical futility criteria, specialized training of EMS providers and targeted related testing of operational issues need to precede field implementation of on-scene pronouncement policies. Such policies also must be modified and adapted for local issues and resources. In addition, although the current determinations of medical futility, as delineated here, are important to establish for societal needs, the individual patient's right to live must be kept in mind always as new medical advances are developed.