Prehospital triage essential for cost-effective paramedic-administered thrombolysis

Prehospital Triage Essential for Costeffective Paramedic-administered Thrombolysis Mark Sherrid. MD Prehospital administration of thrombolysis on scene eliminates hospital delays and transport delays . There have been several reports of prehospital initiated thrombolysis. This approach has been shown to be feasible for both physician and paramedic staffed emergency ambulances. When paramedics have initiated treatment, they have acted under the instructions of a hospital-based physician.1.2 A 12-lead ECG is transmitted via modem to the emergency department (ED) for physician review before treatment is begun. This strategy has been shown to decrease the time to treatment substantially. It has been shown to be safe . Paramedics already carry multiple pieces of equipment including a stretcher, defibrillator/monitor, medication kit, ambu bag, and oxygen tank to each call. Adding to this equipment burden poses a substantial logistic problem. The combination of a 12lead ECG and the defibrillator/monitor represents a substantial advance as it decreases the paramedic equipment burden. To facilitate rapid acquisition of ECGs in the field there is room for im p ro vem ent in the lead systems of 12-lead machines. Of all calls for one paramedic unit. acute myocardial infarction (AMI) with ST elevation is an uncommon event. Only 5 % of ambulance calls for chest pain have myocardial infarction with 5T elevations and meet current clinical criteria for treatment with thrombolysis.' The low frequency of candidates for treatment leads to the usual problems seen with any equ ipment or drug used infrequently. The low number of eligible patients also raises questions about the cost effectiveness of equipping and training every paramedic with a relatively expensive ECG machine and thrombolytic drug. This barrier should not be underestimated by those interested in establishing a system for delivering prehospital thrombolysis. The

low yield problem has already led to attrition of several groups who have attempted to implement community-wide prehospital thrombolysis. For this reason, triage strategies to increase the yield of patients who are candidates for therapy are indicated. Strategies for effective triage are vital for cost effective prehospital thrombolysis . In the ideal system, the thrombolysis equipped paramedics see all of the acute ischemic syndromes while the other ambulance teams see cases of noncardiac chest pain. Local strategies for effective triage will in crease the yield of treated patients to above 5% of calls for chest pain. Examples of triage strategies are the following: I . Dispatcher triage: Dispatch of thrombolysisequipped ambulances only to patients with typical history for ischemia and appropriate demographics, i.e., patients >40 years old with typical pain. 2. Staged rapid response: Centers are established that provide thrombolysis-equipped paramedics. available on immediate call. only after screening paramedics on scene identify likely candidates."

References I. Kennedy JW. Weaver WD: Potential use of thrombolytic therapy before hospitalization. Am J Cardiol

64(2) :8A.1989 2. Sherrid M. Greenberg H. Marsella Ret al: A pilot study

of paramedic-administered. preho spital thrombolysis for acute myocardial infarction . Clin Cardiol 13:421. 1990 3. Weaver WD, Eisenberg MS. Martin JS et al: Myocardial infarction triage and intervention project-phase I : patient characteristics and feasibility of prehospital initiation of thrombol ytic therap y. J Am Cardiol 15:925, 1990 4. Hartman J. McKeever L. Bufazino V et al: A system approach to IV thrombolysis in acute myocardial infarction in community hospitals: the influence of paramedics. Clin Cardiol 11 :812, 1988

From the Division of Cardiology. St. l.uke's-Roosevelt Hospital. Columbia University, Co{{tgt of Physiciansand Surgtons. New York. New York.

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