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Diagnostic performance and potential clinical impact of advanced care paramedic interpretation of ST-segment elevation myocardial infarction in the field

Published online by Cambridge University Press:  21 May 2015

Michel R. Le May*
Affiliation:
University of Ottawa Heart Institute, Ottawa, Ont
Richard Dionne
Affiliation:
Ottawa Base Hospital Program, Ottawa, Ont Department of Emergency Medicine, University of Ottawa, Ottawa, Ont
Justin Maloney
Affiliation:
Ottawa Base Hospital Program, Ottawa, Ont Department of Emergency Medicine, University of Ottawa, Ottawa, Ont
John Trickett
Affiliation:
Ottawa Base Hospital Program, Ottawa, Ont
Irene Watpool
Affiliation:
Ottawa Base Hospital Program, Ottawa, Ont
Michel Ruest
Affiliation:
Ottawa Paramedic Service, Ottawa, Ont
Ian Stiell
Affiliation:
Department of Emergency Medicine, University of Ottawa, Ottawa, Ont
Sheila Ryan
Affiliation:
University of Ottawa Heart Institute, Ottawa, Ont
Richard F. Davies
Affiliation:
University of Ottawa Heart Institute, Ottawa, Ont
*
Ottawa Heart Institute, 40 Ruskin St., Ottawa ON K1Y 4W7

Abstract

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Objectives:

Most studies of pre-hospital management of ST-elevation myocardial infarction (STEMI) have involved physicians accompanying the ambulance crew, or electrocardiogram (ECG) transmission to a physician at the base hospital. We sought to determine if Advanced Care Paramedics (ACPs) could accurately identify STEMI on the pre-hospital ECG and contribute to strategies that shorten time to reperfusion.

Methods:

A STEMI tool was developed to: 1) measure the accuracy of the ACPs at diagnosing STEMI; and 2) determine the potential time saved if ACPs were to independently administer thrombolytic therapy. Using registry data, we subsequently estimated the time saved by initiating thrombolytic therapy in the field compared with in-hospital administration by a physician.

Results:

Between August 2003 and July 2004, a correct diagnosis of STEMI on the pre-hospital ECG was confirmed in 63 patients. The performance of the ACPs in identifying STEMI on the ECG resulted in a sensitivity of 95% (95% confidence interval [CI] 86%–99%), a specificity of 96% (95% CI 94%–98%), a positive predictive value (PPV) of 82% (95% CI 71%–90%), and a negative predictive value (NPV) of 99% (95% CI 97%–100%). ACP performance for appropriately using thrombolytic therapy resulted in a sensitivity of 92% (95% CI 78%–98%), a specificity of 97% (95% CI 94%–98%), a PPV of 73% (95% CI 59%–85%) and an NPV of 99% (95% CI 97%–100%). We estimated that the median time saved by ACP administration of thrombolytic therapy would have been 44 minutes.

Conclusions:

ACPs can be trained to accurately interpret the pre-hospital ECG for the diagnosis of STEMI. These results are important for the design of regional integrated programs aimed at reducing delays to reperfusion.

Type
Original Research • Recherche originale
Copyright
Copyright © Canadian Association of Emergency Physicians 2006

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