Prehospital Emergency Care
ISSN: 1090-3127 (Print) 1545-0066 (Online) Journal homepage: http://www.tandfonline.com/loi/ipec20
Assessment of the Safety and Effectiveness of Emergency Department STEMI Bypass by Defibrillation-only Emergency Medical Technicians/Primary Care Paramedics Garry Ross ACP, Thamir Alsayed MD, SBEM, Linda Turner PhD, Chris Olynyk ACP, Adam Thurston ACP, RN & P. Richard Verbeek MD, FRCPC To cite this article: Garry Ross ACP, Thamir Alsayed MD, SBEM, Linda Turner PhD, Chris Olynyk ACP, Adam Thurston ACP, RN & P. Richard Verbeek MD, FRCPC (2015) Assessment of the Safety and Effectiveness of Emergency Department STEMI Bypass by Defibrillation-only Emergency Medical Technicians/Primary Care Paramedics, Prehospital Emergency Care, 19:2, 191-201 To link to this article: http://dx.doi.org/10.3109/10903127.2014.959226
Published online: 08 Oct 2014.
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Date: 05 November 2015, At: 19:40
ASSESSMENT OF THE SAFETY AND EFFECTIVENESS OF EMERGENCY DEPARTMENT STEMI BYPASS BY DEFIBRILLATION-ONLY EMERGENCY MEDICAL TECHNICIANS/PRIMARY CARE PARAMEDICS Garry Ross, ACP, Thamir Alsayed, MD, SBEM, Linda Turner, PhD, Chris Olynyk, ACP, Adam Thurston, ACP, RN, P. Richard Verbeek, MD, FRCPC
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ABSTRACT
for path 1 were 6 (IQR 5) minutes to reach the nearest nonPCI center ED and 66 (IQR 45) minutes to the PCI center ED compared to a median predicted 13 (IQR 7) minutes to a PCI center ED had EMT-Ds/PCPs followed a direct path. Median transport time for path 2 was 12 (IQR 8) minutes compared to a median predicted time of 11 (IQR 6) minutes had no EMT-P/ACP rendezvous occurred. Median transport time for path 3 was 7 minutes (IQR 5). Three patients experienced prehospital cardiac arrest; 1 required dopamine, and 4 others received a saline bolus for hypotension. Conclusions. Substantial time savings may occur if EMT-Ds/PCPs bypass non-PCI center EDs with only a small predicted increase (about 7 minutes) in the transport time to the PCI center ED. EMT-P/ACP rendezvous does not appear to substantially increase transport time. Given the relatively low occurrence of clinically important events, our findings suggest that EMTD/PCP bypass to a PCI center ED may be safe and effective for selected STEMI patients. Key words: emergency medical services; prehospital emergency care; triage; ST-segment elevation myocardial infarction; percutaneous coronary intervention
Introduction. The American Heart Association (AHA) suggests emergency medical service (EMS) providers transporting ST-segment elevation myocardial infarction (STEMI) patients to a percutaneous coronary intervention (PCI) center require advanced life support (ALS) skills. Objectives. To evaluate the potential safety and time savings effectiveness of defibrillation-only emergency medical technician/primary care paramedic (EMT-D/PCP) EMS transport to a PCI center in a system where only emergency medical technician-paramedics/advanced care paramedics (EMTPs/ACPs) are authorized to bypass non-PCI hospitals. Methods. We reviewed 89 consecutive patients meeting STEMI criteria transported by EMT-Ds/PCPs per protocol by one of three paths: 1) closest non-PCI center emergency department (ED) with secondary transfer by EMT-Ps/ACPs to a PCI lab, 2) rendezvous with EMT-Ps/ACPs and diversion to a PCI lab, and 3) PCI center ED if it was closest. Actual transport times to the PCI center ED were compared to predicted transport times determined by mapping software had EMT-Ds/PCPs followed a direct path. Lastly, we recorded predefined clinically important events and advanced care interventions. Results. Twenty-seven, 51, and 11 patients followed paths 1, 2, and 3 respectively. Median transport times
PREHOSPITAL EMERGENCY CARE 2015;19:191–201
INTRODUCTION Over the past decade, primary percutaneous coronary intervention (PCI) for patients with ST-segment elevation myocardial infarction (STEMI) has become the reperfusion modality of choice especially in urban settings.1 During this time, emergency medical services (EMS) have developed systems of care that authorize paramedics to triage suspected STEMI patients directly to PCI capable centers, often bypassing other closer hospitals.2–6 This is locally known as the CODE STEMI bypass program. Our program largely relies on prehospital care providers whose scope of practice includes the ability to acquire and interpret 12-lead electrocardiograms (ECG) for the presence of STEMI and advanced cardiac life support (ACLS), e.g., advanced airway procedures, synchronized cardioversion, transcutaneous pacing (TCP), intravenous therapy, and typical ACLS medication administration. In Canada, these paramedics are known as advanced care paramedics (ACPs) while in the United States they are generally known as emergency medical technician-paramedics (EMT-Ps). This is in keeping with current expert opinion concerning the prehospital management of suspected
Received June 25, 2014 from the Sunnybrook Centre for Prehospital Medicine, University of Toronto, Toronto, Ontario (GR, TA, LT), Toronto Emergency Medical Services, Toronto, Ontario (CO, AT), and Sunnybrook Centre for Prehospital Medicine, Division of Prehospital Care, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (PRV). Accepted for publication July 24, 2014. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. The authors would like to acknowledge and thank Toronto EMS prehospital care providers and affiliated Greater Toronto area hospitals for their dedication and exemplary patient care in advancing CODE STEMI bypass. This paper was presented at the National Association of EMS Physicians annual meeting, Tucson, Arizona, January 16, 2014. Dr. Alsayed is currently Emergency Medicine Consultant, EMS Physician, Division Head and EMS Director, King Fahd Hospital of the University, Al Khobar, Saudi Arabia Address correspondence to P. Richard Verbeek, MD, FRCPC, Sunnybrook Centre for Prehospital Medicine, 77 Brown’s Line, Suite 100, Toronto, ON M8W 3S2, Canada. E-mail: richard.verbeek@ sunnybrook.ca doi: 10.3109/10903127.2014.959226
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STEMI patients that states, “All emergency ambulances should be equipped with ECG recorders, defibrillators, and at least one person on board trained in advanced life support”7 and “EMS providers should be trained to respond to cardiovascular emergencies, including ACS [acute coronary syndromes] and its acute complications.”8 However, in Canada, the majority of prehospital care providers are trained as primary care paramedics (PCPs), whose scope of practice related to STEMI is limited to 12-lead ECG acquisition and interpretation, ASA, nitroglycerin, and defibrillation. In the United States, outside of 12-lead ECG acquisition, these prehospital care providers are generally known as defibrillation-only emergency medical technicians (EMT-Ds). For clarity throughout, the paper uses the combined terms EMT-P/ACP and EMT-D/PCP. The above expert opinion7,8 creates a dilemma as to where an EMT-D/PCP should transport a STEMI patient. Since the EMT-D/PCP scope of practice does not meet the stated expert opinion to engage in CODE STEMI bypass, one might conclude, for patient safety, that EMT-Ds/PCPs should transport the patient to the closest hospital followed by a secondary interfacility transfer by EMT-Ps/ACPs. However, in doing so, the time to primary PCI balloon inflation and total myocardial ischemic time increases, both thought to be associated with increased mortality.9,10 Two recent reports have suggested that CODE STEMI patients who have stable vital signs on initial assessment do not commonly experience clinically important events nor frequently require advanced cardiac interventions beyond defibrillation,11,12 a skill that is now within the scope of practice of all EMTDs/PCPs and EMT-Ps/ACPs. These reports are encouraging in that they provide a possible safety signal to support EMT-D/PCP involvement in CODE STEMI bypass. Accordingly, our objectives were to further investigate the potential clinical safety and time-saving effectiveness of EMT-D/PCP CODE STEMI bypass by conducting a comprehensive review of all CODE STEMI patients identified by Toronto EMS PCPs over 16 months beginning January 1, 2012.
METHODS Setting and CODE STEMI Bypass Program Description Toronto EMS provides a single “third” service response to the city of Toronto.13 The service provides coverage for a geographic area of 650 km2 with a daytime population of about 3.5 million people, making it the largest municipal paramedic service in Canada. Toronto EMS responds to approximately 300,000 incidents annually. There are 901 paramedics, of whom approximately 65% are EMT-Ds/PCPs and 35% are
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EMT-Ps/ACPs. CODE STEMI bypass was introduced in May 2008. Since then, EMT-Ps/ACPs have participated fully in the program by performing up to three serial 12-lead ECGs on patients presenting with suspected ischemic chest pain,14 using a combined computer and manual interpretation of the ECG, and directly transporting STEMI patients to one of six PCI centers, bypassing the closest hospital emergency department (ED) if it is not a PCI-capable center. During the first year of CODE STEMI bypass, 342 STEMI patients were identified.11 In the fall of 2011, EMT-Ds/PCPs were trained to acquire and rely on computer interpretation of serial 12-lead ECGs to identify STEMI. They were also provided with training in transport protocols. EMTDs/PCPs began limited participation in the CODE STEMI program in January 2012. Limited participation means that EMT-Ds/PCPs could only transport a STEMI patient to the closest ED. However, they could rendezvous with an EMT-P/ACP crew if one was available, which resulted in direct transport to a PCI lab. Thus, once an EMT-D/PCP identified a CODE STEMI patient, one of three transport “paths” were taken, depending on location, availability of an EMTP/ACP crew, and proximity of a PCI center. 1. Path 1 is EMT-D/PCP transport to the closest non-PCI center ED with a secondary interfacility transfer by EMT-Ps/ACPs to the PCI center. 2. Path 2 is a rendezvous en route with EMTPs/ACPs and transport directly to the nearest PCI lab. A rendezvous could occur either at the patient pickup address, during EMT-D/PCP transport to a non-PCI center ED, or outside of the nonPCI center ED – all of which result in transport by EMT-Ps/ACPs directly to the PCI lab. 3. Path 3 is EMT-D/PCP transport to the PCI center ED if it is the closest destination ED.
Identification of Subjects Cases were retrospectively identified by searching for EMT-D/PCP electronic patient care reports (ePCRs) between January 1, 2012, and April 30, 2013, that contained the word “STEMI” based on EMT-D/PCP computerized ECG interpretation where STEMI diagnosis was defined as ∗∗ Acute MI∗∗ being reported by GE/Marquette 12-SL software in the Zoll E-series defibrillator/cardiac monitors (ZOLL Medical, Chelmsford, MA). We then excluded known do not resuscitate (DNR) patients (according to program policy) and ePCRs where the ECG interpretation was recorded as “STEMI negative.” We also excluded cases where an EMT-P/ACP arrived at the pickup address less than 5 minutes after the EMT-D/PCP crew, since it was deemed that the EMT-D/PCP crew would not have been able to obtain a full 12-lead ECG and make a
G. Ross et al.
determination of STEMI in that 5-minute interval. The remaining ePCRs contained the words “STEMI positive” reflecting the 12-lead ECG statement ∗∗ Acute MI∗∗ described above. Final case identification was conducted by two physicians (TA and PRV) via a blinded review of the corresponding 12-lead ECGs and the ePCR documentation. Cases were included where physicians agreed with the computer interpretation of STEMI and if at least one of the following were true: 1. EMT-D/PCP documented agreement with the computer interpretation 2. EMT-D/PCP informed EMS dispatch of STEMI 3. EMT-D/PCP took actions supporting belief of STEMI
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Initial interrater physician agreement was determined using a kappa value, with the final decision for inclusion/exclusion based on consensus review.
Transport Path and Transport Times For each transport path, transport times were determined using recorded (actual) or derived (predicted) values. Actual transport times were taken directly from Toronto EMS electronic dispatch data, which records actual times according to an atomic clock. Predicted transport times were derived times determined by using mapping software (Microsoft MapPoint 2010, Microsoft, Redmond, WA) currently used by Toronto emergency medical dispatchers to predict the transport time from the location of an EMS call to a designated ED. Using arrival at the ED resulted in a final common accurate time stamp for analysis of all actual and predicted transport times. Actual and predicted transport times for each transport path were determined as follows: For path 1, the actual transport time was the actual time from leaving the pickup address until arrival at the PCI center ED. This included the transport time to the closest non-PCI center ED, the additional time interval spent there, and secondary interfacility transfer time to the PCI center ED. The predicted transport time was the predicted time that would have been taken for an EMT-D/PCP transport directly to the PCI center ED, thus bypassing the non-PCI center. For path 2 (i.e., EMT-D/PCP rendezvous with an EMT-P/ACP), the actual transport time was the actual time taken from leaving the pickup address until arrival at the PCI center ED, inclusive of rendezvous time. The predicted transport time was the predicted time taken had the EMT-D/PCP transported the patient directly to the PCI center ED with no rendezvous, again, bypassing the closer non-PCI center if the PCI center was not the closest center. We also recorded the predicted travel time to the closest non-PCI center ED.
For path 3, the actual transport time was the actual time taken from leaving the pickup address until arrival at the PCI center ED. The predicted transport time was the predicted time to the same center according to the mapping software and serves as a clinically relevant validation of the predicted times compared with actual times.
Demographic and Clinical Data Patient clinical and demographic characteristics, including age, gender, past medical history, cardiac medication, and vital signs, were recorded. The following predefined clinically important events (CIEs) were abstracted: cardiac arrest, hypotension (systolic blood pressure