Destination Dilemma: Where Should EMS Transport Stroke Patients?

You  and  your  crew  arrive  at  the home  of  a  70-year-old  female. The patient’s husband tells you his wife is not acting right. Your patient was normal when she awoke this morning, but one hour ago she developed numbness in her right hand and had difficulty speaking. Your stroke assessment is positive and you decide to call a stroke alert. The nearest primary stroke center (PSC) is only seven minutes away where the main treatment offered for stroke is the clot-busting drug IV tPA. There’s also a comprehensive stroke center (CSC) 20 minutes away, where in addition to IV tPA there is the option of mechanical thrombectomy (MT) and clot removal with a stent retriever. He asks which would be the better choice for his wife of 45 years.

Guidance for EMS

Transport destination dilemmas like this play out all over the United States daily. With stroke, the question of whether EMS should take additional time to bypass a closer PSC for a more-distant CSC with brain catheterization capabilities is currently a hot topic. Hospital, political and medical interests all weigh into these debates. At what point is the extra distance to a CSC too far to justify the extra transport time? Should all patients with possible stroke be transported to a CSC when available, or only some of them? What is the role and accuracy of field stroke severity scales such as RACE, FAST-ED, C-STAT or Stroke VAN in assisting with transport destination decisions? The correct answers to these questions will vary along with the availability of local stroke treatment resources and the efficiency of their systems. 

In 2013, the American Heart Association and American Stroke Association created guidelines that provide some direction for EMS regarding these issues. The AHA/ASA expert panel encouraged EMS systems to transport patients with suspected stroke to the highest level of stroke care within no more than an additional 15–20 minutes of transport time. So in the scenario above, the expert opinion is that your patient should be driven farther to get to the higher level of care. If we changed the scenario’s details by putting a non-stroke hospital within 7–8 minutes, a  PSC  within  20  minutes  and  no  CSCs within reasonable driving distance, then the recommendation would be to bypass the non-stroke facility in favor of the PSC. In addition, the experts encourage the use of air medical transport for stroke patients who have  no  resources  within  a  reasonable ground transport distance.¹ 

Advanced Treatments

The  2013  recommendations  to  bypass closer facilities in favor of CSCs were met with some controversy because in 2013 it had not yet been proven that MT offered better outcomes than IV tPA alone. However, in 2015  the  world  of  stroke care changed dramatically. Several well-conducted trials comparing IV tPA alone to IV tPA plus MT with a stent retriever finally gave the medical community proof of the superiority of interventional stroke care over IV tPA alone for emergent large-vessel occlusion (ELVO) strokes.^3–6 This prompted the AHA/ASA to publish a focused update to their stroke guidelines in 2015 encouraging healthcare systems to embrace these advanced treatments for eligible stroke patients.²

Theoretically, this evidence means EMS should  take  all  ELVO  patients  to  CSCs whenever they can be reached in a timely manner. In the case of small-vessel strokes where IV tPA may be all that’s needed, EMS can transport  those  patients  to  closer PSCs. The problem is, how do we in EMS know when a patient has a small vs. a large-vessel stroke? With this problem in mind, several stroke severity scales for use by EMS as potential triage tools have been developed. These include the RACE Scale, FAST-ED, Cincinnati Stroke Triage Assessment Tool (C-STAT), Stroke VAN and others. The merits of these scales will be discussed in the next issue, but suffice it to say, the ability to detect all  patients  in  need  of  comprehensive stroke care with these scales is limited with sensitivities as low as 55% and as high as 71%.⁷  

Use of these scales as EMS triage tools may be reasonable in systems with a scarcity of CSCs provided the PSCs are attuned to rapidly evaluating and transferring patients with missed ELVO. For systems with nearby CSCs, the AHA/ASA expert panel recommended patients be taken to the highest level of stroke care within an additional 15–20-minute transport time. This recommendation is regardless of initial severity estimates because, as we have seen with the limited detection ability of the prehospital stroke severity scales, some patients may initially appear to be eligible for a PSC but then deteriorate and need a CSC. 

Regionalization

For the authors’ EMS systems, a protocol was enacted to take all stroke patients regardless of severity score to a CSC and bypass the closer PSCs, provided we could meet the 20-minute transport guideline. Our internal unpublished CQI data found that the concept of regionalization worked as predicted. That is, like in the trauma system, treatment efficiency increased. Our data revealed that on average, travel to the CSC cost an additional seven minutes of driving time. However, since the CSCs became so efficient  at  treating  these patients, the 9-1-1-to-tPA time actually decreased on average by one minute. For patients requiring brain catheterization, this system saved on average 89 minutes from 9-1-1 to procedure.⁸ Since enacting this destination protocol, the time savings reflected above have become even more dramatic as the CSCs became even more efficient. In our systems, at least, the data supports following the AHA/ASA expert guidelines. But our systems are not unique in this regard. In one recent study, the median time to transfer a patient from initial arrival at a PSC to arrival at the CSC was over two hours.⁹ Potential delays in definitive care owing to secondary transport times from PSC to CSC highlight the critical importance of EMS taking the patient to the highest level of care within a reasonable distance whenever possible in the first instance.

So for our patient listed in the beginning of this article, where should EMS transport her? It is the author’s opinion that all stroke patients should bypass the primary stroke center whenever a CSC can be reached within the recommended 15- to 20-minute additional transport time. If that time frame is not achievable, then prehospital triage using a stroke severity scale is reasonable provided rapid secondary transport of patients with ELVO regularly occurs at the PSC. Aeromedical transport is indicated for systems with a scarcity of stroke treatment resources. For all scenarios, quality monitoring is absolutely necessary to ensure timely outcomes. While there can be many interests and forces involved when debating EMS transport decisions, for the sake of those we care for, let's make the patient’s best interest the only factor that matters. 

References

1. Higashida R, Alberts MJ, Alexander DN, et al. Interactions within stroke systems of care: A policy statement from the American Heart Association/American Stroke Association. Stroke, 2013 Oct; 44(10): 2,961–84.
2. Powers WJ, Derdeyn CP, Biller J, et al. 2015 American Heart Association/American Stroke Association Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke, 2015 Oct; 46(10): 3,020–35.
3. Berkhemer OA, Fransen PS, Beumer D, et al. A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med, 2015 Jan 1; 372(1): 11–20.
4. Goyal M, Demchuk AM, Menon BK, et al. Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med, 2015 Mar 12; 372(11): 1,019–30.
5. Campbell BC, Mitchell PJ, Kleinig TJ, et al. Endovascular therapy for ischemic stroke with perfusion-imaging selection. N Engl J Med, 2015 Mar 12; 372(11): 1,009–18.
6. Saver JL, Goyal M, Bonafe A, et al. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med, 2015 Jun 11; 372(24): 2,285–95.
7. Lima FO, Silva GS, Furie KL, et al. Field assessment stroke triage for emergency destination: A simple and accurate prehospital scale to detect large vessel occlusion strokes. Stroke, 2016 Aug; 47(8): 1,997–2002.
8. Palm Beach County Fire Rescue continuous quality improvement data, 2016 (unpublished).
9. Ng FC, Low E, Andrew E, et al. Deconstruction of interhospital transfer workflow in large vessel occlusion: Real-world data in the thrombectomy era. Stroke, 2017 Jul; 48(7): 1,976–9.

Kenneth A. Scheppke, MD, is dual board-certified in EMS and emergency medicine. He has been practicing emergency medicine for over 25 years and is the EMS medical director for six fire-rescue agencies in Palm Beach County, Fla., including Palm Beach Gardens, Palm Beach County, West Palm Beach, Boynton Beach, the Town of Palm Beach and Greenacres. He is also one of the EMS medical directors for the Broward Sheriff's Office. His agencies collectively serve a population of over two million people. For more than 18 years he has trained paramedics and EMTs as medical director for the Palm Beach State College EMS Academy. He is chair of the Palm Beach County EMS Medical Directors Association and for 15 years served as the assistant medical director of the JFK Medical Center emergency department in Atlantis, Fla. Reach him at kscheppke@pbcgov.org.
 
Paul E. Pepe, MD, MPH, is a professor of emergency medicine, internal medicine, surgery, pediatrics, public health and the Riggs Family Chair in Emergency Medicine, as well as the director of regional out-of-hospital care systems and event/disaster preparedness in the Office of Health System Affairs at the University of Texas Southwestern Medical Center (UTSW) in Dallas. He serves the City of Dallas as its director of medical emergency services for public safety, public health and homeland security. Reach him at paul.pepe@utsouthwestern.edu.