A novel emergency medical services protocol to improve treatment time for large vessel occlusion strokes.

Nancy Glober,Sarah Persaud,Michael Supples,David Kim,Dan O’Donnell,Mark Liao,Andreia Alexander,Michele Glidden,Christopher Tainter,Malaz Boustani,Karen M Doyle

doi:10.1371/journal.pone.0264539

Abstract

In many systems, patients with large vessel occlusion (LVO) strokes experience delays in transport to thrombectomy-capable centers. This pilot study examined use of a novel emergency medical services (EMS) protocol to expedite transfer of patients with LVOs to a comprehensive stroke center (CSC). From October 1, 2020 to February 22, 2021, Indianapolis EMS piloted a protocol, in which paramedics, after transporting a patient with a possible stroke remained at the patient's bedside until released by the emergency department or neurology physician. In patients with possible LVO, EMS providers remained at the bedside until the clinical assessment and CT angiography (CTA) were complete. If indicated, the paramedics at bedside transferred the patient, via the same ambulance, to a nearby thrombectomy-capable CSC with which an automatic transfer agreement had been arranged. This five-month mixed methods study included case-control assessment of use of the protocol, number of transfers, safety during transport, and time saved in transfer compared to emergent transfers via conventional interfacility transfer agencies. In qualitative analysis EMS providers, and ED physicians and neurologists at both sending and receiving institutions, completed e-mail surveys on the process, and offered suggestions for process improvement. Responses were coded with an inductive content analysis approach. The protocol was used 42 times during the study period; four patients were found to have LVOs and were transferred to the CSC. There were no adverse events. Median time from decision-to-transfer to arrival at the CSC was 27.5 minutes (IQR 24.5-29.0), compared to 314.5 minutes (IQR 204.0-459.3) for acute non-stroke transfers during the same period. Major themes of provider impressions included: incomplete awareness of the protocol, smooth process, challenges when a stroke alert was activated after EMS left the hospital, greater involvement of EMS in patient care, and comments on communication and efficiency. This pilot study demonstrated the feasibility, safety, and efficiency of a novel approach to expedite endovascular therapy for patients with LVOs.

Highlights

In the United States, approximately 795,000 people sustain a stroke each year, which equates to one stroke every 40 seconds, and a death from stroke every four minutes.[1]
Minimizing time to endovascular thrombectomy (EVT) is critical to achieving these superior outcomes. 91% of large vessel occlusions (LVOs) patients achieved functional independence at 90 days if EVT was performed within 150 minutes of symptom onset, but the probability of functional independence decreased by 10% over the hour, and by 20% over each subsequent hour [8]
We reviewed prehospital and in-hospital charts of all patients transferred under the pilot protocol for adverse events, including patient deterioration secondary to transfer by non-critical care trained emergency medical services (EMS) providers, motor vehicle collisions, and intracranial hemorrhage

Summary

Introduction

In the United States, approximately 795,000 people sustain a stroke each year, which equates to one stroke every 40 seconds, and a death from stroke every four minutes.[1]. Since 2015, the advent of endovascular thrombectomy (EVT) has significantly improved outcomes in patients with LVOs [5]. The five initial randomized control trials investigating EVT demonstrated a number needed to treat of 2.6 to reduce a patient’s 90-day modified Rankin score (mRS) by 1 point, compared to conventional thrombolysis [5]. Minimizing time to EVT is critical to achieving these superior outcomes. 91% of LVO patients achieved functional independence at 90 days (mRS = 0–2) if EVT was performed within 150 minutes of symptom onset, but the probability of functional independence decreased by 10% over the hour, and by 20% over each subsequent hour [8]. Every 30-minute increase in time-to-EVT reduced the probability of functional independence by 8.3% [9]

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