# Activation of Emergency Department Stroke Protocol by Emergency Medical Services: A Retrospective Cross-Sectional Study

## TL;DR

EMSs often over-activate stroke protocols, but they successfully identify most stroke patients, and better communication can improve efficiency.

## Contribution

Validates EMS activation of ED stroke protocols in Israel and suggests improvements to reduce over-activation while maintaining patient safety.

## Key findings

- EMSs had a 100% negative predictive value, meaning no stroke patients were missed.
- Only 20% of stroke protocol activations by EMSs were confirmed as actual strokes.
- Communication improvements could reduce unnecessary resource use and treatment delays.

## Abstract

Background/Objectives: Early diagnosis of stroke is crucial for effective treatment with tissue plasminogen activator (tPA) and endovascular thrombectomy. Emergency medical services (EMSs) screening and the early activation of emergency department (ED) stroke protocols reduce treatment times and improve patient outcomes. This study aims to validate ED stroke protocol activation by EMSs in a large stroke center. Methods: This retrospective cross-sectional study was conducted at Magen David Adom and Shamir Medical Center between 1 January 2019 and 31 December 2019. Data were categorized into patients suspected by EMSs of having a stroke and those not suspected by EMSs but diagnosed as having a stroke in the ED. The primary outcome was the accuracy of EMSs in activating ED stroke protocols. Results: In this study, there were 23,061 patients, of which 11,841 (51.9%) were females. The mean age was 61.4 (SD = 22.72) years old. EMSs suspected 743 (3.22%) patients were having a stroke. In 587 (79%), EMSs activated ED stroke protocols. There were 88 cases where strokes were diagnosed in the ED when EMSs did not suspect a stroke. The overall EMSs negative predictive value (NPV) was 100% while the positive predictive value (PPV) was 20%. Conclusions: While Israeli EMSs over-activate the ED stroke protocol, stroke patients are almost never missed, achieving the goal of prehospital stroke screening. To prevent resource waste, all involved teams should be notified, and the actual activation of the stroke protocol should be carried out by an ED physician upon patient arrival. Communication between all levels regarding stroke protocol should also be increased to decrease the time to treatment.