Cortical symptoms described in emergency calls for patients with suspected large vessel occlusion: a descriptive analysis of 157 emergency calls

Abstract

Background: Emergency medical dispatchers typically use the dispatch code for suspected stroke when the caller brings up one or more symptoms from the face-arm-speech triad. Paramedics and emergency department physicians are trained to suspect large vessel occlusion stroke when the stroke patient presents with hemiparesis and cortical symptoms: neglect, aphasia, and conjugate eye deviation (CED). We hypothesized that these symptoms could be evident in the emergency call. In this study, we aimed to describe common symptoms mentioned in the emergency calls for paramedic-suspected thrombectomy candidates. Secondly, we wanted to explore how the question about CED arises in the Finnish suspected stroke dispatch protocol. Our third aim was to find out if the symptoms brought up in suspected stroke and non-stroke dispatches differed from each other.

Methods: This was a retrospective study with a descriptive analysis of emergency calls for patients with paramedic-suspected large vessel occlusion stroke. We listened to the emergency calls for 157 patients transported to Tampere University Hospital, a Finnish comprehensive stroke centre. Two researchers listened for symptoms brought up in these calls and filled out a pre-planned case report form.

Results: Speech disturbance was the most common symptom brought up in 125 (80%) calls. This was typically described as an inability to speak any words (n = 65, 52% of calls with speech disturbance). Other common symptoms were falling down (n = 63, 40%) and facial asymmetry (n = 41, 26%). Suspicion of stroke was mentioned by 44 (28%) callers. When the caller mentioned unconsciousness the emergency dispatcher tended to use a non-stroke dispatch code. The dispatchers adhered poorly to the protocol and asked about CED in only 57% of suspected stroke dispatches. We found CED in 12 emergency calls and ten of these patients were diagnosed with large vessel occlusion.

Conclusion: In cases where paramedics suspected large vessel occlusion stroke, typical stroke symptoms were described during the emergency call. Speech disturbance was typically described as inability to say anything. It is possible to further develop suspected stroke dispatch protocols to recognize thrombectomy candidates from ischemic cortical signs such as global aphasia and CED.

Keywords: Emergency medical dispatch; Emergency medical services; Large vessel occlusion stroke.

Fig. 1

Map of the study area with a strengthened black line encircling Pirkanmaa hospital district, a square pattern indicating the hospital districts with primary stroke centres referring patients to Tampere University Hospital and solid grey areas representing the municipalities from which patients with suspected large vessel occlusion are transported straight to Tampere University Hospital

Fig. 2

Patient flow. EMS, emergency medical services; CED, conjugate eye deviation; LVO, large vessel occlusion; PSC, primary stroke centre

Fig. 3

Proportion (with 95% confidence interval) most common symptoms mentioned in the emergency calls