Reducing time delays and enhancing reperfusion eligibility related to stroke suspicion by the Emergency Medical Dispatch Centre: a registry-based observational study

Abstract

Background and aims: Research on the importance of the Emergency Medical Dispatch Centre (EMDC) role in reducing the time delays for patients with acute ischaemic stroke (AIS) is limited. This study aimed to analyse how Norwegian EMDCs' accurate suspicions can impact the clinical care times in this patient group.

Methods: We collected clinical care time metrics and acute reperfusion treatment data from the Norwegian Stroke Registry on patients with AIS in Western Norway who were evaluated by the EMDC and had an ambulance dispatched in 2021. In case a stroke was suspected by the EMDC, the dispatcher communicated their diagnosis suspicions to the ambulance personnel. Outcomes of interest were reperfusion treatment for AIS, prehospital and in-hospital time-to-treatment delays, and patient outcomes.

Results: Of the 1106 patients with AIS in our region, 771 (70 %) fulfilled the inclusion criteria. The EMDC suspected a stroke in 481 cases (62 %). Patients with suspected stroke experienced lower ambulance on-scene times (11 min vs 15 min; p=0.001), Emergency Medical Service prehospital times (40 min vs 49 min; p=0.021) and door-to-needle times (23 min vs 31 min; p=0.023). The EMDC stroke suspicion was associated with increased thrombolysis rates (OR 2.42 (95% CI 1.72 to 3.40)) after adjusting for age, sex, risk factors and functional status prior to the stroke event. The door-to-groin puncture times were lower for patients with a stroke suspicion who received endovascular treatment (65 min vs 85 min; p=0.004). No differences in the National Institutes of Health Stroke Scale score at the initial hospital arrival (4 vs 4; p=0.42) or in 90-day functional independence outcomes (rate of modified Rankin Scale score 0-2; 240 (61%) vs 160 (66%); p=0.24) were observed.

Conclusions: Accurate EMDC recognition of stroke suspicion alerts to ambulances were associated with a reduction in time until treatment and increased intravenous thrombolysis rates. A significant proportion of patients who had a stroke were not identified by the dispatcher. Improving dispatcher stroke assessment training, tools and knowledge may reduce time delays, thus improving patient outcomes.

Keywords: death; emergency care systems; stroke; triage.