Swiss guidelines for the prehospital phase in suspected acute stroke

Acute stroke treatment has advanced substantially over the last years. Important milestones constitute intravenous thrombolysis, endovascular therapy (EVT), and treatment of stroke patients in dedicated units (stroke units). At present in Switzerland there are 13 certified stroke units and 10 certified EVT-capable stroke centers. Emerging challenges for the prehospital pathways are that (i) acute stroke treatment remains very time sensitive, (ii) the time window for acute stroke treatment has opened up to 24 h in selected cases, and (iii) EVT is only available in stroke centers. The goal of the current guideline is to standardize the prehospital phase of patients with acute stroke for them to receive the optimal treatment without unnecessary delays. Different prehospital models exist. For patients with large vessel occlusion (LVO), the Drip and Ship model is the most commonly used in Switzerland. This model is challenged by the Mothership model where stroke patients with suspected LVO are directly transferred to the stroke center. This latter model is only effective if there is an accurate triage by paramedics, hence the patient may benefit from the right treatment in the right place, without loss of time. Although the Cincinnati Prehospital Stroke Scale is a well-established scale to detect acute stroke in the prehospital setting, it neglects nonmotor symptoms like visual impairment or severe vertigo. Therefore we suggest “acute occurrence of a focal neurological deficit” as the trigger to enter the acute stroke pathway. For the triage whether a patient has a LVO (yes/no), there are a number of scores published. Accuracy of these scores is borderline. Nevertheless, applying the Rapid Arterial Occlusion Evaluation score or a comparable score to recognize patients with LVO may help to speed up and triage prehospital pathways. Ultimately, the decision of which model to use in which stroke network will depend on local (e.g. geographical) characteristics.