Impact of mobile stroke units

Abstract

Since its first introduction in clinical practice in 2008, the concept of mobile stroke unit enabling prehospital stroke treatment has rapidly expanded worldwide. This review summarises current knowledge in this young field of stroke research, discussing topics such as benefits in reduction of delay before treatment, vascular imaging-based triage of patients with large-vessel occlusion in the field, differential blood pressure management or prehospital antagonisation of anticoagulants. However, before mobile stroke units can become routine, several questions remain to be answered. Current research, therefore, focuses on safety, long-term medical benefit, best setting and cost-efficiency as crucial determinants for the sustainability of this novel strategy of acute stroke management.

Keywords: stroke.

Figure 1

Prehospital unenhanced CT scans (A) and CT angiography images (B) of a patient who had an acute stroke caused by large-vessel occlusion of the left middle cerebral artery (arrow), enabling a triage decision to transport a patient to a CSC for intra-arterial therapy. Prehospital unenhanced CT scanning (C) and CT angiography images (D) of a patient with a hypertensive intracerebral haemorrhage in the basal ganglia with a ‘spot sign’ (arrow), indicating ongoing bleeding and enabling a triage decision to transport to a CSC for neurointensive care. CSC, comprehensive stroke centre.

Figure 2

Gains in time from emergency call (left) or symptom onset (right) to treatment or treatment decision conferred by use of mobile stroke units (MSUs) in comparison with standard treatment in various controlled studies. The referring studies were published by (1) Taqui et al, (2) Ebinger et al, (3) Walter et al, (4) Shownkeen et al, (5) Kummer et al, (6) Grotta et al and (7) Ebinger et al. tPA, tissue plasminogen activator.

Figure 3

Rates of therapy decisions for or against thrombolysis (end of all required diagnostic work-up, including laboratory and imaging studies) during the golden hour for patients treated in a mobile stroke unit (MSU) and those given standard treatment in the first randomised trial.

Figure 4

In conventional stroke management, patients are transferred to the nearest stroke centre, which is usually a PSC. In case of presence of LVO, patients are, after thrombolysis, secondarily transferred to a CSC for intra-arterial therapy (‘drip-and-ship concept’) (A). In stroke management with a mobile stroke unit, LVO is diagnosed by vascular imaging on scene, enabling accurate triage decisions with regard to transport to the appropriate target hospital. Secondary interhospital transfers are no longer required (B). CSC, comprehensive stroke centre; CT-A, CT angiography; LVO, large-vessel occlusion; PSC, primary stroke centre; tPA, tissue plasminogen activator.

Figure 5

World map of mobile stroke unit projects.