We identified references for this Review by searching PubMed for articles published between Jan 1, 1980, and Dec 31, 2012, that contained the terms “prehospital” and “stroke”; “stroke management”; “emergency medical service” and “stroke”; or “thrombolysis” and “stroke”. We also identified articles through searches of reference lists and our own files. We reviewed only articles published in English, focusing on originality and relevance to the broad scope of this Review.
ReviewStreamlining of prehospital stroke management: the golden hour
Introduction
Stroke is the most frequent cause of permanent disability in adults and one of the most frequent causes of death.1, 2 In addition to substantial individual suffering, stroke results in enormous costs to society.3, 4 Intravenous thrombolysis with alteplase is an effective treatment for acute ischaemic stroke, as shown in several randomised and placebo-controlled multicentre studies.5, 6, 7, 8, 9 The approved time window for stroke treatment after the onset of symptoms ranges from 3·0 h to 4·5 h in various countries. However, even within this time window, the benefit of treatment strongly decreases as time passes (the so-called time-is-brain concept).10, 11 The same time-sensitivity can be expected with novel endovascular treatment options.12
The number needed to treat with intravenous alteplase for a good outcome, defined as a modified Rankin score of 0–1, has been calculated at 4·5 if treatment is initiated within 1·5 h after the onset of symptoms.7, 13 This number doubles to 9 if treatment is initiated between 1·5 h and 3·0 h after symptom onset, and reaches 14·1 if treatment is delivered between 3·0 h and 4·5 h after onset7 (smaller numbers needed to treat might have been achieved if the modified Rankin scale had been used in its original full seven-level version). For every minute a large-vessel stroke goes untreated, an estimated maximum of 1·9 million neurons and 14 billion synapses are potentially lost, suggesting that even small differences in time to reperfusion could produce clinically relevant differences.14
In this Review of prehospital stroke management we emphasise that all links in the prehospital stroke rescue chain must be optimised so that in the future more than a small minority of patients can profit from time-sensitive acute stroke therapy.
Section snippets
Prehospital stroke management to reduce treatment delay
Before alteplase can be delivered, a complex diagnostic work-up (including neurological examination, imaging, and laboratory analysis) is necessary for exclusion of haemorrhage, diseases mimicking stroke, and other contraindications. This work-up consumes crucial time, often precluding treatment within the approved therapeutic window. Although in some experienced specialised centres administration of intravenous altepase to 20–30% of patients with ischaemic stroke within 3 h is possible,15, 16
Delay in seeking medical attention
Delay in seeking medical attention after the onset of stroke symptoms is an important reason for the underuse of thrombolytic therapies.36, 37, 38, 39, 40 Reported delays in seeking treatment range from 38 min to 4 h.41, 42, 43, 44, 45 Between 24% and 54% of patients with stroke do not call for help within 1 h,41, 45, 46 and many do not seek medical care at all. Reports suggest that only 38–65% of patients use EMS.23, 27
Much evidence suggests, however, that the use of EMS is a crucial variable
Educational programmes for EMS personnel
A great potential for optimisation of stroke management lies with the EMS. The structures of EMS are highly variable between countries and even between states or areas of individual countries.90, 91 Therefore, generalisation of the results of studies in one setting to other settings is difficult. Fairly good evidence already exists for several factors, such as the effectiveness of educational programmes for EMS personnel, the use of instruments for symptom recognition, priority transport to
Use of ambulances as clinical laboratories for research on stroke treatments
Interest is increasing in diagnostic and therapeutic approaches for use in the prehospital phase of stroke management; such approaches might allow responders to reach the patient at a time when the chance of rescuing ischaemic brain tissue is highest. Several ambulance-based studies have been done or are underway on topics including diagnostic measures such as ultrasound140 or electrical impedance tomography for detection of haemorrhage141, 142 and therapeutic approaches such as neuroprotection
Conclusion
This Review clearly shows that every link in the prehospital stroke rescue chain matters and must be further studied for potential improvements. Further research is needed to establish the most effective public awareness programmes that can affect behaviour in an actual emergency situation. Guideline-recommended measures, such as ongoing EMS education, use of stroke recognition scales, triage to hospitals with stroke expertise, and advance notification to the receiving hospitals, should be
Search strategy and selection criteria
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