Feature / Understanding stroke

Continuing our series helping to provide managers with a grounding in clinical activities, Steve Brown examines the stroke pathway

A stroke occurs when blood flow to part of the brain is interrupted. There are two main types of stroke. Ischaemic strokes result from a blood clot blocking an artery and account for about 85% of all strokes. Haemorrhagic strokes (the remaining 15%) are caused by a blood vessel bursting and bleeding into the brain. With brain cells dying at 1.9 million neurons per minute, the quality of outcome is massively related to the speed to treatment.

There are also so-called mini-strokes – or transient ischaemic attacks (TIAs) – where the stroke symptoms are short lived and resolve within 24 hours. Nevertheless, TIAs have the same etiology as ischaemic strokes and are often a warning of an imminent stroke. They therefore demand a similarly urgent response.

Typical immediate symptoms of stroke include facial weakness, arm weakness and speech problems. Time is of the essence in getting the patient assessed and treatment started. The NHS Act FAST campaign (pictured) has succeeded in raising public awareness of symptoms and how to respond.

Patients will typically be admitted to hospital via accident and emergency departments – usually following a 999 call. Best practice dictates that stroke patients, having been assessed in A&E, should be admitted into dedicated stroke units as quickly as possible.

Patients treated in a stroke unit rather than in a general ward have much improved outcomes – measured in reduced death rates, reduced levels of disability/dependency and reduced length of stay in hospital. But this insight has only been gained relatively recently – following a study of stroke unit care in the 1990s.

It has led to significant changes in the way stroke care is provided across the globe. In England, the value of dedicated stroke units was highlighted both in 2007’s national stroke strategy and the National Institute for Health and Clinical Excellence’s 2008 clinical guideline on stroke. As a result, there has been a growth in dedicated stroke units. The Royal College of Physicians’ biannual stroke audit last year reported for the first time that all hospitals treating acute stroke patients in England, Wales and Northern Ireland now have a stroke unit – described as a major achievement compared with a decade ago.

In fact in a stroke unit you may find different types of bed: those used solely for patients in the first 72 hours after stroke; those used solely for patients beyond 72 hours; and beds used for both the first 72 hours and beyond.

Stroke patients need to be taken to hospitals capable of providing urgent intensive diagnosis and treatment or hyper-acute stroke care. Hyper-acute units will have round-the-clock access to a stroke consultant and all the relevant support services. Ambulance service paramedics are trained to spot the symptoms of stroke and should transport patients to a unit providing hyper-acute care.

The key step on arrival at A&E following immediate clinical assessment is to undertake a brain scan (typically a CT scan but sometimes a more detailed MRI scan is needed). This identifies the type of stroke and helps establish if the patient is suitable for thrombolysis (the use of clot-busting drugs).

According to NICE guidelines, scans should be performed as soon as possible and within one hour for people with acute stroke where particular conditions are met. For example, if thrombolysis is considered a possible option or there is a known bleeding tendency, then scanning should be undertaken as a matter of extreme priority. In cases where immediate scanning is not indicated, scanning should still be undertaken within a maximum of 24 hours.

Thrombolysis is another relatively recent development with the drug known as alteplase only licensed for use in treating stroke in the UK in 2002. The benefits of administering the drug – leading to the breakdown of the clot and restoration of blood flow to the brain – are widely acknowledged, but the drug needs to be administered within a few hours of the onset of symptoms. This was a three-hour window originally, but further studies have shown benefits can be realised up to 4.5 hours after symptoms emerge. This was reflected in updated technology appraisal guidance from NICE in September 2012. 

‘Thrombolysis is not without risk,’ says Pippa Tyrrell, professor of  stroke medicine at Manchester University and honorary consultant stroke physician at Salford Royal NHS Foundation Trust. ‘It can’t just be done by anyone and the patient needs close monitoring afterwards, so there needs to be good awareness of the possible complications.’

Professor Tyrrell says US experience shows the importance of adhering to protocols and she argues that, where geography allows, greater specialisation characterised by the models in London and Greater Manchester are the way forward (see box page 19). ‘How can you possibly deliver [optimum care] in a district general hospital that is seeing one stroke patient a day for a population of 200,000 with 24/7 access to scanning, radiographers and stroke consultants?’

Need for reform

The RCP audit last year underlined the need for reform, suggesting that ‘if all 437 stroke physicians on a thrombolysis rota were spread evenly across the 153 hospitals [sites delivering thrombolysis], there would be insufficient numbers of stroke physicians to run safe and legitimate rotas in all hospitals’. To address this would require a reduction in the number of hospitals delivering hyper-acute stroke care, greater uptake of telemedicine, or the training of other specialists to take part in rotas.

Thrombolysis involves an injection, then a one-hour infusion usually undertaken in A&E. The RCP 2012 audit report suggests just under a third of hospitals are thrombolysing 10% of patients or more. According to Professor Tyrrell, even the very best specialist centres will only be achieving levels of about 20%.

The key determinant is the time between onset of symptoms and administration of the drug. However, in many cases it will not be clear what time has elapsed. For example, the patient may have woken up with stroke symptoms, making the start time uncertain and ruling out thrombolysis.

For ischaemic patients where thrombolysis is not appropriate, patients will typically be given aspirin as a common anti-platelet medicine to inhibit future clotting. Many will need significant support. Large numbers of stroke patients have difficulty swallowing and pneumonia can be a related complication. Early therapy and specific support from specialist nursing staff – for example, sitting patients up rather than lying down – can have a big impact on outcomes.

Patients with haemorrhagic strokes also need close monitoring. They may be extremely unwell with impaired conscious level. They may also need high dependency or intensive care unit level support including ventilation, and sometimes neurosurgical intervention.

The acute phase of stroke treatment will extend over the first 24 hours and up to as much as seven days, but is more typically complete within three days. Recovery and rehabilitation starts in hospital but continues in the community, with early supported discharge often seen as the best option.

Transient ischaemic attacks have earned the name ‘mini-strokes’ for good reason. They share the same causes and symptoms as ischaemic strokes. The only difference is that the symptoms last a short time, often only a few minutes and are fully resolved within 24 hours. However, TIAs need to be treated seriously and urgently. According to the NHS Choices website, without treatment, there is a one in 10 chance a patient suffering from a TIA will have a full stroke within four weeks. Treatment can greatly reduce this risk.

High-risk TIAs have to be seen and investigated within 24 hours according to guidelines. Possible interventions include surgery – for example, a carotid endarterectomy could be performed to remove part of a damaged carotid artery along with any blockage that has built up from fatty deposits – a process known as atherosclerosis.

Advice about exercise, diet and smoking is given together with antiplatelet drugs (such as aspirin or clopidogrel) and anticoagulation for patients with a heart rhythm disturbance (atrial fibrillation). Often patients need statins for hyperlipidaemia and blood tests to exclude diabetes. Many trusts have a rapid access TIA  clinic that runs alongside the stroke unit to ensure patients receive an accurate diagnosis, appropriate imaging, advice and medication together with referral for carotid surgery, where appropriate, within the time period specified in the guideline.