Strokes: progressive stroke pathway

9. Hyperacute Stroke Treatment

For some people, treatment of stroke within the first few hours can include treatments such as thrombolysis and thrombectomy. These are aimed at unblocking the artery. Both have the potential to greatly reduce the brain damage caused, and thus improve functional outcomes and probably survival.

Early blood pressure lowering, in some cases of intracerebral haemorrhage (ICH) may be beneficial and continues to be researched.

The earlier these treatments are given, the more chance the person will have of an improved outcome. Therefore, stroke services need to be configured to minimise any delays and maximise the proportion of patients suitable.

Patients receiving these treatments require more intensive observation and monitoring to minimise risks and identify complications early when they can be most effectively treated. Therefore, post intervention, they should be cared for in a stroke unit enabling close, non-invasive monitoring of physiological parameters to detect the early complications of treatment and of their stroke.

Assessment to determine eligibility for these treatments is outlined in Section 7.2: Assessment of eligibility for hyperacute treatments. This section will therefore focus on the logistics of delivering these treatments as quickly as possible once a patient has been identified as eligible.

9.1 Intravenous thrombolysis

Outcomes from ischaemic stroke treated with thrombolysis are time critical and can be improved by minimising the delay from stroke onset to thrombolysis treatment. There are a number of performance measures within the Scottish Stroke Care Audit relating to the delivery of thrombolysis, and performance measures for thrombectomy are in development.

Thrombolysis is carried out at 22 ASCs and 3 CSCs in Scotland. There is variation in the proportions of patients receiving thrombolysis and variation in door-to-needle time between hospitals.

In most hospitals offering thrombolysis the door-to-needle times are much shorter during normal working hours than at other times. However, in services where a stroke nurse is involved in "pulling'' the patient through the pathway, or where specialist stroke doctors are available in person out of hours, door-to-needle times tend to be shorter overall, and the difference between in and out of hours is minimised. This reinforces the importance of adequate stroke specific staffing, including the important role played by stroke nurses.

9.2 Thrombectomy

The most severe 10-20% of acute ischaemic strokes are due to a large vessel occlusion (LVO). Restoring blood flow with early thrombectomy, sometimes referred to as clot retrieval, significantly reduces dependency^,. In some cases, thrombolysis is given prior to the thrombectomy procedure.

Approximately 800 cases per annum in Scotland, 10% of all stroke presentations, could be treated by a 24/7, Scotland wide, thrombectomy service.

Geographical modelling recommends three CSCs (sometimes called Thrombectomy hubs) serving 22 ASCs (sometimes referred to as spoke hospitals) where patients are first taken to their nearest ASC to be diagnosed, scanned, receive thrombolysis if appropriate, and then be transferred to a CSC for thrombectomy. This is known as the 'drip and ship model'.

There is a planned incremental development of services across the three CSCs (Queen Elizabeth University Hospital, Glasgow, Royal Infirmary of Edinburgh and Ninewells Hospital, Dundee) aiming for 24/7 availability across Scotland by 2023.

It will be important, as the service develops, that monitoring of referrals to the service is followed closely and accounted for in future service planning. This is because the number of people eligible for thrombectomy may increase due to advances in imaging, technology and research.

9.2.1 Transfer from ASC to CSC for thrombectomy

The transfer of patients between hospitals is an aspect of the thrombectomy pathway which can introduce delays to this time critical treatment. Therefore, it is important that safe, efficient and timely transfers take place.

An important aspect of transfer is ensuring agreed and robust communication processes and modalities for discussing cases between ASC, CSCs and the interventional neuro radiologists (INRs) /interventional radiologists (IRs) who will be carrying out the procedure. It is vital that adequate infrastructure is in place for effective and reliable communications between all relevant teams and health boards.

Utilisation of electronic devices (using 4G/5G), capable of real time information sharing between the thrombectomy nurse escort (based at the ASC hospital), the ASC and CSC stroke physicians and INR/IR which integrate with patients' electronic health records would improve workflows and patient safety. Back-up systems (such as airwave radio systems) should be in place for when primary modes of communication fail or become unreliable due to connectivity or unplanned downtime.

The use of a mobile communication platform is currently being explored by the Thrombectomy Advisory Group (TAG)^[1].

9.2.2 Repatriation

People who receive thrombectomy initially require intensive monitoring and support after the intervention in a stroke unit in the CSC until they are deemed to require less intensive care and are suitable for transfer to a stroke unit in the ASC. This is known as repatriation. Repatriation enables patients to receive as much of their care near their own home as possible. Prompt repatriation is vital to maintain flow and for CSCs to continue to take incoming referrals from ASCs.

It is important that there are shared protocols between CSCs, ASCs and the SAS for the delivery of agreed, safe and efficient repatriation. Decisions around repatriation after thrombectomy should be guided by the readiness for repatriation checklist, developed by TAG.

9.2.3 Interventional neuroradiology

Imaginative and flexible workforce solutions will be essential in a globally competitive employment market due to a shortage of specialist trained INRs. Incentivising rotas and job plans may be a partial solution if Scotland is to be an attractive workplace for specialist trained staff. Features of a sustainable interventional neuroradiology/radiology service for thrombectomy will include^,,:

• A volume of work at CSCs that satisfies the agreed numbers for maintaining competency and training - training may involve remote mentoring and simulation technology-based teaching.
• Credentialing, supported by interventional neuroradiologists (INRs), may be necessary to train sufficient operators to populate 24/7 rotas across Scotland and enable cover of non- stroke INR work e.g., aneurysm coiling.
• Workforce planning futureproofed for the anticipated increase in workload once a service has commenced and the inevitable effect of extending time windows for intervention as advancements in therapies emerge.
• Cognisance that 60% of potential cases will present out of hours - work patterns, job plans and rotas will need to reflect this in order to provide equity of access and avoid the "weekend effect".
• Adoption of cutting-edge technological innovation including advancements in AI and neurointerventional robotic solutions.
• Opportunities to participate in research and teaching.

9.3 Management of intracerebral haemorrhage (ICH)

Strokes due to intracerebral haemorrhage (ICH) represented 12% of stroke admissions in Scotland in 2019. Mortality rates and disability remain disproportionately high within this group worldwide.

A progressive stroke service should aim to improve outcomes for this group of patients. Hyperacute stroke services for ICH should include^,,,:

• Expert supportive care on a stroke unit, aiming for consistent and optimal care and close observation for signs of deterioration.
• Care that reflects emerging best evidence for reducing secondary brain injury
• Consideration of the adoption of care bundles to help consistency and reduce variation by standardising processes of care.
• Incorporate evidence-based interventions where available.
• Early communication with local or regional neurosurgical teams where the patient is at risk of developing hydrocephalus or other complications amenable to neurosurgical intervention.
• Rapid anticoagulant reversal protocols responsive to emerging evidence as up to 20% of ICH cases occur in patients taking anticoagulant medication.
• If required, the delivery of appropriate end of life care, consistent with the approach outlined in Section 9.3: End of Life Care, and the avoidance of harm and unintended limitations of care by ensuring timely senior level decision making regarding advanced care planning.

9.4 Recommendations

1. All patients eligible for thrombolysis should receive the intervention with the minimum delay. Therefore, there should be a sustained drive to improve door-to-needle times across Scotland.

2. Telestroke networks should be developed to support hospitals in achieving optimal thrombolysis treatment numbers and door-to-needle times.

3. There should be time efficient pathways and agreed processes for thrombectomy in place at all ASCs and CSCs to optimise patient outcomes and limit patient exclusions in those with ischaemic stroke due to LVO.

4. The provision of mobile communication platforms and adequate mobile technology will enable stroke physicians and INR/IRs to interpret hyperacute imaging remotely.

5. There should be nationally agreed pathway documentation, in digital and paper format, to facilitate movement of patients between NHS Boards and regions and to reduce duplication of imaging and investigations.

6. For patients referred for thrombectomy the door in, door out time in ASCs should be minimised.

7. Patients eligible for thrombectomy should be transferred to the CSC via the quickest and safest transport means available as determined by SAS.

8. Staff carrying out thrombectomies unsupervised should have completed recognised training and should perform a sufficient number of interventional procedures per annum to maintain their competencies.

9. The door-to-puncture time at thrombectomy hubs should be as short as is safely possible.

10. There should be agreed and sustainable rotas for anaesthetic staff, INRs/IRs, stroke physicians and theatre staff supporting the thrombectomy service.

11. There should be agreed, safe and efficient repatriation protocols in place between the CSCs and ASCs to ensure optimal patient flow.

12. There should be continuous review of the thrombectomy service model, processes of care and referral criteria as the evidence base grows. Regular multi-professional governance meetings should take place across Scotland with the intent of optimising learning for all involved in the process and embracing a culture of quality improvement.

13. Stroke services should have protocols for the monitoring, referral and urgent transfer of patients to regional neurosurgical centres.

14. A focus should be placed on improving outcomes for people with intracerebral haemorrhage. This may be achieved by the adoption of care bundles to help consistency and reduce variation by standardising processes of care.