Percutaneous Stroke Intervention (PSI) Referral Guidelines

Quick links

• Endovascular thrombectomy (clot retrieval) information for whānau

• Paediatric anaesthetic stroke pathway (Starship only)

Eligibility criteria

• Potentially disabling neurological deficits

• PedNIHSS > 4

• Clearly defined time of symptom onset. This is the time last known well for patients with 'wake up' or unwitnessed strokes.

• Previously independent (mRS 0,1 or 2) within context of age/development

• Evidence of arterial occlusion in:

  • Carotid artery termination

  • M1 segment middle cerebral artery or all M2 branches

  • Basilar artery

  • Selected patients with single M1 or posterior cerebral artery P1 branch occlusion with favourable clinical and imaging features

And

• Groin puncture can commence within

  • 6 hours for patients with internal carotid artery (ICA) or middle cerebral artery (MCA) M1 occlusion

  • 6 - 24 hours in highly selected patients with internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion. This requires additional imaging with CT perfusion (or MR diffusion-weighted/perfusion imaging).
    
    The accepting neurologist and neurointerventionist will take into account the following evidence when deciding whether or not to transfer the patient:
    

    DEFUSE 3 criteria for patients where groin puncture can occur within 6 - 16 hours
    o	NIHSS > 6
    o	Infarct core < 70 mL on CT perfusion-CBF
    o	Ratio of ischemic tissue to infarct core at least 1.8
    o	Penumbral tissue > 15 mL
    DAWN criteria for patients where groin puncture can occur within 6-24 hours
    o	pedNIHSS > 10 and infarct volume < 31 mL on DWI or CT perfusion-CBF
    o	pedNIHSS > 20 and infarct volume < 51 mL on DWI or CT perfusion-CBF

    CT perfusion scans (or MRI perfusion scans) are to be obtained at the referring hospital. Patients will NOT be transferred purely for perfusion imaging at Auckland City Hospital, as only a minority of patients presenting in the 6-24 hr window will meet the treatment criteria and transfer of unselected patients has potential for harm.
    
    The need to transfer a patient for paediatric neurology or PICU care is independent of re-perfusion treatment and is assessed on a case by case basis.
    
    With respect to transfer primarily for clot retrieval, the accepting team will take into account likely transfer delays when interpreting the clinical information and imaging results, and making a final decision on whether to accept a patient. In patients transferred by helicopter, the mean time from symptom onset to arrival at Auckland City Hospital is greater than 6 hours, and from CT scanning at the referring hospital to arrival at Auckland City Hospital is greater than 4 hours. These delays mean that the accepting team will require CTP in the majority of patients being transferred by helicopter as most will arrive beyond 6 hours.
    
    There may be individual patient scenarios that challenge these guidelines. If so, the accepting neurologist is encouraged to discuss with a stroke subspecialist and always with the on-call neurointerventionalist.

  • 12 hours for patients with basilar artery occlusion. Basilar artery occlusion patients may be considered between 12 and 24 hours if there has been step-wise deterioration from symptom onset (eg vertigo for 12 hours and then 'locked in' for 2 hours) and/or there is no extensive posterior circulation infarction on imaging.

Exclusion criteria

• Evidence of intracranial haemorrhage

• Large infarct core in those presenting within six hours as determined by non-contrast CT scan infarction

• Patients with cervical artery dissection or occlusion may be considered for treatment on a case-by-case basis.

Treatment decision co-ordination processes

It is critical to minimise delays when making decisions on whether to proceed with PSI. This is facilitated by clear and co-ordinated team decision making process.

Many clot retrieval patients will also be eligible for IV thrombolysis under the standard thrombolysis criteria. In such patients the PSI pathway is activated in conjunction with thrombolysis therapy i.e. do not wait until the infusion is complete before deciding whether to proceed with clot retrieval.

Role of non-PSI centre paediatrician/neurologist

• Review the patient and in discussion with accepting neurologist (+/- PICU as needed), ensure they meet PSI treatment inclusion/exclusion criteria.*

• Ensure the immediate electronic transfer of all images to the PSI centre via PACS. This should be done prior to contacting the PSI centre neurologist.

• Telephone the receiving neurologist to discuss eligibility. Ask the operator for the 'on call paediatric neurologist'.

• Arrange ambulance/helicopter transport once patient accepted

• Send/transfer the appropriate clinical documentation related to the patient

• Explain the transfer and treatment process to patient/whānau. The patient information hand-out is available via the Starship Stroke Guideline.

• Explain to the patient/family that the final decision on suitability for clot retrieval will be made on arrival at the PSI centre.

• Telephone the receiving paediatric neurologist if there is any change in clinical state

• Arrange nurse escort if indicated (see inter-hospital transport considerations below)

*Patients that are to be transferred by helicopter should be reviewed in person or via video (telemedicine) by the referring physician. This is necessary to ensure patient safety and prevent futile helicopter transfers and call-outs of the PSI team

Patients will be received in CED resus/PICU. They will be met and rapidly reviewed by the on-call neurologist on arrival and PedNIHSS reassessed. If considered eligible for PSI the patient will then be transferred directly to the angiography suite. The PSI team is therefore reliant on both the referring physician's opinion that clot retrieval is appropriate and rapid reassessment on arrival.

Role of the PSI centre neurologist

• Liaise with the referring paediatrician or ED physician, PICU and neurointerventionalist to determine suitability for transfer taking into account clinical features and anticipated transfer time.

• Activate the PSI team to ensure patient is met on arrival in the emergency department/PICU.

• Decide if PSI is clinically appropriate when the patient arrives in conjunction with neurointerventionalist.

• Be responsible for overall patient management

Role of the PSI centre neurointerventionalist

• Liaise with the receiving neurologist to determine suitability for transfer

• Review imaging to assess suitability for PSI

• Coordinate the neurointerventional and paediatric anaesthetic team. Note: if cardiac patient will need cardiac anaesthetist. (see Paediatric anaesthetic stroke pathway (Starship only))

• Make the final decision regarding suitability for PSI once the neurologist has decided that this remains clinically appropriate upon arrival.

• Consent for the procedure

• Perform and document the procedure

• Provide clinical advice about post-procedure complications if available

Inter-hospital transport considerations

Inter-hospital transfers are time critical and must occur without delay.

• The patient will be transported to the PSI centre by ambulance, child flight or helicopter, depending on the distance between hospitals, the availability of helicopters and weather.

• All practical steps should be taken to ensure that the transfer is seamless and that delays are minimised. For example, the remaining dose of thrombolytic agent should be prepared and connected without the need for syringe changes.

• PSI centre staff should be notified of the expected time of arrival and updated if this changes en route

• If the patient is being transferred by road ambulance, an appropriately trained person must accompany the patient. This will usually be a nurse. The closest appropriate ambulance must be used and the transport undertaken as an urgent ('under lights') transfer. It is expected that patients will be in a helicopter within 60 minutes of acceptance by the PSI centre.

• If the patient is being transferred by helicopter, an appropriately trained person must accompany the patient and this can be a nurse or an Intensive Care Paramedic. The closest appropriate helicopter must be used and the transfer undertaken as an urgent transfer. It is expected that patients will be in a helicopter within 60 minutes of acceptance by the PSI centre.

• The patient may require an inter-hospital transfer team comprising a doctor and nurse, for example if the patient is ventilated. However, using an inter-hospital transfer team creates delay and should only occur when this is necessary.

• Ventilated patients. In general, ICA/MCA occlusion patients who require ventilatory support will not be accepted as PSI is likely to be futile. Exceptions include those patients intubated because of agitation or prolonged seizures.

  • Basilar occlusion patients may require ventilation and will be accepted

  • The PSI centre neurologist must discuss and clear ventilated patients with the PICU team prior to transfer, and if a patient is intubated during the transfer.

Management at the PSI centre emergency department/PICU

• The emergency department and on-call anaesthesia service should be pre-notified with the patient's name, date of birth, stroke onset time and estimated time of arrival, as well as brief clinical presentation, comorbidities and medications.

• The PSI team (neurologist, neurointerventionalist, anaesthetist) should meet the patient on arrival and quickly determine whether the patient requires cardiorespiratory stabilisation and if the procedure is still appropriate.

• In patients transferred from other centres, imaging should not be repeated unless there has been a significant change in clinical status or more than two hours has passed since the last imaging study.

• The patient is then transferred directly to the angiography suite on the ambulance trolley.

Consent

Consent should be attained by the neurointerventionalist. Consent for ECR should include all of the following: general anaesthetic, cerebral angiography +/- endovascular clot retrieval +/- intra-arterial t-PA and should refer to the risks listed below.

• The criteria that the patient has met making them eligible for endovascular thrombectomy should be documented.

• The natural history of stroke due to a large vessel occlusion (LVO) is associated with significant morbidity and mortality independent of procedural complications and may include haemorrhagic transformation, infarct extension and death. Nonetheless, the following risks are associated with ECR and should be documented:

  • Risk of intracranial bleeding that causes neurological worsening

  • Risk of vascular injury

  • Risk of access site major bleeding requiring treatment

  • Risk of access site injury or vasospasm resulting in occlusion of the femoral artery

  • Risk of failed procedure

  • Risk of new stroke

  • Risk associated with general anaesthetic and sedation

  • Risk of anaphylaxis or allergic reaction

  • Risk of serious morbidity or mortality as a direct result of this procedure is uncommon (estimated < 5% risk). *Probably lower in children but limited safety and efficacy data for endovascular thrombectomy in paediatric patients available.

PSI centre post-procedure care

• All patients will be transferred to PICU or 26 IOA following the procedure

• Patients who are not clinically stable would usually remain intubated and ventilated and be transferred to PICU.

• Patients who are clinically stable and who can follow age appropriate commands (taking into account deficits such as dysphasia) can be extubated following the procedure and transferred to Ward 26 IOA or PICU HDU assessed on a case by cases basis.

• Observation as per any post operative neurosurgical patient

• Routine post ECR orders include:

  • general and neurological observations

  • groin site checks and procedure access limb pulse checks

    • 15 minutely for 2 hours

    • Half hourly for 4 hours

    • Four hourly until reviewed

  • Report and document any clinical deterioration as per parameters determined by PICU and Paediatric Neurology

• If the patient has received IV Alteplase (tPA) then the relevant pathway for post-care following IV Alteplase (tPA) should also be followed

• Non-contrast CT should be performed to exclude haemorrhage at < 24 hours post procedure. MRI including DWI and TOF MRA (plus CE-MRA neck vessels in cases with dissection) is useful within the 48 hours following the procedure to assess efficacy and to prognosticate.

• Anti-platelets will be decided at the time of the procedure on a case-by-case basis through discussion between the interventional neuroradiologist and paediatric neurologist. These are usually withheld until after the post procedural CT and is also dependent on IV alteplase use.