The levels of evidence supporting the recommendations (I-IV) and grades of recommendations (A-D and clinical practice points [CPP]) are defined at the end of the "Major Recommendations" field.
The original guideline document also includes a consumer rating that identifies aspects of care considered to be critical from a patient perspective.
These guidelines use the ABCD2 tool (see "Definitions" at the end of the "Major Recommendations" field); patients with a rating >4 are designated HIGH risk and those <4 are LOW risk.
Assessment of Transient Ishaemic Attack (TIA)
All patients with suspected TIA should have a full assessment that includes assessment of stroke risk using the ABCD2 tool at the initial point of health care contact whether first seen in primary or secondary care. (Grade B; Level II [Johnston et al., 2007])
The following investigations should be undertaken routinely for all patients with suspected TIA: full blood count, electrolytes, renal function, cholesterol level, glucose level, and electrocardiogram. (CPP)
Patients classified as high risk (ABCD2 >4) should have an urgent computed tomography (CT) brain ('urgent' is considered as soon as possible, but certainly within 24 hours). Carotid duplex ultrasound should also be undertaken urgently in patients with carotid territory symptoms who would potentially be candidates for carotid re-vascularisation. Patients classified as low risk (ABCD2 <4) should have a CT brain and carotid ultrasound (where indicated) as soon as possible (i.e., within 48-72 hours). (Grade B; Level 1 [Johnston et al., 2007; Wardlaw et al., 2004; Wardlaw et al., 2006] & Level III-3 [Douglas et al., 2003])
Triage in Emergency Department
Diagnosis should be reviewed by a clinician experienced in the evaluation of stroke. (Grade C; Level III-3 [Kothari et al., 1995; Martin et al., 1997])
Emergency department (ED) staff should use a validated stroke screen tool to assist in rapid accurate assessment for all people with stroke. (Grade C; Level II [Nor et al., 2005])
Local protocols developed jointly by staff from pre-hospital emergency services, the hospital ED and the stroke unit should be used for all people with suspected stroke. Such protocols should include early notification by paramedic staff, high priority transportation and triage, rapid referrals from ED staff to stroke specialists and rapid access to imaging. (Grade D; Level III-3 & IV [Kwan, Hand, & Sandercock, 2004; Bray et al., 2005; Lindsberg et al., 2006])
Imaging
All patients with suspected stroke should have an urgent brain CT or magnetic resonance imaging (MRI) ('urgent' is considered as soon as possible, but certainly less than 24 hours). (Grade A; Level I [Wardlaw et al., 2004])
A repeat brain CT or MRI should be considered urgently when a patient's condition deteriorates. (CPP)
All patients with carotid territory symptoms who would potentially be candidates for carotid re-vascularisation should have an urgent carotid duplex ultrasound. (Grade B; Level I [Wardlaw et al., 2006])
Further brain, cardiac or carotid imaging should be undertaken in selected cases including:
- Patients where initial assessment has not confirmed likely source of ischaemic event
- Patients with a history of more than one TIA
- Patients likely to undergo carotid surgery
(Grade B; Level I [Wardlaw et al., 2004; Wardlaw et al., 2006] Level III-2 [Kapral et al., 1999])
Investigations
The following investigations should be obtained routinely in all patients – full blood picture, electrocardiogram, electrolytes, renal function, fasting lipids, erythrocyte sedimentation rate and/or C-reactive protein, and glucose. (CPP)
Selected patients may require the following additional investigations: angiography, chest x-ray, syphilis serology, vasculitis screen and prothrombotic screen. These tests should be performed as soon as possible after stroke onset, and in selected patients, some of these tests may need to be performed as an emergency procedure. (CPP)
Definitions:
Levels of Evidence
Level |
Intervention |
Diagnosis |
Prognosis |
Aetiology |
Screening |
I |
A systematic review of Level II studies |
A systematic review of Level II studies |
A systematic review of Level II studies |
A systematic review of Level II studies |
A systematic review of Level II studies |
II |
A randomised controlled trial |
A study of test accuracy with: an independent, blinded comparison with a valid reference standard, among consecutive patients with a defined clinical presentation |
A prospective cohort study |
A prospective cohort study |
A randomised controlled trial |
III-1 |
A pseudo-randomised controlled trial (i.e., alternate allocation or some other method) |
A study of test accuracy with: an independent, blinded comparison with a valid reference standard, among consecutive patients with a defined clinical presentation |
All or none |
All or none |
A pseudo-randomised controlled trial (i.e., alternate allocation or some other method) |
III-2 |
A comparative study with concurrent controls:
- Non-randomised experimental trial
- Cohort study
- Case-control study
- Interrupted time series without a parallel control group
|
A comparison with a reference standard that does not meet the criteria required for Level II and Level III-1 evidence |
Analysis of prognostic factors amongst untreated control patients in a randomised controlled trial |
A retrospective cohort study |
A comparative study with concurrent controls:
- Nonrandomised, experimental trial
- Cohort study
- Case-control study
|
III-3 |
A comparative study without concurrent controls:
- Historical control study
- Two or more single arm study
- Interrupted time series without a parallel control group
|
Diagnostic case-control study |
A retrospective cohort study |
A case-control study |
A comparative study without concurrent controls:
- Historical control study
- Two or more single arm study
|
IV |
Case series with either post-test or pre-test/post-test outcomes |
Study of diagnostic yield (no reference standard) |
Case series or cohort study of patients at different stages of disease |
A cross-sectional study |
Case series |
Grades of Recommendations
Grade |
Description |
A |
Body of evidence can be trusted to guide practice |
B |
Body of evidence can be trusted to guide practice in most situations |
C |
Body of evidence provides some support for recommendation(s) but care should be taken in its application |
D |
Body of evidence is weak and recommendation must be applied with caution |
Clinical Practice Points |
CPP |
Recommended best practice based on clinical experience and expert opinion |
ABCD2 Tool*
A Age: >60 years (1 point)
B Blood pressure: >140/90 mmHg (1 point)
C Clinical features: unilateral weakness (2 points), speech impairment without weakness (1 point)
D Duration: >60mins (2 points), 10-59 mins (1 point)
D Diabetes (1 point)
|
*(Johnston et al., 2007)