Written by Thomas Davis.
The AHA released new 2018 guidelines, which are summarized for Emergency Physicians here. The new guidelines are great, but at 345 pages in length you may find it helpful to read the short version.
Why does this matter?
Stroke care is evolving rapidly. It can be difficult to keep up. Thrombectomy has changed the landscape. Make sure you are ready. This quick summary will help.
What’s new in stroke for emergency medicine physicians?
- Should EMS transport to a now ubiquitous “stroke center” that can give tPA or a comprehensive stroke center that can do thrombectomy? We still don’t know the answer but if the additional transport time is < 15 minutes, it seems reasonable to transfer to a comprehensive stroke center for suspected large vessel occlusions (LVO).
- Based on expert opinion only, door-to-needle time has been revised downward to 45 minutes. The goal is that at least 50% of patients should receive tPA within 45 minutes.
- Similarly, in order to give tPA faster, try to get imaging done within 20 minutes in at least 50% of patients. But don’t delay tPA for CTA or other imaging.
- If the patient has a suspected LVO, don’t wait for the creatinine to get a CTA if no known history of renal impairment.
- Get a CTA of the neck (not just head) for surgical planning. They need to know if the extracranial arteries are stenotic or tortuous.
- If stroke onset < 6 hrs and a potential candidate for thrombectomy, only get CTA (or MRA). However, if onset > 6 hrs, then CTP, DW-MRI, or MRI perfusion is recommended based on DAWN and DEFUSE-3 criteria.
- After getting a non-contrasted head CT, only withhold tPA for a bleed or for frank, extensive hypodensity. Don’t withhold tPA for other stroke findings such as a hyperdense MCA sign or loss of gray-white differentiation.
- If the patient has a known history of lots of cerebral microbleeds (i.e. > 10), talk to the neurologist. This increases the risk of symptomatic ICH to as high as 40%.
- For more rural centers without immediate stroke consultation to assist with decision to initiate tPA, teleneurology consults seem to be just as good. If no video consultation is available, just pick up the phone and talk to a neurologist.
- The only lab test you always need before giving tPA is glucose. If a patient is not on known anticoagulants, just give tPA. But if the lab tests come back abnormal (platelets < 100k, INR > 1.7, aPTT > 40 s), just stop the tPA.
- Giving tPA to patients with sickle cell disease seems beneficial.
- Use of antithrombotics within 24 hours of tPA administration may be safe. If there is a compelling concurrent indication (e.g. STEMI), the benefit likely outweighs the risk.
- Tenecteplase 0.4mg/kg IV bolus may be considered an alternative to tPA if needed. Data are very limited.
- Brief, moderate hyperventilation (PCO2 30-34) is reasonable as a bridge until definite therapy can treat cerebral edema.
What to do with blood pressure during stroke?
- Avoid hypotension. How low is bad? We don’t know.
- Avoid hypertension. How high is bad? We don’t know that either.
- If BP >220/120 mmHg or if there is a comorbid condition requiring BP treatment (e.g. aortic dissection), then decreasing BP by 15% is probably safe. Otherwise, there seems to be no benefit to treatment.
- For tPA and thrombectomy, keep BP < 180/105 mmHg.
2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2018 Jan 24. pii: STR.0000000000000158. doi: 10.1161/STR.0000000000000158. [Epub ahead of print]
Reviewed by Clay Smith.