Friday, February 26, 2010

What do hospitalists need to know about stroke care? is important now that the practicing hospitalist is facile in the treatment of patients with cerebrovascular disease-and it is likely to become progressively more important over time.

That's from the opening of a two part review on stroke in the Journal of Hospital Medicine.

Part 1. Part 2.

This two part series addresses issues in stroke care that bedevil hospitalists. I would suspect that, nation wide, as it is in many areas of medicine, best practice adherence in stroke care is low. This review should help.

First, the astute clinician is wary of stroke mimics. But when stroke is the working diagnosis an NIH stroke score should be done in the early moments in the ER (resource here).

In cases of intracerebral hemorrhage, although surgical indications are shrinking, patients may benefit from aggressive medical care and the review authors warn against an inappropriate rush to a DNR decision, citing literature that such a decision may be an independent risk factor for poor outcome (self-fulfilling prophecy).

In their discussion of tPA the authors mention the SITS-MOST study, a large phase IV study confirming that tPA performs as well as it did in the NINDS trial. The importance of informed consent for this risky therapy is emphasized (although written consent is not a firm requirement) and a discussion on administration of tPA when such consent is unobtainable is provided. Data in support of the new 4.5 hour time window are discussed although the authors come short of making a recommendation.

For patients who present too late for tPA but inside of 8 hours catheter based treatments (extraction or intra-arterial thrombolysis) are possible. Actually the most recent AHA/ASA guidelines only provide for a 6 hour window and read thusly:

Intra-arterial thrombolysis is an option for treatment of selected patients who have major stroke of <6>

If this type of treatment is “on the table” then CT angiography would be part of the stat imaging in the ER to identify or rule out a large vessel occlusion amenable to catheter based therapy. For this to go smoothly the interventional radiologist (either at your facility or the referral center) would need to be involved early in the ER planning to discuss timing, anticipated total dye loads, etc.

For patients presenting past 8 hours anti-platelet therapy is the only anti-thrombotic option early on. Aspirin should be given early. It is the only anti-platelet agent that has been studied for acute stroke. For patients already taking aspirin there is little to guide clinicians. That issue is discussed in detail in the text of the review.

Systemic anticoagulation is not recommended for any situation except cerebral venous sinus thrombosis, although in a few other situations systemic heparinization is considered. From part 1 of the review:

...a number of exceptions exist, based more on tradition and theory than on evidence. These exceptions, for which an IV heparin drip will at times still be considered, include acute ischemic stroke due to dissection of the carotid or vertebral arteries, cardioembolic stroke with fresh clot seen on echocardiogram (ECHO), and a clinically progressive syndrome suggestive of basilar artery occlusion...

Long term systemic anticoagulation with warfarin is indicated for patients with atrial fibrillation, but not with systemic heparinization in the acute phase. Nuances are discussed in the text of the review and in the guidelines.

Basilar artery occlusion syndrome and malignant middle cerebral artery occlusion syndrome are special situations which may warrant intra-arterial intervention and decompression craniotomy, respectively.

Discussions on general supportive care are included. A couple of points from the guidelines bear mention. The conservative threshold for acute hypertension treatment is well known, but absent such extreme blood pressure elevations what should be done with the patient's home blood pressure medication? The guidelines suggest starting them approximately 24 hours post stroke onset.

Glycemic control in hospitalized patients is controversial right now. In stroke, hyperglycemia is known to be associated with worse outcomes, but neither the target nor the threshold for intervention is precisely known. Accordingly, the guideline statement is vague:

The minimum threshold described in previous statements likely was too high, and lower serum glucose concentrations (possibly greater than 140 to 185 mg/dL) probably should trigger administration of insulin, similar to the procedure in other acute situations accompanied by hyperglycemia (Class IIa, Level of Evidence C).

Indications for carotid endarterectomy, arterial dissection and PFOV are discussed but a discussion of other indications for warfarin and for TEE (based on the TOAST classification) were conspicuously absent.

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