Do you want to do something with that blood pressure?

by Bob Stuntz

A 64 year old woman comes in with sudden onset left sided weakness about 7 hours minutes prior to arrival.  You perform an exam and find her to have left sided weakness and sensory defecit.  Blood pressure is 207/110.  CT of the head shows no hemorrhage.  You are going to be admitting the patient for ischemic CVA, when the nurse asks you the above question.  What do you say?  What if the patient was here 30 minutes after symptom onset with an NIH stroke scale score of 14 (i.e., they’re a tPA candidate)?  What about if that blood pressure was 230/140?  We will address each issue in a separate post.  For today:

Ischemic Stroke: There have been studies showing that people who have stroke and are severely hypertensive or hypotensive have worse outcomes, but these results are countered by studies showing that aggressive lowering of BP in the setting of acute ischemic stroke leads to hypo perfusion of the affected area and worsening of the stroke itself.  What to do?

The urge to treat makes sense.  Theoretically, higher blood pressure should put you at risk for worsening brain edema and hemorrhagic transformation of stroke.  And let’s face it, you want to do something.  It is important to remember the physiology of stroke, however.  Most of these people are probably walking around hypertensive (cynical but true), so their brains are used to higher perfusion pressures.  Now you have clotted off an artery, and that area needs even higher pressures to perfuse the brain.  If you tank their pressure too fast, you now are not perfusing their ischemic brain and causing worsening of their stroke.  That’s the opposite of what you want to do.  

I mentioned studies.  The problem is, the results of all of these studies are heterogenous. There is no definitive study showing one method or the other to be far superior.  The AHA, however, does have a document describing the expert panel consensus on this very matter, the most recent being from 2007 (1).  By their recommendations, BP should be managed as follows in ischemic stroke:

A. Most people with HTN on presentation will improve spontaneously with time.  Let them pee, treat their pain, turn the light off, move the psych patient next door.  Make them more comfortable, and it usually gets better.  I like to call this “benign neglect,”  and it is by far my favorite treatment for hypertension in general in the ED.  

B.  If they have an issue related to CVA that requires antihypertensive therapy, such as aortic dissection or hypertensive encephalopathy, by all means treat.  

C. Treatment of hypertension in ischemic stroke should be limited to those who have BP > 225 systolic or > 120 diastolic that is persistent, with a goal to reduce by 15-25% within the first DAY.  That’s right, 24 hours.  The AHA admits in the consensus statement that these numbers are somewhat arbitrary (the level of evidence here is pretty low).  

Again, remember the evidence here is not overwhelming.  Seeing as the goal is to decrease over 24 hours, you could even make the argument this is the job of the admitting team.  I won’t judge you.  However, remember that we do know people who come in severely hyper- or hypo-tensive do very poorly.  Go by the guidelines.  Their recommendations for meds (as long as contraindications do not exist):

- Labetolol 10-20 mg IV, repeated or doubled PRN q 10 minutes to a max of 300 mg OR

- Nicardipine gtt @ 5mg/hr, increased by 2.5 mg/hr q 5 min to a max dose of 15 mg/min OR

- Nitroprusside gtt 0.5 mcg/kg/hour

Since you have a narrow treatment window and you want to be careful in lowering BP, consider an arterial line with continuous pressure monitoring in these patients, especially when administering a drip.  

Incidentally, a study earlier this year showed that we tend to do far too much and over treat in this case (2).  It found that only about 1/3 patients with acute ischemic stroke that we treat with antihypertensives met the above referenced guidelines, and it was not infrequent that we were too aggressive in our BP management.  I know you want to do things.  You didn’t go into EM to sit around and not act.  But this is a case where you really need to keep yourself from firing that order off without making sure it is indicated.  

We will discuss the other two scenarios in the next few days.  

1.  Stroke.  2007; 38: 1655-1711.  Guidelines for the Early Management of Adults With Ischemic Stroke.  Adams HP et al.  

2. Stroke. 2012 Feb;43(2):557-9. Epub 2011 Oct 27.  Emergency department adherence to American Heart Association guidelines for blood pressure management in acute ischemic stroke.  Grise EM, et. al.