Page 66 - Clinical Pearls in Cardiology

54 Clinical Pearls in Cardiology

fragmentation of red blood cells. The renal blood vessels
are particularly vulnerable to this hypertensive damage.
Renal damage due to these vascular changes is probably
the most important prognostic determinant in malignant
hypertension.
38. How will you manage high blood pressure in acute
ischemic stroke?
About 50% of patients with acute stroke will have
hypertension at the time of admission with systolic blood
pressure above 140 mm Hg. With serial measurements,
the blood pressure will usually decrease spontaneously
within the first 6 to 10 hours.
In observational studies, it has been shown that
systolic blood pressure in the range of 160–185 mm Hg
is associated with better outcomes than either lower or
higher blood pressure levels. The reason for this is that
a low blood pressure could lead to decreased perfusion
of the ischemic border zone of the infarcted area in
the brain, while a high blood pressure could promote
cerebral edema.
Guidelines recommend emergency parenteral
antihypertensive treatment in patients with acute
ischemic stroke only when systolic blood pressure is
more than 220 mm Hg and/or diastolic blood pressure
is more than 120 mm Hg (if thrombolysis is not indicated
or if there are no other compelling indications like co-
existing cardiac failure). Patients with blood pressures
lower than this level should be closely monitored for
the first 12 hours to observe for the spontaneous fall
in blood pressure* (Ref: The Washington Manual, 33rd
edition). In hemorrhagic stroke, the aim is to minimize
bleeding with a target blood pressure of around 140/90
mm Hg. Labetalol or nicardipine are the drugs of choice.