Controlled blood pressure reduction in accelerated phase hypertension
THE CONTEXT
Management requires a controlled fall in blood pressure because altered autoregulation makes rapid reduction hazardous.
Why rapid reduction is dangerous
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Lowering blood pressure too quickly can compromise tissue perfusion because autoregulation is altered.
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Consequences include cerebral damage, including occipital blindness, and precipitation of coronary or renal insufficiency.
Target and initial approach
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An ideal controlled reduction reaches about 150/90 mmHg over 24–48 hours, even when cardiac failure or hypertensive encephalopathy is present.
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Most patients can avoid parenteral treatment and achieve control with bed rest and oral drug therapy.
Parenteral treatment options
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Listed effective options are intravenous or intramuscular labetalol, intravenous GTN, intramuscular hydralazine and intravenous sodium nitroprusside.
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The passage lists labetalol at 2 mg/min to a maximum of 200 mg and intravenous GTN at 0.6–1.2 mg/hour.
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Intramuscular hydralazine is given in 5 or 10 mg aliquots repeated at half-hourly intervals; intravenous sodium nitroprusside is listed at 0.3–1.0 μg/kg body weight/minute.
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These treatments require careful supervision, preferably in a high-dependency unit.