Malignant HTN/ Accelerated HTN

Introduction

Hypertensive emergencies are-

• Patients with severe hypertension (diastolic pressure >140 mmHg)
• Malignant hypertension (grades 3 or 4 retinopathy),
• Hypertensive encephalopathy or
• with severe hypertensive complications, such as cardiac failure, Renal failue

Management

• Immediate hospitalization
• bed rest and oral drug therapy

Caution:

It is unwise to reduce the blood pressure too rapidly, since this may compromise tissue perfusion (due to altered autoregulation) and can cause cerebral damage, including occipital blindness, and precipitate coronary or renal insufficiency

• So, blood pressure response to therapy must be carefully monitored, preferably in a high-dependency unit (HDU)
• In most cases, the aim is to reduce the diastolic blood pressure to 100–110 mmHg over 24–48 hours^P.

• Even in the presence of cardiac failure or hypertensive encephalopathy, a controlled reduction to a level of about 150/90 mmHg over a period of 24–48 hours^D is ideal.

• This is usually achieved with oral medication, e.g. amlodipine.^P

• The blood pressure can then be normalized over the next 2–3 days.

[ When rapid control of blood pressure is required (e.g.in an aortic dissection), the agent of choice is intravenous sodium nitroprusside. Alternatively, an infusion of labetalol can be used. The infusion dosage must be titrated against the blood pressure response.]

• Labetalol (2 mg/min to a maximum of 200 mg) iv or im
• Glyceryl trinitrate (0.6–1.2 mg/hr) iv
• (5 or 10 mg aliquots repeated at half hourly intervals) im
• Sodium Nitroprusside (0.3–1.0 µg/kg body weight/min) iv

Caution:

These must require careful supervision, preferably in a high dependency unit