Hypertensive crisis, hypertensive emergency

I10

DESCRIPTION

This is a life-threatening situation that requires immediate lowering of BP usually with parenteral therapy. Grade 3-4 hypertensive retinopathy is usually present, together with impaired renal function and proteinuria.

The true emergency situation should preferably be treated by a specialist.

Life-threatening complications include:

  • Hypertensive encephalopathy, i.e. severe headache, visual disturbances, confusion, seizures and coma that may result in cerebral haemorrhage.
  • Unstable angina or myocardial infarction.
  • Acute left ventricular failure with severe pulmonary oedema (extreme breathlessness at rest).
  • Eclampsia and severe pre-eclampsia.
  • Acute kidney failure with encephalopathy.
  • Acute aortic dissection.

MEDICINE TREATMENT

Admit the patient to a high-care setting for intravenous therapy and close monitoring. Do not lower the BP by > 25% within 30 minutes to 2 hours.
In the next 2–6 hours, aim to decrease the BP to 160/100 mmHg.
This may be achieved by the use of intravenous or oral medicines.

Intravenous therapy

  • Labetalol, IV, 2 mg/minute to a total dose of 1–2 mg/kg, while trying to achieve control with other agents.
    • Caution in acute pulmonary oedema.

OR

If myocardial ischaemia and CCF :

  • Glyceryl trinitrate, IV, 5–10 mcg/minute.

Refer to dosing table in section ST elevation myocardial infarction (STEMI).

AND

  • Furosemide, IV, 40–80 mg.
    • Duration of action: 6 hours.
    • Potentiates all of the above medicines.

Oral therapy

  • ACE-inhibitor, e.g.:
    • Enalapril, oral, 2.5 mg as a test dose.
      • Increase according to response, to a maximum of 20 mg daily.
      • Monitor renal function.

If ACE-inhibitor intolerant, i.e. intractable cough:

  • Angiotensin receptor blocker (ARB), e.g.:
    • Losartan, oral, 50–100 mg daily. Specialist initiated.