Expansion
End organ damage, not the number, defines the emergency
Expansion
Emergency versus urgency
- Hypertensive emergency - severe hypertension with acute end organ damage. Needs intravenous treatment in a monitored setting
- Hypertensive urgency - severe hypertension without end organ damage. Needs oral treatment over days
“The number does not define it; the organ damage does.”
End organ damage to look for
- Eyes: retinal haemorrhages, exudates or papilloedema (grade III or IV retinopathy), which defines malignant hypertension
- Brain: encephalopathy, seizures, stroke, intracerebral haemorrhage
- Heart: acute coronary syndrome, acute pulmonary oedema, aortic dissection
- Kidney: acute kidney injury, haematuria, proteinuria
- Blood: microangiopathic haemolysis
- Obstetric: pre-eclampsia and eclampsia
The rate of reduction is the critical point: lower by no more than 25 per cent in the first hour, then to about 160/100 over 2 to 6 hours. Cerebral autoregulation has shifted rightwards in chronic hypertension, so a rapid fall causes cerebral, renal and coronary hypoperfusion.
The exceptions requiring rapid lowering are aortic dissection (target systolic under 120 within 20 minutes, with a beta blocker first) and pre-eclampsia.