Related Subjects:
|Assessing Chest Pain
|Hypertension
|Hypertension in Pregnancy
|Malignant Hypertension
|Preeclampsia, Eclampsia and HELLP
|Acute Heart Failure
|Chronic Heart Failure
|Essential Hypertension
⚠️ Key Point: Patients with malignant hypertension may be volume-depleted due to pressure-induced natriuresis. Careful IV saline replacement may be required alongside antihypertensive therapy.
📖 About
- Malignant Hypertension: Severe elevation in blood pressure with acute end-organ damage (retinal, renal, neurological).
- Historically more common in middle-aged men. 📉 Incidence has declined with better BP screening/management.
🧾 Diagnosis
- Threshold: SBP >220 mmHg and/or DBP ≥120 mmHg.
- End-Organ Damage:
- 👁️ Retinopathy: haemorrhages, exudates, papilloedema
- 🧪 Renal: AKI
- ❤️ Cardiac: ACS, LV failure
🩺 Clinical Features
- Headache, severe anxiety, agitation
- Acute pulmonary oedema 🌊
- Microangiopathic haemolytic anaemia (MAHA)
- Renal impairment, haematuria/proteinuria
- Neurological: stroke (ischaemic/haemorrhagic), confusion, delirium
👁️ Hypertensive Retinopathy Scale
| Grade | Features |
|---|
| I | Mild arteriolar narrowing/sclerosis |
| II | Marked narrowing, AV nipping |
| III | Narrowing + haemorrhages, cotton-wool spots |
| IV | All above + papilloedema |
🔬 Investigations
- Bloods: FBC, U&E, LFTs, urinalysis (proteinuria, haematuria).
- ECG: LV strain, ischaemia.
- Echo: LVH, systolic/diastolic dysfunction.
- Renal Imaging: US/MRA → renal size, asymmetry, artery stenosis.
- Secondary causes:
- ↑ Cortisol → Cushing’s
- Urinary catecholamines/metanephrines → pheochromocytoma
- Tox screen → cocaine/stimulants
🚨 Red Flags (Urgent Treatment Needed)
- 🔪 Aortic dissection
- 🌊 Acute LV failure / pulmonary oedema
- 🧪 Worsening renal failure
- 🧠 Hypertensive encephalopathy
- 🩸 Stroke (ischaemic or haemorrhagic)
- ⚡ Hyperadrenergic states (pheochromocytoma, cocaine)
- ❤️ ACS / Unstable angina / MI
- 🤰 Eclampsia
🎯 Treatment Goal: Reduce MAP by ≤20–25% in first few hours.
Targets: SBP <200 mmHg or <180/120 mmHg depending on scenario.
👉 Always seek expert input in emergencies.
💊 Management Principles
- Gradual reduction: In long-standing HTN without acute injury, lower slowly (target SBP 160–180 initially).
- Address contributors: Pain, agitation, urinary retention, alcohol withdrawal.
- Oral agents (non-urgent): Amlodipine, low-dose beta-blocker, ACE inhibitor.
- IV agents (urgent):
- IV labetalol, nitroprusside, nitroglycerin
- Loop diuretics if volume overload
- Chest pain → IV nitrates + beta-blockers
- Aortic dissection → IV beta-blockade (labetalol) then nitroprusside (target ~120/80)
- Pregnancy (preeclampsia/eclampsia): Labetalol ± nifedipine/methyldopa. Add MgSO4 for seizure prophylaxis.
- Stroke:
- Haemorrhage: lower SBP to 140–150 mmHg with IV labetalol/nicardipine.
- Ischaemic: treat only if >220/120, or >185/110 if thrombolysis planned.
📊 Specific Clinical Scenarios
| Emergency |
Timeline & Target BP |
First-Line |
Alternative |
| HTN crisis + retinopathy/AKI/MAHA | Hours; MAP ↓20–25% | Labetalol | Nitroprusside, Nicardipine |
| Hypertensive encephalopathy | Immediate; MAP ↓20–25% | Labetalol | Nicardipine |
| Aortic dissection | Immediate; SBP <110 | Labetalol ± Nitroprusside | Metoprolol + Nitroprusside |
| Pulmonary oedema | Immediate; MAP 60–100 | Nitroprusside + diuretic | Nitroglycerine |
| ACS | Immediate; MAP 60–100 | Nitroglycerine | Labetalol |
| Ischaemic stroke (>220/120) | 1h; MAP ↓15% | Labetalol | Nicardipine |
| Cerebral haemorrhage | 1h; SBP <180, MAP <130 | Labetalol | Nicardipine |
| Ischaemic stroke + thrombolysis | 1h; BP <185/110 | Labetalol | Nicardipine |
| Cocaine/XTC intoxication | Hours; SBP <140 | Benzodiazepines → Phentolamine | Nitroprusside |
| Pheochromocytoma crisis | Immediate | Phentolamine | Nitroprusside |
| Peri-op HTN (CABG) | Immediate | Nicardipine | Nitroglycerine |
| Post-craniotomy HTN | Immediate | Nicardipine | Labetalol |
| Severe preeclampsia/eclampsia | Immediate; BP <160/105 | Labetalol + MgSO4 | Nifedipine, Nicardipine |
