BP 240/130 with blurred vision, pulmonary oedema and creatinine climbing — the DAMAGE defines the emergency, not the number. Lower MAP ≤20–25% in the first 1–2 h.
ABCDE
Arterial line + cardiac monitoring; IV agent (nicardipine/labetalol/clevidipine) titrated to ≤20–25% MAP reduction in 1–2 h; treat the damaged organ in parallel.
Emergency vs urgency: emergency = severe hypertension + acute target-organ damage (encephalopathy, retinopathy, APE, ACS, AKI, microangiopathy); severe hypertension (>180/120, no acute damage, formerly "urgency") → oral agents, no ICU — do NOT give intermittent IV or oral agents solely to acutely lower BP in asymptomatic inpatients (2025 AHA/ACC)
Set up: ICU/HDU, arterial line, cardiac monitor; choose agent — nicardipine 5→15 mg/h, labetalol 20 mg IV boluses/infusion, or clevidipine 1→16 mg/h
Rate of reduction: MAP down ≤20–25% in the first 1–2 h, then toward ~160/100 by 6 h, normalise over 24–48 h — faster drops cause watershed stroke
Exceptions to the rule: aortic dissection → SBP <120 within 20 min; acute ischaemic stroke → permissive (treat only >220/120, or >185/110 before thrombolysis)
Special situations: pheochromocytoma → phentolamine (α before β); eclampsia → MgSO₄ + labetalol/hydralazine; sympathomimetic tox → benzodiazepines first
Organ-specific parallel care: APE → GTN infusion + NIV; ACS → GTN + ACS pathway; encephalopathy → treat seizure, MRI; AKI → stop nephrotoxins, watch potassium
Order set
- Arterial line + continuous monitoring
- Nicardipine 5 mg/h (titrate q5–15 min)
- GTN infusion if APE/ACS
- Urine output catheter
- ECG, troponin, U&E, urinalysis
- Fundoscopy + MRI brain if encephalopathy
Monitor
- q5–15 minBP during titration — never let MAP fall >25% in 2 h
- HourlyNeurology, urine output
- q4–6 hCreatinine, potassium
- 24–48 hTransition to oral agents before stepping down
Escalate / ICU
- Encephalopathy or seizures
- APE needing NIV
- AKI rapidly worsening
- Dissection/pheochromocytoma/eclampsia
Criteria
ICUAny acute target-organ damage
MAP drop≤20–25% first 1–2 h — never to 'normal' acutely
Stroke exceptionTreat only >220/120 (>185/110 pre-lytic)
Step-downStable on oral agents ×24 h, organ function plateaued
Never
- Drop BP to normal in the first hours — cerebral hypoperfusion and watershed infarction
- Use sublingual nifedipine — precipitous uncontrolled drops
- Give IV drips or intermittent agents for severe hypertension without organ damage (asymptomatic) — no acute lowering at all is recommended; oral therapy and observation suffice (2025 AHA/ACC)
Key
- The number never defines the emergency — encephalopathy, APE, ACS, AKI or retinopathy does
- Clevidipine is the smoothest titratable agent (short half-life, lipid emulsion)
- Always hunt the secondary cause later: renal artery, pheochromocytoma, primary aldosteronism
Clinical detail — differentials, red flags, pitfalls, disposition
Red flags
- Headache + confusion/seizures
- Chest pain or pulmonary oedema
- Oliguria with rising creatinine
- Retinal haemorrhages/papilloedema
Differentials
- Pain/anxiety-driven surge
- Recreational sympathomimetics (cocaine, amphetamine)
- Pheochromocytoma
- Medication non-adherence rebound (clonidine)
Common mistakes
- Over-correction → new neurological deficit
- Treating urgency with ICU drips
- Forgetting eclampsia in pregnancy
- No secondary workup before discharge
- ICH nuance: target SBP 130–<140 for presenting SBP 150–220 (2025 AHA/ACC)
Disposition & follow-up
ICU until on stable oral regimen; investigate secondary causes (renal ultrasound, aldosterone:renin, metanephrines); BP clinic within 1 week.
💊 Treatment detail — doses & preparation
NicardipineIV dihydropyridine
Dose5 mg/h IV, ↑2.5 mg/h q5–15 min to max 15 mg/h
Preparation25 mg in 250 mL D5W/NS (0.1 mg/mL) via pump; central line preferred (vesicant)
MonitorMAP, reflex tachycardia; change site if peripheral >12 h
Labetalol IVIV α+β-blocker
Dose20 mg IV over 2 min, repeat 20–80 mg q10 min (max 300 mg) or 0.5–2 mg/min infusion
Preparation200 mg in 160 mL (1.25 mg/mL) for infusion; boluses undiluted (5 mg/mL vial)
MonitorAvoid in asthma/decompensated HF; postural hypotension
ClevidipineIV dihydropyridine
Dose1–2 mg/h, double q2–5 min to max 16–21 mg/h
PreparationReady emulsion 0.5 mg/mL (50/100 mL vial) via pump — no dilution
MonitorLipid load, egg/soy allergy; ultra-short half-life = fast offset
Sodium nitroprussideIV vasodilator
Dose0.3–10 mcg/kg/min IV infusion
Preparation50 mg in 250 mL D5W (200 mcg/mL); wrap bag in foil — light sensitive; D5W only
MonitorCyanide toxicity if >72 h or renal failure; invasive MAP mandatory
Magnesium sulfate IVelectrolyte/antiarrhythmic
DoseTorsades: 2 g over 10–15 min. Asthma: 2 g over 20 min. Eclampsia: 4 g load then 1 g/h
Preparation2 g in 100 mL NS via pump; eclampsia 4 g in 100–200 mL
MonitorReflexes/RR if high doses (toxicity), Mg²⁺ level, renal function
📖 2025 AHA/ACC/Multisociety High BP guideline + textbook Ch.23Reviewed July 2026