Cardiovascular · Topic 36 of 48

Hypertensive Urgency & Emergency

Cardiovascular · hypertensive crisis

Hypertensive Urgency & Emergency

Acute target-organ damage, not the number, makes the emergency: titratable IV drug in the ICU, lowering BP no more than 25% in the first hour.

Key numbers

Severe BP plus acute target-organ damage≥ 180/120 + organ damage

Lower BP ≤ 25% first hour≤ 25% in 1st hour

Dissection: SBP < 120, HR 60–80SBP < 120 mmHg

Ischemic stroke: permissive unless lysis planned< 185/110 before lysis

Intracerebral hemorrhage: SBP 130–140SBP 130–< 140

01 · What it isSevere BP plus acute target-organ damage

Hypertensive emergency = severe hypertension (usually ≥ 180/120 mmHg) with acute target-organ damage: encephalopathy, stroke, ACS, acute heart failure with pulmonary edema, aortic dissection, acute kidney injury, preeclampsia/eclampsia or severe retinopathy.

02 · DoLower BP ≤ 25% first hour

Reduce BP by no more than 25% in the first hour, then to about 160/100–110 over the next 2–6 hours, then to normal over 24–48 hours, using a titratable IV drug in the ICU.

03 · DoDissection: SBP < 120, HR 60–80

Aortic dissection is the exception: lower SBP immediately to < 120 mmHg (or the lowest level that perfuses) and heart rate to 60–80/min, with an IV beta-blocker (esmolol, labetalol) first, then a vasodilator if needed.

What it is

Core idea

Overly fast lowering causes ischemiaChronic hypertension shifts cerebral and renal autoregulation upward, so dropping BP to 'normal' quickly can cause stroke, myocardial ischemia or kidney injury — normal BP is not the urgent goal.

Presentation

What you'll see

Encephalopathy: global deficits plus papilledemaHypertensive encephalopathy causes global deficits (confusion, seizures, cortical blindness) with severe retinopathy or papilledema; focal deficits with normal mentation suggest stroke. Lower MAP about 20–25%.

Diagnosis & monitoring

Work-up

Look for organ damage: ECG, UA, creatinine, CTLook for target-organ damage: neurologic and fundoscopic exam, ECG, urinalysis (RBCs, casts, protein), electrolytes and creatinine, chest x-ray for chest pain or dyspnea, and head CT for any neurologic finding.

Nitroprusside: cyanide and thiocyanate toxicityNitroprusside is a last resort (higher mortality than alternatives): doses > 2 mcg/kg/min risk cyanide toxicity (agitation, anion-gap acidosis); prolonged use or renal failure causes thiocyanate accumulation — check levels after 3 days.

Do right now

In this order

First moves

Look for organ damage: ECG, UA, creatinine, CT

→

Titratable IV drug: nicardipine, clevidipine, labetalol, esmolol

→

Lower BP ≤ 25% first hour≤ 25% in 1st hour

Why each step

Titratable IV drug: nicardipine, clevidipine, labetalol, esmololUse a short-acting titratable IV agent — nicardipine, clevidipine, labetalol or esmolol are most used; clevidipine (onset 1–2 minutes, esterase-cleared) is a preferred choice. Oral agents are too slow and unpredictable.

Lower BP ≤ 25% first hourReduce BP by no more than 25% in the first hour, then to about 160/100–110 over the next 2–6 hours, then to normal over 24–48 hours, using a titratable IV drug in the ICU.

Management

Orders

No organ damage: oral drugs, no rapid lowering must knowSevere hypertension without acute target-organ damage (formerly 'hypertensive urgency') needs no immediate lowering: resume or intensify oral therapy, treat pain or anxiety, and follow closely; avoid as-needed IV antihypertensives in asymptomatic inpatients.

Ischemic stroke: permissive unless lysis planned must knowAcute ischemic stroke: lower BP to < 185/110 before thrombolysis and keep < 180/105 for 24 hours after; without reperfusion, treat only BP ≥ 220/120, lowering about 15% over 24 hours.

Intracerebral hemorrhage: SBP 130–140In spontaneous ICH with SBP 150–220 mmHg, lower SBP promptly to 130–< 140 mmHg and keep it there smoothly for at least 7 days; hold antihypertensives if SBP falls below 130.

Pulmonary edema or ACS: IV nitroglycerinFor acute pulmonary edema or myocardial ischemia, use IV nitroglycerin (with a loop diuretic in pulmonary edema); avoid labetalol and other beta-blockers in acute left ventricular failure.

Preeclampsia: labetalol, hydralazine or oral nifedipineSevere-range BP (≥ 160/110) in preeclampsia or eclampsia: give IV labetalol or hydralazine (or oral nifedipine), titrated to about 140–155/90–105, plus magnesium sulfate; delivery is definitive.

Catecholamine crisis: benzodiazepine, phentolamine, no lone beta-blockerPheochromocytoma crisis or cocaine/amphetamine toxicity: give IV phentolamine (and benzodiazepines for stimulant toxicity) and avoid unopposed beta-blockade.

Red flags & don'ts

Avoid harm

Never immediate-release nifedipine avoidDo not give short-acting oral or sublingual nifedipine: the precipitous fall in BP can cause fatal cerebral or myocardial ischemia.

Labetalol: avoid in asthma, heart block, acute HF avoidLabetalol (alpha and beta blocker) suits most emergencies, pregnancy and neurologic emergencies but is avoided in asthma, heart block and acute decompensated heart failure.

Hypertensive emergency or severe hypertension (urgency)?

Commonly confused

Blood pressure	Usually ≥ 180/120
Acute target-organ damage	Yes — brain, heart, aorta, kidney
Setting	ICU with continuous monitoring
Drugs	Short-acting titratable IV infusion
Speed	≤ 25% in the first hour

More detail

Reference

Show 5 reference facts

Above a MAP of about 160 mmHg (lower in previously normotensive patients), cerebral autoregulation fails and vessels dilate, producing cerebral edema.

After successful thrombectomy for large-vessel occlusion, targeting SBP < 140 mmHg in the first 72 hours worsens functional outcome (class 3: harm); after thrombolysis alone it gives no benefit.

Nicardipine is avoided in acute heart failure and used cautiously with myocardial ischemia; enalaprilat helps acute LV failure but is avoided in acute MI and pregnancy.

Fenoldopam, a peripheral dopamine-1 agonist, causes systemic and renal vasodilation with natriuresis; it can raise intraocular pressure and lower potassium.

Nitroprusside bags and tubing are wrapped against light because the drug degrades in ultraviolet light.

Pearl

Treat the organ, not the number — and lower slowly, except for the dissecting aorta.

Sources · Merck Manual Professional — Hypertensive Emergencies (updated Apr 2026, cites 2025 AHA/ACC) · Cooper University Health Care EM Daily — Treatment of Hypertensive Emergencies (2021) · Merck Manual Professional — Aortic Dissection · UIC Drug Information Group — Overview of the 2025 Hypertension Guidelines (Dec 2025) · Merck Manual Professional — Ischemic Stroke · The Management of Hypertensive Emergencies — Is There a "Magical" Prescription for All? J Clin Med 2022 · Management Strategies for Hypertensive Crisis: A Systematic Review. Cureus 2024 · Merck Manual Professional — Preeclampsia and Eclampsia · Practical Neurology — In-Hospital Blood Pressure Control After Acute Ischemic Stroke (Jan 2022) · emDocs — 2026 Guideline Update: Early Management of Acute Ischemic Stroke (AHA/ASA, Jan 2026) · Kulkarni S et al. Management of hypertensive crisis: British and Irish Hypertension Society position document. J Hum Hypertens 2023 · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).