Hypertensive emergency
Background
- High blood pressure without symptoms is NOT hypertensive emergency (see asymptomatic hypertension)
- Definition: acute target-organ damage due to severely elevated blood pressure
- Blood pressure is generally ≥180/110-120, but presence of end-organ damage defines disease (not absolute blood pressure number)
- 1%-6% of all ED patients will present with severe hypertension, but less than half of those will have target organ damage[1]
- From 2006-2013, hypertensive emergencies occurred in approximately 2 per 1000 adult ED visits[2]
Updated Terminology (AHA 2024)
The 2024 AHA Scientific Statement recommends retiring the terms "hypertensive urgency" and "hypertensive crisis"[2]
- Hypertensive emergency: SBP ≥180 or DBP ≥110-120 mmHg with new or worsening target-organ damage
- Asymptomatic markedly elevated BP: SBP ≥180 or DBP ≥110-120 mmHg without target-organ damage (replaces "hypertensive urgency")
- Asymptomatic elevated BP: SBP >130 or DBP >80 mmHg without target-organ damage
Etiology
- Idiopathic (medication nonadherence most common)
- Sympathomimetic drug use
- Preeclampsia
- Acute glomerulonephritis
- Pheochromocytoma
- Renal artery stenosis
- MAOI interactions
Prehospital
- Prehospital BP measurements should be considered reliable[3]
- Acute lowering of BP is not typically recommended in the prehospital setting
- Focus on ABCs (assess need for intubation or respiratory support)
- Provide care of treatable etiologies
- CHF
- Respiratory failure from pulmonary edema
- Acute pain
Clinical Features
End-Organ Dysfunction (BARKH Mnemonic)[2][4]
Use the BARKH mnemonic to systematically evaluate for target-organ damage:
- Brain
- Hypertensive encephalopathy (visual disturbances, seizure, delirium)
- Intracranial hemorrhage
- Acute ischemic stroke
- Arteries
- Retina
- High-grade hypertensive retinopathy (hemorrhages, exudates, papilledema)
- Kidney
- Acute kidney injury (often with microscopic hematuria)
- Microangiopathic hemolytic anemia (MAHA) / thrombotic microangiopathy[5]
- Heart
- Type-II myocardial infarction / unstable angina
- Acute LV failure with pulmonary edema
Differential Diagnosis
Hypertension
- Hypertensive emergency
- Stroke
- Sympathetic crashing acute pulmonary edema
- Ischemic stroke
- Intracranial hemorrhage
- Preeclampsia/Eclampsia
- Autonomic dysreflexia
- Scleroderma renal crisis
- Acute glomerulonephritis
- Type- I myocardial infarction
- Volume overload
- Urinary obstruction
- Drug use or overdose (e.g stimulants, especially alcohol, cocaine, or Synthroid)
- Renal Artery Stenosis
- Nephritic and nephrotic syndrome
- Polycystic kidney disease
- Tyramine reaction
- Cushing's syndrome
- Obstructive sleep apnea
- Pheochromocytoma
- Hyperaldosteronism
- Hyperthyroidism
- Anxiety
- Pain
- Oral contraceptive use
Evaluation
BP Measurement
- Ensure proper cuff size and technique before initiating treatment
- Confirm with repeat measurement in both arms; patient should be seated, back supported, feet on floor
- For patients receiving IV antihypertensives, arterial line monitoring is preferred for accuracy[2]
Workup
Consider any of the following based on the patient's clinical presentation[6][2]
- CBC with peripheral smear — assess for microangiopathic hemolytic anemia (schistocytes)
- Chem 8 — assess renal failure and possible secondary causes
- LDH, haptoglobin — if MAHA suspected
- Cardiac enzymes
- Urinalysis — assess renal failure, glomerulonephritis, preeclampsia
- ECG — LVH, ischemia
- Ultrasound — evaluate for aortic dissection, bladder outlet obstruction, or depressed myocardial function
- Fundoscopic Exam — evaluate for hypertensive retinopathy or papilledema
- CXR — evaluate for pulmonary edema or widened mediastinum (dissection)
- CT head — in hypertensive encephalopathy, may not show acute hemorrhage or other acute pathology
- Hypertensive encephalopathy is thought to be secondary to alteration in cerebral auto-regulation leading to posterior reversible encephalopathy syndrome. Most patients will show changes on MRI, although this is not necessarily indicated in the emergency department.
Diagnosis
- Must have evidence of end-organ dysfunction
- High blood pressure without symptoms is NOT hypertensive emergency (see asymptomatic hypertension)
- Symptoms such as headache, epistaxis and dizziness are not evidence of acute end-organ damage and they are not indication for acute BP reduction
Management
High blood pressure without end organ damage is NOT hypertensive emergency (see asymptomatic hypertension)
- Goal: Lower MAP by 20-25% in the first hour[7][8]
- Then lower gradually to 160/100 mmHg over the next 2-6 hours
- Then cautiously to normal over the next 24-48 hours
- Exception is aortic dissection which requires rapid reduction of systolic BP to 100-120 mmHg
- Be careful of lowering BP in patients with CVA
- Do NOT use IV antihypertensives for asymptomatic elevated BP, even if markedly elevated[2]
By Drug
First-Line Agents
| Drug | Dose | Mechanism | Pros | Cons | Notes |
| Nicardipine |
Start 5 mg/hr IV Increase by 2.5 mg/hr q5-15min Max 15 mg/hr |
Dihydropyridine CCB; decreases PVR |
1. Effective for most hypertensive emergencies 2. Good for intracranial pathology 3. Does not increase ICP 4. Achieves target BP in >90% within 30 min (CLUE trial)[9] |
1. Onset 5-15 min (slower than clevidipine) 2. Duration ~30-60 min; can accumulate 3. Reflex tachycardia possible |
1. Avoid in decompensated CHF, severe aortic stenosis 2. Often considered first-line for most hypertensive emergencies 3. In CLUE subgroup with EOD, 3.65× odds of reaching target vs labetalol[10] |
| Clevidipine |
Start 1-2 mg/hr IV Double q2 min until approaching target Then titrate by smaller increments q5-10 min Max 32 mg/hr |
Dihydropyridine CCB; arterial vasodilator |
1. Ultra-short half-life (~1 min); truly titratable 2. Organ-independent metabolism (ester hydrolysis in blood; safe in hepatic/renal failure) 3. Rapid onset (~2-3 min) 4. Lower risk of overshoot hypotension vs nicardipine |
1. Lipid emulsion vehicle (monitor triglycerides if >24hr) 2. Higher cost than nicardipine 3. Risk of rebound HTN after discontinuation |
1. Avoid in soy/egg allergy, severe aortic stenosis 2. Effective in stroke, perioperative HTN[11] 3. Similar initial BP control to nicardipine; nicardipine may have more sustained control[12] |
| Labetalol |
20 mg IV bolus initially Then 20-80 mg IV bolus q10 min OR 0.5-2 mg/min IV infusion Max cumulative bolus dose 300 mg |
Beta > α-blocker |
1. No significant change in HR or cerebral blood flow 2. Rapid onset (5-10 min) 3. Safe in pregnancy |
1. Avoid in COPD, decompensated CHF, 2nd/3rd degree heart block, severe bradycardia 2. Less effective at reaching target BP than nicardipine in CLUE trial (82.5% vs 91.7%)[9] |
1. Consider in ACS (when beta-blockade appropriate) 2. Consider in ischemic CVA 3. First-line in aortic dissection (provides rate and BP control) |
Second-Line / Specific-Use Agents
| Drug | Dose | Mechanism | Pros | Cons | Notes |
| Esmolol |
Load 250-500 mcg/kg over 1 min Infuse 50 mcg/kg/min If ineffective, repeat load and increase infusion by 50 mcg/kg/min up to 300 mcg/kg/min |
Beta-1 selective |
1. Very rapid on/offset (half-life 9 min) 2. Easily titratable |
1. Avoid in COPD, decompensated CHF, severe bradycardia 2. Does not significantly lower BP alone in severe HTN |
1. First-line for rate control in aortic dissection 2. Consider in ACS 3. Often used WITH a vasodilator (nicardipine/clevidipine) |
| Nitroglycerin | Start 5 mcg/min IV; titrate up to 200 mcg/min | Venodilator > arteriodilator |
1. Rapid onset/offset 2. Increases coronary blood flow 3. Reduces preload (ideal for pulmonary edema) |
1. Reflex tachycardia 2. Headache common 3. Tachyphylaxis with prolonged use |
Drug of choice in patients with cardiac ischemia, LV dysfunction, or pulmonary edema |
| Nitroprusside |
0.3-0.5 mcg/kg/min IV initial Max 2 mcg/kg/min (some refs up to 10) |
Arterial > venodilator |
1. Very effective 2. Immediate onset/offset |
1. Cyanide toxicity (especially with renal/hepatic failure or prolonged use) 2. Coronary steal 3. Increased ICP 4. Requires light-protected tubing |
Generally considered second- or third-line; safer alternatives preferred (nicardipine, clevidipine) Avoid in liver/renal failure, increased ICP, pregnancy |
| Phentolamine |
5-15 mg IV bolus q5-15 min OR 0.2-0.5 mg/min IV infusion |
α-blocker | Rapid onset | Reflex tachycardia |
Used for catecholamine-induced hypertension (pheochromocytoma, sympathomimetic toxicity) |
| Fenoldopam |
0.1-0.3 mcg/kg/min IV Titrate q15 min Max 1.6 mcg/kg/min |
Dopamine-1 agonist |
1. Increases renal blood flow and natriuresis 2. No toxic metabolites |
1. Reflex tachycardia 2. Avoid in glaucoma (increases IOP) |
Consider in hypertensive emergency with AKI/renal failure[13] |
| Enalaprilat | Bolus 1.25 mg IV over 5 min q6hr, titrate at 30 min intervals to max of 5 mg q6hr | ACE inhibitor; decreases HR, SV, systemic arterial pressure | Does not impair cerebral blood flow | Variable and unpredictable response |
1. Consider in high-renin states, CHF 2. Avoid in pregnancy 3. Limited role in ED |
| Hydralazine |
10-20 mg slow IV/IM q4-6 hr PRN Max 40 mg/dose |
Direct arterial vasodilator; onset 10-30 min, duration 2-4 hrs | Extensive safety data in pregnancy |
1. Unpredictable dose-response 2. Prolonged duration; not titratable 3. Reflex tachycardia 4. Can increase ICP |
Not recommended as first-line outside of pregnancy due to unpredictable response and inability to titrate[2] Primarily used in eclampsia/preeclampsia |
Note: Oral clonidine loading ("clonidine slam") is an outdated practice and is not recommended for hypertensive emergency in the ED. IV titratable agents are preferred.[2]
By Disease
Aortic Dissection
- Target SBP 100-120 and HR <60 within 20 min
- Beta-blockade BEFORE vasodilation to prevent reflex tachycardia
- Esmolol (preferred for titratability) OR labetalol alone
- Add nicardipine or clevidipine if BP remains elevated after adequate beta-blockade
- Adequate analgesia will decrease sympathetic drive
- Avoid volume depletion
- Avoid nitroprusside without prior beta-blockade
Pulmonary Edema
- Reduce BP by 20-30%
- Nitroglycerin is drug of choice (reduces preload)
- Clevidipine or nicardipine are alternatives[14]
- Promote diuresis AFTER vasodilation
- Avoid beta-blockers in acute decompensated heart failure
ACS
- No more than 20-30% reduction for SBP >160
- Nitroglycerin preferred (increases coronary flow)
- Consider beta-blocker (esmolol or labetalol) if no contraindication
- Avoid nicardipine/clevidipine as sole agents (lack antianginal properties)
Cocaine/Amphetamine Toxicity
- Benzodiazepines first (addresses underlying sympathetic surge)
- If refractory: nicardipine or clevidipine (pure vasodilators)
- Phentolamine for refractory cases
- Avoid pure beta-blockers (risk of unopposed alpha-stimulation)
- Labetalol (mixed alpha/beta) remains debated; some guidelines permit, others advise against[15]
Renal Failure
- Reduce BP by no more than 20%
- Avoid nitroprusside (cyanide metabolite accumulates in renal failure)
- Clevidipine (organ-independent metabolism), nicardipine, or fenoldopam (increases renal blood flow)
- Labetalol is an alternative
Eclampsia/Pre-eclampsia
- Goal BP <160/110
- Labetalol, nicardipine, or hydralazine
- Magnesium sulfate for seizure prophylaxis/treatment
- Avoid ACE inhibitors/ARBs, nitroprusside (teratogenic/fetal cyanide risk)
- Definitive treatment is delivery
Intracerebral Hemorrhage
- Target SBP <140 mmHg, initiated within 1 hour (INTERACT3 care bundle)[16]
- INTERACT3 demonstrated improved functional outcomes (OR 0.86, 95% CI 0.76-0.97) and reduced mortality with bundled care approach[16]
- Nicardipine, clevidipine, or labetalol
- Avoid nitroprusside (increases ICP)
- Care bundle also includes concurrent management of hyperglycemia, pyrexia, and anticoagulation reversal
- See current ICH guidelines for full recommendations
Ischemic Stroke
- SAH: See Subarachnoid Hemorrhage (SAH)
- If thrombolytic treatment is planned: goal SBP <185 and DBP <110 before administration[17]
- If no thrombolytics: consider BP reduction only if SBP >220 or DBP >120
- Nicardipine, clevidipine, or labetalol are all effective and safe
- Clevidipine may facilitate faster door-to-thrombolytic times due to rapid onset[18]
Pheochromocytoma
- Alpha-blockade first: Phentolamine
- Then add beta-blocker only after adequate alpha-blockade
- Nicardipine or clevidipine are alternatives
Disposition
- Hypertensive emergency: Admit to ICU or monitored setting for IV antihypertensive titration and close hemodynamic monitoring[7]
- Asymptomatic markedly elevated BP (formerly "urgency"):
- Do NOT treat with IV antihypertensives in the ED[2]
- Restart home medications
- Assess for and address contributing factors (pain, anxiety, medication nonadherence, urinary retention)
- Arrange close outpatient follow-up (24-72 hours)
- Evidence suggests potential harm from acute IV treatment of asymptomatic elevated BP[2]
See Also
Calculators
Mean Arterial Pressure (MAP)
| Parameter | Value |
|---|---|
| Systolic BP (mmHg) | |
| Diastolic BP (mmHg) | |
| MAP | mmHg |
| 70–105 | Normal — Adequate perfusion pressure. |
|---|---|
| <65 | Low — Risk of end-organ hypoperfusion. Target MAP ≥65 in septic shock (SSC 2021). |
| >105 | Elevated — Consider antihypertensive therapy based on clinical context. |
|
External Links
- emDocs - Hypertensive Emergency: Pearls and Pitfalls for the ED Physician
- EMCrit IBCC - Hypertensive Emergency
- emDocs - 2024 AHA Scientific Statement Review
References
- ↑ Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension. 2003;42(6):1206-1252. doi:10.1161/01.HYP.0000107251.49515.c2
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Bress AP, Anderson TS, Flack JM, et al. The management of elevated blood pressure in the acute care setting: a scientific statement from the American Heart Association. Hypertension. 2024;81(8):e94-e106. doi:10.1161/HYP.0000000000000238
- ↑ Cienki JJ, DeLuca LA. Agreement between emergency medical services and expert blood pressure measurements. J. Emerg Med. 2012;43(1):64-68.
- ↑ Levy PD. Hypertensive Emergencies — On the Cutting Edge. EMCREG - International. 2011. 19-26.
- ↑ Cremer A, Amraoui F, Lip GY, et al. From malignant hypertension to hypertension-MOD: a modern definition for an old but still dangerous emergency. J Hum Hypertens. 2016;30(8):463-466. doi:10.1038/jhh.2015.82
- ↑ 2013 Practice guidelines for the management of arterial hypertension of the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC): ESH/ESC Task Force for the Management of Arterial Hypertension. J Hypertens. 2013;31(10):1925-1938.
- ↑ 7.0 7.1 2025 AHA/ACC/AANP/AAPA/ABC/ACCP/ACPM/AGS/AMA/ASPC/NMA/PCNA/SGIM Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults. Hypertension. 2025;82(10):e212-e316. doi:10.1161/HYP.0000000000000249
- ↑ Elliott WJ. Clinical features in the management of selected hypertensive emergencies. Prog Cardiovasc Dis. 2006;48(5):316-325. doi:10.1016/j.pcad.2006.02.004
- ↑ 9.0 9.1 Peacock WF, Varon J, Baumann BM, et al. CLUE: a randomized comparative effectiveness trial of IV nicardipine versus labetalol use in the emergency department. Crit Care. 2011;15(3):R157. doi:10.1186/cc10289
- ↑ Levy PD, Mahn JJ, Miller J, et al. Intravenous nicardipine and labetalol use in hypertensive patients with signs or symptoms suggestive of end-organ damage in the emergency department: a subgroup analysis of the CLUE trial. BMJ Open. 2013;3(3):e002338. doi:10.1136/bmjopen-2012-002338
- ↑ Brehaut SS, Roche AM. Emergency department and critical care use of clevidipine for treatment of hypertension in patients with acute stroke. Crit Pathw Cardiol. 2025;24(1):e0375. doi:10.1097/HPC.0000000000000375
- ↑ Storey C, Pouliot J. Evaluation of the efficacy and safety of nicardipine versus clevidipine for blood pressure control in hypertensive crisis. J Emerg Med. 2024;67(3):e267-e275.
- ↑ Fink JT, Singh I. Treatment of hypertensive emergencies. Proc (Bayl Univ Med Cent). 2017;30(2):214-216.
- ↑ Fink JT, Singh I. Treatment of hypertensive emergencies. Proc (Bayl Univ Med Cent). 2017;30(2):214-216.
- ↑ Richards JR, Garber D, Laurin EG, et al. Treatment of cocaine cardiovascular toxicity: a systematic review. Clin Toxicol (Phila). 2016;54(5):345-364. doi:10.3109/15563650.2016.1142090
- ↑ 16.0 16.1 Ma L, Hu X, Song L, et al. The third Intensive Care Bundle with Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT3): an international, stepped wedge cluster randomised controlled trial. Lancet. 2023;402(10395):27-40. doi:10.1016/S0140-6736(23)00806-1
- ↑ Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the early management of patients with acute ischemic stroke: 2019 update. Stroke. 2019;50(12):e344-e418. doi:10.1161/STR.0000000000000211
- ↑ Brehaut SS, Roche AM. Emergency department and critical care use of clevidipine for treatment of hypertension in patients with acute stroke. Crit Pathw Cardiol. 2025;24(1):e0375.
