Hypertensive Emergency

Think of hypertensive emergency as a severe BP reading that is already hurting an organ. The reading is commonly SBP above 180 or DBP above 120 mm Hg, and the organ damage is new or getting worse. The 2024 AHA scientific statement on elevated blood pressure in the acute care setting explains how these readings are labelled and managed in hospital.

Autoregulation gives out at very high pressure. Then the brain, heart, kidney, retina and aorta take pressure and shear stress they cannot tolerate. The injury depends on three things: how high the pressure is, how fast it rose, and which organ is affected. The number alone does not define the emergency.

• Organs at risk: brain (encephalopathy, ischemic stroke, intracerebral hemorrhage), heart (acute coronary syndrome, acute heart failure with pulmonary edema), kidney (hypertensive kidney injury), retina, aorta (dissection), and pregnancy (see the Preeclampsia, Eclampsia and HELLP Syndrome page).
• Common causes: uncontrolled chronic hypertension with missed medicines, sympathomimetic toxicity (cocaine, methamphetamine), catecholamine excess (for example pheochromocytoma), medication withdrawal, and renal artery disease.
• Severe asymptomatic hypertension: high BP with no new organ injury. You recheck it, evaluate it and set up an outpatient plan. It does not get an acute IV infusion.

Typical presentation

You see a very high reading paired with a symptom that points to one organ: a new neurologic change, chest pain, breathlessness with crackles, or a tearing pain. Often the BP turns up while you assess that symptom. It is not the chief complaint.

Red Flags

• Confusion, focal weakness, speech change, severe headache or seizure with SBP >180 or DBP >120 mm Hg
• Chest pain, new ischemic ECG change, or new pulmonary edema with a falling SpO₂
• Tearing chest or back pain, or a large difference between arm pressures (possible aortic dissection)
• Visual change, or urine output falling while BP is high
• Pregnancy or postpartum up to 6 weeks: follow the preeclampsia pathway
• Stimulant use with chest pain or agitation

The full workup happens in the ED. In the field, your first decisions come from a repeat BP, a neuro check, glucose, SpO₂ and the 12-lead ECG.

• Ischemic stroke or intracerebral hemorrhage: a severe headache with high BP can be a bleed. The CT result tells you the BP target. See Hemorrhagic Stroke.
• Stimulant toxicity: Cocaine and methamphetamine push up BP and heart rate. They can also bring on chest pain and agitation. See Toxidromes.
• Seizure or hypoglycemia: A seizure with a high reading may have a metabolic cause, so check glucose first. If the seizure keeps going, follow Status Epilepticus.
• Pain or anxiety: Pain and anxiety both raise BP. If the BP falls once the pain or agitation is treated, do not write off the chest pain as non-cardiac.
• Preeclampsia or eclampsia: New hypertension in pregnancy, or up to 6 weeks postpartum, goes down the Preeclampsia pathway.

1. Assess: take a BP reading if a monitor is available and record the time. Do not give BP medicines beyond your scope.
2. Position by symptom: upright for breathlessness, recovery position for vomiting or seizure, and protect from falls.
3. Oxygen and airway: give oxygen for hypoxia per protocol and support breathing as needed.
4. Assist with the patient's own medicines only where state and agency protocol allow.
5. Monitor: recheck BP and mental status at least every 15 minutes during transport.
6. Notify early: report the symptom onset time, BP trend, medicines, drug use and whether the patient is pregnant or postpartum.

Doses vary by protocol; follow local protocols and medical direction. Get IV access and monitoring on first. A high number alone is not the trigger. Treat the BP only when it sits in the severe range and an organ is affected. Everything below is for advanced-level clinicians (Paramedic/RN/CCT), and only where your scope allows.

• IV access and monitoring: continuous ECG and SpO₂, and BP at least every 5–15 minutes per protocol.
• Labetalol (Paramedic/RN/CCT): 20 mg IV over 2 min, then 20–80 mg every 10 min while BP stays severe (max 300 mg cumulative), or an infusion starting at 2 mg/min and titrated (cumulative dose not above 300 mg). Avoid in asthma, severe bradycardia, heart block beyond first degree and overt heart failure. See Labetalol
• Hydralazine (Paramedic/RN/CCT): a less-preferred, non-titratable option only where protocol lists it: 10 mg IV slowly for non-pregnant adults (max initial dose 20 mg), recheck BP in 20 minutes. Nicardipine, clevidipine or labetalol are preferred. Reflex tachycardia can bring on angina. Don't use it as the only agent in suspected aortic dissection. See Hydralazine
• Nitroglycerin for ACS or pulmonary edema (Paramedic): 0.4 mg SL every 5 min, max 3 doses, when SBP is at least 90 mm Hg. Do not give to a patient with suspected right ventricular infarction, recent sildenafil or vardenafil (within 24 hours), recent tadalafil (within 48 hours), or riociguat. See Nitroglycerin
• Target: come down in steps, not all at once. Never push BP below the target for the organ at risk. Hit the target? Stop titrating and reassess.
• Sympathomimetic toxicity (cocaine, methamphetamine): Agitation and tachycardia get a benzodiazepine first. Treat the BP only if it stays severe, with nitroglycerin or nicardipine per protocol. Avoid beta-blockade alone. See Toxidromes
• Suspected pheochromocytoma or catecholamine crisis: Alpha blockade comes first, before any beta-blocker: phentolamine, or nicardipine per medical direction. Beta-blockade without alpha blockade can make BP worse. Follow medical direction.
• Suspected stroke: Follow the stroke pathway before lowering BP. Don't lower it in the field without the stroke team's target. See Acute Ischemic Stroke
• Pregnancy: take the Preeclampsia pathway. In eclampsia, magnesium goes first.

• General target: cut BP by no more than about 25% in the first hour. After that, if the patient is stable, bring it toward about 160/100 mm Hg over 2–6 hours, then cautiously toward normal over 24–48 hours. Dissection, stroke, intracerebral hemorrhage and pregnancy each get their own target, as below.
• Ischemic stroke without reperfusion (2019 AHA/ASA thresholds): treat only if BP is above 220/120 mm Hg. Then lower it about 15% over the first 24 hours. Before thrombolysis, keep BP below 185/110 mm Hg. After thrombolysis, keep it below 180/105 mm Hg for at least 24 hours. These are the 2019 values. The stroke team and local protocol set the final target. Thrombectomy limits follow the stroke pathway. See Acute Ischemic Stroke
• Nicardipine (ED/ICU): start 5 mg/hr IV and increase by 2.5 mg/hr every 5–15 minutes to a max of 15 mg/hr. After rapid titration, reduce to 3 mg/hr. Contraindicated in advanced aortic stenosis. See Nicardipine
• Clevidipine (ED/ICU): start 1–2 mg/hr IV, doubling every 90 seconds at first, then smaller steps every 5–10 minutes. Usual 4–6 mg/hr; maximum 16 mg/hr and no more than 1,000 mL per 24 hours. Contraindicated with soy or egg allergy, severe aortic stenosis, and defective lipid metabolism (pancreatitis, hyperlipidemia or lipoid nephrosis). See Clevidipine
• Sodium nitroprusside (ICU): Watch the boxed warning: it can cause precipitous hypotension, and the concentrate must be diluted before use. Start 0.3 mcg/kg/min IV, max 10 mcg/kg/min. Never run at the maximum rate for more than 10 minutes. Cyanide builds up with prolonged use. Thiocyanate builds up in renal impairment, and cyanide risk climbs in hepatic impairment. Protect the infusion from light and use an arterial line. Treat cyanide toxicity with hydroxocobalamin or sodium thiosulfate per toxicology. Not used for compensatory hypertension (for example aortic coarctation), AV shunt, congenital optic atrophy or tobacco amblyopia.
• Aortic dissection: beta-blocker first, then a vasodilator. Aim for a heart rate of about 60–80/min and SBP below 120 mm Hg, and reach it as fast as the patient tolerates. Esmolol 500 mcg/kg IV over 1 min, then 50 mcg/kg/min, titrated in steps toward the heart rate and SBP goal (label maximum 300 mcg/kg/min). Add nicardipine, clevidipine or nitroprusside only after beta-blockade, and only if SBP stays above target. When a beta-blocker is contraindicated, bring in specialist input on a non-dihydropyridine calcium channel blocker. See Esmolol
• Intracerebral hemorrhage with SBP 150–220 mm Hg: bring SBP toward 140 mm Hg and keep it within 130–150 mm Hg (2022 AHA/ASA guideline). Avoid SBP below 130 mm Hg, which may be harmful. Agree the target with the stroke team. See Hemorrhagic Stroke
• Pulmonary edema with hypertension: IV nitroglycerin infusion with noninvasive ventilation per protocol. See Nitroglycerin

• Destination: a center that can run titratable infusions and manage the injured organ. That means a stroke center for stroke or hemorrhage, a PCI center for ACS, and a cardiac surgery center for suspected aortic dissection, per local protocol.
• In transit: keep infusions on a pump at the programmed rate. Do BP and neuro checks every 5–15 minutes per protocol, with continuous ECG and SpO₂.
• Handoff: symptom onset time, each drug with time and dose, cumulative dose, infusion rate, BP trend and urine output.
• Equipment: infusion pump, premixed infusion bags, and suction. Check the concentration on every bag and vial. Labetalol comes as 5 mg/mL vials and 1 mg/mL bags.

• Pediatrics: Safety and effectiveness of nicardipine and clevidipine are not established in children. Labetalol in children is specialist use only, dosed by weight from pediatric references. Use Weight-Based Dosing and Vital Signs.
• Pregnancy: Follow the Preeclampsia page. The severe range is SBP 160 or higher or DBP 110 or higher, and it has to persist at least 15 minutes. ACOG first-line agents are IV labetalol, IV hydralazine (5–10 mg) and oral immediate-release nifedipine. Nitroglycerin is not a BP treatment here.
• Renal Impairment: in renal impairment, nicardipine clears more slowly, so titrate gradually. Thiocyanate from nitroprusside builds up in renal impairment, so avoid it or limit how long it runs. See Nicardipine
• Patients on Beta-Blockers: Nicardipine and clevidipine do not protect against beta-blocker withdrawal. Taper the beta-blocker. Never stop it abruptly.
• Patients on Anticoagulants: for intracerebral hemorrhage on anticoagulants, use the reversal steps in Hemorrhagic Stroke.

• Error: treating a number with no organ injury behind it. Recheck, examine, and plan oral therapy with outpatient follow-up.
• Error: driving BP down too fast. Cap the first-hour fall at about 25%, and check the target for the organ at risk. A fast drop can cause ischemia in the brain, heart or kidney.
• Error: using a vasodilator before beta-blockade in suspected aortic dissection. Get the heart rate under control first.
• Error: mixing up labetalol concentrations. Drawing a volume meant for 5 mg/mL from a 1 mg/mL bag is a 5-fold error. Recount the running total at every bolus and handoff.
• Error: a nitrate for a patient with suspected right ventricular infarction, recent PDE-5 inhibitor use (sildenafil or vardenafil within 24 hours, tadalafil within 48 hours) or riociguat.
• Error: running nitroprusside at its maximum rate for more than 10 minutes, or without an arterial line. The hazards are cyanide and thiocyanate toxicity. The drug can also cause precipitous hypotension.
• Error: using a beta-blocker alone for cocaine or methamphetamine toxicity, or for suspected pheochromocytoma. Stimulants get a benzodiazepine first. Catecholamine excess gets alpha blockade.
• Error: missing a mimic. Check glucose, and look for stroke, hemorrhage and stimulant toxicity before you label the case.