Cardiology · Emergency Medicine
Hypertensive Emergency
Emergency vs Urgency · Target BP Reduction · IV Drug Selection · End-Organ Damage Assessment
📋 Emergency vs Urgency — Key Distinction
🚨 Hypertensive Emergency
SBP typically >180 mmHg and/or DBP >120 mmHg
WITH acute end-organ damage (see below)
Requires IV therapy in monitored setting (ICU/HDU)
BP reduction: ↓ 20–25% MAP in first hour, then gradual
Examples: hypertensive encephalopathy, aortic dissection, eclampsia, ACS, pulmonary edema
⚠️ Hypertensive Urgency
SBP typically >180 mmHg and/or DBP >120 mmHg
WITHOUT acute end-organ damage
Can be treated with oral agents
Gradual reduction over 24–48 hours
Reassess compliance, medications, secondary causes
🔬 End-Organ Damage Assessment
Neurological
Hypertensive encephalopathy (confusion, seizures)
Acute ischemic or hemorrhagic stroke
Papilledema on fundoscopy
Headache, visual changes, nausea/vomiting
Cardiovascular / Renal
Acute coronary syndrome / Acute HF / APO
Aortic dissection (tear, pulse differential)
Acute kidney injury (↑Cr, proteinuria, hematuria)
Microangiopathic hemolytic anemia (MAHA)
💊 IV Antihypertensive Drug Selection
DrugDose (IV)Onset / DurationPreferred ForAvoid If
Labetalol
α+β blocker
20 mg IV bolus q10min
or 0.5–2 mg/min infusion
5 min / 3–6 h HTN encephalopathy, ACS, aortic dissection, eclampsia Acute HF, asthma, bradycardia, AV block
Nicardipine
CCB (DHP)
5 mg/h; titrate 2.5 mg/h q5–15min
max 15 mg/h
5–10 min / 1–4 h Stroke, SAH, post-op HTN, AKI, eclampsia Acute HF with decompensation
Clevidipine
CCB (ultra-short)
1–2 mg/h; double q90sec
max 32 mg/h
2–4 min / 5–15 min Perioperative, ICU, rapid titration needed Egg/soy allergy, lipid metabolism disorders
Hydralazine
Direct vasodilator
10–20 mg IV over 20 min
repeat q4–6h PRN
10–30 min / 3–8 h Eclampsia, pregnancy-related HTN Aortic dissection, ischemic heart disease
Sodium Nitroprusside
Vasodilator
0.25–0.5 mcg/kg/min
max 10 mcg/kg/min (short-term)
Seconds / 1–2 min Hypertensive crisis — most potent, immediate effect Renal/hepatic failure (cyanide toxicity), ↑ICP, pregnancy
Esmolol
β-1 blocker
500 mcg/kg bolus → 50–300 mcg/kg/min 1–2 min / 10–20 min Aortic dissection (with nitroprusside), periop tachycardia Asthma, bradycardia, heart block, decompensated HF
Phentolamine
α-blocker
2.5–5 mg IV bolus q5–15min
or 0.5–1 mg/min infusion
1–2 min / 10–15 min Pheochromocytoma crisis, cocaine-induced HTN Renal failure, coronary artery disease
🎯 BP Reduction Targets by Condition
Specific Scenarios
Hypertensive encephalopathy: ↓ MAP by 20–25% in 1h
Aortic dissection (Type A/B): SBP <120 mmHg within 20 min
Ischemic stroke (no lytic): BP <220/120 mmHg (conservative)
Ischemic stroke (pre-lytic): <185/110 mmHg before tPA
Hemorrhagic stroke: SBP <140 mmHg (ATACH-2 / INTERACT2)
Eclampsia: SBP <160, DBP <110 mmHg
⚠️ Critical Warnings
Never reduce BP too quickly — risk of ischemic stroke, AKI, MI
Autoregulation impaired in chronic HTN — gradual reduction essential
Aortic dissection: heart rate target <60 bpm (use esmolol)
Eclampsia: also give MgSO₄ 4g IV loading dose
Avoid sublingual nifedipine — uncontrolled rapid BP drop
CCM Notes · FOAMed · Critical Care Clinical Reference
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Based on AHA/ESC Hypertension Guidelines 2023
Educational use only