279.1 🎓 醫孞生版

279.1.0.1 📌 䞀頁重點

279.1.0.1.1 Definitions
279.1.0.1.1.1 Hypertensive Emergency
  • BP > 180/120 mmHg PLUS
  • Acute end-organ damage:
    • Hypertensive encephalopathy
    • Acute ischemic stroke (AIS)
    • Hemorrhagic stroke
    • Acute MI / unstable angina
    • Acute pulmonary edema (HFrEF or HFpEF)
    • Aortic dissection
    • Acute kidney injury
    • Eclampsia / severe preeclampsia
    • Hypertensive retinopathy (grade III/IV — hemorrhages, exudates, papilledema)
    • Microangiopathic hemolytic anemia (MAHA)
  • Management: ICU, IV agents, goal-directed reduction
279.1.0.1.1.2 Hypertensive Urgency
  • BP > 180/120 mmHg WITHOUT acute end-organ damage
  • Asymptomatic or mild headache, anxiety
  • Management: oral agents, gradual reduction over 24-48h, outpatient F/U
279.1.0.1.1.3 “Malignant HTN” (Older Term)
  • Severe HTN with retinal hemorrhages, exudates, papilledema (KWB grade III/IV)
  • Often with MAHA, AKI
  • Subset of emergency
279.1.0.1.2 Epidemiology
  • 1-2% of HTN patients yearly have a hypertensive crisis
  • ~ 25% are emergencies
  • Higher in African Americans, low SES, non-adherent
  • Common precipitants: medication non-adherence, drug-induced (cocaine, amphetamines), secondary HTN, AKI
279.1.0.1.3 Pathophysiology
279.1.0.1.3.1 Pressure-Natriuresis Curve Shift
  • Chronically HTN patients shift autoregulation curve
  • Acute fall in BP risks hypoperfusion of brain/heart/kidney
  • Hence “gradual reduction”
279.1.0.1.3.2 Endothelial Injury
  • BP > critical threshold → endothelial damage → microvascular leak, platelet activation, fibrin deposition
  • MAHA can develop
  • Cerebral edema, papilledema
279.1.0.1.3.3 RAAS Surge
  • Renal ischemia → renin → Ang II surge → further BP elevation
  • Vicious cycle
279.1.0.1.4 Clinical Assessment
279.1.0.1.4.1 History
  • Duration, severity of HTN
  • Adherence to medications
  • Drug use (cocaine, amphetamines, MAOIs, sympathomimetics)
  • Symptoms suggesting end-organ damage:
    • Neurologic: HA, confusion, vision change, seizure, focal weakness
    • Cardiac: chest pain, dyspnea, orthopnea
    • Renal: anuria, hematuria, flank pain
    • Vascular: tearing chest/back pain (dissection)
  • Pregnancy
279.1.0.1.4.2 Physical
  • BP in BOTH arms (dissection!)
  • Heart rate, rhythm
  • Cardiac auscultation (S3, S4, murmurs, friction rub)
  • Lung auscultation (rales, wheezing)
  • Neurologic exam
  • Fundoscopy (papilledema, hemorrhages, exudates, AV nicking)
  • Abdominal exam (bruits, pulsatile mass)
  • Femoral pulses
279.1.0.1.4.3 Investigations
  • Labs: CBC, BMP/eGFR, troponin, BNP, UA, urine drug screen, peripheral smear (MAHA)
  • ECG: ischemia, LVH, arrhythmia
  • CXR: pulmonary edema, widened mediastinum
  • Echo: LVH, LV function, dissection (TEE)
  • CT angio: aorta, head (stroke), pulmonary
  • MRI: hypertensive encephalopathy (PRES — posterior reversible encephalopathy syndrome)
279.1.0.1.5 IV Agents for Emergency
279.1.0.1.5.1 Labetalol
  • α/β-blocker
  • IV bolus 10-20 mg, then 20-80 mg every 10 min OR infusion 1-2 mg/min
  • First-line for most: stroke, encephalopathy, pregnancy, post-cardiac surgery
  • Avoid: HF, severe asthma, bradycardia
279.1.0.1.5.2 Nicardipine
  • DHP CCB
  • Infusion 5-15 mg/h
  • Good for: encephalopathy, stroke (esp ICH), aortic dissection (with β-blocker)
  • Side effects: reflex tachycardia, headache
279.1.0.1.5.3 Clevidipine
  • DHP CCB, ultra-short-acting
  • Infusion 1-32 mg/h
  • Good for: cardiac surgery, rapid titration
  • Lipid emulsion (concern in pancreatitis, egg/soy allergy)
279.1.0.1.5.4 Nitroprusside
  • Direct NO donor (arterial + venous)
  • Infusion 0.25-10 ÎŒg/kg/min
  • Fast on/off
  • Use cautiously: cyanide toxicity (avoid > 3 ÎŒg/kg/min, AKI, prolonged use)
  • Good for: acute HF + emergency
  • Avoid in: AIS, pregnancy
279.1.0.1.5.5 Nitroglycerin
  • Venous > arterial vasodilator
  • 5-200 ÎŒg/min
  • Good for: acute coronary syndrome, pulmonary edema, RV dysfunction (cautious)
  • Less for HTN alone
279.1.0.1.5.6 Esmolol
  • β1-selective, ultra-short-acting
  • 500 ÎŒg/kg bolus, then 50-300 ÎŒg/kg/min
  • Excellent for: aortic dissection (HR control), post-op, tachyarrhythmia + HTN
  • Easy titration
279.1.0.1.5.7 Enalaprilat
  • IV ACEi
  • 1.25-5 mg every 6h
  • HF emergency
  • Avoid in pregnancy, bilateral RAS
279.1.0.1.5.8 Hydralazine
  • Direct vasodilator
  • 10-20 mg IV every 4-6h
  • Pregnancy, eclampsia
  • Less predictable; reflex tachy
279.1.0.1.5.9 Fenoldopam
  • Dopamine D1 agonist
  • 0.1-0.6 ÎŒg/kg/min
  • Renal vasodilation; good for AKI + HTN
  • Avoid in glaucoma
279.1.0.1.6 Treatment Targets by Condition
279.1.0.1.6.1 Hypertensive Encephalopathy / PRES
  • ↓ MAP 25% in 1 hour
  • Then 160/100 in next 23 hours
  • IV labetalol or nicardipine
279.1.0.1.6.2 Acute Ischemic Stroke (AIS)
  • Permissive HTN ≀ 220/120 if NOT receiving thrombolysis
  • < 185/110 before, < 180/105 after thrombolysis or thrombectomy
  • IV labetalol or nicardipine
  • Hold home meds initially
279.1.0.1.6.3 Acute Hemorrhagic Stroke (ICH)
  • Target SBP < 140 within 1-6 hours (INTERACT-2, ATACH-II)
  • IV nicardipine preferred
  • Avoid drops > 90 mmHg from baseline
279.1.0.1.6.4 Acute MI / Unstable Angina
  • Goal < 140 / 90 within hours
  • IV NTG + β-blocker (esmolol or metoprolol)
  • Avoid hydralazine (reflex tachy → ischemia)
279.1.0.1.6.5 Acute Pulmonary Edema
  • IV NTG (preload reduction)
  • IV loop diuretic
  • ACEi (consider enalaprilat)
  • Avoid β-blocker in active failure (use carvedilol later when stable)
279.1.0.1.6.6 Aortic Dissection
  • SBP < 120 + HR < 60 in 10 min
  • IV esmolol first (HR control) → then add vasodilator (nicardipine or nitroprusside)
  • Avoid pure vasodilator alone (reflex tachy worsens dissection)
  • Type A (ascending): EMERGENCY surgery
  • Type B (descending): medical management ± TEVAR
279.1.0.1.6.7 Eclampsia / Severe Preeclampsia
  • SBP < 160, DBP < 110 within minutes
  • IV labetalol OR IV hydralazine OR oral nifedipine
  • Magnesium sulfate for seizure prophylaxis (4-6 g IV load, 1-2 g/h)
  • Definitive: delivery
279.1.0.1.6.8 Pheochromocytoma Crisis
  • Phentolamine IV (α-blocker)
  • Nicardipine, nitroprusside
  • AVOID β-blocker alone (unopposed α)
  • Add β after α-blockade
279.1.0.1.6.9 Cocaine / Sympathomimetic HTN
  • IV benzodiazepine first
  • Nicardipine, nitroglycerin
  • AVOID pure β-blocker (unopposed α)
  • Phentolamine OK
279.1.0.1.7 Hypertensive Urgency
279.1.0.1.7.1 Definition
  • BP > 180/120 WITHOUT acute end-organ damage
  • Often asymptomatic / mild HA
279.1.0.1.7.2 Management
  • Oral agents, GRADUAL reduction over 24-48h
  • Restart home meds + add one
  • Options:
    • Captopril 25 mg PO (short half-life)
    • Labetalol 200-400 mg PO
    • Clonidine 0.1-0.2 mg PO (rebound risk)
    • Amlodipine 5-10 mg
  • AVOID rapid drop (can cause stroke, MI, AKI)
  • Watch over 4-6 hours; discharge if BP improves
  • Outpatient F/U 1-7 days
  • Identify precipitating factor
279.1.0.1.7.3 Avoid: Old Practice
  • Sublingual nifedipine = NO (unpredictable, harmful)
  • IV agents not needed if no end-organ damage
279.1.0.1.8 Hypertensive Retinopathy (Keith-Wagener-Barker)
  • Grade I: arteriolar narrowing, copper wiring (asymptomatic)
  • Grade II: AV nicking, silver wiring (asymptomatic)
  • Grade III: hemorrhages, exudates, cotton wool spots (suggests acute injury)
  • Grade IV: papilledema (malignant HTN)
279.1.0.1.8.1 Significance
  • III + IV = emergency
  • Reversible with BP control
279.1.0.1.9 Special Situations
279.1.0.1.9.1 MAHA + AKI in HTN
  • Thrombotic microangiopathy from severe HTN
  • Schistocytes on peripheral smear
  • ↓ haptoglobin, ↑ LDH, ↑ retics
  • Need to rule out TTP/HUS (ADAMTS13)
  • Treat BP urgently
279.1.0.1.9.2 Post-Op HTN
  • Surgical pain, fluid shifts, withdrawal of home meds
  • IV clevidipine or nicardipine
  • Restart oral meds
279.1.0.1.9.3 Withdrawal HTN
  • Clonidine withdrawal (rebound)
  • β-blocker withdrawal
  • Use clonidine patch or restart agent

279.1.0.2 🩺 床邊速查

  • Emergency = BP > 180/120 + end-organ damage → ICU + IV
  • Urgency = BP > 180/120 NO end-organ damage → oral, F/U
  • First hour target: SBP ↓ 25% (except dissection → < 120 in 10 min; ICH → < 140 in 6h)
  • Aortic dissection: esmolol FIRST (HR), then nicardipine
  • Eclampsia: labetalol/hydralazine/nifedipine + magnesium
  • AIS: permissive HTN ≀ 220/120 (or < 185/110 before lysis)
  • NO sublingual nifedipine for urgency