Table of contents
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Introduction
- Severe hypertension defined as:
- > 180/120 (sBP or dBP)
- Assess for evidence of end-organ damage (separates urgency from emergencies)
- Hypertensive Urgency: Severe hypertension without evidence of end-organ damage
- Manage with oral medications to reduce BP to ≤ 160/100 (over several days)
- No URGENT IV therapy needed
- Hypertensive Emergency
- End-organ damage found
- Use IV medication to lower blood pressure (i.e. by 15-25%)
(Malignant Hypertension)
- Sufficient elevation of BP (undefined, usually >200/140) to cause:
- Papilledema
- Vascular Damage (retinal hemorrhages, bulging discs, mental status change, increasing creatinine)
Hypertensive Urgency
- Severe HTN (>180/120) with no symptoms other than a headache
Hypertensive Emergency
- Severe HTN (no defined number) + acute end-organ damage / dysfunction.
- Examples of end-organ dysfunction:
- Malignant HTN + papilledema
- Cerebrovascular
- Hypertensive encepalopathy
- CVA with severe hypertension
- Intracerebral hemorrhage
- SAH
- Cardiac
- Aortic dissection
- LV failure (new onset CHF)
- MI
- Renal Failure
General Ma nagement
- Goal is to assess for end-organ damage
- Physical exam
- Neurologic exam (mental status, visual fields, acuity)
- Volume status (fluid overload?)
- Aortic dissection (symmetry of pulses, bilateral blood pressures)
- Investigations:
- Electrolytes, BUN, creatinine, CBC, CK/troponin (ischemia signs?), urinalysis, renal injury, drug levels (cocaine, amphetamines)
- EKG, CXR
- Brain imaging if mental status decreased or neuro findings.
- CT Angio if concerned of aortic dissection.
- Management:
- Hypertensive Urgency: ORAL MEDICATIONS (see other sections)
- Hypertensive Emergency: IV MEDICATIONS (keep reading)
- Short-acting IV antihypertensive infusions to limit end-organ damage.
- First line: Sodium nitroprusside (controlled BP reduction, continuous infusion, neec surveillance)
- Second line: boluses of: labetalol, phentolamine, nitroglycerin, hydralazine.
- Short-acting IV antihypertensive infusions to limit end-organ damage.
- Should not be lowered to normal, or lowered any further than to stop acute end-organ damage.
- Generally do not reduce MAP by >25% (sometimes diastolic of 100 (whichever is higher)) in 1 hour.
- limit of cerebral BP autoregulation. if lower >50% then cerebral ischemia insues.
- If new focal deficits, stop antihypertensives!
- Generally do not reduce MAP by >25% (sometimes diastolic of 100 (whichever is higher)) in 1 hour.
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Table below shows options for hypertensive crisis
IV Antihypertensive Agents for Hypertensive Crises
Agent (Class) | Dose (Delivery) | Onset | Duration | Notes | Adverse Effects (All Cause Hypotension) |
---|---|---|---|---|---|
Nitroprusside (vasodilator) | 0.25-10 µg/kg/min (IV) | Immediate | 1-10 min | Easy to titrate; often first choice for acute situations | Risk of cyanide toxicity |
Nitroglycerin (vasodilator) | 0.25-5 µg/kg/min (IV) | Immediate | 3-5 min | Used for myocardial ischemia; tolerance may develop | Headache, bradycardia |
Hydralazine (vasodilator) | 5-20 mg every 4-6 hours (IV) | 1-5 min | 1-4 hours | Safe in pregnancy | Nausea, headache, tachycardia |
Labetalol (α- and β-blocker) | 20 mg IV over 2min then infuse 1-2 mg/min (max dose = 300mg) or 20mg every 10 min | 2-5 min | 3-6 hours | Can be switched to oral | Bradycardia, heart block, nausea, bronchospasm |
Enalaprilat (ACE inhibitor) | 1.25 mg every 6 hours (IV) | 15 min | 6-12 hours | Can be switched to oral; good for left ventricular failure | Prolonged hypotension |
Nicardipine (calcium channel blocker) | 5 mg/hour titrated up to 15 mg/hour (IV) | 1-5 min | 3-6 hours | Often used for patients with stroke | Myocardial ischemia, tachycardia, headache |
Fenoldopam (dopamine agonist) | 0.03-0.1 µg/kg/min (IV) | 10 min | 1 hour | Can be titrated up slowly to 1.6 µg/kg/min; may be protective of kidneys | Flushing, headache, nausea, tachycardia, possibly increased myocardial ischemia |
Phentolamine (α-blocker) | 5-20 mg (IV) | 15-20 min | 30-45 min | Used for diagnosis of and surgery for pheochromocytoma | Nausea, arrhythmia |
Esmolol | 500 ug/kg bolus + 50 ug/kg/min incr. infusion by 25 q5m to target heart rate | - For heart rate control |
Source: MKSAP16
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