Hypertensive emergency

Background

• End-organ damage d/t increased BP (generally >180/120, usually > 220/130)

Clinical Features

• Brain - Encephalopathy, seizure, ICH, ischemic stroke
• Eyes - Retinal hemorrhage, exudate, papilledema
• Heart - ACS, CHF/LV failure/pulm edema
• Aorta - Dissection
• Renal - Acute failure, hematuria, proteinuria

Diagnosis

• Chem - assess renal failure
• UA - Assess renal failure, glomerulonephritis, preeclampsia
• Troponin
• CXR - Evidence of failure, dissection
• ECG

Etiology

• Idiopathic
• Sympathomimetic drug use
• Preeclampsia
• Acute glomerulonephritis

Treatment

• Goal: Lower diastolic pressure to 105mmHg within 2-6 hours
  • Maximum initial fall in BP should not exceed 25% of presenting value
• Be careful of lowering BP in pts with CVA

By Drug

Drug	Dose	Mechanism	Pros	Cons	Notes
Nitroprusside	0.3-0.5 mcg/kg/min IV initial infusion Incr by 0.5mcg/kg/min up to 2mcg/kg/min	Arterial and veno-dilator	1. Very effective 2. Immediate onset/offset	1. Cyanide Toxicity 2. Coronary steal? 3. Incr HR	1. Avoid in liver/renal failure 2. Avoid with incr ICP 3. Avoid in pregnancy
Nitroglycerin	Start 5-100 mcg/min	Veno>arteriodilation	1. Rapid on/offset 2. Increases coronary flow	Causes Tachycardia	Drug of choice in pts w/ cardiac ischemia, LV dysfunction, or pulm edema
Labetalol	20-80mg IV bolus q10min OR 0.5-2mg/min IV infusion	Beta>alpha blocker	1. No change in HR, cerebral flow 2. Rapid onset	Avoid in COPD, CHF heart block	1. Consider in ACS 2. Consider in ischemic CVA
Esmolol	Load 250-500 mg/kg/ over 2min Infuse 50mcg/kg/min over 4min - if ineffective repeat load, increase infusion rate by  50mcg/kg/min up to 200mcg/kg/min	Beta selective	1. Rapid on/offset	Avoid in COPD, CHF bradycardia	Consider in ACS
Nicardipine	Start 5mg/h If ineffective after 15min incr in 2.5mg/hr interval up to 15mg/hr	Decreases PVR	Good for intracranial pathology	Slower onset/offset	Avoid in CHF, ACS
Phentolamine	5-10mg IV bolus q5-15min OR 0.2-5mg/min IV infusion	Alpha blocker			Used for catecholamine-induced HTN
Enalaprilat	Bolus 1.25mg over 5min q6hr, titrate at 30min intervals to max of 5mg q6hr	Decreases HR, SV, systemic arterial pressure	Does not impair cerebral flow	Variable response	1. Used in pts at risk for cerebral hypotension, CHF 2. Avoid in pregnancy

By Disease

Aortic Dissection

• Rapidly reduce sys BP to 100-120; HR 60-80 within 20min
• Avoid volume depletion
• Prevent reflex tachycardia
  • Labetolol alone
  • Nitroprusside or nicardipine AFTER metoprolol or esmolol

Pulmonary Edema

• Reduce BP by 20-30%
• Promote diuresis AFTER vasodilation

ACS

• No more than 20-30% reduction for SBP >160
• Consider NTG, B-blocker

Cocaine/Amphetamine Toxicitiy

• Benzos
• Mixed alpha + B blockade
  • Phentolamine OR nitroprusside AND beta blocker

Renal Failure

• Reduce BP by no more than 20%
• Avoid nitroprusside (renal metabolism)
• Labetalol or nicardipine

Eclampsia/Pre-eclampsia

• Goal BP <160/110
• Labetalol or nicardipine
• Magnesium

Encephalopathy

• Decrease MAP by 15-20%
  • Avoid overly aggressive lowering
• Nicardipine or labetalol

CVA

• SAH
  • See Subarachnoid Hemorrhage (SAH)
• ICH
  • If e/o incr ICP: target MAP = 130
  • If no e/o incr ICP: target MAP = 110
  • Labetalol or nicardipine or esmolol
• Ischemic
  • If fibrinolytic tx planned, tx if >185-110
  • If not planned, tx if >220-120
  • Labetalol or NTG or nicardipine

Pheochromocytoma

• Phentolamine OR (nitroprusside AND beta blocker)

See Also

• Hypertension (Main)

Source

• Tintinalli
• UpToDate