Hypertensive Emergencies

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Hypertensive Emergencies

• by Paul Rega, M.D., FACEP
• OMNI Health Services

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Case 1

• 65-year-old ?
• SOB
• Rales
• BP 240/168

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Case 2

• 75-year-old ?
• Elective AAA
• Increasing abdominal pain
• BP 240/168

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Case 3

• 33-year-old ?
• Cocaine intoxication
• BP 240/168

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Case 4

• 76-year-old ?
• Aneurysmal SAH
• BP 240/168

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Definition

• Hypertensive emergency Severe elevation in BP
  thats complicated by evidence of progressive
  target organ dysfunction.
• Reduction indicated to prevent or limit target
  organ damage.

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Pathophysiology

• Poorly understood
• Varies with etiology
• Rate of rise Important in pathology
• There is a sudden increase in systemic vascular
  resistance 2 circulating humoral
  vasoconstrictors
• Loss of an organs auto-regulation capability
  occurs
• Target organ dysfunction

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Whats Important

• Not the degree of BP elevation but
• The clinical status of the patient that defines
  an emergency.
• BP alone does not determine an emergency.
• The degree of target organ involvement that
  determines the rapidity with which the BP should
  be lowered.

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Types

• Aortic dissection
• Pulmonary edema
• MI
• Acute coronary syndrome
• Acute renal failure
• HELLP syndrome
• Severe pre-eclampsia
• Eclampsia

• Hypertensive encephalopathy
• Subarachnoid hemorrhage
• Intracranial hemorrhage
• Acute ischemic stroke
• Sympathetic crisis

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Target Organ Damage Associated with Hypertensive
Emergencies

• Cerebral infarction 24.5 of cases
• Hypertensive encephalopathy 16.3
• Acute decompensated heart failure 14.3
• ACS 12.0
• ICH 4.5
• Aortic dissection 2.0

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1 Study

• Diastolic BP gt 120 mm Hg
• Pulmonary edema 36.8
• Cerebral infarction 24.5
• Encephalopathy 16.3
• MI 12
• SAH 4.5
• Eclampsia 4.5
• Aortic dissection 2

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Goal

• Not to obtain a normal BP
• To achieve a progressive, controlled reduction
  in BP
• To minimize risk of hypoperfusion in cerebral,
  coronary, and renovascular beds.

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Risk of Rapid BP Reduction

• Acute renal deterioration
• Ischemic cardiac event
• Ischemic cerebral event
• Retinal artery occlusion (blindness)

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Labetalol

• ß-blocker weak a-1 effects
• Without reflex tachycardia
• Commonly used
• Broad applications
• Exceptions
• Cocaine intoxication
• Decompensated heart failure
• Bolus 10-20mg IV over 2 min.
• 40-80 mg _at_ 10-min intervals up to 300 mg total.
• Check BP 5 10 min. after bolus
• Infusion 2mg/min and titrate to response up to
  300 mg.
• Effect 2-5 min. peaks _at_ 15 min and lasts 2-4
  hours.
• Avoid in
• Bradycardia, heart block, bronchospasm, CHF.

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Metoprolol

• Indication Acute CAS
• 5 mg q 5-15 min up to 15 mg.

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Esmolol

• Ultra-short, cardioselective ß-blocker.
• ß1 receptors chiefly in cardiac muscle
• Higher doses ß2 receptors in bronchi and
  vascular muscle elsewhere
• Loading dose 250-500mcg/kg IV over 1-3 min. then
• Infusion 50 mcg/kg/min over 4 min.
• May repeat loading dose and increase infusion
  rate in increments of 50 mcg/kg/min up to 4
  times.
• Effect Within 60 sec. lasts 10-20 minutes.
• ½-life 8 min.
• Avoid in
• Bradycardia, heart block, bronchospasm, CHF.

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Nicardipine

• 2nd-generation calcium channel blocker (inhibits
  influx of Ca ions into cardiac/vascular smooth
  muscle)
• Selective for cerebral and coronary arteries
• Dose-dependent decrease in systemic vascular
  resistance
• Continuous infusion 5mg/hr
• May increase by 2.5 mg/hr q 15 min. until target
  pressure or dose of 15 mg/hr is reached.
• Onset 5-10 min.
• Duration 1-4 hours.
• Safe in neurologic hypertensive emergencies
• Doesnt increase ICP
• Favorable effect on myocardial oxygen balance
• Avoid with IV ß-blockers
• Caution in CHF, aortic stenosis.

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Clevidipine

• 3rd-generation calcium channel blocker
• Ultra-short
• Arteriolar vasodilating properties
• Cardiac surgery
• May have emergency applications elsewhere
• ½-life lt 1 min.

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Nifedipine

• Discouraged in hypertensive emergencies
• Can expand zone of ischemia/infarction
• May be used in patients with pre-eclampsia
• 10 mg PO

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Nitroglycerin

• Venodilator
• Arteriodilator at high doses
• Reduces preload, CO, cardiac workload
• First-line in CHF CAS
• Continuous infusion
• 5 mcg/min, increase by 5 q 3-5 min up to 20
  mcg/min
• Then by 10 mcg/min q 3-5 min. up to 200 mcg/min.
• Onset 2 min.
• Duration 1 hour
• Avoid Renal/cerebral hypoperfusion, Viagra.

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Nitroprusside

• Arterio- Venodilator
• Decreases preload afterload
• Potential, as a general vasodilator, to increase
  ICP
• Acta Neurochir 1891 58203-211
• Continuous infusion
• 0.3-0.5 mcg/kg/min, increase by 0.5 mcg/kg/min
  and titrate.
• Onset Seconds
• Duration 1-2 minutes
• Caution gt2 mcg/kg/min may lead to CN toxicity
• Avoid Renal/hepatic failure, neurovascular
  emergencies, increased ICP.
• Recommended when all else fails.
• May be added to other anti-hypertensives

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Phentolamine

• a-1 a-2 blocker
• Bolus
• 5-20 mg IV q 5 min.
• Infusion
• 0.2-0.5 mg/min
• Indications
• Cocaine intoxication
• Pheochromocytoma
• May induce
• MI
• CVA

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Fenoldopam

• Dopamine-1 agonist
• Infusion 0.1 mcg/kg/min and titrate q 15 min.
• Range 0.1 1.6 mcg/kg/min
• Onset 5 min.
• Peak 15 min.
• Duration 30-60 min.
• Improves Cr clearance urine flow
• Applications
• Renal/neurologic hypertensive emergencies
• S.E. Flushing, dizziness, vomiting

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Enalaprilat

• ACE inhibitor
• Only 1 IV
• Application
• CHF
• Acute CAS
• Test dose 0.625 mg
• Hypotension common with 1st dose
• Bolus 1.25 mg over 5 min q 4-6 h
• Onset Within 15 min.
• Maximum effect 1-4 hours
• Avoid in pregnancy, angioedema

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Choices
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SAH, Intracranial Hemorrhage

• SBP 210 MAP 150
• Well? Now what?

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SAH, ICH

• Labetalol
• Nicardipine
• Esmolol
• Caution Must maintain CPP while preventing
  rebleeding
• SBP lt 160 mm Hg (MAP lt 130 mm Hg)
• SBP gt 120 mm Hg to maintain CPP
• Evidence of increased ICP Maintain MAP _at_ 130 mm
  Hg

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Acute Ischemic Stroke

• SBP 210 MAP 150
• Yes?

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Acute Ischemic Stroke

• Labetalol
• Nicardipine
• If fibrinolytic therapy planned
• Treat if gt185/110 mm Hg
• Must avoid worsening ischemia by dropping BP too
  much
• No more than 10-15 in first 24 hours

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Cocaine/Amphetamine

• SBP 210 MAP 150
• Youve got a screaming-meamie on your hands.

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Cocaine/Amphetamine

• Benzodiazepine
• May be all you need
• Nitroglycerin
• Phentolamine
• No ß-blockers like labetalol
• a-adrenergic effect is unopposed
• Vasoconstriction
• Paradoxical increase in BP

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Acute Aortic Dissection

• SBP 210 MAP 150
• The pain is all out of proportion to what he
  looks like. Cant lay still. Help him!!!!

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Acute Aortic Dissection

• Analgesia (e.g. Morphine)
• Labetalol drip
• Esmolol bolus drip
• Verapamil/diltiazem OK if ß-blocker cant be
  used.
• Nicardipine drip (after ß-blocker)
• Nitroprusside drip (after ß-blocker)
• No ß-blocker first will create tachycardia and
  increase wall stress.
• Mainstay of therapy ß-blocker vasodilator
• Goals
• SBP 100-120mm Hg
• HR lt 60
• Reduction of shear forces by reduction of BP HR

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Acute Pulmonary Edema

• SBP 210 MAP 150
• The gurgles and bubbles and rales are loud enough
  to be heard over drunken babble at Put-In-Bay.

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Acute Pulmonary Edema

• Nitroglycerin SL, topical, drip.
• Dilates capacitance vessels _at_ low doses
• Dilates arterioles _at_ high doses
• Enalaprilat
• Lasix
• Lower survival rate with diuretics alone
• Nitroprusside drip
• Goals
• Reduce BP by 20-30
• Vasodilatation
• Diuresis

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Severe Pre-eclampsia, Eclampsia, HELLP

• SBP 210 MAP 150
• Shake, rattle, and roll.

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Severe Pre-eclampsia, Eclampsia, HELLP

• MgSo4 Seizure control
• Labetalol bolus
• Nifedipine PO
• Nicardipine may be better if cant take PO
• Hydralazine not recommended
• Unpredictable response
• ACEI
• Fetal abnormalities (e.g. Voting Republican this
  year)
• Goals
• lt160/110 mm Hg
• lt150/100 mm Hg if platelets lt 100,000 mm³

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References

• Cline DM, Amin A. Drug Treatment for
  Hypertensive Emergencies. Emergency Medicine
  Cardiac Research and Education Group. 2008
  11-9.
• Dubow D. Hypertensive Emergencies in Emergency
  Medicine (4th edition) Cline DM, Ma OJ, et al
  (editors) McGraw-Hill, New York. 1996.
• Vidt D. Hypertensive Crises Emergencies
  Urgencies. www.clevelandclinicmeded.com/medicalpu
  bs/diseasemanagement/nephrology/crises/crises.htm.
  Accessed 5/30/08

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References

• McCowan C. Hypertensive Emergencies.
  wwwemedicine.com/emerg/TOPIC267.HTM. accessed
  5/30/08.
• Pancioli AM, Kasner SE. Hypertension Management
  in Acute Neurovascular Emergencies. Emergency
  Medicine Cardiac Research and Education Group.
  2007 13-21.
• Hollander JE, Chang AM. Management of
  Hypertensive Emergencies in the Emergency
  Department. Emergency Medicine Cardiac Research
  and Education Group. 2007 21-26.