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Hypertensive Emergencies, Emergency Medicine

Basics

Description

- End-organ ischemia: - Renewed release of vasoconstrictors - Worsened by pressure natriuresis - Triggers a vicious cycle

- Endocrine: - Pheochromocytoma - Cushing syndrome - Primary hyperaldosteronism - Renin-secreting tumor

- Inquire about: - Use of any prescribed and OTC medication - Duration and control of pre-existing HTN - Details of antihypertensive therapy - Comorbid conditions (obesity, CAD, DM) - Recreational drug use

- BP measured in both arms - Assess for end-organ compromise: - Neurologic: - Level of consciousness - Visual fields - Focal motor/sensory deficits

- Standard hospital protocols for chest pain - BUN, creatinine - Electrolytes - Hypokalemia present in primary mineralocorticoid excess

- Hypertensive urgency: - No need to treat, but close follow-up - Use oral agents only - Give any missed home dose - Goal: Lower the BP gradually over 24-48 hr

- Ischemic stroke: - CPP = MAP - ICP - Decreased CPP from hypotension (low MAP) or cerebral edema (high ICP) may extend infarct - Treat only SBP >220 mm Hg or DBP >120 mm Hg - Lytic candidates should have BP lowered to <185/110 mm Hg - Goal: MAP lowered by no more than 15-20%, DBP not <100-110 mm Hg in first 24 hr - Goal post tPA: BP <180/105 mm Hg - Drug of choice: Nicardipine, clevidipine, or labetalol

- Preeclampsia: - Definition: SBP >140 or DBP >90 mm Hg with proteinuria (>300 mg/24 hr or a urine protein/creatinine >0.3 or dipstick 1+) - Occurs >20 wk gestation - 4 wk postpartum - Headache, vision changes, peripheral edema, RUQ pain - Complications: Eclampsia, HELLP - Goal: SBP 130-150 mm Hg and DBP 80-100 mm Hg - Drug of choice: Labetalol, nicardipine, hydralazine, magnesium - Consult Obstetrics

- Clevidipine: - 3rd generation dihydropyridine CCB - Onset 2-4 min, duration 5-15 min - Elimination independent of liver/renal function - Avoid in allergies to soy or egg products, defective lipid metabolism, AFib

- Nitroglycerin: - Venous > arteriolar dilation - Onset 2-5 min, duration 10-20 min - Perfuses coronaries, decreasing ischemia - Causes reflex tachycardia, tachyphylaxis, methemoglobinemia

- Nitroprusside: - Short-acting arterial and venous dilator - Onset 3 s, duration 1-2 min - Complications: - Reflex tachycardia, "coronary steal"пїЅ, increase ICP - Cyanide toxicity after prolonged use

- Hydralazine: - Arteriolar dilator - Onset 5-15 min, duration 3-10 hr - Hypotensive effect may be less predictable - Safe in pregnancy

- Fenoldopam: - Selective postsynaptic dopaminergic receptor agonist (DA1) - Onset 5-15 min, duration 1-4 hr - No reflex tachycardia - Maintains renal perfusion - Avoid in: Glaucoma

  • Hypertensive crisis:Severely elevated BP defined by a SBP >179 mm Hg or a DBP >109 mm Hg
  • Hypertensive urgency:Severely elevated BP without end-organ damage
  • Hypertensive emergency:Severely elevated BP associated with acute end-organ damage
  • Loss of autoregulation of blood flow in hypertensive emergency:Arterioles vasoconstrict to counter pressureHigh pressures overwhelm arterioles and endothelial damage occursEndothelial injury leads to increase permeability, activation of the coagulation cascade and platelets, and deposition of fibrin
  • Activation of the renin-angiotensin system and the sympathetic nervous system:Leads to further vasoconstriction and production of proinflammatory cytokines
  • End-organ ischemia:Renewed release of vasoconstrictorsWorsened by pressure natriuresisTriggers a vicious cycle
  • Organs affected:Brain (encephalopathy, CVA, ICH)Retina (hemorrhage, papilledema)Heart (MI, aortic dissection, acute HF)Kidneys (acute renal failure)Placenta (preeclampsia/eclampsia)

Etiology

  • Essential HTN
  • Renal:Vascular diseaseParenchymal disease
  • Coarctation of the aorta
  • CNS disorders:Head traumaCVA/ICHBrain tumorSpinal cord injury
  • Endocrine:PheochromocytomaCushing syndromePrimary hyperaldosteronismRenin-secreting tumor
  • Drugs:Cocaine, phencyclidine, amphetaminesErythropoietin, tacrolimus, cyclosporine, corticosteroids, oral contraceptivesMAOI interactionsAntihypertensive medication withdrawalLead intoxication
  • Autonomic hyperreactivity:Guillain-Barr пїЅ syndromeAcute intermittent porphyria
  • Postop pain and/or anesthesia complications
  • Pregnancy related:

Diagnosis

Signs and Symptoms

History

  • Inquire about:Use of any prescribed and OTC medicationDuration and control of pre-existing HTNDetails of antihypertensive therapyComorbid conditions (obesity, CAD, DM)Recreational drug use
  • Assess for end-organ compromise in decreasing order of frequency:DyspneaChest painHeadacheAltered mental status/confusionFocal neurologic symptoms

Physical Exam

  • BP measured in both arms
  • Assess for end-organ compromise:Neurologic:Level of consciousnessVisual fieldsFocal motor/sensory deficitsOphthalmologic:Funduscopic exam (retinal hemorrhages, papilledema)Cardiovascular:Elevated JVPLung cracklesAortic insufficiency murmurS3Asymmetrical pulses

Essential Workup

  • 12-lead EKG:Ischemic changes, LV hypertrophy
  • Assess kidney functionAcute renal failure may be asymptomatic

Diagnosis Tests & Interpretation

Lab

  • CBCAnemia and thrombocytopenia are present in thrombotic microangiopathy
  • Standard hospital protocols for chest pain
  • BUN, creatinine
  • ElectrolytesHypokalemia present in primary mineralocorticoid excess
  • Urinalysis:Proteinuria, hematuria, and casts
  • Urine toxicology screen:If recreational drugs are suspected
  • HCG

Imaging

  • Chest x-ray:If cardiopulmonary symptoms are present
  • Head CT:If headache, confusion, neurologic findings
  • CTA chest and abdomen:If concern for aortic dissection

Diagnostic Procedures/Surgery

  • Arterial line
  • Lumbar puncture:Exclude subarachnoid hemorrhage

Differential Diagnosis

  • Acute coronary syndrome (ACS)
  • Acute heart failure (AHF)
  • Aortic dissection
  • Intracerebral hemorrhage (ICH)
  • CVA (ischemic or hemorrhagic)
  • Preeclampsia/eclampsia
  • Withdrawal syndromes:β-blockersClonidine (central О±2-agonist)
  • States of catecholamine excess:PheochromocytomaCocaine/sympathomimetic drug intoxicationTyramine ingestion when on MAOIs

Treatment

Pre-Hospital

  • ABCs
  • Consider gentle BP reduction.

Initial Stabilization/Therapy

  • ABC, cardiac monitoring, pulse oximetry
  • Oxygen administration
  • IV access

Ed Treatment/Procedures

  • Hypertensive urgency:No need to treat, but close follow-upUse oral agents onlyGive any missed home doseGoal: Lower the BP gradually over 24-48 hr
  • Hypertensive emergency:Treat end-organ damage, not absolute BPReduce MAP by ≤20-25% in the 1st hrGoal: Systolic ~160 mm Hg, diastolic ~100 mm Hg in 2-6 hrOnce BP stable with IV therapy, transition to oral therapy within 6-12 hrMore gradual reduction recommended in:Acute ongoing injury to CNSMore rapid reduction recommended in:
  • Hypertensive encephalopathy:Goal: MAP lowered by max. 20% or to DBP 100-110 mm Hg within 1st hr then gradual reduction in BP to normal over 48-72 hrDrug of choice: Nicardipine, clevidipine, or labetalol
  • Ischemic stroke:CPP = MAP - ICPDecreased CPP from hypotension (low MAP) or cerebral edema (high ICP) may extend infarctTreat only SBP >220 mm Hg or DBP >120 mm HgLytic candidates should have BP lowered to <185/110 mm HgGoal: MAP lowered by no more than 15-20%, DBP not <100-110 mm Hg in first 24 hrGoal post tPA: BP <180/105 mm HgDrug of choice: Nicardipine, clevidipine, or labetalol
  • Hemorrhagic CVA or SAH:Treat if SBP >180 mm Hg/DBP >100 mm HgGoal: MAP lowered by 20-25% within the 1st hr or SBP 140-160 mm HgDrug of choice: Nicardipine, clevidipine, or labetalolAvoid dilating cerebral vessels with nitroglycerin or nitroprusside
  • ACS:Goal: MAP to 60-100 mm HgDrug of choice: Labetalol or esmolol in combination with nitroglycerinAvoid: Hydralazine (reflex tachycardia) and nitroprusside ("coronary steal"пїЅ)
  • AHF:Goal: MAP to 60-100 mm HgDrug of choice nitroprusside or NTG with ACEI and/or loop diuretic
  • Acute renal failure/microangiopathic anemia:Goal: MAP lowered by 20-25% within 1st hrDrug of choice: Nicardipine, clevidipine, or fenoldopam. For scleroderma renal crises ACEI are drugs of choice.
  • Aortic dissection:Reduce shear force (dP/dT) by reducing both BP and HRβ-blockade must precede any drug that may cause reflex tachycardiaGoal: SBP 100-120 mm Hg and HR <65 bpm within 1st 20 minDrug of choice: Esmolol in combination with dihydropyridine CCB or nitroprussideConsult vascular surgery if type A
  • Sympathomimetics (pheochromocytoma, cocaine, amphetamines):Goal: MAP lowered by 20-25% within 1st hrAvoid pure β-blockade (О± is left unopposed)Drug of choice: Phentolamine or calcium channel blocker with benzodiazepine. Use clonidine in cases of clonidine withdrawal
  • Preeclampsia:Definition: SBP >140 or DBP >90 mm Hg with proteinuria (>300 mg/24 hr or a urine protein/creatinine >0.3 or dipstick 1+)Occurs >20 wk gestation - 4 wk postpartumHeadache, vision changes, peripheral edema, RUQ painComplications: Eclampsia, HELLPGoal: SBP 130-150 mm Hg and DBP 80-100 mm HgDrug of choice: Labetalol, nicardipine, hydralazine, magnesiumConsult Obstetrics
  • Esmolol:β1-blockadeOnset 60s, duration 10-20 minAvoid in AHF, COPD, heart block
  • Labetalol:Combined О±- and β-blockerOnset 2-5 min, duration 2-6 hrNo reflex tachycardia due to β-blockadeAvoid in: COPD, AHF, bradycardia
  • Clevidipine:3rd generation dihydropyridine CCBOnset 2-4 min, duration 5-15 minElimination independent of liver/renal functionAvoid in allergies to soy or egg products, defective lipid metabolism, AFib
  • Nicardipine:2nd generation dihydropyridine CCBOnset 5-15 min, duration 4-6 hrAvoid in: AHF, coronary ischemia
  • Nitroglycerin:Venous > arteriolar dilationOnset 2-5 min, duration 10-20 minPerfuses coronaries, decreasing ischemiaCauses reflex tachycardia, tachyphylaxis, methemoglobinemia
  • Nitroprusside:Short-acting arterial and venous dilatorOnset 3 s, duration 1-2 minComplications:Reflex tachycardia, "coronary steal"пїЅ, increase ICPCyanide toxicity after prolonged useAvoid in pregnancy, renal failure (relative)
  • Hydralazine:Arteriolar dilatorOnset 5-15 min, duration 3-10 hrHypotensive effect may be less predictableSafe in pregnancy
  • Enalaprilat:ACE inhibitorOnset 0.5-4 hr, duration 6 hrAvoid in: Pregnancy, AMI
  • Fenoldopam:Selective postsynaptic dopaminergic receptor agonist (DA1)Onset 5-15 min, duration 1-4 hrNo reflex tachycardiaMaintains renal perfusionAvoid in: Glaucoma
  • Phentolamine:О±1-blocker, peripheral vasodilatorOnset 1-2 min, duration 10-30 min

Medication

  • Clevidipine: 1-16 mg/h IV infusion
  • Enalaprilat: 1.25-5 mg q6h IV bolus
  • Esmolol: 80 mg IV bolus, then 150 Ојg/kg/min infusion
  • Fenoldopam: 0.1-0.6 Ојg/kg/min IV infusion
  • Hydralazine: 10-20 mg IV bolus
  • Labetalol: 20-80 mg IV bolus q10min (total 300 mg); 0.5-2 mg/min IV infusion
  • Nicardipine: 2-15 mg/h IV infusion
  • Nitroglycerin: 5-100 Ојg/min IV infusion; USE NON-PVC tubing
  • Nitroprusside: 0.25-10 Ојg/kg/min IV infusion
  • Phentolamine: 5-15 mg q5-15min IV bolus

Follow-Up

Disposition

Admission Criteria

  • All patients with end-organ damage
  • ICU for cardiac and BP monitoring

Discharge Criteria

  • Absence of end-organ damage
  • Likely to be compliant with primary care
  • Known history of HTN
  • Reversible precipitating cause (e.g., medication noncompliance)
  • Able to resume previous medication regimen
  • Return with chest pain or headache

Followup Recommendations

Initiation of a suitable medication regimen under care of a primary care provider пїЅ

Pearls and Pitfalls

  • Avoid IV agents for hypertensive urgency
  • BP goal in hypertensive emergency is a reduction of the MAP by 20-25% within the 1st hr except in ischemic CVA and aortic dissection
  • Avoid excessive or precipitous decrease in BP because it may exacerbate end-organ damage
  • Avoid reflex tachycardia in aortic dissection
  • Avoid unopposed О± in catecholamine excess

Additional Reading

  • Johnson пїЅW, Nguyen пїЅML, Patel пїЅR. Hypertension crisis in the emergency department. Cardiol Clin. 2012; 30(4):533-543.
  • Marik пїЅPE, Rivera пїЅR. Hypertensive emergencies: An update. Curr Opin Crit Care. 2011;17:569-580.
  • Ram пїЅCV, Silverstein пїЅRL. Treatment of hypertensive urgencies and emergencies. Curr Hypertens Rep. 2009;11(5):307-314.
  • Rhoney пїЅD, Peacock пїЅWF. Intravenous therapy for hypertensive emergencies, part 1. Am J Health Syst Pharm. 2009;66(15):1343-1352.
  • Rhoney пїЅD, Peacock пїЅWF. Intravenous therapy for hypertensive emergencies, part 2. Am J Health Syst Pharm. 2009;66(16):1448-1457.

See Also (Topic, Algorithm, Electronic Media Element)

  • Acute Coronary Syndrome
  • Acute Stroke
  • Aortic Dissection
  • Congestive Heart Failure
  • Preeclampsia/Eclampsia
  • Subarachnoid Hemorrhage

Codes

ICD9

  • 401.9 Unspecified essential hypertension
  • 437.2 Hypertensive encephalopathy

ICD10

  • I10 Essential (primary) hypertension
  • I67.4 Hypertensive encephalopathy

SNOMED

  • 132721000119104 Hypertensive emergency (disorder)
  • 50490005 Hypertensive encephalopathy (disorder)
  • 443482000 hypertensive urgency (disorder)