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    Hypertensive Emergencies


    Last Updated Oct 20, 2020
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    By Paul Clerc


    • Hypertensive Emergency = a collection of syndromes whereby an acute elevation of BP causes acute target organ damage. Requires immediate treatment.
    • Hypertensive Emergencies represent approximately 0.1%-1% of patients. 1-3% with hypertension have a hypertensive emergency in their lifetime.
    • In-hospital death is 2.5% (~4.6% when admitted to CCU).
    • If untreated, median survival is 10.4 months and 1-year death rate >79%.
    • Hypertensive Urgencies or Severe Asymptomatic Hypertension = Systolic BP >180 or Diastolic BP >120 mmHg without target organ damage. Optimal timeframe for initiating treatment is < 1 week to up to 3 months.

    * This clinical summary will not address rare conditions such as pheochromocytoma.

    What represents acute target organ damage?

    • Acute heart failure/pulmonary edema (22-30%).
    • Acute coronary syndrome (18-25%).
    • Aortic dissection (3.5-8%).
    • Hypertensive encephalopathy (2.6-16%).
    • Acute ischemic stroke (24%).
    • Intracranial hemorrhage (4.5-15%).
    • Acute kidney injury (0.5%).
    • Hypertensive retinopathy.
    • Eclampsia/Pre-eclampsia (up to 6 weeks post-delivery).

    Note: Headache (non-pregnant) or epistaxis are not target organ damage

    Clinical Endpoint

    • Hypertensive Emergency patients should be admitted to ICU.
    • Immediate BP reduction and hospitalization not indicated for Hypertensive Urgency/Severe Asymptomatic Hypertension.

    Diagnostic Process

    Historical features

    • Missed anti-hypertensives.
    • Recently started or discontinued medications (eg. clonidine).
    • Recreational drugs (eg. cocaine, amphetamines, phencyclidine).
    • Disease processes (eg. hyperaldosteronism, thyroid storm, autonomic dysreflexia).
    • Physiological processes (eg. Pain).
    • # weeks gestation if pregnant, or delivery date.
    • Baseline BP if known and comorbid medical conditions.
    • Previous hypertensive emergencies/pre-existing target organ damage.

    Most patients: CBC, Electrolytes, BUN, Creatinine, Glucose, B-HCG.

    • Acute Coronary Syndrome
      • Chest pain/anginal equivalents, dyspnea, increased fatigue, vomiting.
      • Murmur or S3 – possible papillary dysfunction, diaphoretic.
      • ECG, troponin (+ repeat if indicated by site/guidelines).
    • Aortic Dissection
      • Chest pain/anginal equivalents, back/abdo pain, neurological deficits, syncope.
      • Unequal BP (>20 mmHg) in extremities, pulse differential, focal neurological deficits.
      • CXR, POCUS – for dissection flap,
      • CT Chest with contrast,
      • Troponin – coronary dissection.
    • Acute heart failure/pulmonary edema
      • Dyspnea, increased fatigue, orthopnea, cough.
      • Murmur or S3, edema, crackles on auscultation, elevated JVP, hypoxia.
      • CXR, ECG, POCUS – myocardial function, TSH, Liver enzymes.
      • Ischemic stroke, intracranial hemorrhage, hypertensive encephalopathy
        • Altered mental status, neurological deficits focal and non-focal, vomiting (raised ICP).
        • CN abnormalities, power/sensation/reflex/cerebellar deficits.
        • INR/PTT, CT Head with + without contrast.
    • Pregnancy
      • Pre-eclampsia:
        • Headache, visual disturbance, abdominal pain (RUQ).
        • RUQ pain, edema.
        • B-HCG, CBC, Creatinine, Liver enzymes for HELLP syndrome, urine dip – for protein.
      • Eclampsia:
        • Seizures.
    •  Acute kidney injury
      • Decreased urine output.
      • Edema.
      • Creatinine.
    •  Sympathomimetics
      • Various presentations, chest pain – cocaine vasospasm, acute heart failure.
      • Hyperthermic.
      • Urine toxicology – cocaine, amphetamines, phencyclidine.
    • Hypertensive retinopathy
      • Blurred vision or visual field defects.
      • Fundoscopy flame hemorrhages and exudates.

    Treatment Goals

    • Elevated BP without target organ damage (Hypertensive Urgency/Severe Asymptomatic Hypertension) requires no emergent treatment.
    • For Hypertensive Emergencies manage target organ damage/reduce complications.
    • No RCTs show improved morbidity/mortality benefits from treatment but expert consensus and guidelines suggest high likelihood of benefit.

    Treatment Principles

    • Monitored bed, regular BP monitoring.
    • 1st hour: reduce SBP (or MAP) 20-25% (ideally within minutes for eclampsia and aortic dissections).
    • 2-6 hrs: subsequent reduction to <160 mmHg Systolic and <100-110 mmHg Diastolic.
    • 24-48 hrs: Return to baseline BP if known, <140/90 if unknown (low evidence).

    Antihypertensive Medications:

    • No single antihypertensive agent is recommended.
    • Use intravenous medications.
    • Rapid-acting sublingual or oral medications (nitroglycerin spray, captopril) can be useful while setting up infusion/lack of IV access.

    Specific Considerations

    Acute LV Failure with Pulmonary Edema

    • Nitroglycerin OR Sodium Nitroprusside.
    • Furosemide.
    • Avoid hydralazine (increased cardiac work) and beta-blockers (decreased cardiac contractility).

    Acute Coronary Syndromes

    • Nitroglycerin OR Labetalol OR Esmolol.
    • Avoid hydralazine (increased cardiac work).

    Aortic Dissection

    • Rapid HR reduction in first 10 minutes to <60.
    • BP reduction to <120 mmHg in first 20 min, discussion with ICU on need for arterial line.
    • Labetalol OR Esmolol OR Metoprolol OR Nitroglycerin OR Sodium Nitroprusside.


    • Magnesium sulfate in eclampsia.
    • Nifedipine OR Labetalol OR Hydralazine OR Methyldopa in pre-eclampsia.

    Hypertensive Encephalopathy

    • Diagnosis of exclusion after ruling out intracranial pathology.
    • Labetalol OR Hydralazine.
    • Avoid sodium nitroprusside if suspected ICP due to intracerebral shunting.

    Acute Ischemic Stroke

    • Higher MAP essential to perfusion. BP should not be lowered acutely except at extremes (some clinicians use >220/120). Gradual BP reduction should occur.
    • Thrombolysis contraindicated with extreme hypertension due to risk of bleeding. Lower BP to <185/110 pre-treatment and maintain <185/105 throughout treatment.
    • Labetalol OR Hydralazine OR Enalapril often used.

    Acute Intracranial Hemorrhage

    • Systolic BP >220 mmHg can be harmful.
    • Debate exists over target BP, <140 mmHg or <180 mmHg systolic often used.
    • Labetalol OR Esmolol OR Enalapril OR Phentolamine.


    • While not target organ damage, it may mimic other presentations (ACS, encephalopathy) and additional medications can be considered.
    • IV Lorazepam for stimulants.
    • Phentolamine OR Nitroglycerin OR Sodium Nitroprusside.
    • Avoid beta-blockers (risk abrupt BP rise/coronary vasoconstriction due to catecholamines on unblocked alpha receptors).


    Criteria For Hospital Admission

    • Hypertensive Emergencies should be admitted to ICU for BP monitoring, intravenous antihypertensives, and target organ damage management.

    Criteria For Safe Discharge Home

    • A patient with a Hypertensive Emergency should not be discharged home.
    • If no target organ damage, the patient does not require immediate treatment and can be discharged home (ie. Hypertensive Urgency/Severe Asymptomatic Hypertension).
      • A patient with SBP >180 or DBP > 110 DBP can be diagnosed with hypertension according to Hypertension Canada guidelines.
      • No immediate lowering of BP is necessary and rapid lowering of BP (IV meds) may cause harm due to the shifted autoregulation of BP; however,
      • Canadian Emergency Medicine Cardiac Research and Education Group advises to consider oral antihypertensive therapy for these individuals >180 SBP or 110 DBP and to initiate treatment for SBP >230 or DBP >130.
      • Follow-up should be arranged within 7 days and electrolytes checked within 1 week for ACE/ARB initiation.

    Other Resources

    Quality Of Evidence?


    ICU admission: >1 high-quality, non-randomized trials or meta-analyses.


    BP targets and specific antihypertensives: expert opinion/consensus.


    Related Information

    Reference List

    Relevant Resources


    View all Resources


    Cardiovascular Emergencies

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