Hypertensive Crisis

    .

     

     

    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:
    1. Malignant HTN + papilledema
    2. Cerebrovascular
      • Hypertensive encepalopathy
      • CVA with severe hypertension
      • Intracerebral hemorrhage
      • SAH
    3. Cardiac
      • Aortic dissection
      • LV failure (new onset CHF)
      • MI
    4. 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.
      • 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!
    • 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

    Tag page (Edit tags)
    • No tags
    Page statistics
    3866 view(s), 6 edit(s) and 10489 character(s)

    Comments

    You must login to post a comment.

    Attach file

    Attachments