Hypertensive emergency

Diagnosis

Need for acute BP reduction d/t end-organ dysfunction

Generally need ≥180/120 mmHg, but usually >220/130

BRAIN- HTN encephelopathy, seizure, ICH, ischemic stroke

HEART- AMI, CHF/LV failure/pulm edema, Aortic Dissection

EYES- Retinal hemorrhages, exudates, or papilledema

KIDNEYS- Acute Renal Failure

(Pre)Eclampsia

Catecholamine-induced HTN

CAUTION: Ischemic stroke and tPA candidates

Treatment

GOAL: Reduction of MAP by 10-15% in first 1-2 hrs

(no more than 25%, except in dissection)

MAP= (2/3)DBP +(1/3)SBP

DRUGSNitroprusside

mech - arteriolar and venous dilation

pros - very effective rapid on/offset

cons - cyanide toxicity, caution in renal insufficiency

        - potential hypotension and end-organ hypoperfusion

        -  tissue necrosis if extravasation

        - increases intracranial pressure

dose - 0.5-8 mcg/kg/min

Nitroglycerin

mech - venodilation at low doses, arteiolar at high doses

pros - usually readily available in the ED

       - rapid on/offset

       - improves coronary collateral flow

       - good for CHF, angina; bad for HTN crisis

cons- tachycardia, tolerance

dose - 10-250 mcg/min

Labetalol

mech- alpha/beta blockers (beta>alpha), vasoldilation

pros- no change in HR

cons- not for copd, those with beta-blocker intolerance

dose - if bolused, 20mg, 40-80mg q10min (max 300mg)

2 mg/min infusion

Hydralazine

mech- arteriolar dilator

pros- obs like it for eclampsia

cons- reflex tachycardia, unpredictable bp effect, sometimes takes hours for effect

dose - 10mg q20min

0.5-1 mg/min IV infusion

Nicardapine

mech- CCB (dihydropyridine); decreased PVR > cardiac

pros- rapid onset, neurosrugeons like it

cons- slower offset than NTP or NTG

dose - 5 mg/hr, max 15mg/hr

ACE-i (enalaprilat)

no well studied

dose - 1.25 mg q6 hr

Fenlodopam

mech- peripheral dopamine agonist--->ateriolar dilation

pros- rapid on/offset, renal insufficiency

cons- $$$

dose - 0.1 µg/kg/min

Phentolamine

mech- alpha blocker

pros- esp, pheochromcytoma (catecholamine-induced)

cons- hard to find, waiting for pharmacy

dose - 5 to 10 mg every 5 to 15 minutes

0.2-5 mg/min IV infusion

Esmolol

mech- beta blocker

pros- ultra short-acting, dissection

cons- not for copd, those with beta-blocker intolerance

dose - Loading dose: 250-500 mcg/kg infused over 1 min

Maintenance infusion: 50 mcg/kg/min over 4 min

Organ Specific

HTN Encephalopathy

    Controlled redxn of BP over 1h; never < 110 diastolic

         Labetolol, nicardipine, fenoldopam; nitroprusside of diastolic > 140

Stroke

    10-15% reduction of MAP; diastolic not < 110

    lower to 185/110 in ischemic stroke to meet t-PA criteria

         Labetolol, nicardipine, nitroprusside as above

Acute Aortic Dissection

    Rapid redxn of BP, systolic bp 100-120; HR 60-80 within 20mins

    Prevent reflex tachycardia

         Nitroprusside, fenoldopam, nicardipine with metoprolol or esmolol; labetolol alone

ACS and Pulmonary Edema

    Nitroglycerin

Eslampsia/Pre-eclampsia

    Labetolol, nicardipine or IV hydralazine

    Magnesium

Cocaine and Amphetamine Toxicitiy

    BDZs

    Mixed alpha + B blockade: phentolamine or nitroprusside plus beta blocker

Pheochromocytoma

    Phentolamine or nitroprusside plus beta blocker

ARF

    Fenoldopam, nicardipine; nitroprusside risk cyanide toxicity (renal metabolism)

Source

Adapted from Bessen, Bresler (ACEP '09)