Hypertensive emergency

Diagnosis

• End-organ damage 2/2 increased BP (generally >180/120, usually > 220/130)
  • Brain - Encephelopathy, seizure, ICH, ischemic stroke
  • Eyes - Retinal hemorrhage, exudate, papilledema
  • CV - MI, CHF/LV failure/pulm edema, aortic dissection
  • Renal - Acute failure, hematuria, proteinuria
• Ancillary Tests
  • Chemistry - assess renal failure
  • UA - Assess renal failure, glomerulo nephritis, preeclampsia
  • Troponin
  • CXR - Evidenceo failure, dissection
  • ECG

Etiology

• Idiopathic
• Sympathomimetic drug use
• Preeclampsia
• Acute glomerulonephritis

Treatment

• Goal: Lower diastolic pressure to 105mmHg within 2-6 hours
  • Maximum initial fall in BP should not exceed 25% of presenting value
• Be careful of lowering BP in pts with CVA!

Drug	Dose	Mechanism	Pros	Cons	Notes
Nitroprusside	0.25-8 ?g/kg/min (start at 0.25)	Arterial and veno-dilator	1. Very effective 2. Immediate onset/offset	1. Cyanide Toxicity 2. Coronary steal? 3. Incr HR	1. Avoid in liver/renal failure 2. Avoid with incr ICP 3. Avoid in pregnancy
Nitgroglycerin	5-100 ?g/min	Veno>arteriodilation	1. Rapid on/offset 2. Increases coronary flow	Causes Tachycardia	Drug of choice in pts w/ cardiac ischemia, LV dysfunction, and pulm edema
Labetalol	20-80mg IV bolus q10min OR 0.5-2mg/min IV	Beta>alpha blocker	1. No change in HR, cerebral flow 2. Rapid onset	Avoid in COPD, CHF heart block	1. Consider in ACS 2. Consider in ischemic CVA
Esmolol	250-500 ?g/kg/min; may repeat bolus after 5min or incr to 300 ?g/min	Beta selective	1. Rapid on/offset	Avoid in COPD, CHF bradycardia	Consider in ACS
Nicardipine	5-15mg/h	Decreases PVR	Good for intracranial pathology	Slower onset/offset	Avoid in CHF, ACS
Hydralazine	5-10mg IV bolus, max dose 20mg OR 0.5-1mg/min IV infusion	Arteriolar vasodilator	Rarely causes hypotension	Avoid in CAD	Primarily used in pregancy
Phentolamine	5-10mg IV bolus q5-15min OR 0.2-5mg/min IV infusion	Alpha blocker			Used for catecholamine-induced HTN
Enalapril	1.25mg over 5min q6hr	Decreases HR, SV, systemic arterial pressure	Does not impair cerebral flow	Variable response	1. Used in pts at risk for cerebral hypotension, CHF 2. Avoid in pregnancy

Disease 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), UpToDate