Hypertensive Emergency
Daniel J. McFarlane M.D.Division of Hospital MedicineJanuary 2011
Outline
Epidemiology Definitions Pathophysiology Diagnosis and Recognition Treatment Special Circumstances
Epidemiology
Why should we care about hypertension? One of the most common chronic medical
concerns in the US Affects >30% of the population > age 20 Risk factor for
Cardiovascular disease and mortality Cerebrovascular disease and mortality End stage renal disease Other end organ damage
Epidemiology
Why should we care about hypertension? 30% of the population is unaware they have
hypertension Control rates for known cases is about 50% (we
don’t do a great job at controlling BP) Risk Factors
If >50, systolic BP > 140 is a more concerning risk factor for cardiovascular disease than diastolic BP.
The risk of cardiovascular disease doubles for every increase in BP of 20/10 over 115/75.
Epidemiology
Hypertensive Emergency Estimates are that about 1% of those
with hypertension will present with hypertensive emergency each year
That is >500,000 Americans per year Correct and quick diagnosis and
management is critical Mortality rate of up to 90%
Definitions
Hypertension (according to JNC VII) Normal BP <120/<80 Prehypertension 121-139/80-89 Stage I HTN 140-
159/90-99 Stage II HTN >160/>100 (Severe HTN >180/>110)
Severe HTN is not a JNC VII defined entity
Definitions
Hypertensive Emergency Acute, rapidly evolving end-organ damage
associated with HTN (usu. DBP > 120) BP should be controlled within hours and
requires admission to a critical care setting Hypertensive Urgency
DBP > 120 that requires control in BP over 24 to 48 hours
No end organ damage Malignant Hypertension is no longer used
Definitions End-Organ Damage (% of cases)
Cerebral infarction…………………………………… 24% Hypertensive encephalopathy……………………16% Intracranial hemorrhage……………………………4.5% Acute aortic dissection………………………………2% Acute coronary syndrome/myocardial infarction…12% Pulmonary edema with respiratory failure…………22% Severe eclampsia/HELLP syndrome………………2% Acute congestive heart failure……………………14% Acute renal failure……………………………………9%
Pathophysiology
Hypertensive Emergency Failure of normal autoregulatory function Leads to a sharp increase in systemic
vascular resistance Endovascular injury with arteriole necrosis Ischemia, platelet deposition and release of
vasoactive substances Further loss of autoregulatory mechanism Exposes organs to increased pressure
Diagnosis and Recognition
Presentation Always present with a new onset
symptom Take a good history
History of HTN and previous control Medications with dosage and compliance Illicit drug use, OTC drugs
Diagnosis and Recognition
Physical Confirm BP in more than one extremity Ensure appropriate cuff size Pulses in all extremities Lung exam—look for pulmonary edema Cardiac—murmurs or gallops, angina, EKG Renal—renal artery bruit, hematuria Neurologic—focal deficits, HA, altered MS Fundoscopic exam—retinopathy, hemorrhage
Diagnosis and Recognition
Laboratory/Radiologic evaluations Basic Metabolic Panel (BUN, Cr) CBC with smear (hemolytic anemia) Urinalysis (proteinuria, hematuria) EKG to look for ischemia CXR to look for pulmonary edema if dyspnea Head CT for hemorrhage if HA or altered MS MRI chest if unequal pulses and wide
mediastinum to look for aortic dissection
Treatment
Hypertensive Urgency No end-organ damage—NOT emergent Look for reactive HTN and treat this first
Drugs, pain, anxiety, cocaine, withdrawal Use oral medications to lower BP gradually
over 24-48 hours, likely 2 agents needed May be chronic, decrease BP slowly to avoid
hypoperfusion of organs Avoid sublingual and IM administration due to
unpredictable absorption
Treatment
Hypertensive Urgency Appropriate follow up for asymptomatic
patients with no end-organ damageBP range Action Plan
140-159/90-99 Observe, confirm BP 2mos 160-179/100-109 Confirm, treat within 1mo 180-209/110-119 Confirm, treat within 1wk 210+/120+ Confirm, treat now, close
f/u
Medications
Oral drug choices often based on comorbid conditions Heart failure—TH, BB, ACEI, ARB, ALDO Post MI—BB, ACEI, ALDO High CVD risk—TH, BB, ACEI, CCB Diabetes—TH, BB, ACEI, ARB, CCB Chronic Renal Failure—ACEI, ARB Recurrent stroke prevention—TH, ACEI
KEY: ACEI, angiotensin converting enzyme inhibitor; ALDO, aldosterone antagonist; ARB, angiotensin receptor blocker; BB, b blocker; CCB, calcium channel blocker; TH, thiazide.
Treatment Hypertensive Emergency
Act Quickly Start IV goal directed pharmacologic therapy
Continuous infusion: short acting titratable meds Initiate critical care monitoring
Intraortic BP monitoring may be necessary Start SLOW: Limit initial lowering of BP to 20% below
pretreatment level Due to increased threshold of hypoperfusion of
the organs from abnormal autoregulation Goal: Lower DBP by 10-15% in 30-60 min Initiate oral therapy and titrate IV medications down
Medications
IV, short acting, titratable. Arterial Vasodilators
Hydralazine, fenoldepam, nicardipine, enalapril Venous Vasodilators
Nitroglycerine Mixed Arterial and Venous Vasodilators
Sodium nitroprusside Negative Inotrope/Chronotrope
Labetolol (also vasodilates), Esmolol Alpha blockers (inc. sympathetic activity)
Phentolamine
Medications
Preferred agents by usage Labetolol>Esmolol>Nicardipine>Fenoldopam (esp
in pheochromocytoma) Preferred agents by end organ damage
Pulmonary Edema (systolic)—Nicardipine Pulmonary Edema (diastolic)—Esmolol Acute MI—Labetolol or Esmolol Hypertensive Encephalopathy—Labetolol Acute Aortic Dissection—Labetolol Eclampsia—Labetolol or Nicardipine Acute Renal Failure—Fenoldopam Sympathetic Crisis/Cocaine—Verapamil or Diltiazem
Special Circumstances
Acute Aortic Dissection Start IV meds STAT to lower pulsitile load and
aortic stress to lessen the dissection Vasodilators alone may reflex tachycardia Use beta blocker AND vasodilator
Esmolol and Nitroprusside Surgical evaluation
Type A all go to surgery Type B only if rupture/leak. Treat with
aggressive BP control
Special Circumstances
Stroke Number one cause of permanent disability HTN is a protective physiologic effect to maintain
blood flow to brain One study showed better outcome if hypertensive
upon presentation of stroke Treat HTN “rarely and cautiously”
Lower BP 10-15% in first 24 hours (not >20%) Hemorrhagic stroke
Treat if >200/>110, but still with modest lowering of BP because still worse outcome with low BP
Special Circumstances
Eclampsia Vasoconstricted and hemoconcentrated Volume expand, magnesium sulfate, and
aggressive BP control. Delivery is only definitive treatment Labetolol or Nicardipine are drugs of choice. Hydralazine was first line but slow onset and
unpredictable so may lead to hypotension
Special Circumstances
Sympathetic Crisis Cocaine use, rarely pheochromocytoma AVOID beta blockers—leads to uninhibited
alpha stimulation and increased BP Labetolol has alpha and beta blockade, but
experimental studies show poor outcomes Nicardipine, fenoldopam or verapamil (with a
benzodiazepine) are drugs of choice
References
Haas, A. and Marik, P. “Current Diagnosis and Management of Hypertensive Emergency.” Seminars in Dialysis. Vol 19, No 6. (2006) pp. 502-512.
Flanigan, J. and Vitberg, D. “Hypertensive Emergency and Severe Hypertension: What to Treat, Who to Treat, and How to Treat.” The Medical Clinics of North America. Vol 90 (2006) pp. 439-451.
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