Hypertensive Emergency

1. Hypertensive Emergency Daniel J. McFarlane M.D. Division of Hospital Medicine January 2011

2. Outline • Epidemiology • Definitions • Pathophysiology • Diagnosis and Recognition • Treatment • Special Circumstances

3. 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

4. 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.

5. 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%

6. 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

7. 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

8. 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%

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

10. 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

11. 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

12. 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

13. 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

14. Treatment • Hypertensive Urgency • Appropriate follow up for asymptomatic patients with no end-organ damage BP 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

15. 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.

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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.