emergency lectures - hypertensive emergencie

Hypertensive Emergencies

Sushama A. Saijwani, MD. Boston Medical Center. Department of Emergency Medicine

Outline of the talk….

Why should ER doctors care about Hypertension?

Blood Pressure Basics Stratification of Hypertensive Patients

Uncontrolled Severe HTNHypertensive UrgencyHypertensive Emergency**

Assessment of Hypertensive Patients Treatment Disposition

Why should we be concerned about Hypertension in the ER?

Global burden of hypertension: Analysis of worldwide data. Lancet.

2000: 26% world’s population had HTN2025: 1.5 billion people

2/3 Americans are unaware of their HTN

75% BP not well controlled

ER doctor: treat hypertensive emergencies & follow up

Blood Pressure BasicsNIH/Joint National Committee on Hypertension

Guidelines

Blood Pressure Basics

Primary or Essential HTN Unknown Cause 95%

Secondary HTNSpecific disease or medication5%

Stratification of Hypertensive Patients Uncontrolled Severe Hypertension

Chronic uncontrolled hypertension Long term management NOT acute treatment Follow up within 1 week

Hypertensive Urgency Increased blood pressure, high risk of developing end organ damage

WITHOUT new injury h/o end organ damage: CHF, UA, TIA, CVA, CRI, hypertensive

pregnancy Treatment 1-2 days PO meds

Hypertensive Emergency Rapid & Progressive high blood pressure causing end organ damage Immediate: 1-2 hours IV meds

Hypertensive EmergenciesCerebrovascular

Hypertensive Encephalopathy

Stroke: Ischemic & Hemorrhagic

Cardiovascular Crises ACS Aortic dissection CHF

Retinopathy Malignant

Accelerated HTN

Renal Crises Acute Kidney

Injury Glomerulonephritis

Other Pre/eclampsia Catecholamine

excess

Cerebrovascular Hypertensive Crises

Cerebral AutoregulationConstant blood flow despite ∆ BP

CPP = MAP - ICP Cerebral Perfusion Pressure = Mean Arterial

Pressure –Intracranial Pressure

Vasospasm, ischemia & edema in parieto occipital areas

Fails 25% above/below MAP or change in ICP

Cerebral Autoregulation

In chronically hypertensive patients:

Need higher BP before autoregulation disrupted BUT

More susceptible to ischemia when flow reduced

Lower limit is also higher SO

DO NOT drop MAP by more than 25%

Hypertensive Encephalopathy Cerebral over-perfusion

edema

Clinical Diagnosis

Symptoms: HTN, Change in MS,

Papilledema, HA, vision changes, seizures, vomiting

Mental Status improves with BP lowering

Cerebrovascular HTN Crises Ischemic CVA: thrombotic, embolic, hypoperfusion

Hemorrhagic Stroke: ICH or SAH

Survival of penumbra depends on cerebral perfusion

If we decrease BP too much less cerebral blood flow BUT

Continued infarction edema and increased ICP

How do we manage HTN so as not to risk extension of the stroke?

Only when MAP > 130 SBP >220






Accelerated HTN




excess

Malignant Accelerated Hypertension

AA men, renal dx, chronic HTN

Endothelial damage & vasculitis

Elevated BP & Retinopathy Papilledema Flame shaped hemorrhages Soft exudates HA, vision changes Proteinuria, Hematuria, worsening renal

function






Accelerated HTN




excess

Acute Coronary Syndrome

Increased myocardial demand Increased mass--LVH Increased afterload—LV wall tension Coronary arteries narrow

Reduce BP to normal!

Rx: Nitroglycerin: Reduces preload, after load, coronary

dilation β Blockers: Reduces HR

Aortic Dissection

Intimal tear & extension Mortality 1-2% per hour!! Substernal pain to the back Increased pulse pressure Ischemia to heart, kidney, gut

Type A BP meds & SurgeryType B Medical Mgt

Rx: DBP < 110 and lower HR

Esmolol & Nitroprusside or Labetalol

HTN in Congestive Heart Failure

LV overcome by increasing afterload

LVH & diastolic dysfunction

Pulmonary edema

Renin activation

HTN in Congestive Heart Failure

Acutely symptomatic nitroprusside infusion nitro paste slNG

ACEI: captopril

Diuretics may not be needed acutely

Beta blockers good in CHRONIC CHF but can WORSEN pulmonary edema






Accelerated HTN




excess

Renovascular Hypertensive Crisis

Both a cause & target organ

Parenchymal: Renal Artery stenosis Glomerulonephritis IgA nephropathy

Vascular: Damage impairs autoregulation with changes in BP

Rx: Nitroprusside or labetalol

http://wikis.lib.ncsu.edu/index.php/Image:Blood_pressure_control_kidney_hormones.gif






Accelerated HTN




excess

Pre-eclampsia & Eclampsia Pregnancy: 20 weeks - 2 weeks post

partum >140/90 or >30/15mm Hg over baseline BP Edema Proteinuria

HA, vision changes, low UO HELLP syndrome: Hemolysis, Elevated

LFTs, Low Platelets

Rx: Hydralazine boluses, B Blockers Eclampsia: Magnesium infusion, delivery

Catecholamine Excess

Drugs that elevate BP Sympathomimetics

Phenylephrine Cocaine Methamphetamine Careful with B Blockers!

MAOIs + Tyramine

Withdrawal: etoh, clonidine

Pheochromocytoma Increases norepinephrine Paroxysmal Hypertension Rx: Phentolamine, Labetalol

Oral contraceptives Steroids NSAIDs Nasal

decongestants TCAs MAOIs

Assessment of the Hypertensive Patient

• Arm at the level of the heart• BP in BOTH arms• Manual BP check• Treat pain, hypoxia, urinary retention, toxins

Accurate BP

• PE: papilledema, hemorrhages, exudates• CV: Increased JVP, rales, • Neuro: mental status, focal deficits

Look for target organ damage

• Renal function, electrolytes, plasma renin, tox screen

• ECG, Urinalysis• CXR, CT scan

Testing

Treatment: IV Meds

Drug Onset Duration Side Effects Indications

Vasodilators

Sodium Nitroprusside

Immediate 1-2 min CN toxicity, tachycardia

Widely used esp in neurologic

Nicardipine 5-10 min 1-4 h HA, tachycardia

Not CHF

Nitroglycerin 2-5 min 3-5 min HA Coronary ischemic

Hydralazine 20 min 3-8 h Tachy, HA eclampsia

Adrenergic Inhibitors

Labetalol 5-10min 3-6h AV block, ortho hypotension

Widely used Not CHF

Esmolol 1-2min 10-20min Hypotension Aortic Dissection

Phentolamine

1-2min 3-5min Tachy, HA Catecholamine excess

Oral BP meds

Treatment: Contraindications!

Drug Contraindication

ACEI/ARB PregnancyB/l renal artery stenosisHyperkalemiaAcute Kidney Injury

β Blockers High degree Heart BlockBradycardiaObstructive airway diseaseCHFCocaine

Diuretics GoutAKI

Calcium Channel Blocker

CHFPregnancy

Disposition? Treat pain, anxiety,

urinary retention, hypoxia, toxins

Taken BP meds?

Hypertensive Emergency Admit for treatment &

monitoring

Hypertensive Urgency Known h/o HTN Expected Compliance Reversible precipitating

cause Can resume previously

effective regimen Follow up in 1 week

Uncontrolled HTN Follow up

References Adams, J et al Emergency Medicine: Expert Consult p. 703-712 Aggarwal, M, Khan I. Hypertensive Crisis: Hypertensive

Emergencies and Urgencies. Cardiology Clinics 2006; 24: 135-146

Kearney PM, Whelton M, Reynolds K, et al. Global burden of hypertension: analysis of worldwide data. Lancet. 2005;365:217-223

Phillips R, Greenblatt J, Krakoff L. Hypertensive Emergencies: Diagnosis and Management. Progress in Cardiovascular Diseases 2002;45,1: 33-48

Shayne P, Pitts S. Severely Increased Blood Pressure in the Emergency Department. Ann Emerg Med. 2003;41:513-529

Tintinalli J et al. Emergency Medicine. A comprehensive study guide 6th ed 2006 The McGraw-Hill Companies, Inc.

Vaughan C, Delanty N. Hypertensive emergencies. Lancet 2000; 356: 411-417

emergency lectures - hypertensive emergencie

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