emergency lectures - hypertensive emergencie
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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
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
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
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
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
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
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
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
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
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