Hypertensive Emergencies

Hypertensive CrisisMegat Mohd Azman Bin AdzmiAimsEpidemiology/pathophysiologyDefinitions/common typesClinical evaluationGoals of treatmentPharmacotherapySpecific treatment

EpidemiologyHypertension(HPT) very common in Western countries. Currently, 6,267,376 million individuals 18 years with hypertension in MalaysiaProjected prevalence of hypertension in 2020 - 35.8%, with an estimated 7.6 million Malaysians age 18 years and above40% known with HTN - not on treatment60% on treatment BP not controlled to 110Stage II HPT further divided into:Hypertensive urgencyHypertensive emergency

JOINT NATIONAL COMMITTEE ON PREVENTION, DETECTION, EVALUATION AND TREATMENT OF HIGH BLOOD PRESSURE 1997/ 2003

Other TerminologySeverely elevated BP (JNC VII)Defined as BP > 180/120Accelerated HPT term used to describe individuals with chronic hypertension with associated group 3 Keith-Wagener-Baker retinopathyMalignant HPT describe those individuals with group 4 KWB retinopathy changes + papilledema

DefinitionsA Hypertensive Emergency exists when acute elevation of blood pressure is associated with acute and ongoing organ damage to the kidneys, brain, heart, eyes or vascular system

Does not specifically include BP levels, butSystolic >240mmHgDiastolic > 120 - 140mmHg

REQUIRES IMMEDIATE BLOOD PRESSURE REDUCTIONDefinitionsA Hypertensive Urgency exists when there is acute or chronic blood pressure elevation not associated with any observable acute organ damage

This can be hard to distinguish on clinical evaluation alone.

BP control over hours to daysConditions constituting evidence of EODHypertensive encephalopathyIntracerebral heamorrhageStrokeHead traumaIschemic heart disease (most common)AMIAcute LVF with P/oedemaUnstable anginaAortic dissectionEclampsiaLife threatening arterial bleedEtiologyMost common rapid unexplained rise in BP in pt with chronic essential HPTmost have history of poor treatment/compliance or an abrupt discont of their meds

Other causesRenal parenchymal disease (80% of sec.causes)Systemic disorders with renal involvement (SLE)Renovascular disease (Atheroscleroses/fibromuscular dysplasia)Endocrine ( phaeochromocytoma/cushing syndrome)Drugs (cocaine/amphetam/clonidine withdrawal/diet pills)CNS (trauma or spinal cord disorders Guillain-BarreCoarctation of the aortaPreeclampsia/EclampsiaPostop. HPTDiagnosis (History)Focus on presence of Sx of end-organ dysfunction(eod) Any identifiable etiology

Hypertension Hx last known normal BP prior diagnoses + Rx dietary and social factorsMedication Steroid use Estrogens Sympathomimetics MAO inhibitorSocial history smoking, alcohol illicit drugs (cocaine, stimulants)Family historyearly HPT in family memberscardiovascular and cerebrovascular diseaseDiabetesPheochromocytomaPregnant?

Diagnosis(History)Symptom spesific Hx suggesting EODCVS Hxprevious MI/angina/arrhythmias chest pain/SOB/Sx of CF/claudication/flank or back painNeurologic Hxprior strokes, neuro dysfunctionvisual changes, blurriness, loss of visual fields, severe headaches, nausea and vomiting, change in mental statusRenal HxUnderlying renal disease (RF)Acute onset changes in renal frequency (anuria/oliguria)Endocrine Hxdiabetes, thyroid dysfunction, Cushings syndrome

Diagnosis (Examination)Confirm elevated BPProper position, appropriate cuff sizeSupine and standing and both armsAsses EOD presentFundoscopy Retinopathy NeckEnlarged thryoid, carotid bruit, jugular venous distention

CVSEnlarged heart, S3, asymmetric pulses, arrhythmiasPulmonarySigns of LV dysfunction ( crackles, rhonchi)RenalRenal bruit, abdominal massesNeurologicLevel of consciousness, evidence of stroke, any focal sigs

Retinopathy

HTN Retinopathy (Keith-Wagner)Grade IMild arteriolar narrowing and sclerosisGrade IIDefinite focal narrowing and AV nickingModerate to marked sclerosis of the arteriolesGrade IIIRetinal haemorrhages, exudates and cotton wool spotsGrade IVSevere grade III and papilledemaInvestigationsLab studiesElectrolytes, urea and creatinineFBC and smearUrinalysis dipstix + microscopyOptional - tox screen - BHCG - Endocrine testing

Imaging studiesCXR (chest pain or SOB)Head CT/MRI brain (abn neurology)Chest CT/TEE/Aortic angio (Aortic dissection)

Other Tests- ECG

Treatment Hypertensive Urgency:Goal: Reduce BP to 20/10 above goal will require two agents to control their BP19-Rapid vs slow reduction depends on patients risk factors (elderly, h/o stroke, h/o CAD etc)in such patients BP should be reduced slowly to avoid ischemia-These patients should be started on po antihypertensive agents for better BP control once they leave the hospital; close follow-up with a PCP is necessary.Treatment Hypertensive Emergency:Goal: Lower Diastolic BP to approximately 100-105 over 2-6 hours; max initial fall not to exceed 25%More aggressive decrease can lead to ischemic stroke and myocardial ischemiaIf focal neurological sx presentobtain MRI to r/o acute stroke (rapid BP correction contraindicated)Parenteral antihypertensives (IV Drip) recommended over oral agents in hypertensive emergency

TreatmentRecommended parenteral antihypertensive agents (IV drip) for Hypertensive Emergencies and admission to ICUNitroprusside (cautious about cyanide toxicity), Nicardipine, and Labetalol.Once BP controlled, switch to oral anti-hypertensives and follow-up closely

21Nitroprusside, Nicardipine, and labetalol are commonly used medications in an ICU setting. Nicardipine and Labetalol are contraindicated in acute heart failure. Nitroprusside can cause cyanide toxicity.

TreatmentMedication options

Oral antihypertensivesChronic hypertensiveHypertensive urgency

IV antihypertensivesHypertensive emergencyPharmacology IV anti-HPTVasodilatorsSodium nitroprussideNitroglycerinNicardipineFenoldapamHydralazineEnalapril

Adrenergic inhibitorsLabetalolEsmololPhentolamineIDEAL IV ANTI-HYPERTENSIVELower the BP without compromising blood flow to critical organs

Vasodilators generally considered 1st , because they preserve organ blood flow in the face of reduced perfusion and also tend to increase CO.

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Treatment for hypertension according to diagnosis

SummaryHypertensive Crises are commonDifferentiate Hypertensive Urgency from Emergency on the basis of end-organ damageCan treat hypertensive urgency with oral antihypertensives, but parenteral medications required for hypertensive emergencies25% reduction in diastolic BP over 2-6 hours for hypertensive emergenciesDont forget to start Oral antihypertensives and follow-up closely

References1.Hoshide, S., et al., Hemodynamic cerebral infarction triggered by excessive blood pressure reduction in hypertensive emergencies. Journal of the American Geriatrics Society, 1998. 46(9): p. 1179-80.2.Kitiyakara, C. and N.J. Guzman, Malignant hypertension and hypertensive emergencies. Journal of the American Society of Nephrology, 1998. 9(1): p. 133-42.3.Epstein, M., Diagnosis and management of hypertensive emergencies. Clinical Cornerstone, 1999. 2(1): p. 41-54.4.Kriegisteiner, S., et al., Hypertensive emergencies. Lancet, 2000. 356(9239): p. 1443.5.Mansoor, G.A. and W.H. Frishman, Comprehensive management of hypertensive emergencies and urgencies. Heart Disease, 2002. 4(6): p. 358-71.6.Vaughan, C.J. and N. Delanty, Hypertensive emergencies. Lancet, 2000. 356(9227): p. 411-7.