Can hypertension Can hypertension be an emergency be an emergency

bybyHossam Ahmed Hossam Ahmed

MowafiMowafi

Hypertensive CrisisHypertensive Crisis

Systemic hypertensionSystemic hypertension

It is estimated that 50 million persons in the United States have systemic

hypertension ,

many of whom are inadequately treated.

Between 1% and 2% of the 50 million have primary hypertension thatprogresses to a crisis phase

accounting for more than 50% of all cases of hypertensive crisis.

Uncontrolled or suboptimally controlled Uncontrolled or suboptimally controlled hypertensionhypertension

causes high rates causes high rates of mortality from of mortality from premature premature cardiac, vascularcardiac, vascular,,

and and renalrenal disease disease . .

In most instances, end-organ damage In most instances, end-organ damage

occurs afteroccurs after

decadesdecades

of elevated blood pressureof elevated blood pressure..

Hypertensive crisisHypertensive crisis

In rare instances, hypertension may become acutely life threatening. This emergency

situation, occurs when an abrupt, marked increase in blood pressure “relative to the patient's baseline” causes acute or rapidly progressing end-organ damage.

Unless promptly recognized and treated, hypertensive crisis can lead to

cardiovascular, renal, and

central nervous system complications and

death. Effective and prompt anti-hypertensive

treatment improves the prognosis.

Hypertensive crisis can manifest Hypertensive crisis can manifest

de novo, de novo,

but most patients have a history of but most patients have a history of chronically elevated blood pressure chronically elevated blood pressure

that has been that has been poorly controlled or untreated.

Public health campaignsPublic health campaigns

aimed at educating and treating aimed at educating and treating patients with hypertension havepatients with hypertension have

markedly decreasedmarkedly decreased

the incidence of hypertensive crisisthe incidence of hypertensive crisis . .

Nevertheless, it continues to represent Nevertheless, it continues to represent a large portion ofa large portion of

emergency department visitsemergency department visits..

Because the cardiovascular system is imminently threatenedBecause the cardiovascular system is imminently threatened , ,

cardiologistscardiologists

are called on to provide expert management of these emergencies, and patients with severe elevations in blood pressure are called on to provide expert management of these emergencies, and patients with severe elevations in blood pressure often go to a cardiologist for initial careoften go to a cardiologist for initial care . .

The cardiologist must be able to The cardiologist must be able to differentiate an differentiate an

emergencyemergency from from urgencyurgency or a or a pseudoemergency; pseudoemergency;

understand the underlying understand the underlying pathophysio-logic mechanisms, pathophysio-logic mechanisms,

potential complications, and potential complications, and treatment options; treatment options;

and and

guide the evaluation.guide the evaluation.

Overzealous treatment can cause severe morbidity and even death. A working knowledge of theOverzealous treatment can cause severe morbidity and even death. A working knowledge of the

pharmacologic characteristicspharmacologic characteristics

andand

side effects of the various therapeutic agents is essentialside effects of the various therapeutic agents is essential..

ClassificationClassification

Hypertensive crisis traditionally has been classified asHypertensive crisis traditionally has been classified as

emergencyemergency or or urgencyurgency,,

depending on the presence ofdepending on the presence of

acuteacute or or progressiveprogressive

end-organ damageend-organ damage . .

This distinctionThis distinction , ,

although not absolutealthough not absolute , ,

aids in formulating an effective aids in formulating an effective and safe treatment planand safe treatment plan..

Hypertensive emergencies include Hypertensive emergencies include conditions characterized byconditions characterized by

rapid decompensation of vital rapid decompensation of vital organ organ function caused by function caused by

inappropriate elevations in blood inappropriate elevations in blood pressurepressure . .

Treatment requiresTreatment requires

immediate reductionimmediate reduction

in blood pressure and parenteral medication, usually in an intensive care unitin blood pressure and parenteral medication, usually in an intensive care unit..

Delay may causeDelay may cause

irreversible organ damage and deathirreversible organ damage and death..

Several clinical syndromes can Several clinical syndromes can manifest as hypertensive manifest as hypertensive

emergenciesemergencies..

Accelerated or Accelerated or

malignant hypertension malignant hypertension

and and

hypertensive encephalopathy hypertensive encephalopathy

are the prototypical hypertensive emergencies. are the prototypical hypertensive emergencies.

Accelerated or malignant hypertension is a systemic disease characterized by:.Accelerated or malignant hypertension is a systemic disease characterized by:.• An extreme elevation in blood pressure (mean arterial blood pressure [MAP] greater than 120 mm Hg).An extreme elevation in blood pressure (mean arterial blood pressure [MAP] greater than 120 mm Hg).• Bilateral retinal hemorrhage. Bilateral retinal hemorrhage. • Exudates.Exudates.• Papilledema. Papilledema.

This hypertensive emergency demands emergency treatment and close follow-up care.This hypertensive emergency demands emergency treatment and close follow-up care.

HYPERTENSIVE EMERGENCIES 16HYPERTENSIVE EMERGENCIES 16

– In general, diastolic blood pressure exceeds 120 In general, diastolic blood pressure exceeds 120 mm Hg.mm Hg.

– Malignant hypertension with papilledema.Malignant hypertension with papilledema.– Hypertensive encephalopathy.Hypertensive encephalopathy.– Severe hypertension in the setting of Severe hypertension in the setting of

stroke.stroke.– Subarachnoid hemorrhage.Subarachnoid hemorrhage.– Head traumaHead trauma

– Acute aortic dissection.Acute aortic dissection.– Hypertension and left ventricular failure.Hypertension and left ventricular failure.– Hypertension and myocardial ischemia and Hypertension and myocardial ischemia and

infarction.infarction.– Hypertension after coronary artery bypass Hypertension after coronary artery bypass

operation.operation.– Pheochromocytoma crisis.Pheochromocytoma crisis.– Food or drug interactions with monoamine Food or drug interactions with monoamine

oxidase inhibitors.oxidase inhibitors.

– Cocaine abuse. Cocaine abuse. – Rebound hypertension after sudden drug Rebound hypertension after sudden drug

withdrawal (clonidine).withdrawal (clonidine).– Idiosyncratic drug reactions (atropine).Idiosyncratic drug reactions (atropine).– Eclampsia.Eclampsia.

Exceptions include Exceptions include cardiovascular cardiovascular dysfunction in which low blood pressure dysfunction in which low blood pressure

may represent an emergency.may represent an emergency.

"Considered emergencies when associated "Considered emergencies when associated with end-organ damage; with end-organ damage;

otherwise treated as urgencies.otherwise treated as urgencies.

Hypertensive encephalopathy causesHypertensive encephalopathy causes

headache, irritabilityheadache, irritability , ,

andand

altered state of consciousnessaltered state of consciousness

from a sudden marked increase in blood pressurefrom a sudden marked increase in blood pressure . .

Hypertensive encephalopathy occurs when cerebral edema is induced byHypertensive encephalopathy occurs when cerebral edema is induced by

markedly elevated blood pressuresmarkedly elevated blood pressures

that overwhelm thethat overwhelm the

auto-regulatory capabilitiesauto-regulatory capabilities

of the brainof the brain . .

This condition tends to affect a person This condition tends to affect a person with previously normal blood with previously normal blood

pressure who has a rapid rise in pressure who has a rapid rise in blood pressureblood pressure . .

Persons withPersons with

chronic hypertensionchronic hypertension

are relativelyare relatively

resistantresistant

to encephalopathy because their autoregulatory systems haveto encephalopathy because their autoregulatory systems have

adapted toadapted to

the chronically elevated blood pressurethe chronically elevated blood pressure..

When persons withWhen persons with

chronic hypertensionchronic hypertension do have do have encephalopathy, it is usually in the encephalopathy, it is usually in the setting of markedly elevated blood setting of markedly elevated blood

pressure pressure diastolic blood pressures diastolic blood pressures higher than 150 mm Hghigher than 150 mm Hg . .

Mental status reverts to normal with Mental status reverts to normal with the lowering of blood pressurethe lowering of blood pressure . .

Hypertensive urgenciesHypertensive urgencies

manifest as marked elevations in blood pressuremanifest as marked elevations in blood pressure

diastolic blood pressure higher thandiastolic blood pressure higher than

120mm Hg120mm Hg

withoutwithout

evidence of acute or progressive target organ damage and minimal or no symptomsevidence of acute or progressive target organ damage and minimal or no symptoms . .

The risk for tissue damage is not The risk for tissue damage is not immediateimmediate . .

Blood pressure can be loweredBlood pressure can be lowered

over a period of hours to daysover a period of hours to days . .

Patients usually can be treated with Patients usually can be treated with oral medication, often as outpatientsoral medication, often as outpatients..

PseudoemergenciesPseudoemergencies

must be differentiated from true hypertensive emergencies because the treatmentsmust be differentiated from true hypertensive emergencies because the treatments

differ markedlydiffer markedly . .

The increase in blood pressure in a pseudoemergency is caused byThe increase in blood pressure in a pseudoemergency is caused by

massive sympathetic outflowmassive sympathetic outflow

as the result ofas the result of

pain, hypoxia, hypercarbia, hypoglycemia, anxiety, pain, hypoxia, hypercarbia, hypoglycemia, anxiety, or the or the postictal statepostictal state . .

Treatment is directed at the underlying causeTreatment is directed at the underlying cause..

HYPERTENSIVE URGENCIESHYPERTENSIVE URGENCIES

Diastolic blood pressure exceeds 120 mm Diastolic blood pressure exceeds 120 mm Hg, but patients have no symptoms, and Hg, but patients have no symptoms, and

there are no signs of tissue damagethere are no signs of tissue damage

Clinical presentation. Clinical presentation. If an emergency is suspected,

appropriate arrangements for ICU admission

and parenteral treatment are made without waiting

for the results of further tests.

– Chest pain.Chest pain.– shortness of breath.shortness of breath.– Headache.Headache.– Blurred vision.Blurred vision.– signs of altered mental status.signs of altered mental status.– Focal neurologic signs.Focal neurologic signs.– Grade III or IV retinopathy.Grade III or IV retinopathy.– Rales. Rales. – Gallop.Gallop.– Pulse deficits.Pulse deficits.

– Chest pain.Chest pain.– shortness of breath.shortness of breath.– Headache.Headache.– Blurred vision.Blurred vision.– signs of altered mental status.signs of altered mental status.– Focal neurologic signs.Focal neurologic signs.– Grade III or IV retinopathy.Grade III or IV retinopathy.– Rales, Rales, – Gallop.Gallop.– Pulse deficits.Pulse deficits.

all point toward an emergency. all point toward an emergency.

Severe hypertension in the presence of Severe hypertension in the presence of chronic organ damagechronic organ damage

without associated symptoms does not constitute an emergencywithout associated symptoms does not constitute an emergency . .

Pseudoemergencies must be ruled outPseudoemergencies must be ruled out..

Signs and symptoms. Signs and symptoms.

The following history is elicited from patients withincreased The following history is elicited from patients withincreased

blood pressure.blood pressure.

– Nausea.Nausea.– Vomiting, weight loss.Vomiting, weight loss.– Anorexia. Anorexia. – Shortness of breath, chest pain.Shortness of breath, chest pain.– Headache.Headache.– Blurred vision.Blurred vision.– Abdominal pain. Abdominal pain. – Patients with accelerated or malignant Patients with accelerated or malignant

hypertension often have hypertension often have oliguria.oliguria.

Chronology of symptomsChronology of symptoms

is importantis important . .

History of hypertensionHistory of hypertension . .

Most patients with accelerated or malignant hypertension have an underlying history of chronic essential hypertensionMost patients with accelerated or malignant hypertension have an underlying history of chronic essential hypertension,,

althoughalthough

a significant percentage of patients have secondary forms of hypertensiona significant percentage of patients have secondary forms of hypertension . .

A search for correctable causes is A search for correctable causes is indicatedindicated..

Concurrent medications may includeConcurrent medications may include::

– Cardiac medications.Cardiac medications.– Antihypertensive agents.Antihypertensive agents.– Oral contraceptives.Oral contraceptives.– Diuretics.Diuretics.– Psychotropic agents.Psychotropic agents.– Monoamine oxi-Monoamine oxi-dase inhibitors.dase inhibitors.– Ephedrine.Ephedrine.– Over-the-counter cold remedies.Over-the-counter cold remedies.

Use of recreational drugs, Use of recreational drugs,

cocaine, amphetamines.cocaine, amphetamines.

Smoking history. Smokers are at Smoking history. Smokers are at increased risk for progression to increased risk for progression to

malignant hypertension. malignant hypertension.

Physical findingsPhysical findings

Vital signsVital signs . .

Blood pressure is measured in both Blood pressure is measured in both upper and lower extremitiesupper and lower extremities . .

Severe hypertension is confirmed with Severe hypertension is confirmed with two blood pressure measurements two blood pressure measurements

separated by 15 to 30 minutesseparated by 15 to 30 minutes . .

No absolute level of blood pressure No absolute level of blood pressure differentiates an emergencydifferentiates an emergency

from anfrom an

urgencyurgency..

The distinction is based on a thorough The distinction is based on a thorough clinical evaluationclinical evaluation . .

Optic fundi are examined for signs of Optic fundi are examined for signs of retinopathy,retinopathy, including including exudates, hemorrhages,exudates, hemorrhages, or or papilledema.papilledema.

The CNS is examined for The CNS is examined for

– Mental status.Mental status.– Focal neurologic signs. Focal neurologic signs. – Patients with hypertensive encephalopathy may manifest focal neurologic signs, confusion, or seizure activity.Patients with hypertensive encephalopathy may manifest focal neurologic signs, confusion, or seizure activity.

HeartHeart

and lungs are examined for presence of edema, S3, or S4.and lungs are examined for presence of edema, S3, or S4.

Vascular system Vascular system

is examined for pulses and bruits.is examined for pulses and bruits.

Patients with chronic hypertensionPatients with chronic hypertension

usually progressusually progress

to an accelerated or malignant phase or have severe blood pressure elevations and progressive end-organ damage and aortic dissectionto an accelerated or malignant phase or have severe blood pressure elevations and progressive end-organ damage and aortic dissection . .

A thorough searchA thorough search

for secondary causes and precipitants for secondary causes and precipitants is indicated in the evaluation of all is indicated in the evaluation of all

patients with hypertensive crisispatients with hypertensive crisis . .

Between 20% and 56% of patients have anBetween 20% and 56% of patients have an

identifiable underlyingidentifiable underlying

cause, compared with less than 5% of those cause, compared with less than 5% of those with uncomplicated hypertensionwith uncomplicated hypertension..

CONDITIONS THAT MAY PRECIPITATE A HYPERTENSIVE CRISISCONDITIONS THAT MAY PRECIPITATE A HYPERTENSIVE CRISIS– Essential hypertension. Essential hypertension. – Renovascular hypertension.Renovascular hypertension.– Parenchymal renal diseases.Parenchymal renal diseases.– Drug-induced causes.Drug-induced causes.– Head injuries.Head injuries.– Central nervous system events.Central nervous system events.– Vasculitis Collagen vascular disease.Vasculitis Collagen vascular disease.

HYPERTENSIVE CRISIS HYPERTENSIVE CRISIS

A common situation is that a A common situation is that a patient patient has been.has been.– Inadequately treated.Inadequately treated.– Has been noncompliant with a medical Has been noncompliant with a medical

regimen.regimen.

Risk factors for progression to Risk factors for progression to hypertensive crisis include.hypertensive crisis include.

– Male sex.Male sex.– Black race.Black race.– Cigarette smoking.Cigarette smoking.– Tobacco abuse.Tobacco abuse.– Oral contraceptive use.Oral contraceptive use.– Low socioeco-nomic status. Low socioeco-nomic status.

Unlike essential hypertension, the Unlike essential hypertension, the incidence of which increases with incidence of which increases with

age, the age, the

peak incidencepeak incidence

of hypertensive crisis occurs among of hypertensive crisis occurs among persons 40 to 50 years old.persons 40 to 50 years old.

Underlying diseases that can precipitate hypertensive crisis includeUnderlying diseases that can precipitate hypertensive crisis include – Renal parenchymal disease.– Renovascular hypertension.– Collagen vascular disease.– Pheochromocytoma.– Vasculitis.– Preeclampsia.– Burns– Head trauma.

A number of medications can cause marked elevations in systemic blood pressure. A number of medications can cause marked elevations in systemic blood pressure.

The most common offenders areThe most common offenders are– Oral contraceptives.Oral contraceptives.– Sympathomimetic agents.Sympathomimetic agents.– Cold remedies.Cold remedies.– Nonsteroidal antiinflammatory drugs.Nonsteroidal antiinflammatory drugs.– Cocaine.Cocaine.– Tricyclic antidepressants.Tricyclic antidepressants.– Mono-amine oxidase inhibitors.Mono-amine oxidase inhibitors.

In rare instances, a hypertensive crisis is the In rare instances, a hypertensive crisis is the first manifestation of disease.first manifestation of disease. These patients tend to have secondary forms of hypertension, most These patients tend to have secondary forms of hypertension, most commonly: commonly: – Renovascular.Renovascular.– Renal parenchymal disease.Renal parenchymal disease.– Reaction to medications.Reaction to medications.

Left ventricular failure or Left ventricular failure or pulmonary edemapulmonary edema . .

Elevated blood pressure poses an enormous workload on a failing

heart. Even patients with normal systolic function can have pulmonary

edema in the setting of markedly elevated blood pressures afterload

mismatch.

Hypertensive crisis associated with Hypertensive crisis associated with hypercatecholaminemiahypercatecholaminemia . .

A hypercatecholamine state can causeA hypercatecholamine state can cause severesevere

elevations in blood pressure that threaten tissue function and necessitateelevations in blood pressure that threaten tissue function and necessitate

parenteral treatmentparenteral treatment . .

Hypercatecholamine commonly are induced by theHypercatecholamine commonly are induced by the

exaggerated effects of medication drugsexaggerated effects of medication drugs , ,

oror

food-drug interactionsfood-drug interactions . .

PostoperativePostoperative hypertension hypertension . .

Severe hypertension canSevere hypertension can

complicatecomplicate

the postoperative course after coronary and peripheral vascular proceduresthe postoperative course after coronary and peripheral vascular procedures . .

The elevated pressure threatens suture lines and promotes The elevated pressure threatens suture lines and promotes excessiveexcessive bleeding bleeding . .

PathophysiologyPathophysiology

PathophysiologyPathophysiology

Although the exact pathophysiologic mechanism is unknown, it is believed that hypertensive emergencies are triggered by an Although the exact pathophysiologic mechanism is unknown, it is believed that hypertensive emergencies are triggered by an abrupt increase in systemic vascular resistance caused by increases in circulating abrupt increase in systemic vascular resistance caused by increases in circulating vasoconsictors,vasoconsictors, norepinephrine, norepinephrine,

angiotensin II.angiotensin II.

The resulting increase inThe resulting increase in

bloodblood pressurepressure

leads toleads to

Arteriolar fibrinoid necrosis Arteriolar fibrinoid necrosis characterized bycharacterized by::

– Endothelial damage.Endothelial damage.– Fibrin deposition.Fibrin deposition.– Loss of autoregulatory function. Loss of autoregulatory function.

Ischemia and dysfunction in the target organ cause Ischemia and dysfunction in the target organ cause further release further release of vasoactive substances, producingof vasoactive substances, producing

– A cycle of increasing SVR.A cycle of increasing SVR.– Elevated systemic blood pressure.Elevated systemic blood pressure.– Decreased cardiac output.Decreased cardiac output.– Vascular injury.Vascular injury.– Tissue damage.Tissue damage.

An alternative explanation is that elevated An alternative explanation is that elevated blood pressure complicates ablood pressure complicates a

PrimaryPrimary

disease process anddisease process and

accelerates tissue injuryaccelerates tissue injury . .

The specific organ system affected defines The specific organ system affected defines the hypertensive crisisthe hypertensive crisis

– Aortic dissection.Aortic dissection.– Acute left ventricular failure.Acute left ventricular failure.– Stroke.Stroke.

AutoregulationAutoregulation

The kidney, brain, and heart all The kidney, brain, and heart all possess autoregulatory mechanisms possess autoregulatory mechanisms

that maintain blood flow at that maintain blood flow at

near constant near constant

levels despite fluctuations in blood levels despite fluctuations in blood pressure. pressure.

Because the brain is encased in a Because the brain is encased in a definit space and because it definit space and because it

maximally extracts oxygen at maximally extracts oxygen at baselinebaseline , ,

it is most vulnerable when its it is most vulnerable when its autoregulatory systems failautoregulatory systems fail . .

Excess blood flow results inExcess blood flow results in

– Cerebral edema.Cerebral edema.– Elevated intracranial pressure.Elevated intracranial pressure.– Ischemia.Ischemia.

Cerebral blood flow normally is Cerebral blood flow normally is maintained at a near-constant level maintained at a near-constant level

despite variations in cerebral perfusion despite variations in cerebral perfusion pressurepressure..

An elevated MAP causes anAn elevated MAP causes an

increaseincrease

in CPP, whereas a decreasing MAP causes in CPP, whereas a decreasing MAP causes decreaseddecreased

CPP. Despite changes in CPP, cerebral autoregulatory mechanisms maintain CBF; as MAPCPP. Despite changes in CPP, cerebral autoregulatory mechanisms maintain CBF; as MAP

rises, vasoconstrictionrises, vasoconstriction

occurs, and as MAPoccurs, and as MAP

decreases, vasodilatation decreases, vasodilatation occursoccurs..

CPP: Eerebral perfusion pressureCPP: Eerebral perfusion pressure..

This system has This system has upperupper and and lowerlower limits beyond limits beyond which CBF can no longer be controlledwhich CBF can no longer be controlled..

When CPP decreases below the lower limits of autoregulation,When CPP decreases below the lower limits of autoregulation,

brain brain hypoxiahypoxia ensues, and symptoms of ensues, and symptoms of hypoperfusion hypoperfusion manifest: manifest: – Headache.Headache.– Nausea.Nausea.– Dizziness.Dizziness.– Altered sensorium.Altered sensorium.– Lethargy. Lethargy.

If unconnected or extreme,If unconnected or extreme,

this may ultimately cause infarction.this may ultimately cause infarction.

When MAP exceeds When MAP exceeds

autoregulatory capabilities,autoregulatory capabilities, hyperperfusion hyperperfusion

occurs, leading to an increase in ICP, cerebral edema, and progressive organoccurs, leading to an increase in ICP, cerebral edema, and progressive organ

dysfunction.dysfunction.

Most persons with normal blood pressure Most persons with normal blood pressure maintain autoregulation of MAP between maintain autoregulation of MAP between

50 and 150 mm Hg50 and 150 mm Hg , ,

although this is highly variablealthough this is highly variable . .

These values generally increase These values generally increase among patients with chronic among patients with chronic

hypertensionhypertension..

These patients consequently may These patients consequently may have cerebral hypoperfusion at an have cerebral hypoperfusion at an

MAP that is considered normalMAP that is considered normal . .

– Elderly persons.Elderly persons.– Cerebrovascular accidents.Cerebrovascular accidents.– Subarachnoid hemorrhage.Subarachnoid hemorrhage.– Hypertensive encephalopathy.Hypertensive encephalopathy.– Accelerated or malignant hypertension Accelerated or malignant hypertension

have altered autoregulation.have altered autoregulation.

Treatment must be tempered by the Treatment must be tempered by the fact fact thatthat

overzealous blood pressure overzealous blood pressure reduction can lead to permanent reduction can lead to permanent

neurologic damageneurologic damage . .

– Cerebrovascular accidents.– Blindness-piaralysis.– Coma.– MI.– Death

have been reported sequences of aggressive blood pressure reduction.

PrognosisPrognosis

The prognosis of a patient who has The prognosis of a patient who has undergone hypertensive crisis and undergone hypertensive crisis and

not been treated not been treated

is is

poor. poor.

Before the introduction of effective antihypertensive agents, Before the introduction of effective antihypertensive agents,

more than 90% more than 90%

of patients with accelerated malignant hypertension died within of patients with accelerated malignant hypertension died within

1 year 1 year

of diagnosis.of diagnosis.

Modern pharmacotherapy and the availability of dialysis have substantially Modern pharmacotherapy and the availability of dialysis have substantially increased survival ratesincreased survival rates , ,

with studies reporting survival rates ofwith studies reporting survival rates of

more than 70%more than 70%

at 5-year follow-upat 5-year follow-up..

Laboratory examination and diagnostic testingLaboratory examination and diagnostic testing . .

The diagnostic evaluation must be brief becauseThe diagnostic evaluation must be brief because

time to treatment is crucialtime to treatment is crucial . .

Diagnostic imaging if clinically indicated can be performed after treatment has been institutedDiagnostic imaging if clinically indicated can be performed after treatment has been instituted..

Azotemia and hemolysis Azotemia and hemolysis

indicate indicate

an emergency.an emergency.

Blood chemistries to rule out uremia.Blood chemistries to rule out uremia.

Urinalysis to look for Urinalysis to look for – Proteinuria.Proteinuria.– Hematuria.Hematuria.– casts. casts.

Hematuria and moderate to severe proteinuria Hematuria and moderate to severe proteinuria

indicate an emergency.indicate an emergency.

Finger-stick glucose test can rule out hypoglycemia Finger-stick glucose test can rule out hypoglycemia

as a cause of changesas a cause of changes

in in

mental status.mental status.

Ischemic changes on the electrocardiogram indicateIschemic changes on the electrocardiogram indicate

an emergency.an emergency.

Pulmonary edema on chest radiography indicates anPulmonary edema on chest radiography indicates an

emergency.emergency.

Computed tomography may be Computed tomography may be needed in the setting of a needed in the setting of a

possiblepossible

cerebrovascular accident.cerebrovascular accident.

TherapyTherapy

The presence of acute or rapidly The presence of acute or rapidly progressive end-organ damage, not the progressive end-organ damage, not the

absolute blood pressure reading, absolute blood pressure reading, determines determines

whether whether

the situation is an emergency or urgency. the situation is an emergency or urgency.

This determination dictates the type of treatment This determination dictates the type of treatment – Parenteral.Parenteral.– Oral.Oral.– ICU.ICU.– Ward.Ward.– outpatient.outpatient.

For example, a blood pressure of For example, a blood pressure of

120/80 mm Hg 120/80 mm Hg

may represent a hypertensive emergencymay represent a hypertensive emergency

for a patient with aortic dissection, whereas a blood pressure of 200/120 mm Hg for a person with for a patient with aortic dissection, whereas a blood pressure of 200/120 mm Hg for a person with

asymptomatic chronic hypertension asymptomatic chronic hypertension usually does not necessitate emergency therapy. usually does not necessitate emergency therapy.

The appropriate diagnostic evaluation and The appropriate diagnostic evaluation and therapeutictherapeutic

plan also are dictated by the specific disease. plan also are dictated by the specific disease.

For example, the specific pharmacologic regimen for a For example, the specific pharmacologic regimen for a

pregnant woman pregnant woman

with preeclampsia differs from that for an with preeclampsia differs from that for an elderly man who has had a stroke. elderly man who has had a stroke.

Regardless of drug regimen, the Regardless of drug regimen, the

goal of treatment goal of treatment

is is – Break the cycle of increasing blood pressure.Break the cycle of increasing blood pressure.– Preserve cardiac output.Preserve cardiac output.– Renal blood flow.Renal blood flow.– Limit end-organ damage. Limit end-organ damage.

NeurologicNeurologic emergenciesemergencies

Patients with neurologic findings and severe hypertension present a Patients with neurologic findings and severe hypertension present a

particular challenge. particular challenge.

Neurologic emergencies can result from hypertensive emergencies or may themselves cause Neurologic emergencies can result from hypertensive emergencies or may themselves cause

markedly elevated markedly elevated

blood pressures, which may exacerbate neurologic damage. blood pressures, which may exacerbate neurologic damage.

The key differentiating point is that neurologic alterations caused by elevated blood pressure are reversed when blood pressure is controlled, whereas primary The key differentiating point is that neurologic alterations caused by elevated blood pressure are reversed when blood pressure is controlled, whereas primary neurologic disneurologic disorders orders

are not. are not.

The insidious progression of symptoms in hypertensive encephalopathy aids in differentiating hypertensive encephalopathy from cerebrovascular accidents, The insidious progression of symptoms in hypertensive encephalopathy aids in differentiating hypertensive encephalopathy from cerebrovascular accidents, which usually which usually

manifest abruptly.manifest abruptly.

Nevertheless, the diagnosis is one of exclusion because other hypertensive emergencies.Nevertheless, the diagnosis is one of exclusion because other hypertensive emergencies.– Cerebrovascular accident.Cerebrovascular accident.– Subarachnoid hemorrhage.Subarachnoid hemorrhage.– Intraparenchymal bleeding.Intraparenchymal bleeding.– Primary seizure disorder.Primary seizure disorder.

Share many symptoms and signs. Share many symptoms and signs.

Evaluation often necessitates further diagnostic

imaging, such as CT, and consultation with a neurologist.

HypertensiveHypertensive emergenciesemergencies

The goal of therapy is immediate, controlledThe goal of therapy is immediate, controlled

reduction in blood pressure. reduction in blood pressure.

toxic side effects of antihypertensive agents must be understood and anticipated.toxic side effects of antihypertensive agents must be understood and anticipated.

Patients are Patients are

treated in an ICU, where clinical treated in an ICU, where clinical status and vital signs canstatus and vital signs can

be constantly monitored with the aid be constantly monitored with the aid of an arterial line.of an arterial line.

Attention is focused on the status of Attention is focused on the status of airway, breathing, and circulation (ABCs). Ancillary measures such as airway, breathing, and circulation (ABCs). Ancillary measures such as intubation and dialysis are instituted if necessary.intubation and dialysis are instituted if necessary.

Blood pressure is reduced in a Blood pressure is reduced in a

controlled, predictable manner. controlled, predictable manner.

The lower limit of autoregulation among persons with normal blood pressure The lower limit of autoregulation among persons with normal blood pressure

and those with hypertension is approximately and those with hypertension is approximately

25% of MAP. 25% of MAP.

It is recommended that blood pressure initially be reduced by no more than 25% of MAP over minutes to hours and that further reductions occur It is recommended that blood pressure initially be reduced by no more than 25% of MAP over minutes to hours and that further reductions occur

over days to weeks over days to weeks

toto

allow the autoregulatory mechanisms to reset. allow the autoregulatory mechanisms to reset.

Exceptions include.Exceptions include.

– Aortic dissection.Aortic dissection.– Left ventricular failure.Left ventricular failure.– Pulmonary edema.Pulmonary edema.

which demand more aggressive blood pressure reduction to limit tissue damage. which demand more aggressive blood pressure reduction to limit tissue damage.

Specific antihypertensive therapy is tailored to the underlying disease Specific antihypertensive therapy is tailored to the underlying disease

asas

aortic dissectionaortic dissection

anginaangina

Diagnosis and treatment are reassessed if the clinical condition, Diagnosis and treatment are reassessed if the clinical condition,

especially neurologic status, deterioratesespecially neurologic status, deteriorates

with reduction of blood pressure.with reduction of blood pressure.

Medical therapy. Medical therapy.

A number of parenteral antihypertensive medications are available to manage A number of parenteral antihypertensive medications are available to manage hypertensive emergencies. hypertensive emergencies.

The specific clinical scenario dictates the agents used. The specific clinical scenario dictates the agents used.

Characteristics of an ideal agent includeCharacteristics of an ideal agent include

– Rapid onset.Rapid onset.– Cessation of action.Cessation of action.– A predictable dose-response curveA predictable dose-response curve– Minimal side effects.Minimal side effects.

Patients with hypertensive emergencies have Patients with hypertensive emergencies have

– Excessive elevations in SVR.Excessive elevations in SVR.– Decreased cardiac output.Decreased cardiac output.– Decreased renal blood flow.Decreased renal blood flow.– Volume depletion. Volume depletion.

The most useful agents are vasodilating agents such as The most useful agents are vasodilating agents such as

nitroprusside.nitroprusside.

Diuretics and beta-blockers are Diuretics and beta-blockers are

avoidedavoided

unless the patient has unless the patient has – Aortic dissection.Aortic dissection.– MI.MI.– Pulmonary edema.Pulmonary edema.

For hypertensive encephalopathy, cerebrovascular accidents, For hypertensive encephalopathy, cerebrovascular accidents,

or other conditions in which mental status must be monitored, agents that have prominent CNS side effects or other conditions in which mental status must be monitored, agents that have prominent CNS side effects

as sedation as sedation

are avoided.are avoided.

For conditions associated with elevated ICP, such as For conditions associated with elevated ICP, such as

– Cerebrovascular accident. Cerebrovascular accident. – Subarachnoid hemorrhage.Subarachnoid hemorrhage.– Hypertensive encephalopathy.Hypertensive encephalopathy.

Agents that directly increase CBF are avoided.Agents that directly increase CBF are avoided.

The agent selected has the most favorable hemodynamic and side effect profile on the basis of the specific hypertensive The agent selected has the most favorable hemodynamic and side effect profile on the basis of the specific hypertensive emergency. emergency.

The drug of choice for most hypertensive crises is The drug of choice for most hypertensive crises is

sodium nitroprusside. sodium nitroprusside.

Effective alternatives include Effective alternatives include

labetalollabetalol

in certain circumstances, in certain circumstances,

nitroglycerinnitroglycerin or or hydralazinehydralazine

may be preferred.may be preferred.

Sodium nitroprusside is the drug of choice for most Sodium nitroprusside is the drug of choice for most hypertensive emergencies. hypertensive emergencies.

– The favorable hemodynamic profile.The favorable hemodynamic profile.– Rapid onset.Rapid onset.– Rapid cessation of action of sodium nitroprusside.Rapid cessation of action of sodium nitroprusside.

Make it the preferred parenteral agent for most emergencies. Make it the preferred parenteral agent for most emergencies.

A potent, direct vascular smooth muscle relaxant, sodium nitroprusside decreases afterload and preload A potent, direct vascular smooth muscle relaxant, sodium nitroprusside decreases afterload and preload

by by

dilating arteriolesdilating arterioles

and and

increasing venous capacitance.increasing venous capacitance.

Hemodynamic effects include a Hemodynamic effects include a

decrease in decrease in – MAP.MAP.– AfterloadAfterload– PreloadPreload

an increase or no change inan increase or no change in– Cardiac outputCardiac output– Increased Increased – Renal blood flow Renal blood flow – Glomerular filtration rate. Glomerular filtration rate.

Although the direct action of sodium nitroprusside on the cerebral vasculature may cause increased cerebral perfusion, this is Although the direct action of sodium nitroprusside on the cerebral vasculature may cause increased cerebral perfusion, this is

counteracted by counteracted by

a potent effect on MAP. a potent effect on MAP.

Most patients with neurologic crisis who need blood pressure control tolerate sodium nitroprusside without a worsening of Most patients with neurologic crisis who need blood pressure control tolerate sodium nitroprusside without a worsening of neurologic status. neurologic status.

However, the possibility of an increase in ICP and further clinical deterioration despite a decrease in MAP must be However, the possibility of an increase in ICP and further clinical deterioration despite a decrease in MAP must be

kept in mind kept in mind

as a potential side effect in patients with severely increased ICP.as a potential side effect in patients with severely increased ICP.

Administration. Administration.

Sodium nitroprusside must be administered by means of Sodium nitroprusside must be administered by means of

constant intravenous infusionconstant intravenous infusion

in an intensive care setting in an intensive care setting

with with

constant monitoring of arterial blood pressure. constant monitoring of arterial blood pressure.

It has a rapid onset of action, and its effect ceases It has a rapid onset of action, and its effect ceases

within 1 to 5 minutes within 1 to 5 minutes

of cessation of infusion.of cessation of infusion.

Side effects. Side effects.

Red blood cells and muscle cells Red blood cells and muscle cells

MetabolizeMetabolize

sodium nitroprusside to sodium nitroprusside to

cyanidecyanide

which is converted to which is converted to

thiocyanatethiocyanate

in the liver and excreted in the urine. in the liver and excreted in the urine.

Thiocyanate Thiocyanate levels rise in patients with levels rise in patients with renal insufficiency, renal insufficiency,

and cyanide accumulates in patients and cyanide accumulates in patients

with with

hepatic disease.hepatic disease.

Signs of thiocyanate toxicity include Signs of thiocyanate toxicity include

- Nausea.- Nausea. -Vomiting.-Vomiting.

- Headache. - Headache. - Fatigue.- Fatigue.

- Delirium.- Delirium. - Muscle spasms.- Muscle spasms.

- Tinnitus- Tinnitus - Seizures. - Seizures.

Monitoring for signs and symptoms of toxicity and maintaining thiocyanate levels Monitoring for signs and symptoms of toxicity and maintaining thiocyanate levels less than 12 mg/dL less than 12 mg/dL

allow safe use of sodium nitroprusside.allow safe use of sodium nitroprusside.

LabetalolLabetalol

is useful in most hypertensive crises. The main disadvantage is its relatively is useful in most hypertensive crises. The main disadvantage is its relatively

long duration of action. long duration of action.

Labetalol is an Labetalol is an

alpha-blocker alpha-blocker

andand

Nonselective beta-blocker with partial B2 agonist activity. Nonselective beta-blocker with partial B2 agonist activity.

When given through continuous intravenous infusion, the relative beta- to alpha-blocking When given through continuous intravenous infusion, the relative beta- to alpha-blocking

EffectEffect

of labetalol is 7 : 1.of labetalol is 7 : 1.

The hemodynamic effects of labetalol include The hemodynamic effects of labetalol include

decrease in decrease in – SVE.SVE.– MAP.MAP.– Heart rate. Heart rate.

a decrease or no change ina decrease or no change in– Cardiac output. Cardiac output.

Labetalol has little direct effect on cerebral vasculature, Labetalol has little direct effect on cerebral vasculature,

does not increase ICPdoes not increase ICP

and is considered by some to be the and is considered by some to be the

drug of choice drug of choice

in situations characterized by markedly elevated ICP. in situations characterized by markedly elevated ICP.

Labetalol begins to lower blood pressure within Labetalol begins to lower blood pressure within 5 minutes, 5 minutes,

and its effects can lastand its effects can last

1 to 3 hours after cessation of the infusion. 1 to 3 hours after cessation of the infusion.

Contraindications. Contraindications.

Labetalol is contraindicated for patients withLabetalol is contraindicated for patients with – Congestive heart failure.Congestive heart failure.– Bradycardia.Bradycardia.– Heart block more than first degree.Heart block more than first degree.– Reactive airway disease.Reactive airway disease.

Nitroglycerin is considered the drug of choice for managing hypertension in the setting of Nitroglycerin is considered the drug of choice for managing hypertension in the setting of

– Myocardial ischemia.Myocardial ischemia.– Acute MI.Acute MI.– Pulmonary edema.Pulmonary edema.– After coronary artery bypass grafting. After coronary artery bypass grafting.

The role of intravenous nitroglycerin therapy is limited to hypertension complicating The role of intravenous nitroglycerin therapy is limited to hypertension complicating

– Myocardial ischemia.Myocardial ischemia.– MI.MI.– Congestive heart failure. Congestive heart failure.

Nitroglycerin is primarily a venodilator and has modest effects on afterload Nitroglycerin is primarily a venodilator and has modest effects on afterload

at high doses.at high doses.

The decrease in preload and afterload decreases The decrease in preload and afterload decreases

myocardial oxygen demand. myocardial oxygen demand.

Nitroglycerin also Nitroglycerin also

– Dilates the epicardial coronary arteries.Dilates the epicardial coronary arteries.– Inhibits vasospasm.Inhibits vasospasm.– Favorably redistributes blood flow to the endocardium.Favorably redistributes blood flow to the endocardium.

Nitroglycerin directly increases CBF and is Nitroglycerin directly increases CBF and is not used in not used in situations characterized by high ICP.situations characterized by high ICP.

FenoldopamFenoldopam

Is a selective peripheral dopamine-1-receptor agonist approved for Is a selective peripheral dopamine-1-receptor agonist approved for

the management of severe hypertension. Fenoldopam is an arterial vasodilator with a rapid onset of action and a relatively the management of severe hypertension. Fenoldopam is an arterial vasodilator with a rapid onset of action and a relatively short half-life when administered intravenously. short half-life when administered intravenously.

It may be of particular benefit It may be of particular benefit

in patients with in patients with

renal insufficiency renal insufficiency

as it has been shown to improve renal perfusion. as it has been shown to improve renal perfusion.

Fenoldopam may cause a reflex Fenoldopam may cause a reflex tachycardia, tachycardia,

which can be blunted by the which can be blunted by the

concomitant use of a beta-blocker.concomitant use of a beta-blocker.

Fenoldopam is contraindicated in Fenoldopam is contraindicated in

patients with patients with

glaucoma glaucoma

because it can increase intraocular pressure.because it can increase intraocular pressure.

HydralazineHydralazine

The role of intravenous hydralazine is limited to the treatment of pregnant women with The role of intravenous hydralazine is limited to the treatment of pregnant women with

preeclampsia. preeclampsia.

Hydralazine is a direct arterial vasodilator with no effect on venous capacitance. It Hydralazine is a direct arterial vasodilator with no effect on venous capacitance. It crosses the uteroplacental barrier but has crosses the uteroplacental barrier but has minimal effects on the fetus. minimal effects on the fetus.

It is usually administered in boluses of 10 to 20 mg and has a long duration of action. It is usually administered in boluses of 10 to 20 mg and has a long duration of action.

– Hydralazine decreases SVR.Hydralazine decreases SVR.– Induces compensatory tachycardia.Induces compensatory tachycardia.– Increases ICP. Increases ICP.

It can exacerbate angina and is contraindicated in the care of patients with It can exacerbate angina and is contraindicated in the care of patients with – Ongoing coronary ischemia.Ongoing coronary ischemia.– Aortic dissection.Aortic dissection.– Increased ICP.Increased ICP.

Management of specific emergenciesManagement of specific emergencies

Accelerated or malignant hypertensionAccelerated or malignant hypertension

In the acute phase, the pharmacologic agent of choice is In the acute phase, the pharmacologic agent of choice is sodium nitroprusside. Labetalol is an effective alternative.sodium nitroprusside. Labetalol is an effective alternative.

Because patients usually have marked elevations of SVR and volume depletion, Because patients usually have marked elevations of SVR and volume depletion, diuretics are contraindicated. diuretics are contraindicated.

Hypertensive encephalopathyHypertensive encephalopathy

The treatment of choice is sodium nitroprusside or labetalol. The treatment of choice is sodium nitroprusside or labetalol.

Agents that depress the sensorium or increase ICP are avoided.Agents that depress the sensorium or increase ICP are avoided.

Most patients with hypertensive encephalopathy Most patients with hypertensive encephalopathy

improve within hours improve within hours

of blood pressure reductionof blood pressure reduction

If there is no improvement despite a decrease in blood pressure, the If there is no improvement despite a decrease in blood pressure, the

diagnosis must be reconsidered.diagnosis must be reconsidered.

Neurologic complications includeNeurologic complications include

– Cerebrovascular accident.Cerebrovascular accident.– Embolie stroke.Embolie stroke.– Intraparenchymal hemorrhage.Intraparenchymal hemorrhage.– Subarachnoid hemorrhage.Subarachnoid hemorrhage.

Extreme caution Extreme caution

Must be exercised when lowering even markedly elevated blood pressures in the setting of a cerebrovascular accident.Must be exercised when lowering even markedly elevated blood pressures in the setting of a cerebrovascular accident.

Elevated ICP caused by cerebral edema or intraparenchymal hemorrhage increases the MAP needed to adequately perfuse the brain Elevated ICP caused by cerebral edema or intraparenchymal hemorrhage increases the MAP needed to adequately perfuse the brain

CPP = MAP - ICP. CPP = MAP - ICP.

Subarachnoid hemorrhage is characterized by intense vasospasm at and adjacent to the site of rupture. Reduction of blood pressure in these circumstances Subarachnoid hemorrhage is characterized by intense vasospasm at and adjacent to the site of rupture. Reduction of blood pressure in these circumstances

may cause may cause

global global

or in the case of subarachnoid hemorrhage or in the case of subarachnoid hemorrhage focal hypoperfusion.focal hypoperfusion.

Markedly elevated blood pressures, however, may increase risk for Markedly elevated blood pressures, however, may increase risk for

rebleeding in subarachnoid hemorrhage or extend a hemorrhagic infarct.rebleeding in subarachnoid hemorrhage or extend a hemorrhagic infarct.

Lesions that are potentially surgically correctable such as sub-arachnoid hemorrhage and neoplasms must be identified.

Management of markedly elevated blood pressure in the setting of cerebrovascular accident or subarachnoid hemorrhage is Management of markedly elevated blood pressure in the setting of cerebrovascular accident or subarachnoid hemorrhage is tempered by tempered by

concerns about further reducing blood flow to underperfused areas of the brain.concerns about further reducing blood flow to underperfused areas of the brain.

The following The following

guidelines are suggested.guidelines are suggested.

When blood pressure is less than 180/105 mm Hg, When blood pressure is less than 180/105 mm Hg,

no treatment is recommended.no treatment is recommended.

When blood pressure is 180/105 to 230/120 mm Hg for longer than 60 minutes, When blood pressure is 180/105 to 230/120 mm Hg for longer than 60 minutes, treatment is started.treatment is started.

When treatment is indicated, it must be closely monitored, When treatment is indicated, it must be closely monitored, often with direct ICP monitor.often with direct ICP monitor.

Target blood pressures areTarget blood pressures are

160/100 to 175/110 mm Hg for patients who had normal blood pressure and 160/100 to 175/110 mm Hg for patients who had normal blood pressure and

180/110 to 185/120 mm Hg for persons with chronic hypertension.180/110 to 185/120 mm Hg for persons with chronic hypertension.

The drug of choice is labetalol or sodium nitroprusside.The drug of choice is labetalol or sodium nitroprusside.

Nimodipine Nimodipine

A calcium channel blocker with modest antihypertensive effect, has been beneficial in the management of subarachnoid hemorrhage. A calcium channel blocker with modest antihypertensive effect, has been beneficial in the management of subarachnoid hemorrhage.

If blood pressure remains higher than desired despite use of nimodipine, therapy sodium nitroprusside or labetalol If blood pressure remains higher than desired despite use of nimodipine, therapy sodium nitroprusside or labetalol

may be considered.may be considered.

Agents that directly increase CPP and therefore ICP are avoided. Agents that directly increase CPP and therefore ICP are avoided.

Aortic dissection is an emergency. Aortic dissection is an emergency.

Blood pressure must be lowered immediately. Blood pressure must be lowered immediately.

Patients with type A dissection have a mortality rate of 1% per hour in the first 48 hours Patients with type A dissection have a mortality rate of 1% per hour in the first 48 hours

unless medical therapyunless medical therapy

is instituted and the patient is referred for emergency surgical intervention. is instituted and the patient is referred for emergency surgical intervention.

Antihypertensive therapy is the treatment of choice for type B dissection. Antihypertensive therapy is the treatment of choice for type B dissection.

Labetalol or the combination of sodium nitroprusside with a beta-blocker is the treatment of choice. Labetalol or the combination of sodium nitroprusside with a beta-blocker is the treatment of choice.

Aggressive blood pressure reduction is indicated even for patients with normal blood pressure because Aggressive blood pressure reduction is indicated even for patients with normal blood pressure because

shear force shear force and and afterloadafterload

must be reduced to limit tissue damage. must be reduced to limit tissue damage.

A reasonable goal is a MAP of approximately 70 mm Hg.A reasonable goal is a MAP of approximately 70 mm Hg.

Drugs that decrease afterload and induce compensatory tachycardia are contraindicated. Drugs that decrease afterload and induce compensatory tachycardia are contraindicated.

Left ventricular failure or pulmonary edema. Left ventricular failure or pulmonary edema.

Treatment is best accomplished with sodium nitroprusside and small doses of diuretics. Treatment is best accomplished with sodium nitroprusside and small doses of diuretics.

Nitroglycerin is an effective alternative, especially if ischemia is present. Nitroglycerin is an effective alternative, especially if ischemia is present.

Sodium nitroprusside and nitroglycerin often are used concomitantly. Sodium nitroprusside and nitroglycerin often are used concomitantly.

Beta-Blockers and calcium channel blockers must be avoided in the decompensated state.Beta-Blockers and calcium channel blockers must be avoided in the decompensated state.

Myocardial ischemia. Myocardial ischemia.

Blood pressure reduction with nitrates and beta-blockers is the treatment of choice. Blood pressure reduction with nitrates and beta-blockers is the treatment of choice.

Sodium nitroprusside is added if further blood pressure reduction is required. Reperfusion and antithrombotic Sodium nitroprusside is added if further blood pressure reduction is required. Reperfusion and antithrombotic

therapy are the mainstays of management of therapy are the mainstays of management of acute MI acute MI and and unstable angina. unstable angina.

Hypertensive crisis associated with hypercatecholaminemia. Hypertensive crisis associated with hypercatecholaminemia.

The pharmacologic agents of choice include sodium nitroprusside, labetalol, or calcium channel blockers. The pharmacologic agents of choice include sodium nitroprusside, labetalol, or calcium channel blockers.

Phentolamine can be useful in cases of pheochromocytoma. Phentolamine can be useful in cases of pheochromocytoma.

Beta-Blockers must be avoided, because they can cause a paradoxical increase in blood pressure because of the effects of Beta-Blockers must be avoided, because they can cause a paradoxical increase in blood pressure because of the effects of unopposedunopposed

alpha-receptor stimulation.alpha-receptor stimulation.

Postoperative hypertension. Postoperative hypertension.

Parenteral treatment with sodium nitroprusside or labetalol is Parenteral treatment with sodium nitroprusside or labetalol is

preferred. preferred.

After After

coronary bypass grafting, coronary bypass grafting,

nitroglycerin is considered the initial drug of choice.nitroglycerin is considered the initial drug of choice.

Hypertensive urgencies. Hypertensive urgencies.

Most patients diagnosed with hypertensive urgency actually Most patients diagnosed with hypertensive urgency actually

have severe hypertensionhave severe hypertension

and are and are

notnot

in any immediate danger of progressing to hypertensive emergency. in any immediate danger of progressing to hypertensive emergency.

They are often persons with chronic hypertension who are They are often persons with chronic hypertension who are

suboptimally treated or noncompliant. suboptimally treated or noncompliant.

Priority of therapyPriority of therapy

Hypertensive urgencies usually can be managed with oral Hypertensive urgencies usually can be managed with oral medication without admission to the hospital. medication without admission to the hospital.

End-organ damage is not imminent, and blood pressure can be modestly lowered over a period of hours as long as adequate follow-up care is ensured. End-organ damage is not imminent, and blood pressure can be modestly lowered over a period of hours as long as adequate follow-up care is ensured.

The great danger lies in overtreating these patients and inciting a hypotensive crisis.The great danger lies in overtreating these patients and inciting a hypotensive crisis.

Sometimes, placing the patient in a quiet, calm environment can decrease blood pressure to a less alarming level. Sometimes, placing the patient in a quiet, calm environment can decrease blood pressure to a less alarming level.

If the blood pressure is still markedly elevated, reinstitution or enhancement of prior therapy often is effective.If the blood pressure is still markedly elevated, reinstitution or enhancement of prior therapy often is effective.

MAP is not decreased more than MAP is not decreased more than

15% to 20%. 15% to 20%.

Lower initial doses of antihypertensive medications are used to treat patients with cerebrovascular disease or Lower initial doses of antihypertensive medications are used to treat patients with cerebrovascular disease or

coronary artery disease who are coronary artery disease who are

taking antihypertensivetaking antihypertensive

drugs or who drugs or who

are volume depleted. are volume depleted.

These patients tend to have exaggerated responses to drug therapy. They also are especially These patients tend to have exaggerated responses to drug therapy. They also are especially

vulnerablevulnerable

to hypotension. to hypotension.

Lower doses of medications must be used. Monitoring for 4 to 6 hours is necessary to judge treatment effect and look for Lower doses of medications must be used. Monitoring for 4 to 6 hours is necessary to judge treatment effect and look for complications. complications.

Urgent follow-up care is mandatory within 24 hours. Urgent follow-up care is mandatory within 24 hours.

Evaluation for secondary causes of hypertension is indicated. Evaluation for secondary causes of hypertension is indicated.

Drug therapy. Drug therapy.

Oral agents used to manage hypertensive urgencies. Oral agents used to manage hypertensive urgencies.

The drugs of choice include The drugs of choice include

– Captopril.Captopril.– ClonidineClonidine– Oral labetalol.Oral labetalol.

CaptoprilCaptopril

Considered by some to be the drug of choice, captopril is the fastest-actingConsidered by some to be the drug of choice, captopril is the fastest-acting

oral angiotensin-converting oral angiotensin-converting

enzyme inhibitor. enzyme inhibitor.

At small doses, it rarely causes marked hypotension, although this potential exists in patients who are markedly volume At small doses, it rarely causes marked hypotension, although this potential exists in patients who are markedly volume depleted or who have renal artery stenosis. depleted or who have renal artery stenosis.

Captopril begins to Captopril begins to work within work within 15 to 30 minutes of ingestion and has a 4- to 6-hour duration of activity. 15 to 30 minutes of ingestion and has a 4- to 6-hour duration of activity.

Caution is advised in the treatment of patients with marked renal insufficiency or volume depletion.Caution is advised in the treatment of patients with marked renal insufficiency or volume depletion.

ClonidineClonidine

acts through central alpha-agonist activity. acts through central alpha-agonist activity.

It has been administered in repeated hourly doses and safely lowers blood pressure over a period of hours. It has been administered in repeated hourly doses and safely lowers blood pressure over a period of hours.

Untoward effects, include sedation and rebound hypertension. Untoward effects, include sedation and rebound hypertension.

Clonidine is not administered to anyone with altered sensorium or who may not Clonidine is not administered to anyone with altered sensorium or who may not comply comply

with treatment.with treatment.

Labetalol Labetalol ““A combined alpha- and beta-blocker”, labetalol taken orally has a relative beta- to alpha-blocking effect of approximately 3:1. Dosage begins at 100 mg (taken A combined alpha- and beta-blocker”, labetalol taken orally has a relative beta- to alpha-blocking effect of approximately 3:1. Dosage begins at 100 mg (taken

orally twice daily) and is titrated to the desired response. orally twice daily) and is titrated to the desired response.

The onset of action is 30 minutes to 2 hours after administration; the duration of action is 8 to 12 hours.The onset of action is 30 minutes to 2 hours after administration; the duration of action is 8 to 12 hours.

Nifedipine. Nifedipine.

The use of sublingual nifedipine has been reported to cause The use of sublingual nifedipine has been reported to cause – Hypotension.Hypotension.– Syncope.Syncope.– Transient ischemic attacks.Transient ischemic attacks.– Cerebrovascular accidents.Cerebrovascular accidents.– Myocardial ischemia.Myocardial ischemia.– Infarction. Infarction.

Sublingual nifedipine Sublingual nifedipine

should not be used should not be used

in the treatment of patients with hypertension.in the treatment of patients with hypertension.

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