Transcript elevated blood pressure

Hypertension Crisis
Case Scenario
A 50-year-old man with a long history of hypertension presents to
the ED with the complaints of headache for 2 days. He has not
taken his antihypertensive medications in more than a year and
does not remember their names. His physical examination is
remarkable only for a persistent blood pressure of 210/120 mm Hg
and grade I retinopathy.
Important Questions
• Is this patient stable?
• Is further workup indicated, and if so, what?
• Does the patient require immediate intervention, and if so,
what should be done?
• Does the patient require admission or monitoring, or if
discharged, how soon should he be seen in follow-up?
Hypertension
• Hypertension affects over one billion people
worldwide.
• One third of hypertensive patients remain undiagnosed.
• Despite the availability of effective antihypertensive
therapies, two thirds of hypertensive patients fail to
achieve satisfactory control
• Hypertension-related Emergency Department (ED) visits
may account for over one quarter of all acute medical
emergencies in busy urban
Stratification of hypertensive crises
• Severely elevated blood pressure is defined as a systolic blood
pressure (SBP) greater than 180 mmHg or diastolic blood pressure
(DBP) of over 120 mmHg
•
This arbitrary cutoff is of little relevance to the emergency
physician because the majority of these patients do not require
emergent blood pressure reduction misleading.
• Despite the common practice of treating severely increased blood
pressure in asymptomatic ED patients there are no supporting data
• Any given person's risk of a near-term complication of
an increased blood pressure is multifactorial;
age, chronicity of disease, rapidity of blood pressure
increase, and type of previous end-organ disease
are more important considerations than the actual
severity of hypertension .
• Accelerated hypertension is defined as severely
elevated blood pressure associated with grade-3
retinopathy on fundoscopy.
• Malignant hypertension denotes the presence of
papilledema.
Hypertension Crisis : Pathogenesis
•
Hypertension primarily affects the heart, brain, kidneys,
and large arteries, referred to as the “target organs”
•
Cerebral perfusion pressure remains constant despite fluctuations in MAP
•
Normally, CBF remains fairly constant for a MAP from 60 to up to 150
•
In chronically hypertensive pts, the lower limit of autoregulation
increased
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The observation that the lower limit of the autoregulation curve
tends to be approximately 25% of MAP
It is recommended that MAP be acutely decrease by no more than 20-25%
Changes in Joint National Committee
Classification of blood pressure
Systolic
JNC VI
<120
<130
130-139
140-159
160-179
≥180
Diastolic
<80
<85
85-89
90-99
100-109
>110
Category
Optimal
Normal
High normal
Stage 1 (mild)
Stage 2 (moderate)
Stage 3 (severe)
Hypertension Crisis : Classification
• Hypertensive emergencies
• Hypertensive urgencies
• Uncontrolled Severe Hypertension:
Acute hypertension episode
Transient hypertension
Emergent Hypertension
• A hypertensive emergency is the rapid decompensation of vital organ function
caused by an inappropriate increased blood pressure requiring immediate blood
pressure reduction
• key symptomatic manifestations of the syndrome vary widely, depending on the
target organ involvement.
•
The major target organs in hypertensive emergency are the brain, heart and
great vessels, kidney, and the gravid uterus.
• In practical terms, hypertensive emergencies are thought to require immediate
(within 1 to 2 hours) decreasing of the blood pressure
• True hypertensive emergencies are very rare
End Organ damage associated with
hypertensive emergency
• One recent study by Zampaglione and
colleagues found;
-single-organ involvement in 83%,
-two-organ involvement in 14%,
-three or more organ involvement in only 3%
of hypertensive emergencies.
The relative frequency of
end-organ involvement in
hypertensive emergency
End-organ damage type
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Cases (%)
Cerebral infarction
24.5
Intracerebral or subarachnoid bleed
4.5
Hypertensive encephalopathy
16.3
Acute pulmonary edema
22.5
Acute congestive heart failure
14.3
Acute myocardial infarction or unstable angina
Aortic dissection
2.0
Eclampasia
2.0
12.0
Data from Zampaglione B, Pascale C, Marchisio M, et al. Hypertensive urgencies and emergencies.
Prevalence and clinical presentation. Hypertension 1996;27:144–7.
Urgent Hypertension
• severely increased blood pressure in a patient at high risk
for rapidly progressive end-organ damage but without
evidence of new injury
• this is probably the most difficult category of patient to
identify within the ED.
• High risk would include patients with a history of prior
target-organ disease, such as congestive heart failure,
unstable angina, coronary artery disease, renal insufficiency,
transient ischemic attack, or stroke
• Patients in this category should receive an increased level of
scrutiny greater than that of most asymptomatic
hypertensive patients
Urgent Hypertension
• Urgent initiation of oral therapy and perhaps even a
period of inpatient observation may be warranted
• Urgencies also encompass patients with severe perioperative hypertension and the hypertensive
pregnant patient without proteinuria or signs of preeclampsia
Uncontrolled Severe Hypertension
• In the patient with asymptomatic increased blood pressure with no evidence of
target-organ disease, the most important intervention is to ensure proper followup
• TRANSEINT HYPERTENSION:
When the increased blood pressure might be the artifact of a systemic process,
such as pain or infection, the best strategy is to refer the patient for reevaluation
of the blood pressure once the primary problem has resolved
• ACUTE HYPERTENSION EPISODE(stage 3):
If the patient has discontinued his or her blood pressure medications, the
regimen should be restarted, barriers to compliance should be evaluated, and a
primary care physician should be contacted to ensure reevaluation in a week
CLINICAL EVALUATION
History
• symptoms of target organ compromise, including headache,
chest pain, dyspnea, interscapular pain, visual disturbance,
and altered mental status.
• the duration and severity of pre-existing hypertension
• the quality of blood pressure control, compliance,
• the presence of previous end-organ damage.
•
The patient's current medications
( the use of monoamine oxidase inhibitors and any illicit
drugs)
CLINICAL EVALUATION
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Physical examination
should focus on the commonly affected target organs:
Retina, Heart, Brain, Kidneys,
seeking evidence of acute or chronic injury.
Fundoscopic examination is important, looking in particular for the
presence of new hemorrhages, hard exudates, or papilledema.
Evidence of cardiovascular compromise includes signs of
pulmonary edema (S3, pulmonary rales, and elevated jugular venous
pressure) or signs of aortic dissection (pulse discrepancy among limbs
and new aortic regurgitation murmur).
Neurologic assessment should include mental status, visual
fields, and focal neurologic signs to exclude hypertensive
encephalopathy, intracranial hemorrhage, and acute ischemic stroke.
Paraclinical Study
• CBC, electrolytes, BUN, Cr level, and a urinalysis are valuable first-line
investigations.
• chest radiography For those with chest/back pain or shortness of breath,
findings of mediastinal widening or pulmonary edema should be sought.
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12-lead ECG should be obtained and examined for evidence of myocardial
ischemia or hypertrophy. The ECG has been shown to be abnormal in over 20% of
asymptomatic ED patients who have a DBP> 115 mmHg
•
CT of the head is indicated in patients who have altered mental status or focal
neurologic signs.
• If there is a suspicion of illicit drug use, urine toxicology for cocaine and
amphetamines may be helpful in confirming the diagnosis.
OVERVIEW OF TREATMENT OF HYPERTENSIVE EMERGENCY
• Promptly initiate goal-directed pharmacologic therapy with readily
available agents, often before the diagnostic workup is completed.
• Ensure that the involved critical staff is familiar with dose ranges,
infusion techniques, blood pressure monitoring requirements, and
side effects of the medications used.
•
Be mindful of practical considerations influencing the choice of
pharmacologic therapy, including the need to transport the patient to
multiple locations (emergency department, diagnostic radiology,
operating room)
• Always remember to “first, do no harm.” Do not hypoperfuse already
ischemic organs; avoid rapid swings of blood pressure beyond the
already dysfunctional range
Treatment of Hypertensive Emergencies
• The ideal drug for treating hypertensive emergencies
would have a 1-rapid onset,2- rapid maximal effect, and 3rapid offset for easy titration of blood pressure
• These characteristics are only found in parenteral agents
• Most popular drugs are Nitroprusside, Nicardipine,
Hydralazine, Labetalol, Esmolol, Phentolamine,
Enlaprilat, Fenoldopam
Specific Settings in Hypertensive Emergencies
• Hypertensive Encephalopathy
• Cerebrovascular hypertensive emergencies
• Hypertensive crisis in acute coronary syndrome
• Hypetensive crisis in aortic dissection
Hypertensive Encephalopathy
• Results from hyperperfusion of the brain when the upper limit
of cerebral autoperfusion is exceeded, resulting in cerebral
edema, petechial hemorrhages, and microinfarcts
• Symptoms; severe headache, nausea, vomiting, visual
disturbances, confusion, and focal or generalized weakness.
• Signs; disorientation, seizures, and focal neurologic signs.
Neuroimaging is important to rule out other intracranial
pathology such as intracerebral or subarachnoid bleeding
•
is reversible with the reduction of blood pressure, but if it is
left untreated, it may result in coma and even death.
SUBARACHNOID HEMORRHAGE
• the management of blood pressure must balance the risk of
re-bleeding with the risk of cerebral ischemia
• It is not recommended for routine blood pressure reduction
because of a high incidence in transient hypotension
• The patient's cognitive status may be a useful guide to the
state of cerebral perfusion pressure
•
The management of patients who have a severely impaired
level of consciousness should be more circumspect.
• Direct ICP monitoring allows MAP to be titrated with greater
precision in these cases.
INTRACEREBRAL HEMORRHAGE
• blood pressure rise tends to be more severe and less likely to resolve
spontaneously compared with hypertension following cerebral infarction
• An elevated blood pressure immediately after ICH is associated with
hematoma expansion and poorer outcomes
• Controversy remains, and the current guidelines from the American Heart
Association (AHA) recommend decreasing the blood pressure when the MAP
is greater than 130 mmHg or when the SBP is greater than 220 mmHg and
DBP>120.
intravenous esmolol or labetalol is the agent of choice. Intravenous
nitroprusside should be considered to be a second-line agent because of the
risk of increasing ICP.
ACUTE ISCHEMIC STROKE
• The elevation in arterial blood pressure occurs in over 80% of all
acute ischemic strokes
• Expectant management may be most appropriate
•
Current AIS guidelines from the AHA recommend that BP be
reduced only if the SBP > 220 mmHg, or the DBP> 120 mmHg, or if
there is evidence of end-organ damage believed to be related to
the elevation
in blood pressure
• labetolol or sodium nitroprusside is the agent suggested
• Patients who are being considered for thrombolysis must have a
blood pressure less than 185/110 mmHg,
• labetolol is the agent recommended to achieve and maintain this
goal
AORTIC DISSECTION
The immediate reduction in blood pressure is essential to
limit the extent of dissection while surgical treatment is being
considered or arranged
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• Initial therapeutic goals should include the elimination of pain
and reduction of systolic blood pressure to 100 to 120 mmHg
or the lowest level commensurate with adequate vital organ
perfusion.
• At first rate control then blood pressure.
•
• Sodium nitroprusside used in combination with a β-blocker
such as propranolol is a good first-line therapy. Labetalol is an
excellent alternative because it combines ɑ- and β-adrenergic
receptor blocking properties,
MYOCARDIAL ISCHEMIA OR INFARCTION
• ACS may be complicated by hypertension because of pain,
anxiety, and increased sympathetic tone.
• ↑BP increases afterload, resulting in greater myocardial work
and oxygen requirements.
In addition, increased wall stress is associated with
impairment of subendocardial tissue perfusion,leading
further imbalance in myocardial oxygen supply and demand.
•
β-blockers are the antihypertensive of choice
they reduce heart rate and blood pressure while also
elevating the threshold for ventricular fibrillation.
Nitroglycerin is a useful adjunct for patients who have
ongoing pain, especially if blood pressure remains elevated.
Beta-blockers and ACE inhibitors have been shown to reduce
mortality in patients who have myocardial infarction
Hypertensive Urgency and severe HTN
management
• there is a substantial body of evidence that the
rapid control of asymptomatic hypertension often
results in adverse effects.
• First, assess the accuracy of the blood pressure
reading.
criteria for accuracy, two readings must be taken at
least 5 minutes apart with the patient at rest in a
seated position.
• Avoid measurement error
• consider whether the hypertension is reactive
• determine whether the elevation represents ongoing severe
hypertension or a temporary perturbation.
A study of patients who were hypertensive during an
emergency department visit showed that, at follow-up clinic
visits,
only 69% of those with initial readings of 140 to 159 mm Hg
SBP or 90 to 99 mm Hg DBP remained hypertensive but
100% correlation of subsequent readings in patients who had
>180 mm Hg SBP or >110 mm Hg DBP
• If all of the above criteria are met, the presence of severe
hypertension is confirmed, but the issue of urgency remains.
At this juncture, many patients are referred for urgent
evaluation
Compelling indications for individual drug
classes
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Heart failure
THIAZ, BB, ACEI, ARB, ALDO ANT
Post-myocardial infarction BB, ACEI, ALDO ANT
High CVD risk THIAZ, BB, ACEI, CCB
Diabetes THIAZ, BB, ACEI, ARB, CCB
Chronic kidney disease ACEI, ARB
Recurrent stroke prevention THIAZ, ACEI
• In terms of symptoms, concern arises over patients who
present with nonspecific headache, without other signs of
central nervous system emergency. There are no studies
that document headache alone, which can be mitigated by
immediate treatment, as a risk factor for further
complication.
• In a large study of nonemergent severe hypertension in an
emergency department setting, 269 of 11,531 (2.3%) of
patients had systolic blood pressure >180 mm Hg or
diastolic blood pressure >110 mm Hg.
The most frequent chief complaints were musculoskeletal
pain in 18% and headache in 12%. Only 56 of the 269 were
treated acutely, usually with a calcium channel-blocking
drug.
Appropriate follow up and intervention for asymptomatic
patients without major end-organ damage
Systolic
Diastolic
Follow-up Recommended
<130
<85
Recheck in 2 years
130-139
85-89
Recheck in 1 year
140-159
90-99
Confirm within 2 months
160-179
100-109
Evaluate or refer to a source of care within 1 mo
180-209
110-119
Confirm and treat within 1 wk
210+
120+
Confirm, evaluate, initiate therapy immediately with close follow
Summary
• Patients presenting to the ED with severely increased blood pressure span the
spectrum from hypertensive emergencies requiring immediate intervention
through hypertensive urgencies to uncontrolled hypertension
• Hypertensive emergencies demonstrate rapidly progressive end-organ damage
• Hypertensive urgencies are scenarios in which the blood pressure is severely
increased and there is a history of end-organ disease, signaling an increased risk
of further injury within a short time frame
• The majority of patients presenting to the ED with severely increased blood
pressure have poorly controlled hypertension, are asymptomatic, and simply
need to be referred to a primary care physician
• Treatment strategies should be tailored to the patient's presentation