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

• 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 Diastolic Category

JNC VI

<120 <80 Optimal

<130 <85 Normal

130-139 85-89 High normal

140-159 90-99 Stage 1 (mild)

160-179 100-109 Stage 2 (moderate)

≥180 >110 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 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 12.0• Aortic dissection 2.0• Eclampasia 2.0

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 peri-operative hypertension and the hypertensive pregnant patient without proteinuria or signs of pre-eclampsia

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 follow-up

• 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 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.

• 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 3-rapid 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.

• 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

• 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