Acute Management of Severe Asymptomatic Hypertension

IN THIS ARTICLE

• Patient history; what to ask
• Cardiovascular risk factors
• Disposition pathway
• Oral medications

Approximately one in three US adults, or about 75 million people, have high blood pressure (BP), which has been defined as a BP of 140/90 mm Hg or higher.¹ Unfortunately, only about half (54%) of those affected have their condition under optimal control.¹ From an epidemiologic standpoint, hypertension has the distinction of being the most common chronic condition in the US, affecting about 54% of persons ages 55 to 64 and about 73% of those 75 and older.^2,3 It is the number one reason patients schedule office visits with physicians; it accounts for the most prescriptions; and it is a major risk factor for heart disease and stroke, as well as a significant contributor to mortality throughout the world.⁴

HYPERTENSIVE URGENCY VS EMERGENCY

Hypertensive urgencies and emergencies account for approximately 27% of all medical emergencies and 2% to 3% of all annual visits to the emergency department (ED).⁵ Hypertensive urgency, or severe asymptomatic hypertension, is a common complaint in urgent care clinics and primary care offices as well. It is often defined as a systolic BP (SBP) of ≥ 160 mm Hg and/or a diastolic BP (DBP) ≥ 100 mm Hg with no associated end-organ damage.^5-7 Patients may experience hypertensive urgency if they have been noncompliant with their antihypertensive drug regimen; present with pain; have white-coat hypertension or anxiety; or use recreational drugs (eg, sympathomimetics).^5,8-10

Alternatively, hypertensive emergency, also known as hypertensive crisis, is generally defined as elevated BP > 180/120 mm Hg. Equally important, it is associated with signs, symptoms, or laboratory values indicative of target end-organ damage, such as cerebrovascular accident, myocardial infarction (MI), aortic dissection, acute left ventricular failure, acute pulmonary edema, acute renal failure, acute mental status changes (hypertensive encephalopathy), and eclampsia.^5,7,8,11,12

Determining appropriate management for patients with hypertensive urgency is controversial among clinicians. Practice patterns range from full screening and “rule-outs”—with prompt initiation of antihypertensive agents, regardless of whether the patient is symptomatic—to sending the patient home with minimal screening, laboratory testing, or treatment.

This article offers a guided approach to managing patients with hypertensive urgency in a logical fashion, based on risk stratification, thereby avoiding both extremes (extensive unnecessary workup or discharge without workup resulting in adverse outcomes). It is vital to differentiate between patients with hypertensive emergency, in which BP should be lowered in minutes, and patients with hypertensive urgency, in which BP can be lowered more slowly.¹²

PATHOPHYSIOLOGY

Normally, when BP increases, blood vessel diameter changes in response; this autoregulation serves to limit damage. However, when BP increases abruptly, the body’s ability to hemodynamically calibrate to such a rapid change is impeded, thus allowing for potential end-organ damage.^5,12 The increased vascular resistance observed in many patients with hypertension appears to be an autoregulatory process that helps to maintain a normal or viable level of tissue blood flow and organ perfusion despite the increased BP, rather than a primary cause of the hypertension.¹³

The exact physiology of hypertensive urgencies is not clearly understood, because of the multifactorial nature of the process. One leading theory is that circulating humoral vasoconstrictors cause an abrupt increase in systemic vascular resistance, which in turn causes mechanical shear stress to the endothelial wall. This endothelial damage promotes more vasoconstriction, platelet aggregation, and activation of the renin-angiotensin-aldosterone system, which thereby increases release of angiotensin II and various cytokines.¹⁴

HISTORY AND PHYSICAL

A detailed medical history is of utmost importance in distinguishing patients who present with asymptomatic hypertensive urgency from those experiencing a hypertensive emergency. In addition, obtain a full medication list, including any nutritional supplements or illicit drugs the patient may be taking. Question the patient regarding medication adherence; some may not be taking antihypertensive agents as prescribed or may have altered the dosing frequency in an effort to extend the duration of their prescription.^5,8 Table 1 lists pertinent questions to ask at presentation; the answers will dictate who needs further workup and possible admission as well as who will require screening for end-organ damage.⁷

The physical exam should focus primarily on a thorough cardiopulmonary and neurologic examination, as well as funduscopic examination, if needed. A complete set of vital signs should be recorded upon the patient’s arrival to the ED or clinic and should be repeated on the opposite arm for verification. Beginning with the eyes, conduct a thorough funduscopic examination to evaluate for papilledema or hemorrhages.⁵ During the cardiopulmonary exam, attention should be focused on signs of congestive heart failure and/or pulmonary edema, such as increased jugular vein distension, an S3 gallop, peripheral edema, and pulmonary rales. The neurologic exam is essential in evaluating for cerebrovascular accident, transient ischemic attack, or intracranial hemorrhage. A full cranial nerve examination is necessary, in addition to motor and sensory testing, at minimum.^5,9