Hypertensive emergencies: diagnosis and management

Trends in the Incidence of Hypertensive Emergencies in US Emergency Departments From 2006 to 2013

Background

The incidence of hypertensive emergency in US emergency departments (ED) is not well established.

Methods and Results

This study is a descriptive epidemiological analysis of nationally representative ED visit‐level data from the Nationwide Emergency Department Sample for 2006–2013. Nationwide Emergency Department Sample is a publicly available database maintained by the Healthcare Cost and Utilization Project. An ED visit was considered to be a hypertensive emergency if it met all the following criteria: diagnosis of acute hypertension, at least 1 diagnosis indicating acute target organ damage, and qualifying disposition (admission to the hospital, death, or transfer to another facility). The incidence of adult ED visits for acute hypertension increased monotonically in the period from 2006 through 2013, from 170 340 (1820 per million adult ED visits overall) to 496 894 (4610 per million). Hypertensive emergency was rare overall, accounting for 63 406 visits (677 per million adult ED visits overall) in 2006 to 176 769 visits (1670 per million) in 2013. Among adult ED visits that had any diagnosis of hypertension, hypertensive emergency accounted for 3309 per million in 2006 and 6178 per million in 2013.

Conclusions

The estimated number of visits for hypertensive emergency and the rate per million adult ED visits has more than doubled from 2006 to 2013. However, hypertensive emergencies are rare overall, occurring in about 2 in 1000 adult ED visits overall, and 6 in 1000 adult ED visits carrying any diagnosis of hypertension in 2013. This figure is far lower than what has been sometimes cited in previous literature.

Nonmydriatic retinal photography in the evaluation of acute neurologic conditions

Ocular fundus examination is a fundamental component of the neurologic examination. Finding papilledema in headache patients or retinal arterial emboli in stroke patients can be extremely useful. Although examination of the ocular fundus with a direct ophthalmoscope is an important skill for all neurologists, it is rarely and unreliably performed. Nonmydriatic ocular fundus photography, which allows direct visualization of high-quality photographs of the ocular fundus, has been recently proposed for screening neurologic patients in urgent care settings such as emergency departments. This new technology has many potential applications in neurology, including e-transmission of images for remote interpretation.

Clinically presenting acute/subacute ischemic stroke: differential diagnosis of the non-enhanced CT hypodensity by advanced neuroimaging

OBJECTIVES

Patients presenting to the emergency room with an acute or subacute onset of focal neurological deficits are evaluated initially by non-contrast computed tomogram (CT) of the brain. This is primarily carried out to differentiate an ischemic from hemorrhagic stroke. However, other neurological conditions may have a similar clinical presentation as well as only hypodensities on CT scan, thus mimicking ischemic stroke. This review focuses on the advanced neuroimaging modalities that help differentiate these other conditions from a cerebral infarction.

METHODS

The literature was reviewed in order to ascertain what conditions would clinically and by CT mimic an acute/subacute ischemic infarction, and what advanced neuroimaging techniques would be most useful in differentiating these conditions.

RESULTS

Several infectious, inflammatory, metabolic and vascular diseases were found with clinical presentations identical to subacute/acute ischemic cerebral infarction, which also could demonstrate only hypodensities on a non-enhanced CT scan. However, advanced neuroimaging techniques could readily differentiate these conditions from ischemic infarction.

CONCLUSIONS

As presented in this review, although several diseases initially present a diagnostic dilemma upon presentation because of their clinical and non-enhanced CT similarities to cerebral infarction, advanced diagnostic neuroimaging readily establishes their unique pathologies.

Clinical Features in the Management of Selected Hypertensive Emergencies

A hypertensive emergency is a clinical diagnosis that is appropriate when marked hypertension is associated with acute target-organ damage; in this setting, lowering of blood pressure (BP) is typically begun within hours of diagnosis. For hypertensive urgency with no acute target-organ damage, BP lowering may occur over hours to days. A hypertensive emergency may present with cardiac, renal, neurologic, hemorrhagic, or obstetric manifestations, but prompt recognition of the condition and institution of rapidly acting parenteral therapy to lower BP (typically in an intensive care unit) are widely recommended. For aortic dissection, the systolic BP target is lower than 120 mm Hg, to be achieved during the first 20 minutes using a beta-blocker (typically esmolol) and a vasodilator to reduce both shear stress on the aortic tear and the BP, respectively. Otherwise, sodium nitroprusside is the agent with the lowest acquisition cost and longest record of successful use in hypertensive emergencies; however, it is metabolized to toxic thiocyanate and cyanide. Other attractive agents include fenoldopam mesylate, nicardipine, and labetalol; in pregnant women, magnesium and nifedipine are used commonly. Most authors suggest a reduction in mean arterial pressure of approximately 10% during the first hour and a further 10% to 15% during the next 2 to 4 hours; hypoperfusion can result if the BP is lowered too suddenly or too far (eg, into the range of <140/90 mm Hg). Oral antihypertensive therapy can usually be instituted after 6 to 12 hours of parenteral therapy, and the patient moved out of the intensive care unit, when consideration should be given to screening for secondary causes of hypertension. Long-term follow-up to ensure adequate control of hypertension is necessary to prevent further target-organ damage and recurrence of another hypertensive emergency.

Hypertensive encephalopathy

The term hypertensive encephalopathy should be reserved for patients with diffuse cerebral effects of precipitous and sustained rises in blood pressure that reverse when blood pressure is lowered and are not due to infarction or hemorrhage. The definitive diagnosis of this syndrome depends on accurate exclusion of other causes that may be associated with elevated blood pressure and neurologic deficits. Treatment is aimed at preventing or limiting target organ (brain) damage. Therapy should be individualized but centered on reducing the mean arterial blood pressure within a period of minutes to 2 hours, by no more than 20% to 25% or to a diastolic blood pressure of 100 to 110 mm Hg (whichever is higher), using short-acting intravenous agents. Oral or sublingual agents should generally be avoided in hypertensive encephalopathy because they are more likely to cause precipitous falls in blood pressure.