Hypertensive emergencies are generally defined as severely high blood pressure—180/110-120 mm Hg or higher—with signs of acute target organ damage. Such patients are symptomatic, with nausea, vomiting, headache, dizziness, altered mental status, or evidence of acute injury to the heart, brain, or kidneys, and occasionally with acute changes on a head CT scan.
There is no disagreement in the medical literature that these patients should be treated immediately in the ED, primarily with intravenous antihypertensives, to decrease the blood pressure by 20-25 percent in the first hour and to about 160/110 mm Hg within six hours. At that point, start oral agents so that intravenous medications can be tapered. Patients can be discharged when they are asymptomatic and off IV medications for about 24 hours.
A less severe version of acute hypertension is hypertensive urgency, defined as high blood pressure without symptoms or target organ damage. These patients may have some hypertension-related symptoms, such as headache, dizziness, or even chest pain. It's generally agreed that those with symptoms should be treated in the ED, but a patient with a similar elevation in blood pressure but no symptoms is the more common scenario.
Two frequently quoted articles concluded that asymptomatic patients with hypertensive urgency do not require acute treatment or admission to the hospital. Even though the blood pressure is very high, it is generally suggested that such patients can be discharged, treated with oral antihypertensives, and referred for follow-up within seven days.
Characteristics and Outcomes of Patients Presenting with Hypertensive Urgency in the Office Setting
Patel KK, Young L, et al.
JAMA Intern Med.
This widely quoted article retrospectively analyzed data over six years, and reviewed the characteristics and short-term outcomes of more than 58,000 patients presenting with hypertensive urgency to 100 outpatient practices within the Cleveland Clinic Healthcare System. There was a documented history of hypertension in 73 percent of patients, and 58 percent had been taking two or more antihypertensive medications.
Hypertensive urgency was defined as a systolic blood pressure higher than 180 mm Hg or a diastolic pressure higher than 110 mm Hg. The aim was to determine whether ED referral or admission to the hospital would be associated with a better outcome than being discharged home with oral medications. The hypothesis was that asymptomatic ambulatory patients with hypertensive urgency would have a low rate of cardiovascular events in the short term, and referral to the hospital would not improve outcome. Only 426 (0.7%) of the 58,109 patients were referred to the hospital for blood pressure management. They generally had a higher blood pressure, with a systolic pressure of at least 200 mm Hg.
Two percent of the patients sent to the hospital had evidence of target organ injury, but testing was generally unrevealing: Only 5.5 percent of tests were abnormal. Curiously, 38 percent of patients sent to the ED received no acute intervention for hypertension. About 60 percent received a one-time dose of an antihypertensive medication, and about 80 percent of the ED patients were sent home. The mean blood pressure at ED discharge was 160/87 mm Hg. The cause of hypertension was nonadherence to therapy in 25 percent and unknown in 60 percent. Most of the patients had uncontrolled hypertension six months after the ED visit.
Such lack of testing and ED treatment for a patient with severe hypertension who was transferred to the ED from an office is confusing. The 2017 American College of Cardiology and the American Heart Association guidelines do not include blood pressure goals for asymptomatic severely hypertensive patients, and caution against aggressively lowering blood pressure.
These authors concluded that their study and other studies indicated that hypertensive urgency does not portend an acute risk. The occurrence of an adverse cardiovascular event in asymptomatic patients in this study was less than one percent in six months despite continued poor blood pressure control. Importantly, about 20 percent of these patients never had another visit to the health care system within six months, so their outcome is unknown. The authors said the relatively common hypertensive urgency is a condition that can be safely treated in the outpatient setting and that adverse cardiovascular complications are rare in the short term. An editorial accompanying the study questioned the usefulness of even having a diagnosis termed “hypertensive urgency.” (JAMA Intern Med. 2016;176:988; http://bit.ly/2IzKJTh.)
Comment: The prevalence of hypertensive urgency in the outpatient setting is largely unknown, and its management lacks observational studies or randomized clinical trials. There are essentially three options when patients present to the office or clinic with severely elevated blood pressure: They can be sent home after treatment or with adjustments to their antihypertensive therapy, be directly admitted to the hospital, or sent to the ED. The overall rate of a major adverse cardiovascular event at six months was less than one percent in both groups, with 496 patients experiencing acute coronary syndrome or a stroke or TIA. Regardless of where the patients were treated, the percentage with controlled hypertension at six months was poor.
Fewer than one of 100 asymptomatic patients was referred to the hospital or ED for management. Referral to the hospital, although associated with increased inpatient hospitalization and significant cost, did not result in a better outcome. The authors said they were disappointed that most patients with hypertensive urgency still had uncontrolled hypertension six months later.
This study seems to indicate that hypertensive urgency may simply be an illusion and no more serious than a single isolated high blood pressure reading. These office clinicians did not seem impressed by a very high blood pressure in an asymptomatic patient. Emergency clinicians seem, however, to be more impressed. Nonetheless, many individuals with hypertensive urgencies are admitted to the hospital, treated with powerful medications, and undergo numerous tests. Individuals can experience adverse effects from medications.
Eight patients (2%) sent to the ED had evidence of target organ damage, including pulmonary edema, acute kidney injury, and elevated cardiac biomarkers. The significance of elevated cardiac enzymes is unclear, and there is no evidence that this test should be ordered. Only 60 percent of the patients received medications in the ED for their hypertension, usually a one-time dose of an antihypertensive medication. About 40 percent received no treatment in the ED.
It also appears that few patients sent to the ED had any sort of evaluation or testing. About 12 percent had a head CT, 35 percent had a chest x-ray, but only three of 387 patients had an ECG. Such lack of testing in patients with severe hypertension transferred from an office is confusing. A blood pressure medication was prescribed in 26 percent of those discharged, the prior blood pressure medication dose was increased in seven percent, but 82 percent had no change in their prior blood pressure medication. Overall, this study seems to contradict all the hoopla concerning the need to treat even severely high asymptomatic hypertension quickly and aggressively.
Blood Pressure Treatment and Outcomes in Hypertensive Patients without Acute Target Organ Damage: A Retrospective Cohort
Levy PD, Mahn JJ, et al.
Am J Emerg Med.
The study evaluated the effects of hypertension therapy in the ED in patients with a markedly elevated blood pressure but no signs or symptoms of acute target organ damage. It included 1000 patients with a blood pressure higher than 180/110 mm Hg and no acute symptoms. The authors noted a divergent practice for clinicians who are confronted with patients with a markedly elevated blood pressure but no symptoms of target organ damage.
This study included patients from approximately 12 large or university medical centers. Patients were separated into two groups: those who received ED treatment and those who did not. Less than half (43%) received ED treatment for their elevated blood pressure, most often (88%) with oral clonidine. About half also received an oral dose of their baseline medication. Those treated were more likely to have a higher blood pressure and headache on arrival.
The rate of ED returns between the two groups was similar, approximately four percent. The overall mortality at 30 days was 0.2 percent in both groups. The authors concluded that blood pressure reduction for patients with acute hypertension without target organ damage provided no direct benefit. The death rate of those discharged was also low. They concluded that data support the lack of specific benefit for immediately lowering markedly elevated blood pressure in the ED in the absence of acute hypertensive target organ damage. In fact, these patients were thought to represent only a pseudohypertensive emergency.
The authors considered clonidine the ideal agent for treating high blood pressure in the ED. Clonidine is preferred because it is inexpensive, effective, easy to administer, and has a quick onset; it is not usually prescribed for outpatients. Like other authors, they cautioned against using sublingual nifedipine, a rather old recommendation. They also said initiating proper outpatient antihypertensive therapy is of the utmost importance, either by an emergency physician or an outpatient clinician.
Complications related to hypertension were infrequent, and the all-cause mortality rate was low. Every 20 mm Hg systolic increase and 10 mm Hg diastolic increase are associated with double vascular mortality for uncontrolled hypertension long-term.
Comment: Similar to the first study examined here, there was no short-term benefit of immediate treatment of markedly elevated blood pressure in the ED, and the short-term outcome for these patients seems to be rather benign. Seventy percent of these patients, however, received a prescription for an antihypertensive medication by the emergency physician at discharge. I think 100 percent should have received one. Note that the new goal in treating hypertension is actually 130/80 mm Hg. I am a strong advocate for providing a prescription for a hypertensive medication at discharge. I also give a few of the prescribed medication to be taken at home until the script is filled. It's prudent to start with a low dose and to do your best to arrange follow-up.
Many patients will probably conclude that their hypertension is not a big deal if they are not treated in the ED or are not given a script. Even though you told them they could have a stroke or an MI because of the hypertension, it seems logical that they will assume their asymptomatic hypertension is fine because you did not immediately treat it or prescribe a medication. I would not discharge a patient whose blood pressure was still 180/110 mm Hg; I would treat in the ED. Even though only one in 100 patients had an adverse outcome, you can expect to spend your vacation at a malpractice trial if a hypertensive patient has an MI or a stroke soon after you saw them and didn't intervene in the ED.
Initial Antihypertensive Medication (Monotherapy) that Can Be Prescribed by Emergency Physicians
- Thiazide-type diuretics, especially chlorthalidone
- Angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs)
- Calcium channel blockers (dihydropyridine type)
Notes: At the same level of blood pressure control, most antihypertensive drugs provide the same degree of cardiovascular protection. Initially prescribe a low dose of an extended-release medication so it can be taken once a day.
The best single-drug therapy for essential hypertension in black patients are diltiazem and a thiazide diuretic. ACE inhibitors and beta blockers are not as effective.
A thiazide diuretic in white patients can be used, but also consider ACE inhibitors, calcium channel blockers, or ARBs. Beta blockers are not commonly used in the absence of a specific indication.
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Dr. Robertsis a professor of emergency medicine and toxicology at the Drexel University College of Medicine in Philadelphia. Read the Procedural Pause, a blog by Dr. Roberts and his daughter, Martha Roberts, ACNP, PNP, athttp://bit.ly/EMN-ProceduralPause, and read his past columns athttp://bit.ly/EMN-InFocus.