About 30% of American adults have high blood pressure, and millions of people don’t even know it. Asymptomatic hypertension is high blood pressure without any signs or symptoms of target organ damage. Severe hypertension is often defined as 180/120 mm Hg or higher, and any number above that number usually triggers a visit to the emergency department. Many of these patients are referred by a clinic or pharmacy or after using a home blood pressure monitor.
Of course, our job as emergency physicians means we ask the right questions and perform a thorough physical examination to rule out target organ damage. Mild headaches and dizziness do not necessarily mean target organ damage or automatically warrant a workup. Discharge is appropriate without further testing for patients without concerning symptoms or signs. This is supported by several studies and clinical policy. (ACEP. April 2018; https://bit.ly/3ceyAVV.)
Extensive workups, including ECGs, chest X-rays, chemical workups, blood counts, urinalysis, and even troponins, are not needed in most patients. Two prospective observational studies in urban emergency departments found that only five to seven percent of patients had a significant unexpected abnormality on screening tests. No patient presented with a hypertensive emergency. (Ann Emergency Med. 2008;51:231; Am J Urgent Med. 2010;28:235.)
Perhaps most damning was a large retrospective study that measured 58,535 clinic patients referred to the emergency department. These patients all had asymptomatic hypertension (≥ 180/110 mm Hg) and the study found no major adverse events at seven days, eight to 30 days or even six months. Only 2.1% had evidence of target organ damage in their lab results, but investigators did not specify what this entailed. No cranial or thoracic scan was abnormal (0/60). (JAMA Medical Intern. 2016;176:981.)
Several other studies prefer outpatient testing and follow-up over emergency management, and this is the right decision for patients who have a primary care physician for follow-up. It is not unreasonable to initiate antihypertensive therapy in the emergency department based on patient factors and ease of follow-up. This decision, however, should be made on a case-by-case basis and should not use a one-size-fits-all approach.
Lowering blood pressure in the emergency department in people with asymptomatic hypertension does not change the outcome. An excellent retrospective cohort study of 1016 patients found similar revisits and mortality where 435 received antihypertensive treatment for asymptomatic hypertension and the rest were untreated. (Am J Urgent Med. 2015;33:1219.)
Perhaps the most controversial part of this discussion has to do with hypertensive urgency. Frankly, it’s hard to define what hypertensive urgency really is. I frequently ask residents and my colleagues what they consider to be a hypertensive emergency. The long pause followed by a variety of replies and head-scratching tells me no one really knows.
Almost every major journal or textbook defines hypertensive urgency as a marked elevation in blood pressure with no evidence of target organ damage. (StatPearls. Aug. 27, 2021; https://bit.ly/3o6INX3.) UpToDate mentions that asymptomatic hypertension is “sometimes called a hypertensive emergency.” (17 Nov 2021; https://bit.ly/3z9sdw9.) So what is it ? Similar conclusions can be drawn about the hypertensive “urgency” if studies continue to show no major benefit in the treatment and treatment of asymptomatic hypertension.
Either the definition of hypertensive urgency needs to be more specific or disappear altogether. Guidelines do not currently recommend rapidly lowering blood pressure in most patients, even in those with a hypertensive emergency. Only UpToDate suggests that patients with a history of aortic or intracranial aneurysms may need to lower their blood pressure over a period of hours. They don’t provide any policy or research to back up this statement or any details about the required lowering period.
Several studies and task force statements clearly have no proven benefit and may even cause harm if blood pressure reduction is too aggressive. (J Hypertens. 2013;31:1925.) And no clear threshold has delineated which blood pressure is too high and should be lowered. (Association J Am Osteopath. 2013;113:664; https://bit.ly/3cgvO2q.)
Better definition needed
A 2008 study showed that people with hypertensive urgency had a higher risk of later cardiovascular events, but it only defined hypertensive urgency as blood pressure above 220 systolic and/or diastolic above 120 mm Hg.(J Hypertens. 2008;26:657.) Again, what separates these patients from those with a systolic blood pressure of, say, 200 or 210 is simply arbitrary.
Many of our ER patients have high blood pressure. Some have blood pressure ≥180/≥110 mm Hg per day and have no idea. These people are certainly at risk for long-term heart and kidney complications, but our current definitions are insufficient to address the problem. Asymptomatic patients with high blood pressure should not be labeled as a hypertensive emergency.
Instead, focus on what makes the difference. Take a solid history and physical exam, identify those at risk for hypertensive emergencies, and order further studies from there. Arrange for close primary care follow-up and weigh the risks and benefits of prescribing an antihypertensive if the patient is not already taking one for the majority of patients you send home.
Patients whose blood pressure is too high for you to feel comfortable unloading can rest in a quiet, darkened room for 30 minutes with their cell phone on silent to minimize distractions. You will find that this strategy is quite effective in lowering their blood pressure and is backed by research. (J Clin Hypertens [Greenwich]. 2008;10:662; https://bit.ly/3o6XjOQ.)
We should demand a more detailed definition of the hypertensive emergency to reduce crowding in our waiting rooms, decrease confusion, and provide safe and optimal blood pressure reduction for our patients. Call it what it is: The hypertensive emergency is not immediately urgent.
Dr. Briggsis an assistant professor of emergency medicine at the University of South Alabama in Mobile. He is the founder, podcast co-host and editor of EM Board Bombs (https://www.emboardbombs.com), a cross-platform educational tool designed to prepare for counseling and focus on what you need to know to practice emergency medicine. Follow him on Twitter@blakebriggsmd.