National guidelines in recent years have emphasized the need to control blood pressure systematically over time to reduce the risk of target organ damage, morbidity, and mortality.1,2 Guidelines of the American College of Emergency Physicians for the management of asymptomatic elevated blood pressure in the emergency department continue to recommend caution regarding rapid reduction of blood pressure in people without symptoms or evidence of hypertensive crisis because of its potential to do harm.3 Rapid drops in blood pressure can cause hypoperfusion to the brain or heart which can be life-threatening.4–6
Blood pressure that is 180/120 mm Hg or higher is considered a hypertensive crisis.1,7 Less than 2% of people with hypertension are expected to have a hypertensive crisis.8 If there is evidence of end-organ damage, the crisis is considered emergent; otherwise the crisis is urgent and can be managed more slowly. Rapid reduction of blood pressure can be dangerous and should only be done under specific clinical situations.
In a large multicenter study, 1,546 patients were admitted to hospital emergency departments with hypertensive crisis, 391 (25.3 %) of which were determined to be emergent.9 Specific end-organ damage that was identified included: pulmonary edema (30.9%), stroke (22%), myocardial infarction (17.9%), aortic dissection (7.9%), renal failure (5.9%), and hypertensive encephalopathy (4.9%). Most (55.6%) of the hypertensive crisis patients reported non-specific symptoms like headache or palpitations. Only 28.3% reported heart-related symptoms like shortness of breath, chest pain, or syncope.
Medication choices for hypertensive emergencies depend to some degree on the end-organ damage that has or is occurring, other co-morbidities, and risk factors that may be present.7,10
Studies of patients in the immediate period after a cerebrovascular event or intracranial hemorrhage have looked at the impact of rapid or intensive lowering of blood pressure.11–13 Lattanzi et al. analyzed the outcomes in five clinical trials (total n=350) that compared intensive blood pressure lowering with standard treatment immediately after a stroke.12 The intensive treatment was found to be more effective against the expansion of hematomas after stroke, a positive outcome, but there was no significant reduction in death or disability three months later. There was no significant difference in the rates of early neurological deficit (risk ratio [RR] 1.03 [0.88 – 1.20], p=0.703) or severe hypotension (RR 0.84 [0.37 – 1.94], p=0.689) within the first three days post-stroke. Additionally, there was no significant difference in the recurrence of stroke (RR 0.95 [0.46 – 1.96], p=0.887), acute coronary events (RR 1.13 [0.45 – 2.85], p=0.795), or serious treatment-related adverse events within three months (RR 1.05 [0.94 – 1.17], p=0.404). There was however a higher rate of renal failure among those patients who had undergone intensive treatment (RR 2.18 [1.08 – 4.41], p=0.031).
Qureshi et al. also compared outcomes among 1,000 patients with acute cerebral hemorrhage, half of whom were randomly assigned a more intensive blood-pressure lowering treatment.13 While intensive treatment did not result in a significant difference in post-stroke death or disability, the rate of renal adverse events within a week of the randomization was significantly higher in the intensive treatment group (9% versus 4%, p=0.002).
- Chobanian A V., Bakris GL, Black HR, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003; 42 (6): 1206-1252.
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPMACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension 2018; 71 (19): e127-e248.
- Wolf SJ, Lo B, Shih RD, Smith MD, Fesmire FM. Clinical policy: Critical issues in the evaluation and management of adult patients in the emergency department with asymptomatic elevated blood pressure. Ann Emerg Med 2013; 62 (1): 59-68.
- O’Mailia J, Sander G, Giles T. Nifedipine-associated myocardial ischemia or infarction in the treatment of hypertensive urgencies. Ann Intern Med 1987; 107 (2): 185-186.
- Miller JB, Calo S, Reed B, et al. Cerebrovascular risks with rapid blood pressure lowering in the absence of hypertensive emergency. Am J Emerg Med August 2018.
- Shayne PH, Pitts SR. Severely increased blood pressure in the emergency department. Ann Emerg Med 2003; 41 (4): 513-529.
- Adebayo O, Rogers RL. Hypertensive emergencies in the emergency department. Emerg Med Clin N Am 2018; 33 (3): 539-551.
- Varounis C, Katsi V, Nihoyannopoulos P et al. Cardiovascular hypertensive crisis : recent evidence and review of the literature. 2017; 3 (January): 1-5.
- Pinna G, Pascale C, Fornengo P, et al. Hospital admissions for hypertensive crisis in the emergency departments: a large multicenter Italian study. PLoS One 2014; 9 (4): e93542.
- Ipek E, Afs A. Hypertensive crisis : an update on clinical approach and management. Curr Opin Cardiol; 2017: 397-406.
- Anderson CS, Heeley E, Huang Y, et al. Rapid blood-pressure lowering in patients with acute intracerebral hemorrhage. N Engl J Med 2013; 368 (25): 2355-2365.
- Lattanzi S, Cagnetti C, Provinciali L, Silvestrini M. How should we lower blood pressure after cerebral hemorrhage? A systematic review and meta-analysis. Cerebrovasc Dis 2017; 43 (5-6): 207-213.
- Qureshi A, Palesch Y, Barsan W et al. Intensive blood-pressure lowering in patients with acute cerebral hemorrhage. N Engl J Med 2016; 375 (11): 1033-1043.