Hypertensive crisis is a widespread health problem since the prevalence of hypertension in adult patients is increasing over time. The high percentage of patients with hypertension that have poor control over their conditions makes the hypertensive crisis a possible scenario for many cases.
A hypertensive crisis could be further distinguished into two groups: hypertensive urgency, or hypertensive emergency, differentiating the latter as the presence of target organ damage, usually to the kidneys, brain, heart, lungs, and retina.
Diagnosis and management rely on assessing for target organ damage and appropriate treatment of blood pressure measurements and the underlying medical condition.
Introduction to Hypertensive Crisis
A hypertensive crisis is a common presentation in emergency departments. They represent two different clinical scenarios in which the management strategies differ, and so do the diagnostic measures. Understanding the outcomes and the morbidity and mortality each syndrome pose on patients is of paramount relevance to practicing physicians since overlooking the clinical situation could lead to disastrous outcomes.
Over the last few years, several guidelines recommended in favor of the correct classification and stratification of patients having severely elevated blood pressures based on the diagnostic and management strategies, as well as the outcomes of each of the different presentations.
This article will discuss the classification of hypertensive crisis, briefly describe the pathophysiological implications in the different presentations, present the diagnostic strategies for patients with hypertensive crisis, and outline the essential management points of the conditions.
Hypertensive crisis is a term coined in 1974 and refers to severely elevated blood pressure (1). It denotes an elevation of 180 mmHg of systolic blood pressure and 120 mmHg of diastolic blood pressure (1-4).
The term differentiates into two different clinical entities according to the presence or not of evidence of end-organ damage into: (2-4)
- Hypertensive urgency: a severely elevated blood pressure that is usually oligo- or asymptomatic.
Note: current guidelines and several authors are not considering this clinical entity since management strategies in the acute presentation do not differ from those of long-term follow-up in patients with severely elevated blood pressure (5-7).
- Hypertensive emergency: a patient with severely elevated blood pressure in the context of acute end-organ damage, producing signs and symptoms of the implicated systems. These include cardiovascular (acute myocardial ischemia, aortic dissection), cerebrovascular (hypertensive encephalopathy, ischemic/hemorrhagic stroke), renal (acute or chronic renal failure), and hematologic (microangiopathic anemia) conditions (1-7).
High blood pressure is one of the most common conditions. In the U.S., around 116 million people suffer from the disease. From this highly majoritarian number, a %79 of people are estimated to not have their condition under appropriate control. (8)
Uncontrolled hypertension is one of the factors implicated in the production of hypertensive crisis. Indeed, a not negligible number of patients presenting with hypertensive emergencies were not aware of their condition, producing devastating consequences for the person’s life, including increased morbidity, mortality, and decreased quality of life.
According to a systematic review and meta-analysis of the literature performed by Astarita et al., hypertensive crises represent a low prevalence with respect to acute consultations, accounting for 0.3% for emergencies and 0.9% for urgencies. In the same study, the authors found that the most prevalent cause of acute end-organ damage among emergencies was pulmonary edema secondary to heart failure (32%). The list continued with ischemic stroke, complicated aortic aneurysm, and hypertensive encephalopathy. (9)
Etiology of hypertensive crisis
Hypertensive crisis may present de novo in undiagnosed patients. In cases in which a previous diagnosis is present, medication noncompliance is a possible cause. Further, there are secondary causes of hypertensive crises: (10, 11)
- Medication noncompliance in patients with essential hypertension.
- Medications: NSAIDs and acetaminophen, corticosteroids, venlafaxine, anti-VEGF drugs, sympathomimetics, erythropoietin, cyclosporine, MAOI interactions, caffeine, among others.
- Illicit drugs: cocaine, phencyclidine, and amphetamines.
- Renal causes: glomerulonephritis, renal artery disease, renal cell carcinoma, tubulointerstitial disease, obstructive urinary disease.
- Endocrine causes: Cushing’s syndrome, primary hyperaldosteronism, renin-secreting tumors, hyperthyroidism.
- Neurological causes: traumatic brain injury, hemorrhagic stroke, cerebral infarction, spinal cord injury, and brain tumor.
- Cardiovascular: coarctation of the aorta.
- Pregnancy-related causes: eclampsia, pre-eclampsia.
- Pain-related: trauma, painful syndromes, such as headache syndromes or neuropathies.
- Psychiatric or psychological conditions: anxiety, panic disorders.
Risk factors promoting hypertensive crisis
There have been proposed several risk factors for the production of hypertensive crisis: (12)
- Female sex.
- Overweight, obesity.
- A higher number of antihypertensive drugs.
- Somatoform disorder.
- Medication nonadherence.
Approach to the patient with hypertensive crisis
Patients presenting to the acute setting with severely elevated blood pressure should be promptly evaluated. The first step in the approach is to follow the ABCDE survey approach.
A focused clinical history should point to signs and symptoms of acute end-organ damage, as well as exacerbating factors such as drugs, pain, emotional states, clinical comorbidities, or intoxications, among others (see etiology).
Measure arterial pressure in both arms. When thinking about arterial dissections, it is useful to look for unequal measurements in different limbs. For example, aortic dissection will present with different measurements in upper limbs to lower limbs; subclavian dissections, unequal blood pressure in limbs; etc. (2)
Patients who present with a hypertensive emergency usually complain of symptoms that represent acute damage to the target organ: (2, 3, 5, 13)
- Pulmonary edema secondary to heart failure: left ventricular overload due to increased blood pressure, usually in the context of chronic heart failure, could produce volume overload to the pulmonary circulation. Consequently, patients complain of severe dyspnea of rapid progression and orthopnea, and may show signs of hypoxemia.
- Myocardial ischemia: pressure overload in the myocardial wall increases the demand for oxygen consumption in the myocardiocytes. Atherosclerotic disease impedes normal blood flow to myocardial cells, inducing a state of decreased perfusion in high-need states. Decreased oxygen consumption in the aforementioned cells leads to a cascade of biochemical events involved in apoptosis, necrosis, and the production of clinical symptoms. Chest pain, dyspnea, signs of acute heart failure (volume overload), and sympathetic systemic response (pallor, sweating, dizziness) may represent the cardinal symptoms in this set of patients.
- New focal neurological signs and symptoms could be the expression of stroke, including ischemic or hemorrhagic in nature. Cardioembolic events, in-situ atherosclerosis, or microaneurysm rupture are some of the leading causes of these clinical entities. The presentation will depend on the affected arterial territory or brain parenchyma.
- Acute renal failure might be the cause or a consequence of severely elevated hypertension. Patients might present with signs and symptoms of renal dysfunction, such as oliguria, anuria, and hyper azotemia, as well as syndromes related to glomerular, interstitial, or urinary tract conditions.
- Retinal manifestations should be included in the workup investigations for end-organ damage.
Patients presenting with severely elevated blood pressure and no signs and symptoms of end-organ damage (hypertensive urgency) may complain of unspecific symptoms, such as low-grade headaches, dizziness, epistaxis, and anxiety, or no symptoms at all. (7, 13)
Patients with evidence of acute end-organ damage should promptly receive targeted treatment to lower blood pressure levels. ICU management with intravenous antihypertensive medication, monitorization, and treatment of the concomitant condition are warranted.
Subjects with asymptomatic severely elevated blood pressure, might benefit from observation, and control of hypertension over 24-48hs with institution, reinstitution, or modification of oral antihypertensive treatment. In special cases, patients with a high cardiovascular risk, and those in which continuous follow-up is uncertain, may benefit from inpatient observation.
The latest guidelines on the management of asymptomatic severely elevated blood pressure do not recommend routine diagnostic workups. However, patients with atypical or unspecific symptoms such as dizziness, headaches, or epigastric pain may benefit from further evaluation, especially if they present with cardiovascular risk factors.
For hypertensive emergencies, a diagnostic workup is guided by the suspected condition.
General diagnostic measures include: (2, 10)
- Full blood count: useful in detecting microangiopathic anemia, especially a peripheral blood smear looking for schistocytes.
- Basic metabolic panel: urea and creatinine might be elevated in acute or chronic kidney conditions.
- Acid-base and gases: different disturbances may point to the degree of decompensation of renal or respiratory causes.
- Urinalysis: relevant in the detection of hematuria, renal causes of hypertension, as well as urinary casts.
- Cardiac troponin: a marker of cardiac ischemia.
- Chest x-ray: might show cardiomegaly; widened mediastinum, as in thoracic aortic aneurysm; alveolar perihilar infiltrates, Kerley lines, interstitial lines, as in pulmonary edema.
- ECG: might show chronic changes due to long-standing hypertension, such as, left ventricular hypertrophy, or acute manifestations as in cardiac ischemia.
- Head CT/MRI: the sequence of choice for the diagnosis of cerebral infarctions. Non-contrast enhanced head C.T. is the first-line diagnostic tool for hemorrhagic stroke.
Management of Hypertensive Crisis
Hypertensive urgency or asymptomatic severely elevated hypertension might not always require acute treatment, but rather physicians should be focused on education for adherence to long-term management. (2, 5, 14)
On the other hand, hypertensive emergencies require prompt treatment in the ICU setting. This section offers an outlined version of the treatment recommendations extracted from the 2017 ACC/AHA Clinical Practice guidelines (5).
- Blood pressure goals: in severe pre-eclampsia or eclampsia and pheochromocytoma, blood pressure should be lowered to <140 systolic blood pressure in an hour. If aortic aneurism is detected, the blood pressure goal is <120mmHg SBP. Other causes of hypertensive emergency require a decrease of 20-25% in the next hour, followed by a reduction to 160100-110 mmHg in the next 2-6 hours and to normal levels in 24-48 hours.
Conditions and first-line drugs: a complete approach will be offered in future articles.
- Aortic dissection: esmolol and labetalol. Then vasodilator such as nicardipine or nitroprusside.
- Acute pulmonary edema: clevidipine, nitroprusside, nitroglycerin.
- Acute coronary syndrome: esmolol, labetalol, nicardipine nitroglycerin.
- Acute renal failure: fenoldopam, clevidipine.
- Perioperative hypertension: (>20% of preoperative levels for more than 15 minutes) clevidipine, esmolol, nicardipine, and nitroglycerin.
- Eclampsia or pre-eclampsia: hydralazine, labetalol, nicardipine.
The prompt recognition of patients with acute end-organ damage is the most important step in the assessment of a patient presenting with a hypertensive crisis. Immediate intravenous antihypertensive agents, according to the underlying condition, are warranted, along with ICU or coronary unit admission. This has been shown to improve outcomes in this group of patients.
In patients with no signs or symptoms of hypertensive emergency, acute management consists of observation and reinforcement of long-term follow-up strategies. Prompt cardiology consultation and 24-48 hours follow-up are reasonable for asymptomatic patients.
The author does not report any conflict of interest.
This information is for educational purposes and is not intended to treat disease or supplant professional medical judgment. Physicians should follow local policy regarding the diagnosis and management of medical conditions.
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Franco Cuevas is a physician who graduated from the National University of Córdoba, Argentina. He practices general medicine in the Emergency Department at Sanatorio de la Cañada, Córdoba. His focus is on writing medical content to improve physicians' access to relevant medical information for daily practice. He has participated in some research projects and has a special joy in teaching and writing about medical concepts.