Approach to hypertensive emergencies and urgencies in children

INTRODUCTION — This topic addresses the diagnostic approach to hypertensive emergencies and urgencies in children. The treatment of pediatric hypertensive emergencies is discussed separately. (See "Initial management of hypertensive emergencies and urgencies in children".)

BACKGROUND — Hypertension is relatively common in the pediatric population and is frequently undiagnosed. By contrast, first-episode hypertensive emergencies in children are rare, occurring in approximately 2 per 10,000 emergency department visits in one observational study [1]. (See "Epidemiology, risk factors, and etiology of hypertension in children and adolescents", section on 'Epidemiology'.)

DEFINITION — Proper management of children with elevated blood pressure (BP) requires working knowledge of pediatric BP standards and a clear understanding of when elevated BP requires emergency, urgent, or routine care.

Blood pressure classification — In the United States, the definition of childhood hypertension is statistically based upon the normative distribution of BP obtained from approximately 50,000 normal-weight children and is stratified by sex, age, and height (figure 1A-B and table 1 and table 2). (See "Definition and diagnosis of hypertension in children and adolescents", section on 'Definitions'.)

The 2017 the American Academy of Pediatrics (AAP) Clinical Practice Guideline for high BP in children and adolescents classifies BP based on normative values in children younger than 13 years of age and on fixed thresholds for children 13 years of age and older (table 3) [2]. The BP categories include:

●Normal BP

●Elevated BP

●Stage 1 hypertension

●Stage 2 hypertension

Hypertension — Hypertension in children <13 years of age is defined as systolic and/or diastolic BP ≥95^th percentile, and for adolescents (≥13 years of age), BP values greater than 130/80 measured upon three or more occasions [2]. Hypertension in children is further divided into two stages (table 3):

●Stage 1 hypertension – For children with stage 1 hypertension, more time is allowed for evaluation and initial treatment with nonpharmacologic therapy unless the patient is symptomatic or has hypertensive target-organ damage. (See "Nonemergent treatment of hypertension in children and adolescents".)

BP definitions of stage 1 hypertension in children are:

•Children 1 to <13 years of age with BP readings ≥95^th percentile to <95^th percentile+12mmHg

•Children aged ≥13 years with BP readings between 130/80 to 139/89

●Stage 2 hypertension – Children with stage 2 hypertension have the most severe degree of hypertension and may require urgent (asymptomatic or minor symptoms) or emergency (serious symptoms or evidence of target-organ damage) treatment. (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Initial management'.)

BP definitions of stage 2 hypertension in children are:

•Children 1 to <13 years of age with BP readings ≥95^th percentile+12mmHg

•Children aged ≥13 years with BP ≥140/90

Recognition of hypertension in neonates and infants also depends upon comparison with normative values. However, these BP measurements are adjusted for differing parameters than in children over one year of age: birth weight and postconceptual age for neonates (table 4); age and, to a limited extent, weight and length for the perinatal period up to one year of age (figure 1A-B). (See "Evaluation and diagnosis of hypertension in infants between one month and one year of age", section on 'Normal blood pressure' and "Etiology, clinical features, and diagnosis of neonatal hypertension", section on 'Normal blood pressure'.)

Hypertensive emergency — Severe hypertension, or hypertensive crisis, has traditionally been divided into hypertensive emergency and hypertensive urgency. However, any classification scheme that divides the clinical presentation of acute severe hypertension into separate categories is by nature arbitrary [3,4]. Clinical judgment must be used to gauge the severity of hypertension and its potential for life-threatening end-organ damage that determines the timing and intensity of management. As noted by the 2017 AAP guidelines, pediatric patients should be referred to an immediate source of care (eg, emergency department) if they have serious symptoms and the BP value is at the stage 2 level (table 3), or the BP is >30 mm Hg above the 95th percentile for children less than 13 years of age or >180/120 in an adolescent (table 1 and table 2) [2]. In the clinical setting of a hypertensive emergency, there is concern for acute hypertensive end-organ damage that can be life-threatening.

However, it is important to note that the absolute degree of BP elevation is less important than whether end-organ symptoms and/or damage are present and associated with an acute change in mean arterial pressure. For example, a child with chronic hypertension may have very high BP measurements with no symptoms. Another child with an acute rise in BP may manifest a hypertensive emergency despite a BP that is only moderately elevated. The importance of both BP height and rate of change in predisposing to hypertensive emergencies in children is highlighted by a retrospective case-control study that showed both a higher peak and more rapid rate of rise of BP among 35 children diagnosed with reversible posterior leukoencephalopathy syndrome (RPLS) compared with 14 controls with other similar clinical characteristics [5].

Hypertensive emergencies in children most commonly manifest as hypertensive encephalopathy: severe BP elevation with cerebral edema and neurological symptoms of lethargy, coma, and/or seizures [6,7]. This pathology is caused by cerebrovascular endothelium breakdown secondary to failure of cerebral autoregulation. (See "Moderate to severe hypertensive retinopathy and hypertensive encephalopathy in adults", section on 'Mechanisms of vascular injury'.)

Other sites for target-organ damage include: eyes (papilledema, retinal hemorrhages, and exudates), heart (heart failure), and kidneys (renal insufficiency). Patients with a hypertensive emergency warrant prompt administration of intravenous (IV) antihypertensive agents to rapidly lower BP (algorithm 1). (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Hypertensive emergency' and "Initial management of hypertensive emergencies and urgencies in children", section on 'Initial treatment'.)

Hypertensive urgency — A severe elevation in BP without symptoms or evidence of acute target-organ damage describes a hypertensive urgency. A child with hypertensive urgency warrants an immediate evaluation. When the urgency arises from an acute process with a rapid change in mean arterial pressure, intervention should occur promptly, and treatment with IV antihypertensive medications is appropriate (table 5). However, in the setting of a chronic condition (eg, chronic kidney disease) where BP has increased gradually over time, lowering of the BP should occur less quickly (eg, hours to days) (algorithm 2). (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Hypertensive urgency'.)

Management of hypertensive urgencies is discussed in greater detail separately. (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Hypertensive urgency'.)

INITIAL STABILIZATION — The initial stabilization and management of hypertensive emergencies and urgencies in children is provided in the algorithms (algorithm 1 and algorithm 2). Once the patient is stabilized, the physician should perform a more in-depth assessment to identify the underlying cause.

Maintain airway, breathing, and circulation — Children with hypertensive emergencies may rapidly develop heart failure, seizures, and/or altered mental status. They should be managed in an emergency or critical care setting where continuous monitoring and rapid support of airway, breathing, and circulation can occur. (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Initial stabilization'.)

Confirm elevated blood pressure — Simultaneous with supportive measures, blood pressure (BP) values >90^th percentile in children <13 years of age or >130/80 for adolescents ≥13 years of age that are obtained by oscillometric methods warrant confirmation by auscultation, whenever possible [2,8]. Accurate BP measurement requires use of the proper cuff size, which consists of a bladder width that is approximately 40 percent of the circumference of the upper arm measured midway between the olecranon and the acromion, and a cuff bladder length that encircles 80 to 100 percent of the circumference of the upper arm midway between the olecranon and the acromion. The bladder width-to-length ratio should be at least 1:2 (figure 2). Patients who newly present with acute hypertension should also have BP taken in all four limbs; lower extremity BP that is less than upper extremity BP or significant difference between right and left upper extremity BP suggests coarctation of the aorta. (See "Definition and diagnosis of hypertension in children and adolescents", section on 'Technique of blood pressure measurement'.)

If manual BP measurement is not possible, repeat automated BP readings may be substituted; the same guidance regarding cuff size should be followed.

Once markedly elevated BP is confirmed, a reliable method for obtaining frequent repeat BPs using either an intra-arterial line or an oscillometric device should be established to assist with ongoing management. In the setting of a hypertensive emergency, treatment should not be delayed to obtain arterial cannulation.

Evaluate for target-organ damage — If the BP remains elevated on repeat measurement, a focused history and physical examination should be performed to identify evidence of end-organ damage (eg, hypertensive encephalopathy, heart failure, or renal disease). An acute severe symptomatic elevation in BP with evidence of acute target-organ damage defines a hypertensive emergency and, after exclusion of conditions that alter initial BP management, warrants emergency lowering of BP using intravenous (IV) therapy.

Signs of target-organ damage — The most common sites of target-organ damage in children with hypertensive emergency include the brain, heart, eyes, and kidneys [6,7].

●Central nervous system (CNS) – CNS findings may include headache (most common complaint), altered mental status (lethargy, coma, or confusion), seizures, and irritability (infants) [1,6,7,9]. When these symptoms are associated with white matter edema on neuroimaging, patients should be considered to have reversible posterior leukoencephalopathy syndrome (RPLS). Facial nerve palsy (most frequently unilateral), vision change, and hemiplegia are other reported CNS findings in children with hypertensive emergencies [10].

●Eye – Funduscopic examination is of particular importance because papilledema and retinal hemorrhage or exudates may be the only signs of a hypertensive emergency (picture 1A-B). (See "Moderate to severe hypertensive retinopathy and hypertensive encephalopathy in adults" and "Ocular effects of hypertension".)

●Heart – Heart failure secondary to a hypertensive emergency may have findings of left ventricular heart failure (tachypnea, pulmonary edema, S3 or S4 gallop rhythm, and new or changed heart murmur). (See "Approach to diagnosis and evaluation of acute decompensated heart failure in adults".)

●Renal – Hematuria and proteinuria may represent manifestations of glomerulonephritis, a common cause of hypertensive emergency. Peripheral edema suggests fluid overload in association with renal disease. Acute, severe hypertension can cause acute kidney injury.

Identify conditions that alter initial blood pressure management — Prior to antihypertensive therapy, it is imperative to identify the following patient populations:

●Patients for whom rapid BP lowering is contraindicated – These patients have conditions in which rapid lowering of BP may cause organ ischemia:

•Patients with increased intracranial pressure – Differentiation of intracranial hypertension from hypertensive encephalopathy often requires emergency neuroimaging prior to antihypertensive therapy to exclude mass lesion, hemorrhage, or stroke. Head trauma is also suggested by history and the presence of a bulging fontanelle in infants, bruising, laceration, hemotympanum (picture 2), palpable skull defect, or signs of impending hernia (figure 3). (See "Severe traumatic brain injury (TBI) in children: Initial evaluation and management", section on 'Physical examination'.)

Hypertensive encephalopathy is a diagnosis of exclusion, confirmed retrospectively when neurologic symptoms improve after the BP is lowered into a more normal range. By contrast, other causes of increased intracranial pressure (eg, brain mass lesion, stroke, or cerebral hemorrhage) are not managed by reducing BP. (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Conditions that alter initial treatment'.)

Patients with mass lesions frequently have a progressive headache over several days to weeks that often awakens them from sleep or is accompanied by morning vomiting. Physical signs of mass lesions include ataxia, diplopia, and focal neurologic findings. (See "Elevated intracranial pressure (ICP) in children: Clinical manifestations and diagnosis", section on 'Clinical manifestations'.)

Patients with known CNS vascular disease (eg, patients with sickle cell disease or moyamoya disease) may have a history of prior transient ischemic attacks or strokes and may have a higher BP goal.

•Coarctation of the aorta – Coarctation of the aorta is suggested by diminished femoral pulses, lower extremity BP that is less than upper extremity BP, or significant difference between right and left upper extremity BP. Midaortic syndrome may present similarly to thoracic aortic coarctation. (See "Clinical manifestations and diagnosis of coarctation of the aorta", section on 'Clinical manifestations'.)

●Patients who require therapy directed at the underlying cause – These patients have conditions such as:

•Severe pain that requires analgesia (eg, fentanyl or morphine).

•Preeclampsia or eclampsia in females during late pregnancy (typical >34 weeks gestation) or the early postpartum period. (See "Preeclampsia: Clinical features and diagnosis" and "Preeclampsia: Antepartum management and timing of delivery".)

•Cocaine, amphetamine, or other sympathomimetic overdose – These patients have a history of drug ingestion or signs of sympathomimetic overdose (toxidrome) (table 6). (See "Cocaine: Acute intoxication", section on 'Cardiovascular complications' and "Acute amphetamine and synthetic cathinone ("bath salt") intoxication", section on 'Hypertension'.)

•Pheochromocytoma – Pheochromocytoma is suggested by intermittent headaches, flushing, tachycardia, palpitations, and diaphoresis. (See "Pheochromocytoma and paraganglioma in children", section on 'Medical preparation for surgery'.)

•Envenomation with sympathetic hyperactivity – These patients live in regions where scorpions or jellyfish reside and present with a history of a sting or typical physical findings. (See "Scorpion envenomation causing autonomic dysfunction (North Africa, Middle East, Asia, South America, and the Republic of Trinidad and Tobago)" and "Jellyfish stings", section on 'Irukandji syndrome (generalized pain and severe hypertension)'.)

Treat hypertensive emergency or urgency — The treatment of hypertensive emergencies and urgencies in children is discussed separately (algorithm 1 and algorithm 2). (See "Initial management of hypertensive emergencies and urgencies in children" and "Management of hypertension in neonates and infants", section on 'Severe symptomatic hypertension'.)

FURTHER EVALUATION — After initial stabilization and treatment, further evaluation consists of a complete history, physical examination, and ancillary studies to identify the underlying etiology.

History — The history should focus on findings referable to organs that are frequently affected in hypertensive emergencies. These include the eyes, brain, heart, adrenal gland, thyroid gland, and kidneys (table 7) [11-15]:

●Hematuria and/or proteinuria accompanied by edema or diminished urine output in the absence of trauma – Suggests glomerulonephritis or other parenchymal renal disease. (See "Glomerular disease: Evaluation in children".)

●Abdominal pain, vomiting, and bloody diarrhea – Supports hemolytic-uremic syndrome as a likely etiology.

●History of umbilical artery or vein catheterization – In neonates and infants, predisposes to renovascular disease. (See "Etiology, clinical features, and diagnosis of neonatal hypertension".)

●Preceding streptococcal infection involving the skin or pharynx – Points to poststreptococcal glomerulonephritis. (See "Group A streptococcus: Virulence factors and pathogenic mechanisms".)

●Pregnancy (typically 34 weeks gestation or later) or postpartum – Suggests preeclampsia or eclampsia. (See "Preeclampsia: Clinical features and diagnosis", section on 'Clinical presentation'.)

●Illicit, prescription, and over-the-counter drug abuse – Drugs associated with hypertension in overdose include cocaine, amphetamines, anabolic steroids, phencyclidine (PCP), pseudoephedrine, ephedra-containing alternative medications, oral contraceptives, and corticosteroids. (See "Cocaine: Acute intoxication", section on 'Cardiovascular complications' and "Phencyclidine (PCP) intoxication in children and adolescents", section on 'Clinical features of overdose' and "MDMA (ecstasy) intoxication", section on 'Clinical features' and "Methamphetamine: Acute intoxication", section on 'Clinical features'.)

●Recent use of serotonergic agents or inadvertent coadministration of serotonergic medications causing serotonin syndrome. (See "Serotonin syndrome (serotonin toxicity)".)

●Weight loss, anxiety, and heat intolerance suggesting hyperthyroidism. (See "Clinical manifestations and diagnosis of Graves disease in children and adolescents".)

●Symptoms of catecholamine excess such as intermittent tachycardia, palpitations, pallor, headaches, and/or diaphoresis suggest pheochromocytoma. (See "Pheochromocytoma and paraganglioma in children".)

●History of trauma to the flank potentially leading to a compressive renal hematoma. (See "Management of blunt and penetrating renal trauma".)

●Known history of kidney disease – Acute volume overload in an anuric patient can present with hypertensive emergency.

Physical examination — In addition to signs of target-organ damage (see 'Signs of target-organ damage' above), the clinician should carefully examine the patient for clues to the underlying etiology for the hypertensive emergency or urgency (table 8):

●Bruising and/or laceration of the face or scalp, palpable skull defect, or hemotympanum suggesting head trauma with intracranial bleeding

●In infants, bulging fontanelle or increased head circumference suggesting increased intracranial pressure

●Exophthalmos and thyromegaly associated with hyperthyroidism (see "Clinical manifestations and diagnosis of Graves disease in children and adolescents")

●Diminished femoral pulses relative to brachial pulses or disparities in four extremity blood pressures (BPs) indicating coarctation of the aorta (see "Clinical manifestations and diagnosis of coarctation of the aorta")

●Abdominal mass suggesting Wilms tumor, neuroblastoma, polycystic kidney disease, or other congenital renal anomaly

●Abdominal or flank bruit suggestive of renovascular disease

●Edema suggestive of underlying renal disease

●Bruising over the flank suggestive of renal trauma

●Ataxia, papilledema, dysmetria, visual field defects, or focal neurologic deficits suggestive of a mass brain lesion

●Skin findings suggesting neurofibromatosis (eg, cafe au lait spots, axillary freckling, cutaneous neurofibromas) or tuberous sclerosis (eg, Shagreen [ash leaf] patches, angiofibromas of the malar region of the face, ungual fibromas) (see "Neurofibromatosis type 1 (NF1): Pathogenesis, clinical features, and diagnosis", section on 'Clinical manifestations' and "Tuberous sclerosis complex: Clinical features")

Ancillary studies — All patients with a hypertensive emergency warrant the following studies (table 9) (see "Evaluation of hypertension in children and adolescents", section on 'Laboratory evaluation'):

●Measurement of blood urea nitrogen (BUN), serum creatinine, electrolytes, and glucose; and urinalysis with microscopy. These tests quickly assess renal function and may indicate the presence of renal disease.

●Complete blood count and reticulocyte count to assess for possible anemia or thrombocytopenia often associated with hemolytic uremic syndrome and rheumatic disorders with significant renal involvement (eg, systemic lupus erythematosus).

●Chest radiograph and electrocardiogram (ECG) to screen for evidence of cardiomegaly or pulmonary edema. Where readily available, echocardiography provides more specific information regarding left ventricular mass and function than does cardiac examination or ECG in patients with findings of heart failure. Hypotension and cardiogenic shock have been reported in infants with severe hypertension where the hypertension was unmasked only when heart function improved [16].

Additional studies are dictated by the clinical setting:

●Patients with headache, seizures, papilledema, or focal neurologic findings warrant emergency neuroimaging to assess for intracranial hemorrhage, mass brain lesion, or stroke. Hypertensive encephalopathy is a diagnosis of exclusion, confirmed retrospectively when neurologic symptoms improve after the BP is lowered into a more normal range. By contrast, other causes of increased intracranial pressure (eg, brain mass lesion, stroke, or cerebral hemorrhage) are not initially managed by reducing BP. (See "Initial management of hypertensive emergencies and urgencies in children", section on 'Conditions that alter initial treatment'.)

●Urine toxicological screen testing for amphetamines, PCP, and metabolites of cocaine in patients with a sympathomimetic toxidrome.

●Further studies in patients with persistent hypertension, end-organ damage, primary hypertension, or secondary hypertension are discussed separately. (See "Evaluation of hypertension in children and adolescents", section on 'Laboratory evaluation' and "Evaluation of hypertension in children and adolescents", section on 'Further evaluation'.)

ETIOLOGY OF HYPERTENSIVE EMERGENCY — In contrast to adults, where uncontrolled primary hypertension (formerly called "essential" hypertension) is the overwhelming cause of a hypertensive emergency, children are more likely to have secondary hypertension [6,9]. The etiology of hypertensive emergencies varies significantly by age and largely parallels underlying causes of hypertension (table 10 and table 11) [17,18]. (See "Evaluation of hypertension in children and adolescents" and "Etiology, clinical features, and diagnosis of neonatal hypertension" and "Epidemiology, risk factors, and etiology of hypertension in children and adolescents".)

Neonate — Infants with hypertensive emergencies typically have renovascular disease or congenital renal anomalies. The majority of neonatal renovascular disease is caused by umbilical-arterial catheterization with subsequent thromboembolism of either the aorta or renal arteries. Other age-specific causes include coarctation of the aorta, renal vein thrombosis, renal parenchymal disease, bronchopulmonary dysplasia, congenital adrenal hyperplasia, and iatrogenic fluid overload. (See "Etiology, clinical features, and diagnosis of neonatal hypertension".)

Children — Children outside of the neonatal period with hypertensive emergencies commonly have underlying kidney disease, renovascular disease, or endocrine disease. (See "Epidemiology, risk factors, and etiology of hypertension in children and adolescents", section on 'Secondary hypertension'.)

Adolescents — Although renal parenchymal disease and renovascular hypertension are also frequent causes of secondary hypertension in this age group, other etiologies such as preeclampsia, sympathomimetic drug intoxication (eg, cocaine, amphetamine exposure) should be considered [17]. Primary hypertension leading to hypertensive urgency and emergency are also common in this age group [7]. (See "Preeclampsia: Clinical features and diagnosis" and "Cocaine: Acute intoxication".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hypertensive emergencies and urgencies in children".)

SUMMARY AND RECOMMENDATIONS

●Definitions – The definition of childhood hypertension is statistically defined based upon the normative distribution of blood pressure (BP) in normal-weight children and is stratified by sex, age, and height (figure 1A-B and table 1 and table 2). (See "Definition and diagnosis of hypertension in children and adolescents".)

Recognition of hypertension in neonates and infants also depends on comparison with standards. However, these BP measurements are adjusted for differing parameters than in children over one year of age: birth weight and postconceptual age for neonates (table 4); age and, to a limited extent, weight and length for the perinatal period up to one year of age (figure 1A-B). (See "Evaluation and diagnosis of hypertension in infants between one month and one year of age", section on 'Normal blood pressure' and "Etiology, clinical features, and diagnosis of neonatal hypertension", section on 'Normal blood pressure'.)

Severe hypertension, or hypertensive crisis, has traditionally been divided into hypertensive emergencies (acute severe symptomatic elevation in BP with evidence of potentially life-threatening symptoms or target-organ damage [eg, hypertensive encephalopathy, heart failure, or renal disease]) and hypertensive urgencies (acute severe elevation in BP without life-threatening symptoms or evidence of acute target-organ damage). However, clinical judgment must be used to gauge the severity of hypertension and its potential for life-threatening end-organ damage that determines the timing and intensity of management. (See 'Definition' above.)

●Hypertensive emergency stabilization – Pediatric patients should be referred to an immediate source of care (eg, emergency department) if they have serious symptoms and the BP value is at the stage 2 level (table 3), or the BP is >30 mm Hg above the 95th percentile for children less than 13 years of age or >180/120 in an adolescent (table 1 and table 2). Initial management of these patients includes (see 'Hypertensive emergency' above and 'Initial stabilization' above):

•Support airway, breathing, and circulation

•Simultaneous with stabilization, confirm BP elevation

•Determine if signs of end-organ damage are present

•Identify conditions that alter BP management

●Initial treatment – Treatment of hypertensive emergencies and urgencies in children is described in the algorithms (algorithm 1 and algorithm 2) and discussed in detail separately. (See "Initial management of hypertensive emergencies and urgencies in children".)

●Further evaluation – After initial stabilization and treatment, further evaluation consists of a complete history, physical examination, and ancillary studies to identify the underlying etiology (table 7 and table 8). (See 'Further evaluation' above.)

●Etiology – The etiology of pediatric hypertensive emergencies and urgencies varies significantly by age and largely parallels underlying causes of hypertension (table 10 and table 11). (See 'Etiology of hypertensive emergency' above.)

ACKNOWLEDGMENT — The editorial staff at UpToDate acknowledge Jordan Symons, MD and Brianna Enriquez, MD, who contributed to earlier versions of this topic review.