A hypertensive emergency is severe hypertension with manifestations of damage to target organs (primarily the brain, eyes, cardiovascular system, and kidneys). Hypertensive emergencies are relatively rare in children, occurring in about 2 per 10,000 emergency department visits (1
(See also Hypertension in Children and Hypertensive Emergencies in adults.)
In the past, severe hypertension without target organ damage was called a hypertensive urgency, and severe hypertension with end-organ dysfunction or damage was called a hypertensive emergency. The separation of these two clinical states is somewhat arbitrary because a hypertensive urgency can progress to an emergency. Today, the preferred term is "acute severe hypertension," but the terms "urgency" and "emergency" are still used in clinical practice.
The American Academy of Pediatrics' 2017 guidelines for screening and management of high blood pressure in children and adolescents suggest that physicians should be concerned about acute target organ damage in patients whose blood pressure (BP) measurement is ≥ 30 mm Hg above the 95th percentile based on age, sex, and height (see BP percentile level tables for boys and girls). For older adolescents, the concerning BP is > 180/120. For these levels of severe hypertension, applying the term "hypertensive emergency" to children with target organ dysfunction or damage (primarily of the heart, brain, and/or kidneys) and applying the term "hypertensive urgency" to children with no symptoms and no target organ manifestations may help direct care because children with a hypertensive emergency need to be moved quickly to an emergency department or intensive care unit for evaluation, rapid testing, close monitoring, and IV treatment. Children with a hypertensive urgency also need to be quickly evaluated and treated by a physician who has experience treating children with severe hypertension, but BP does not need to be lowered as rapidly because these patients may have long-standing hypertension (which is why they do not have symptoms), and, at times, oral drugs can be used.
Importantly, children with acute secondary hypertension (particularly due to acute glomerulonephritis) can be symptomatic and even develop encephalopathy at BP levels that would be considered mild in a hypertensive adult or adolescent because, in addition to the BP level, the rate of rise is important because there is less time for the organ systems to adapt to the hypertension.
Marked BP elevation can affect several organ systems. The most common and critical are the
Brain: Hypertensive encephalopathy
Eyes: Retinal changes
Heart: Left ventricular heart failure
Kidneys: Renal insufficiency (elevated creatinine)
General reference
1. Wu HP, Yang WC, Wu YK, et al: Clinical significance of blood pressure ratios in hypertensive crisis in children. Arch Dis Child 97(3):200–205, 2012. doi: 10.1136/archdischild-2011-300373
Etiology
Hypertensive emergencies are usually the result of a rapid rise in BP, which may develop in children regardless of whether they have been previously diagnosed with hypertension.
The causes of acute severe hypertension vary significantly by age:
Infancy: Congenital renal disease, renal vascular disease, bronchopulmonary dysplasia, coarctation of the aorta, renal vein thrombosis
Childhood: Renal parenchymal disease, renal vascular disease, endocrine disorders, drug- or toxin-induced hypertension
Symptoms and Signs
BP is markedly elevated, typically to stage 2 hypertension levels or higher (see table Classification of Blood Pressure in Children).
In children, hypertensive emergencies manifest primarily as hypertensive encephalopathy, typically with headache, altered mental status (eg, lethargy, confusion, coma), seizures, and, in infants, irritability. These manifestations should resolve with lowering of BP.
Heart failure in hypertensive children may cause tachypnea, pulmonary edema, gallop rhythm, or a new or changed heart murmur.
Renal insufficiency is usually asymptomatic, but peripheral edema may be present.
Hypertensive retinopathy may be present, with papilledema, hemorrhages, and/or exudates.
Diagnosis
Blood pressure (BP) measurement
Testing for target organ involvement
Elevated BP should be measured using the proper technique for children. In a hypertensive emergency, BP measurements are usually taken with an oscillometric device, which facilitates the frequent (as often as every 2 to 3 minutes) measurements required. However, the initial measurement should be confirmed by auscultation.
Identification of conditions that would impact treatment is an immediate concern, especially an intracranial mass, uncorrected coarctation of the aorta, eclampsia, severe pain, sympathetic overactivity, or renal failure. In addition to history and physical examination findings, target organ involvement should be evaluated using tests that can be done quickly:
ECG and chest x-ray to evaluate for heart failure and ventricular hypertrophy—if possible, an echocardiogram, which is much more accurate
Urinalysis to screen for renal parenchymal disease
Complete blood count to screen for hemolytic-uremic syndrome
CT or MRI of the head if significant neurologic findings
Drug and pregnancy testing in adolescents
Hypertensive encephalopathy is a diagnosis of exclusion. Brain imaging is needed to rule out an intracranial mass or hemorrhage, which can be associated with high BP but require a different treatment approach than hypertensive encephalopathy.
If the patient's hypertension has not previously been diagnosed or evaluated, other testing to determine the etiology of the hypertension can be done later, after the patient is stabilized.
Treatment
For hypertensive emergencies, admission to an intensive care unit (ICU) and initiation of IV antihypertensive drugs (however, if an ICU bed is not available, it is best to keep the patient in the emergency department)
For hypertensive urgencies, hospital admission and initiation of antihypertensive therapy
(See also the American Academy of Pediatrics' 2017 guidelines for screening and management of high blood pressure in children and adolescents.)
For hypertensive emergencies, the goal is to expeditiously lower BP to levels that eliminate the threats to life and stop further damage to target organs. When possible, the child should be admitted to an ICU and treated by a physician experienced in managing severe hypertension in children. However, therapy should not be delayed if admission to an ICU and/or a specialist is not readily available. In this case, the child should be managed in an emergency department by the most experienced provider available. BP should be lowered fast enough to prevent end-organ damage but slow enough not to cause hypoperfusion of these organs. Continuous IV infusion of drugs is superior, with only a 4% complication rate, as compared to 23% with the use of IV bolus drugs. When IV infusions are used, BP should be monitored every 1 to 2 minutes; if technical skill and equipment are available, an arterial line should be placed to allow continuous monitoring of BP. However, therapy should not be delayed and monitoring BP using oscillometric or auscultatory methods is acceptable. A safe rate of lowering BP is to have the systolic BP decrease by 25% every 6 hours until the symptoms resolve. Then treatment can proceed more slowly until BP is ≤ the 95th percentile (or < 140/90 in children > 12 years). Importantly, previously normotensive children with acute hypertension can be treated more aggressively than children with long-standing hypertension, who are less likely to have symptoms but who are more likely to develop hypoperfusion and thus should have BP lowered more slowly.
Intravenous Drugs for Children With Severe Hypertension and Symptoms or Signs of Target Organ Damage
For hypertensive urgencies (asymptomatic severe hypertension with no manifestations of organ dysfunction), IV therapy is usually not required and oral drugs can be given (see table Oral Drugs for Children With Asymptomatic Severe Hypertension). Patients' symptoms and BP are monitored every 15 minutes to 1 hour to start and then less frequently depending on the decrease in BP and the patient remaining asymptomatic. After BP decreases and is stable, patients can be monitored every 1 to 4 hours. Therapy is adjusted to attempt to reach the 95th percentile or 130/80 over the next 24 to 72 hours. Patients are kept in the hospital until BP is stable on medications between the 95th percentile and the 95th percentile + 12 mm Hg or for older children 130-140/80-90.
Intravenous Drugs for Children With Severe Hypertension and Symptoms or Signs of Target Organ Damage
Drug (Class) | Dose | Adverse Effects | Comments |
|---|---|---|---|
First-line drugs | |||
Infusion: 0.25–3 mg/kg/hour IV; Initiate at low end dose and gradually titrate as needed to control blood pressure Bolus: 0.2–1 mg/kg IV every 10 to 20 minutes, increasing up to 40 mg/dose if needed | May cause bradycardia, wheezing | Relative contraindications for or caution should be used in patients with asthma or heart failure. | |
Infusion: Initially 0.5–1 mcg/kg/minute IV (may give initial one-time bolus of 30 mcg/kg not to exceed 2 mg prior to infusion) titrate upward every 15 to 30 minutes to maximum 4 mcg/kg/minute | May cause reflex tachycardia | ||
2nd-line drugs | |||
Bolus: 0.1–0.2 mg/kg up to 0.4 mg/kg per dose IV every 4 to 6 hours, maximum dose 20 mg (may be given IM but has an even slower onset of action) | Tachycardia, headache | Response to this drug varies in effect and rate. | |
Infusion: Starting 0.3 to 0.5 mcg/kg/minute IV increase every 3 to 5 minutes as needed to a maximum dose of 10 mcg/kg/minute (typical dose 3 to 4 mcg/kg/minute) | Cyanide toxicity with prolonged use (> 72 hours) or in renal failure May increase intracranial pressure | This drug is difficult to use. | |
2nd- or 3rd-line drug | |||
Infusion: 100–500 mcg/kg/minute IV | May cause profound bradycardia | This drug is contraindicated if a pheochromocytoma is possible. | |
Oral Drugs for Children With Asymptomatic Severe Hypertension
Drug (Class) | Dose | Adverse Effects | Comments |
|---|---|---|---|
For children < 12 years of age, use weight-based dosing: Initial dose 2–5 mcg/kg every 6 to 8 hours adjusted up to 10 mcg/kg; maximum dose may be given up to 4 times a day For children ≥ 12 years of age, use fixed dosing schedule: 0.1 mg 2 times a day increased by 0.1 mg a day as needed up to 0.4 mg 2 times a day | Significant drowsiness, fatigue, dizziness, dry mouth | ||
Initial dose 0.25 mg/kg every 6 to 8 hours increased as needed up to maximum 25 mg every 6 hours | Tachycardia, headache | Dosage adjustments are needed for children who have renal dysfunction. | |
Initial dose 0.05 to 0.1 mg/kg every 6 to 8 hours up to 5 mg using the immediate-release capsules | Common adverse effects: Flushing, peripheral edema Severe adverse effects: Angioedema | ||
0.1 to 0.2 mg/kg once a day up to 10 mg (may increase to every 8 to 12 hours) | Common adverse effects: Dizziness, prolonged hypotension, fluid retention Severe adverse effects: Heart failure, pulmonary edema, Stevens-Johnson syndrome | This drug causes significant reflex tachycardia and fluid retention, so may need to use with a beta-blocker and diuretic. Dosage adjustments are needed for children who have renal dysfunction. |
Key Points
Hypertensive emergencies involve target organ dysfunction caused by elevated BP.
Admit to intensive care unit and consult a specialist in pediatric hypertension, treat with IV therapy, but do not delay treatment if these assets are not immediately available.
Goal of initial therapy is to lower BP to stop end-organ damage quickly but not so fast as to cause hypoperfusion.
BP should be lowered by 25% every 6 hours until the 95th percentile is approached and any related symptoms of target organ dysfunction are gone.
Children who develop a severe hypertensive emergency on top of their chronic hypertension need a more cautious approach to lowering their BP.
More Information
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource
American Academy of Pediatrics: Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents (2017)
