Basics
Description
- Hypertension: average systolic and/or diastolic blood pressure (BP) above the 95th percentile for age, gender, and height percentile on at least 3 separate occasions
- Prehypertension: BP between the 90th percentile and 95th percentile or BP ≥120/80 mm Hg in adolescents
- Stage 1 hypertension: BP 95-99% plus 5 mm Hg
- Stage 2 hypertension: BP >99th% plus 5 mm Hg
- Primary (essential) hypertension: hypertension for which there is no underlying cause
- Secondary hypertension: hypertension for which an underlying cause can be identified
- White coat hypertension: elevated BP readings in a medical setting with normal BP on ambulatory blood pressure monitoring (ABPM)
- Masked hypertension: normal BP readings in a medical setting with elevated BP readings on ABPM
Epidemiology
- Primary hypertension is now identifiable in children and adolescents and is associated with overweight status, metabolic syndrome, and family history of hypertension.
- The prevalence of hypertension is increasing due to the epidemic of youth obesity and the metabolic syndrome.
- Hypertension in the pediatric population is estimated to be between 1% and 4%.
- 30% of children with body mass index (BMI) >95% have prehypertension or hypertension.
Risk Factors
- Primary hypertension: obesity, sedentary lifestyle, low birth weight, smoking, alcohol use, hyperlipidemia, family history, stress, sodium intake, sleep apnea
- Secondary hypertension: renal or urologic disease, transplant, congenital heart disease, umbilical artery catheterization, urinary tract infection (UTI), diabetes mellitus, elevated intracranial pressure, or medications known to raise BP
- The younger the child and the more elevated BP, the greater likelihood of a secondary cause.
Genetics
- The genetic basis of primary hypertension is polygenic but more likely to develop in individuals when there is a strong family history.
- The genetics of secondary causes depend on the underlying condition, for example
- Polycystic kidney disease: autosomal dominant, autosomal recessive
- Neurofibromatosis: autosomal dominant
- Glucocorticoid-remediable aldosteronism: autosomal dominant
General Prevention
Avoidance of excess weight gain and regular physical activity can prevent obesity-related hypertension.
Etiology
- Secondary causes
- Renal: acute glomerulonephritis, chronic renal failure, polycystic kidney disease, reflux nephropathy
- Renovascular: fibromuscular dysplasia, neurofibromatosis, vasculitis
- Cardiac: coarctation of the aorta
- Endocrine: pheochromocytoma, hypo/hyperthyroid, neuroblastoma, glucocorticoid-remediable aldosteronism, Conn syndrome, apparent mineralocorticoid excess, congenital adrenal hyperplasia, Liddle syndrome, Gordon syndrome
- Neurologic: increased intracranial pressure
- Drugs: corticosteroids, oral contraceptives, sympathomimetics, illicit drugs (cocaine, phencyclidine)
- Other: pain, burns, traction
- Reduced nephron number secondary to premature birth, low birth weight, or postnatal insults are associated with hypertension.
Pathophysiology
Blood pressure is a product of cardiac output and total peripheral vascular resistance. Increases of either or both of these products lead to hypertension. The various causes of hypertension alter blood pressure through different mechanisms such as volume overload (sodium retention, excess sodium intake), volume distribution, renin-angiotensin excess, sympathetic activation, insulin, and endothelin.
Diagnosis
- Hypertensive emergency: severely elevated BP with evidence of target organ injury (encephalopathy, seizures, renal damage)
- Hypertensive urgency: severely elevated BP with no evidence of secondary organ damage
History
- Headache, blurry vision, epistaxis, unusual weight gain or loss, chest pain, flushing, fatigue
- UTIs can be associated with reflux nephropathy and hypertension.
- Gross hematuria, edema, and fatigue may suggest renal disease.
- Birth history: umbilical artery catheterization
- Medications: corticosteroids, cold preparations, oral contraceptives, illicit drugs
- Family history: hypertension, diabetes, obesity, familial endocrinopathies, renal disease
- Trauma: arteriovenous (AV) fistula, traction
- Review of symptoms: sleep apnea, obesity
Physical Exam
- BP
- Children >3 years of age should have their BP measured during a health care episode or younger if they have any risk factors for hypertension.
- Child should be seated quietly for 5 minutes, feet on the floor with the right arm supported at the level of the heart. Routine BPs are measured in the right arm.
- Use the proper cuff size. The inflatable bladder should completely encircle the arm and cover ~80-100% of the upper arm. A cuff that is inappropriately small will artificially increase the measurement.
- Elevated BPs obtained by oscillometric devices should be repeated by auscultation.
- When hypertension is confirmed, BP should be measured in both arms and in a leg. Normally, BP is 10-20 mm Hg higher in the legs. If leg BP is lower than arm, consider coarctation of the aorta.
- Tachycardia in hyperthyroidism, pheochromocytoma
- Body habitus: thin, obese, growth failure, virilized, stigmata of Turner or Williams syndromes
- Skin: caf © au lait spots, neurofibromas, rashes, acanthosis, malar rash
- Head/neck: moon facies, thyromegaly
- Eyes: funduscopic changes, proptosis
- Lungs: rales
- Cardiovascular: rub, gallop, murmur, femoral pulses
- Abdomen: mass, hepatosplenomegaly, bruit
- Genitalia: ambiguous, virilized
- Neurologic: Bell palsy
Diagnostic Tests & Interpretation
Lab
- The laboratory evaluation to determine the cause of hypertension should proceed in a stepwise fashion. In adolescents with stage 1 hypertension, it is reasonable to evaluate for white coat hypertension using ABPM as a first step before other testing.
- Patients should have the following: urinalysis, serum electrolytes, blood urea nitrogen, creatinine, calcium, cholesterol, CBC, ECG, echocardiogram (the most sensitive study to monitor end-organ changes), renal ultrasound, retinal exam
- Further evaluation is based on history, physical exam, and/or to prove secondary causes: voiding cystourethrogram, DMSA renal scan, 3D CT angiogram, MRA, urine or plasma for catecholamines and metanephrines, plasma renin activity, aldosterone levels
- More invasive studies include renal angiogram; renal vein renin concentrations; meta-iodobenzylguanidine (MIBG) scan; renal biopsy; genetic studies to identify rare causes of hypertension
Diagnostic Procedures/Other
- Ambulatory BP monitoring refers to a procedure in which a portable BP device, worn by the patient, records BP over a specified period, usually 24 hours.
- Ambulatory BP monitoring may be helpful in cases in which the diagnosis of hypertension is uncertain (e.g., white coat hypertension) or in assessing the effectiveness of antihypertensive agents. ABPM may also be useful in assessing children at high risk of cardiovascular disease (e.g., diabetes mellitus, labile hypertension).
- Systolic hypertension on ABPM is a better predictor for the development of left ventricular hypertrophy (LVH) when compared to office BP measurements.
Differential Diagnosis
The initial objective after diagnosing hypertension in children is distinguishing primary from secondary causes. Generally, the younger the child and more elevated the BP measurements, the more likely the cause of hypertension is secondary.
Treatment
Medication
- Classes of antihypertensive agents include α- and β-blockers, diuretics, vasodilators (direct and calcium channel blockers), ACE inhibitors, and angiotensin receptor blockers (ARBs).
- Therapy should be initiated with a single drug.
- Avoid multiple medications with the same mechanism of action.
- Elicit a history of adverse effects and adjust medications accordingly.
- Specific classes should be used with concurrent medical conditions: ACE inhibitors or ARBs in children with diabetes and microalbuminuria or proteinuric renal diseases; β-blockers or calcium channel blockers with migraine headaches.
- Certain classes of medication should be avoided in patients with specific conditions, such as asthma and diabetes (β-blockers) and bilateral renal artery stenosis (ACE inhibitors).
- ACE inhibitors are associated with congenital malformations and are contraindicated during pregnancy; calcium channel blockers and β-blockers are alternatives.
Additional Therapies
General Measures
- If BP is >95th percentile, it should be repeated on 2 more occasions.
- If BP is >99th percentile plus 5 mm Hg, prompt referral for evaluation and therapy should be made.
- If the patient is symptomatic, immediate referral and treatment are indicated.
- Mild primary hypertension may be managed with nonpharmacologic treatment: weight reduction, exercise, sodium restriction, avoidance of certain medications such as pseudoephedrine.
- Pharmacologic therapy should be directed to the cause of secondary hypertension when this is known or for severe, sustained hypertension.
- Medications may be needed in children with mild to moderate hypertension if nonpharmacologic therapy has failed or if end-organ changes, kidney disease, or diabetes is present.
Additional Therapies
- Regular aerobic physical activity (30-60 minutes at least 5 days a week)
- Limitation of sedentary activities to <2 hours per day
- Patients with uncontrolled stage 2 hypertension should be restricted from high-static competitive sports until the BP is in normal range.
Surgery/Other Procedures
- Dialysis may be needed for hypertension in chronic renal failure.
- Surgical correction of renovascular hypertension and coarctation of the aorta. Percutaneous transluminal angioplasty has been used for renal artery stenosis.
Inpatient Considerations
Initial Stabilization
- Hypertensive emergencies should be treated with IV BP medications, aiming to decrease the BP by 25% over the first 8 hours and gradually normalizing BP over 24-48 hours.
- Hypertensive urgencies can be treated by either IV or PO antihypertensives depending on symptomatology.
Admission Criteria
- Hypertensive emergencies should be admitted to the ICU if indicated.
- Hypertensive urgencies should be admitted to the hospital.
Ongoing Care
Follow-up Recommendations
Patient Monitoring
- The reduction of BP with medication should be gradual to avoid side effects.
- Ongoing monitoring is required for medication side effects, such as exercise intolerance (β-blockers), headaches (vasodilators), renal insufficiency or hyperkalemia (ACE inhibitors), or hypokalemia (diuretics).
- Regular monitoring for development of LVH (echo or ECG) is recommended.
- Patients with white coat hypertension require ongoing monitoring, as they are at risk for developing true hypertension.
Diet
- Dietary increase in fresh vegetables, fresh fruits, potassium, fiber, and nonfat dairy
- Restriction of sodium, calories, saturated fat, and refined sugar
- Low-sodium (DASH) diet: <2.3 g of sodium per day for adolescents
Patient Education
- Diet
- Increase in fresh vegetables, fresh fruits, fiber, and nonfat dairy
- Restriction of sodium and calories
- Activity
- Regular aerobic physical activity (30-60 minutes at least 5 days a week)
- Limitation of sedentary activities to <2 hours per day
- Prevention
- Avoidance of excess weight gain, smoking, and alcohol use; regular physical activity
Prognosis
The patient's prognosis depends on the underlying cause of the hypertension. It is excellent if the BP is well controlled.
Complications
- LVH and heart failure
- Renal failure
- Encephalopathy
- Retinopathy
Additional Reading
- Feld LG, Corey H. Hypertension in childhood. Pediatr Rev. 2007;28(8):283-298. [View Abstract]
- McCambridge TM, Benjamin HJ, Brenner JS, et al. Athletic participation by children and adolescents who have systemic hypertension. Pediatrics. 2010;125(6):1287-1294. [View Abstract]
- McCrindle B. Assessment and management of hypertension in children and adolescents. Nat Rev Cardiol. 2010;7(3):155-163. [View Abstract]
- National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004;114(2):S555-S576. [View Abstract]
- Suresh S, Mahajan P, Kamat D. Emergency management of pediatric hypertension. Clin Pediatr. 2005;44(9):739-745. [View Abstract]
- Urbina E, Alpert B, Flynn J, et al. Ambulatory blood pressure monitoring in children and adolescents: recommendations for standard assessment. Hypertension. 2008;52(3):433-451. [View Abstract]
Codes
ICD09
- 401.9 Unspecified essential hypertension
- 405.99 Other unspecified secondary hypertension
- 405.19 Other benign secondary hypertension
- 405.91 Unspecified renovascular hypertension
- 405.11 Benign renovascular hypertension
ICD10
- I10 Essential (primary) hypertension
- I15.9 Secondary hypertension, unspecified
- I15.1 Hypertension secondary to other renal disorders
- I15.8 Other secondary hypertension
- I15.0 Renovascular hypertension
- I15.2 Hypertension secondary to endocrine disorders
SNOMED
- 38341003 Hypertensive disorder, systemic arterial (disorder)
- 31992008 Secondary hypertension (disorder)
- 697930002 Labile hypertension due to being in a clinical environment (disorder)
- 59997006 Endocrine hypertension (disorder)
- 28119000 Renal hypertension (disorder)
- 194788005 hypertension secondary to endocrine disorder (disorder)
FAQ
- Q: What is the value of ambulatory BP monitoring?
- A: This device is similar to a Holter monitor and measures BPs over a 24-hour period while the patient is awake and asleep. By reviewing the BPs, one can determine if a significant proportion of readings are elevated and whether or not the normal dip in BP during sleep is seen. Thus, conditions such as white coat hypertension can be verified or discounted.
- Q: What are the indications for invasive studies, such as angiography?
- A: This decision should be individualized and based on the severity of the hypertension, response to medication, the clinical presentation (e.g., neurofibromatosis), and results of other studies. In general, young children and all children with severe, unexplained hypertension should be completely evaluated.
- Q: Can adolescents with elevated BP compete in sports?
- A: Adolescents with hypertension should be encouraged to participate in athletics if their BP is well controlled. The use of stress testing in this population is controversial.
- Q: Do I need to worry about isolated systolic hypertension?
- A: Studies in adults have shown that sustained systolic hypertension may be just as important as diastolic hypertension.