Hypertension in children
REMEMBER
- Systemic hypertension when present, usually indicates the underlying disease.
- Blood pressure(BP) that is consistently above the 95th percentile for age requires further evaluation
- Checking BP should be part of the routine annual examination in children >3 years of age.
Classification
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Normal BP < 90th centile for age and height
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Pre-hypertension- 90th to 95th centile for age and height
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Stage 1 Hypertension- 95th to 99th centile for age and height
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Stage 2 Hypertension – Above > 99th centile for age and height
Conditions Associated with Transient or Intermittent Hypertension in Children
RENAL
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Acute postinfectious glomerulonephritis
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Henoch-Schönlein purpura
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Hemolytic-uremic syndrome
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Acute tubular necrosis
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After renal transplantation (immediately and during episodes of rejection)
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Hypervolemia
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After surgical procedures on the genitourinary tract
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Pyelonephritis
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Renal trauma
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Leukemic infiltration of the kidney
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Obstructive uropathy associated with Crohn disease
DRUGS/ MEDICATIONS –
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Oral contraceptives
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Sympathomimetic agents
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Corticosteroids and adrenocorticotropic hormone
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Antihypertensive withdrawal
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Vitamin D intoxication
CENTRAL NERVOUS SYSTEM CAUSES –
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Increased intracranial pressure
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Guillain-Barré syndrome
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Burns
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Posterior fossa lesions
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Porphyria
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Encephalitis
OTHER CAUSES
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Fractures
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Chronic airway disease
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Electrolyte imbalance- Hypercalcemia
EXAMINATION- Look out for below findings-
PHYSICAL EXAMINATION-
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Height, weight, body mass index
Features suggestive of syndromes
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Neurofibromatosis
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Multiple endocrine neoplasia
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Turner/ William/ Marfan/ Cushing/ hyperthyroidism/ congenital adrenal hyperplasia
Cardiovascular examination
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Pulse and BP (both arms and legs)
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Bruits/murmurs – heart, abdomen, flanks, back, neck, head
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Signs of left ventricular hypertrophy or cardiac failure
Abdomen Masses –
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Wilms/ neuroblastoma/ pheochromocytoma/ cystic kidney disease/ obstructive uropathy
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Hepatosplenomegaly
Neurological examination
Fundoscopy for hypertensive changes
BLOOD INVESTIGATIONS –
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Full blood count
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Renal functions and calcium
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Fasting plasma glucose
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Serum lipids
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Fasting serum triglycerides
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Plasma renin activity
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Plasma aldosterone concentration
URINE TESTS-
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Urinalysis (quantification of microalbuminuria and proteinuria)
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Urine and plasma catecholamines or metanephrines
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Urinary free cortisol/steroid analyses
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Molecular genetic studies
OTHER TESTS-
More sophisticated tests that should await results of above screening
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Chest Xray
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ECG and echocardiography
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Renal ultrasound/ Color Doppler
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Renal vein renin measurements
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Renal angiography
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Computed tomography/ Magnetic resonance imaging
MANAGEMENT-
AIMS OF TREATMENT-
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To reduce blood pressure < 95th percentile for age.
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Both medical and lifestyle changes are important.
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If lifestyle changes like weight reduction, reduction of salt intake, regular exercise don’t help, then medications are considered
DRUG TREATMENT-
ARTERIAL VASODILATORS
- Example- Hydralazine/ Sodium nitroprusside/ Minoxidil
ADRENERGIC ANTAGONISTS-
- Example- Esmolol/ Phentolamine/ Prazosin/ Propranolol/ atenolol/ labetalol
RENIN ANGIOTENSIN INHIBITORS –
- Example- Captopril/ Enalapril
CALCIUM CHANNEL BLOCKERS –
- Example-Nifedipine/ Amlodipine
DIURETICS –
- Example- Furosemide/ Bumetanide
MEDICATIONS BASED ON CAUSE OF HYPERTENSION-
Refer local kidney guidelines before starting treatment.
If excessive activity of renin-angiotensin-aldosterone system –
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Beta-blockers (propranolol) for suppression of renin secretion,
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ACE inhibitor (captopril or enalapril)
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Aldosterone antagonist (spironolactone).
ACE inhibitors used in –
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In high-renin hypertension (renovascular disease)
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Excess angiotensin production (neonates -occlusion of renal vessel by thrombus)
Use ?-Adrenergic blocking agents like phentolamine, phenoxybenzamine in
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Neural crest tumours which cause high catecholamines.
Consider Beta blockers to –
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Also control heart rate.
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In essential hypertension.
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In high-renin/ high cardiac output