Paediatrics: Hypertension: causes and features

Hypertension: causes and features

Causes of hypertension

Primary (essential) hypertension

This is a diagnosis of exclusion. High body mass index, excessive salt intake, lack of exercise, and family history may be underlying predispos-ing factors

Secondary hypertension

·  Renal (commonest cause in hospital referral practice):

o chronic renal parenchymal disease (reflux/scarring)

o polycystic kidney disease

o obstructive uropathy

o acute nephritis

o chronic renal failure

·  Vascular:

o umbilical arterial/venous catheters

o renal artery stenosis

o renal vein thrombosis

o coarctation of aorta

o vasculitis

·  Endocrine:

o congenital adrenal hyperplasia

o hyperthyroidism

o increased steroids (iatrogenic or endogenous)

o phaeochromocytoma (BP intermittently raised)

o hyperaldosteronism

·  Trauma

·  Neurological:

o 2° to pain

o raised intracranial hypertension

·  Tumours:

o neuroblastoma

o Wilms

·  Medication:

o steroids

o aminophylline/caffeine

o oral contraceptive pill

o erythropoietin

o calcineurin inhibitors; decongestants

o amphetamines; cocaine

·  Others:

      bronchopulmonary dysplasia

      ECMO

      ‘white-coat’ hypertension

Clinical features

Most are asymptomatic.

Infants

·Vomiting.

·Failure to thrive (rare).

·Congestive cardiac failure/respiratory distress (in newborns).

Children

·Headache/nausea and vomiting.

·Visual symptoms.

·Irritable/tired.

·Bell’s palsy.

·Epistaxis.

·Growth failure.

·Fits.

·Altered consciousness.

Examination

·Check fundi.

·Feel abdomen for abdominal masses.

·Listen for renal bruits.

·Feel femoral pulses and compare to radial/brachial pulses (to exclude

·coarctation) and check BP in all 4 limbs.

·Examination of the heart.

Investigations

A s cause is more likely with severe hypertension. Treatment and inves-tigations may need to proceed together.

·Urine:

·  urinalysis, microscopy, and culture;

·  vanillylmandelic acid (VMA):creatinine ratio;

·  steroid profile and toxicology.

·Blood tests:

      FBC;

      U&E and creatinine;

      bicarbonate, calcium, phosphate, albumin;

      plasma renin and aldosterone.

·CXR and ECG.

·ECG.

·US of urinary tract + Doppler if renal artery stenosis suspected.

·Further imaging will depend upon suspected cause and ultrasound

·findings, e.g. DMSA, CT scan, arteriogram.

·Specialized tests, e.g. for phaeochromocytoma.