MSSC_Hypertension in Children.pdf

Hypertension in Children Introduction • Hypertension in infancy and childhood is uncommon, and often undiagnosed. • It is defined as the lateral pressure exerted on the vessel wall by the blood in it. • Prevalence increases with age: 1-5% of children and adolescents are affected while up to 60% of...

Hypertension in Children Introduction • Hypertension in infancy and childhood is uncommon, and often undiagnosed. • It is defined as the lateral pressure exerted on the vessel wall by the blood in it. • Prevalence increases with age: 1-5% of children and adolescents are affected while up to 60% of individuals older than 65 years are affected Introduction • In children, BP correlates with age, sex, weight and height • Body mass index is the strongest determinant of BP in children; larger children tend to have higher BP than small children of the same age. • Note: LBW (due to fetal undernutrition) → decreased renal mass and changes in vascular structure predispose to future hypertension Introduction • Most childhood hypertension are Secondary as against Primary or Essential hypertension which predominate later in life. • To increase early detection, accurate BP measurement is imperative • Accurate BP measurement relies on: * patient being comfortable * proper use of equipment Measurement of BP • All children 3 years and above should have routine measurement of BP • Mercury sphygmomanometer is preferred to aneroid manometer • The child should be in a comfortable position, with the arm resting at the heart level Measurement of BP To obtain accurate readings, • appropriate cuff sizes must be used • the cuff should completely encircle the upper arm • the inflatable bladder should encircle at least 2/3 of the upper arm length and ¾ of its circumference Measurement of BP • Systolic BP corresponds to the onset of the tapping 1st korotkoff sound • Diastolic BP correlates with muffling or disappearance of the sounds • True diastolic BP probably lies b/w the muffling and the disappearance of korotkoff sounds Classification • Depends on the severity: • Normal: < 90th percentile • Prehypertension: 90th to < 95th or BP exceeds 120/80 mmHg even if below 90th percentile • Stage 1 Hypertension: 95th- 99th percentile • Stage 2 Hypertension: > 99th percentile plus 5mmHg Aetiology/Pathophysiology • BP is the product of CO and PVR; an increase in one or the other → increase in BP • Secondary Hypertension: arises from another disease process • Primary/Essential Hypertension: when no identifiable cause can be found; factors such as heredity, diet, stress, and obesity may play a role in its development. Secondary Hypertension • Most common in infants and younger children • Blood pressures range from mild to severe • In the newborn, it is often associated with umbilical artery catheterization and renal artery thrombosis • Hypertension in early childhood is generally due to renal disease Essential Hypertension • More often recognized in adults and adolescents than in children • Usually asymptomatic; BP elevation is usually mild • Often accompanied by a strong family history • Obesity genetic alterations in Ca and Na transport, vascular smooth muscle reactivity, and the RAS have been implicated Aetiology/pathophysiology Transient Hypertension can arise from: • AGN • Hemolytic uremic syndrome • Burns • Lead poisoning • Drugs: atropine, sympathomimetic drugs, steroids • Pyelonephritis • After renal trauma Sustained or Chronic Hypertension result from: • Renal: Chronic GN, reflux nephropathy, obstructive uropathy, polycystic kidney disease, CRF; renal artery stenosis, Wilm’s tumour • Coarctation of aorta • Endocrine: pheochromocytoma, neuroblastoma, CAH, Conn’s syndrome, Cushings syndrome Diagnosis Clinical • History of: • umbilical artery catheterization • diagnosis of coarctation • palpitation, headache, excessive sweating • UTI, renal surgery, oliguria • age of sexual development • family hx of HBP, obesity, stroke Diagnosis Physical Examination • General: accurate measurement of BPaverage of 3 readings • Presence of edema • Height, weight • Tarchycardia, absent or delayed pulses • Genitalia: ambiguous, virilization • Presence of neurologic deficts Laboratory Diagnosis • • • • • • • • • Complete Blood count Urinalysis with MCS S/EUCr, Ca CXR, ECG Lipid profile IVU Renal ultrasound Urine VMA, cathecolamines Renal biopsy Treatment Goals • To achieve a reduction of blood pressure below the 90th- 95th percentile for age, gender, and height • To prevent the long term effects of persistent hypertension Treatment Non Pharmacologic Treatment • Diet • Salt • Physical activity • Prevention of abnormal weight gain Pharmacological Treatment Indications for treatment with antihypertensive drugs • Symptomatic hypertension • Secondary hypertension • Stage 2 hypertension • Hypertension with established target organ damage • Hypertension with the presence of other risk factors for cardiovascular disease • Persistent hypertension despite lifesyle changes Antihypertensive drugs used in children • ACE inhibitors • Angiotensin-receptor blocker • Adrenergic blocking agents • Calcium channel blocker • Diuretics • Vasodilators Treatment • Initial treatment may be with a diuretic or a beta blocker for pts with essential hypertension • Volume-dependent hypertension respond adequately to diuretics • High renin, high CO respond best to beta blockers • ACE inhibitors and calcium channel blockers may offer the advantages of beta blockers but with fewer side effects Hypertensive Crisis • BP is rapidly rising or high BP is associated with neurological manifestations, HF or pulmonary oedema • Hypertensive Urgency: situation in which a reduction of BP is needed within hours, usu with oral medications • Hypertensive Emergency: reduction is needed within minutes, usu with parenteral agents Hypertensive Crisis • Accelerated Malignant hypertension: papiloedema, haemorrhage and exudate are associated with markedly elevated BP • Hypertensive Encephalopathy: markedly elevated BP is associated with severe headache and alterations in consciousness Hypertensive Crisis • Aggressive antihypertensive treatment (parenteral) is indicated • Labetalol • Hydralazine • Frusemide • Diazepam (to control seizures) • Careful fluid balance • Oral medications, when crisis under control