MSSC_Childhood Hypertension.pdf

Childhood Hypertension Introduction • Hypertension in children is becoming more observed over the past years • It is known to be a significant cause of morbidity and mortality • Normative data including percentile curves exist to diagnose and categorize hypertension in children Definition • Chil...

Childhood Hypertension Introduction • Hypertension in children is becoming more observed over the past years • It is known to be a significant cause of morbidity and mortality • Normative data including percentile curves exist to diagnose and categorize hypertension in children Definition • Childhood hypertension is defined as systolic and/or diastolic pressure greater than the 95th percentile for age or gender (and height) on at least three occassions Classification of BP BP Classification • Normal • *Prehypertension Levels < 90th percentile 90th-95th percentile • Stage 1 hypertension 95th-99th percentile • Stage 2 hypertension ≥ 5mmHg + 99thp.value Pathophysiology BP is dependent on a balance b/w CO and VR • CO is affected by: baroreceptors, ECF volume, mineralocorticoids, angiotensin • VR is affected by: pressors (angiotensin II, Ca, catecholamines, Sympathetic NS • depressors- kinins, entholelial relaxing factors, prostaglandin E2 Causes • Hypertension may be primary or secondary • The younger the child and the higher the BP the greater the chances of it being secondary • More than 90% of secondary hypertension in non-obese children is caused by: renal parenchymal disease, renal artery disease, and coarctation of the aorta • Other causes include endocrine, neurogenic, drugs and chemicals Causes Renal parenchymal disease • Acute or chronic Glomerulonephritis • Acute or chronic pyelonephritis • Obstructive uropathies • HUS • Renal damage from nephrotoxins, trauma, radiation Causes Renovascular disease *Renal artery disorders • stenosis • polyarteritis • thrombosis *Renal vein thrombosis Causes Cardiovascular- conditions with large stroke volume • PDA • Aortic insufficiency • Systemic AV fistula • Complete heart block Causes Endocrine • Hyperthyroidism • Excessive catecholamine levels • Adrenal dysfunction • Hyperaldosteronism • Hyperparathyroidism Causes Neurogenic • Increased intracranial pressure • Poliomyelitis • Guillain-Barre syndrome Causes Drugs and chemicals • Sympathomimetic drugs • Amphetamines • Steroids • NSAIDS • Oral contraceptives • Heavy metal poisoning • Cocaine Causes Miscellaneous • Hypervolemia • Hypernatremia • Steven-Johnson syndrome • Bronchopulmonary dysplasia Diagnosis • Relies on accurate BP measurement and comparison with acceptable standards • Exclude the phenomenon of ‘white coat hypertension’ • Careful history, PE and laboratory tests are very useful History • • • • • • • Neonatal Of palpitations, headache, excessive sweating Of obstructive uropathies, UTI, trauma Cardiovascular: CoA or its surgery Medications Family history of essential hypertension, IHD Familial or hereditary renal disease Physical Examination • Accurate BP measurement • Evidence of delayed growth, bounding pulse, weak or absent femoral pulses, tenderness over the kidney • Weight and BMI Laboratory investigations Initial tests geared towards identifying the common causes • Urinalysis • Urine culture • Electrolytes, urea and creatinine • ECG • CXR • Echo Treatment Essential hypertension * Non pharmacologic intervention • Counseling on weight reduction, • Low-salt, potassium-rich foods, • Avoidance of smoking and oral contraceptives Pharmacologic treatment Indications for drug treatment include: • Severe symptomatic hypertension • Significant secondary hypertension • Target organ damage • Family history of early complications of HBP • Diabetes • Dyslipidemia and other CA risk factors • Persistent hypertension despite non pharmacologic measures Treatment Treatment goals • For children with uncomplicated hypertension wthout end organ damage: reduction of BP to < 95th percentile • For children with chronic renal disease, diabetes, target organ damage: reduction to < 90th percentile Classes of antihypertensive drugs • Diuretics • Adrenergic inhibitors • ACE inhibitors eg. Captipril • ARBs • Calcium channel blockers eg. Verapamil • Direct-acting vasodilators Treatment of secondary hypertension • Aimed at removing the cause • Cardiovascular causes • Renal parenchymal disease • Tumours Hypertensive crises There is a rapidly rising BP or a high BP associated with neurological manifestations, heart failure or pulmonary oedema. It is divided into: • Hypertensive urgency • Hypertensive emergency • Accelerated malignant hypertension • Hypertensive encephalopathy Hypertensive crises • Hypertensive urgency: reduction of BP is needed within hours • Hypertensive emergency: immediate reduction is needed (within minutes) • Accelerated malignant hypertension: papilloedema, haemorrhage and exudate are associated with a markedly ↑ BP • Hypertensive encephalopathy: markedly raised BP with headache and altered consciousness