Hypertension (paediatrics)

Hypertension is an increase in blood pressure of more than two standard deviations above the mean'' for the child's age, height and sex. A pressure increased more than two standard deviations above the mean corresponds to a blood pressure higher than the 95th percentile in the population. If the pressure is between the 90th and 95th percentile, or greater than or equal to 120/80 mmHg in adolescents, it is referred to as normal high blood pressure. Percentiles are related not only to age and gender, but also to the child's height. Hypertension is diagnosed based on three different measurements in a non-stressful situation. When "'white coat syndrome'" is suspected (even more common in children than in adults), ambulatory twenty-four-hour blood pressure monitoring is used.

According to etiopathogenesis, hypertension is divided into primary (essential) and secondary (symptomatic – in 75-80% renal etiology). Its prevalence in children varies between 1-10%. In adults, the etiology is essential in the vast majority of cases (95%), in children, on the other hand, secondary hypertension (renovascular, 80%) completely prevailed, only in adolescents the condition approached the adult population. However, due to the increasing prevalence of childhood obesity, this situation is changing.

The level of blood pressure is determined by the filling of the vascular bed (depends on the minute cardiac output) and peripheral vascular resistance (depends on the functional and structural changes of the vascular bed). Arterial hypertension is the result of absolute or relative predominance of pressor, or lack of depressor mechanisms.

Measurements
Several methods are used to measure blood pressure, especially auscultatory, oscillometric and invasive measurements. For non-invasive measurement, a suitable cuff should be used, it should cover 40% of the area of the arm between the olecranon and the acromion, which corresponds to approximately 2/3 of the length of the arm. When measuring with the "auscultation method", the stethoscope should not touch the cuff. When reading the diastolic pressure, the 5th Korotkov phenomenon (disappearance of murmurs) appears in some younger children at values approaching zero, therefore the 4th Korotkov phenomenon (weakening of murmurs) is then used.

Causes

 * Primary essential hypertension

The occurrence of essential hypertension is associated with the occurrence of obesity.


 * Renal


 * renoparenchymatous: vesicoureteral reflux, glomerulonephritis, dysplastic kidneys, polycystic kidneys, hemolytic-uremic syndrome, pyelonephritis, obstructive nephropathy, kidney tumors producing renin, hydronephrosis, kidney injury, Wilms tumor, systemic lupus erythematosus;
 * renovascular: renal artery stenosis (fibromuscular artery dysplasia), renal vein thrombosis.


 * Cardiac/Vascular


 * coarctation of the aorta, hypertensive form polyglobulia, persistent ductus arteriosus, vasculitis.


 * Endocrine


 * Pheochromocytoma, Cushing's syndrome, corticoids, estrogens, sympathomimetics, hyperthyroidism or hypothyroidism, primary hyperaldosteronism, hypertensive form of adrenogenital syndrome, hyperparathyroidism, primary reninism.


 * Some CNS diseases


 * inflammations, tumors, intracranial hypertension syndrome, poliomyelitis, polyradiculoneuritis.


 * Intoxication with substances and drugs


 * amphetamine, LSD, cocaine, ecstasy;
 * mercury ,