SYSTOLIC (a) AND DIASTOLIC (b) PRESSURE in children of different ages.
Blood pressure- pressure exerted by blood on the walls of the chambers of the heart and blood vessels. The cardiovascular system and the promotion of blood in the cardiovascular system are provided as a result of contraction of the musculature of the ventricles, as well as contraction of the skeletal muscles surrounding the blood vessels, pulsations of the arteries transmitted to the veins located nearby and periodically contracting. There are K. d. Arterial, venous and capillary.
Normal values of the arterial pressure in children are calculated in mm Hg using the formula of V. I. Molchanov for max, pressure: 80 + twice the number of years; the minimum, as in adults, is V3 — V2 maximum. In de-accelerators, 90 mmHg is taken as the initial figure. st. (or 29,997 kPa). The younger the child, the lower the blood pressure. In newborns and children of the 1st year of life max. Blood pressure is less than 80. With age, blood pressure rises, especially noticeable in the 1st year of life; By the age of 14–15, KD figures correspond to those in adults.
Increased blood pressure in children can occur with physical. load and excitement, but more often is a symptom of glomerulone-free, nodular periarteritis, vegetation dystonia. Decrease in blood pressure is observed with toxico-infectious shock and collapse, serum sickness, heart failure (see Circulatory failure), myocarditis. Venous pressure is the lowest in the vascular system and depends on the position of the body.
The closer the veins are to the heart, the lower the pressure in them (10-12 mmHg). Venous pressure fluctuates during inhalation and exhalation phases, sometimes even becomes negative. The magnitude of capillary pressure in arterial capillaries is quite constant and amounts to 30-50 mm Hg. st. The pressure in the venous capillaries without load and in the horizontal position of the body is 15-25 mm Hg. st. The indices K. in the SI system are expressed in kilopascals (kPa). To convert the value of K. d. (In mm Hg. Art.) To the SI system, it is necessary to multiply it by 0.1333.