Acid-base equilibrium (synonym: acid-base balance, acid-base balance, balance of acids and the bases) — the relative constancy of concentration of hydrogen ions in internal environments of an organism providing full value of the metabolic processes proceeding in cells and fabrics.
In practice of sports medicine the control of efficiency of training process is exercised on the basis of assessment of a complex of parameters among which a certain part is assigned to indicators of the acid-base state (ABS). These indicators – objective criteria of readiness of athletes, they can be used for identification of level of power supply of muscle performance, a functional condition of cardiovascular and respiratory systems, adaptation to sports loading.
Long work in the glycoclastic mode, anemia, a lack of bicarbonates can be the reasons of disturbances of BRAIDS and ionic balance in an organism at physical activity.
The buffer tank of blood izmenenyatsya as a result, there is an accumulation of lactic acid (La), shift rn blood in the acid party (acidosis). The crucial role is played by the speed of increase in concentration of lactic acid. Sharp decrease in physical effeciency of the athlete becomes a result of delay of utilization of La.
For identification and control can be used: La, pH, Hb in blood. These indicators – objective criteria of readiness of the athlete and his adaptation to sports loading.
Necessary correction has to be directed to increase in a buffer tank of blood, alkalization, decrease in level of lactic acid, maintaining water-salt balance.
Acid-base equilibrium at children
Range of physiological fluctuations rn is slightly wider than extracellular liquid at children, than at adults. Big, than at adults, respiration rate at newborns and children of early age explains lower sizes rSO2 at them in blood and negative sizes of surplus of the bases (BE) since actually the deficit of the bases in blood because of continuous formation of acid equivalents and their insufficient removal by kidneys is absent. It defines tendency of children, especially newborn, to acidosis. Capacity of buffer systems of blood at children reaches the sizes characteristic of adults, only by the pubertal period.
In the course of patrimonial activity in blood of mother there is an accumulation of lactic acid, at the same time concentration of ions of H+ and in fruit blood increases; in toxicosis of pregnant women, premature placental detachment, crossclamping of umbilical veins the acidulation of blood of a fruit becomes pathological. At an adverse course of childbirth the placenta begins to absorb bigger amount of oxygen, than at their physiological course, the fruit hypoxia develops, glycolysis and as result, such amount of lactic acid with which kidneys cannot cope collects is stimulated in its fabrics. The metabolic acidosis and clinical symptomatology respectively on weight develop: wrong, sometimes "big" breath, lack of reaction of the newborn to external irritants, damage of a myocardium, decrease in amplitude of respiratory movements. At rn 6.75 there comes the limit of reversibility of pathophysiological reactions, at rn 6.6 elektroentsefalografichesky potentials disappear, at rn 6.4 there are changes not compatible to life.
Physiological "boundary" acidosis of the newborns who were born with normal body weight disappears on third day; at the children who were born with low body weight, this period can be more long.
At premature children the metabolic acidosis develops much more often than at full-term therefore over 4 g are not recommended to increase the protein content (source of acid equivalents) in a diet of premature children by 1 kg of body weight and to appoint acid milk mixes.
Acid-base equilibrium at children of early age is easily broken in connection with frequent diseases of respiratory organs or in anemia. Its regulation becomes steadier at healthy children by the end of the first year of life.