Acid-base balance blood values

The pH value is kept constant by buffer systems that cushion minor disturbances in the acid-base balance (C). In the longer term, the decisive aspect is maintaining a balanced equilibrium between H" production and uptake and H" release. If the blood s buffering capacity is not suf cient, or if the acid-base balance is not in equilibrium—e.g., in kidney disease or during hypoventilation or hyperventilation-shifts in the plasma pH value can occur. A reduction by more than 0.03 units is known as acidosis, and an increase is called alkalosis. 

It is not yet clear which estimates of the ratio between the levels of protein and of carbohydrate metabolism during hypoxia should be regarded as reliable. It seems likely that the increase in respiratory quotient in freshwater fish to values of 2.5-2.8, as found by Mohamed and Kutty (1983a, 1986), indicates a predominance of protein expenditure over that of carbohydrate. A hypoxic environment shifts the acid-base balance of the fish towards acidosis (Kotsar, 1976), thereby inducing the redistribution of electrolytes, alteration of ion exchange and the activity of Na+-K+-Mg2+-ATPases and alkaline phosphatases. It also leads to an increased level of C02 in the blood, which enhances the bicarbonate buffer system (Kotsar, 1976). In section 2.1, we... 

Since the recognition of the importance of the study of the acid-base balance, the interest in these values has gradually increased. It was, however, soon recognized that conventional pH electrodes were not suited for the determination of blood or plasma pH due to the prolonged contact of the sample with air. 

If any two of the variables are known, the third can always be calculated. Indeed, blood gas analyzers (Fig. I) are programmed to provide this information which is printed out on the report I orni and usually includes the measured POi us well. There are a multitude of other calculated values oit some blood gas analyzer print outs, such as base excess and standard bicarbonate. These nitty be mostly disregarded in the routine assessment of a patient s acid-base balance. 

Chapter 6). Prolonged or excessive losses of fluid via the GI tract will affect packed cell volume (hematocrit), plasma total protein, albumin, electrolytes, acid-base balance, and osmolality values as the circulating blood volume adjusts to the fluid loss. Excessive and prolonged salivation may also cause electrolyte perturbations, but to a much smaller extent. Hypo- or hypernatremia may occur depending on the proportional losses of electrolyte to water these electrolyte changes are also reflected by plasma osmolality. There may be significant differences between the measured and calculated plasma osmolality in the presence of hyperlipidemia and hyperproteinemia. 

As a metabolic organ, the K. is responsible for the constancy of the acid-base balance of the body. The normal pH of the blood is 7.4, and it is important that this value is not increased (see Alkalosis) or decreased (see Acidosis). The K. contains amine oxidases and glutaminase, which catalyse the production of free ammonia. In acidosis these reactions are brought into play and excess H ions are consumed by formation of NH In addition to the natural secretory processes foreign substances such as pharma-... 

The regulation of the acid-base balance involves the transfer of ions to yield either new base or new acid. When the pH of the blood drops below normal values, the total concentration of free proton donors (acids) increases whereas that of free proton acceptors (bases) decreases. In the body fluids Na, , Ca, ... 

Normalization of laboratory parameters must be guaranteed (i.) regulation of serum electrolytes, acid-base equilibrium and blood sugar values, (2.) substitution of zinc, and (2.) compensation of hypovolaemia. Metabolic alkalosis should not be balanced, since it is important for the urea cycle. 

A buffer solution is a solution of(l)a weak acid or a weak base and (2) its salt both components must be present. The solution has the ability to resist changes in pH upon the addition of small amounts of either acid or base. Buffers are very important to chemical and biological systems. The pH in the human body varies greatly from one fluid to another for example, the pH of blood is about 7.4, whereas the gastric juice in our stomachs has a pH of about 1.5. These pH values, which are crucial for proper enzyme function and the balance of osmotic pressure, are maintained by buffers in most cases. 

---