Acidosis is a condition of reduced amount of alkaline molecules, respectively of increased acidity (concentration of hydrogen ions) in body fluids, especially blood plasma. There is talk of acidosis when the pH of the arterial blood drops below 7.35, while at the other extreme (alkalosis) the pH rises above 7.45. Acidosis can be respiratory (respiratory), metabolic and mixed (with respiratory and metabolic component). In essence, this is a violation of the alkaline-acid balance in the body and an expression of depletion of the compensatory mechanisms involved in its correction.
Acidosis occurs when the concentration of hydrogen ions in the arterial blood increases above the normal level – 40 nmol / L or pH 7.4. It results from the accumulation of carbon dioxide, acidic metabolic products or a decrease in the concentration of alkaline compounds in the blood. The term acidemia describes a condition of low blood pH, while acidosis is the very process leading to this condition. The level of cellular metabolic activity is affected and at the same time is affected by the pH of body fluids.
In mammals, the normal pH of arterial blood is in the range of 7.35 -7.50, depending on the species. In a healthy person these values are 7.35 – 7.45. Life-compatible human pH variations are between 6.8 and 7.8. Changes in the pH of arterial blood (and subsequently of extracellular fluid) outside these limits lead to irreversible cellular damage. Depending on the mechanism of occurrence, acidosis is divided into metabolic, respiratory and mixed, and according to the pH values - into compensated and decompensated.
Table of Contents
Respiratory acidosis
Respiratory acidosis is the result of an increase in the concentration of carbon dioxide in the blood (hypercapnia) due to hyperventilation. It is most often caused by lung problems, head injuries, medications (anesthetics and sedatives), brain tumor. Pneumothorax, emphysema, chronic bronchitis, asthma, severe pneumonia are also common causes. The condition may also be a compensatory response to chronic metabolic alkalosis.
Diabetic acidosis (ketoacidosis)
A type of metabolic acidosis that occurs as a result of the accumulation of ketone products due to a violation of carbohydrate metabolism. It is observed in uncontrolled diabetes mellitus. It can also occur during starvation. Reflects in a strong shift of glycolysis to lipolysis for energy needs.
Lactic acidosis
A type of metabolic acidosis that occurs when lactic acid (lactate) accumulates in the tissues (tissue hypoxia, certain medications, etc.). Lactic acidosis occurs when cells produce lactic acid faster than the body absorbs it. Key symptoms of lactic acidosis are unusually deep and rapid breathing, vomiting, and abdominal pain. Lactic acidosis can be caused by a number of reasons. It is considered the main symptom in the acute form of diabetes. Lactic acidosis is a rare but severe reaction that occurs after taking metformin (Glucophage), a medicine for type II diabetes.
Metabolic acidosis
This is an increase in the concentration of hydrogen ions and a decrease in the concentration of bicarbonate in body fluids as a result of the accumulation of acids or increased loss of bases from the body. This can happen with diarrhea, kidney disease and more. Metabolic acidosis is characterized by increased production of metabolic acids, usually as a result of disturbances in the mechanism of their excretion by the kidneys.
Renal acidosis is associated with the accumulation of urea and creatinine, as well as residues of metabolic acids from protein metabolism. An increase in the production of other acids may also be the cause of metabolic acidosis. For example, lactic acidosis can have two causes:
- 1) severe (PaO2 <36mm Hg) hypoxemia due to a decrease in the level of diffusing oxygen from the arterial blood to the tissues.
- 2) hypoperfusion (hypovolemic shock) due to inadequate blood oxygen supply to the tissues. The increase in lactate concentration is an indicator of fermentation due to anaerobic metabolism in muscle cells during heavy training. When the oxygen supply is restored, the acidosis quickly disappears.
Acid concentration in poisoning, elevated levels of iron in the blood, chronically decreased production of bicarbonate can lead to metabolic acidosis. It is compensated by the lungs, increasing the exhaled carbon dioxide, and thus changing the buffer balance in the direction of decreasing acidity. This is the result of chemoreceptor stimulation, which in turn enhances alveolar ventilation (known as Kussmaul’s breathing: a specific type of hyperventilation). This, of course, is used with respiratory stress and subsequent risks to the patient.
Mutations in the enzyme V-ATPase ‘a4’ or ‘B1’ isoforms lead to distal renal tubular acidosis – a condition that later turns into metabolic acidosis. Arterial blood gases will show low pH, low blood bicarbonate (HCO3), normal or low CO2 partial pressure. The Henderson-Hasselbalch equation is used to calculate blood pH because blood is a buffer solution. The amount of metabolic acids can be calculated by the variation in the amount of buffer base in the titration process. In hypovolemic shock, for example, approximately 50% of metabolic acids are due to lactic acid (lactate).
Main symptoms of acidosis
They usually accompany the symptoms of another primary defect – respiratory or metabolic. The first signs are fatigue, lethargy, headaches, water retention, weakened immune and muscular systems.
Treatment
The treatment of uncompensated metabolic acidosis is focused on correcting the underlying problem. When metabolic acidosis is severe and can no longer be adequately compensated by the lungs, neutralization of the acidosis by infusion of bicarbonates may be undertaken.
Acidosis – nutrition and sports
Long-term diets with increased protein intake and (almost none) of carbohydrates lead to increased formation of ketones in the blood. Ketones released from adipose tissue bind to acids and disrupt alkaline-acid homeostasis. In this way, less acid can be taken in and removed through the blood – its buffer function is disturbed. The kidneys and liver are severely affected by high acid levels. This is followed by a drop in blood pH below 7.35 and acidosis occurs. It causes the body to break down muscles to neutralize high levels of acids in the blood.
In strength sports and high-intensity training with relatively short breaks, anaerobic exercise leads to the accumulation of lactic acid in the muscles, which slows down the processes of energy production and leads to premature muscle failure. Every experienced bodybuilder strives to avoid such a thing. The reason is that to correct the balance the body will “eat” its own muscle protein, to extract glutamine from it, which will lead to a decrease in acidity.
Therefore, the desire to preserve one’s own muscles must be a reluctance to allow acidosis! Unfortunately, excessive and reckless consumption of large amounts of animal products and at the same time insufficient vegetables and fruits can lead to this problem in completely healthy young people. And bodybuilders often fall into this risk group. Scientific experiments show that an excellent remedy for acidosis and the associated loss of muscle mass is potassium bicarbonate. Sodium bicarbonate (baking soda) was previously thought to be the best remedy, but clinical trials have shown that potassium bicarbonate is significantly more effective.
Of course, plain soda is also able to prevent the problem. You’ve probably heard of some exercisers who dissolve baking soda and drink the solution before a workout. However, high doses of potassium irritate the walls of the stomach. A good alternative is to consume both vegetables and fruits in case of increased intake of animal proteins. Beans, soy and lentils would also be helpful. The acid-base balance of the body is extremely important for its proper functioning and any unreasonable interference in this subtle mechanism can lead to unpleasant health consequences.
