Acidosis (overacidification) – causes, symptoms & therapy

Acidosis is a disorder of the acid-base balance characterized by a drop in arterial pH below 7.36. Normally, the pH value in the blood is between 7.36 and 7.44.

The organism’s buffer systems balance the acid-base balance via respiration (respiratory compensation) or kidney excretion (renal compensation) when acids are supplied to the body or when they occur in excess as metabolic products. In the case of acidosis, this self-regulating mechanism is disrupted, resulting in overacidification of the organism.

causes

Acidosis can be differentiated according to metabolic (metabolism-related) and respiratory (breathing-related) causes.Respiratory acidosis is characterized by an increase in arterial carbon dioxide partial pressure and may be due to impaired breathing activity (hypoventilation) that causes reduced excretion of acidic carbon dioxide through respiration.

Hypoventilation can be caused by lung dysfunction such as bronchial asthma, pulmonary fibrosis , or pulmonary emphysema . Rib fractures and neuromuscular diseases can also limit the body’s own respiratory compensation capacity and lead to hyperacidity.

On the one hand, metabolic acidosis can be accompanied by an increased intake or formation of acids (additional acidosis). Causes of additive acidosis include diabetes mellitus (diabetic ketoacidosis), excessive muscle work (lactic acidosis), shock, or poisoning from methanol, glycol, or salicylates.

On the other hand, metabolic hyperacidity can be due to renal insufficiency, which limits the excretion of acidic metabolic products via the kidneys (retention acidosis). Furthermore, diarrhea or diuretics (water pills) can cause increased excretion of bases and thus acidosis (subtraction acidosis).

When to the doctor?

Acidosis (excessive acidity) brings numerous dangerous symptoms with it. Acidosis usually results in shortness of breath and blue-colored lips. In addition, sufferers are weakened and feel disoriented. Acidosis is also noticeable through increased water excretion.

Depending on the form of hyperacidity, those affected may also notice increased breathing. Breath often smells of acetone. Acute acidosis usually also affects the heart and blood vessels. With these signs, it is always advisable to consult a doctor. Hyperacidity causes lower blood pressure, cardiac arrhythmia and severe unconsciousness, especially later on. In the latter case, an ambulance must be called immediately.

Seemingly insignificant symptoms such as fatigue, susceptibility to infection and severe headaches can also indicate acidosis. In some cases, acidosis causes muscle pain, muscle cramps, and unusual fatigue. Hyperacidity is usually accompanied by heartburn . A medical professional should always be consulted for all symptoms.

symptoms and course

Respiratory acidosis is usually accompanied by hypoxia (reduced oxygen supply to the organism), which is indicated by shortness of breath and cyanosis ( blue discoloration of the lips ). Since an attempt is made to compensate for the excessive acid concentration via renal compensation, increased water excretion can be observed.

In the case of metabolic acidosis, deepened (Kussmaul respiration) and accelerated breathing (hyperventilation) are symptomatic, since the acid-base imbalance is to be compensated for by increased exhalation of carbon dioxide. If diabetes mellitus is the underlying cause of metabolic acidosis, the patient’s breath will have the characteristic odor of acetone.

In the further course, hyperacidity leads to tachycardia , drop in blood pressure and severe disturbances of consciousness . If left untreated, acidosis can cause osteoporosis (decrease in bone substance and structure), coronary heart disease , rheumatoid arthritis and arteriosclerosis in the long term .

Diagnose

Acute acidosis is diagnosed with a blood gas analysis, which measures arterial pH, blood oxygen, and carbon dioxide levels. The bicarbonate values ​​and the carbon dioxide partial pressure (pCO2 value) are used for differential diagnostics (distinguishing between metabolic and respiratory acidification). An elevated pCO2 value indicates respiratory acidosis and a reduced bicarbonate value indicates metabolic acidosis. Compensated hyperacidity is present when the arterial pH value is in the normal range, but the other values ​​of the blood gas analysis indicate a disruption in the buffer capacity. To diagnose chronic acidosis, the pH of the urine is determined using a test strip.

treatment and therapy

In the case of acidosis, therapeutic measures are aimed on the one hand at compensating for the acute excess of acid (symptomatic therapy) and on the other hand at treating the underlying causes or underlying diseases (e.g. causal treatment of the derailed diabetes mellitus ). For respiratory acidosis, therapy focuses on eliminating the causes of the breathing disorder and increasing ventilation (breathing).

Controlled ventilation may be required in acute respiratory acidosis.

In the presence of respiratory hyperacidity, which is due to chronic ventilation disorders, bronchospasmolytics, which are used to widen the bronchi, and/or secretolysis therapy, which serves to remove tough bronchial mucus, are possible.If there is acute metabolic acidosis (overacidification due to insufficient CO2 exhalation), buffer substances (sodium bicarbonate solution, Tris buffer) are infused (by infusion) to partially correct the overacidification, which increase the body’s buffering capacity. If the correction is too strong, however, there is a risk of alkalosis (increase in the pH value in the blood).

In the case of metabolic hyperacidity resulting from diabetes mellitus (diabetic ketoacidosis), bicarbonates are often avoided and an attempt is made to compensate for the acid-base imbalance as part of insulin therapy.

If chronic renal failure is the underlying cause of metabolic acidosis, dialysis may be necessary.

In the presence of latent metabolic acidosis, in which the arterial pH is in the slightly acidic normal range, bicarbonate substitution (bicarbonate infusion) is usually recommended, which allows more CO2 to be delivered through the lungs.

In addition, if hyperacidity is present, the fluid intake should be increased and if those affected have latent acidosis, a change in diet should be considered.

prevention

Acidosis can be prevented if underlying diseases that can lead to hyperacidity, such as bronchial asthma and other pulmonary dysfunctions as well as diabetes mellitus and chronic renal insufficiency, are diagnosed early and treated consistently. A balanced diet, adequate exercise and fluid intake, and avoiding excessive alcohol and nicotine consumption can also prevent acidosis.