Respiratory acidosis

Definition

Respiratory acidosis is a shift of the pH value in the blood to the acidic range. The normal blood pH value fluctuates between 7.38-7.45. If respiratory acidosis is present, the pH value decreases.

As the name suggests, the presence of respiratory acidosis is caused by a respiratory disorder. The patient hypoventilats, which means that he breathes less than normal. However, balanced breathing is essential to maintain the physiological pH of the blood. It is therefore obvious that if breathing is disturbed, the pH value also changes pathologically.

Causes

Respiratory acidosis develops due to hypoventilation, a situation in which the patient breathes too little. This means that the patient does not breathe out enough CO2, which is the main acidity in the blood. At the same time, however, there is another problem: Due to insufficient respiration, the patient in turn breathes too little oxygen.

The reasons for the presence of hypoventilation vary, the most common being the following: Lung diseases that hinder breathing, such as asthma or bronchitis, damage to the respiratory center, respiratory global insufficiency.

  • Lung diseases that impede breathing, such as asthma or bronchitis
  • The damage of the respiratory center,
  • Respiratory global insufficiency.

COPD (chronic obstructive pulmonary disease) is a chronic lung disease. It is characterized by a narrowing of the airways, which hinders breathing out.

The main symptoms of this disease are shortness of breath, coughing and sputum. The two most common causes are chronic cigarette smoking and a genetic defect, the so-called Alpha-1-Antitrypsin Deficiency. In both cases there is a pathological change in the lung tissue: The elastic fibers of the lung decrease, the tissue “hardens” increasingly.

This results in emphysema, i.e. small air sacs in the lungs that over-inflate due to the lack of elastic fibers and do not return to their original form. They therefore no longer take part in the gas exchange. Since in COPD, as already mentioned, exhalation is not physiological, i.e. not as in a healthy lung, more CO2 remains in the lungs than it should, resulting in respiratory acidosis.

Since the high CO2 level in the blood causes an increased respiratory drive, patients breathe more and overexert themselves. To relieve them, they are ventilated in the clinic. As a result, patients have more O2 at their disposal and also breathe CO2 more easily, which means they have to take fewer breaths. In addition, in the event of an acute outbreak, patients are given medication that dilates the bronchial tubes. This also helps the patients to breathe sufficiently and physiologically.