Metabolic alkalosis, or non-respiratory alkalosis, is a disturbance of the acid-base balance in which there is an increase in pH. Metabolic alkalosis has serious consequences for the human body. What are the first symptoms? How to proceed in the fight against metabolic alkalosis?

Metabolic alkalosis( non-respiratory alkalosis , alkalosis, Latinalcalosis ) is associated with an increase in blood pH above 7.45. When metabolic (non-respiratory) alkalosis occurs in the body, the concentration of bicarbonate ions (or other bases) increases, or the loss of hydrogen ions occurs. This is a slightly different mechanism than in the case of respiratory alkalosis, where the cause of the acid-base imbalance is hyperventilation.

It should be remembered here that the correct pH values ​​are 7.35-7.45, and a drop in pH below 7.35 indicates acidosis.

Metabolic Alkalosis: Causes

There is no single cause of metabolic alkalosis. There are three most common situations in which alkalosis occurs.

The first is hypokalemia. It is an electrolyte disturbance in which the amount of potassium ions in the serum is less than 3.8 mmol / L.

Hypokalemia can occur as a result of the use of diuretics - diuretics, laxatives, or chronic use of glucocorticosteroids.

An important cause may also be the excessive loss of hydrogen or chloride ions, e.g. through the gastrointestinal tract - due to vomiting, gastric suctioning, or congenital chlorine diarrhea.

The loss of ions that cause metabolic alkalosis can occur in the urine, due to the use of diuretics, but also through the skin for people suffering from cystic fibrosis.

The last most common underlying cause of metabolic alkalosis is an overabundance of bases or potential bases such as sodium bicarbonate, citrate, or sodium lactate.

In post-hypercapnic alkalosis, hypercapnia, i.e. increased partial pressure of carbon dioxide in the blood, is too quickly corrected, with a compensatingly increased concentration of bicarbonates.

Metabolic Alkalosis: Symptoms

The symptoms of metabolic alkalosis depend on the underlying cause.

Hypokalemia is usually associated witharrhythmias, which show the following picture on ECG, depending on the severity of the hypokalaemia:

1. potassium ion concentration<3,5 mmol/l

  • decrease T wave amplitude
  • increase in the amplitude and width of the U waves
  • lowering ST segments

2. in more advanced hypokalemia

  • extension of PQ intervals
  • broadening the QRS complexes
  • ventricular premature beats

Zasadowica, on the other hand, manifests itself with the symptoms of tetany and tetany equivalents.

Tetany is mainly characterized by numbness of the hands and symmetrical tonic contractions of the muscles of the hands, then of the forearms and arms, and of the face (spasm of the eyelids, "carp mouth") of the chest and lower limbs. Importantly, the patient remains aware.

Latent tetany is revealed primarily by two characteristic symptoms. The Chvostek symptom is manifested by the contraction of the facial muscles after hitting the facial nerve with a hammer, and the Trousseau symptom consists in clenching the hand in the so-called obstetrician's hand.

An important signal is the possibility of inducing a tetanic attack through hyperventilation.

Equally dangerous symptoms of alkalosis are tetany equivalents. It causes many ailments, including eyelid cramps, photophobia, double vision, laryngeal muscle spasms, bronchospasm, asthma attacks.

There may be spasms of the coronary arteries leading to angina, spasms of the abdominal and cerebral arteries manifested by migraines, temporary loss of consciousness.

Metabolic alkalosis: diagnosis

The most important test to detect acid-base imbalance is arterial blood gas measurement. Arterial blood is collected, most often from the radial or femoral artery.

The essential criteria for the diagnosis of metabolic alkalosis are a pH value above 7.45, an increased concentration of bicarbonate and an increase in CO2 partial pressure as a symptom of compensatory mechanisms.

With balanced metabolic alkalosis, i.e. when the pH value is correct, it should be differentiated from compensated respiratory acidosis.

Metabolic Alkalosis: Treatment

Treatment of metabolic alkalosis is primarily causal. The factor causing the disturbances should be eliminated.

If the problem with metabolic alkalosis is hypokalemia, you need to correct the potassium deficiency. It should be given in the form of KCl. The method of supplementing with potassium depends on the severity and the presence of symptoms of hypokalemia:

  1. K + ≥ 2.5 mmol / L, no symptoms - orally20-30 mmol K + 2-4 times a day
  2. K +<2,5 mmol/l lub z występującymi objawami - trzeba rozpocząć od dożylnego wlewu maksymalnie 20 mmol K+/h

Metabolic alkalosis is seriously life-threatening, do not ignore its first symptoms.

Prevention and rational nutrition may turn out to be a way to avoid acid-base disorders, including metabolic alkalosis.

Category:

Cardiology