Metabolic alkalosis

Introduction Metabolic alkalosis (alkali) is caused by a decrease in non-volatile acids or an increase in alkali in extracellular fluid. Its main feature is an increase in plasma HCO3- concentration and a compensatory increase in PaCO2. It can be present alone or in combination with respiratory acidosis. Its main compensatory mechanisms are respiratory CO2 retention and renal excretion of bicarbonate with retention of H+. Symptoms of alkaloids include numbness, tingling, wrist and ankle and arrhythmia. But often covered by the primary disease. With low calcium, hand and foot convulsions may occur; with low potassium, polyuria, polydipsia and paralysis may occur; with low volume, postural vertigo and muscle weakness may occur. In severe cases, there may be confusion, unresponsiveness, and even paralysis.

Cause

Gastric juice loss

Vomiting, long-term gastric aspiration, pyloric obstruction, and surgical anesthesia can lose a lot of gastric juice.

2. Lack of potassium.

3. Extracellular fluid Cl- reduction

If the intake is reduced, or due to loss of gastric juice, or due to the use of furosemide, thiazide diuretics or renal ion channel mutations such as Bartter syndrome or Gitleman syndrome, a large amount of Cl- is lost through the kidney, or due to congenital intestinal mucosal cells Absorption of Cl- functional defects, etc., can reduce the extracellular fluid Cl-.

4. Bicarbonate accumulation

(1) Long-term use of a large amount of alkaline drugs in the treatment of gastric ulcer disease, so that the gastric acid is reduced or disappeared, so that the bicarbonate in the intestinal juice is absorbed into the blood without being neutralized, and the amount of HCO3- in the blood is increased, thereby causing alkali Poisoned.

(2) excessive intake of organic acid salts or oral injection of lactate, citrate (large amount of blood transfusion), excessive acetate, they are converted into CO2 and H2O in the liver, and form bicarbonate, so that the blood The content of HCO3- is greatly increased, contributing to alkalosis.

(3) After cardiopulmonary resuscitation, a large amount of sodium bicarbonate is used for resuscitation, lactate is metabolized, and the consumed HCO3- can be recovered. As a result, the HCO3- in the blood is as high as 60-70 mmol/L, and the pH value is 7.90. . In addition, in the case of renal failure, metabolic alkalosis can also occur if too much sodium bicarbonate is used.

5. Too much mineralocorticoid

Including aldosteronism, Cushing's syndrome and so on.

an examination

1. Blood pH and HCO3- increase, blood potassium, blood chlorine decreased.

2. Clinically, metabolic sputum poisoning can be diagnosed by X-ray or gastroscopy if it is caused by pyloric obstruction.

3. Patients with suspected mineralocorticoids can check the levels of aldosterone and cortisol.

Differential diagnosis

diagnosis

According to the history, physical signs and blood gas analysis of AB, SB, BB, BE, blood PCO2, blood pH values are increased, the diagnosis of metabolic alkalosis can be obtained. The formula for compensating for metabolic acidosis is:

PCO2 = 0.7 × [HCO3] ± 5.

PCO2 = 40 + 0.7 × [HCO3] ± 5.

1. If the measured PCO2 40 + 0.7 × [HCO3] ± 5, indicating that metabolic alkalosis has reached the maximum compensation.

2. If the measured PCO2<40+0.7×[HCO3]±5, it may be metabolic alkalosis with respiratory alkalosis, or mild metabolic alkalosis, or the onset time is less than 12~24h. , has not reached the maximum compensation, or because of the factors that stimulate breathing.

3. If the measured PCO2>40+0.7×[HCO3]±5, it may be metabolic alkalosis combined with respiratory acidosis, or metabolic alkalosis with metabolic acidosis, or excessively compensated metabolic base. Poisoned.

Differential diagnosis

The disease should be differentiated from metabolic acidosis, respiratory acidosis, and respiratory alkalosis.

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