Causes and management of metabolic acidosis

The article was written by MSc Phan Van Phong - Emergency Doctor - Emergency Department - Vinmec Central Park International General Hospital

Metabolic acidosis is a decrease in [HCO3-], reflecting either the retention of fixed acids or the loss of alkalinity. The compensatory response is hyperventilation leading to a decrease in PaCO2.

1.1. Acidosis without anion gap (hyperchloremic hyperchloremia) Classified by serum potassium
Type with high or normal blood potassium: + Decreased secretion of Aldosterone .
+ Intravenous type renal tubular acidosis.
+ Moderate renal failure (glomerular filtration rate > 20 ml/min).
+ Add HCl and then reduce CO2.
Low serum potassium: + Loss through the stomach, intestines due to bicarbonate loss (diarrhea, branching ureter, biliary or pancreatic fistula).
+ Carbonic Anhydrase Inhibitors.
+ Acidosis due to distal and proximal tubular disease.
+ Decreased acid secretion in the renal tubules.
1.2. Anion gap acidosis (anion gap) Ketosis due to hyperglycemia. Lactic acidosis: consequences of shock, acute pancreatitis, poisoning, acute liver failure ... Poisoning with drugs (Methanol Salicylate, Ethylene glycol, Paraaldehyde). Renal tubular acidosis.

2.1. Principles of management Treating the cause, treating acidosis must pay attention to the time of occurrence of acid-base balance disorders.
For example, if ketoacidosis is usually of short duration, maximal respiratory compensation is safest. In contrast, for cases of chronic acidosis (such as kidney failure...) the treatment aims to restore the strong ion difference (Strong ion diffirence - SID).
2.2. Treatment Measures Sodium Bicarbonate Using sodium bicarbonate is the simplest and most effective.
If mild, just give 1g of sodium bicarbonate with 12 mmol of sodium bicarbonate. pH < 7.20 need to compensate for intravenous bicarbonate is calculated by the formula:
[HCO3] deficiency = PKg x (0.4) x ([ HCO3 ]need to achieve - [ HCO3 ] measured)
Half of the deficit can be compensated in 3 to 4 hours in the absence of severe heart failure. Sodium bicarbonate solutions were used 1.4%, 4.2% and 8.4%.
Particularly in diabetic ketoacidosis should not be compensated with Bicarbonate, just enough fluid infusion to eliminate Betahydroxybutyric Acid and correct and timely insulin is enough.
THAM is an H+ ion acceptor indicated when hypernatremic metabolic acidosis is contraindicated with sodium bicarbonate. However, it can cause depression of the respiratory center, hypoglycemia, and severe liver necrosis.
Treatment of metabolic acidosis without increasing anion gap (hyperchloremia).
Extra-renal dialysis In case of renal failure but with strong catabolism causing blood urea, creatinine or potassium to increase rapidly and not eliminate acid radicals, dialysis is indicated.

Vinmec International General Hospital is one of the hospitals that not only ensures professional quality with a team of leading medical professionals, a system of modern equipment and technology. The hospital provides comprehensive and professional medical examination, consultation and treatment services, with a civilized, polite, safe and sterile medical examination and treatment space. Customers when choosing to perform tests here can be completely assured of the accuracy of test results.