The formula for sodium bicarbonate rehydration is: volume of 5% sodium bicarbonate solution (ml) = (number of HCO₃ˉ mmol to be raised) × body weight (kg) × 0.7 ml. The molecular weight of sodium bicarbonate is 84, and 1 mmol of sodium bicarbonate is equal to 1.7 ml of 5% sodium bicarbonate; the formula for supplementing HCO₃ˉ = (number of HCO₃ˉ mmol to be raised) × body weight (kg ) × 0.4, so the volume of 5% sodium bicarbonate solution (ml) = (number of HCO₃ˉ mmol to be raised) × body weight (kg ) × 0.4 × 1.7. The principle of alkali supplementation is to prefer acid to alkali, and the indications for alkali supplementation should be strictly grasped in the treatment of metabolic acidosis, and half the amount of the drug should be given first.