How do you treat metabolic acidosis?

Treatment of Metabolic Acidosis with Bicarbonate of 18.8 mmol/L

For a bicarbonate level of 18.8 mmol/L, pharmacological treatment is generally not recommended unless there are clinical implications or symptoms of acidosis, as this level is just above the threshold (18 mmol/L) that would warrant intervention according to current guidelines. 1

Assessment of Metabolic Acidosis

When evaluating a patient with a bicarbonate level of 18.8 mmol/L:

• Determine if this represents true metabolic acidosis by checking:

  • Arterial or venous pH (acidemia if pH < 7.3)
  • Anion gap to differentiate between high anion gap and normal anion gap acidosis
  • Clinical symptoms or complications related to the acidosis

• Identify the underlying cause:

  • Chronic kidney disease (CKD)
  • Diabetic ketoacidosis (DKA)
  • Lactic acidosis
  • Diarrhea or gastrointestinal bicarbonate losses
  • Renal tubular acidosis
  • Drug or toxin ingestion

Treatment Algorithm

For Bicarbonate Level 18.8 mmol/L:

1. Monitor and address the underlying cause

   • This level is just above the threshold (18 mmol/L) that would typically warrant pharmacological intervention 1
   • Focus on treating the primary condition causing the mild acidosis

2. Consider treatment only if:

   • Clinical symptoms are present
   • Patient has CKD with risk factors for progression
   • There is evidence of protein catabolism, bone disease, or other complications

3. If treatment is deemed necessary:

   • Sodium bicarbonate is the first-line medication for metabolic acidosis 2, 3
   • Dosage: 1-2 mEq/kg IV given slowly for acute situations 1
   • For chronic management: oral sodium bicarbonate supplements titrated to achieve target bicarbonate levels

For Bicarbonate Level < 18 mmol/L:

1. Initiate pharmacological treatment 1

   • Sodium bicarbonate (oral or IV depending on severity)
   • Target: Increase bicarbonate levels toward but not exceeding the normal range

2. Dosing considerations:

   • IV administration: 1-2 mEq/kg given slowly 2
   • Oral administration: Start with 650 mg to 1300 mg three times daily, titrate as needed

3. Monitor closely:

   • Serum electrolytes every 2-4 hours initially
   • Blood pressure
   • Fluid status
   • Serum potassium

Special Considerations

For Diabetic Ketoacidosis:

• Insulin therapy is the primary treatment, not bicarbonate 1
• Bicarbonate therapy is generally reserved for severe acidosis (pH < 6.9) 1
• Focus on fluid resuscitation and insulin administration

For Chronic Kidney Disease:

• Consider treatment when bicarbonate < 18 mmol/L 1
• Target bicarbonate levels toward but not exceeding normal range
• Monitor for adverse effects including fluid overload, hypertension, and hypocalcemia

For Lactic Acidosis:

• Focus on treating the underlying cause (improving tissue perfusion)
• Bicarbonate administration has not shown to reduce morbidity or mortality 4

Monitoring During Treatment

• Serum electrolytes (Na, K, Cl, HCO3) every 2-4 hours initially
• Venous pH and anion gap to monitor resolution of acidosis
• Blood pressure and fluid status
• Signs of clinical improvement or deterioration

Potential Complications of Treatment

• Volume overload
• Exacerbation of hypertension
• Hypocalcemia
• Paradoxical intracellular acidosis
• Hypernatremia
• Facilitation of vascular calcifications in CKD patients

Conclusion

For a bicarbonate level of 18.8 mmol/L, close monitoring and addressing the underlying cause should be the primary approach, as this level is just above the threshold where pharmacological intervention would typically be recommended. Treatment with sodium bicarbonate should be reserved for cases with clinical symptoms or specific risk factors for complications of chronic acidosis.