Treatment of Metabolic Acidosis in Specific Patient Populations

Diagnostic Approach and Monitoring

• The American Journal of Kidney Diseases recommends monitoring serum bicarbonate levels monthly in maintenance dialysis patients 1

Treatment Based on Etiology

• The American Diabetes Association, as published in Diabetes Care, recommends focusing on insulin therapy, fluid resuscitation, and electrolyte replacement for patients with diabetic ketoacidosis 2, 3
• The American Diabetes Association, as published in Diabetes Care, suggests that restoration of circulatory volume and tissue perfusion is a primary goal in the treatment of diabetic ketoacidosis 2, 3
• The American Diabetes Association, as published in Diabetes Care, recommends continuous intravenous insulin as the standard of care for critically ill and mentally obtunded patients with diabetic ketoacidosis 2, 3
• The American Diabetes Association, as published in Diabetes Care, notes that bicarbonate administration has not been shown to improve resolution of acidosis or time to discharge in diabetic ketoacidosis 2, 3
• The National Kidney Foundation, as published in the American Journal of Kidney Diseases, recommends treating chronic kidney disease-associated acidosis when serum bicarbonate is consistently < 18 mmol/L to prevent bone and muscle metabolism abnormalities 1
• The National Kidney Foundation, as published in the American Journal of Kidney Diseases, suggests that oral sodium bicarbonate (2-4 g/day or 25-50 mEq/day) can effectively increase serum bicarbonate concentrations in patients with chronic kidney disease-associated acidosis 1
• The National Kidney Foundation, as published in the American Journal of Kidney Diseases, recommends maintaining serum bicarbonate at or above 22 mmol/L in maintenance dialysis patients 1
• The National Kidney Foundation, as published in the American Journal of Kidney Diseases, notes that correction of acidemia has been associated with increased serum albumin, decreased protein degradation rates, and increased plasma concentrations of branched chain amino acids in patients with chronic kidney disease-associated acidosis 1

Special Considerations

• The guideline society recommends monitoring electrolytes, particularly potassium levels, as acidosis can cause hyperkalemia due to transcellular shift of potassium 4
• The guideline society notes that administration of bicarbonate solutions may worsen intracellular acidosis, reduce ionized calcium, and produce hyperosmolality 4

Treatment of Metabolic Acidosis in Chronic Kidney Disease

Etiology-Based Treatment Approach

• Citrate alkali salts should be avoided in CKD patients exposed to aluminum salts as they may increase aluminum absorption, according to the American Journal of Kidney Diseases 5, 6
• In children with renal tubular acidosis, normalization of serum bicarbonate is important for normal growth parameters, as recommended by the American Journal of Kidney Diseases 5, 6
• In patients with chronic metabolic acidosis, correction of acidosis can improve bone histology and reduce excess protein catabolism, as stated by the American Journal of Kidney Diseases 5, 6

Treatment of Metabolic Acidosis

Etiology-Based Treatment Approach

• The American College of Critical Care Medicine recommends that treatment of metabolic acidosis must be directed at the underlying cause rather than routine bicarbonate administration, as sodium bicarbonate has not demonstrated mortality benefit in most acute organic acidoses and may worsen intracellular acidosis 7
• For severe malaria in children, the World Health Organization recommends that metabolic acidosis resolves with correction of hypovolemia and treatment of anemia by adequate blood transfusion; no evidence supports sodium bicarbonate use 8

Common Pitfalls to Avoid

• The European Society of Intensive Care Medicine advises against using furosemide unless hypervolemia, hyperkalemia, and/or renal acidosis are present 7
• The European Society of Intensive Care Medicine recommends avoiding the use of dopamine in an attempt to improve renal function 7
• The European Society of Intensive Care Medicine advises against using hypotonic fluids (e.g., glucose solutions) for fluid resuscitation 7

Critical Monitoring Requirements

• The Advanced Paediatric Life Support guidelines recommend monitoring electrolytes, particularly potassium levels, as acidosis causes hyperkalemia due to transcellular potassium shift, and treating hyperkalemia according to their guidelines 8

Treatment of Metabolic Acidosis in Specific Clinical Scenarios

Etiology-Based Treatment Approach

• The American Diabetes Association recommends continuous intravenous insulin as the standard of care for critically ill and mentally obtunded patients with Diabetic Ketoacidosis (DKA), with the primary goal of restoring circulatory volume and tissue perfusion, along with resolution of ketoacidosis and correction of electrolyte imbalances 9
• The American Diabetes Association suggests that successful transition from intravenous to subcutaneous insulin in DKA patients requires administration of basal insulin 2-4 hours before stopping the intravenous insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia 9
• The American Diabetes Association recommends against bicarbonate administration in DKA, as it has not been shown to improve resolution of acidosis or time to discharge 9

Buffer Management in Continuous Renal Replacement Therapy (CRRT) Patients

• The Kidney Disease: Improving Global Outcomes (KDIGO) guideline suggests that either lactate or bicarbonate can be used as buffer in most CRRT patients, with bicarbonate being preferred in patients with lactic acidosis and/or liver failure 10

Management of Severe Metabolic Acidosis with Acute Kidney Injury

Immediate Priorities

• Hemodialysis is the definitive treatment for patients with severe acidosis (pH <7.20) and acute kidney injury, as it simultaneously corrects acidemia, removes uremic toxins, and manages volume status, according to the American Society of Nephrology 11
• Dialysis should not be delayed while attempting medical management, as the acidosis is refractory to conservative measures with this degree of renal impairment, as recommended by the American Society of Nephrology 11

Disposition and Follow-up

• Patients with severe metabolic acidosis and acute kidney injury require ICU-level care with nephrology consultation for urgent dialysis, as suggested by the American Society of Nephrology 11
• Once stabilized on dialysis, serum bicarbonate should be maintained ≥22 mmol/L through dialysate bicarbonate concentration adjustment, according to the American Society of Nephrology 11
• The American Society of Nephrology recommends that long-term management depends on whether renal function recovers or if chronic dialysis is needed 11

Treatment of Metabolic Acidosis with Sodium Bicarbonate

Etiology-Based Treatment Approach

• The American Diabetes Association recommends bicarbonate administration only in patients with pH < 6.9 (Grade C recommendation) 12

Sodium Bicarbonate Therapy: When and How

• The American Diabetes Association suggests that for children, 1-2 mEq/kg IV of sodium bicarbonate can be given slowly 12

Management of Metabolic Acidosis in Severe Malaria

Treatment Approach

• In children with severe malaria, volume resuscitation with 20-40 ml/kg of 0.9% saline or 4.5% human albumin solution safely corrects hemodynamic features of shock, according to the BMJ 13
• The American Academy of Pediatrics recommends that in children presenting with coma and shock, human albumin solution should be considered the resuscitation fluid of choice, as stated in a study published in the BMJ 13