What is the treatment for severe metabolic acidosis with hyperkalemia (elevated potassium), hyperlactatemia (elevated lactate), and impaired renal function (acute renal failure)?

From the Guidelines

For severe metabolic acidosis with hyperkalemia, hyperlactatemia, and impaired renal function, immediate renal replacement therapy (RRT) is recommended to correct both the acidosis and hyperkalemia, as it is the most effective way to remove acid, correct electrolyte abnormalities, and address the underlying renal failure 1. The treatment approach should prioritize correcting the life-threatening hyperkalemia and acidosis.

• Administer sodium bicarbonate 1-2 mEq/kg IV over 1-2 hours, followed by an infusion of 150 mEq in 1L D5W at 50-100 mL/hour to help correct the metabolic acidosis, especially since the patient has a metabolic acidosis with a pH of 7.10 and bicarbonate 14 mEq/L 1.
• For the dangerous hyperkalemia, give calcium gluconate 10% (10 mL IV over 2-3 minutes) to stabilize cardiac membranes, insulin 10 units IV with 50 mL of 50% dextrose to shift potassium intracellularly, and consider nebulized albuterol 10-20 mg 1.
• The elevated lactate level (3.5 mmol/L) indicates tissue hypoperfusion, and the treatment should focus on improving perfusion and oxygen delivery to tissues.
• Continuous cardiac monitoring is essential throughout treatment to quickly identify any cardiac complications arising from the hyperkalemia or acidosis.
• The patient's respiratory status should be closely monitored, and mechanical ventilation should be considered if there are signs of respiratory fatigue or failure, as indicated by the elevated CO2 level 1.

From the FDA Drug Label

Sodium Bicarbonate Injection, USP is indicated in the treatment of metabolic acidosis which may occur in severe renal disease, uncontrolled diabetes, circulatory insufficiency due to shock or severe dehydration, extracorporeal circulation of blood, cardiac arrest and severe primary lactic acidosis Treatment of metabolic acidosis should, if possible, be superimposed on measures designed to control the basic cause of the acidosis Vigorous bicarbonate therapy is required in any form of metabolic acidosis where a rapid increase in plasma total CO2 content is crucial - e. g., cardiac arrest, circulatory insufficiency due to shock or severe dehydration, and in severe primary lactic acidosis or severe diabetic acidosis.

The treatment for severe metabolic acidosis with hyperkalemia, hyperlactatemia, and impaired renal function may include sodium bicarbonate (IV), as it is indicated for the treatment of metabolic acidosis in severe renal disease and severe primary lactic acidosis 2. However, treatment should be superimposed on measures designed to control the basic cause of the acidosis.

• Key considerations:
  • Vigorous bicarbonate therapy may be required in severe cases
  • Addressing the underlying cause of the acidosis is crucial
  • Monitoring and management of hyperkalemia and impaired renal function are also necessary, but the specific details of this are not provided in the label.

From the Research

Treatment for Severe Metabolic Acidosis

The treatment for severe metabolic acidosis with hyperkalemia, hyperlactatemia, and impaired renal function involves several approaches:

• Early correction of concurrent clinical problems, such as fluids and hemodynamic optimization in case of shock, mechanical ventilation in case of concomitant respiratory failure, and hemodialysis for acute intoxications 3
• Administration of alkalizing agents, such as sodium bicarbonate, should be carefully evaluated, taking into account the risk of side effects, as well as the potential need for renal replacement therapy 3, 4
• Hemodialysis using a bicarbonate concentrate is the treatment modality of choice for correction of metabolic acidosis in chronic renal failure, but improper ratios of acid and bicarbonate concentrates in dialysis fluid can result in iatrogenically induced metabolic acidosis 5
• Prolonged dialysis may be necessary for metformin-associated lactic acidosis (MALA) to improve outcomes, as metformin has a large volume of distribution and accumulates in erythrocytes and intestinal cells, resulting in less efficient removal with dialysis and rebound lactic acidosis 6
• Cessation of acid production via improvement of tissue oxygenation is the only effective treatment for organic acidosis, such as lactic acidosis, and treatment with sodium bicarbonate failed to reduce the morbidity and mortality despite improvement in acid-base parameters 7

Key Considerations

• Identifying the cause of acidosis is critical for its management 6, 7
• Patients receiving metformin should be counseled to stop metformin and seek medical care in the setting of illnesses, particularly given the frequency of metformin prescription and the common use of renin-angiotensin system blockade in patients with type 2 diabetes, which increases the risk of kidney dysfunction 6
• Awareness of the problem and a rapid examination of the dialysis fluid in patients who unexpectedly deteriorate rather than improve with hemodialysis may help in averting potentially severe complications due to errors in the concentrate selection 5