Management of Severe Metabolic Acidosis

Initial Assessment and Fluid Management

Severe metabolic acidosis (bicarbonate <15 mEq/L) requires prompt intervention with appropriate fluid therapy to correct both the acidosis and any associated volume depletion, according to the American Society of Nephrology 1, 2
Initial fluid therapy should focus on intravascular volume expansion and restoration of renal perfusion with isotonic saline (0.9% NaCl) at 15-20 ml/kg/hr during the first hour, as recommended by the American Diabetes Association 3
After initial volume resuscitation, fluid choice should be guided by the patient's hydration status, electrolyte levels, and urine output, according to the American Diabetes Association 4

For patients with severe metabolic acidosis (pH <7.1 and bicarbonate <10 mEq/L), intravenous sodium bicarbonate is indicated, as recommended by the American Society of Clinical Oncology 5

For patients with lactic acidosis or liver failure, bicarbonate-buffered solutions are preferred over lactate-buffered solutions, as the latter may worsen acidosis in these conditions, according to the American Society of Nephrology 1, 2
If the patient has concomitant hyperkalemia, sodium bicarbonate administration can help shift potassium into cells, providing temporary management of hyperkalemia, as recommended by the American Diabetes Association 4
For pediatric patients, if pH remains <7.0 after initial hydration, administration of 1-2 mEq/kg sodium bicarbonate over 1 hour is recommended, according to the American Diabetes Association 6

Overly rapid correction of acidosis can lead to paradoxical central nervous system acidosis, cerebral edema, and hypocalcemia, as warned by the American Diabetes Association 6
The maximum rate of reduction in serum osmolality should not exceed 3 mOsm/kg/hr to prevent cerebral edema, as recommended by the American Diabetes Association 4, 3
Monitor for signs of fluid overload, especially in patients with cardiac or renal dysfunction, as advised by the American Diabetes Association 3

For patients with severe metabolic acidosis and pH <7.1, and bicarbonate <10 mEq/L, the American Diabetes Association, as published in Diabetes Care, recommends intravenous sodium bicarbonate in addition to fluid therapy for severe acidosis 7
The British Medical Journal recommends bicarbonate therapy for severe acidosis, with an arterial pH <7.1 and base excess <-10, and in certain special situations, such as hyperkalemia or tricyclic antidepressant overdose, with a standard dose of 50 mmol (50 ml of an 8.4% solution) 8

The British Medical Journal suggests that bicarbonate therapy should be limited to severe acidosis and certain special situations, with further administration dependent on clinical situation and repeat arterial blood gas analysis 8