Intractable Acidosis Management

Definition and Diagnosis

The American Diabetes Association recommends that intractable acidosis be defined as severe, persistent metabolic acidosis (typically pH <7.1-7.2 or bicarbonate <10-15 mEq/L) that fails to respond to standard treatment of the underlying cause 1, 2
Severe acidemia with pH <7.0-7.1 despite aggressive treatment of the underlying disorder is a characteristic of intractable acidosis 2
The calculation of anion gap: [Na+] - ([Cl-] + [HCO3-]), with high anion gap >12 mEq/L, is crucial in determining the type of acidosis 2, 5

In Diabetic Ketoacidosis (DKA), intractable acidosis manifests as pH <7.0 with bicarbonate <10 mEq/L, representing severe DKA that may warrant bicarbonate therapy 2
The American College of Clinical Endocrinologists recommends that bicarbonate therapy be considered in DKA with pH <6.9-7.0, with the goal of achieving pH 7.2-7.3, not normalization 2, 3
Lactate levels exceeding 10 mmol/L are considered life-threatening and require immediate attention 3

The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend that continuous renal replacement therapy (CRRT) with bicarbonate-based dialysate be considered in patients with intractable acidosis and renal failure 1
Bicarbonate should only be administered in highly specific circumstances, such as DKA with pH <6.9-7.0 or severe acidosis with pH <7.1 from non-lactic causes 2, 3, 4
The American Society of Nephrology recommends that citrate anticoagulation be used with caution in patients at high risk for citrate accumulation, as it can cause both metabolic alkalosis and metabolic acidosis 1

The Surviving Sepsis Campaign recommends that serum lactate be measured regularly in critically ill patients, with levels >2 mmol/L considered elevated and >10 mmol/L considered life-threatening 3
The prognosis of intractable acidosis is determined by the underlying disease process, with hyperkalemia, APACHE II score, and Glasgow Coma Scale being determinants for ICU death 4