## Do you correct sodium for anion gap in DKA?

## Do you correct sodium for anion gap in DKA?

Patients with diabetic ketoacidosis (DKA) frequently have hyperglycemia. Serum sodium in these patients should not be corrected for hyperglycemia to calculate the anion gap for acidosis because extracellular fluid shifts caused by hyperglycemia will dilute serum chloride and bicarbonate.

**How is corrected anion gap calculated?**

Some authors have proposed that the corrected anion gap (cAG)—anion gap corrected for albumin—be used in all critically ill patients. The cAG as proposed by Figge et al is calculated as follows: cAG (mmol/l) = anion gap + 0.25 × (normal albumin − measured albumin) (albumin is measured in g/l) [Equation 2].

### When should albumin anion gap be corrected?

The observed anion gap can be adjusted for abnormal albumin concentration as follows: adjusted anion gap = observed anion gap + 0.25 x ([normal albumin]-[observed albumin]), where albumin concentrations are in g/L; if given in g/dL, the factor is 2.5.

**Do you correct anion gap for hyperglycemia?**

No! The anion gap reflects the balance between positively and negatively charged electrolytes in the extracellular fluid. Glucose is electrically neutral and does not directly alter the anion gap.

#### Why do we correct sodium for glucose?

Because hyperglycemia can depress sodium concentration, patients with hyponatremia might be overlooked during severe hyperglycemia. We hypothesized that the corrected serum sodium level for severe hyperglycemia should be a prognostic factor to predict clinical outcomes in severe hyperglycemic patients.

**What is the anion gap for DKA?**

In mild DKA, anion gap is greater than 10 and in moderate or severe DKA the anion gap is greater than 12. These figures differentiate DKA from HHS where blood glucose is greater than 600 mg/dL but pH is greater than 7.3 and serum bicarbonate greater than 15 mEq/L.

## How is anion gap calculated for DKA?

The anion gap is calculated by subtracting the serum concentrations of chloride and bicarbonate from the sodium concentration. A difference of greater than 12 mEq/L along with a lowered bicarbonate level (<15 mEq/L) shows the presence of an anion gap metabolic acidosis and is a defining feature of DKA.

**How do you adjust albumin anion gap?**

Conclusions: The observed anion gap can be adjusted for the effect of abnormal serum albumin concentrations as follows: adjusted anion gap = observed anion gap + 0.25 x ([normal albumin] [observed albumin]), where albumin concentrations are in g/L; if given in g/dL, the factor is 2.5.

### How do you adjust the anion gap of albumin?

**Why is albumin used in anion gap?**

Raised serum albumin (hyperalbuminemia) can increase anion gap by the same mechanism that reduced serum albumin (hypoalbuminemia) reduces anion gap [9]. Small increases in anion gap (of the order 4-6 mmol/L) are evident in patients suffering metabolic alkalosis uncomplicated by other acid-base disturbance [25].

#### Why do you correct for sodium in hyperglycemia?

**What is anion gap in DKA?**