Calculate the anion gap for Na 138, Cl 115, HCO3- 12. What is the value?

Calculate the anion gap for Na 138, Cl 115, HCO3- 12. What is the value?

• A. 11
• B. 15
• C. 25
• D. 1

Answer: (A)

Anion gap is calculated as sodium minus (chloride plus bicarbonate). This helps distinguish high-gap metabolic acidosis from normal-gap (hyperchloremic) metabolic acidosis. With the given values: 138 − (115 + 12) = 138 − 127 = 11. This result falls within the normal range (about 8–12 when potassium isn’t included). So the anion gap is normal. Note: a low bicarbonate with a high chloride, producing a normal anion gap, is typical of hyperchloremic metabolic acidosis rather than a high anion gap cause like lactate or ketoacidosis. If potassium were included in the calculation, the normal range would shift slightly, but the result here remains in the normal window.

Anion gap is calculated as sodium minus (chloride plus bicarbonate). This helps distinguish high-gap metabolic acidosis from normal-gap (hyperchloremic) metabolic acidosis.

With the given values: 138 − (115 + 12) = 138 − 127 = 11. This result falls within the normal range (about 8–12 when potassium isn’t included). So the anion gap is normal.

Note: a low bicarbonate with a high chloride, producing a normal anion gap, is typical of hyperchloremic metabolic acidosis rather than a high anion gap cause like lactate or ketoacidosis. If potassium were included in the calculation, the normal range would shift slightly, but the result here remains in the normal window.