Anion gap is increased in all except?
**Core Concept**
The anion gap (AG) is a calculated value that represents the difference between the measured cations and anions in the blood. It is an important indicator of the presence of unmeasured anions, such as lactate, ketones, and sulfates, which can accumulate in various metabolic disorders.
**Why the Correct Answer is Right**
The anion gap is increased in conditions where there is an accumulation of unmeasured anions. This can occur in diabetic ketoacidosis (DKA), lactic acidosis, and renal failure. In DKA, the increased production of ketone bodies leads to an increase in the anion gap. In lactic acidosis, the accumulation of lactate ions increases the anion gap. Renal failure can lead to an increase in the anion gap due to the accumulation of sulfates and other unmeasured anions.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a condition that actually increases the anion gap. Diabetic ketoacidosis (DKA) is characterized by the increased production of ketone bodies, which leads to an increase in the anion gap.
**Option B:** This option is incorrect because it is a condition that actually increases the anion gap. Lactic acidosis is characterized by the accumulation of lactate ions, which increases the anion gap.
**Option C:** This option is incorrect because it is a condition that actually increases the anion gap. Renal failure can lead to an accumulation of sulfates and other unmeasured anions, which increases the anion gap.
**Clinical Pearl / High-Yield Fact**
A high anion gap can be a marker of a serious underlying condition that requires prompt medical attention. It is essential to investigate the cause of an increased anion gap and to treat the underlying condition promptly to prevent complications.
**Correct Answer:** D.