Pardoxical aciduria is seen in:
**Core Concept**
Paradoxical aciduria refers to the phenomenon where the urine pH becomes more acidic despite the administration of a base or a medication that increases urinary pH. This occurs due to the reabsorption of ammonia in the renal tubules, which leads to an increase in hydrogen ion excretion and a decrease in urinary pH.
**Why the Correct Answer is Right**
The correct answer involves the renal regulation of acid-base balance. The kidneys reabsorb ammonia (NH3) produced from glutamine in the proximal convoluted tubule (PCT). As ammonia reabsorption increases, it leads to an increase in the excretion of hydrogen ions (H+) in the urine, resulting in paradoxical aciduria. This mechanism is crucial for maintaining acid-base homeostasis in the body.
**Why Each Wrong Option is Incorrect**
**Option A:** Lactic acidosis would result in a decrease in urinary pH due to the presence of lactate, which is a strong acid. This is not an example of paradoxical aciduria.
**Option B:** Diabetic ketoacidosis (DKA) would result in a decrease in urinary pH due to the presence of ketones, which are strong acids. This is not an example of paradoxical aciduria.
**Option C:** This option is missing.
**Clinical Pearl / High-Yield Fact**
Paradoxical aciduria is a classic example of how the kidneys can regulate acid-base balance by adjusting the reabsorption of ammonia and hydrogen ions.
**Correct Answer: C. Alkali loading (e.g. bicarbonate loading) in patients with severe renal failure.**