1. Blood biochemistry reveals normal anion gap metabolic acidosis
2. There is defective secretion of H$^+$ in the distal tubule.
3. There may be associated muscle weakness and rickets.
4. Children may present with polydipsia and polyuria.
Which of the above statements are correct?
Distal Renal Tubular Acidosis: Statement Analysis
This question requires evaluating statements about Distal Renal Tubular Acidosis (dRTA).
Evaluating dRTA Statements
- Statement 1: Blood biochemistry reveals normal anion gap metabolic acidosis. This is correct. In dRTA, the impaired excretion of hydrogen ions ($H^+$) leads to a buildup of acid, causing metabolic acidosis. However, the anion gap typically remains normal because the excess acid is buffered by bicarbonate, and no significant increase in unmeasured anions occurs.
- Statement 2: There is defective secretion of H$^+$ in the distal tubule. This is the hallmark of dRTA (Type 1 RTA). The cells in the distal nephron are unable to adequately secrete $H^+$ ions into the tubular lumen, impairing acid excretion.
- Statement 3: There may be associated muscle weakness and rickets. This statement is correct. The chronic acidosis and potential electrolyte disturbances (like hypokalemia and hypocalcemia) associated with dRTA can lead to symptoms such as muscle weakness. Hypocalcemia can cause bone issues, including rickets in children.
- Statement 4: Children may present with polydipsia and polyuria. This is also correct. Impaired urinary acidification can affect the kidney's ability to concentrate urine, leading to excessive water loss (polyuria) and increased thirst (polydipsia), similar to nephrogenic diabetes insipidus.
Conclusion on Correct Statements
All four statements (1, 2, 3, and 4) accurately describe key features of distal renal tubular acidosis.
Final Answer Determination
Since statements 1, 2, 3, and 4 are all correct, the option including all of them is the right choice.
Important Questions from Acid-Base Disorders
- The most common acid-base disturbance in critically ill patients is :
- Salicylate intoxication in adults usually causes:
1. Severe respiratory alkalosis.
2. Mixed metabolic acidosis respiratory alkalosis.
3. Hyperchloremic metabolic acidosis.
Select the correct answer using the code given below - Which one of the following pairs is not correctly matched?
Consider the following:
1. Normal anion gap
2. Hyperchloraemic acidosis
3. Inappropriately high urinary pH (>5.4)
Which of the above are the characteristic features of renal tubular acidosis (RTA)?- Which one of the following is not an example of metabolic acidosis with high anion gap?
