Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the primary treatment for Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH)?

1. Fluid restriction

2. Dialysis

3. Oxygen therapy

4. Electrolyte replacement

The correct answer is: Fluid restriction

Fluid restriction is recognized as the primary treatment for Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH) because the condition results in excessive retention of water due to the inappropriate release of antidiuretic hormone (ADH). This leads to hyponatremia, where the sodium levels in the blood are diluted due to excess fluid. By implementing fluid restriction, the overall fluid volume in the body is decreased, which helps to correct the sodium imbalance. In addition to fluid restriction, management may also involve monitoring sodium levels and in some cases, medications or other interventions may be considered to help correct severe hyponatremia, but initially restricting fluid intake remains crucial. This first approach helps in decreasing total body water, thus raising serum sodium levels and improving the patient’s condition. Other choices, such as dialysis or oxygen therapy, are not appropriate for this condition as they target entirely different medical issues, and electrolyte replacement may not address the underlying fluid overload caused by SIADH.