Prescribing Safety Assessment (PSA) Practice Exam

What are the three causes of hypervolemic hyponatraemia?

1. Heart Failure, Renal Failure, Liver Failure

2. Dehydration, Addison's disease, Liver Failure

3. Diuretics, Renal Failure, Heart Failure

4. Fluid loss, Shock, Renal Failure

The correct answer is: Heart Failure, Renal Failure, Liver Failure

Hypervolemic hyponatraemia occurs when there is an excess of fluid in the body, leading to a dilution of sodium in the bloodstream. The correct answer identifies heart failure, renal failure, and liver failure as the primary causes of this condition. In heart failure, the heart's inability to pump effectively leads to fluid retention and subsequent dilutional hyponatraemia. The body tries to compensate for the decreased cardiac output by promoting water retention through neurohormonal mechanisms, leading to increased total body water. Renal failure results in the kidneys' compromised ability to excrete water and electrolytes, which can contribute to fluid overload. The retention of excess water can further dilute serum sodium levels, producing hypervolemic hyponatraemia. Liver failure, particularly in conditions like cirrhosis, can cause portal hypertension and activate the renin-angiotensin-aldosterone system, leading to fluid retention. The resultant increase in total body water causes dilution of serum sodium, again leading to hypervolemic hyponatraemia. In contrast, other options suggest causes that don't predominantly lead to hypervolemic hyponatraemia. For instance, dehydration is associated with hypovolaemia, while conditions like Addison's disease