Mrs. Bigda, a 60-year-old woman, was brought to the hospital by the police after falling to the pavement. She is found to have alcoholic hepatitis. She is put on a salt- and protein-restricted diet and diuretics are prescribed to manage her ascites (accumulated fluid in the peritoneal cavity). How will diuretics reduce this excess fluid? Name and describe the mechanisms of action of three types of diuretics. Why is her diet salt-restricted?

Verified step by step guidance

1. Diuretics help reduce excess fluid by increasing urine production, which decreases fluid volume in the body, including the peritoneal cavity.
2. The first type of diuretic is a loop diuretic, which acts on the ascending loop of Henle in the nephron to inhibit sodium and chloride reabsorption, leading to increased urine output.
3. The second type is a thiazide diuretic, which works on the distal convoluted tubule to block sodium reabsorption, also increasing urine production.
4. The third type is a potassium-sparing diuretic, which acts on the collecting ducts and distal tubules to inhibit sodium reabsorption while conserving potassium, thus promoting diuresis without causing hypokalemia.
5. A salt-restricted diet is important because excess sodium can lead to water retention, exacerbating ascites and counteracting the effects of diuretics.

Key Concepts

Diuretics and Fluid Management

Diuretics are medications that promote the excretion of water and electrolytes through urine. They are commonly used to manage conditions like ascites by reducing fluid overload in the body. By increasing urine output, diuretics help to alleviate symptoms associated with fluid retention, such as swelling and discomfort.

Mechanisms of Action of Diuretics

Diuretics can be classified into three main types: loop diuretics (e.g., furosemide), thiazide diuretics (e.g., hydrochlorothiazide), and potassium-sparing diuretics (e.g., spironolactone). Loop diuretics inhibit sodium and chloride reabsorption in the loop of Henle, thiazides act on the distal convoluted tubule to prevent sodium reabsorption, and potassium-sparing diuretics block aldosterone receptors, reducing sodium reabsorption while conserving potassium.

Salt Restriction in Diet

A salt-restricted diet is crucial for patients with ascites, particularly in cases of liver disease like alcoholic hepatitis. Excess sodium intake can lead to fluid retention, worsening ascites and increasing the risk of complications. By limiting salt, the diet helps to manage fluid balance and reduce the workload on the liver, promoting better overall health outcomes.