American Association of Critical-Care Nurses (AACN) Certification Practice Test

What is described as a form of renal replacement therapy that does not remove toxins from the blood?

1. Hemodialysis

2. Dry ultrafiltration

3. Peritoneal dialysis

4. Continuous renal replacement therapy

The correct answer is: Dry ultrafiltration

The concept of renal replacement therapy primarily revolves around strategies that assist or replace the function of kidneys in filtering blood and removing waste products. Dry ultrafiltration is a process that plays a specific role in fluid management rather than toxin removal. Unlike methods such as hemodialysis or peritoneal dialysis, which actively filter toxins and excess substances from the blood, dry ultrafiltration specifically focuses on the removal of excess fluid without eliminating solutes or toxins from the bloodstream. This approach is often utilized in managing fluid overload situations, particularly in patients who may not tolerate traditional dialysis methods. Conversely, modalities like hemodialysis and peritoneal dialysis are designed to clear both toxins and excess water from the body. Continuous renal replacement therapy also operates on the principle of removing toxins and is practical for patients with acute kidney injury in critical care settings, providing continuous filtration of blood. By identifying dry ultrafiltration as the correct answer, it highlights an understanding of how various renal replacement therapies function, specifically regarding their efficacy in managing different parameters such as toxins versus fluid overload.