Wound, Ostomy and Continence Nurses Society (WOCN) Practice Exam

What is the primary purpose of nephrostomy tubes?

1. Decompress the renal pelvis when obstruction is present

2. Facilitate water retention in the kidneys

3. Help control urinary infections

4. Assist in wound drainage

The correct answer is: Decompress the renal pelvis when obstruction is present

The primary purpose of nephrostomy tubes is to decompress the renal pelvis when obstruction is present. This tube is inserted through the skin into the kidney and serves to drain urine directly from the kidney into an external collection bag. This is necessary when there is a blockage in the urinary tract that prevents normal urine flow, such as from a kidney stone, tumor, or severe urinary tract infection. By alleviating the pressure from the obstructed area, nephrostomy tubes help prevent kidney damage and reduce the risk of complications associated with urinary retention. Other options such as facilitating water retention in the kidneys, controlling urinary infections, or assisting in wound drainage do not align with the primary function of nephrostomy tubes. These tubes are specifically designed for urinary drainage rather than fluid retention or directly targeting infections. Their function is solely related to managing urinary flow when there is an obstruction, making decompression the key purpose of nephrostomy tubes.