A child with cystic fibrosis is receiving gentamicin. Which nursing action is most appropriate?

• A. Monitoring intake and output
• B. Obtaining daily weights
• C. Monitoring the client for constipation
• D. Obtaining stool samples for hemoccult testing

Answer: (A)

The main idea here is to protect kidney function while a child is receiving gentamicin, an aminoglycoside known to be nephrotoxic. Monitoring intake and output focuses on hydration status and kidney function; a decrease in urine output is an early sign of potential renal impairment from the drug. By tracking fluids in and out, the nurse can detect changes quickly and intervene to maintain adequate hydration and adjust care as needed, reducing the risk of drug-associated kidney injury. In a cystic fibrosis patient, where fluid balance can be delicate, this bedside measure becomes even more important.

Daily weights can help assess fluid balance but are less direct for detecting nephrotoxicity. Constipation and stool occult blood testing are not related to the renal toxicity risk posed by gentamicin.