Final answer:
An indwelling urinary catheter needs irrigation when there is the presence of sediment and clots in the urine, indicating a possible blockage.
Step-by-step explanation:
A nurse caring for a client with an indwelling urinary catheter should recognize the need for catheter irrigation when there is the presence of sediment and clots in the urine. This occurrence is indicative of circumstances that may block the catheter, such as the buildup of crystals or tissue, necessitating irrigation to ensure unimpeded urine flow. In contrast, clear, yellow urine; normal saline in the tubing; and mild discomfort during urination do not typically require catheter irrigation.