Final answer:
The nurse should continue to drain the bladder until empty.
Step-by-step explanation:
Based on the information provided, the nurse should continue to drain the bladder until empty. The immediate collection of 750 mL of clear yellow urine indicates that the client has been retaining a significant amount of urine. Continuing to drain the bladder until empty will ensure that all the retained urine is removed and relieve the client's urinary retention.