Final answer:
The most appropriate handwashing technique for the operating room nurse is to perform a surgical hand scrub using detergent.
Step-by-step explanation:
The most appropriate handwashing technique for the operating room nurse caring for a client undergoing an appendectomy is to perform a surgical hand scrub using detergent. Surgical scrubbing is more involved than routine handwashing. It requires scrubbing from the fingertips to the hands and forearms, and then up beyond the elbows.