Final answer:
The most appropriate nursing intervention is to assist the patient with ambulation, carefully monitoring progress and managing pain effectively to ensure safe rehabilitation.
Step-by-step explanation:
For a patient admitted to a skilled care unit for rehabilitation after the surgical procedure of fixation of a fractured left hip, the most appropriate nursing intervention is to assist with ambulation and measure how far the patient walks. Considering the nursing diagnosis of Impaired physical mobility related to musculoskeletal impairment from surgery and pain with movement, it is crucial to ensure that movement is conducted safely and effectively to promote recovery while preventing complications such as pneumonia, pressure ulcers, and thrombophlebitis. Pain management is also important; giving pain medication prior to ambulation can help the patient move more easily and should be timed according to the patient's pain and scheduled activities.