Here are a few ways to continue the sentence:

1. The doctor phoned the nurse because he was late for the morning rounds.

2. The doctor phoned the nurse because he was late in submitting the patient's test results.

3. The doctor phoned the nurse because he was late for an important surgery and needed her to prepare the operating room.

4. The doctor phoned the nurse because he was late arriving at the hospital and wanted her to start seeing patients until he got there.

5. The doctor phoned the nurse because he was late meeting with the patient's family and needed her to provide an update on the patient's condition.
