Dr. Anya Sharma, a PGY-1 internal medicine resident, is on her overnight shift in the busy intensive care unit of a large urban hospital in Ontario. While reviewing a critically ill patient's chart, she observes her supervising PGY-4 resident, Dr. Ben Carter, exhibiting slurred speech, poor judgment regarding medication dosages, and a faint smell of alcohol on his breath. Dr. Carter is preparing to perform a central venous line insertion on the patient, who is hemodynamically unstable. Dr. Sharma has previously seen Dr. Carter consume alcohol socially but never suspected on-duty impairment until now. Given the immediate risk to patient safety, which of the following is the most appropriate first action for Dr. Sharma to take?