Which of the following is an example of a sentinel event?

• A. Falls
• B. Unintended retention of a foreign object
• C. Suicide
• D. Wrong surgery

Answer: (D)

Sentinel events are unexpected occurrences in healthcare that result in death or serious physical or psychological injury, or the risk thereof, and they require immediate investigation to identify system failures and prevent recurrence. Wrong-site surgery is the best example because it is a preventable, catastrophic error that directly involves the core surgical care process and signals a breakdown in verification steps, site marking, and the preoperative timeout. This kind of event clearly meets the definition: it is unintended, highly preventable, and carries the potential for the most severe patient harm, prompting urgent investigation and corrective action to improve safety. While other events like a fall, unintended retention of a foreign object after surgery, or a patient suicide in a healthcare setting can be sentinel events if they lead to significant harm, wrong-site surgery is the classic, definitive illustration used to teach the concept.