Final answer:
Sentinel events are clearly identifiable, preventable, and serious errors in medical care that serve as a warning or signal for improvements in the healthcare system.
Step-by-step explanation:
Sentinel events are errors in medical care that are clearly identifiable, preventable, and serious in their consequences for patients. They are called sentinel events because they serve as a signal or warning that something is wrong in the healthcare system and needs to be addressed. These events are reported to the Joint Commission, an organization that accredits healthcare organizations in the United States, to facilitate learning from each event and to improve patient safety. For example, a wrong-site surgery or a medication error resulting in patient harm would be considered a sentinel event.