Sentinel event

A sentinel event is a term primarily used in healthcare and sometimes in other fields, such as aviation and the criminal justice system, with a potential high risk of situations that can result in death or serious injury. The term refers to an event that causes  death, permanent harm, severe harm, life-sustaining intervention, or significant threat of loss of life or function of a patient, passenger, or other person when the event could have been prevented or the risk minimized in some way. The sentinel event signals some change or improvement that can be made to the system to prevent similar events in the future. Examples of sentinel events include a patient who suffers complications because an instrument was left inside the body during surgery, an airplane passenger who dies because an error was made in a repair of the plane, and a murder that occurs after law enforcement officials mistakenly release the suspect from custody. While the term is used in relation to these events in aviation, law enforcement, and some other fields, it is most commonly associated with healthcare situations. 

Background

A sentinel is someone who stands watch and guards something of importance. The sentinel alerts others to danger or potential danger so action can be taken to prevent or minimize the threat. A sentinel event is an occurrence that indicates that there is a potential danger that needs to be addressed.

The concept of systematically addressing sentinel events began in America in the aviation industry when the Commercial Aviation Safety Team (CAST) was formed in 1997 following a 1996 plane crash. The team combined private parties in the aviation industry and the US government in a partnership to address safety issues. The term has been used in the medical field since the 1990s and has been defined by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), now known as the Joint Commission, an American nonprofit organization that conducts reviews and grants accreditation to tens of thousands of healthcare entities around the world.

Overview

In medicine, a sentinel event is a negative outcome for a patient that is not directly related to their medical condition. Errors in prescribing or administering medication, performing surgery on the wrong limb, or leaving an instrument or other surgical device inside the body are all examples of sentinel events. The situation is considered a sentinel event when it results in death or permanent injury to the patient or when death or permanent injury would have resulted if medical intervention was not made to prevent it. The injury can be physical or psychological. Guidance from the Joint Commission also states that a sentinel event may include situations in which severe harm occurs or where a patient requires life-sustaining treatment, even if the harm is not permanent. Sentinel events indicate something is not working in the system and changes are needed.

While many sentinel events are the result of mistakes by medical professionals, the term is not synonymous with medical errors. Sometimes, negative consequences arise from situations that are unanticipated, outside the scope of a medical professional’s care, or the result of the actions of someone other than a healthcare professional. For instance, sentinel events can also include situations in which a patient is assaulted, raped, or murdered, or dies by suicide while in a medical facility, or suffers trauma or death because of a fire or other disaster at the facility itself.

Accrediting organizations and individual healthcare facilities keep records on the number of sentinel events that occur. However, it is difficult to determine the true number of negative consequences that occur from sentinel events. This is because the records depend largely on self-reporting by the facilities. Fear of legal consequences and lawsuits can prevent some events from being reported. In addition, the real cause of some events may be obscured by the patient’s original medical condition. For instance, a patient who goes into a medical facility with severe traumatic injuries may be affected by a medication error or a mistake during surgery, but the death might be attributed to the injuries. In 2026, the Joint Commission and the National Quality Forum (NQF) announced that the Sentinel Event list would be aligned with the updated Serious Reportable Events (SRE) list. This change was intended to standardize how serious patient safety incidents are defined and reported across healthcare systems and to improve consistency in safety monitoring.

In some cases, a sentinel event is the result of a single person making a mistake. For example, a pharmacist may inadvertently send the wrong type of intravenous fluids to a patient. However, in many cases, sentinel events are more complicated than a single error by one person. For instance, the way the intravenous fluids are stored may contribute to the mistake made by the pharmacist, and the administering nurse might have an opportunity to catch the mistake by comparing the orders to the fluids received.

Facilities use careful investigations into sentinel events to help identify their causes and contributing factors. In many cases, the person or persons responsible for any mistakes will be identified as a result of the investigation. However, a sentinel event investigation is less focused on placing blame and more focused on finding and implementing procedures to prevent future events of a similar nature. This is true whether the event occurs in healthcare or another field.

Some ways that experts suggest for preventing recurrences of sentinel events include improving communication, using electronic systems to replace manual processes and record keeping, and having a point person to oversee all aspects of patient care or processes. For example, physicians called hospitalists work in only one hospital and can be more focused on the processes and patients in that one site than a physician who must attempt to balance patient concerns and the processes in multiple sites. This can reduce the likelihood of mistakes. Empowering and encouraging patients to take more active roles in their care can also help because the patient will be more likely to notice or question things that can lead to mistakes.

The approach to limiting and responding to sentinel events is similar in other fields. In aviation, the role of maintenance supervisors and air traffic controllers can replicate the oversight roles played by hospitalists, for instance. Electronic record-keeping can help the criminal justice system avoid accidentally releasing the wrong individuals. For those sentinel events that are triggered by the actions or inactions of an individual, training and vigilance in adhering to policies and procedures are the best ways to prevent dangerous events from occurring. Ultimately, it will be impossible to prevent all events with negative consequences, but thorough investigation and honest assessments of the causes of sentinel events that do occur can help minimize repeat occurrences.

Bibliography

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