# Sentinel events

*No executive summary as currently short*

## Definition of a sentinel event

A sentinel event is a patient safety event that results in death, permanent harm, or severe temporary harm. Specific acute clinical events which occur close to the time of delivery or are the primary reason for delivery are called perinatal sentinel events (PSE).[[Shankaran et al. 2017]](https://doi.org/10.1016%2Fj.jpeds.2016.09.026) Sentinel events associated with HIE are those that interrupt oxygen flow or blod flow to the infant.[[Ellenberg and Nelson 2012]](https://doi.org/10.1111/dmcn.12016):

As explained by Steve Thronton, "they are usually clinical findings such as bleeding with abruption abruption, or the identification of a cord prolapse".

## Possible sentinel events for HIE

* Uterine rupture - uterus tears and baby slips into abdomen
* Umbilical cord mishap
    * Cord prolapse - umbilical cord slips down in front of baby through the open cervix after the waters have broken
    * Knotted cord - knots that form naturally from the fetus moving around
    * Ruptured cord - cord breaks or bursts
    * Compressed cord - cord flattened by pressure
* Tight nuchal cord - umbilical cord tightly wrapped around baby's neck
* Placental abruption - placenta comes away from uterus wall prematurely
* Shoulder dystocia - babies head is born but one of the shoulders becomes stuck behind the mother's pubic bone
* Severe maternal haemorrhage - blood loss
* Maternal cardiac arrest
* Trauma
* Seizures
* Amniotic fluid embolism - aminotic fluid enters maternal bloodstream

References for these being sentinel events:
* [[Nelson and Ellenberg 2013]](https://doi.org/10.1097/aog.0b013e3182a265ab) with reference to [[Internal Cerebral Palsy Task Force 1999]](https://doi.org/10.1136%2Fbmj.319.7216.1054) and [[Perlman 2006]](https://doi.org/10.1016/j.clp.2006.03.004))
* [[Shankaran et al. 2017]](https://doi.org/10.1016%2Fj.jpeds.2016.09.026)

## Incidence of sentinel events in HIE cases

Sentinel events account for 10-36% of cases of HIE - with the majority of HIE cases having no obvious cause.[[Leith et al. 2024]](https://doi.org/10.1016/j.annepidem.2023.11.011)