Hypoxic ischaemic encephalopathy Flashcards
(15 cards)
What is HIE?
A result of prolonged hypoxia during birth (lack of oxygen)
What is ischaemia?
Restriction of blood flow to the brain
What is encephalopathy?
Malfunctioning of the brain
What can HIE lead to?
Permanent damage to the brain → cerebral palsy
Severe HIE can lead to death.
When should HIE be suspected?
When there are events that could lead to hypoxia during the perinatal or intrapartum period
- Acidosis (pH <7) on the umbilical ABG
- Poor APGAR scores
- Features of mild, moderate or severe HIE
- Evidence of multi organ failure
What are the causes of HIE?
Anything that leads to asphyxia (deprivation of oxygen) to the brain, e.g., maternal shock, intrapartum haemorrhage, prolapsed cord, nuchal cord
What are the risks for HIE?
- pre-eclampsia
- issues with umbilical cord, prolapse, uterus
- maternal infection (CMV, rubella) or infection in fetus
- heart of lung problems
- anaemia in the fetus
- internal bleeding by the birth mother and fetus
- problem during labour and delivery that restrict blood flow to the infant
- very premature births - if born with HIE, don’t treat them as not sure what will happen
- physical trauma to the brain or skull
- poor positioning during delivery eg. shoulders stuck during delivery
What is used to stage HIE?
Sarnat staging
What is considered as mild HIE?
- Poor feeding
- generally irritable and hyper alert
- Resolves within 24 hours
- Normal prognosis
What is moderate HIE?
- **Poor feeding
- lethargic, hypotonic and seizures**
- Can take weeks to resolve
- Up to 40% develop cerebral palsy
What is severe HIE?
Reduced consciousness, apnoeas, flaccid and reduced or absent reflexes
- Up to 50% mortality
- Up to 90% develop CP
How is HIE managed?
NICU, supportive care with neonatal resuscitation, ongoing optimal ventilation, circulatory support, nutrition, acid base balance, treatment of seizures, nutritional balance, therapeutic hypothermia, acid base balance, managing seizures
What is therapeutic hypothermia?
Actively cooling the core temperature of the baby according to strict protocol
- The baby is transferred to neonatal ICU and actively cooled using cooling blankets and a cooling hat
- The temperature is monitored with a target of between 33-34 degrees
How long is therapeutic hypothermia continued for?
72 hours, after which the baby is gradually warmed to a normal temp over 6-12 hours
What is the intention of therapeutic hypothermia?
Helps to protect the brain from hypoxic injury, reduce inflammation and neurone loss after the acute hypoxic injury, and reduces the risk of cerebral palsy, developmental delay, learning disability, blindness and death
