Hypoxic Ischaemic Encephalopathy Flashcards
What causes hypoxic ischaemic encephalopathy?
Hypoxia during birth
What is hypoxia?
A lack of oxygen
What is ischaemia?
A restriction in blood flow to the brain
What is encephalopathy?
Malfunctioning of the brain
What can HIE lead to?
Permanent damage to the brain, causing cerebral palsy.
What can severe HIE lead to?
Death
What can cause HIE?
Anything that leads to asphyxia to the brain can cause HIE.
What is asphyxia?
Deprivation of oxygen
What are possible causes of HIE?
- Maternal shock
- Intrapartum haemorrhage
- Prolapsed cord, causing compression of the cord during birth
- Nuchal cord
What is nuchal cord?
The cord is wrapped around the neck of the baby
What is the name of the grading scale used for HIE?
Sarnat Staging
What are the features of Mild HIE?
- Poor feeding, generally irritability and hyper-alert
- Resolves within 24 hours
- Normal prognosis
What are the features of moderate HIE?
- Poor feeding, lethargic, hypotonic and seizures
- Can take weeks to resolve
- Up to 40% develop cerebral palsy
What do 40% of neonates with moderate HIE develop?
Cerebral palsy
What are the features of severe HIE?
- Reduced consciousness, apnoeas, flaccid and reduced or absent reflexes
- Up to 50% mortality
- Up to 90% develop cerebral palsy
What percentage of neonates with severe HIE develop cerebral palsy?
90%
What percentage of neonates with severe HIE die?
50%
What is the management of HIE?
Supportive care
What does supportive care for HIE include?
Neonatal resuscitation Ongoing optimal ventilation Circulatory support Nutrition Acid base balance Treatment of seizures.
What is an option for neonates with HIE to prevent against hypoxic brain damage?
Therapeutic hypothermia
What does therapeutic hypothermia involve?
Actively cooling the core temperature of the baby according to a strict protocol.
How is the temperature of the baby monitored with therapeutic hypothermia?
Carefully monitored with a target of between 33 and 34°C, measured using a rectal probe.
How long is therapeutic hypothermia carried out?
72 hours
What is the mechanism of action of therapeutic hypothermia?
Reduces inflammation and neurone loss after the acute hypoxic injury.
What diseases can therapeutic hypothermia reduce the risk of?
Cerebral palsy
Developmental delay
Learning disability
Blindness and death.
