What are the features of the paediatric central nervous system and psychology that differ from adults and what implications do these have?
Features
Implications
- Cerebral metabolic requirement for oxygen (CMRO2) and cerebral blood flow are higher in young children
- Brain forms higher % of body weight (10–15% of body weight at birth, but only 2% of body weight by the age of 8 years)
- More susceptible to periods of hypoglycaemia, hypoxia and decreased cerebral blood flow
- Blood brain barrier is poorly formed
- Drugs such as barbiturates, opioids, antibiotics and bilirubin cross the blood brain barrier easily causing a prolonged and variable duration of action
- Entry of ammonia into the brain can leads to hyperammonaemic encephalopathy
- Head is large and heavy relative to the size of the body
- Balanced on a neck poorly supported by weak muscles and ligaments
- Both head and cervical spine are easily injured
- Cerebral vessels in the preterm infant and neonate are thin walled and fragile
- Prone to developing intraventricular haemorrhages
- Anxiety related to separation, unfamiliar people and environments becomes marked over the age of 6 months
- Parental anxiety readily perceived and reacted by children
- Anxiety and associated behavioural change can lead to a significant impact on outcomes such as pain and length of stay
- Reducing child and parent anxiety important in optimising outcomes from anaesthesia and intensive care