Neonatal medicine (2)

Question 1

Hypoglycaemia

Answer 1

• Hypoglycaemia is particularly likely in the first 24 h of life in babies with intrauterine growth restriction, who are preterm, born to mothers with diabetes mellitus, are large-for-dates, hypothermic, polycythaemic or ill for any reason
• Recent evidence suggests that blood glucose levels above 2.6 mmol/L are desirable for optimal neurodevelopmental outcome, although during the first 24 h after birth many asymptomatic infants transiently have blood glucose levels below this level
• can usually be prevented by early and frequent milk feeding

Question 2

Neonatal seizures

Causes of neonatel seizures

Answer 2

Hypoxic-ischaemic encephalopathy
Cerebral infarction
Septicaemia/meningitis
Metabolic:

• Hypoglycaemia
• Hypo-/hypernatraemia
• Hypocalcaemia
• Hypomagnesaemia
• Inborn errors of metabolism
• Pyridoxine dependency

Intracranial haemorrhage
Cerebral malformations
Drug withdrawal, e.g. maternal opiates
Congenital infection

kernicterus

Question 3

Cerebral infarction

(neonatal stroke)

Answer 3

• Infarction in the territory of the middle cerebral artery may present with seizures at 12–48 h in a term infant.
• The seizures may be focal or generalised. In contrast to infants with hypoxic-ischaemic encephalopathy, there are no other abnormal clinical features
• prognosis is relatively good, with only 20% having hemiparesis or epilepsy presenting later in infancy or early childhood

Question 4

Craniofacial disorders

Cleft lip and palate

Answer 4

• may be unilateral or bilateral. It results from failure of fusion of the frontonasal and maxillary processes
• In bilateral cases the premaxilla is anteverted. Cleft palate results from failure of fusion of the palatine processes and the nasal septum
• syndrome of multiple abnormalities, e.g. chromosomal disorders.
• Some are associated with maternal anticonvulsant therapy. They may be detected on antenatal ultrasound scanning

Question 5

Craniofacial disorders

Pierre Robin sequence

Answer 5

• Pierre Robin sequence is an association of micrognathia, posterior displacement of the tongue (glossoptosis) and midline cleft of the soft palate
• The infant is at risk of failure to thrive during the first few months.
• If there is upper airways obstruction, the infant may need to lie prone, allowing the tongue and small mandible to fall forward.
• Persistent obstruction can be treated using a nasopharyngeal airway

Question 6

• *Gastrointestinal disorders
• Oesophageal atresia***

Answer 6

• Oesophageal atresia is usually associated with a tracheo-oesophageal fistula
• If the diagnosis is not made at this stage, the infant will cough and choke when fed, and have cyanotic episodes.
• There may be aspiration into the lungs of saliva (or milk) from the upper airways and acid secretions from the stomach
• Almost half of the babies have other congenital malformations, e.g. as part of the
• VACTERL association
  
  • (Vertebral,
  • Anorectal,
  • Cardiac,
  • Tracheo-oEsophageal,
  • Renal and Radial
  • Limb anomalies)

Question 7

Gastrointestinal disorders

Small bowel obstruction

Answer 7

Small bowel obstruction may be caused by:

• Atresia or stenosis of the duodenum – one-third have Down syndrome and it is also associated with other congenital malformations
• Atresia or stenosis of the jejunum or ileum – there may be multiple atretic segments of bowel
• Malrotation with volvulus – a dangerous condition as it may lead to infarction of the entire midgut
• Meconium ileus – thick inspissated meconium, of putty-like consistency, becomes impacted in the lower ileum; almost all affected neonates have cystic fibrosis
• Meconium plug – a plug of inspissated meconium causes lower intestinal obstruction.

Question 8

Gastrointestinal disorders

Large bowel obstruction

Answer 8

This may be caused by:

• Hirschsprung disease. Absence of the myenteric nerve plexus in the rectum which may extend along the colon.
• The baby often does not pass meconium within 48 h of birth and subsequently the abdomen distends. About 15% present as an acute enterocolitis.
• Rectal atresia. Absence of the anus at the normal site.
• Lesions are high or low, depending whether the bowel ends above or below the levator ani muscle.
• In high lesions, there is a fistula to the bladder or urethra in boys, or adjacent to the vagina or to the bladder in girls. Treatment is surgical.

Question 9

Gastrointestinal disorders

Exomphalos/gastroschisis

Answer 9

• In exomphalos abdominal contents protrude through umbilical ring, covered with transparent sac formed by the amniotic membrane and peritoneum. Associated with other major congenital abnormalities
• In gastroschisis, bowel protrudes through defect in the anterior abdominal wall, adjacent to the umbilicus, no covering sac. Not associated with other congenital abnormalities.