Neonatal Flashcards
What figure constitutes an unconjugated (indirect) jaundice?
CB less than 15% of total bilirubin
What figure constitutes a direct/conjugated jaundice?
Conjugated bilirubin greater than 15% of total or over 20mmol/L
What constitutes prolonged jaundice in term and preterm babies?
Term = 2 weeks of age plus Preterm = 3 weeks of age plus
6 areas of causes of conjugated hyperbilirubinaemia?
Sepsis Extrahepatic biliary obstruction TPN jaundice Toxic e.g. Aspirin, paracetamol, rifampicin, alcohol, steroids Neonatal hepatitis Metabolic or genetic
What type of jaundice is TPN associated jaundice?
Conjugated
6 areas of causes of unconjugated hyperbilirubinaemia?
Sepsis
Physiologic e.g. Breast milk
Haemolytic e.g. Rhesus/ABO
RBC defects e.g. G6PD def, hereditary spherocytosis/eliptocytosis or pyruvate kinase deficiency
Conjugation defects - Gilbert’s or Crigler Najjar
Other - galactosaemia, delayed cord clamping, cephalhaematoma/bruising, pyloric stenosis
What type of jaundice does congenital hypothyroidism cause?
Conjugated
What type of jaundice is breastfeeding/physiological jaundice?
Unconjugated
Why is jaundice more likely in neonates?
Increased bilirubin production due to higher haematocrit and higher red cell turnover due to decreased life span (85 days)
Decreased conjugation
Increased enterohepatic circulation due to reduced gut motility
What type is most neonatal jaundice and therefore what is more worrying?
Most is unconjugated
So conjugated potentially concerning
What is the typical pattern of physiological jaundice in neonates?
Occurs after 24 hours, peaks at 2-4 days and resolves within 1-2 weeks
Why does TPN cause jaundice? Which type?
Lower gut motility so increased enterohepatic circulation and increased absorption of conjugated bilirubin into blood
What does early (less than 24 hours after birth) jaundice often reflect?
Severe haemolysis e.g. ABO or rhesus
Other red cell or membrane defects
Or severe cephalhaematoma
What is more likely the cause of prolonged jaundice?
Infection or metabolic disease incl hypothyroidism
What type of hyperbilirubinaemia is worse for neurological function and can cause acute neonatal encephalopathy?
Unconjugated
What is kernicterus?
Chronic sequelae of often acute hyperbilirubinaemia (usually unconjugated), consisting of choreoathetoid CP (dyskinetic), SN hearing loss and loss of upgaze plus dental enamel dysplasia
Early to late signs of acute bilirubin encephalopathy?
Early hypotonia and high pitched cry
Febrile, poor feeding, lethargic
Later retrocolis, opisthotonos, apnoeas, seizures, hypertonic and death
What type of hyperbilirubinaemia is managed by UV phototherapy and why?
Unconjugated - converts unconjugated to water soluble photo-isomers which are then excreted in urine
What cause of unconjugated hyperbilirubinaemia is UV phototherapy often not very effective for?
Haemolysis
Side effects and considerations for UV phototherapy for neonatal jaundice?
Need to be well hydrated to maintain urine output
Can get eye damage, diarrhoea, skin rash, overheating
Also lack of parental contact
When might exchange transfusions or IVIg be used for hyperbilirubinaemia?
If very very high or quick rise
What is NRDS? After what gestation is it rare?
Lung disease in newborns due to surfactant deficiency - mostly a disease of the very premature, rare after 32 weeks
Give 4 metabolic disturbances that can inhibit surfactant production?
Acidosis
Hypothermia
Hyperglycaemia
Sepsis
How is NRDS prevented?
Maternal steroids
What is transient tachypnoea of the newborn TTN? What does it usually present following?
Due to delayed surfactant clearance or absorption of surfactant - commonly in the setting of elective CS
How do babies get congenital pneumonia and what bugs therefore usually cause it?
Inhalation of infected amniotic fluid e.g. Chorioamnionitis or maternal illness
Usually caused by GBS, E Coli, listeria, chlamydia etc.
What are the 3 main pathogenic features of meconium aspiration syndrome?
Mechanical airway blockage
Barrier preventing airway exchange
Chemical pneumonitis
What are exam findings for meconium aspiration syndrome?
Diffuse wet crackles, rhonchi
Respiratory acidosis
In setting of stained liquor
What infection can be related to meconium aspiration syndrome?
Listeriosis
What is bronchopulmonary dysplasia? Definition in terms of gestation?
Impaired alveolar development sometimes defined as oxygen requirement after 36 weeks gestation
What reduces the incidence of nec?
Breastfeeding
4 RFs for nec?
Prematurity
VLBW/IUGR causing gut ischaemia
Hypoxia
Polycythaemia or exchange transfusions
What part of the bowel does nec often affect?
Terminal ileum/caecum
What structural findings of the bowel characterise nec?
Subserosal gas on mesenteric border of bowel
Gangrenous necrosis on antemesenteric border
When does nec generally present? What makes it present later?
Usually presents in 2nd week of life - 8 to 10 days
Can be later in very premature babies
Early signs of nec?
Change in feeding tolerance - increased aspirates and gastric retention (residual milk in stomach pre feed)
Abdominal distension and vomiting
Later progressive signs of nec?
General illness and fevers Abdo tenderness Blood stained stool Ileus, perforation Shock, DIC, organ failure
What does XR show for nec?
Pneumatosis intestinalis and hepatic portal venous gas
What criteria is used to stage nec? Briefly outline them?
Bell’s staging criteria
Stage 1 is suspected nec - non specific illness, early GI signs in predisposed infant, XR shows dilated bowel
Stage 2 is definite nec - as above plus mild to moderate acidosis, thrombocytopenia, gross GI bleeding plus gas and thickened wall on XR
Stage 3 is advanced nec - shock, severe acidosis, DIC, significant bleeding, pneumoperitoneum etc.
What fbc disturbance is common and possibly severe in nec?
Thrombocytopenia
Management of nec?
Supportive initially - pass free drainage NG tube
Broad spec Abx for 2 weeks
Surgery as indicated - beware risk of short bowel syndrome
Where does caput succedaneum form and what is it?
Oedematous region forming between skin and galeal aponeurosis/periosteum
How can you tell a caput succedaneum?
It crosses suture lines