Neonatal and newborn conditions Flashcards
Is neonatal jaundice common? Esp in who?
Yes mild is common esp in pre-term
Which time scales of neonatal jaundice need investigation?
First 24hr or lasting beyond 2w
What builds up in neonatal jaundice? What are the two types?
Bilirubin Unconjugated Conjugated
What two mechanisms cause unconjugated hyperbilirubinaemia?
Excessive haemolysis or impaired conjugation
What are the 8 causes of unconjugated hyperbilirubinaemia?
Prematurity (immature liver enzymes)
- Rh incompatible (haemolytic disease of the newborn (see notes at bottom). Coomb’s test positive.)
- ABO incompatible (usually milder than Rh)
- Infection (bacterial)
- Bruising (traumatic delivery)
- Hypothyroid (?pituitary disease)
- Breast milk jaundice
- Physiological
What is physiological unconj hyperbil. due to? what might it need treatment with?
- low liver enzyme activity (liver immaturity, particularly in pre-term) or breakdown of foetal haemoglobin. Occasionally needs phototherapy.
What is breast milk jaundice?
otherwise well baby who is breast-fed develops jaundice day 4-7 until week/month 3. Normal coloured stool and urine. Inhibition of liver conjugation enzymes by breast milk. Diagnosis of exclusion- measure split bilirubin to exclude conjugated hyperbilirubinaemia.
What test would be positive in haemolytic disease of the newborn?
Coomb’s test (rhesus)
Why does conjugated hyperbil. occur?
Obstruction of drainage of bile ducts
What are the 4 reasons conj, hyperbil. occurs?
Hepatitis CF Choledocal cyst Biliary atresia
What are the different types of hepatitis that could cause conj. hyperbil/?
A, B, C, CMV Inborn error of metabolism e.g. galactosaemia
Is biliary atresia common?
No 1 in 10,000
What is biliary atresia? What are the signs? What would an investigation show? What is the management and what happens if untreated?
o Persistent jaundice with rising conjugated fraction over weeks. (>20% after 2 weeks = refer, any jaundice persisting after 2 weeks should have both bilirubins checked.) o Pale, chalky stools o Due to absence of intra/extrahepatic bile ducts. o Undiagnosed- liver failure and may die without transplant. o Urgent referral to paediatric hepatologists for assessment, diagnostic isotope scan and surgical correction.
What is the normal breakdown of bilirubin?
RBC breakdown (haem)→ biliverdin→ unconjugated (lipid soluble, can cross BBB) bilirubin → conjugation occurs in liver, conjugated bilirubin is water soluble → enters gut via bile → gut enzymes break it down into urobilinogen → 80% excreted in faeces as stercobilinogen, 2% in urine as urobilin and 18% enter enterohepatic circulation.
Important things to ask in the history of neonatal jaundice?
• Age developed (within 24h investigate) • Risk factors for infection • Fhx e.g. CF, spherocytosis • How is baby? Active, alert, feeding well? Lethargic and must be woken for feeds (sig. jaundice) • Breast feeding?
Examination findings of neonatal jaundice?
• Extent (spreads head down) • Features of congenital viral infection e.g. petechiae, anaemia, hepatosplenomegaly • Dehydrated? • Pale stool • Baby well in general?
Investigations for neonatal jaundice? What is the justification for each?
• Bloods: o FBC (thrombocytopenia = viral infection or IUGR, anaemia = haemolytic disease, neutropenia or neutrophilia in infxn) o CRP (?) o Group and Coombs (ABO and Rh) o TFT o LFT (high ALT suggests hepatitis) o Coag o TORCH screen (for Hep B, CMV) • Urine metabolic screen (inborn errors of metabolism) • Liver USS • Liver isotope scan (r/o biliary atresia in persistent conjugated hyperbilirubinaemia) • ?Urine and CSF infection screen
Management options for neonatal jaundice (5)
Identify cause and severity Phototherapy Exchange transfusions Refer to hepatology if biliary atresia Vitamin K supplement depending on coag screen results
What does phototherapy do in neonatal jaundice?
Blue light 450nm wavelength converts unconjugated bilirubin to biliverdin (an isomer that can be excreted by the kidneys. In rhesus or ABO incompatibility, if bilirubin levels rise significantly despite phototherapy, may need exchange transfusion.)
When are exchange transfusions needed in neonatal jaundice and why?
Severe neonatal jaundice to prevent kernicterus
What is kernicterus?
When free bilirubin crosses BBB, deposited in basal ganglia- acute encephalopathy with irritability, high pitched cry or coma. Can lead to deafness and athetiod cerebral palsy.
What is haemolytic disease of the newborn?
If ABO or Rh incompatible, Maternal IgG crosses placenta, reacts with foetal RBC antigens.
What happens with haemolytic disease of the newborn in utero?
Foetal anaemia can = hydrops (severe oedema)
What is the in-utero management of haemolytic disease of the newborn?
Could have intra-uterine blood transfusion if severe Should be delivered before severe haemolysis
In babies with haemolytic disease of the newborn, what happens after birth?
Anaemic and quickly become severely jaundiced
Treatment for haemolytic disease of the newborn after birth?
o ‘Wash out’ maternal antibodies and bilirubin with exchange transfusions and phototherapy. o Can give IV Ig to block antibody sites.
How long might haemolytic disease of the newborn persist?
Several weeks (might still have some Ig around for a bit)
Not obvious reasons a paediatrician should be present at a birth
Meconium stained liquor vacuum, mid/high forceps delivery prolonged ROM
The infants condition after birth is described using the ____ score
APGAR
what do the bits of apgar stand for?
appearance pulse grimace (reflex irritability- suction pharynx to test) activity (muscle tone) RR
What is max apgar score?
10
What is a normal APGAR at one minute
7-10
At one minute an apgar score of what indicates a moderately depressed baby
4-6
At one minute apgar of 0-3 indicates what?
Severely depressed baby
Babies who require active resuscitation can be divided into what two groups?
Primary apnoea and secondary apnoea
What is primary apnoea
Blue colour due to failure to establish spontaneous respiration, but cardio system intact with good circulation Apgar at 1min 4-6
What is secondary apnoea?
White colour at birth as failure of circulation as well as respiration. Will die without vigorous resus. Slow or absent HR. Apgar at 1min 0-3
What normally happens to amniotic fluid during delivery?
Expelled from lungs by contractions
How can you encourage breathing at birth?
Dry with warm towel Gently suck out oropharynx Give to mother to put on breast or cuddle
Apnoiec within the first _____ requires basic resus
Minute
Will blue or white babies start to gasp even if nothing is done?
Blue
Do blue babies require lung inflation, cardiac support or both?
Lung inflation
Do white babies require lung inflation, cardiac support or both?
Both
How does tissue hypoxia lead to tissue acidosis?
Lactic acid and CO2
What is the accepted clinical definition of asphyxia?
N/A doesn’t exist
What are some used definitions of asphyxia?
Cord blood gas <7.05 0-5 APGAR at 10mins >10m to establish spont respiration Hypoxic-ischaemic encephalopathy
What is hypoxic ischaemic encephalopathy?
Abnormal neuro signs including convulsions lasting >2 days
How do you manage birth asphyxia?
Rapid and effective resus at birth Avoid cerebral oedema and treat convulsions
Prognosis of asphyxiated infants?
25% severely asphyxiated full term infants die or are severely handicapped Therapeutic cooling can improve neuro outcomes in survivors
What are the 3 categories of HIE?
Mild, mod, severe
What is mild HIE like?
Increased muscle tone, brisk tendon reflexes, transient behavioural abnorms like poor feeding or excessive crying. Typically resolves in 24h
What is moderate HIE like?
Lethargic, hypotonia, diminished reflexes. Grasping/moro/sucking reflexes may be absent. Periods of apnoea. Seizures in first 24h after birth. Full recovery within 1-2w possible
What is severe HIE like?
Seizures delayed and severe, may be initially resistant to conventional treatment. Usually generalised, freq may increase in the first 24-48h after onset (reperfusion injury).
What is a cephalohaematoma
Haemorrhage of blood between skull and periosteum
Why does cephalohaematoma occur in neonate
rupture of blood vessels crossing the periosteum usually due to prolonged second stage of labour or forceps delivery (not ventous)
Does cephalohaematoma pose a risk to brain cells?
No, considered a minor injury
How does cephalohaematoma present?
soft, fluctuant swelling on head appearing soon after birth
Do cephalohaematomas extend beyond the edges of the bone or cross suture lines?
No
Severe cephalohaematoma can cause what 3 things?
Jaundice, anaemia, hypotension
What can complications of cephalohaematoma be?
It may indicate linear skull fracture, or be at risk of infection (osteomyelitis, meningitis)
How long does it take for cephalohaematoma to resolve
Weeks. It calcifies in that time and appears as a depressed fracture
cephalohaematoma should be distinguished from ___?
sugaleal haemorrhage- between scalp and skull bone (above periosteum)- this is more extensive and prone to complications (anaemia and bruising)
Management cephalohaematoma
Mainly observational IF NEURO Sx- Skull xray or CT IF JAUNDICE- phototherapy IF ANAEMIA- blood transfusion (rare) consider bleeding disorder (unlikely)
Do you need to take bloods for cephalohaematoma?
Not usually
Should you aspirate a cephalohaematoma?
No risk of infection and abscess formation
Prematurity is defined as what gestation?
<37w
‘extremely premature’ is ? gestation
<28w
From what premature age can babies survive
23w but mortality 60-70% and only 25% disability free
Prognosis is excellent beyond what premature gestation?
30-32w
Risk factors for prematurity?
Young maternal age Multiple pregnancy Infxn Maternal ‘illness’ (HTN, cervical incompetence, APN, smoking, alcohol, infection)
3 big risks of prematurity?
Hypothermia Hypoglycaemia Feeding difficulties