Paediatrics: Neonatal and Newborn Flashcards
What is jaundice?
A state of hyper-bilirubinaemia > 80 umol/L caused by pre-hepatic, hepatic or post-hepatic factors
When is neonatal jaundice normal and when is it worrying?
Jaundice presents > 24hrs post birth = physiological
Jaundice presents < 24hrs post birth = pathological (often haemolytic)
What is classed as prolonged jaundice and who is this most common in?
What are the other causes?
- Prolonged jaundice is > 14 d post birth or >21 d if premature
- Typically caused by breast feeding
Other causes:
- Hypothyroidism
- Biliary atresia (conjugated)
- Congenital infection (CMV, rubella)
- Galactosaemia
- UTI
What is the normal physiological mechanism of jaundice
RBC in neonates have much shorter life span than adults (70 vs 120 d) - RBC broken down to release Hb
Typically presents at 2 days and lasts 2 weeks
Explain how breast feeding causes jaundice
Breast milk contains enzymes that inhibit conjugation enzymes in the liver –> unconjugated jaundice
Peaks at 3-4 d resolves in 3 wks - 3 months
It is a primary cause of prolonged jaundice (i.e. jaundice lasting > 14 days or 21 days in prematurity)
What are the likely causes of jaundice < 24hrs birth, explain? (4)
(explain the overall process and the specific conditions that cause this)
Pathological - typically due to haemolytic process (pre-hepatic)
Mothers IgG Ab crosses placenta and reacts with foetal Ags on RBCs –> haemolysis –> rapidly increased levels of unconjugated bilirubin
- Rh haemolytic disease - mother is Rh-ve, baby is Rh+ve –> haemolysis
- ABO incompat - mother is O type, child is not –> mothers anti-A/B haemolysin IgG cross placenta and haemolyse RBC in infant
- G6PD deficiency - intermittent acute haemolytic episodes (X-linked recessive, heterozygous males, homozygous females)
- Spherocytosis - spherical shaped RBCs, haemolysis triggered in spleen, this is worsened following viral infection (autosomal dominant)
What is the possible danger of unconjugated bilirubin to the neonate?
Unconjugated bilirubin is not water soluble and cannot be wee’d out, therefore builds up causing yellowing of skin –> can cross BBB –> Kernicteris
What are the investigative findings of a haemolytic cause of jaundice?
Heinz bodies
+ve Coombs test (DAT)
What is the presentation of biliary atresia?
jaundice, pale chalky stools, yellow urine, hepato-splenomegaly
- conjugated bilirubin due to absence of intra/extrahepatic bile ducts
What is the main cause of neonatal hepatitis and what is the presentation?
a1-antitrypsin deficiency - hepatitis and prolonged neonatal jaundice, bleed (due to vitamin k def), portal HTN
What are the general symptoms of jaundice?
Yellow skin starts at head (eyes) –> trunk –> limbs
Sleepy, fatigue, poor feeding, vomiting
What are the key investigations for jaundice?
- Split bilirubin - measures conjugated _ unconjugated (>80 umol/l; >150 umol/l requires treatment)
- Coombs test
- Direct (detects Abs on RBCs) - +ve = haemolytic process
- Indirect (detects free Abs in serum) - done during pre-natal - Blanching test for skin
What is the primary treatment options for jaundice?
List any side effects and monitoring required that you can think of.
What is the treatment of biliary atresia?
What is the treatment of RhHD?
- Phototherapy (450nm blue light converts unconjugated bilirubin to conjugated to wee out)
- AE: fluctuation in temp, diarrhoea, dry skin, rash, eye damage, low mother bonding, poor appetite
- Monitor SBR every 4-6hrs when initiated; 6-10hrs when stabilised or falling; reduce intensity or stop when 50 below treatment line, if bilirubin rises after halted treatment most likely haemolytic process - Blood transfusion - blood removed from baby via central line, donor blood injected - must be twice childs blood volume (2x80ml/kg)
- Surgery if biliary atresia - Kasai procedure
- IV immunoglobulins 500mg/kg over 4hrs if haemolytic disease
What is the worrying complication of jaundice caused by haemolytic disease, breast feeding etc?
Uncojugated bilirubin is insoluble –> cannot be excreted via urine –> cross BBB and stains basal ganglia and brain stem –> kerniecterus (encephalitis)
Early - Jaundice, lethargy, poor feeding
Late - ^muscle tone, opisthotonos, seizures, coma
What is birth asphyxia?
What are the causes?
Lack of oxygen supply to baby in utero –> Oxygen deprived baby attempts to breathe –> primary apnoea (HR+BP maintained) –> gasping for breaths –> secondary apnoea (HR+BP fall) –> terminal
Causes respiratory depression (hypoxic, hypercapnia, resp acidosis) and CV depression (low CO + perfusion + met acidosis )
- Transiet (common) - transient blockage of oxygen supply due to uterine contractions
- Continuous (rare + dangerous) - complete cord prolapse (occludes blood supply), abruption (reduced gas exchange)
What are the symptoms of birth asphyxia and how can it be screened for?
Mild - hyperventilation, very sensitive to touch, starring eyes
Moderate - abnormal tone/posture, does not feed ± seizures
Severe - fluctuation between hypo/hypertonia, prolonged seizures, unresponsive to pain
Screen using APGAR score
7-10 is good
< 7 is worrying and needs medical intervention
What is the management of birth asphyxia?
Resuscitation - ABCDE
- Dry baby and maintain temperature
- Assess HR, RR, tone (APGAR)
- If gasping or not breathing - 5 ventilation breaths
- Reassess for chest movements
- If HR not improving or < 60bpm - compressions (3:1)
- Airway positioning and lung expansion (+ve pressure ventilation mask)
- Intubate
- if HR still not improving, consider DOPE
- Fluids to correct hypo - saline 0.9% with dextrose
- +ve inotrope or chrono trope agent
What are the complications of birth asphyxia?
Hypoxic ischaemic encephalopathy
Athetoid cerebral palsy
What is the clinical presentation of RhHD?
- Antenatal:
- Foetalis hydrops - severe oedema in 2 or more compartments (e.g. ascites, pericardial effusion, pleural effusion) - typically oedematous stiff legs
- Foetal anaemia - Post-natal:
- Foetalis hydrops
- Blueberry muffin rash -
- Jaundice (unconjugated) –> kernicterus
- Hepatosplenomegaly
What is the comments cause of AKI in children?
HUS
What are the key investigations for mothers ante-natally to determine risk of RhHD?
- INDCT - at booking visit (8wks) and 28 weeks
- +ve test indicates requirement for serial Ab titres - Serial Ab titres
- <4umol = unlikely
- 10-100umol = 10% risk
- >100umol = 70% risk of RhHD - Maternal blood group test
- +ve Rh-ve
- Raised anti-Rh titres
What can be given prophylactically for these mothers?
Anti-D IgG Ab to all mothers who are Rh-ve