Neonatal Core Conditions

Question 1

What is Jaundice?

Answer 1

Jaundice is the yellow colouring of skin and sclera caused by the accumulation of bilirubin in the skin and mucous membranes.

Question 2

How common is neonatal jaundice?

Answer 2

60% of term infants and 80% of preterm infants.
10% of breast fed babies are jaundiced at 1 month.

Question 3

What is physiological jaundice?

Answer 3

Normal phenomenon in neonates, with no underlying pathology. High levels of unconjugated bilirubin. Presents in the first 2-7 days of life and usually resolves by 10 days.

Question 4

What causes physiological jaundice?

Answer 4

-Marked physiological release of Hb from the breakdown of RBCs due to the high Hb conc at birth
-RBC lifespan of newborn infants (70 days) is much shorter than adults (120 days)
-Hepatic bilirubin metabolism is less efficient in the first few days of life

Question 5

When is jaundice always pathological?

Answer 5

In the first 24 hours and if conjugated.

Question 6

What are the main causes of jaundice in the first 24 hours?

Answer 6

-Neonatal sepsis
-Rhesus haemolytic disease
-ABO haemolytic disease
-Hereditary spherocytosis
-Glucose-6-phosphate dehydrogenase (G6PH) deficiency

Question 7

What are the key causes of neonatal jaundice?

Answer 7

Increased production of bilirubin:
-Haemolytic disease of the newborn
-ABO incompatibility
-Haemorrhage
-Intraventricular haemorrhage
-Cephalo-haemorrhage
-Polycythaemia
-Sepsis and DIC
G6PD deficiency
Decreased clearance of bilirubin:
- Prematurity (immature liver)
-Breast milk jaundice
-Neonatal cholestasis
-Extrahepatic biliary atresia
-Endocrine disorders (hypothyroid and hypopituitary)
-Gilbert syndrome
-Neonatal hepatitis

Question 8

When is jaundice classed as prolonged?

Answer 8

More than 14 days in full term. More than 21 days in premature babies.

Question 9

What are key causes of prolonged jaundice?

Answer 9

-Biliary atresia
-Hypothyroidism
-Galactosaemia
-Haemolytic anaemia
-Infection (particularly UTI)
-Breast milk jaundice
-Prematurity
-High GI obstruction e.g. pyloric stenosis
-Congenital infections e.g. CMV, toxoplasmosis

Question 10

How should jaundice be investigated?

Answer 10

Bilirubin:
- Transcutaneous bilirubinometer (TCB) in >35/40 gestation and >24hrs old.
-Serum bilirubin if <35/40 gestation, <24 hours old or TCB >250 ymol/L
Further:
-FBC (for Hb and haematocrit) anad blood film
-Direct antiglobulin test (Coombs’ test)
-TFTs
-LFTs
-U&Es
-Infection screen: blood, urine, CSF. Consider TORCH screen.
-G6PD levels

Question 11

What is Gilbert’s syndrome?

Answer 11

Autosomal recessive disorder with reduced UGT enzyme ability to conjugate bilirubin, results in mild episodes or jaundice throughout life in response to certain triggers

Question 12

What is Glucose-6-phosphate dehydrogenase (G6PD) deficiency?

Answer 12

X-linked recessive condition where lack of G6PD makes RBCs susceptible to oxidative damage and haemolysis. Can cause severe neonatal jaundice.

Question 13

What is hereditary spherocytosis?

Answer 13

Inherited disease where defects in RBC skeletal proteins cause RBCs to assume a spherical shape with a reduced lifespan.

Question 14

What is biliary atresia?

Answer 14

Congenital inflammatory disease of unknown cause. Results in complete obliteration of the extra-hepatic bile ducts after birth. Presents with prolonged conjugated jaundice, pale stools and dark urine.

Question 15

How is neonatal jaundice managed?

Answer 15

Plot total bilirubin levels on treatment threshold chart. 2 options:
- Phototherapy - converts unconjugated bilirubin into isomers which are excreted in bile and urine without requiring conjugation in liver. Remove all clothing and use blue-light. Rebound level should be measured in 12-18 hrs to ensure levels haven’t risen above threshold levels.
- Exchange transfusion - not very common as high rate of complications. Swap the baby’s blood with donor blood. Required for dangerously high levels of bilirubin or if signs of bilirubin encephalopahy.

Question 16

What is bilirubin encephalopathy (Kernicterus)?

Answer 16

Occurs with high levels of unconjugated bilirubin as can cross the blood-brain barrier. Accumulates in brain and is neurotoxic. Presents with lethargy, hypotonia and poor suck reflex (Floppy, drowsy, poor feeding). Progresses to hypertonia, opisthotonos, fever, seizures and high-pitched cry. Can lead to permanent damage causing cerebral palsy, learning disability and deafness. Rare due to effective treatment of jaundice.

Question 17

When does a baby become clinically jaundiced?

Answer 17

At about 80 ymol/l

Question 18

What are the causes of hypoxic ischaemic encephalopathy?

Answer 18

• Failure of gas exchange across the placenta: excessive or prolonged uterine contractions, placental abruption, ruptured uterus, placenta previa
  -Interruption of umbilical blood flow - cord compression including shoulder dystocia, cord prolapse
  -Inadequate maternal placental perfusion: maternal hypotension or hypertension
  -Compromised fetus - intrauterine growth restriction, anaemia
  -Failure of cardiorespiratory adaptation at birth - failure to breath
  -Intrapartum haemorrhage

Question 19

What are the stages of HIE?

Answer 19

Sarnat staging:
-Mild (grade 1) - poor feeding, general irritability and hyper-alert. Resolves within 24 hrs. Normal prognosis.
-Moderate (grade 2) - poor feeding, lethargic, hypotonic and seizures. Can take weeks to resolve, 40% develop cerebral palsy.
-Severe (grade 3) - reduced consciousness, apnoeas, flaccid and reduced/absent reflexes, multiorgan failure. 50% mortality, 90% develop cerebral palsy

Question 20

How can HIE be identified?

Answer 20

aEEG (amplitude-integrated electroencephalogram) - detects abnormal background brain activity to confirm early encephalopathy and identify seizures.

Question 21

How is HIE treated?

Answer 21

• Respiratory support, treatment of seizures, nutrition, acid base balance, circulatory support.
  -Mild hypothermia. Cool down to 33-34 degrees (using cooling blanket and cooling hat, measured rectally) for 72 hours. Start cooling within 6 hours of birth.

Question 22

What is the key complication of HIE?

Answer 22

Cerebral palsy

Question 23

What is classed as premature?

Answer 23

Birth before 37 weeks gestation

Question 24

What are the WHO stages of preterm delivery?

Answer 24

-Extreme preterm: before 28 wks
-Very preterm: 28-32 wks
-Moderate to late preterm: 32-37 wks

Question 25

What are the risk factors for prematurity?

Answer 25

-Previous preterm delivery
-Multiple pregnancy
-Smoking and illicit drug use in pregnancy
-Being under or overweight in pregnancy
-Early pregnancy (within 6 months of previous pregnancy
-Problems involving cervix, uterus or placenta, including infection
-Maternal co-morbidities e.g. diabetes and hypertension
-Physical injury/trauma

Question 26

How is prematurity managed antenatally?

Answer 26

-Tocolysis with nifedipine - CCB that suppresses labour
-Maternal corticosteroids - reduce neonatal morbidity and mortality
-IV magnesium sulphate - helps protect baby’s brain
-Delayed cord clamping or cord milking

Question 27

What are the complications associated with prematurity?

Answer 27

Respiratory:
-Respiratory distress syndrome
-Surfactant deficient lung disease, Chronic lung disease/Bronchopulmonary dysplasia, recurrent apnoea.
-Pneumothorax
Cardiovascular:
-Hypotension
-Perfusion abnormalities, PDA, anaemia of prematurity
Neurological:
-Intraventricular haemorrhage
-Seizures, post haemorrhagic ventricular dilatation, neurodevelopmental delay, cerebral palsy.
GI:
-Necrotising enterocolitis
-Immature gut causing feed intolerance
-Inguinal hernias
Renal/electrolyte:
-Immature renal function
Metabolic:
-Jaundice
-Hyperglycaemia, hypoglycaemia, inborn errors of metabolism
Infection/immune:
-Sepsis (increased risk of infection)
-Immature skin barrier
Others:
-Immature thermoregulation
-Retinopathy of prematurity

Question 28

What is respiratory distress syndrome?

Answer 28

Deficiency of surfactant, which lowers surface tension. Occurs below 32 weeks. Inadequate surfactant leads to high surface tension wtihin alveoli. This leads to atelectasis (lung collapse), as it is more difficult for the alveoli and the lungs to expand. This leads to inadequate gaseous exchange, resulting in hypoxia, hypercapnia and respiratory distress.

Question 29

What are the clinical signs of RDS?

Answer 29

At delivery or within 4 hours of birth:
-Tachypnoea over 60 breaths/minute
-Increased work of breathing, with chest wall recession and nasal falring
-Expiratory grunting to try and create positive airway pressure during expiration and maintain functional residual capacity
-Cyanosis if severe

Question 29

What are the clinical signs of RDS?

Answer 29

At delivery or within 4 hours of birth:
-Tachypnoea over 60 breaths/minute
-Increased work of breathing, with chest wall recession and nasal falring
-Expiratory grunting to try and create positive airway pressure during expiration and maintain functional residual capacity
-Cyanosis if severe

Question 30

What does a CXR look like in RDS?

Answer 30

diffuse granular or ‘ground glass’ appearance

Question 31

What is the antenatal management of RDS?

Answer 31

Antenatal steroids (e.g. dexamethasone) given to mothers with suspected or confirmed preterm labour to increase the production of surfactant and reduce the incidence and severity of RDS in the baby.

Question 32

What is the management of RDS in the newborn?

Answer 32

-Intubation and ventilation to assist breathing if severe
-Endotracheal surfactant
-CPAP via a nasal mask to help keep lungs inflated
-Sup O2 to maintain sats between 91 and 95%

Question 33

What are the complications of RDS?

Answer 33

-Pneumothorax
-Infection
-Apnoea
-Intraventricular haemorrhage
-Pulmonary haemorrhage
-Necrotising Enterocolitis
-Chronic lung disease
-Retinopathy of prematurity
-Neurological, hearing and visual impariment

Question 34

What is the Apgar score?

Answer 34

Assesses the health of a newborn baby
-Appearance/Colour
-Pulse
-Grimace/ reflex irritability
-Activity/ muscle tone
-Respiratory effort
Score 7-10 is good. 0-3 is very low, 4-6 is moderate low.
Assess at 1 and 5 mins of age

Question 35

What is a cephalhaematoma?

Answer 35

Haematoma from bleeding below the periosteum, confined within the margins of the skull sutures, usually involves the parietal bone. Caused by tearing of vessels during birth. Resolves over several weeks.