neonatal medicine Flashcards
what proportion of babies need intensive care?
1-3%
explain the pathophysiology of hypoxic-ischaemic encephalopathy (HIE)
- gas exchange for the fetus is compromised
- reduced cardiac output
- cardiorespiratory depression
- brain injury
- brain death
- disability
- death
generally, what can lead to HIE?
any acute hypoxic events before/during labour/delivery
- failure of GE across placenta
- interrupted umbilical flow
- compromised fetal growth
- failure to breathe at birth
give examples of events that could cause failure of gas exchange across the placenta
- excessive/prolonged uterine contractions
- placental abruption
- ruptured uterus
give examples of events that could interrupt umbilical blood flow
- cord compression
- cord prolapse
- shoulder dystocia (compresses cord too)
give examples of events that could compromise fetal growth
- IUGR
- anaemia
what is the commonest neurodevelopmental disorder following HIE?
cerebral palsy
which nerves are injured in Erb’s palsy?
- C5
- C6
presentation of Erb’s palsy?
- affected arm lies straight
- limp arm
- pronated hand
- fingers flexed (waiter’s tip position)
a) what is the commonest fracture following shoulder dystocia?
b) what is the treatment and prognosis of this?
a) clavicle fracture
b) no treatment needed, excellent prognosis
what causes respiratory distress syndrome?
- surfactant deficiency
- reduced surface tension on the alveoli
what is the main risk factor for respiratory distress syndrome?
- being preterm!
- the more preterm the higher the risk
signs of respiratory distress syndrome?
- RR >60/min (tachypnoea, red flag sign!)
- laboured breathing
- chest wall recession
- expiratory grunting
- cyanosis (severe)
what are the 2 aims of the expiratory grunting in respiratory distress syndrome?
- to create positive airway pressure during expiration
- to maintain functional residual capacity
CXR sign in respiratory distress syndrome?
ground glass appearance
management of respiratory distress syndrome?
- raised ambient oxygen
- surfactant therapy via tracheal tube
- CPAP if needed
commonest heart defect in preterm neonate?
patent ductus arteriosus
presentation of patent ductus arteriosus in neonate?
- asymptomatic, or RDS:
- apnoea
- bradycardia
- low O2 sats
- bounding pulse
management of a symptomatic PDA?
- prostaglandin synthetase inhibitor
- e.g. indomethacin or ibuprofen
- surgical ligation if this fails
why are preterm infants at higher risk of infection?
IgG only crosses the placenta in the third trimester
complications of infection in preterm infants?
- bronchopulmonary dysplasia
- brain injury
- later disability
main GI complication in preterm infants?
- necrotising enterocolitis
- the more preterm they are the higher the risk is
which type of milk increases risk of necrotising enterocolitis?
cow’s milk
signs of necrotising enterocolitis?
- feed intolerance
- bile-stained vomit
- distended abdomen
- stools containing fresh blood
- shock (end stage)
X-ray findings in necrotising enterocolitis?
- distended bowel loops
- thickened bowel walls
- intramural gas
- bowel perforation (late)
management of necrotising enterocolitis?
- stop oral feeds
- broad-spectrum antibiotics (ampicillin, gentamicin)
- parenteral nutrition
- mechanical ventilation
long-term complications of necrotising enterocolitis?
- strictures
- malabsorption
- neurodevelopmental delay
a) risk factor for intraventricular haemorrhage?
b) when does it happen?
a) prematurity
b) <72h of life
disease progression of a large intraventricular haemorrhage?
- impairs drainage + reabsorption of CSF
- CSF builds up under pressure
- may resolve spontaneously
- OR progress to hydrocephalus
- anterior fontanelle gets tense
management of an intraventricular haemorrhage?
- symptomatic relief by removing CSF with LP
- ventriculoperitoneal shunt
long term complication of untreated intraventricular haemorrhage?
cerebral palsy
main cause of retinopathy of prematurity?
high conc of O2 administered
biggest risk factor of retinopathy of prematurity?
very low birthweight (<1500g)
management of retinopathy of prematurity?
- laser therapy
- intravitreal anti-VEFG therapy
define bronchopulmonary dysplasia
infants who still have an oxygen requirement aged 36 weeks
causes of bronchopulmonary dysplasia?
- delayed lung maturation
- artificial ventilation
- oxygen toxicity
- infection
CXR signs in bronchopulmonary dysplasia?
- areas of opacification
- cystic changes
management of bronchopulmonary dysplasia?
- CPAP or high-flow nasal cannula O2
- additional ambient O2 for months afterwards
which pathogens cause serious chest infection after bronchopulmonary dysplasia?
- RSV
- rhinovirus
cause of osteopenia of prematurity?
phosphate deficiency
explain why most newborns get jaundice
- marked release of Hb from broken down RBCs
- RBC lifespan in first few days is 70 days (vs 120 for us)
- hepatic metabolism of bilirubin not very efficient
underlying causes of neonatal jaundice?
- haemolytic anaemia
- infection
- inborn error of metabolism
- liver disease
how does kernicterus happen?
- unconjugated bilirubin gets deposited in basal ganglia
- causes encephalopathy
signs of kernicterus?
- lethargy
- poor feeding
- irritability
- increased muscle tone leading to arched back on lying down
- seizures
- coma
- death
complications post-kernicterus?
- choreoathetoid cerebral palsy
- learning difficulties
- sensorineural deafness
causes of haemolysis resulting in jaundiced neonate <24 hrs?
- rhesus haemolytic disease
- ABO incompatibility
- G6PD deficiency
causes of jaundice <2 weeks?
- physiological
- breast milk jaundice
- UTI
- haemolysis
- bruising
- polycythaemia
causes of unconjugated jaundice >2 weeks?
- physiological
- breast milk jaundice
- UTI
- haemolytic anaemia
- hypothyroidism
- pyloric stenosis
causes of conjugated jaundice >2 weeks?
- bile duct obstruction
- hepatitis
demographic for G6PD deficiency?
Mediterranean, Middle/Far Eastern or African babies
where is jaundice often missed?
- dark-skinned babies
- preterm babies
management of moderate jaundice in neonate?
- phototherapy
- blue-green light converts unconjugated bilirubin into harmless soluble stuff
- gets passed in urine
- given intensively where bilirubin is very high
side effects of phototherapy?
- hypothermia (undressed baby)
- bronzed skin
- macular rash
management of severe jaundice in neonate?
- exchange transfusion
- blood removed by aliquots via arterial line / umbilical vein
- replaced with donor blood via umbilical vein
key differential for jaundice in neonate >2 weeks old?
- biliary atresia
- bilirubin here is CONJUGATED
- needs to be managed promptly
when should breast milk jaundice be cleared up by?
4-5 weeks of age
signs of respiratory distress?
- tachypnoea >60 breaths/min
- laboured breathing with recession
- nasal flaring
- expiratory grunting
- head bobbing (severe)
- cyanosis (severe)
pulmonary causes of respiratory distress in term infant?
- transient tachypnoea of the newborn (common)
- meconium aspiration
- pneumonia
- RDS
- pneumothorax
- milk aspiration
- airway obstruction
- diaphragmatic hernia
non-pulmonary causes of respiratory distress in term infant?
- congenital heart disease
- HIE
- severe anaemia
- metabolic acidosis
when does meconium pass?
- 20% pass it before birth
- others pass it during delivery
how is meconium aspirated?
asphyxiated newborn could choke on it when gasping for air
risk factors for neonatal pneumonia?
- PROM
- chorioamnionitis
- low BW
risk factors for milk aspiration?
- preterm babies
- GOR (often follows bronchopulmonary dysplasia)
- cleft palate
- neuro disorder
presentation of diaphragmatic hernia?
- many are picked up on antenatal USS
- respiratory distress
- not responsive to resuscitation
CXR in diaphragmatic hernia?
- most are left-sided
- left bowel loops up in the thorax
management of diaphragmatic hernia?
- large nasogastric tube
- suction applied (stops the lifted bowel from getting any bigger)
- then surgery
main underlying cause of diaphragmatic hernia?
pulmonary hypoplasia (high mortality if true)
features of neonatal sepsis?
- fever OR hypothermia
- poor feeding
- vomiting
- apnoea
- bradycardia
- respiratory distress
- abdominal distension
- jaundice
- neutropenia
- hypoglycaemia OR hyperglycaemia
- shock
- irritability
- seizures
- lethargy
added signs of sepsis seen only in meningitis?
- tense, bulging fontanelles
- head retraction
commonest pathogen in neonatal infection >48h of life?
staph epidermis
sources of infection >48h of life?
usually environmental:
- indwelling central catheters (TPN)
- tracheal tubes
- any other invasive stuff
- poor hand hygiene of others handling baby
what % of pregnant women carry GBS?
10-30%
risk factors for GBS infection in newborn?
- preterm birth
- PROM
- maternal fever during labour
- chorioamnionitis
- past Hx of infected infant
prophylaxis of GBS infection?
mothers at risk of GBS are offered IV antibiotics
age of presentation with GBS infection?
- early onset = straight after birth
- late onset = 3m old
which foods may contain listeria?
- unpasteurised milk
- soft cheese
- undercooked meat
- pate (veg or non veg!)
presentation of listeria infection in mother?
- mild flu-like illness
- caused by the bacteraemia
features of listeria infection in the neonate?
- meconium staining the liquor
- widespread rash
- septicaemia
- pneumonia
- meningitis
signs of gonococcal eye infection in neonate?
- purulent discharge
- conjunctivitis
- swollen eyelids
- presents <48h of life
- blindness (late)
urgent investigation in gonococcal eye infection?
gram stain the discharge
main difference between gonococcal and chlamydia eye infection?
chlamydia usually presents a bit later (1-2 weeks old)
investigation in chlamydia eye infection?
immunofluorescent staining
management of chlamydia eye infection?
2 weeks of oral erythromycin
presentation of neonatal herpes?
- lesions on skin or eye
- encephalitis
prophylaxis for infant born to hep-B positive mother?
immediate vaccination against it to stop vertical transmission
risk factors for hypoglycaemia <24h of life?
- IUGR
- maternal DM
- large for gestational age
- hypothermic
- polycythaemic
symptoms of neonatal hypoglycaemia?
- jitteriness
- irritability
- apnoea
- lethargy
- drowsiness
- seizures
prevention of hypoglycaemia?
- early and frequent feeding
- regular blood glucose monitoring for at-risk babies
definition of hypoglycaemia in neonate?
blood glucose <2.6 mmol/l
