Neonatology Flashcards
what are the three shunts in the foetal circulation?
- ductus venosus
- foramen ovale
- ductus arteriosus
role of ductus venosus
passes bloods from placenta via the umbilical vein through the liver to the IVC
role of the foramen ovale
passage of blood from right to left atria
role of ductus arteriosus
passes blood from the right ventricle to the aorta using the pulmonary artery
what blood does the umbilical vein carry?
oxygenated
what blood do the umbilical arteries carry?
deoxygenated
what preparations for birth are made in the 3rd trimester?
surfactant production (type II pneumocytes)
accumulation of glycogen
accumulation of brown fat
accumulation of subcutaneous fat
swallowing of amniotic fluid to grow lungs
preparations during labour/delivery
catecholamines/ cortisol increases
crying absorbs lung fluid into lymphatics
vaginal delivery squeezes lungs
what happens to the circulation when birthed
pulmonary vascular resistance drops
lungs expand
systemic vascular resistance drops
prostaglandins close ducts
what does the ductus venosus become?
ligamentum teres
fate of foramen ovale
closes
fate of ductus arteriosus
becomes ligamentum arteriosus
respiratory complications in the new-born?
PPHN meconium aspiration TTPN RDS Potter's syndrome pneumothorax pneumonia
other complications in the new-born
diaphragmatic hernia HIE fistula PDA intraventricular haemorrhage NEC ROP
what is PPHN?
patent PDA and PFO so pulmonary vascular resistance fails to drop
diagnosis of PPHN
pre and post-ductal saturation as artery that supplies upper right limb leaves aorta before PDA (high oxygenation)
positive result if more than 3% difference
what can cause TTPN
C-section has no squeezing of lungs so fluid is not absorbed
presentation of TTPN
tachypnoea and grunting within first 6 hours
management of TTPN
screen for infection
self-limiting and transient
what causes RDS
lack of surfactant
pre-terms usually
management of RDS
maternal steroids
surfactant
what is Potter’s syndrome?
renal agenesis
why is Potter’s syndrome involved with the lungs?
no urine is produced so no amniotic fluid is swallowed leading to pulmonary hypoplasia
what is NEC (necrotising enterocolitis)?
inability to handle milk and bacteria enters the blood
what is ROP (retinopathy of prematurity)?
abnormal blood vessel growth in the eye
what adaptations are made in the first few hours of life?
thermoregulation
glucose homeostasis
how is heat lost?
radiation
convection
conduction
evaporation
why do newborns lose heat rapidly?
large SA to volume ratio
can babies shiver?
no so they breakdown stored fat for heat
what do babies use as brain fuel?
ketones
what happens to glucose homeostasis at birth?
changes from a continuous infusion to intermittent bolus
causes of hypoglycaemia in the new-born
increased demand (unwell) low stores (small/ premature) inappropriate endocrinology e.g. GDM or hyperinsulinaemia (mother on beta blockers)
what causes physiological jaundice?
foetal Hb is broken down but the conjugating pathway is immature so there is an increase in unconjugated bilirubin
when does physiological jaundice occur?
2-5 days
reasons for pathological jaundice?
kernicterus
biliary atresia
what is term?
37 weeks gestation
what is post-term?
beyond 41 weeks
when is pre-term?
under 37 weeks
what scale is used to assess progression?
APGAR score
what is a normal APGAR score?
above 8
resuscitation in children?
airway is more neutral (not head tilt, chin lift)
therapeutic cooling in cerebral palsy
types of cerebral palsy
ataxic paraplegic diplegic hemiplegic dyskinetic quadriplegic
