Neonatal Physiology Flashcards
what is ductus arteriosus
connection between pumonary artery and aorta - to relieve circulatory load on lungs while RV strengthens
what is ductus venonosus
branch from umbilical vein that merges with IVC - delivers oxygenated blood
what is foramen ovale
hole between the atria of the heart
what happens to more of the structures of the foetal heart by birth
they become ligaments/foramen ovale closes
newborns have high/low O2 sats
low - 60-70%
when does the heart start beating
4th week
roughly, what is the blood pressure of a newborn baby <1hr old
70/44
heart rate of a newborn
120-160bpm
resp rate of a newborn
30-60/min
what is defined as bradycardia in newborns
<100bpm
physiological response to cold from baby
lipolysis of brown fat and heat production. Can’t shiver
what is brown fat
fat designed to keep you warm when you break it down. Has many more mitochondria. innervated by sympathetic fibres. Everyone has it just babies have more
tidal volume of baby
4-6ml/kg
true/false - newborns have higher blood gas partial pressures
false - actually around normal
pathophysiology of physiological jaundice
lots of RBC but an immature liver than can’t conjugate the bilirubin from breakdown fast enough –> build up of unconjugated bilirubin –> jaundice
after how long does physiological jaundice become a concern
> 2 weeks
main complication of newborn jaundice
kernicterus - unconjugated bilirubin crosses the BBB and deposits in brain. It’s neurotoxic
presentation of kernicterus
encephalopathy, poor feeding, seizures
late consequeuces of kernicterus
cerebral palsy, learning difficulties and sensorineural deafness
how long does physiological jaundice take to develop
24 hours
how long is it normal for babies not to pee for post-natally
24 hours
true/false - babies have more insensible water loss
true - immature skin and breathing
differences in neonatal kidneys
slower GFR
reduced Na reabsorption
less ability to concentrate or dilute urine
why do babies sometimes lose up to 10% of their weight
because fluid is shifting from interstitial to intravascular space –> diuresis
