Neonataology Flashcards
When does the CVS start to develop?
End of third week
When does the heart start beating?
End of fourth week
What is the critical period for development of the heart?
20 to 50th day after fertilisation
What is the ductus venosus?
Vein that comes off of the umbilical vein that shunts a portion of oxygenated blood coming from the placenta directly into the IVC (bypassing the liver)
What is the foramen ovale?
Shunt between the R and L atrium - allowing blood to bypass the pulmonary circulation
What is the patent ductus arteriosus?
Connects pulmonary artery to the descending aorta - allowing blood to bypass the pulmonary circulation
What is normal SaO2 in foetal body?
60-70%
What are the functions of the ductus arteriosus?
Protects lungs against circulatory overload
Allows the R ventricle to strengthen
Carries low oxygen saturated blood
How is blood flow regulated in the ductus venosus? What kind of blood is mostly carried in the ductus venosus?
Oxygenated blood regulated via sphincters
What do the foramen ovale and ductus arteriosus become after birth?
Ligamentum arteriosum and fossa ovalis
What is the normal BP of a 1h old?
70/44
What is the normal BP of a 1 day old?
70+/-9/42+/-12
What is the normal BP of a 3 day old?
77+/-12/49+/-10
What is the normal RR of a newborn?
30-60m
Periodical breathing
What is the normal HR of a newborn?
120-160bmp
Tachycardia is over 160
Bradycardia is <100
Why are newborns purely reliant on metabolic production of heat?
Inability to shiver
What does cold stress lead to in babies?
Lipolysis and heat production
Brown fat well innervated by sympathetic neurons
Define radiation of heat
Heat dissipated to colder objects
Define convection of heat
Heat loss by moving air
Why is evaporation of heat important in newborns?
We are born in water
What is conduction?
Heat loss to the surface on which the baby lies
A newborn does not pass urine for 24 hours - what does this mean?
It is normal
Weight loss of up to what is normal in the newborn? What is the weight loss due to?
10%
Due to shift of interstitial fluid to intravascular
Diuresis
When does physiological jaundice occur?
Day 2-3 of life
Disappears within 7-10 days of life in term infants (up to 21 in prem babies)