Neonatology

Question 1

When does the heart begin to develop?

Answer 1

End of 3rd week

Beats at end of 4th week

Question 2

In foetal circulation where does oxygenated blood come from

Answer 2

From placenta via umbilical vein to ductus venosus- which shunts oxygenated blood to IVC bypassing the liver

Question 3

Fucntion of foramen ovale?

Answer 3

Shunts blood from right atrium to left atrium

Question 4

Function of patent dutus arteriosus

Answer 4

Shunts blood from pulmonary artery to aorta

Protects lungs against circulatory overload

Allows the right ventricle to strengthen

Carries low O2 saturated blood

Question 5

Saturations SaO2 in foetal body

Answer 5

60-70%

Question 6

Function of Ductus venosus

Answer 6

Connects the umbilical vein to the IVS

Question 7

Normal blood pressure in a newborn

Answer 7

1hour age 70/44
1 day 70(+/-9)/42(+/-12)
3 days 77 (+/-12)/ 49 (+/-10)

Question 8

Normal rr and hr in newbornes

Answer 8

RR- 30-60/min
HR- 120-160b/min

Tachycardia >160b/min
Bradycardia <100b/min

Question 9

How do newborns thermoregulate

Answer 9

Lack shivering thermogenesis
Use Brown fat onnervated by sympathetic neurons
Cold stress leads to lipolysis and heat production

Question 10

How do newborns lose heat

Answer 10

Radiation,
Convection,
Evaporation,
Conduction

Question 11

Noninvasive ways to measure newborn breathing

Answer 11

Blood gas
PaCo2 (5-6kPa)
PaO2 (8-12kPa)

Trans-cutaneous pCO2/ O2 measurement

Question 12

Invasive wats to measure newborn breathing

Answer 12

Capnography
Titdal volume 4-6ml/kg
Minute ventilation (tidal volume ml/kg x RR
Flow-volume loop

Question 13

When does physiological jaundice appear in newborns

Answer 13

DOL 2-3
Disappears within DOL 7-10 or 21 in premature

10% breast fed jaundice at 30 DOL

Question 14

What can high concentrations of bilirubin do to the brain?

Answer 14

Irreversible changes- kernicterus

Question 15

How much weight is normal for a new born to lose and why?

Answer 15

10%

Due to:

• shift of interstitial fluid to intravascular
• Diuresis

Question 16

Why is there increased loss of fluids in premature infants

Answer 16

Less fat in body
Causing increased loss through kidney 
-slows GFR
-Reduces Na reabsorption
-Decreased ability to concentrate or dilute urine 

Increased insensible water loss
-Via immature skin and breathing

Question 17

Why does physiological anaemia of newborn occur

Answer 17

Rbc production is 10% of in uterus DOL 7
So babies are born with Hb 15-20g/l
And at week 10 Hb 11.4g/l

There is an increase production of erythropoetin
And at week 20 Hb is 12.0 g/l

Question 18

Causes of anaemia in premature newborns

Answer 18

Reduced erythropoesis
Infection
Blood letting