Fetal Respiratory Transition

Question 1

what weeks of development is pseudoglandular respiratory development?

Answer 1

5-15 weeks

Question 2

what weeks of development is canalicular respiratory development?

Answer 2

16-24 weeks

Question 3

what weeks of development is saccular respiratory development?

Answer 3

24-36 weeks

Question 4

what weeks of development is alveolar respiratory development?

Answer 4

36-38 weeks

Question 5

in what two stages of respiratory development are most preterm babies born in?

Answer 5

canalicular or saccular

Question 6

cortisol spikes in weeks 30-36 weeks gestation, what two benefits does this have on respiratory development?

Answer 6

enhances lung fluid clearance

increases surfactant production

Question 7

what can you give preterm babies to help with surfactant production?

Answer 7

antenatal glucocorticoid therapy

Question 8

what is the O2 sat in fetal pulmonary circulation?

Answer 8

55%

Question 9

which ventricle of the heart is in charge of 2/3 of fetal output and which is 1/3?

Answer 9

right ventricle is in charge of 2/3 and left 1/3

Question 10

what is the purpose of the fluid made by the lung in gestation?

Answer 10

to help expand the lung

Question 11

what cells make and secrete fluid in fetal lung?

Answer 11

the epithelial cells

Question 12

in the fetal circulation, what is providing the preload of the heart?

Answer 12

the umbilical vein

Question 13

after cutting the umbilical cord, now the preload of the heart is managed by what?

Answer 13

pulmonary venous return

Question 14

what molecule leads to the decrease in pulmonary vasculature resistance following birth?

Answer 14

NO

Question 15

what must happen to the fetal lung fluid following birth? what two things help this?

Answer 15

fetal fluid must be reabsorbed by epithelial cells…helped by uterine contractions and pressure gradients and the hormones

Question 16

what are the two mechanisms of fluid clearance from lungs?

Answer 16

exit via trachea

exit through epithelial cells and into interstitium like edema then out the lymphatic drainage

Question 17

how long does it take for the lung fluid to get cleared after birth?

Answer 17

4-6 hours

Question 18

why are babies blue right after birth? how long does it take for this to change?

Answer 18

babies are blue because the ductus arteriosus is still open and it takes about 10 minutes for this to close

Question 19

do we usually cut the cord right away now?

Answer 19

no…cutting the cord right away was done but was associated with negative effects

Question 20

what are the three negative effects of cutting cord immediately?

Answer 20

pulmonary vascular resistance is still high and pulmonary venous return is low and so preload is low

systemic vascular resistance will shoot up too

Question 21

what is respiratory distress syndrome?

Answer 21

inability to recruit alveoli due to low levels of surfactant

Question 22

give three reasons why pulmonary hypertension may remain in a new born?

Answer 22

respiratory distress syndrome
aspiration of meconium/pneumonia
pulmonary hypoplasia

Question 23

when pulmonary hypertension remains in a newborn, what ensues?

Answer 23

shunts stay open and are still R to L, baby remains in a hypoxic state

Question 24

what is TTN? what usually causes it?

Answer 24

transient tachypnea of the newborn

usually caused by slow fluid resorption in the lung