Neonatal lecture

Question 1

risk factors for RDS

Answer 1

IDM
fetal asphyxia
multiple gestations
males>females
caucasian> african american

Question 2

embryonic stages of lung development

Answer 2

0-5 weeks

-proximal airways: bronchi

Question 3

pseudoglandular stage

Answer 3

6-16 weeks

Question 4

canalicular stage

Answer 4

17-24 weeks

Question 5

terminal sac stage

Answer 5

25-37 weeks

Question 6

alveolar stage

Answer 6

37 weeks and on

Question 7

when are type II cells present?

Answer 7

20 weeks (canalicular period)

Question 8

prognosis of RDS is directly related to

Answer 8

gestational age and birth weight

Question 9

treatment of RDS

Answer 9

• resuscitation by skilled team
• intratracheal administration of exogenous surfactant
• meticulous neontal care (thermal neutrality, infection control, nutrition fluids)
• assisted ventilation

Question 10

prevention of RDS

Answer 10

• reduce premature births
• predict at risk pregnancies and treat with steroids if go into premature labor
• prophylactic/early treatment of high risk infants (<30 weeks gestation) with exogenous surfactant in delivery room

Question 11

laboratory results in RDS

Answer 11

hypoxia, hypercarbia, acidosis

Question 12

radiographic findings in RDS

Answer 12

granular densities appear within hours of birth

“ground glass” appearance

Question 13

clinical presentation of RDS

Answer 13

premature infants

• tachypnea, central cyanosis, labored breathing: retractions, flaring and grunting
• auscultations may reveal fine rales

Question 14

why do babies grunts?

Answer 14

trying to increase pressure so alveoli don’t collapse

Question 15

why do retractions happen?

Answer 15

because when the baby breathes the lungs won’t open and so the chest wall collapses

Question 16

pathophysiology of RDS

Answer 16

poor alveoli stability->right to left shunting of blood->reduced effective pulmonary blood flow-> reduced effective pulmonary blood flow->pulmonary edema->hyaline membrane development-> reduced lung compliance

Question 17

pathogenesis of RDS

Answer 17

• deficient surfactant at air fluid interface of alveoli in immature lungs
• problem with secretion not with synthesis
• deficiency leads to areas of atelectasis
• other alveoli over-distended and epithelial damage occurs and proteins leak into the airspace further impairing surfactant function

Question 18

what does surfactant do?

Answer 18

lowers surface tension to near zero (as more water is displaced from the monolayer) and allows for the smallest of alveoli to remain distended at full deflation
-thus surface area is maximized for gas exchange throughout the respiratory cycle