peds 1

Question 1

pre-term

Answer 1

prior to 37 weeks gestational age

Question 2

neonate

Answer 2

1-28 days of life

Question 3

infant

Answer 3

28 days - 1 year

Question 4

child

Answer 4

> 1 year

Question 5

most significant part of transition occurs within the first

Answer 5

24-72 hours after birth with adaptive changes in all organ systems

Question 6

4 adaptive changes

Answer 6

establish FRC,
Convert circulation,
recover from birth asphyxia,
maintain core temperature

Question 7

Fetal hgb totals

Answer 7

70-90%

Question 8

Fetal hgb shifts oxyhmoglobin dissociation curve to

Answer 8

left(increased o2 loading in the lungs/placenta, decreased o2 unloading at tissues)

Question 9

hgb full term neonate

Answer 9

18-20g/dl (o2 unloading insufficient after birth)

Question 10

fetal lung dev.-primitive lung buds develop from foregut

Answer 10

4 weeks

Question 11

fetal lung dev. - branching of bronchial tree complete to 28 divisions, no further formation of cartilaginous airways

Answer 11

16 weeks

Question 12

fetal lung dev. - primitive alveoli (saccules) and type II cells present; surfactant detectable; survival possible with artificial ventilation

Answer 12

24 weeks

Question 13

fetal lung dev. - capillary network surrounds saccules; unsupported survival

Answer 13

28-30 weeks

Question 14

fetal lung dev. - true alveoli present, roughly 20 million at birth

Answer 14

35-40weeks

Question 15

fetal lung dev. - PaO2 rises as R to L mechanical shunts close

Answer 15

birth-3months

Question 16

fetal lung dev. - rapid increase in alveoli 350million at age 6

Answer 16

to 6 years

Question 17

“guppy breathing in utero” present from ___ weeks gestation, ____% of the time at a rate of __ breaths/min

Answer 17

30 weeks, 30%, 60 breaths/min

Question 18

traditional view of adaption of breathing vs fetal lamb studies

Answer 18

traditional(hypoxemia, hypercarbia, and acidosis of birth asphyxia stimulates chemoreceptors that produce gasping followed by rhythmic breathing. lamb(studies shown total denervation of carotid, aortic, and peripheral chemoreceptors does not alter fetal breathing or initiation)

Question 19

What changes are responsible for the decrease in PVR

Answer 19

Increase in PO2,
Decrease in PCO2,
change in pH

Question 20

Decrease in PVR, _____ pulmonary blood flow

Answer 20

increases

Question 21

Current adaption of breathing view

Answer 21

rhythmic breathing occurs with clamping of the umbilical cord and increasing O2 tensions from air breathing

Question 22

What is the primary event of the respiratory system transition?

Answer 22

Initiation of Ventilation

changes alveoli from a fluid filled to and air filled state

Question 23

Negative pressure infant must generated to inflate the lungs

Answer 23

-70cm H2O

Question 24

neonate FRC approx

Answer 24

25-30mL/kg

Question 25

why are neonate and infant lungs prone to collapse?

Answer 25

weak elastic recoil, weak intercostal muscles, intra-thoracic airways collapse during exhalation

Question 26

_____ closing volume encroaches upon FRC - _____ airway closure begins at volumes at or ______ FRC leading to lung collapse and V/Q mismatch

Answer 26

High, small, above

Question 27

Why don’t infants have lung collapse all of the time? Infants terminate the expiratory phase of breathing before reaching their true FRC which results in intrinsic PEEP and a higher FRC. When anesthetized, however, this protective mechanism is abolished. The opposing tonic state of the intercostal muscles is overridden and atelectasis occurs. The moral of this story

Answer 27

***PEEP of 5cm H2O can help maintain FRC/lung inflation in the neonate during anesthesia***

Question 28

respiratory control is poorly developed in neonates. The system is normal by ___ weeks of age, but likely remains ______ for some time, especially in preterm babies

Answer 28

3-4 weeks, | immature

Question 29

how do newborns respond to hyper-carbia

Answer 29

increasing ventilation, but the slope of the response curve is decreased

Question 30

what depresses neonate's response to CO2?

Answer 30

hypoxia

Question 31

biphasic response to hypoxia

Answer 31

initial hyperpnea followed by depression of respiration in about 2min

Question 32

***Initial hyperpneic response is abolished by ______ and low levels of _________ gases

Answer 32

hypothermia, | anesthetic

Question 33

by 3 weeks of age, hypoxia produces sustained

Answer 33

hyperventilation

Question 34

_____ is a common response and a real danger, especially in preterm infants

Answer 34

apnea

Question 35

respiratory pauses exceeding ___ sec or those accompanied by bradycardia or cyanosis

Answer 35

Apnea of infancy | 20 seconds

Question 36

Hypoxia causes PROFOUND ______ in babies

Answer 36

bradycardia

Question 37

Increased work of breathing=

Answer 37

FATIGUE

Question 38

Contributing factors for apnea of infancy

Answer 38

increased O2 consumption 6mL/kg, decreased FRC, increased closing volume

Question 39

where does gas exchange in the fetus

Answer 39

the placenta

Question 40

in the fetus lungs require what percentage of CO

Answer 40

5-10%, only nutrient flow

Question 41

fetal intracardiac and extracardiac shunts exist to

Answer 41

minimize blood flow to the lungs while maximizing flow/O2 delivery to organ systems

Question 42

Name of fetal shunts

Answer 42

ductus venosus, foramen ovale, ductus arteriosus

Question 43

_______ blood travels the _______ aorta to the _______ arteries to the placenta(very low resistance to flow), ______ blood returns via the umbilical vein (PO2 35mmHg), ductus _____ diverts approx. ___% of blood away from the liver into the IVC then to the _____

Answer 43

``` Deoxygenated, descending, umbilical, oxygenated, venosus, 50, RA ```

Question 44

_____ blood directed across the foramen ovale, fed to LV, ejected to aorta feeding coronary and cerebral circulations

Answer 44

O2 rich

Question 45

SVC and hepatic venous flow delivered to the ____

Answer 45

RV

Question 46

fetal circulation pulmonary vascular resistance is

Answer 46

HIGH!!!

Question 47

____ output is delivered across the ductus arteriosus which connects the ___ to the ______ ________

Answer 47

RV, PA, descending aorta