Fetal Lung Development & Gas Exchange

Front 1

Stage of Lung Development: Embryonal
Time of Occurence: Significance:

Back 1

Embryonal
Day 26 - Day 52
Development of trachea and major bronchi

Front 2

Stage of Lung Development: Pseudoglandular
Time of Occurence:
Significance:

Back 2

Pseudoglandular
Day 53 - Week 16
Development of remaining conduction airways

Front 3

Stage of Lung Development: Canalicular
Time of Occurence:
Significance:

Back 3

Canalicular
Week 17 - Week 26
Development of vascular bed and framework of respiratory acini

Front 4

Stage of Lung Development: Saccular
Time of Occurence:
Significance:

Back 4

Saccular
Week 26 - Week 36
Increased complexity of saccules; pneumocytes are able to produce & use surfactant

Front 5

Stage of Lung Development: Alveolar
Time of Occurence:
Significance:

Back 5

Alveolar
Week 36 - Term
Development of the Alveoli

Front 6

Give the stages of lung development in chronological order

Back 6

embryonal
pseudoglandular
canalicular
saccular
alveolar

Front 7

The major airways are developed by the end of which stage?

Back 7

Embryonal

Front 8

What stage of lung development does the diaphragm develop?

Back 8

Embryonal

Front 9

At what age does the alveoli stop increasing in number?

Back 9

By age 8; but will continue to increase in size until the chest wall growth is complete

Front 10

When does most of the postnatal formation of alveoli in the infant occur?

Back 10

Mostly in the first year and a half of life

Front 11

At what stage of lung development is it possible for a premature infant to survive?

Back 11

During the Canalicular Stage. Around the 22 to 24th weeks.

Front 12

What does Tocolysis mean?

Back 12

Tocolysis is the process of stopping labor, acheived by a delivery of drugs to the mother

Front 13

What is Placental previa?

Back 13

Placenta previa is when implantation of the placenta occcurs in the lower portion of the uterus

Front 14

What are some of the forms of placental previa?

Back 14

1. Low implantation
2. Partial
3. Total/complete

Front 15

Descride Low implantation placental previa

Back 15

Low implantation placental previa - the placenta occupies the lower portion of the uterus but doen't cover the cervical opening

Front 16

Describe Partial placental previa

Back 16

Partial placental previa - a portion of the cervical opening is covered by the placenta

Front 17

Descrive Total/Complete placental previa

Back 17

Total/Complete placental previa - the entire cervical opening is covered by the placenta

Front 18

What is Parturition?

Back 18

Parturition is the process of giving birth

Front 19

What are the five distinct events of Parturition?

Back 19

1. Rupture of the membranes
2. Dilation of the cervix
3. Contraction of the uterus
4. Separation of the placenta
5. Shrinking of the uterus

Front 20

What is the first stage of Normal Labor and Delivery?

Back 20

First - Onset of regular contractions to full dilation and effacement of the cervix?

Front 21

What is the second stage of normal labor and delivery?

Back 21

Second - Full dilation and effacement of the cervix to delivery of the fetus

Front 22

What is the thrid stage of normal labor and delivery?

Back 22

Delivery of the fetus to delivery of the placenta

Front 23

What does effacement mean?

Back 23

Effacement is the stretching and thinning of the cervix

Front 24

In terms of labor and delivery, what does the term dilation mean?

Back 24

Dilation - the widening of the cervix (fully dilated at 10 cm)

Front 25

What does the term presentation mean when speaking of labor and delivery?

Back 25

Presentation is the position of the fetus.

Front 26

What is the most common presentation of the fetus for a normal delivery

Back 26

Vertex position (head down)

Front 27

What does the term dystocia mean?

Back 27

Dystocia is a prolonged, difficult labor and delivery

Front 28

What are some possible causes of dystocia?

Back 28

uterine dysfunction (abnormal contractions of the uterus)
abnormal fetal presentation
excessive fetal size
hydrocephalus
abnormality of the birth canal

Front 29

What is the normal heart rate of a fetus in early gestation and when near term?

Back 29

early gestation 140/min
near term 120/min

Front 30

what are the three methods of fetal heart rate monitoring?

Back 30

1. abdominal transducer
2. abdominal electrode
3. fetal scalp electrode

Front 31

What are two methods of uterine contraction monitoring?

Back 31

1. tocodynamometer (most common)
2. intrauterine pressure catheter (used in prolonged/difficult labor)

Front 32

What does the term accelerations mean?

Back 32

Accelerations - when FHR > 160/min for less than 2 min.
Sign that fetus is reacting positiviely to a contraction

Front 33

What does the term decelerations mean?

Back 33

Decelerations - when the FHR < 120/min for less than 2 min
May be threatening or harmless depending on timing & characteristics

Front 34

What are the 3 types of Deceleration and which is the most dangerous?

Back 34

Early/Type I decelerations
Late/Type II (Most dangerous)
Type III

Front 35

What are Early/Type I decelerations caused by?

Back 35

Early/Type I decelerations are caused by compression of the fetal head against the cervix. these are benign

Front 36

What are Late/Type II decelerations caused by?

Back 36

Late/Type II decelerations are secondary to uteroplacental insufficiency during contractions, leading to fetal asphyxia

Front 37

What are Type III decelerations caused by?

Back 37

Type II decelerations are secondary to compression of the unbilical cord leading to hypoxia

Front 38

What is a normal pH in the fetus?

Back 38

Normal fetal ph = 7.25
(slightly acidic)
<7.2 signifies severe asphyxia

Front 39

What is the most common abnormal presentation?

Back 39

Breech

Front 40

What are the three subdivisions of a breech presentation?

Back 40

1. Complete - feet, legs & but all present together
2. Incomplete (a.k.a. footing) one or both feet first
3. Frank - butt first

Front 41

Describe these other abnormal presentations: Face, Brow & Shoulder

Back 41

Face (aka stargazer) - face first (great risk of spinal injury)
Brow - forehead first (also spinal injury risk)
Shoulder - shoulder first ( baby lying side to side in birth canal)

Front 42

What is the substance within the umbilical cord known as?

Back 42

Whartons Jelly

Front 43

What does the term prolapse of the cord mean?

Back 43

prolapse of the cord - is when the cord passes through the cervix into the birth canal ahead of the fetus and or a body part

Front 44

What does occult prolapse mean

Back 44

Occult prolapse is when the cord is compressed inside the uterus

Front 45

How is placental previa diagnosed?

Back 45

by ultrasound

Front 46

What does the term abruptio placentae mean?

Back 46

Abruptio placentae is a term used to describe the placentae detaching early from the uterine wall

Front 47

What frequently causes premature labor?

Back 47

abruptio placentae

Front 48

What is the most common cause of abruption? (abruptio placentae)

Back 48

maternal hypertension (including preclampsia)

Front 49

What is preclampsia?

Back 49

Preclampsia is the development of hypertension during pregnancy along with proteinuria and/or edema

Front 50

What classification of abruptio placentae is the mother actively hemorrhaging?

Back 50

Grade 3 - maternal shock & persistant abdominal pain present. Fetus is dead.

Front 51

What is transient tachypnea of the newborn? (TTN)

Back 51

When the baby retains somes of their fetal lung fluid; may resolve on its own or MV may be required

Front 52

What stimulates a newborns first breath?

Back 52

Increased PaCO2, decreased PaO2 and pH stimulate the chemoreceptors when stimulate a gasp

Front 53

How is the first recoil of the newborns chest acheived?

Back 53

As thorax passes through birth canal it is compressed. when the baby is born the natural recoil of thorax creates a neg. pressure in thoracic cavity causing air to enter the lungs

Front 54

What action begins the conversion of the newborns circulatory system?

Back 54

The cutting of the umbilical cord alters circulatory pressures and signals closure of fetal shunts

Front 55

What 2 anatomical differences present in the infant increase their risk for upper airway obstruction?

Back 55

infant tongue is proportionately larger than adult.
large amt. of lymphoid tissue in the pharynx area

Front 56

What is the narrowest point of the tracheobronchial tree of an infant?

Back 56

The cricoid cartilage

Front 57

How are increases in min. ventilation accomplished by the infant?

Back 57

Minute ventilation is increased by the infant by increasing the RR not the tidal volume

Front 58

Why is a babies need for oxygen greater than that of an adult?

Back 58

Infants have a higher metabolic rate then adults, this also accounts for an unpredictability in medication dosing

Front 59

What are the three Neonatal assessment scoring systems?

Back 59

1. Dubowitz (and Ballard)
2. APGAR
3. Silverman

Front 60

What does the Dubowitz (and Ballard) scoring system assess?

Back 60

Dubowitz (and Ballard) Scoring: used for determining gestational age

Front 61

What is the APGAR scoring system used to assess?

Back 61

APGAR scoring evaluates the infants general condition at birth

Front 62

What does the Silverman scoring system assess?

Back 62

Silverman scoring system assesses the severity of respiratory distress

Front 63

What are the appropriate actions according to an APGAR Score of 7-10?

Back 63

7-10: normal, observation, suction UA w/bulb syringe, dry infant & place under warmer

Front 64

What are the appropriate actions according to an APGAR Score of 4 -6?

Back 64

4-6: indicates moderate asphyxia; requires stimulation & O2 administration

Front 65

What are the appropriate actions according to an APGAR Score of 0-3?

Back 65

0-3: indicates severe asphyxia; requires inmediate resucitation w/ventilatory assistance

Front 66

What score associated with the 5 min APGAR assessment is associated with major complications and requires TX ib tge ICU?

Back 66

a 5 minute APGASR score of <6 requires treatment in an IC nursery

Front 67

What does acrocyanosis mean?

Back 67

acrocyanosis - discoloration of hands and feet; normal after birth

Front 68

What does the observation of cyanosis indicate?

Back 68

O2 therapy must be administerd immediately.
Cyanosis seen in the mucous membranes or lips

Front 69

What neumonic can be used to remember APGAR?

Back 69

A: appearance (color)
P: pulse (HR)
G: grimace (reflex ability)
A: activity (muscle tone)
R: respiration (respiratory effort)

Front 70

Silverman scoring characteristics

Back 70

determines severity of Respiratory distress; 5 areas are assessed each worth 0-2 pts. Lowest score is minimal distress

Front 71

What are the Silverman assessment areas?

Back 71

intercostal retractions
xiphoid retractions
chest lag or paradoxical breathing
nasal flaring
grunting

Front 72

What is the importance of determining the neonate's actual gestational age?

Back 72

to allow care that focuses on special problems of premature gestation;

Front 73

Which of the Scoring assesments is considered the most accurate for gestational age?

Back 73

The Dubowitz is most accurate within 2 weeks of gestational age

Front 74

What is the etiology of RDS (respiratory distress syndrome)

Back 74

RDS has an underlying cause of a deficiency in surfactant production

Front 75

What does the term Gravida mean?

Back 75

Gravida - number of pregnancies

Front 76

What are the normal ranges of vital signs in Newborns

Back 76

HR - 100-180
RR - 30-60
Temp - 96-99.5
BP - systolic 60-90
diastolic 20-60
Average - 75/40

Front 77

When is apnea in a newborn considered to be abnormal/pathological?

Back 77

Apnea lasting 14 seconds or more is considered to be abnormal/pathological

Front 78

How is respiratory distress assessed in an infant?

Back 78

retractions
nostril flaring
see-sawing (belly goes out on I)
grunting (profound sign of distress)

Front 79

How is fetal Hb different then adult Hb?

Back 79

Has a greater affinity for O2. has a natural left shift of the OHDC

Front 80

How do the upper airways of infants differ from adults?

Back 80

very short necks
very straight eustacian tubes
curvature into the R. main bronchus is not as profound
aspiration can be easily distributed throughout both lunds

Front 81

What is diaphragmatic hernia?

Back 81

diaphragmatic hernia - when 1 or more of the normal 4 leafs of the diaphragm doesn't develop. lets abdominal contents into thoracic area

Front 82

What are the benefits of the first breath?

Back 82

helps expel fetal lung fluid
helps to expand the lungs/alveoli
establishes the FRC

Front 83

What is oligohydraminos?

Back 83

Oligohydraminos - low level of amniotic fluid - causes hypoplasia

Front 84

What is the normal amount of amniotic fluid

Back 84

1 liter

Front 85

Where is surfactant produced and what is it's primary role?

Back 85

Type II pneumocytes produce surfactant. Main role is to lower surface tension

Front 86

Low surfactant causes:

Back 86

alveoli to be harder to inflate
harder to keep alveoli inflated
once they are inflated

Front 87

What are the functions of amniotic fluid?

Back 87

cushion
temperature regulator
vehicle for fluid exchange

Front 88

At what age are the fetal shunts normally closed?

Back 88

6 months

Front 89

What vein or artery carries the freshly oxygenated blood from the placenta to the fetus?

Back 89

umbilical vein

Front 90

Where do the two umbilical arteries branch from?

Back 90

The internal iliac arteries

Front 91

When is the heart structurally functional?

Back 91

Heart is structurally functional at 4 weeks