Respiratory Distress Syndrome

Question 1

Common causes of respiratory distress in newborns

Answer 1

RDS
Airleak (pneumothorax)
Meconium Aspiration Syndrome
Neonatal Pneumonia
Pulmonary Hemorrhage

Question 2

Acrocyanosis

Answer 2

Cyanosis of the periphery (blue nails)

Question 3

Cause of RDs

Answer 3

Deficiency of surfactant in premature babies.

Leads to poorly compliant lungs, atelectasis, increased work to breathe, and hypoxia

Question 4

Likelihood of RDS at 29 week gestation? Full Term?

Answer 4

60%

near 0%

Question 5

Risk factors for RDS?

Answer 5

Fetal hyperinsulinism
Fetal asphyxia
Multiple gestations
Male>Female
Caucasian>Black

Question 6

Five stages of lung development

Answer 6

Embryonic
Pseudoglandular
Canacular
\_\_\_- (who fucking knows)
Alveolar

Question 7

Embryonic period lasts from

What forms

Answer 7

0-6 weeks, bronchi develop

Question 8

Pseudoglandular period happens from

What forms

Answer 8

7-16 weeks

COnducting airways, Branching pattern

Question 9

Canalicular period happens from…

what forms?

Answer 9

17-25 weeks
Acini
Resp bronchiole, alveolar duct+Sac
Type II alveolar cells (20 weeks)

Question 10

Subsaccular period happens from…

what forms?

Answer 10

25-35 weeks
Primitive alveoli
Decrese inerstitial thickness, eparate terminal air units
Type I and II differentiate
Lamellar bodies develop

Question 11

Alveolar period happens from…

what forms?

Answer 11

36 w-3yo

• Invagination of terminal saccules and formation of secondary perfusion
• Collagen synthesis
• Further interstitial thinning
• Appearance of a single capillary network.

Question 12

Anything born before _____ is a non-viable birth

Answer 12

20 weeks

You’ve got no lung to work with

Question 13

What is surfactant

Answer 13

A lipoprotein – Saturated phosphatidylcholine

Question 14

Surfactant is made where?

Answer 14

Smooth ER of Type II Alveolar Cells

Question 15

Surfactant in stored intracellularly where?

Answer 15

Lamellar Bodies

Question 16

Surfactant is converted to…

Answer 16

Tubular myelin

Question 17

Who has a regulatory role in surfactant production?

Answer 17

Steroids and thyroid hormones

Question 18

_____ stimulate the Surfactant secretion at birth

Answer 18

Catecholamine surge and Lung distention

Question 19

What does SP-A do?

Answer 19

Forms an integral part of tubular myein
Inhibits secretion, but stimulates reutilization
Role in determinine surfactant pool size

Question 20

What does SP-D do?

Answer 20

Innate host defense from viral infections
Surfactant lipid homeostasis
Protect from oxidant damage

Question 21

What does SP-B do?

Answer 21

Surface tension reduction

Formation of Lamellar bodies + Tubular myelin

Question 22

What does SP-C do?

Answer 22

Surface absorption of phospholipids

Question 23

Agents that inhibit surfactant fxn

Answer 23

AMNIOTIC FLUID + MECONIUM

Albumin, Bilirubin, Cholesterol, Elastin, Blood products

Question 24

Law of Laplace =

Answer 24

Pressure to keep it open = 2Tension / radius

Question 25

Pressure required to keep an alveoli open is ____ to surface tension and _____ to alveolar radius

Answer 25

directly proportional | inversely proportional

Question 26

Relationship between Surfactant and law of laplace

Answer 26

Surhactant lowers surface tension by displacing water molecules, helps alveoli not close on expiration

Question 27

RDS pathogenesis

Answer 27

Deficient surfactant at air-fluid interfact caused by secretion problem. Causes atelectasis. Other alveoli distend and epithelial damage occurs.

Question 28

Effects of no surfactant on alveoli fxn

Answer 28

``` Poor stability R to L shunting of blood Reduced effective pulmonary BF Edema Decreased Compliance ```

Question 29

How to diagnose RDS Clinically?

Answer 29

Premature infants Tachypnea, Central Cyanosis, Labored breathing Retractions, Flaring, Grunting Auscultation may reveal fine rales

Question 30

Why do adults inspire by chest out while RDS babies go in

Answer 30

In adults, compliance + negative pressure will do it Babies are less compliant lungs and ribs are still too soft. Negative pressure causes the rib cage to collapse instead of making the lungs expand

Question 31

How to diagnose RDS in Lab studies?

Answer 31

Hypoxia, Hypercarbia, Acidosis

Question 32

How to diagnose RDS -- Radiographic?

Answer 32

Granular densities within hours | Ground Glass appearance

Question 33

How to prevent RDS?

Answer 33

Reduce preterm births Predict at risk pregnancies, treat with antenatal glucocorticoid hormones Prophylactic/Early treatment of high risk infants with exogenous surfactant in delivery room

Question 34

RDS Treatment

Answer 34

Resuscitation by skilled team Intratracheal administration of exogenous surfactant Neonatal care (temp, infection control, nutrition, fluids) Assisted ventilation

Question 35

What does grunting do for baby?

Answer 35

Adds resistance via closed glottis More pressure Keeps lung/alveoli open

Question 36

Potential outcomes of RDS

Answer 36

``` Recovery Barotrauma/Volutrauma Chronic lung disease Intraventricular Hemorrhage, Retinopathy of Prematurity Death ```

Question 37

PDA closed with...

Answer 37

Endomethacin