Pulmonary Surfactant Flashcards Preview

Neonatal Pharmacology > Pulmonary Surfactant > Flashcards

Flashcards in Pulmonary Surfactant Deck (44):
1

When was Surfactant discovered?

1920's

2

When was the Significance of Surfactant discovered?

End of the 1950's (surfactant deficiency RDS)

3

What is surfactant?

A surface-active lipoprotein complex formed by Type II Alveolar cells

4

Surfactant lines the _______ and the smallest __________.

Alveoli
Bronchioles

5

Surfactant is produced during the _________ ____ stage of lung development (17-26 wks)

Terminal sac stage

6

Term infants have a storage pool of approximately _____ mg/kg of surfactant.

Pretermers have ___-___ at birth.

100 mg/kg


4-5 mg/kg

7

Alveolar surfactant can be both broken down by __________ and/or reabsorbed into the __________ structures of the Type II cells

Marcrophages

Lamellar

8

Up to ___% surfactant is recycled from the Alveolar space in the NB

90%

9

What 3 factors negatively effect Surfactant quality & production

1. Hyperinsulinism
2. Acidosis
3. MAS (chemical pneumonitis is the probable culprit)

10

What are the 5 functions of surfactant?

1. Increases Pulmonary compliance
2. Reduces surface tension
3. Facilitates recruitment of collapsed airways
4. Protection of the pulmonary epithelium
5. Prevents Atelectasis at the end of expiration

11

What is compliance?

The ability of the lungs & thorax to expand

12

What is water surface tension?

What is lung surface tension?

70 Dynes/cm

25 Dynes/cm
*but at end of expiration, compressed surfactant phospholipid molecules decrease surface tension very low (near 0)

13

Surfactant allows lungs to inflate more _______ and _______ WOB

easily
Decreases

14

Studies of exogenous surfactant administration-->______increase oxygenation and rapid decrease in degree of _________ _____ support required.
Also increased _____ & followed by slower & variable _______ in lung compliance. Also ______in V/Q mismatch.

rapid
mechanical vent

FRC
Increase
Decrease

15

As the _______ increase in size, the ________ becomes distributed.

This also helps all _______ expand at the same rate.

Alveoli
surfactant

Alveoli

16

Keeping airways _____ is very important.

dry

17

By reducing surface tension with Surfactant, the fluid from ________ is not drawn into the alveolar spaces.

What happens without Surfactant?


This keeps the airways ____

capillaries



Surface tension forces draw fluid from the capillaries to the Alveolar spaces

Dry

18

What is the composition of Surfactant?

~40% DPPC (phospholipid-strongest molecule)
~40% other phospholipids (PC)
~5% surfactant-associated proteins (SP-A, B, C, & D)
Cholesterol (neutral lipids)
Traces of other substances

19

What is the strongest surfactant molecule in pulmonary Surfactant mixture?

Dipalmitoylphosphatidylcholine
(DPPC)

20

Name 3 Dz's r/t Surfactant Deficiency

1. RDS
2. Congenital Surfactant Deficiency
3. Pulmonary Alveolar Proteinosis

21

Name 3 other Dz's you may see Surfactant used

1. MAS-Mec inhibits surfactant fxn--> Alveolar collapse. Chemical pneumonitis & acidosis can also have negative effects.

2. Pulmonary Hemorrhage
3. Pneumonia
(not routine use in the above 2--efficacy is not certain)

22

Name the 3 types of Surfactants

1. Synthetic Surfactant
2. Animal-Derived Surfactant
3. Human Amniotic Fluid-Derived Surfactant

23

Which type of Surfactants are used the most?

Animal-Derived Surfactant

24

What is the name of the Synthetic surfactant?

Exosurf--can be w/or without protein components

25

What are the names of the 3 Animal-derived Surfactants?

What are they produced from?

Curosurf---minced pig lung

Infrasurf---calf lung lavage fluid

Survanta---minced cow lung w/additional DPPC, palmitic acid and tripalmitin

26

Has human-derived surfactant undergone clinical trials?

Is it in use in clinical practice?

Yes


No

27

What is the administration technique for Surfactant?

ETT

28

What method of administration is promising in the future?

LMA
**needs to be studied in large, randomized trial
**& LMA's are only avail >1500 gms

29

T/F: Surfactant could be used for Re-treatment w/signs of worsening or persistent RDS.

True

30

A Low/High threashold for peak dosing should be used for babies w/RDS who have perinatal depression or infection.

Low threashold for peak dosing

31

Surfactant is ________ metabolized. There is some _______ _________ of surfactant d/t action of soluble proteins and other factors in the small airways & alveoli.
What may be required?

Quickly
Functional Inactivation


Subsequent doses

32

What does Meta-Analysis of Surfactant studies show?

Decreased risk of pneumothoraces w/multiple-dose Surfactant therapy (practice & pt dependent)

33

What should be monitored when giving Surfactant?

-ETT patency and position
-O2 sats, EKG, B/P (watch for post-dose hyperoxia, hypocarbia, & over-ventilation)
-Blocked airway

34

Use Surfactant in what type of setting?

Highly supervised clinical settings w/immediate availability of clinicians w/experience w/intubation, ventilation management, & general care of preterm infants.

35

When should dosing of Surfactant be slowed or halted?

If dusky, aggitated, HR slows, SpO2's decrease 15% or more, or surfactant backs up into ETT.

36

Name the adverse effects/precautions for Surfactant

1. Reflux of surfactant up the ETT
2. Oxygen desaturation (r/t transient hypoxemia & bradycardia)
3. Pulmonary hemorrhage (2-4%, smallest pts w/untx'd PDA d/t rapid fall PVR-->increased pulmonary blood flow)
4. Post dose hyperoxia, hpocarbia and/or overventilation-->possible pnuemo

37

Are you likely to see adverse effects/precautions in practices used to using Surfactant?

No

38

There is increased risk of death and short-term morbidity r/t what adverse effect of Surfactant?

Pulmonary Hemorrhage

39

Studies show increased liklihood of hemorrhage r/t which surfactant product?

Animal vs. Synthetic

40

What might you need to give after Surfactant is given?

Increased FiO2 or vent settings (i.e. MAP)

41

Has the rate of IVH fallen since the use of Surfactant?

No consistent effect on IVH has been observed.

42

Animal-derived surfactant has specific proteins that aid in __________ _______ and resist _________ ____________

surfactant absorption
Surfactant inactivation

43

Animal-derived surfactants have more rapid ______ of action

onset

44

Animal-derived surfactants should be favored in clinical situations because of greater ________ than synthetic surfactants

benefits