Pulmonology

Question 1

Total respiratory system resistance

Answer 1

R= change in pressure (cm H2O)/ change in flow (L/sec)

Total value is 40-55 cm H2O/L/sec

Question 2

Greatest resistance in airway-location?

Answer 2

50% of airway resistance is due to nasal resistance

Distal airways contribute very little

Question 3

What are the 3 factors that co2 elimination depend on?

Answer 3

1. Alveolar minute ventilation
2. Diffusion across capillary membrane
3. Matching of alveolar ventilation with pulmonary blood flow.

Question 4

Which factors increase MAP?

Answer 4

Increase PEEP
Increase PEP
Increase rate
Increase flow
Increase itime
Decrease e-time

Question 5

CCAM facts

Answer 5

Connected to tracheobronchial tree
Has 5 types, type 1 and 2 are most common
Most regress in utero
Supplied by pulmonary circulation

Question 6

Which surfactant protein deficiency is not associated with clinical disease?

Answer 6

Surfactant protein D

Question 7

Largest component of surfactant?

Answer 7

Disaturated phosphatidylcholine

Question 8

Transport of which ion is responsible for fetal lung fluid formation

Answer 8

Chloride = Creation of Critical lung fluid

Question 9

Which ion is responsible for fetal lung fluid clearance?

Answer 9

Sodium

Question 10

Chest wall movements with unilateral diaphragmatic paralysis?

Answer 10

Affected side has fewer movements compared to unaffected

R sided paralysis more common

Question 11

Embryonic stage of lung development:

1. Weeks of gestation
2. What forms?
3. Defects during this stage

Answer 11

1. 0 - 7 weeks
2. Trachea and bronchi
3. Tracheal stenosis, TE fistula, laryngeal cleft

Question 12

Pseudoglandular stage of lung development:

1. Weeks of gestation
2. What forms?
3. Defects during this stage

Answer 12

1. 7 - 17 weeks
2. Non respiratory bronchioles.
3. Branching abnormalities, CDH, CCAM, bronchogenic cysts, congenital lobar emphysema

Question 13

Canalicular stage of lung development:

1. Weeks of gestation
2. What forms?
3. Defects during this stage

Answer 13

1. 17 - 27 weeks
2. Respiratory bronchioles. Type 2 pneumocytes differentiate into type 1
3. Pulmonary hypoplasia

Question 14

Saccular stage of lung development:

1. Weeks of gestation
2. What forms?
3. Defects during this stage

Answer 14

1. 27 - 36 weeks
2. Alveolar ducts and sacs
3. Pulmonary hypoplasia

Question 15

Alveolar stage of lung development:

1. Weeks of gestation
2. What forms?

Answer 15

1. After 36 weeks

2. Alveoli

Question 16

Lecithin vs sphingomyelin: which reflects lung maturity?

Answer 16

Lecithin. Increases with increasing gestation.

Sphingomyelin decreases with inc gestation

Question 17

Surfactant protein associated with most severe lung disease?

Answer 17

Surfactant protein B

Question 18

Which chromosomes are each surfactant protein on?

Answer 18

A and D on chromosome 10
B on 2
C on 8

Question 19

Most abundant surfactant protein?

Answer 19

SP-A

Question 20

Most common known genetic cause of surfactant deficiency?

Answer 20

ABCA3 deficiency
Autosomal recessive
Lack of DPPC, PG and lamellar bodies

Question 21

Which factors determine the oxygen sat?

Answer 21

paO2 and O2 dissociation curve factors

Question 22

What is paO2 and what determines it?

Answer 22

Oxygen dissolved in the plasma. Determined by alveolar pO2 and the alveolar-capillary interface

Question 23

What does the oxygen sat reflect?

Answer 23

Percentage of all available heme binding sites that are bound to oxygen

Question 24

Which factors does oxygen content depend on?

Answer 24

Hb concentration, oxygen saturation and dissolved O2 (lower effect because paO2 x 0.003). Main factors are Hb conc and O2 sat in a linear relationship

Question 25

Best waveform to detect air leak?

Answer 25

Volume waveform

Question 26

What is the belly dancer's sign? When is it seen?

Answer 26

Shift of umbilicus towards one side during inspiration. Seen during unilateral diaphragmatic paralysis, shift is towards affected side

Question 27

Most common type of stridor?

Answer 27

Biphasic stridor due to laryngeal obstruction

Question 28

Most common congenital laryngeal anomaly?

Answer 28

Laryngomalacia

Question 29

Most common vascular ring?

Answer 29

Double aortic arch due to prevailing right and left 4th branchial arches

Question 30

Diagnostic test for vascular rings?

Answer 30

Barium swallow

Question 31

What embryological defect leads to CDH?

Answer 31

Failure of closure of pleuroperitoneal canal at 8 weeks gestation

Question 32

During what stage does surfactant production begin?

Answer 32

Canalicular

Question 33

What is new BPD?

Answer 33

Pulmonary changes consistent with altered lung development 1. Arrest of alveolarization 2. Increased alveolar development 3. Fewer alveoli 3. Disruption of collagen network around the saccules 4. Localization of elastin that is absent from sites of future septation 5. Less airway reactivity compared to old BPD 6. Less pHTN 7. Minimal fibrosis Results from impaired acinar development with alveolar simplification New BPD interferes with lung development, old BPD is caused by direct injury to the lung

Question 34

Effect of antenatal and postnatal steroids on the lungs

Answer 34

Antenatal: matures the fetal lung, by decreasing mesenchymal tissue and increasing airspace volume. Results in arrest in alveolar septation Postnatal: arrest in alveolar septation and microvascular development

Question 35

Which inhibitory neurotransmitters contribute to apnea of prematurity?

Answer 35

GABA and adenosine

Question 36

Most accurate ETT depth estimation is based on?

Answer 36

The most accurate methods currently available to estimate depth for initial endotracheal intubation are based on “nasal-tragus distance + 1 cm,” or gestational age.

Question 37

Core feature separating new from old BPD?

Answer 37

Alveolar simplification is the core pathologic feature that separates classic BPD from the new BPD.

Question 38

Why do premies need caffeine boluses as they get older?

Answer 38

Increased metabolism because the t1/2 decreased due to an increase in CYP1A2 activity