Developmental aspect of lung disease

Question 1

Whats the gestational age for embryonic, Pseudoglandular, canalicular, saccular and alveolar?

Answer 1

E: 3-8 weeks
P: 5-17 weeks
C: 16-26 weeks
S: 24-38 weeks
A: 36 weeks

Question 2

Describe the morphogenesis in embryonic

Answer 2

Lungs originate from oespophagus

Respiratory diverticulum – trachea

In stage C, the lobes can sometimes be seen developing

Question 3

Describe the morphogenesis in pseudoglandular

Answer 3

COnducting segments start to develop alongside the cilia and mucous

Question 4

Describe the morphogenesis in canalicular

Answer 4

Early gas exchange begins to start

Development of small sacs that develop into alveoli

Surfactant organs began to develop too

Question 5

Describe the morphogenesis in saccular

Answer 5

Precursors for alveoli

Development of type 1 and type 2

Question 6

Describe the morphogenesis in alveolar

Answer 6

Once filled with air will change shape and geometry and continue to grow for the next 2-3 years

Question 7

What is postnatal lung growth?

Answer 7

Alveolar septation continues
100-150 million at birth to 200-600 million at 3-8 years
Increased alveolar dimensions thereafter
MRI suggests new alveolar development up to late childhood

Question 8

At which week can babies survive with ventilation?

Answer 8

Week 24

Question 9

Name 3 common congenital upper abnormalities

Answer 9

Tracheal agenesis and stendosis
tracheomalacia
tracheo-oesophageal fistula

Question 10

Name 3 common congenital lower abnormalities

Answer 10

Lung agenesis/pulmonary hypoplasia
bronchogenic cyst
CPAM
congenital diaphragmatic hernia

Question 11

When does ultrasound happen for mum and baby?

Answer 11

At around 12 weeks during antenatal screening

Question 12

Presenting features in newborn for lung disease

Answer 12

Newborn
Tachypnoea
Respiratory distress
Feeding issues

Question 13

Presenting features in Childhood for lung disease

Answer 13

Stridor/wheeze
Recurrent pneumonia
Cough
Feeding issues

Question 14

Presenting features in asymptomatic for lung disease

Answer 14

Incidental findings

Question 15

What is tracheal agenesis?

Answer 15

Very rare an presents at birth with acute respiratory distress and inability to intubate

Question 16

What is tracheal stenosis?

Answer 16

Very rare
Complete tracheal cartilage rings, may be generalized or segmental
Present at birth or within first year

Funnel shape near the end of the branching into two bronchi

Question 17

What is tracheomalacia?

Answer 17

Dynamic abnormal collapse of tracheal walls
and leads to floppiness.

Can be caused by external compression

Question 18

What is presentation of tracheomalacia?

Answer 18

Presentation:
Barking cough
Recurrent “croup”
Breathless on exertion
Stridor/wheeze

Question 19

What is tracheo-oesphageal fistula?

Answer 19

Abnormal connection between trachea and oesphagus

Association with genetic conditions

Question 20

What is presentation and treatment of tracheo-oesphageal fistula?

Answer 20

May be diagnosed antenatally or postnatally

Presentation: 
Choking
Colour change
Cough with feeding
Unable to pass NG

Treatment with surgical repair

Complications include tracheomalacia, strictures, leak and reflux

Question 21

What is congenital pulmonary airway malformation?

Answer 21

Abnormal non-functioning lung tissue
80% detected antenatally
Occur sporadically

May resolve spontaneously in utero
Conservative management if asymptomatic
Surgical intervention may be required
Possible risk of malignant change

Question 22

When is diaphragm developed and closure occurs?

Answer 22

Around 7 weeks from multiple tissues

Closure by 18weeks

Question 23

Describe congenital diaphragmatic hernia and its managment

Answer 23

Affects 1 in 2500 births
Different types, most common Bochdalek (90%)
Usually left side > right side

Most diagnosed antenatally
Some cases diagnosis late

Management surgical repair

Prognosis depends on degree of lung hypoplasia

Question 24

What are the changes in lungs after birth?

Answer 24

Significant changes occur at birth after first breath

Lungs inflate and fluid in lungs is absorbed

Question 25

What is transpient trachypnoea?

Answer 25

Transient tachypnoea of newborn
Associated with C-section
Improves within 1-2 days

Question 26

What is the surfactant system made up from?

Answer 26

Surfactant
Complex mix of phospholipids and lipophilic proteins
Reduces surface tension at alveoli and promote gas exchange

Type II pneumocytes
Produce and secrete surfactant
Differentiate 24-34 weeks

Question 27

When does Respiratory distress sydnrome occur? RDS

Answer 27

Hyaline membrane disease

Occurs with preterm infants with surfactant deficiency

Question 28

Treatment for RDS?

Answer 28

Antenatal steroids
Surfactant replacement
Appropriate ventilation and nutrition

Question 29

What is chronic lung disease and treatment?

Answer 29

Ongoing oxygen requirement at term and multifactorial causes and associated with increased childhood respiratory morbidity.
May cause COPD in future

Question 30

What does remodelling in lungs involve?

Answer 30

Its caused by the interference of intercellular signalling.

Its the alteration of airway structure following external influence:
Environmental exposures
Chronic diseases of childhood
Infection

Question 31

Describe remodelling in asthma

Answer 31

Chronic inflammation
Increased bronchial responsiveness
Increase mucus secretion
Airway oedema
Airway narrowing

Question 32

Describe remodelling in chronic lung disease

Answer 32

Chronic inflammation
Interference inter-cellular signalling
Treatment toxicity

Question 33

What does smoking do on rate of decline in FEV?

Answer 33

Smoking decreases the FEV as age increases