Developmental aspects of lung disease

Question 1

Stages of lung morphogenesis + Gestational age

Answer 1

Embryonic ( 3-8wks)

Pseudogladular ( 5-17wks)

Canalicular (16-26wks)

Saccular (24-38wks)

Alveolar (36wks -2/3yrs)

Question 2

Postnatal lung growth

Answer 2

Alveolar septation continues + increased alveolar dimensions thereafter

Question 3

State the common congenita abnormalities in Upper + Lower

Answer 3

Upper (Tracheo-brachial)

• tracheal agenesis + stenosis
• tracheomalacia
• tracheo-oesphhageal fistula

Lower ( Broncho-pulmonary)

• Lung agenesis/pulmonary hypoplasia
• Bronchogenic cyst
• CPAM
• Congenital diapgragmatic hernia

Question 4

State the presenting features in : antenatal scanning, newborn, childhood, asympomatic

Answer 4

Antenatal scanning:
-ultrasound

Newborn:

• tachypnoea
• respiratory distress
• feeding issues

Childhood

• stridor/wheeze
• recurrent pneumonia
• cough
• feeding issues

Asymptomatic
-incidental finding

Question 5

Presentation of tracheal agenesis

Answer 5

• presents at birth with acute respiratory distress and inabiity to intubate

Question 6

Tracheal stenosis

Answer 6

• Complete tracheal rings, may generalised or segmental

- present at birth/within first

Question 7

Tracheomalacia

Answer 7

-Dynamic abnormal collapse of tracheal

Question 8

Presentation of tracheomalacia

Answer 8

• Barking cough
• recurrent ‘croup’
• breathless on exertion
• stridor/wheeze

Question 9

Management of tracheomalacia

Answer 9

physiotherapy + antiobiotics(unwell)

Question 10

Causes of tracheomalacia

Answer 10

• associated with genetic conditions

- may be caused by external compression ( eg vessels, tumour)

Question 11

What is tracheo-oeasophageal fistula?

Answer 11

• Abnormal connection between trachea and oesophagus

- association with genetic conditions

Question 12

Diagnosis of tracheo-oesophageal fistula

Answer 12

-antenatally or postnatally

Question 13

Presentation of tracheo-oesophageal fistula

Answer 13

• choking
• color change
• cough with feeding
• unable to pass NG

Question 14

Treatment and complications of tracheo-oesophageal fistula

Answer 14

• surgical repair

- tracheomalacia, strictures, leak + refliux

Question 15

Congenital pulmonary airway malformation (CPAM)

Answer 15

• abnormal non-functioning lung tissue
• sporadically

-risk of malignant change

Question 16

CPAM treatment

Answer 16

• can be resolved spontaneously in utero

- surgical intervention maybe

Question 17

Diaphragm development

Answer 17

• develops from multiple tissues around 7wks
• Innervated by phrenic nerve
• Closure by 18wks

Question 18

Congenital diapgragmatic hernia

Answer 18

• mainly bochdalek + usually LHS

- prognosis depends on degree of lung hypoplasia

Question 19

Congenital diapgramatic hernia diagnosis + treatment

Answer 19

• antenatally or late

- Surgical repair

Question 20

Changes in lungs after birth

Answer 20

• occurs after first breath
• lungs inflate and fluid in lungs is absorbed

-Transient tachypnoea of newborn (associated with C section)

Question 21

Type 2 pneumocutes differentiates when?

Answer 21

24-34 wks

Question 22

Treatment of IRDS

Answer 22

• antenatal steroids
• surfactant replacement
• appopriate ventilation + nutrition

Question 23

Neonatal lung disease ( bronchopulmonary dysplasia)

Answer 23

-chronic LD associated with prematuririty where ongoing oxygen requirement at term
-multifactorial causes
-associated with increased childhood respiratory morbidity
-

Question 24

Relationship between fetal/paediatric + adult lung disease

Answer 24

ANTENATAL

• Nicotine exposure
• Infection
• Maternal nutrition
• Maternal micronutrients/vitamins
• Low birth weight/prematurity
• Antenatal steroids

POSTNATAL

• Barker hypothesis
• Infection
• Growth
• Tobacco exposure
• Environmental pollution
• Micronutrients/vitamins

Question 25

Describe remodelling

Answer 25

-alteration of airway structure following external influence:

• Environmental exposures
• Chronic diseases of childhood
• Infection
• Causes interference of inter-ceular signaling

Question 26

Remodelling ( asthma )

Answer 26

Chronic inflammation

• increased bronchial responsiveness
• Increase mucous secretion
• airway oedema
• airway narrowing

Question 27

Remodelling ( chronic lung disease)

Answer 27

• chronic inflammation
• interference inter-cellular signalling
• treatment toxicity