Paediatric anatomy

Question 1

When are the lungs compatible with life?

Answer 1

23/24 weeks

Question 2

4 stages of lung development?

Answer 2

• Embryonic phase (weeks 3-5)
• Pseudoglandular phase (weeks 6-16)
• Canalicular phase (weeks 17-24)
• Alveolar sac phase (weeks 24-birth)

Question 3

What is surfactant and why is it useful?

Answer 3

Fluid that stays within alveoli and helps to create surface tension in alveoli:

→ aids with elastic recoil - surface tension in surfactant helps to bring lungs down to aid with passive expiration
→ creates fluid layer - aids with gas transport across alveoli and gas
→ becomes useful at 30 weeks
→ premature baby will need artificial surfactant to participate in gas exchange

Question 4

What is at risk of being aspirated at birth?

Answer 4

Meconium ileus

Question 5

Anatomy of paediatric chest?

Answer 5

→ Lung structure fully mature at birth but alveoli immature - increase in no and size until age 8
→ Obligatory nose breathers
→ Diameter of trachea narrow
→ More cartilage and connective tissue in bronchial walls+ less muscle than adults
→ High compliance of chest wall with soft thoracic cage
→ Ribs almost horizontal
→ Different muscle fibres in the diaphragm

Question 6

Differences in paediatric anatomy and physiology?

Answer 6

• immature cilia (decreased clearance - shorter/don’t grip onto sputum as well)
• short and squat trachea - greater potential for aspiration
• heart, thymus and thoracic organs relatively large in comparison
• increased resistance and compression on lungs
• foetal arterials more muscular than adults (increased vascular resistance)
• minimal alveoli at birth - 150m, increases to 300-40m by age 4
• full mature alveolar system not reached until age 8

Question 7

Signs of respiratory distress in infants?

Answer 7

→ RR - 60
→ Nasal flare
→ Intercostal, sternal subcostal recession
→ Grunting
→ Head bobbing
→ “turning blue”
→ parents know

Question 8

How may paediatric patients be positioned?

Answer 8

• have a “floppy” and easily compressed ribcage due to cartilaginous ribs up until age of 18-24 months
• also greater risk of alveolar collapse due to lack of basal expansion and lack of cartilaginous support around distal airways
• therefore, advised not to use “good lung down” in paediatrics until 2 years of age
• better position is slightly head up tilt or alternative half side lying

Question 9

Considerations for treatment?

Answer 9

• better effectiveness of manual techniques (percussion) due to cartilaginous “floppy ribcage”
• one-handed techniques for children under 7-8
• risk of rapid desaturation/bradycardia during treatment

Question 10

Wider paediatric considerations?

Answer 10

• the importance of play/activities - need to make treatment “fun”
• length of treatment/amount of handling
• legal issues and media representation
• assessing the child as a whole
• individualised intervention programmes