Lecture 10 -airways In Children Flashcards
Why is ling development important?
For aerobic cellular respiration
What are the goals of lung development?
Large Surface area, vascular system, prevent alveolar collapse and host defence
What happens to the lungs 4-7 weeks in the embryonic stage?
Right and left lung bud formation, branching morphogenesis and visceral and parietal pleura formation
What happens for lung development 5-17 weeks in the psuedoglandular stage?
Smooth muscle and cartilage formation, development of mucus glands and blood vessel development
What % of births are pre term?
7%
What is a key problem for babies born preterm?
They wont have the surfactant present in the type 2 alveolar cells
What is a significant risk in pre term babies?
Lung disease - the highest risk is at 24-28 weeks, this is just as the airways juxtapose with blood vessels
What diseases are you more likely to have if you were born early?
Asthma and COPD
What is used for cystic fibrosis?
Modulators - CFTR channel proteins modulators
What is the most superior CF drug?
Kaftrio
What happens 16-26 weeks in lung development canalicular stage?
Increase in airway size, widening of epithelial cells, early surfactant product by type 2 cells
What is moderate to late preterm?
Around 32 to 37 weeks
What can happen for lung development in 26-36 weeks in the saccular stage?
Collagen and elastic fibre deposition, end of branching morphogenesis
What is extreme preterm?
Less than 28 weeks
What is very preterm?
28 to 32 weeks
What are the effects of prematurity on the lungs?
Risk of chronic lung disease, the highest risk is 24-28 weeks gestation - as the airways juxtapose with blood vessels
What is angiogenesis in chronic lung disease?
Administers surfactant to preterm babies, helps with biochemical and functional issues
What is the control of breathing like in children?
Immature - decrease respiratory rate causing apnoea
What is the pattern of breathing in children?
It can be irregular and periodic
What are the airway sizes like in children?
Small airways so there is a higher resistance to airflow
What is the airway compliance and respiratory muscles like in children?
Airway compliance - high and respiratory muscles are inefficient (diaphragms do most of the work)
What are the respiratory rates like in children?
Raised respiratory rate and a lower tidal volume
What is the total lung capacity and functional residual capacity like in children?
Low - children are more vulnerable to lower rapid drops in oxygen
How do you measure lung physiology in children?
Pulse oximetry
What does saturation =?
Percentage of available Hb saturated with O2
What does Hb absorb?
Different wavelengths depending on degree of oxygenation
How is CO2 measured in children?
A small adhesive patch is applied to the skin, it warms the skin to allow CO2 to diffuse
What does spirometry measure?
VC, FEV1,FVC
What is CF?
It is an autosomal recessive disease, defects in the CFTR gene
What happens in the CF airways?
Abnormal mucociliary clearance, ongoing infection and progressive inflammation
How is FEV1 a key parameter of lung function testing?
It correlates best with airway all thickness and mucus plugging which are features of large airway obstruction and occur later in disease
What are the limitations of FEV1?
Doesn’t pick up the damage to the smaller airways that occurs early in CF
How early can lung damage start?
As early as 3 months - changes on lung CTs in 1st year of life
What is a useful tool for very young children?
Lung clearance index
What is an advantage in lung clearance index (LCI)?
Can be used in young children
What is an example of a CF potentiator?
Ivacaftor
What is an example of CF corrector?
Lumacaftor - used to correct CFTR protein production
