Why do infants wheeze Flashcards
When is lung fully functional
36-38 weeks
Define wheeze
Musical lung sound
What is a wheeze produced from
Oscillation in narrowed airways
How can wheezes be characterised
Inspiratory or expiraratory
What pressure change happens when you inhale
Negative pressure generated in chest and transferred to small airway
What happens to small airways as you breathe in
Expand/ pulled apart by negative pressure
What happens if small airways narrow
Initially velocity increases, but as narrows further is decreases
Initally pressure decreases but narrows further giving increase
Alternation of these pressure/ velocity changes gives fluttery breaths
What % of children will wheeze before age of 3, and what triggers this most
35
Viral colds
Why is smoking in pregnancy a risk factor for preschool wheeze
Maternal smoking alters airway structure, making it floppier
Apart from smoking what is another risk factor for preschool wheeze
Air pollution
During what age are transient early wheezers most prevalent
0-3
During what age are non-atopic wheezers most prevalent
3-6
During what age is IgE associated wheeze more prevalent
6+
Define transient early wheeze
Wheeze only during first 3 years of life
Born with low lung function and tendency to develop twitchy airway with colds
By what age do transient early wheezers have normal lung function
Age 11
How do non atopic wheezers start wheezing
Symptomatic lower respiratory tract viral infection in early life
What is the difference between non-atopic wheeze and atopic wheeze
There is no inflammation between wheezes in non-atopic
In atopic there is persistent inflammation throughout central and peripheral airways
What 3 histological changes can be seen in atopic asthma
Goblet cell hyperplasia
Thick sub basement membrane
Lymphocyte and eosinophil infiltration
How should preschool wheeze be treated (step 1)
Inhaled, short acting beta 2 agonist
Step 2 of treating preschool wheeze
Inhaled corticosteroids
How does large cystic abnormality present
Early with resp distress or later with infection
What makes up a bronchogenic cyst
Thin walled with ciliated columnar lining
May contain cartilage, smooth muscle
Some have gastro-oesophageal mucosa
Air or fluid filled
What are congenital lobar emphysema
Over distention of lobe
Partial bronchial obstruction
Ball valve effect
