Why infants wheeze Flashcards
Physiologically, why does a wheeze occur? [1]
Explain when this occurs and why [2]
Air rapidly flows through an obstructed airway - creates a high pitched noise
Wheezing is more common during expiration because increased intrathoracic pressure during this phase narrows the airways and airways narrow as lung volume decreases.
Wheezing during expiration alone indicates milder obstruction than wheezing during both inspiration and expiration, which suggests more severe airway narrowing.
When does wheeze occur: Inspiratory or Expiratory?
When does croup occur: : Inspiratory or Expiratory?
When does wheeze occur: Expiratory
When does croup occur: : Inspiratory
Where does wheeze and croup occur in resp. tract? [2]
Wheeze: intrathoracic region / lower resp tract
Croup: extrathoracic region / upper resp tract
Define Bronchiolitis [1]
Bronchiolitis is inflammation of the bronchioles usually caused by an acute viral illness.
What pathogen normally causes pre-school wheeze? [1]
Describe pattern between attacks of pre-school wheeze [1]
What happens to incidence of pre-school wheeze as children age? [2]
- Usually triggered by viral colds
- Syptoms between attacks are few
- 75% of children grow out of wheeze but the remainder develop into asthma
What is difference between pre-school wheeze and pre-school asthma? [2]
Different pathophysiology
Pre-school wheeze: most do not have allergic asthma - more likely to be an exaggerated response to to virus &/ or because airways are not anchored down. No eosinophilic inflammation
Pre-school asthma: eosinophilic inflammation and usual asthma pathway - also caused by other triggers
Risk factors for pre-school wheeze? [5]
smoking in pregnancy
Younger mother
air pollution
Male gender
Premature birth
How does maternal smoking increase liklihood of pre-school wheeze? [2]
Alters airway structure: increased distance between anchoring airways of the lung
Pregnancy effects may occur because phagocytic cells in placenta have fossil fuel derivatives
Why is air pollution particularly pernicious for lungs? [2]
- Stick around in the airways: causes long term effects
- Has jaggered edges
What happens to lung growth if exposed to air pollution? [1]
Lung growth is suppressed by long term exposure to air pollution – a problem for those who are genetically wired to low level lung function
Stepwise treatment of pre-school wheeze? [4]
Step 1: Inhaled SABAs; e.g. salbutamol
Step 2: Inhaled corticosteroids
Step 3: Leukotriene receptor antagonists
Step 4: refer to resp. paediatrician
Future treatments for pre-school wheeze? [2]
Bacterial lysates: given to provide trained innate immunity
Wheeze-scan: detect wheeze more easily
