29. Why do Infants Wheeze? Flashcards
What condition does this CT scan of the right lung show? (Normal on the L, pathology on the R).
Bronchiectasis: enlarged airway. Arrow = cignet ring sign.
Describe a wheeze and what makes it.
Why does wheezing tend to expiratory?
A musical lung sound from oscillations in narrowed airways. Frequency depends on degree of narrwowing, elastcity of airway wall and local airflow. Can be insipiratory/expiratory and high/low pitched. Usually starts EXPIRATORY.
Due to intrathoracic obstruction: Inspire and -ve pressure in tissue structures transmitted to intrathoracic airways, so -ve pressure relative to mouth pulls air in. Breathe in = tendency for smaller airways feeling -ve pressure to open up naturally. They get a bit smaller on expiration, so if wheeze related to relative narrowing of airways then will hear it on expiration first.
Describe the pressure and airway changes that result in stridor.
What is the typical cause of preschool wheeze?
What are some risk factors for preschool wheeze?
Breathe in: -ve pressure and airways open up BUT they tend to close because -ve pressure transmitted so larger airways tend to get narrower on inspiration and wider on expiration.
Colds. ‘Wheeze attacks’ usually short, minimal symptoms.
Smoking in pregnancy (alters airway structure), air pollution (supresses lung function growth in later childhood)
What are the 3 different wheeze phenotypes?
1. Transient early wheezers (0-3yrs, born with low lung function and a tendency to develop hyperreactive airways with colds. Normal lung function by 11yrs).
2. Non-atopic wheezers (starts with symptomatic lower respiratory tract viral infection (RSV bronchiolitis) in early life, continue to wheeze beyond 3yrs, most outgrow condition and <1/3 develop atopic asthma).
Preschool wheeze = no inflammation between attacks and no known inflammation pattern.
3. IgE-associated wheeze/asthma (increases. Wheeze between colds, and wheeze attacks triggered by colds). [Pic]
Describe the changes in the lungs of an older child with atopic asthma.
Describe the treatment ladder for preschool wheeze treatment.
What delivery device are children given with their inhalers to help them use it properly?
What are 2 differential diagnoses of preschool wheeze?
Persistant inflammation throughout central and peripheral airways, denudation of airway epithelium, infiltration of lymphocytes and eosinophils.
Step 1: inhaled short acting beta-2 agonists. Step 2: add inhaled corticosteroids. Step 3: add leukotriene receptor antagonist. Step 4: specialist.
Spacer.
Bronchogenic cyst: large cystic abnormality -> early respiratory distress or later infection, or asymptomatic. Surgical removal. Thin walled with ciliated columnar lining, may contain cartilage and SM, some have gastro-oesophageal mucosa, air or fluid filed.
Congenital lobar emphysema: over distension of lobe, partial bronchial obstruction, ball valve effect
A normal bronchial biopsy is shown above, and one with a pathology below. What is the pathology, and list the changes.
Atopic asthma.
Normal: epithelium intact, no cellular infiltrate.
Asthmathic: goblet cell hyperplasia, thick sub basement membrane, cellular infiltrate.
