15.3.3 Recurrent Lower Airway Cough/wheeze Flashcards
Wheeze
Def
Physiology
Def
- Musical sounds produced by oscillations of narrowed airway {whistle in chest}
- Mostly during expiration (very unlikely inspiration)
- Indicates intrathoracic obstruction to airflow = airway obstruction
- polyphonic or monophonic
Physiology
- Wheeze = airway obstruction
- Obstruction relates to airway diameter
- immature airways of infants more prone to collapse
Common causes of recurrent wheezing in young children
Divide into large and small airways to find site of obstruction
- Asthma (very common)
- Post-viral wheezing (transient or episodic viral wheezing)
- Congenital lung abnormalities
- TB (lymph nodes obstructing airways)
- Gastro-oesophageal reflux
- Cystic fibrosis (rare)
- Immune deficiency (rare)
- Cardiac failure (rare)
Age determines the cause you have
Slide 7
Aetiology of airway obstruction
- Large airway obstruction = single site of obstruction = monophonic wheeze (single pitch)
- Peripheral airway obstruction = multiple sites of obstruction = polyphonic wheeze
When is a wheeze not asthma
- Presence of other constitutional or systemic signs and symptoms, e.g.
➡️Stridor
➡️Failure to thrive
➡️Vomiting with feeds
➡️Clubbing - Onset of symptoms in very young child (from 5 years)
- Persistent wheeze
- Poor response to asthma treatment
Large airway vs small airway obstruction
Signs and Symptoms
- Symptoms varies according to the degree of airway obstruction.
- Children frequently present with a persistent unremitting cough often with associated large airway wheezing or stridor.
- Classically, large intrathoracic airway obstruction presents with monophonic wheezing
- Hyperinflation and subcostal retraction are not as prominent as in small airway obstruction.
- Audible on one side of the chest or on both sides depending on the area and the degree of obstruction.
- often confused with asthma, but these children will not respond to inhalation steroids and the airway obstruction might be worsened by β2 agonist
Peripheral (small) airway obstruction
Epidemiology
Risk factors
- More common in young
- Up to 30% wheeze in 1st year of life, >60% by 3 years of age
Risk factors:
- Environmental: Crowded living space {infec}, tobacco smoke exposure, air pollution
- Premature birth
Bronchiolitis
Slide 16
- driven by virus, most common RSV
- syndromic diseases
- common in winter
- no specific treatment
- unsolved problem
- most common cause of wheezing in young children
Small airway obstruction differential diagnosis
- Aspiration syndromes
- Immunodeficiency: primary/acquired
- Mucociliary clearance abnormality (rare)
➡️Cystic fibrosis (very early in childhood; fam history)
➡️Primary Ciliary dyskinesis (laterality defects)
Intrathorvacic large airway obstruction
Acquired
- Foreign body aspiration
- PTB
- Lymphoma
- Tumours
- Viral papilomata
Congenital airway/extrinsic compression
- Tracheo-bronchomalacia
- Tracheal stenosis / web
- Vascular compression
- Bronchogenic cyst
- Mediastinal masses
➡️Teratoma
➡️Germ cell tumors
➡️Foregut duplication cysts
Airways obstruction causes (ball-valve effect)
Outside lumen :
- TB glands
- Lymphoma
- Bronchogenic cyst
- Vascular compression
Luminal obstruction:
- Foreign body
- Tumor
**Lumen wall:*
- Bronchomalacia
Acquired causes of airway obstruction in children
Clinical presentation
Depends on
- The degree of airway narrowing
- Whether infected gland has infiltrated the airway wall,
- Herniated into the lumen and discharged caseous material into the lumen of the airway.
Progression
- As the obstruction increases, a ‘ball valve effect’ which leads to an unilateral hyperinflation of the lobe or lung can develop.
- If the obstruction is complete collapse of a lobe or segment of a lobe occurs.
- Ulceration of the lymph gland into the airway can lead to inhalation of tuberculous material.
ACQUIRED: PTB
- Lymph gland disease involving the airways is common following primary infection in children younger than 5 years of age where the small airway size makes young children vulnerable
- The exact incidence of children with airway obstruction due to primary tuberculosis in the chemotherapeutic era is not known.
- The incidence of complicated lymph node disease in 2 recent reports varied from 8-38% in children less than 15 years of age.
- During adequate anti-tuberculosis treatment the size of the lymph nodes may increase and airway obstruction worsen. This has also been seen in children on TB and anti- retroviral drugs
- Luminal involvement of the airway is very rare in children. In these cases the lumen of the airway is involved and airway disease is not caused by external compression or because glands have herniated into the airways
Clinical findings
1. Airway compression
2. Unilateral hyperinflation
3. Expansile pneumonia
Viral Papilomata
- Child infected in the birth canal
- recurrent and very difficult to treat
Congenital causes of airway obstruction in children
- Vascular anomalies causing tracheal compression (double aortic arch, right aortic arch with left patent ducturs arteriosus aor ligamentum arteriousum)
- inmominate arterial compression (most common)
- left pulmonary sling
Continue on slide 45
Vascular compressio
- Vascular compression of the airways were observed in 13% - 26% of children , who underwent bronchoscopy for persistent wheezing , stridor and apnea
- 11 -15 % of persistently wheezing children in whom bronchoscopy was performed had bronchomalacia or narrowing of the left main-stem bronchus
