3. Bronchiolitis

Question 1

Outline the pathophysiology of bronchiolitis

Answer 1

Commonly respiratory syncytial virus (RSV)

Bronchioles (<2mm)

• goblet cell prolif = excess mucus
• IgE type 1 allergic reaction = inflam
• constriction
• lymphocyte infiltration = oedema

All lead to ball-valve effect = hyperventilation, increased airway resistance, atelectasis, V/Q mismatch

Question 2

How does bronchiolitis present?

Answer 2

• low grade fever
• nasal congestion
• rhinorrhoea
• cough
• feeding diff

Exam = tachy, grunting, nasal flare, intercostal recessions, inspiratory crackles, expiratory wheeze, hyperinflation, cyanosis

Question 3

What is a DDx for suspected bronchiolitis?

Answer 3

Pneumonia

Croup

CF

HF

Bronchitis

Question 4

How should suspected bronchiolitis be Ix?

Answer 4

• Nasopharyngeal aspirate (RSV rapid testing)
• Blood/urine cultures if pyrexic
• FBC
• ABG
• CXR = hyperinflation, focal atelectasis, air trapping, flattened diaphragm, peribronchial cuffing

Question 5

Outline the best Mx for bronchiolitis

Answer 5

Urgent hospital = apnoea, looks seriously unwell, resp distress (grunting, recessions, RR >70), central cyanosis, sats <92%

• Oxygen (if sats <92%)
• Fluids if poor oral intake
• CPAP if impending resp failure
• Upper airway suctioning if secretions

NO ROLE FOR - Abx, steroids, bronchodilators

Question 6

List the possible complications of bronchiolitis

Answer 6

• hypoxia
• dehydration
• fatigue
• resp failure
• persistent cough/wheeze
• bronchiolitis obliterans (permanent damage)