Bronchiolitis

Question 1

Pathology

Answer 1

• Viral small airway respiratory infection
• Viral spread through respiratory secretions, contaminated hands = infects lower respiratory tract cells, leading to natural killer cells attack and cytokines being released. Epithelial cells produce mucus, vessels vasodilate and fluid leaks, walls swell and airway narrows

Question 2

Causes

Answer 2

• Respiratory syncytial virus (RSV) = most common especially during winter
• Adenovirus, human bocavirus, human metapneumovirus
• Mycoplasma pneumoniae

Question 3

Risk factors

Answer 3

• Young age (children < 2 years old)
• Previous infection
• Daycare attendance
• Neuromuscular disorders
• Premature births
• Exposure to smoking

Question 4

Signs and symptoms

Answer 4

• Congestion, sore throat, cough
• Hypoxia –> tachycardia
• If severe = dyspnea, wheezing, central apnea (brief periodic breathing arrest), nasal flaring, fever…

Question 5

Diagnosis

Answer 5

• X-ray = patchy infiltrates, atelectasis

Lab results
- Positive rapid viral testing (RT-PCR) = suggests viral infection

Question 6

Treatment

Answer 6

• Palivizumab = monoclonal antibody against RSV given monthly throughout RSV season for prematurely-born infants, chronic lung disease and congenital heart disease
• Heated, humidified supplemental oxygen
• Intubation (if hypoxia continues despite intervention)