Bronchiolitis

Bronchiolitis

Bronchiolitis is an acute, self-limiting viral infection of the lower respiratory tract that affects infants under 12 months, with a peak incidence between 3 and 6 months. It’s the most common reason for paediatric hospital admission in the UK, especially during the winter months (October to March). The most frequent cause is Respiratory Syncytial Virus (RSV), but other viruses like Rhinovirus and Parainfluenza can also be responsible.

History

The illness typically starts with an upper respiratory tract infection (URTI) with coryza and cough. This is followed by increasing breathlessness and noisy breathing, with the child appearing wheezy. Key historical points to ask about include:

  • Feeding: Poor feeding is a major red flag, especially if the infant is taking less than 50% of their usual intake.

  • Apnoeas: Episodes of apnoea (temporary cessation of breathing) are a significant concern, especially in infants under 6 months.

  • Risk Factors: Identify any high-risk factors for severe disease, such as prematurity, chronic lung disease, congenital heart disease, or a neuromuscular disorder.

 

Examination

A thorough examination is crucial to assess the severity of the illness and the risk of deterioration.

  • Vital Signs: Check respiratory rate, heart rate, and oxygen saturation (SpO2).

  • Work of Breathing: Look for signs of increased work of breathing, such as nasal flaring, subcostal and intercostal recession, and grunting (an expiratory sound).

  • Auscultation: On chest auscultation, the classic findings are fine inspiratory crackles and expiratory wheeze.

  • Hydration: Assess for signs of dehydration, as poor feeding is common.

 

UK Management and Guidelines

Management of bronchiolitis in the UK is primarily supportive, as there is no specific treatment for the virus. The goal is to maintain oxygenation and hydration while the body clears the infection.

 

Criteria for Admission

NICE guidelines recommend admission if the child has any of the following:

  • Risk Factors for Severe Disease: Infants under 3 months, pre-term birth, or an underlying cardiorespiratory or neuromuscular condition.

  • Clinical Signs of Severity:

    • Signs of respiratory distress: Persistent grunting or severe recession.

    • Apnoeas: Any history of apnoea.

    • Low Oxygen Saturation: A persistent SpO2 of less than 92% in air.

    • Poor Feeding: Taking less than 50% of normal feeds.

  • Social Circumstances: If the parents are unable to cope or there are concerns about their ability to provide care at home.

 

Discharge Criteria

A child can be discharged home when they are clinically stable and their parents are confident in managing them.

  • They should be older than 6 months and have no significant risk factors.

  • They should be able to feed adequately.

  • Their SpO2 should be consistently above 92% in room air.

  • Parents should be given clear instructions on what to look for and when to return to the hospital (safety-netting advice).

 

Investigations

Routine investigations are not recommended for a clear clinical diagnosis of bronchiolitis.

  • Viral Swabs: Not needed for management but are useful for infection control.

  • Chest X-ray: Only performed if there is diagnostic uncertainty or a suspicion of a secondary bacterial infection.

  • Blood Tests: Rarely needed unless there are signs of a secondary bacterial infection or sepsis.

 

Hospital Management

  • Supportive Care:

    • Oxygen: Give oxygen to maintain an SpO2 of greater than 90-92%.

    • Feeding and Hydration: Encourage small, frequent oral feeds. If a child cannot feed adequately, nasogastric tube (NGT) feeding or intravenous fluids may be needed.

  • High-Flow Nasal Cannula (HFNC): In children with moderate to severe respiratory distress, HFNC is often used to provide a comfortable level of respiratory support.

  • Non-Invasive Ventilation (CPAP) or Ventilation: These are reserved for children who are deteriorating or have impending respiratory failure.