Research – bachbtrial.org.uk

Background to the research

Bronchiolitis is a chest infection usually caused by a virus and the most common virus causing bronchiolitis is called RSV (respiratory syncytial virus)

Almost 30,000 infants under the age of one are admitted to hospitals in England each year with bronchiolitis. Nearly half of all infants admitted to hospital with bronchiolitis will need help with their breathing because the oxygen levels in their blood is low (usually below 90%, compared to normal levels of around 95-98%). Oxygen support is usually started using thin tubes inserted into the nostrils (‘nasal cannula’). Most infants respond to nasal cannula oxygen alone, but some need additional breathing support.

If infants do not start to feel better after receiving oxygen through ‘nasal cannula’ oxygen (we call this moderate bronchiolitis), doctors and nurses will try other types of breathing support including moist oxygen (‘humidified oxygen’) and oxygen given through nasal cannula at a high flow rate (‘high-flow nasal cannula’, known as HFNC).

Humidified standard oxygen

High-flow nasal cannula

In infants with bronchiolitis who have severe breathing difficulties (we call this severe bronchiolitis), breathing support can be given with pressurised oxygen through tightly fitted prongs in the nose (known as CPAP) or using high-flow nasal cannula.

CPAP

High-flow nasal cannula (HFNC)

CPAP

High-flow nasal cannula (HFNC)

In infants with bronchiolitis who have severe breathing difficulties (we call this severe bronchiolitis), breathing support can be given with pressurised oxygen through tightly fitted prongs in the nose (known as CPAP) or using high-flow nasal cannula.

We are doing this research because there have been no studies comparing these different ways of providing breathing support and it is not clear which of these treatments should be started and when. Without evidence showing which method is the most effective, NHS staff use these methods interchangeably – meaning that the type of breathing support a child is given can be different between hospitals and depending on the preference of the doctors and nurses treating them. In recent years, the use of high-flow nasal cannula (providing warm, humidified oxygen at high flow rates) has become a widely used way of giving children breathing support as it is thought to be more comfortable for children and easy to use by staff. However, it does require specialist equipment and help from specialist nurses, and it may also mean children spend longer in hospital. HFNC has mostly replaced HSO in infants with moderate bronchiolitis and is also used in many hospitals as an alternative to CPAP in severe bronchiolitis. However, there is little research to show whether HFNC is better than HSO or CPAP.