High-flow nasal cannula (HFNC) therapy in hypoxic infants with bronchiolitis should only be used as a rescue therapy when standard subnasal oxygen has failed, according to new recommendations.

In an update to the Australasian bronchiolitis guidelines, the Paediatric Research in Emergency Departments International Collaborative (PREDICT) Network said HFNC was not currently recommended in the absence of hypoxaemia.

And in children with hypoxaemia, sub-nasal oxygen therapy should be the initial therapy, with only one third of children likely to require escalation to HFNC.

The latest recommendations were based on a systematic review of the evidence from 2000 to July 2018 – incorporating new data from three studies published since the 2015 cut-off for the ANZ guidelines.

The authors said HFNC use had become more common for respiratory support in infants outside the intensive care unit (ICU) setting.

In the two non-ICU trials, there was no difference in ICU admissions, intubation rates, duration of oxygen therapy or length of hospital stay between infants initially commenced on standard sub-nasal oxygen therapy and those commenced on HFNC.

However HFNC rescued or prevented ICU admission in 61% of 200 infants who failed standard sub-nasal oxygen.

Only one trial included a health economic analysis and found the most cost-effective treatment strategy was initial standard sub-nasal oxygen with rescue HFNC compared to initial HFNC therapy.

The authors noted response to standard subnasal oxygen therapy would not be immediate and clinicians should wait about four hours before escalating to HFNC.

“Given the ease with which care can be escalated to HFNC if needed, and that two thirds of infants in the largest studies did not require escalation past standard sub-nasal oxygen therapy, initial treatment for infants with bronchiolitis and hypoxemia should be sub-nasal oxygen therapy up to 2 L/min to maintain oxygen saturations, with HFNC reserved for cases of deterioration after the use of standard sub-nasal oxygen therapy.”

“The evidence from RCTs and health economic analysis undertaken to date does not support primary treatment with HFNC therapy in the emergency and ward setting.”

“If HFNC is ineffective in the ward setting, then transfer to a higher level of care and consideration of nCPAP appear to be reasonable next steps.”

“The use of HFNC for the work of breathing in the absence of hypoxemia, and severe disease is not currently supported by the evidence and should only be considered in the context of an appropriate research trial.”