BACKGROUND: High-flow nasal cannulae (HFNC) are gaining in popularity as a form 
of non-invasive respiratory support for preterm infants in neonatal intensive 
care units around the world. They are proposed as an alternative to nasal 
continuous positive airway pressure (NCPAP) in a variety of clinical situations, 
including post-extubation support, primary therapy from birth and 'weaning' from 
NCPAP.
OBJECTIVES: To present and discuss the available evidence for the use of HFNC in 
the preterm population.
METHODS: An internet-based literature search for relevant, original research 
articles (both randomised studies and not) on the use of HFNC in preterm infants 
was undertaken.
RESULTS: A total of 19 studies were included in the review. Distending pressure 
generated by HFNC in preterm infants increases with increasing flow rate and 
decreasing infant size and varies according to the amount of leak around the 
prongs. HFNC may be as effective as NCPAP at improving respiratory parameters 
such as tidal volume and work of breathing in preterm infants, but probably only 
at flow rates >2 litres/min. The efficacy and safety of HFNC in preterm infants 
remain to be determined.
CONCLUSIONS: There is growing evidence of the feasibility of HFNC as an 
alternative to other forms of non-invasive ventilation in preterm infants. 
However, there remains uncertainty about the efficacy and safety of HFNC in this 
population. Until the results of larger randomised trials are known, widespread 
use of HFNC to treat preterm infants cannot be recommended.