High-flow nasal oxygen for children's airway surgery to reduce hypoxaemic events
A randomised controlled trial
The Lancet Respiratory Medicine
Submitted November 2024 by Dr Richard Barnes
Read by 134 Journal Watch subscribers
This prospective randomised trial was conducted in five tertiary Australian paediatric centres. The trial compared two techniques of oxygen delivery during tubeless ENT airway surgery in children aged 0-16 years: standard care with oxygen flows of up to 6l/min by oral or nasal catheter; or trial care with nasal high-flow oxygen at 2L/kg/min in younger children, up to a maximum of 50L/min in older patients.
The primary outcome was the need to interrupt surgery for rescue oxygenation. Secondary outcomes most importantly included degree and duration of any hypoxaemia. Data for 528 children were analysed. The recruitment number was calculated according to a power analysis based on a halving of the rate of the primary outcome with high-flow.
The primary outcome – surgical care without need for interruption – occurred in 88% of patients in both groups. There were no significant differences in any of the secondary outcomes. The statistics were not designed to look for a true “no difference”, but the numbers strongly suggest this to be the case.
This study represents a great deal of work by a large group of investigators. It is also, as Engelhardt and Disma put it in an accompanying editorial, a “testament to the clinical skills and expertise of the participating Australian tertiary paediatric centres, which are able to provide care with either technique in these patients with frequently complex and challenging conditions.” Interestingly, the 12% incidence of the need to interrupt surgery observed in both group is half what had been anticipated based on a preliminary pilot study of 78 children. One wonders whether the research brought about a Hawthorne effect.
The study shows conclusively that nasal high-flow oxygen delivery confers no advantage over standard care for the challenging field of paediatric tubeless ENT airway surgery. In my opinion, standard care continues to offer certain advantages: the ability to deliver sevoflurane (which was chosen either alone or in combination with intravenous anaesthesia in half the standard care cases); and the ability to deliver positive pressure without surgical interruption. From the resource point of view, standard care is simpler and less costly.
Nasal high-flow oxygen has swept across the anaesthetic world over the past decade, for both adult and paediatric patients, in a variety of settings involving both apnoea and spontaneous ventilation. This study adds to the accumulating data-bank of situations in which the technique’s promise does not match the reality.
