Background and aims Low flow oxygen can be delivered either as a dry or heated humidified gas. Little evidence exists about which is most beneficial to the paediatric patient. The aim of the study is to investigate whether children aged < 2 years with acute respiratory illness requiring low flow oxygen (< 2 litres) would benefit from heated humidified oxygen when compared to dry oxygen therapy.

Methods A prospective randomised controlled pilot study of 117 children aged < 2 years with an acute respiratory illness requiring low flow oxygen therapy. 54 participants were randomised to receive dry oxygen and 63 participants were randomised to receive heated humidified oxygen. Hours on oxygen therapy, hours to ready to discharge and hours to hospital discharge were recorded.

Results Median hours on dry oxygen therapy totalled 43 hours versus 39 hours in the heated humidified oxygen group. Wilcoxon rank test (p=0.05) returned P value 0.77. Hours from randomisation to ready to discharge equated to 66 hours dry oxygen and 52 hours heated humidified oxygen. Wilcoxon rank test (p=0.05) calculated p=0.36. The total median length of hospital stay was 53 hours in the dry oxygen group and 47 hours in the heated humidified oxygen group. Wilcoxon rank test (p=0.05) determined p=0.70.

Conclusion No statistically significant difference in hours on oxygen therapy, time to ready to discharge and length of hospital stay between the dry oxygen and heated humidified group. No significant benefit to the administration of heated humidified oxygen at low flows was found.