Objective To compare the efficacy of low-flow oxygen, low-flow air and sham treatment given via nasal cannulae in preventing desaturation (falls in oxygen saturation (SpO₂)) in preterm infants.

Study design Infants born at <33 weeks gestation receiving gas at flow rates <1 l/min via nasal cannulae were eligible for inclusion. Enrolled infants received three treatments—0.1 l/min 100% oxygen, 0.1 l/min air, (21% oxygen) and sham (tubing disconnected from flow-meter)—via nasal cannulae, each for 3 h. Treatments were given in a randomly assigned order and caregivers were masked to treatment. Infants were monitored with a pulse oximeter that recorded SpO₂ and heart rate every 2 s. Treatment was stopped before 3 h if infants reached prespecified failure criteria. We compared the rates of failure and the frequency and duration of desaturation episodes that occurred during each treatment.

Results Of 14 infants enrolled, 2 (14%) reached failure criteria during treatment with oxygen compared with 7 (50%) during treatment with air and sham. Among infants who completed the 3-h study periods, there were fewer episodes and shorter duration of desaturation with oxygen compared with air and sham.

Conclusions At a flow rate of 0.1 l/min via nasal cannulae, air is no better than sham treatment in preventing desaturation in preterm infants, while 100% oxygen is superior to both.