Objective Compare rates of hypoxaemia during transpyloric and gastric feedings in very preterm infants with severe bronchopulmonary dysplasia.

Design N-of-1 multiple crossover trials with individual patient and pooled data analyses.

Setting Level IV intensive care nursery.

Patients Infants receiving positive airway pressure between 36 and 55 weeks postmenstrual age were enrolled between December 2014–July 2016.

Intervention N-of-1 trial consisting of two blocks, each with a 4-day gastric and 4-day transpyloric feeding period assigned in random order.

Main outcome measures The primary outcome was the frequency of daily intermittent hypoxaemic events (SpO₂ ≤80% lasting 10–180 s). Secondary outcomes included the daily proportion of time with an SpO₂ ≤80% and mean daily fraction of inspired oxygen.

Results Of 15 infants, 13 completed the trial and 2 stopped early for transient worsening in respiratory status during gastric feedings. In the intention-to-treat analyses, transpyloric feedings resulted in increased rates of intermittent hypoxaemia in five infants, greater time per day in hypoxaemia in three infants and more supplemental oxygen use in three infants. One infant received more supplemental oxygen during gastric feedings. The remaining study outcomes were similar between the feeding routes in all other infants. Pooling all data, transpyloric feedings resulted in a higher frequency of intermittent hypoxaemic events (median 7.5/day (IQR 1–23.5) vs 3/day (1–11); adjusted incidence rate ratio 1.8, 95% CI 1.3 to 2.5) and a greater proportion of daily hypoxaemia time (median 0.8% (IQR 0.1–2.3) vs 0.4% (0.07–1.8); adjusted mean difference 1.6, 95% CI 1.1 to 2.5).

Conclusions Transpyloric compared with gastric feedings modestly increased rates of hypoxaemia among study participants.

Trial registration number NCT02142621