Refining the Use of Nasal High-Flow Therapy as Primary Respiratory Support for Preterm Infants

Objective: To identify clinical and demographic variables that predict nasal high-flow (nHF) treatment failure when used as a primary respiratory support for preterm infants. Study design: This secondary analysis used data from a multicenter, randomized, controlled trial comparing nHF with continuous positive airway pressure as primary respiratory support in preterm infants 28-36 completed weeks of gestation. Treatment success or failure with nHF was determined using treatment failure criteria within the first 72 hours after randomization. Infants in whom nHF treatment failed received continuous positive airway pressure, and were then intubated if failure criteria were again met. Results: There were 278 preterm infants included, with a mean gestational age (GA) of 32.0 ± 2.1 weeks and a birth weight of 1737 ± 580 g; of these, nHF treatment failed in 71 infants (25.5%). Treatment failure was moderately predicted by a lower GA and higher prerandomization fraction of inspired oxygen (FiO₂): area under a receiver operating characteristic curve of 0.76 (95% CI, 0.70-0.83). Nasal HF treatment success was more likely in infants born at ≥30 weeks GA and with prerandomization FiO₂ <0.30. Conclusions: In preterm infants ≥28 weeks' GA enrolled in a randomized, controlled trial, lower GA and higher FiO₂ before randomization predicted early nHF treatment failure. Infants were more likely to be successfully treated with nHF from soon after birth if they were born at ≥30 weeks GA and had a prerandomization FiO₂ <0.30. However, even in this select population, continuous positive airway pressure remains superior to nHF as early respiratory support in preventing treatment failure. Trial registration: Australian New Zealand Clinical Trials Registry: ACTRN12613000303741.