Not all CPAP is equal

The question

Is "CPAP" one intervention, or do the device and nasal interface change what the baby actually receives?

The study

• An editorial by Aly and Mohamed in the Journal of Perinatology.
• It responds to Hillman et al., a retrospective study of 2,432 infants born before 33 weeks. That study compared two bubble CPAP interfaces, the RAM cannula and Babi.Plus, at different bottle pressures across the delivery room, the first 72 hours, after extubation, and at 31 weeks' postmenstrual age.

What they found

From Hillman et al.:

• RAM cannula at 5–6 cmH₂O had more CPAP failures than RAM at 7–8 cmH₂O or Babi.Plus at 5–6 cmH₂O.
• Babi.Plus at 5–6 cmH₂O had less CPAP failure in the first 72 hours in the NICU, while RAM at 7–8 cmH₂O had less in the delivery room.
• After extubation, fewer infants on Babi.Plus at 5–6 cmH₂O failed CPAP, because they had fewer apnea events.

From the editorial:

• In bubble CPAP, pressure is set by how deep the expiratory limb sits under water. It is transmitted inline to the prongs, giving a stable mean distending pressure with small oscillations from the bubbling.
• The RAM cannula is a flow-based interface with an intentional leak at the nostrils. The delivered pressure depends on flow and leak, so it is attenuated and variable. The setting on the dial does not guarantee a consistent airway pressure.
• The low chronic lung disease rates reported from Columbia in 1987 came from one consistent setup: bubble CPAP with short binasal prongs. Later trials rarely specified the device or interface and often grouped bubble and non-bubble systems together.

Where the evidence stops

• An editorial is expert opinion, and Hillman et al. is retrospective and observational, so neither can prove that one interface causes better outcomes.
• The idea that bubble oscillations affect breathing drive or lung stability is plausible but unproven. The authors call for direct airway pressure measurements.
• Their ask for future studies: report the device, interface and pressure, and measure the pressure that is actually transmitted.

References

1. Aly H, Mohamed MA. Not all CPAP is created equal: device architecture and interface mechanics. J Perinatol. 2026;46(10):2058–2059. doi:10.1038/s41372-026-02680-3 · PubMed 41957164
2. Hillman NH, Williams HL, Joshi SR, Herrmann LL, Claassen CC. Comparison of nasal interfaces and pressures during critical time-points in NICU: observation data from over 10 years. J Perinatol. 2026;46(10):2016–2022. doi:10.1038/s41372-026-02642-9 · PubMed 41912704

Independent educational content, not medical advice. Not affiliated with or endorsed by the AAP. Summaries reflect the published papers; read the originals before changing practice.