Assessment of portable oxygen concentrators in infants undergoing hypoxic challenge testing. A randomised controlled crossover trial

Abstract

Aim: Due to reduced PaO₂ , aircrafts at cruising altitudes are pressurised to a cabin altitude of 2438 m, equivalent to breathing FiO₂ 0.15. Portable oxygen concentrators (POCs) are approved for onboard oxygen supply with lack of evidence, especially in infants. We assessed POCs (continuous-flow cPOC vs. pulsed-flow pPOC) under simulated altitude conditions performing Hypoxic Challenge Testing (HCT).

Methods: In a randomised controlled crossover trial, we included patients <1 year born prematurely. In incidents of hypoxia (SpO₂ ≤ 85%), oxygen was administered through POC. In patients with a positive hypoxia reversal, HCT was repeated 24 hours later. If hypoxia occurred during the second testing, oxygen was given using the alternative POC.

Results: We randomised 26 patients; 22 patients received allocated intervention (4 dropped out). Mean gestational age 30.4 weeks, mean corrected age 38.2 weeks. Both POCs achieved immediate hypoxia reversal in all cases (SpO₂ cPOC/pPOC 98%/99.4% (95%CI -2.91, 0.01)) without any adverse events. No significant difference was observed in patients with BPD.

Conclusion: Both POCs generated sufficient oxygen to reverse HCT induced hypoxia. Although pPOCs are not recommended in paediatric age, our data suggest their effectiveness even in neonates without any associated adverse events. Future research on pPOCs safety is required to establish recommendations for their use.

Keywords: hypoxia altitude simulation test; hypoxic challenge testing; infants; neonates; portable oxygen concentrators.