Hypoxic Challenge Testing in Infants; who is recommended in-flight oxygen?

Abstract

Introduction: BTS recommend infants with a history of neonatal chronic respiratory problems have hypoxic challenge testing (HCT) before air travel. SpO₂ <85% during HCT is recommended as a threshold below which in-flight oxygen is required and “paediatrician discretion should be used when SpO₂ between 85-90% and, where there is doubt, the doctor should err on the side of caution.” (BTS Thorax 2011;66 (suppl 1))

Aim: To establish which infants were recommended to fly +/- supplemental oxygen (suppO₂) following HCT.

Methods: During infant HCT SpO₂ is monitored in 15% FiO₂ within a body plethysmograph and suppO₂ administered if SpO₂ < 85%. If after 20 mins SpO₂ has remained >85% but <90% then suppO₂ is titrated to provide additional information. We reviewed data from infants (aged < 1 year) whom had HCT between March 2017-January 2020.

Results: Data collected from 65 infants, median age 27.6 weeks (range 5 to 51.6), 37 (57%) male. All had baseline SpO₂ ≥96% in room air.

SuppO₂ corrected SpO₂ in all to baseline. Of the 9 infants with SpO₂ 85-90% during HCT; 7 ex-preterm, 1 thymus transplant, 1 pulmonary hypertension with congenital diaphragmatic hernia. 8/9 infants had a flight recommendation post HCT. All 8 were advised by their clinician to use suppO₂ for air travel. The flight times in this subgroup ranged from 90 to 450 minutes.

Conclusion: Infants with baseline SpO₂ ≥96% may still exhibit SpO₂ desaturation during HCT. We found all paediatricians recommended in-flight oxygen for infants with HCT SpO₂ <90%. In the SpO₂=85-90% group, flight duration did not appear to affect the recommendation made.