The hypoxia challenge test does not accurately predict hypoxia in flight in ex-preterm neonates.
BACKGROUND
Air travel may pose risks to ex-preterm neonates due to the low oxygen environment encountered during flights. We aimed to study the utility of the preflight hypoxia challenge test (HCT) to detect in-flight hypoxia in such infants.


METHODS
Ex-preterm (gestation < or = 35 completed weeks) infants ready for air transfer from the intensive/special care nursery to regional hospitals were studied. A pretransfer HCT was performed by exposing infants to 14% oxygen for 20 min. Failure was defined as a sustained fall in pulse oxygen saturation (Spo(2)) < or = 85%. A nurse blinded to the test result monitored the in-flight oxygen saturations in each infant. If Spo(2) fell to < or = 85%, oxygen was administered.


RESULTS
Forty-six infants with median gestation of 32.2 weeks (range, 24 to 35.6 weeks) and birth weight of 1,667 g (range, 655 to 2,815 g) were recruited. No infants were receiving supplemental oxygen at the time of transfer. The HCT was performed at a median corrected age of 35.8 weeks (range, 33.1 to 43 weeks). Thirty-five infants (76%) passed the test, and the remainder failed. During the flight, 16 infants met the criteria for in-flight oxygen, but 12 of these infants (75%) had passed the preflight HCT. Of the 11 infants who failed the HCT, only 4 infants (36%) required in-flight oxygen. The HCT incorrectly predicted in-flight responses in 42% (19 of 46 infants).


CONCLUSIONS
A significant percentage of ex-preterm neonates require in-flight oxygen supplementation. The HCT is not accurate for identifying which infants are at risk for in-flight hypoxia.
Resnick
Steven M
SM
Neonatology Clinical Care Unit, King Edward Memorial Hospital for Women, Perth, WA, Australia. steven.resnick@health.wa.gov.au
Hall
Graham L
GL
Simmer
Karen N
KN
Stick
Stephen M
SM
Sharp
Mary J
MJ
D000337:Aerospace Medicine; D000531:Altitude; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis* / Q000503:physiopathology / Q000517:prevention & control; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000503:physiopathology; D008171:Lung Diseases / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D010102:Oxygen Inhalation Therapy; D012372:ROC Curve; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D014195:Travel