RESUMO
BACKGROUND: During air flight, cabin pressurisation produces an effective fraction of inspired oxygen (FiO(2)) of 0.15. This can cause hypoxia in predisposed individuals, including infants with bronchopulmonary dysplasia (BPD), but the effect on ex-preterm babies without BPD was uncertain. The consequences of feeding a baby during the hypoxia challenge were also unknown. METHODS: Ex-preterm (without BPD) and term infants had fitness to fly tests (including a period of feeding) at 3 or 6 months corrected gestational age (CGA) in a body plethysmograph with an FiO(2) of 0.15 for 20 min. A 'failed' test was defined as oxygen saturation (SpO(2)) <90% for at least 2 min. RESULTS: 41 term and 30 ex-preterm babies (mean gestational age 39.8 and 33.1 weeks, respectively) exhibited a significant median drop in SpO(2) (median -6%, p<0.0001); there was no difference between term versus ex-preterm babies, or 3 versus 6 months. Two term (5%) and two ex-preterm (7%) babies failed the challenge. The SpO(2) dropped further during feeding (median -4% in term and -2% in ex-preterm, p<0.0001), with transient desaturation (up to 30 s) <90% seen in 8/36 (22%) term and 9/28 (32%) ex-preterm infants; the ex-preterm babies desaturated more quickly (median 1 vs 3 min, p=0.002). CONCLUSIONS: Ex-preterm babies without BPD and who are at least 3 months CGA do not appear to be a particularly at-risk group for air travel, and routine preflight testing is not indicated. Feeding babies in an FiO(2) of 0.15 leads to a further fall in SpO(2), which is significant but transient.
