Definition of cutoff values for the hypoxia test used for preflight testing in young children with neonatal chronic lung disease

Chest. 2008 Apr;133(4):914-9. doi: 10.1378/chest.07-1198. Epub 2007 Sep 21.


Background: The hypoxia test can be performed to identify potential hypoxia that might occur in an at-risk individual during air travel. In 2004, the British Thoracic Society increased the hypoxia test cutoff guideline from 85 to 90% in young children. The aim of this study was to investigate how well the cutoff values of 85% and 90% discriminated between healthy children and those with neonatal chronic lung disease (nCLD).

Methods: We performed a prospective, interventional study in young children with nCLD who no longer required supplemental oxygen and healthy control subjects. A hypoxia test (involving the administration of 14% oxygen for 20 min) was performed in all children, and the nadir in pulse oximetric saturation (Spo(2)) recorded.

Results: Hypoxia test results were obtained in 34 healthy children and 35 children with a history of nCLD. Baseline Spo(2) in room air was unable to predict which children would "fail" the hypoxia test. In those children < 2 years of age, applying a cutoff value of 90% resulted in 12 of 24 healthy children and 14 of 23 nCLD children failing the hypoxia test (p = 0.56), whereas a cutoff value of 85% was more discriminating, with only 1 of 24 healthy children and 6 of 23 nCLD children failing the hypoxia test (p = 0.048).

Conclusion: In the present study, using a hypoxia test limit of 90% did not discriminate between healthy children and those with nCLD. A cutoff value of 85% may be more appropriate in this patient group. The clinical relevance of fitness to fly testing in young children remains to be determined.

MeSH terms

  • Aircraft*
  • Altitude*
  • Case-Control Studies
  • Child, Preschool
  • Chronic Disease
  • Guidelines as Topic
  • Humans
  • Hypoxia / blood*
  • Hypoxia / diagnosis*
  • Hypoxia / etiology
  • Infant
  • Infant, Newborn
  • Lung Diseases / blood*
  • Lung Diseases / complications
  • Lung Diseases / diagnosis
  • Oximetry / methods
  • Oxygen / blood*
  • Prospective Studies
  • Reference Values
  • Risk Factors


  • Oxygen