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


CONCLUSIONS
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.
Martin
Andrew C
AC
School of Paediatrics and Child Health, University of Western Australia, Perth, WA, Australia. andrew.martin@health.wa.gov.au
Verheggen
Maureen
M
Stick
Stephen M
SM
Stavreska
Vaska
V
Oostryck
Jan
J
Wilson
Andrew C
AC
Hall
Graham L
GL
D000401:Aircraft; D000531:Altitude; D016022:Case-Control Studies; D002675:Child, Preschool; D002908:Chronic Disease; D017408:Guidelines as Topic; D006801:Humans; D000860:Hypoxia / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D007223:Infant; D007231:Infant, Newborn; D008171:Lung Diseases / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000097:blood*; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors
D010100:Oxygen