Tertiary care hospital.Patients
Thirty-three former premature infants (28.3 +-/2.3 weeks gestation), aged 5 to 7 years, who were participating in a follow-up study, were enrolled in this study.Design
The study compared the 88%-SAT with standard spirometry and respiratory health characteristics ascertained through a parental questionnaire. The 88%-SAT consists of continuous measurement of hemoglobin saturation by pulse oximetry (SaO2) while the subject breathes a nonhumidified 12% oxygen and nitrogen mixture for 10 minutes or until SaO (2) decreases to 88%, whichever occurs first. Abnormal 88%-SAT was defined as a decrease of SaO2 to 88% within the 10-minute period, and abnormal spirometry was defined using standardized values.Results
Of the 20 children who successfully completed both spirometry and the 88%-SAT, 10 had normal spirometry results and did not desaturate to 88%, and 5 had abnormal spirometry and 88%-SAT results. Four children did not desaturate during the 88%-SAT, but had abnormal spirometry results, and one child had abnormal 88-SAT results, but normal spirometry.Conclusions
Our data suggest that the 88%-SAT may be more effective than spirometry for identifying reactive airways disease in young, uncooperative, or developmentally delayed children. The dry air of the hypoxic inspired gas may function as an airway challenge, leading to decreased oxygenation in patients with reactive airways. Pediatrics 1994;93:63-67; pulmonary function testing, bronchial challenge.