Nocturnal oximetry in children with obstructive lung disease or sleep-disordered breathing.

OBJECTIVES: Although progress has been made in the standardized interpretation of nocturnal oximetry in children with obstructive sleep-disordered breathing (SDB), no evidence exists on oximetry abnormalities in other respiratory disorders. We aimed to compare obstructive lung disease (OLD) and SDB regarding nocturnal oximetry parameters.

METHODS: We analyzed oximetry recordings from children with (i) OLD (obliterative bronchiolitis; cystic fibrosis); (ii) snoring and adenotonsillar hypertrophy (SDB); and (iii) no respiratory disorder (controls). The three groups were compared regarding: (i) oxygen desaturation of hemoglobin index (SpO2 drops ≥3%/h-ODI3) and (ii) basal SpO2 (average SpO2 between SpO2 drops). The associations of oximetry parameters (natural logarithm) with study group were tested using linear regression including age as covariate.

RESULTS: Data of 16 subjects with OLD (median age: 7.3 years; Q25, Q75: 5.4, 12), 22 children with SDB (6.3 years; 4, 9) and 22 controls (6.8 years; 5.6, 10.3) were analyzed. Children with OLD or SDB had significantly lower basal SpO2 than controls (91.9% [90.8, 93.4] vs 96.3% [96, 97.4] vs 97.6% [97.1, 97.9]; P < 0.01). No subjects in the SDB or control groups had basal SpO2  < 95%. Children with SDB had significantly higher ODI3 than children with OLD or controls [8.4 episodes/h (6.2, 16.6) vs 4.4 episodes/h (3.6, 6.6) vs 2 episodes/h (1.3, 2.7); P < 0.01]. OLD had the greatest negative effect on basal SpO2 (R2  = 0.62; P < 0.001) and SDB the greatest positive effect on ODI3 (R2  = 0.34; P < 0.001).

CONCLUSION: OLD is associated mostly with reduced basal SpO2 , whereas SDB is characterized by elevated ODI3.