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

Abstract

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