Sleep disordered breathing and sleep quality in children with bronchiolitis obliterans

The incidence of sleep-disordered breathing (SDB) increases in chronic lung diseases. Our aim was to evaluate SDB and sleep quality in children with postinfectious bronchiolitis obliterans (BO) and assess associated risk factors. We hypothesized that children with BO are at increased risk for SDB and have impaired sleep quality. We also hypothesized that severity of SDB and impairment of sleep quality is related to the severity of lung disease. Sleep Related Breathing Disorder (SRBD) subscale of the Pediatric Sleep Questionnaire (PSQ) and Pittsburgh Sleep Quality Index (PSQI) questionnaires; spirometry, impulse oscillometry (IOS), and overnight polysomnography (PSG) were performed. Twenty-one patients (14 male, median age: 8.3 years) were enrolled. Five patients (25%) had a PSQ score of >0.33, predictive of a SDB. Ten patients (48%) had poor sleep quality. Four patients (19%) had an OAHI of >1/hr. Nineteen patients (90%) had a high desaturation index. Four patients (19%) had a mean oxygen saturation of <93%. Median central apnea time was 7.5 (IQR: 6.9-9.1) seconds. Central apnea index of the patients correlated positively with R5, R10, R15, R20, Z5, and negatively with X10 and X15 at IOS. There was a positive correlation between the lowest oxygen saturation and FVC, FEV1 , X5, X10, X15, X20 while there was a negative correlation between lowest saturation and the central apnea index at PSG, R5, R10, and Z5 at IOS. Mean oxygen saturation during PSG correlated positively with FVC, FEV1, FEF(25-75), X5, X10, X15, X20 results. The risk of nocturnal hypoxia is increased in patients with BO and correlated to the severity of lung disease determined by pulmonary function tests. Although BO patients have a shorter duration of central apneas, they are more prone to desaturate.