Nocturnal pulse oximetry as a possible screening method for obstructive sleep apnea in infants with laryngomalacia

Laryngomalacia can be an important cause of obstructive sleep apnea (OSA) in infants. Nocturnal oximetry is a cheap and safe method in comparison to polysomnography for the detection of sleep-disordered breathing. The aim of this study is to evaluate the validity of nocturnal oximetry as a diagnostic tool for OSA in infants with laryngomalacia.

This retrospective study included infants with laryngomalacia and a clinical suspicion of OSA who underwent a polysomnography at the Antwerp University Hospital. The oximetry was rescored manually, blinded to the polysomnography results, according to four different scoring methods. An obstructive apnea-hypopnea index (oAHI) ≥ 2/h on polysomnography was used to define OSA.

This study included 53 patients with laryngomalacia (51% boys, mean age 3.72 ± 0.26 months). A diagnosis of OSA was established in 46 patients (87%) by polysomnography. Among the four different scoring methods, the scoring according to Brouillette et al., yielded the highest diagnostic accuracy with a sensitivity and specificity of 91% and 25% respectively and with a negative and positive predictive value of 25% and 91%, respectively. Correlations and the Bland-Altman plot showed a wide limit of agreement for laboratory polysomnography oAHI and nocturnal oximetry ODI.

Our data show that overnight pulse oximetry has a high sensitivity and PPV to diagnose OSA in infants with laryngomalacia. However, the low specificity and NPV indicate that PSG is still needed to exclude OSA in cases with normal oximetry.