Usefulness of desaturation index for the assessment of obstructive sleep apnea syndrome in children

Abstract

Objective: Obstructive sleep apnea syndrome (OSAS) can result in learning, behavioral, and even growth problems in children. Overnight polysomnography (PSG) is the gold standard for the diagnosis of OSAS, but this diagnostic technique is time consuming and inconvenient. It is well documented that patients with OSAS experience oxygen desaturation during sleep. The purpose of this study was to determine if the level of oxygen desaturation can be used to predict OSAS in children.

Methods: This retrospective study included 148 children aged from 3 to 12 years; all were snorers and were suspected of having OSAS. Objective PSG parameters, nocturnal pulse oximeter data and subjective modified Epworth Sleepiness Scale (ESS) scores were assessed. Mild, moderate, and severe OSAS was classified as apnea-hypopnea index (AHI)≥1 and <5, AHI≥5 and <10, and AHI≥10, respectively.

Results: Of the 148 children, 130 (87.8%) were diagnosed with OSAS. There was no correlation between the AHI and the modified ESS score (r = -0.048, p = 0.563). The desaturation index (DI) had the highest correlation with AHI (r = 0.886, p < 0.001). Using the DI cut-off values of 2.05 to predict OSAS in children had good positive predictive value of 98.1%. The optimal DI cut-off values for predicting the occurrence of mild, moderate, and severe OSAS were 2.05 (sensitivity: 77.7%; specificity: 88.9%), 3.50 (sensitivity: 83.8%; specificity: 86.5%) and 4.15 (sensitivity: 89.1%; specificity: 86.0%), respectively.

Conclusions: These findings suggest that DI, as determined using a nocturnal pulse oximeter, may be a good tool for predicting both the presence and the severity of OSAS in children.

Keywords: Desaturation index; Obstructive sleep apnea syndrome (OSAS); Polysomnography; Pulse oximetry.