Oxygen desaturation indices as a predictor for obstructive sleep apnoea in children

Introduction: Nocturnal pulse oximetry (NPO) is sometimes used to diagnose obstructive sleep apnoea (OSA). This study aimed to determine if oxygen desaturation indices (ODI) accurately predict OSA. Methods: Typically developing (TD) children (1-15.99yrs) referred to evaluate OSA were recruited retrospectively from 3 UK tertiary sleep units between May 2016-May 2021. All underwent NPO using an oximeter with a 2s averaging time alongside cardiorespiratory polygraphy (CRP). Exclusion criteria were: obesity with a standard deviation score >3, known haemoglobin disorders, CRP conducted on respiratory support, acquisition of <4 hours of artefact free data. Receiver operating characteristic curves determined optimum ODI3 and ODI4 for predicting an obstructive apnoea hypopnoea index (oAHI) ≥ 1, 5 and 10. Results: 322 TD children, 197 boys (61.2%), median age 4.9 yrs (range 1.1 -15.5 yrs) were included. oAHI was < 1 in 178 (55.3%) cases, ≥1 in 144 (44.7%), ≥5 in 61 (18.9%) and ≥10 in 28 (8.7%) cases. Area under the curve values were acceptable for oAHI ≥1 and excellent for oAHI ≥5 and 10. Optimum combined sensitivity and specificity are highlighted below. Conclusion: In typically developing children, ODI3 ≥ 6 and ODI4 ≥ 4 provide optimum sensitivity and specificity for diagnosing OSA. Higher ODI3 and ODI4 values better predict severe OSA.