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Observational study to define reference ranges for the 3% oxygen desaturation index during sleep in healthy children under 12 years using oximetry motion-resistant technology


Objective To define reference ranges for the 3% oxygen desaturation index (DI3) in healthy children under 12 years old during sleep.

Design Observational.

Setting Home.

Subjects Healthy children aged 6 months to 12 years of age.

Intervention Nocturnal pulse oximetry at home. Parents documented sleep times. Visi-Download software (Stowood Scientific) analysed data with artefact and wake periods removed.

Main outcome measures The following oximetry parameters used in the assessment of sleep-disordered breathing conditions were measured: 3% (DI3) and 4% (DI4) oxygen desaturation indices—the number of times per hour where the oxygen saturation falls by at least 3% or 4% from baseline, mean saturations (SAT50), minimum saturations (SATmin), delta index 12 s (DI12s), and percentage time with saturations below 92% and 90%.

Results Seventy-nine children underwent nocturnal home pulse oximetry, from which there were 66 studies suitable for analysis. The median values for DI3 and DI4 were 2.58 (95% CI 1.96 to 3.10) and 0.92 (95% CI 0.73 to 1.15), respectively. The 95th and 97.5th centiles for DI3 were 6.43 and 7.06, respectively, which inform our cut-off value for normality. The mean values for SAT50 and SATmin were 97.57% (95% CI 97.38% to 97.76%) and 91.09% (95% CI 90.32% to 91.86%), respectively.

Conclusion In children aged 6 months to 12 years, we define normality of the 3% oxygen desaturation index as <7 using standalone, motion-resistant pulse oximeters with short averaging times.

  • sleep
  • physiology

Data availability statement

All data relevant to the study are included in the article or uploaded as online supplemental information. Raw data are available from the corresponding author contactable by email.

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