A comparison of pulse oximetry and cerebral oxygenation in children with severe sleep apnea-hypopnea syndrome: a pilot study.

Near infrared spectroscopy (NIRS) has been used to assess the impact of obstructive sleep apnea-hypopnea syndrome (OSAHS) on cerebral oxygenation. However, the relationship between the variations in the cerebral tissue oxygen saturation (ΔTOI) and pulse oximetry (ΔSpO ₂ ) has not been assessed in children with OSAHS. Consecutive clinically stable children with severe OSAHS [apnea-hypopnea index (AHI) >15 events h ^-1 ] diagnosed during a night-time polygraphy with simultaneous recording of cerebral oxygenation with NIRS (NIRO-200NX, Hamamatsu Photonics KK) were included between September 2015 and June 2016. Maximal ΔSpO ₂ (SpO ₂ drop from the value preceding desaturation to nadir) and concomitant variations in transcutaneous carbon dioxide (ΔPtcCO ₂ ), maximal ΔTOI and maximal variations in cerebral oxygenated (O ₂ Hb) and deoxygenated (HHb) haemoglobin were reported. The relationships between ΔSpO ₂ , ΔPtcCO ₂ and ΔTOI, ΔO ₂ Hb and ΔHHb were investigated. The data from five children (three boys, aged 9.6 ± 6.7 years, AHI 16-91 events h ^-1 ) were analysed. Strong correlations were found between ΔSpO ₂ and ΔTOI (r = 0.887, P < 0.001), but also with ΔO ₂ Hb and ΔHHb with a particular pattern in the youngest child with a dark skin pigmentation. Mean ΔSpO ₂ was 20 ± 17% and mean ΔTOI was 8 ± 7%. Maximal ΔSpO ₂ of approximately 70% were coupled with ΔTOI of no more than 35%. ΔPtcCO ₂ correlated only weakly with the cerebral oxygenation indexes. This pilot study shows a strong relationship between pulse oximetry and cerebral oxygenation in children with OSAHS, with lower changes in TOI compared to SpO ₂ . Future studies should address the clinical impact of respiratory events on cerebral oxygenation and its consequences.
(© 2017 European Sleep Research Society.)