Does therapeutic CPAP pressure correlate with OSA severity in children?

Objective/background: Continuous positive airway pressure (CPAP) is widely used to treat severe obstructive sleep apnea (OSA) in children. We observed that non polysomnography (PSG)-titrated CPAP pressures ranged close to 8 cmH2O in children with OSA. The aim of this study was to determine if there was a relationship between OSA severity, the age of the children and CPAP pressure. Methods: Children with OSA, comprising mainly children with complex OSA, who were started on constant CPAP, with no attended PSG according to our clinical practice, were included. CPAP pressure, baseline polygraphic and anthropometrics data were retrospectively collected. Results: Mean therapeutic CPAP pressure was 8 +/- 1 (range 6-12) cmH2O in 153 children treated with CPAP at a mean age of 3.7 +/- 3.4 (0.1-15.9) years. CPAP pressure slightly correlated with age at CPAP initiation (r = 0.226, p = 0.005), baseline mixed and obstructive apnea-hypopnea index (MOAHI; r = 0.185, p = 0.025), oxygen desaturation index (ODI; r = 0.300, p < 0.001), mean (r =-0.230, p = 0.005) and minimal pulse oximetry (SpO2; r =-0.318, p < 0.001). BMI z-score did not correlate with CPAP pressure, apnea-hypopnea index (AHI), MOAHI, nor ODI. CPAP pressure, AHI, MOAHI and ODI did not vary between age categories. Conclusions: A weak correlation was observed between therapeutic CPAP pressure and MOAHI in our cohort of children, with no correlation with BMI, highlighting the potential role of other factors, such as anatomical features. Future studies should confirm these findings with PSG-titrated CPAP pressures, and determine predictive factors for therapeutic CPAP. Predicting the level of CPAP may be relevant in clinical practice, as PSGtitrated CPAP procedure becomes more challenging.