Predictive equation for optimal Continuous Positive Airway Pressure (CPAP) in children with Obstructive Sleep Apnoea (OSA)

Abstract

Introduction: A subgroup of children with OSA requires treatment with CPAP. Mathematical equations to predict optimal CPAP have been developed for adults but not children.

Aim: To determine the correlation between optimal CPAP, clinical and polysomnography (PSG) variables in children with OSA; and to develop a predictive equation for optimal CPAP.

Methods: This was a retrospective study of children with OSA who underwent CPAP titration studies. Patients with craniofacial abnormalities (except Down syndrome [DS]) and neuromuscular diseases were excluded. PSGs were done using Sandman Elite™ sleep diagnostic system. Correlations between optimal CPAP, clinical and PSG variables were analysed. A multivariable linear regression model for optimal CPAP was developed.

Results: 198 children (mean±SD age=13.1±3.6 years) were studied. Optimal CPAP had a significant positive correlation with age (rho=0.216, p=0.002), Obstructive Apnoea Hypopnoea Index (OAHI) (rho=0.421, p<0.001), Oxygen Desaturation Index (ODI) (rho=0.417, p<0.001), Rapid Eye Movement Respiratory Disturbance Index (REM RDI) (rho=0.378, p<0.001) and Body Mass Index (BMI) z-score (rho=0.160, p<0.024); and a significant negative correlation with SpO₂ nadir (rho=−0.333, p<0.001). The predictive equation derived was: Optimal CPAP (cm H₂O) = 4.538 +(0.250 × age [years]) −(0.549 [for females]) −(0.752 [if no adenotonsillectomy done]) +(2.125 [for DS]) +(0.040 × OAHI) +(0.337 × BMI z-score), (adjusted R²=0.307, p<0.001).

Conclusions: The predictive equation developed may help determine optimal CPAP in children with OSA. Further studies are required for validation and to determine its applicability in different populations.