Does Patient’s Initial Evaluation Predict a Change in Optimal Pressure on CPAP Retitration?

Introduction: Only vindication of a nasal continuous positive airway pressure (CPAP) retitration procedure will be an actual change in the optimal CPAP pressure after that test. The purpose of this study was to identify any items in patient characteristics, clinical features, baseline PSG and initial CPAP titration as predictors of change in optimal pressure on CPAP retitration. Methods: 46 patients with obstructive sleep apnea (OSA) were divided in two groups: Group I (optimal pressure was changed on CPAP retitration): N = 30, M 22 and F 8, age 31 72, BMI 26 50 Kg/m, neck size 15 – 20", tonsillectomy in 8, narrow oropharynx in 15, uvuvlopalatopharyngoplasty (UP3) in 2, abnormal chin in 3, deviated nasal septum (DNS) and prior nose surgery in 1 each, initial CPAP pressure 6 19 cm, sleep efficiency 65% 98%, REM latency 0 304 minutes and residual apnea hypopnea index (AHI) 0 23/hour. Group II (optimal pressure unchanged after CPAP retitration): N = 16, M 11 and 5 F, age 32 69, BMI 23 62 Kg/m, neck size 14.5 20", tonsillectomy in 6, narrow oropharynx in 5, abnormal chin in 4, corrective nasal surgery in 2, DNS in 1, initial CPAP pressure 8 13 cm of H2O, sleep efficiency 69% 95%, REM latency 0 270 minutes and residual AHI 0 19/hour. The statistical analyses were performed using two-tailed Fisher’s t test and unpaired t test. A p value of <0.05 was considered statistically significant. Results: Patient characteristics (age, gender, neck size, and BMI), clinical features (tonsillar status, oropharyngeal narrowing, chin abnormality, DNS/nasal surgery or UP3), baseline PSG or initial CPAP titration (sleep efficiency, REM latency, residual AHI and initial CPAP pressure) did not differ significantly between the 2 groups (p = 0.09 0.99). Conclusion: Patient characteristics, clinical features or variables on baseline PSG and initial CPAP titration do not predict a change in optimal pressure on CPAP retitration. The results suggest that 1) Significant weight change; 2) Patient’s subjective feeling of pressure being too high or insufficient; 3) Residual or recurrent daytime sleepiness uncorrected by interface readjustments; 4) Post-operative evaluation after palliative UP3 Maxillomandibular advancement or tonsillectomy and adenoidectomy; and 5) Annual retitrations in high risk occupations (e.g. truck driver or pilot) are the best current, empiric and clinical guidelines for CPAP retitration.