1194 A Case of Unsuccessful Positive Airway Pressure Titration

Abstract Introduction Oronasal masks are commonly used interfaces when treating obstructive sleep apnea (OSA). Masks modalities are often chosen based on patient preference and comfort however, oronasal masks may cause worsening of OSA in some individuals. Report of case(s) An 83 year old male presented for snoring, witnessed apneas, and daytime somnolence. A split-night PSG was ordered for evaluation. During the diagnostic portion of the study, the patient exhibited moderate OSA with an apnea hypopnea index (AHI) of 27/hr. The titration portion of the study was initiated with an oronasal (full face) interface. Continuous positive airway pressure (CPAP) pressure was titrated from 5cm H2O to 15 cm H20 with worsening of obstructive events and a residual AHI of 21 to 40/hr. Bilevel positive airway pressure (BiPAP) was then initiated and titrated from 19/15 cm H2O to 21/17 cm H20 with a continued residual AHI of 40/hr. No central apneas were noted. Upon review, suspicion arose whether the oronasal mask exacerbated the patient’s OSA. A repeat titration PSG was conducted with a nasal mask. With this mask a pressure of 8cm H20 resulted in a residual AHI of 0/hr. The patient was prescribed APAP 6-10 cm H20 with a nasal mask which resulted in excellent compliance and a residual AHI of 3.6/hr. Conclusion This case report presents a patient with worsening OSA due to use of an oronasal interface. Prior studies have suggested that oronasal masks produce less retropalatal airway opening than nasal masks. There may also be an effect on anterior-posterior distance of the mandible in the setting of exhalation. When possible, oronasal masks should be avoided in lab or home titration studies as they may lead to worsening OSA leading to escalation of PAP pressures and/or adjustment in titration modality. Support (if any)