S134 What are the long term outcomes for patients using non-invasive ventilation (NIV) for continuous positive airway pressure (CPAP) failure?

Introduction Current evidence is inconclusive in recommending mode of positive airways pressure (PAP) for the treatment of obesity related respiratory failure (ORRF). We wished to understand the phenotype of patients failing Continuous Positive Airway Pressure (CPAP) and to evaluate whether treatment escalation improved patient outcomes. CPAP Failure was defined as; a high remnant Apnoea Hypopnoea Index (AHI) despite CPAP, persistent hypercapnia or hospital admission with type 2 respiratory failure (T2RF). Aim To assess whether Non-invasive Ventilation (NIV) improves Apnoea Hyponoea index (AHI), PaCO2, compliance and somnolence at one year in patients who have failed CPAP therapy. Methods We retrospectively identified 91 patients between July 2011 and August 2019 in whom CPAP had failed and been exchanged for NIV. 36 patients had baseline data available at the time of their switch to NIV. We explored patient records to identify phenotype of sleep disordered breathing, reason for exchange to NIV, capillary blood gas, compliance and Epworth Sleepiness Score (ESS) at exchange and 12 months. Results Data were obtained for 36 patients, mean (SD) age 63.5 (12.5) years, BMI kg/m239.24 (10.76). Sleep study at diagnosis showed AHI 38.31 (32.43), SpO285.93 (4.82)%, total sleep time SpO2 Conclusion Switching from CPAP to NIV in this cohort resulted in significant improvement in compliance and PaCO2 with other variables demonstrating trends towards improvement. This highlights the importance of reassessment and revising appropriate PAP treatment plans according to patient phenotype in order to improve patient outcomes. The high rate of hospital admissions suggests patients require ongoing monitoring of PAP therapy.