Continuous positive airway pressure (CPAP) adherence rates and influencing factors following acute, traumatic tetraplegia

Background: Prevalence of obstructive sleep apnoea (OSA) following acute tetraplegia is up to 83%. CPAP is the first-line treatment however its effectiveness may be limited by poor adherence. Aim: To determine the rate and the factors associated with CPAP adherence in people with acute tetraplegia and OSA. Methods: Analysis of CPAP adherence in a multinational randomized controlled trial of 3 months of auto-titrating CPAP or usual care for OSA after acute tetraplegia. Participants were only randomised if they could tolerate CPAP for greater than 4 hours on 1 of 3 nights. Those in the CPAP treatment arm were “adherent” if they tolerated CPAP for >4 hours per night for 5-7 nights a week for at least 50% of the 13 week study. Univariate analyses were undertaken to determine associations between baseline factors and adherence. Results: 11 spinal cord injury centres participated in the study. 149 participants (134 men, age 46±34, 81±57 days post-injury) completed the study. 78% of participants with an Apnoea Hypopnoea Index (AHI) >10 passed the initial 3 night CPAP trial (164/211) and were randomized. Of the 79 study participants receiving CPAP, 23 (29%) were adherent. Assuming those who did not pass the initial trial would not have been adherent, overall CPAP adherence was 18% (23/126). Factors associated with CPAP adherence included higher AHI (p=0.01), higher abdominal girth (p=0.003) and study site (p=0.02). Conclusion: Adherence to CPAP following acute, traumatic quadriplegia is poor. Those with a higher AHI and abdominal girth are more likely to adhere. Clinician support and expertise with CPAP implementation is also likely to be important.