Long-Term Adherence to Positive Airway Pressure Therapy in Saudi Ambulatory Patients with Obesity Hypoventilation Syndrome and Severe Obstructive Sleep Apnea: A One-Year Follow-Up Prospective Observational Study

Sleep time on back as a predictor of adherence to positive airway pressure therapy

Upper airway collapse can be effectively dealt with positive airway pressure (PAP), and patient adherence is considered as a major determining factor for success of PAP therapy. This study was performed to determine the potential factors affecting the adherence to PAP in patients with OSA by using polysomnography (PSG) parameters recorded for diagnosis of OSA. The data of 158 patients between December 2018 and July 2021 were collected. They were prescribed with PAP and used the device during the adaptation period for 90 days. They were categorized into adherent and non-adherent group according to the criteria of good adherence as use of PAP ≥ 4 h per night on 70% of nights. Demographic, clinical characteristics, and PSG results were reviewed. Among 158 patients engaged in PAP therapy, 121 patients (76.6%) met the criteria of good adherence. No significant differences were found in good adherence rate regarding demographic and clinical characteristics. None of the polysomnographic factors showed significant differences between adherent and non-adherent groups. However, the percentage of sleep time on back in the adherent group was significantly higher than non-adherent group (p = 0.041). The cut-off value was determined to be 41.45% (95% confidence interval 0.43 to 0.79) by receiver operating characteristic curve analysis and the odds ratio was calculated as 2.97. Only the percentage of sleep time on back appeared to be polysomnographic predictor for identifying good adherence to PAP therapy in OSA patients. However, the conclusions may be limited in generalization due to the small sample size.

Results of CPAP Titration and Short-Term Adherence Rates in Patients with Obesity Hypoventilation Syndrome and Mild/Moderate Obstructive Sleep Apnea

PURPOSE

No study has assessed the titration success of CPAP therapy in patients with obesity hypoventilation syndrome (OHS) and an apnea-hypopnea index (AHI) <30 event/h. This study aimed to assess the titration success of CPAP therapy under polysomnography and subsequent short-term adherence (1 month) in patients with OHS and an AHI <30 event/h.

METHODS

Consecutive OHS patients with an AHI <30 events/h between 2010 and 2019 were included (n=54). All OHS patients were first started on CPAP during the therapeutic sleep-study. If the therapeutic-study showed that the SpO2 remained < 90% for 20% of the total sleep time, a second therapeutic study was arranged with bi-level PAP (BPAP). Thirty patients agreed to participate in the 1-month follow-up adherence study. We applied the American-Thoracic-Society criteria for PAP adherence.

RESULTS

The mean age was 54.8±14.6 years, and the mean BMI was 45.9±12.2 kg/m². Successful titration on CPAP was attained in 36 (66.7%) patients, and 18 (33.3%) required BPAP. Patients who failed the CPAP trial had a significantly higher PaCO2 and bicarbonate, a more restrictive respiratory pattern on spirometry, and a significantly higher time with SpO2<90% (mins) during sleep. The only independent correlate of CPAP-titration success on the multivariable regression analysis was the desaturation index (OR: 1.33 [1.033-1.712]). More than 80% of the participants were using CPAP therapy after one-month with no differences in adherence between the CPAP and BPAP groups.

CONCLUSIONS

The current results suggest that CPAP therapy could be an acceptable alternative therapy to BPAP in patients with OHS without severe OSA.