Complex sleep apnea in patients with obstructive sleep apnea on opioids for chronic pain

Complex sleep apnea (CompSA) is defined as the development of central events during a continuous positive airway pressure (CPAP) titration in a patient with obstructive sleep apnea (OSA). We hypothesized that patients with OSA on chronic opioids would fail a CPAP titration more frequently than patients with OSA not on opioid therapy and that the increased failure rate would be due to a greater prevalence of CompSA. In a retrospective chart review, we identified 58 patients with OSA on opioids and compared them to 150 patients with OSA not on opioids. CPAP titration failure was defined as an apnea-hypopnea index greater than 5/h at all CPAP pressures tested. CompSA was defined as the development of a central apnea index greater than 5/h during the CPAP titration study. Nineteen of the 58 patients (32.8%) with chronic opioid use and 18 of the 150 (12.0%) in the control group had CPAP titration failure (P-value 0.001). Six of the 49 patients (12.2%) with pure OSA in the opioid group and 5 of the 146 (3.4%) with pure OSA in the control group developed CompSA (odds ratio: 3.93; 95% confidence interval: 1.14–13.52; P-value: 0.03). Logistic regression showed that opiate use still predicted the presence of CompSA after coronary artery disease, hyperlipidemia, antidepressant usage and benzodiazepine use were accounted for. Patients on chronic opioid therapy had a higher percentage of treatment failure, and this was secondary to a higher prevalence of CompSA and persistence of central events seen on the diagnostic sleep study.