Last Updated: 2009-03-27 16:37:21 -0400 (Reuters Health)

In patients with obstructive sleep apnea, a one-time dose of a nonbenzodiazepine sedative during polysomnography may improve short-term compliance with continuous positive airway pressure (CPAP) therapy, researchers have observed.

"Short-term compliance may correlate with long-term compliance and interventions aimed at the initial treatment period would potentially offer the greatest benefit in adaptation to CPAP with subsequent improvements in future use," they note in the March issue of Chest.

Poor compliance and initial intolerance to CPAP limit the therapy’s effectiveness, Dr. Jacob Collen of Walter Reed Army Medical Center, Washington, D.C., and colleagues point out, and factors that reliably predict CPAP tolerance and use are largely unknown.

To investigate, they retrospectively analyzed CPAP compliance after the first 4 to 6 weeks of treatment in 400 consecutive patients. The mean age of study subjects was 47 years, and 78% were men.

"Good" CPAP compliance was defined by the researchers as the use of CPAP for more than 4 hours per night on more than 70% of nights.

Subjects with good compliance tended to be slightly older (48.2 years vs 45.8 years; p=0.02), the researchers found, with patients older than age 50 roughly twice as likely as those younger than 50 to have good compliance (odds ratio, 1.94; p=0.003).

Patients with good compliance were also significantly more likely to have received a sedative/hypnotic at the time of their CPAP titration (77.0% vs 57.6%; p < 0.0005). In addition, patients who received a sedative or hypnotic during titration used CPAP on more days and for longer periods than those who did not receive such assistance. They also had longer sleep times, greater sleep efficiency during polysomnography and improved CPAP titrations, as evidenced by lower respiratory disturbance index on the final CPAP pressure, the researchers note.

No other measured variable was associated with greater CPAP use.

"It is important," the investigators conclude, "to better define how the use of sedative/hypnotics during polysomnography can improve short-term compliance (with CPAP) in a randomized clinical trial."

Chest 2009;135:704-709.