Obstructive Sleep Apnea (OSA) is typically diagnosed on Polysomnography (PSG), however the access to PSG is limited. This prompts physicians to utilize other diagnostic methods and may lead to the prescription of Continuous Postive Airway Pressure (CPAP) therapy without PSG. The purpose of this study was to review: 1. efficacy and safety of empiric CPAP; 2. physicians’ diagnostic accuracy in cases of suspected OSA; 3. accuracy of empiric CPAP pressure as compared to the CPAP pressure established after a split-night PSG.
Retrospective chart review of patients who were prescribed empiric CPAP . Subjects’ characteristics (age, sex, BMI), Epworth Sleepiness Score before and after CPAP were obtained and compliance data were downloaded. CPAP pressures prescribed after PSG were compared with the empirically set pressures.
Eighty-nine patients (67 male; 52.2 +/− 11.7 years; BMI : 35.3 +/− 7.9; Epworth 13.8 +/− 5.7) were prescribed empiric CPAP (mean pressure of 9.5 +/−1.6 cm H2O). The average duration of CPAP therapy prior to PSG was 254 days. In 26 (29%) cases portable oximetry was used prior to CPAP prescription. Seventy-nine patients (89%) had OSA (mean AHI: 43.5 +/− 30.2 ). The optimal CPAP pressure, as determined on a split-night PSG, was 9.9 +/− 1.9 cm H2O and was not significantly different from the empiric CPAP pressure ( p = 0.12),however, 33 patients were undertreated (empiric CPAP pressure < optimal CPAP pressure).There was significant improvement in subjective somnolence in the entire group (ESS:13.8 +/− 5.7, after CPAP: 8.7 +/− 4.0, p <0.001). The mean CPAP compliance was 5.0 +/− 2.3 hrs/night (N= 67). There were no adverse effects from empiric CPAP therapy.CONCLUSIONS: 1. Pulmonologists can accurately predict presence of moderate and severe OSA, 2. Empiric CPAP therapy is safe and effective in improving hypersomnolence, 3. Mean CPAP compliance in this group is similar to compliance reported in other studies.
When access to PSG is limited, empiric CPAP can be safely prescribed and is effective.
R.P. Skomro, None.