Excessive Daytime Sleepiness in Chronic Obstructive Pulmonary Disease: MATERIALS AND METHODS
Fourteen male patients with stable COPD were randomly selected from the Chest Medicine Clinic at the Veterans Administration Medical Center in Oklahoma City. Patients were selected without regard to the presence or absence of daytime sleepiness. The mean age was 60 years (range, 48 to 72 years). Patients were selected with a waking Pa02 of less than 70 mm Hg and less than 50 percent predicted FEV,. All patients were in stable condition receiving optimal therapeutic measures with no evidence of acute pulmonary disease or respiratory failure. None of the patients was receiving sedatives or psychotropic drugs at the time of the study. Clinically, none of these patients had complaints of significant daytime sleepiness.
Each patient underwent one standard all-night polysomnography evaluation followed by MSLT. The polysomnogram included standard C3 and occipital electroencephalogram (EEG), electro-oculo- gram (EOG), submental electromyogram (EMG), and electrocardiogram (ECG). Nasal and oral air flow were monitored via expired C02 and respiratory effort was assessed with an esophageal balloon. Leg movements were monitored by anterior tibialis EMG to detect myoclonus. Oxygen saturation was monitored via ear oximetry.
All nocturnal polysomnograms were scored for sleep studies in accordance with standard criteria. On the day following the all- night polysomnogram, each patient underwent MSLT. This was accomplished by having each patient take a nap four times throughout the day at two-hour intervals beginning at 8:30 am. Each nap was monitored by recording the EEG, EOG, and EMG to assess the sleep onset latency and the presence of sleep onset REM periods. buy antibiotics canada
The Pearson product moment correlation was used to assess the relationship between the MSLT results and the various respiratory parameters. Informed consent was obtained from all subjects and the study was approved by the Institutional Review Board of the University of Oklahoma Health Sciences Center.