CPAP withdrawal usually leads to a rapid recurrence of OSA, a return of subjective sleepiness, and is associated with impaired endothelial function, increased urinary catecholamines, blood pressure, and heart rate. Thus the proposed study model appears to be suitable to evaluate physiological and therapeutic effects in OSA. Clinical trial registered with www.controlled-trials.com (ISRCTN93153804).

Background: The Epworth Sleepiness Scale (ESS) is a questionnaire widely used in English speaking countries for assessment of subjective daytime sleepiness. Objective: Our purpose was to translate and validate the ESS for use in German-speaking countries. Methods: A German translation of the ESS was administered to 159 healthy German-speaking Swiss and to 174 patients with various sleep disorders. Results: The mean ± SD of ESS scores in normals was 5.7 ± 3.0, in patients it was 13.0 ± 5.1 (p < 0.001). Scores were not correlated with age or gender but with the percentage of time spent at an oxygen saturation <90% (R = 0.35, p < 0.001), and the respiratory disturbance index (R = 0.26, p < 0.001) in primary snorers and sleep apnea patients. Item analysis confirmed internal consistency of the scale (Cronbach α = 0.60 in normals, and 0.83 in patients). Follow-up scores in 25 sleep apnea patients on treatment showed a reduction by 7 ± 5 points (p < 0.05). Conclusions: Our data validate the ESS for application in German-speaking populations. The simplicity, reliability and the apparent lack of relevant influences of language and cultural background on performance of the ESS makes it a valuable tool for clinical management and research.

Our purpose was to compare the effectiveness and side effects of a novel, single-piece mandibular advancement device (OSA-Monobloc) for sleep apnea therapy with those of a two-piece appliance with lateral Herbst attachments (OSA-Herbst) as used in previous studies. An OSA-Monobloc and an OSA-Herbst with equal protrusion were fitted in 24 obstructive sleep apnea patients unable to use continuous positive airway pressure (CPAP) therapy. After an adaptation period of 156 +/- 14 d (mean +/- SE), patients used the OSA-Monobloc, the OSA-Herbst, and no appliance in random order, using each appliance for 1 wk. Symptom scores were recorded and sleep studies were done at the end of each week. Several symptom scores were significantly improved with both appliances, but to a greater degree with the OSA-Monobloc. Epworth Sleepiness Scale scores were 8.8 +/- 0.7 with the OSA-Herbst, and 8.6 +/- 0.8 with the OSA-Monobloc devices, and 13.1 +/- 0.9 without therapy (p < 0.05 versus both appliances). The apnea/hypopnea index was 8.7 +/- 1.5/h with the OSA-Herbst and 7.9 +/- 1.6/h with the OSA-Monobloc device, and 22.6 +/- 3.1/h without therapy (p < 0.05 versus both appliances). Side effects were mild and of equal prevalence with both appliances. Fifteen patients preferred the OSA-Monobloc, eight patients had no preference, and one patient preferred the OSA-Herbst device (p < 0.008 versus OSA-Monobloc). We conclude that both the OSA-Herbst and the OSA-Monobloc are effective therapeutic devices for sleep apnea. The OSA-Monobloc relieved symptoms to a greater extent than the OSA-Herbst, and was preferred by the majority of patients on the basis of its simple application.