Experience in using split-day studies for suspected obstructive sleep apnea syndrome

Background: Because in many locations the demand for sleep studies exceeds resources, we evaluated the utility of split-day in-laboratory studies (SDS) in highly selected patients. Methods: We studied 100 eligible cases: 68 mates (age 48.6 +/- 1.3 [standard error, SE] years, body mass index (BMI): 32.6 +/- 0.8 kg/m(2)) and 32 females (age 50.9 +/- 2.4 years, BMI: 36.3 +/- 1.3kg/m(2)) with severe subjective sleepiness (Epworth sleepiness scale: ESS >= 16) and suspected obstructive steep apnea syndrome (OSAS). Results: There were 86 conclusive studies that yielded both a diagnosis and sufficient information for management (86.0%) and 14 inconclusive studies that did not yield sufficient information for management (14.0%). In six cases (6.0%) with an inconclusive study a diagnosis was made, however, no titration data was obtained. Thus a definitive diagnosis was obtained in 92.0% of all cases. Those with inconclusive studies had additional assessment, and eight of them ultimately had a final diagnosis of a steep breathing disorder (SBD) and six had another steep disorder: four had narcolepsy, one had a movement disorder, one had steep deprivation. Thus there were six patients (6.0%) in whom SDS yielded only an SBD diagnosis but there was insufficient data for titration; two patients (2.0%) who ultimately had severe OSAS who were not diagnosed on SDS. Conclusions: SDS was found to be useful in the evaluation and treatment of highly selected patients with severe daytime sleepiness (ESS >= 16) and suspected OSAS. (c) 2005 Elsevier Ltd. All rights reserved.