Patients often have difficulty sleeping during overnight sleep testing in a lab environment. The purpose of this study is to determine if taking a sleep aid will improve sleep and therefore the quality of the sleep study.

The increasing awareness of sleep-disordered breathing (i.e obstructive sleep apnea) has created a growing demand for polysomnography (sleep study), resulting in excessive waiting times in many laboratories. Sleep centers have therefore needed to develop methods to improve their efficiency. Unfortunately many patients find it difficult to fall asleep in the unfamiliar environment of a laboratory setting (the "first-night effect"), circumstances that may prolong falling alseep and staying sleep. Likewise, intolerance of continuous positive airway pressure (CPAP) may also reduce the quality of the sleep study. Poor quality studies may lead to an inability to make a diagnosis or adequately titrate CPAP therapy. Unsatisfactory studies may need to be repeated.

Sleep aids (hypnotics) are commonly used to treat both acute and chronic insomnia. These agents have minimal side-effects and do not disrupt normal sleep architecture or alter respiratory events. These attributes make such agents ideal for use to improve the quality of sleep studies and enhance the efficiency of sleep centers.

In a recent retrospective review, we found that the use of a hypnotic prior to the sleep study resulted improved patient satisfaction and improved quality of the sleep study with significantly less studies needing to be repeated. Although promising, these results must be validated with a prospective, randomized, placebo-controlled trial.

Eszopiclone (Lunesta) is a new non-narcotic, non-benzodiazepine hypnotic agent which received FDA approval on December 15, 2004 for the treatment of acute and chronic insomnia. Multiple clinical trials have found that eszopiclone decreases sleep latency, improves sleep efficiency/maintenance and reduces wake time after sleep onset (WASO). Given its efficacy in promoting sleep onset and sleep maintenance and its excellent safety profile, this agent should be ideal as a pre-study sedative. The purpose of this study is to validate the use of Lunesta in improving the quality of overnight sleep studies.

Inclusion Criteria:

• All adult patients aged 18-65, evaluated by a sleep medicine provider in the Walter Reed Army Medical Center Sleep Disorders Clinic, who are referred for PSG for suspected Obstructive Sleep Apnea Syndrome

Exclusion Criteria:

• Pregnancy
• Liver dysfunction or history of EtOH abuse
• Concomitant use of benzodiazepines, narcotics or ketozonazole
• Decompensated CHF
• CVA within 3 months
• Uncontrolled psychiatric disorders
• Patients < 18 years old
• Patients over 65