Does zolpidem enhance the yield of polysomnography?

STUDY OBJECTIVES

An uncomfortable environment or continuous positive airway pressure (CPAP) intolerance may cause poor sleep efficiency during polysomnography and result in a poor-quality study. Unsatisfactory polysomnograms often must be repeated. Nonbenzodiazepine hypnotics may improve sleep efficiency without disruption of sleep architecture. We hypothesized that premedication with zolpidem improves polysomnogram quality and decreases the need to restudy.

METHODS

We retrospectively reviewed 200 consecutive polysomnograms. Zolpidem premedication was not standardized and was prescribed at the discretion of consulting sleep physicians, who were unaware of this study. We compared the quality of polysomnograms between patients who received zolpidem 10 mg prior to polysomnography and those who did not. A poor-quality polysomnogram was defined as having insufficient sleep time to allow for diagnosis, incomplete CPAP titration with a resulting apnea-hypopnea index > 10 on the highest level of CPAP achieved, or complete CPAP intolerance.

RESULTS

Of 200 records reviewed, 54 patients (27%) received zolpidem. Demographics did not differ between groups. Premedication with zolpidem resulted in improved sleep latency (11.8 +/- 9.5 minutes vs 26.0 +/- 19.9 minutes, p = .002) and sleep efficiency (89.5% +/- 5.6% vs 78.8 +/- 12.3, p < .0001). Zolpidem premedication resulted in significantly fewer studies meeting criteria for poor quality (7.4% vs 33.6%, p = .005). Of the 49 studies meeting criteria for poor quality, 21 were repeated using zolpidem, showing significant improvements in sleep latency (10.8 +/- 7.1 minutes vs 42.8 +/- 30.5 minutes, p = .0004) and sleep efficiency (89.5% +/- 4.9% vs 61.8% +/- 13.7%, p < .0001). No study repeated with zolpidem met criteria for poor quality.

CONCLUSIONS

Pretreatment with zolpidem significantly improved polysomnographic quality and may decrease the need to repeat polysomnograms.