The efficacy of split-night sleep studies.

Positive airway pressure (PAP) therapy is the most commonly used medical modality to reverse the apneas, hypopneas and inspiratory flow-limited breaths which result in the oxyhemoglobin desaturation, altered sleep architecture, and daytime sleepiness representing the cardinal features of obstructive sleep apnea/hypopnea (OSA/H). Identifying optimal strategies to develop the initial positive airway prescription is of paramount importance to clinicians who evaluate patients with suspected OSA/H. In addition, with the growing appreciation of the clinical and physiologic importance of sleep-disordered breathing, there have been increasing demands on clinical resources to diagnose and treat these patients. The time, hardware, and personnel-intensive nature of in-laboratory polysomnography (PSG) are significant in light of the traditional paradigm that utilizes a full night PSG for a diagnostic evaluation and when indicated, another full night for PAP titration. Efforts to identify time and resource-conserving alternatives to this paradigm have focused on in-laboratory split-night studies, in which the diagnosis of OSA/H can be made, and a positive pressure prescription defined during a single overnight PSG. Case-control studies indicate that, when certain guidelines are applied, split-night PSGs result in prescription efficacy and patient adherence, which are comparable to the traditional two-night strategy. However, prospective, randomized trials designed with adequate power are required to further define the impact of a split-night strategy on clinical outcome. As more information becomes available regarding the factors that determine long-term adherence to positive pressure therapy, the potential for efficient, expeditious treatment, and cost savings with split-night sleep studies will likely receive greater attention.