Loop gain measured from polysomnography can be influenced by respiratory event scoring in obstructive sleep apnea (OSA), according to new research published in the Annals of the American Thoracic Society.

Methods for quantifying loop gain in OSA using polysomnography have been developed that predict favorable responses to upper airway surgery; however, these methods are dependent on respiratory event scoring and may be affected by hypopnea scoring criteria.

Thus, researchers conducted a retrospective analysis of 46 polysomnographys performed before and after upper airway surgery to determine to what extent differences in hypopnea scoring affect loop gain measurement.