A Method for Measuring Loop Gain and Its Clinical Significance in Patients with Obstructive Sleep Apnea

Abstract

The pathogenesis of obstructive sleep apnea (OSA) has been explained from both anatomic and non-anatomic perspectives. Previous studies have indicated that OSA is most closely associated with anatomic factors related to upper airway obstruction, but its association with non-anatomic factors for upper airway obstruction has been increasingly understood and valued. The non-anatomic parameters for evaluating therapeutic effect include pharyngeal critical closing pressure, arousal threshold, loop gain and dilator muscle dysfunction, namely PALM. Monitoring and analyzing the weight of these four factors in the pathogenesis of OSA may contribute to the guidance of individualized treatment. Loop gain is a method for measuring the gain or sensitivity of negative feedback loop of respiratory control system to estimate the ventilation volume obtained by increasing the driving force of respiration to some extent. Higher loop gain may lead to hypocapnia and inhibition of upper airway respiratory drive, thereby aggravating the severity of OSA. We detailed a method for measuring loop gain and its clinical significance in patients with OSA.

Keywords

• sleep apnea, obstructive|apnea|continuous positive airway pressure|loop gain