Exaggerated ventilatory drive estimates from epiglottic and esophageal pressure deflections in the presence of airway occlusion

Abstract

Esophageal and epiglottic pressure deflection measurements are widely used as gold-standard measures of ventilatory effort during sleep without consideration of differential obstruction effects between measurement sites. This study is the first to quantify the effect of airway occlusion on esophageal versus epiglottic pressure recordings during sleep. The findings of substantial acute effects of occlusion itself on esophageal and particularly epiglottic pressure deflections are important to consider in the planning, analysis, and interpretation of studies that rely on pressure deflections for inferences regarding inspiratory effort.

Neural ventilatory drive decline as a predominant mechanism of obstructive sleep apnoea events

“…(2) Drive—per intraoesophageal diaphragm EMG—is not measured clinically and rarely in physiology studies 8 19 25. Rather, in prior work, our laboratory and others have routinely measured oesophageal pressure swings as a marker of respiratory effort, which paint a very different picture of OSA pathogenesis3: while oesophageal pressures and diaphragm EMG signals track proportionally during unobstructed breathing,16 25 pressure swings become markedly augmented with sudden onset of obstruction36 and are diminished again at event termination with the release of pharyngeal obstruction. Mechanistically, occlusion and loss of tidal volume provides for an absence of (positive) volume-related chest wall recoil pressure, and diaphragm mechanical efficiency is increased via length tension and force velocity effects 25 27.…”