SHORT REPORT Influence of gas density on simulated snoring

Influence of gas density on simulated snoring. G. Liistro, C. Veriter, D. Stanescu. #ERS Journals Ltd 1999. ABSTRACT: According to a recent theoretical model, snoring is related to instability of the upper airway (UA). Factors promoting UA instability include increased gas density. The aim of this study was to test the influence of gas density on simulated snoring production and supraglottic resistance. Supraglottic pressure and flow rate (V ') were measured in 10 healthy seated subjects during simulated snoring. Subjects breathed three different gas mixtures: Helium±oxygen, He 79%±O2 21% (He±O2); air; and sulphur hexafluoride±oxygen, F6S 79%±O2 21% (F6S±O2) administered in a random order. Supraglottic resistance (Rsg) was measured on its linear range during quiet breathing and V ' was measured at the onset and middle of snoring. Linear Rsg increased and V ' conversely decreased with gas density. These data are in agreement with predictions of a mathematical model of the upper airway showing that snoring occurs at lower flow rates when gas density is increased. Eur Respir J 1999; 13: 679±681. Pulmonary Laboratory and Division, Cliniques Universitaires St-Luc, B-1200 Brussels, Belgium.