title: Esophageal and mouth pressure during sniffs with and without nasal occlusion.
abstract: The sniff maneuver has recently been advocated for assessing inspiratory muscle strength. We characterized the relationship between mouth pressure (Pmo) and esophageal pressure (Pes) during sniffs performed with open, semi-occluded, and occluded nose. In seven normal subjects, pressure was simultaneously measured with a mouthpiece (Pmo) an esophageal balloon (Pes) during high- and low-intensity sniffs performed from FRC. With open nose, the mean ratio Pmo/Pes was 0.96 +/- 0.05 (mean +/- SE). The mean ratio Pmo/Pes was not significantly different in high- and low-intensity sniffs. With one nostril occluded, the mean ratio Pmo/Pes was 1.03 +/- 0.04. The ratio Pmo/Pes was significantly higher than with open nose for all sniffs (P less than 0.05) and low-intensity sniffs (P less than 0.01). With both nostrils occluded, the mean ratio Pmo/Pes was 1.06 +/- 0.03, with occasional marked overestimation of Pes by Pmo. We conclude that Pmo generally reflects Pes during sniffs performed with open and semi-occluded nose, but not with complete nasal occlusion.
authors.affiliation: Département de médecine interne, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Héritier
authors.forename: C
authors.initials: C
authors.lastname: Perret
authors.forename: J W
authors.initials: JW
authors.lastname: Fitting
mesh_terms: D000328:Adult; D004947:Esophagus / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009055:Mouth / Q000502:physiology; D009666:Nose / Q000502:physiology; D011312:Pressure; D015656:Respiratory Mechanics / Q000502:physiology*; D012132:Respiratory Muscles / Q000502:physiology*