title: Influence of thoracoabdominal pattern of breathing on respiratory resistance.
abstract: The purpose of this study was to test the hypothesis that voluntary changes in thoracoabdominal pattern of breathing may increase total respiratory resistance. Thirty-one normal subjects were asked to control their thoracoabdominal pattern of breathing by using a visual feedback. Thoracic and abdominal volume changes were measured by inductance plethysmography. Respiratory resistance and elastance were measured by forced oscillometry. The mean (+/-SD) percent thoracic contributions to tidal volume during thoracic or abdominal breathing were 75 (+/-11) and 25% (+/-9), respectively. These changes induced small but significant increases in resistance (P < 0.005) and elastance (P < 0.002). The increased resistance was observed in 22 subjects for thoracic breathing (P < 0.016) and in 21 subjects for abdominal breathing (P < 0.043). The mean value (+/-SD) of individual increases in resistance during thoracic or abdominal breathing, compared with normal breathing, were 9.2 +/- 17.5 and 9.4 +/- 19.9%, respectively. The fact that departing from spontaneous pattern increases respiratory resistance is consistent with the notion that breathing pattern is optimally adjusted on the basis of mechanical criteria.
authors.affiliation: Laboratoire de Neurologie et Physiologie du Développement, Hôpital Robert-Debré, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Gallego
authors.forename: S
authors.initials: S
authors.lastname: Benammou
authors.forename: G
authors.initials: G
authors.lastname: Vardon
authors.forename: B
authors.initials: B
authors.lastname: Chambille
authors.forename: A
authors.initials: A
authors.lastname: Denjean
authors.forename: H
authors.initials: H
authors.lastname: Lorino
mesh_terms: D000005:Abdomen / Q000502:physiology*; D000328:Adult; D000403:Airway Resistance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D012119:Respiration / Q000502:physiology*; D013909:Thorax / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology*