title: Controlled twitch mouth pressure reliably predicts twitch esophageal pressure.
abstract: The present study hypothesized that twitch mouth pressure (TwPmo) can reliably predict intrathoracic pressure swings reflected by twitch esophageal pressure (TwPes) using a controlled and automated trigger technique. TwPmo, TwPes, and transdiaphragmatic pressure (TwPdi) following bilateral anterior magnetic phrenic nerve stimulation were measured in 21 healthy subjects using an inspiratory pressure trigger (0.5kPa, experiment 1), an expiratory pressure trigger (0.5kPa, experiment 2), an inspiratory flow trigger (40ml/s, experiment 3), and no trigger at relaxed functional residual capacity (experiment 4). TwPmo and TwPes were correlated as follows: r=0.99, p<0.0001 (experiment 1); r=0.67, p=0.001 (experiment 2); r=0.96, p<0.0001 (experiment 3); no correlation (experiment 4). Bland and Altman analysis revealed most narrow limits of agreement for TwPmo and TwPes in experiment 1: bias (range) 0.15kPa (-0.03 to 0.32). TwPmo is an excellent predictor for TwPes when using a fully automated and controlled inspiratory pressure trigger. Thus, measurement of TwPmo could become a standard means assessing inspiratory muscle strength.
authors.affiliation: Department of Pneumology, University Hospital Freiburg, Killianstrasse 5, D-79106 Freiburg, Germany.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Kabitz
authors.forename: David
authors.initials: D
authors.lastname: Walker
authors.forename: Stephan
authors.initials: S
authors.lastname: Walterspacher
authors.forename: Wolfram
authors.initials: W
authors.lastname: Windisch
mesh_terms: D000328:Adult; D003964:Diaphragm / Q000502:physiology; D004558:Electric Stimulation; D004947:Esophagus / Q000502:physiology*; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D016014:Linear Models; D008176:Lung Volume Measurements; D008297:Male; D009055:Mouth / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology; D011237:Predictive Value of Tests; D011312:Pressure; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000502:physiology; D012132:Respiratory Muscles / Q000502:physiology*; D013270:Stomach / Q000502:physiology; D014797:Vital Capacity / Q000502:physiology