P136 Non-invasive assessment of diaphragm contractility using surface mechanomyography in healthy subjects. (15th November 2017)

• Record Type: Journal Article
• Authors: Lozano-García, M; Sarlabous, L; Moxham, J; Rafferty, GF; Jané, R; Jolley, CJ
• Is Part Of: Thorax. Volume 72(2017)Supplement 3
• Page Start: A156
• Page End: A157
• Publication Date: 2017-11-15
• Subjects: Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thoraxjnl-2017-210983.278
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : Introduction: The current gold standard assessment of diaphragm contractility involves invasive measures of transdiaphragmatic pressure (Pdi) (ATS/ERS 2002). Surface mechanomyography (sMMG) is a non-invasive measure of muscle fibre vibration during contraction. Sarlabous et al (ERJ 2015) reported a high correlation between diaphragm sMMG (sMMGdi) amplitude and inspiratory mouth pressure, a measure of global respiratory muscle function. To further validate the technique, the relationship between sMMGdi and Pdi was examined in this study, hypothesising that there would be a close relationship between sMMGdi and Pdi in healthy subjects. Methods: Pdi and sMMGdi (right lateral chest) were measured in 12 healthy subjects (6 male, age 33 (30–38) years, BMI 22.2 (20.6–24.2) kg/m2) during an increasing inspiratory threshold loading protocol. sMMGdi signals were analysed using fixed sample entropy (fSampEn). Mean and peak values, and the area under the curve of inspiratory Pdi and fSampEn sMMGdi, were calculated and compared. Results: Strong correlations between the non-invasive sMMGdi and the invasive Pdi measures were observed for all three parameters (figure 1 ). Conclusion: The strong correlation between measures of sMMGdi and Pdi in healthy subjects suggests that sMMGdi could provide a clinically applicable noninvasive index of respiratory muscle contractility in patients with respiratory muscle weakness for diagnosis and monitoring.