Ultrasound shear wave elastography for assessing diaphragm function in mechanically ventilated patients: a breath-by-breath analysis
Open Access
- 27 November 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Critical Care
- Vol. 24 (1), 1-13
- https://doi.org/10.1186/s13054-020-03338-y
Abstract
Diaphragm dysfunction is highly prevalent in mechanically ventilated patients. Recent work showed that changes in diaphragm shear modulus (ΔSMdi) assessed using ultrasound shear wave elastography (SWE) are strongly related to changes in Pdi (ΔPdi) in healthy subjects. The aims of this study were to investigate the relationship between ΔSMdi and ΔPdi in mechanically ventilated patients, and whether ΔSMdi is responsive to change in respiratory load when varying the ventilator settings. A prospective, monocentric study was conducted in a 15-bed ICU. Patients were included if they met the readiness-to-wean criteria. Pdi was continuously monitored using a double-balloon feeding catheter orally introduced. The zone of apposition of the right hemidiaphragm was imaged using a linear transducer (SL10-2, Aixplorer, Supersonic Imagine, France). Ultrasound recordings were performed under various pressure support settings and during a spontaneous breathing trial (SBT). A breath-by-breath analysis was performed, allowing the direct comparison between ΔPdi and ΔSMdi. Pearson’s correlation coefficients (r) were used to investigate within-individual relationships between variables, and repeated measure correlations (R) were used for determining overall relationships between variables. Linear mixed models were used to compare breathing indices across the conditions of ventilation. Thirty patients were included and 930 respiratory cycles were analyzed. Twenty-five were considered for the analysis. A significant correlation was found between ΔPdi and ΔSMdi (R = 0.45, 95% CIs [0.35 0.54], p < 0.001). Individual correlation displays a significant correlation in 8 patients out of 25 (r = 0.55–0.86, all p < 0.05, versus r = − 0.43–0.52, all p > 0.06). Changing the condition of ventilation similarly affected ΔPdi and ΔSMdi. Patients in which ΔPdi–ΔSMdi correlation was non-significant had a faster respiratory rate as compared to that of patient with a significant ΔPdi–ΔSMdi relationship (median (Q1–Q3), 25 (18–33) vs. 21 (15–26) breaths.min−1, respectively). We demonstrate that ultrasound SWE may be a promising surrogate to Pdi in mechanically ventilated patients. Respiratory rate appears to negatively impact SMdi measurement. Technological developments are needed to generalize this method in tachypneic patients. NCT03832231.Keywords
Funding Information
- Fondation EDF
- Association Française contre les Myopathies
- Ile-de-France Regional Health Agency
This publication has 41 references indexed in Scilit:
- Ventilatory Failure, Ventilator Support, and Ventilator WeaningComprehensive Physiology, 2012
- Diaphragm dysfunction assessed by ultrasonography: Influence on weaning from mechanical ventilation*Critical Care Medicine, 2011
- Rapidly Progressive Diaphragmatic Weakness and Injury during Mechanical Ventilation in HumansAmerican Journal of Respiratory and Critical Care Medicine, 2011
- Increased duration of mechanical ventilation is associated with decreased diaphragmatic force: a prospective observational studyCritical Care, 2010
- Rapid Disuse Atrophy of Diaphragm Fibers in Mechanically Ventilated HumansThe New England Journal of Medicine, 2008
- Weaning from mechanical ventilationEuropean Respiratory Journal, 2007
- Human muscle hardness assessment during incremental isometric contraction using transient elastographyJournal of Biomechanics, 2005
- A Comparison of the General Linear Mixed Model and Repeated Measures ANOVA Using a Dataset with Multiple Missing Data PointsBiological Research For Nursing, 2004
- In vivo assessment of diaphragm contraction by ultrasound in normal subjects.Thorax, 1995
- Maximal Inspiratory Pressure Is Not a Reliable Test of Inspiratory Muscle Strength in Mechanically Ventilated PatientsAmerican Review of Respiratory Disease, 1990