Ultrasound shear wave elastography for assessing diaphragm function within the intensive care unit

Availability of robust non-invasive tools for assessing diaphragm function is clinically relevant in a variety of clinical settings. Diaphragm shear modulus (SMdi) assessed by using ultrasound (US) shear wave elastography (SWE) can be used as a surrogate of transdiaphragmatic pressure (Pdi) that is considered as the most specific approach to assess diaphragm function. Here, we investigated the ability of SWE to reveal changes in transdiaphragmatic pressure for assessing diaphragm function within an ICU setup. SWE was performed in 22 mechanically ventilated patients within varying breathing conditions to induce changes in Pdi. Eight patients displayed a significant correlation between changes in Pdi (ΔPdi) and changes in SMdi (ΔSMdi). An absence of correlation was associated with a significantly higher respiratory rate. These findings highlight the need to increase SWE sampling rate to improve the applicability of SWE for diaphragm monitoring.