We read with great interest the recent article by Her-mans et al. on diaphragmatic ultrasound, which provides a detailed guide on both methodology and clinical appli-cations [1]. This article has significantly enhanced our understanding of diaphragmatic ultrasound, especially for its application in intensive care unit (ICU) [2]. We would like to offer some additional considerations that could further enhance the use of this valuable technique. The authors point out that the right hemidiaphragm is generally more accessible and often used to represent overall diaphragmatic function, recommending bilateral measurements in cases of suspected hemiplegia or uni-lateral dysfunction. We agree with this approach. How-ever, we would like to address some challenges associated with visualizing the left hemidiaphragm, which is often less clear on ultrasound. Studies with healthy subjects have shown that while the left hemidiaphragm is gen-erally visible during quiet breathing, it becomes more challenging to capture during deep inspiration [3]. For optimal imaging of the left side, we suggest positioning the probe subcostally on the mid-clavicular line to best capture the dome of the left diaphragm. In ICU patients, however, visualization is often more challenging due to interference from gas in the lungs and gastrointestinal tract, which makes conventional views difficult (Fig.1A1, B2). In these cases, we find it helpful to visualize the dia-phragm adjacent to the spleen, using the spleen’s border along the mid-axillary line as a landmark. Additionally, we emphasize the value of the anatomic M-mode tech-nique, aligning the sampling line perpendicularly with diaphragmatic movement (Fig. 1A2, B2, A3, B3). This technique provides results comparable to conventional methods and proves particularly useful when standard imaging does not yield a clear view.
