Correlation Between Muscle Strength and Thickness in Critically Ill Patients

"The thickness of the diaphragm and quadriceps will be assessed using bedside ultrasound, utilizing a 13-6 MHz cm linear probe. The measurement of the right hemidiaphragm's end-expiratory thickness will be conducted via diaphragm ultrasound. For accurate positioning, the ultrasound probe will be placed along the right anterior axillary line, specifically between the ninth and tenth intercostal spaces, in a sagittal oblique orientation. To enhance measurement consistency, the probe's position on the skin will be marked.~To ascertain accuracy, the operator will conduct each measurement three times, and the mean of these three values will be used for analysis. Similarly, for diaphragmatic assessment and peripheral assessments (Qthick and CSA) of the lower limbs, the examination areas will be demarcated on the skin with a dermatographic pen, ensuring measurement reproducibility over different timepoints."

"The assessment of limb muscle strength in this study will be conducted using the Medical Research Council (MRC) Score. For a more precise evaluation of quadriceps strength, a dynamometer will be employed.~Furthermore, the study will incorporate an invasive method for gauging inspiratory muscle strength, utilizing the negative inspiratory force (NIF) metric. Post-extubation, the maximum inspiratory pressure (MIP) will be determined using an electronic manometer. Three separate MIP measurements will be executed, and the highest reading among these will be recorded as the definitive measurement."