Clinical Application of the Effect of Respiratory Muscles Electrical Stimulation on Weaning in Patients With Difficult Weaning of the Mechanical Ventilation

Change in Diaphragm Excursion (DE) Measured by M-mode Ultrasound from Baseline to Day 28 (cm)

Diaphragm excursion will be measured by M-mode ultrasonography on the right hemidiaphragm. A 3.5-5.0 MHz convex probe is placed in the right subcostal region between the mid-clavicular and anterior axillary lines. The excursion (cm) during spontaneous breathe will be recorded as the average of three consecutive breaths. The outcome is the change in excursion from baseline to Day 28.

Time frame: Baseline (within 24 hours before randomization) and Day 28 after randomization

Change in Diaphragm Thickening Fraction (TFdi) from Baseline to Day 28 (%)

Diaphragm thickness will be measured in the zone of apposition of the right hemidiaphragm with a high-frequency linear probe in B-mode. Thickness at end-expiration and end-inspiration will be recorded as the average of three breaths. The diaphragm thickening fraction (TFdi, %) is calculated as: (Thickness at end-inspiration - Thickness at end-expiration) / Thickness at end-expiration × 100. The outcome is the change in TFdi from baseline to Day 28.

Time frame: Baseline to Day 28

Change in Diaphragm Thickness (DT) Measured by B-mode Ultrasound from Baseline to Day 28 (mm)

Diaphragm thickness (mm) will be measured in the zone of apposition of the right hemidiaphragm using a high-frequency linear probe (7-12 MHz) in B-mode at end-expiration. The value is the average of three consecutive breaths. The outcome is the change in diaphragm thickness from baseline to Day 28.

Time frame: Baseline to Day 28

Weaning Success From Invasive Mechanical Ventilation Within 28 Days (% of Participants)