Diaphragm dysfunction contributes to prolonged mechanical ventilation (PMV) and difficult weaning. Inspiratory muscle training (IMT) may improve respiratory muscle performance, while serial diaphragm ultrasound offers a bedside method for monitoring diaphragmatic recovery. This study used diaphragm ultrasound to evaluate the effects of high- versus low-intensity IMT in patients with PMV and diaphragm dysfunction.
In this prospective study, patients received high- or low-intensity IMT for up to 2 weeks or until ventilator liberation. Respiratory mechanics, including respiratory rate, tidal volume, minute ventilation, rapid shallow breathing index, and maximal inspiratory pressure, were assessed twice weekly. Diaphragm excursion and thickening fraction were also measured serially after IMT initiation. Changes in respiratory physiological parameters and diaphragm ultrasound measurements were compared between the two IMT groups, and differences in ventilator liberation outcomes were evaluated.