Ultrasound examination in assessing the functional state of the diaphragm in patients with respiratory failure requiring respiratory support

Abstract

Diaphragm dysfunction (DD) is diagnosed in 60% patients 24 hours after intubation. Diaphragm ultrasound (DU) facilitates non-invasive assessment of excursion and thickness of the diaphragm throughout the breathing cycle. Sonographically measured excursion and thickening fraction (TF) of the diaphragm show moderate correlation with reference methods for diaphragm dysfunction detection. Both increase and decrease in diaphragm thickness in mechanically ventilated patients are associated with prolonged mechanical ventilation. TF exceeding 25% increases probability of successful weaning. Maintaining TF within 15–40 % might shorten the duration of mechanical ventilation.