Marchioni A, et al. - In patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) with hypercapnic acidosis, the effect of ultrasound (US)-assessed diaphragmatic dysfunction (DD) on noninvasive ventilation (NIV) failure was determined in this single-center prospective study. Correlation with the transdiaphragmatic pressure, as assessed using the invasive sniff maneuver (Pdi sniff), was also studied. For identifying DD+/- status, change in diaphragm thickness (ΔTdi) < 20% during tidal volume was the predefined cutoff. Findings demonstrated the reliability of early and noninvasive US assessment of DD during severe AECOPD. Furthermore, this allowed accurate detection of patients at major risk for NIV failure and worse prognosis. ΔTdi was seen to be highly correlated with Pdi sniff.