Diaphragmatic ultrasonographic evaluation as an assessment guide for predicting noninvasive ventilation failure in acute exacerbation of chronic obstructive pulmonary disease.

Background: Dynamic hyperinflation in severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) leads to diaphragmatic fatigue and causes acute respiratory failure. Ultrasound is reliable for evaluating diaphragmatic function. In this study, we aimed to assess the ability of diaphragmatic ultrasound to predict noninvasive ventilation (NIV) failure.

Methods: This prospective single-center observational cohort study was performed on patients with AECOPD who required NIV in the emergency department between October 1, 2020, and September 30, 2022, at a tertiary healthcare center. The diaphragmatic ultrasound was measured using diaphragmatic excursion (DE) before applying NIV and diaphragmatic thickening fraction (DTF) during NIV use for 2 h. The area under the receiver-operating characteristic (AUROC) curves analysis and multivariable logistic regression was performed to assess the ability of diaphragmatic ultrasound to predict NIV failure in 48 h.

Results: 111 patients were included in this study. DTF was an independent variable associated with NIV failure, with an adjusted odds ratio of 0.91 (95 % confidence interval [CI] 0.85-0.98), with a p-value of 0.009. DE and DTF had AUROC of 0.905 (95 % CI 0.835-0.975) and 0.940 (95 % CI 0.894-0.986), respectively, to predict NIV failure within 48 h. The lower DE and DTF increased the probability of NIV failure. The cutoff value of the DTF was 20 %, with a sensitivity of 92.0 % (95 % CI 74.0 % - 99.0 %) and a specificity of 93.0 % (95 % CI 85.4 % - 97.4 %) and the cutoff of the DE was 1.2 cm, with a sensitivity of 88.0 % (95 % CI 68.8 % - 97.5 %) and a specificity of 84.9 % (95 % CI 75.5 % - 91.7 %).

Conclusions: Diaphragmatic ultrasound, especially DTF at 2 h during NIV use, is a validated tool for predicting NIV failure in patients with AECOPD. Early detection of diaphragmatic dysfunction with diaphragmatic ultrasound in AECOPD with NIV could help identify high-risk patients and guide clinical decisions. However, further benefits from its implementation in management are required.