Ultrasound-guided diaphragm evaluation and outcomes in severe acute exacerbation of chronic obstructive pulmonary disease (uDISCO Study): an observational study

Acute exacerbations of chronic obstructive pulmonary disease (COPD) are associated with compromised diaphragmatic function. This can be evaluated using point-of-care ultrasound. The association of diaphragm function with hospital length of stay or mortality has not been assessed earlier. This study aimed to evaluate the correlation of diaphragmatic function with length of hospital stay, mortality, and non-invasive ventilation (NIV) failure in severe acute exacerbation of COPD. Diaphragmatic excursion and thickening index (Tdi) were evaluated with ultrasound-guided assessment in individuals with severe acute exacerbation of COPD at the time of hospitalization. The individuals were evaluated for length of stay in survivors, NIV ventilation failure in those requiring NIV therapy, and mortality in non-survivors. A total of 110 individuals were screened, and 60 of these were enrolled. A total of 55 individuals survived, and 5 died. The length of stay had a negative correlation with excursion (R: -0.78, p<0.001) and Tdi (R: -0.96, p<0.001). The excursion and Tdi were smaller by 30% and 50%, respectively, in the event of NIV failure compared to NIV success. Excursion ≤1.96 cm [area under receiver-operating characteristic curve (AUROC): 0.958] or Tdi≤92% (AUROC: 0.974) were associated with length of stay ≥8 days. Excursion ≤1.48 cm (AUROC: 0.75) or Tdi≤51.2% (AUROC: 0.8) were associated with NIV failure. Tdi≤40% was associated with a high risk of mortality (RR: 22.67, p=0.035). Smaller diaphragmatic excursion, or Tdi, correlated with prolonged LoS, mortality, and NIV failure.