Airway mucus plugs and ventilatory support during exacerbations, with subsequent outcomes, in patients with chronic obstructive pulmonary disease or emphysema.

BACKGROUND

Airway mucus plugs are associated with airflow obstruction and exacerbations in stable chronic obstructive pulmonary disease (COPD); however, their roles during exacerbations remain unclear. This study aimed to examine whether mucus plugs during exacerbations are associated with ventilatory support requirements and prognosis in patients with COPD.

METHODS

This single-center retrospective study included patients with COPD, defined by airflow limitation on spirometry or emphysema on computed tomography (CT), who presented to the emergency department, and were diagnosed with COPD exacerbation. Mucus plugs during exacerbations were visually assessed on CT and analyzed in relation to the need for ventilatory support (primary outcome).

RESULTS

Of 86 patients with a median mucus plug score of 3.5 (interquartile range, 1-7), 26 (30.2%) received ventilatory support. In multivariable logistic regression analysis, a higher mucus plug score (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.16-1.59) and higher C-reactive protein level were significantly associated with the need for ventilatory support. In a Cox proportional hazards model, a higher mucus plug score (hazard ratio [HR], 1.17; 95% CI, 1.07-1.29) and long-term oxygen therapy use were significantly associated with a shorter time to re-exacerbation or all-cause death within 1 year. Mucus plugs significantly decreased from the exacerbation to the recovery phases in a sub-analysis of 20 patients who underwent CT in both phases.

CONCLUSION

A higher mucus plug score was associated with the need for ventilatory support and poorer clinical outcomes, suggesting that mucus plugs may impair ventilation and worsen the prognosis of COPD exacerbations.