Is PM2.5 associated with emergency department visits for mechanical ventilation in acute exacerbation of chronic obstructive pulmonary disease?

Abstract

Patients with chronic obstructive pulmonary disease (COPD) can have recurrent exacerbations and acute respiratory failure (ARF) triggered by particulate matter with a diameter of ≤2.5μm (PM2.5). To prevent ventilator shortages, this study investigated the short-term association between PM2.5 concentration and emergency department visits (EDVs) among patients with acute exacerbation of COPD (AECOPD) requiring mechanical ventilation (MV). We conducted a time-series study to predict the PM2.5 concentration and number of ventilators needed. Daily counts of EDVs among AECOPD patients requiring ventilation from 2015 to 2019 were obtained from a hospital. Generalized linear models extending Poisson regression were used to explore the association of AECOPD with PM2.5 after controlling for the time trend, seasonal variations, and meteorological variables. Eight hundred seventy-five AECOPD patients receiving MV were recorded, of whom 734 received noninvasive ventilation and 141 received invasive ventilatory support. EDVs for AECOPD patients with ARF significantly increased by 3.5% (95% confidence interval [CI]: 2.51%-4.42%) per 10μgm-3 increase in PM2.5 concentration. Among seasons, PM2.5 concentration had the strongest effect on AECOPD patients with ARF in spring (<24.5°C), with a 1.64% (95% CI: -0.56% to 3.83%) increase in admissions per 10μgm-3 increase in same-day PM2.5 concentration. The interquartile range increase of 20μgm-3 between winter and spring was associated with an average EDV increase of 48.66%. This is the first study to predict the number of ventilators required by calculating quantitative estimates of the short-term effects of PM2.5 on EDVs for AECOPD patients with ARF. Adverse effects of PM2.5 on AECOPD patients requiring MV are evident, especially in the spring. Establishing protective standards and reducing the PM2.5 concentration to below various thresholds are urgently needed.