Preadmission exposure to air pollution and 90-day mortality in critically ill patients: A retrospective study.

OBJECTIVE We investigated the association between preadmission exposure to air pollutants and 90-day mortality in critically ill patients. METHODS This retrospective cohort study analyzed the medical records of adult patients (≥18 years) admitted to the intensive care unit of a tertiary academic hospital from 2015 to 2016. RESULTS Four air pollutants were not significantly associated with 90-day mortality and pulmonary disease-related 90-day mortality (P > 0.05). In patients with preadmission chronic obstructive lung disease (COPD), a 1 ppm increase in ozone (O3) and carbon monoxide (CO) was associated with a 1.04-fold and 5.99-fold increase in pulmonary disease-related 90-day mortality, respectively. CONCLUSIONS Preadmission exposure to air pollution was not associated with 90-day mortality in critically ill patients. However, a higher concentration of CO and O3 was associated with an increase in pulmonary disease-related 90-day mortality in patients with preadmission COPD.