ARDS Exacerbated by Low to Moderate Air Pollution in Severe Trauma

The risk of developing acute respiratory distress syndrome (ARDS) is increased by long-term exposure to low to moderate air pollution in persons having experienced severe trauma, according to a study published in the American Journal of Respiratory and Critical Care Medicine.

This study included a prospective cohort of 996 individuals who were critically ill, were older than 13 years, and had experienced acute trauma with an injury severity score >15. Isolated acute head injuries and mortalities were excluded. ARDS developed in 24% (n=243) of the individuals, with 6-week exposure to nitrogen dioxide, sulfur dioxide, and particulate matter <2.5 μm showing significant associations with ARDS (P <.05). Short-term exposures to nitrogen dioxide, carbon monoxide, and particulate matter <2.5 μm for 3 days before presentation did not show an association with ARDS; sulfur dioxide, however, was associated nonlinearly.

Exposure to ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and particulate matter <2.5 μm during a 3 year period demonstrated strong associations with ARDS (P <.01) after adjustments These associations persisted despite the fact that exposure levels were mostly lower than the  quality standards set by the United States and the European Union.

To determine the exposures to ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, and particulate matter <2.5 μm, the study researchers calculated weighted averages of daily readings from every monitor within a 50-km radius of the individuals. The possible development of ARDS was tracked for 6 days in accordance with Berlin Criteria. Multivariable logistic regression was used to evaluate the relationship between individual exposures and ARDS, with adjustments for possible confounders.

The researchers concluded that “[l]ong-term low to moderate-level air pollutant exposure is associated with a greater risk of developing ARDS after severe trauma, and represents a novel and potentially modifiable environmental risk factor for ARDS.”

Reference

Reilly JP, Zhao Z, Shashaty MGS, et al. Low to moderate air pollutant exposure and acute respiratory distress syndrome after severe trauma [published online August 1, 2018]. Am J Respir Crit Care Med. doi:10.1164/rccm.201803-0435OC