Discussion
asthma, VAP
RESPIRATORY DISEASE, ASTHMA
Relationships short-term pollutant exposure and mortality in hospitalized patients has been demonstrated previously, but effects on specific populations of patients are less well understood. With increasing appreciation of high-risk groups such as children, the current report is the first large scale study on the acute effects of PMCurrently, there are no research on the effect of ambient air pollution in heavily polluted regions on critical ICU patients such as those who have undergone major surgeries. Thus, our study is timely and will contribute significantly to the management of public health. Many studies on the effects of air pollutants on respiratory diseases are conducted in specific locations, and are therefore, subjected to the particular climate in that region and the susceptibility of the local population. Regional climates can influence the local air pollutant concentrations and composition. Jinan is an industrial city heavily focused on manufacturing and combined with the standard practice of burning coal in the winter put this city among the top 10 most polluted cities in China. PMThe ICU houses the most vulnerable patients in the most critical conditions; thus, it is often perceived as a protective shield against stressors and harmful environmental influences. However, the ability of ambient pollution to compromise the function of the ICU is underappreciated. Pre-admission air pollution exposure can aggravate the critical conditions of patients in the ICU. Groves et al. reported that pre-admission exposure to PMWhile LAF systems seem attractive in many aspects, more research is required in this area. Particulate matters are critical determinants of airborne bacterial concentration and community structure. While LAF systems are 89% more effective than displacement ventilation systems in reducing air contamination [Our results showed that the effects of air pollution on VAP incidence is acute, delayed by 2–3 days and cumulative. This is consistent with previous studies where a range of lag days have been demonstrated. In association with emergency department visits for asthma, PMThe current NAAQS in China for daily PMWe found that gender can significantly impact the association between PMOur study has four strengths. First, we simulated the interaction between PMHowever, several limitations are associated with this study. First, this study focused on the acute effect of air pollution on pediatric patients undergoing cardiac surgery in a single center, which limits the generalizability of the findings to other child populations and does not address the long-term effect of air pollution on VAP risk. We will try to implement a prospective multicenter or multi-PICU cohort study and provide higher level of evidence in the future clinical practice. Furthermore, the effects of long-term exposure to fine particulate matter on VAP are still unclear and thus the investigation of the long-term influence of PM