Investigation of PM2.5 pollution during COVID-19 pandemic in Guangzhou, China.

The COVID-19 pandemic has raised awareness about various environmental issues, including PM2.5 pollution. Here, PM2.5 pollution during the COVID-19 lockdown was traced and analyzed to clarify the sources and factors influencing PM2.5 in Guangzhou, with an emphasis on heavy pollution. The lockdown led to large reductions in industrial and traffic emissions, which significantly reduced PM2.5 concentrations in Guangzhou. Interestingly, the trend of PM2.5 concentrations was not consistent with traffic and industrial emissions, as minimum concentrations were observed in the fourth period (3/01-3/31, 22.45 µg/m3) of the lockdown. However, the concentrations of other gaseous pollutants, e.g., SO2, NO2 and CO, were correlated with industrial and traffic emissions, and the lowest values were noticed in the second period (1/24-2/03) of the lockdown. Meteorological correlation analysis revealed that the decreased PM2.5 concentrations during COVID-19 can be mainly attributed to decreased industrial and traffic emissions rather than meteorological conditions. When meteorological factors were included in the PM2.5 composition and backward trajectory analyses, we found that long-distance transportation and secondary pollution offset the reduction of primary emissions in the second and third stages of the pandemic. Notably, industrial PM2.5 emissions from western, southern and southeastern Guangzhou play an important role in the formation of heavy pollution events. Our results not only verify the importance of controlling traffic and industrial emissions, but also provide targets for further improvements in PM2.5 pollution.

Extracorporeal membrane oxygenation for coronavirus disease 2019-associated acute respiratory distress syndrome: Report of two cases and review of the literature.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2, is a worldwide pandemic. Some COVID-19 patients develop severe acute respiratory distress syndrome and progress to respiratory failure. In such cases, extracorporeal membrane oxygenation (ECMO) treatment is a necessary life-saving procedure. CASE SUMMARY: Two special COVID-19 cases-one full-term pregnant woman and one elderly (72-year-old) man-were treated by veno-venous (VV)-ECMO in the Second People's Hospital of Zhongshan, Zhongshan City, Guangdong Province, China. Both patients had developed refractory hypoxemia shortly after hospital admission, despite conventional support, and were therefore managed by VV-ECMO. Although both experienced multiple ECMO-related complications on top of the COVID-19 disease, their conditions improved gradually. Both patients were weaned successfully from the ECMO therapy. At the time of writing of this report, the woman has recovered completely and been discharged from hospital to home; the man remains on mechanical ventilation, due to respiratory muscle weakness and suspected lung fibrosis. As ECMO itself is associated with various complications, it is very important to understand and treat these complications to achieve optimal outcome. CONCLUSION: VV-ECMO can provide sufficient gas exchange for COVID-19 patients with acute respiratory distress syndrome. However, it is crucial to understand and treat ECMO-related complications.

Clinical characteristics of acute respiratory syndrome with SARS-CoV-2 infection in children in South China.

BACKGROUND: A retrospective study was conducted to summarize the clinical information of childhood infections during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic. METHODS: Children with SARS-CoV-2 infection in 11 hospitals from three provinces of South China were included in the study. Clinical information was collected and compared with children and adults infected by SARS-CoV-2 in Wuhan. RESULTS: In total, 52 children were enrolled, including 28 boys. The median age was 9 years (interquartile range [IQR], 4-12); 44.2% cases were of clustered occurrences, 40.4% patients had fever, 48.1% had cough, and 46.2% had a high lymphocyte count. No abnormalities were found in the liver and kidney function. Also, 82.7% of patients received antiviral therapy, but such therapy did not shorten the time to virus negativity or hospital stay (P = .082). The time to virus negativity was 12.0 days (IQR, 8.0-16.8) and hospital stay was 14.5 days (IQR, 10.3-17.9). Compared with reports in Wuhan, there were more acute upper respiratory tract infection (AURTI) and fewer pneumonia cases (P = .000). Compared with the non-ICU adult COVID-19 in Wuhan, these children's diseases were relatively mild, with fewer complications. CONCLUSIONS: Children with SARS-CoV-2 infection had a mild fever, lymphocyte elevation was more common than reduction, and antiviral treatment had no obvious effect. The overall clinical manifestations were mild, and the prognosis was good.