Characteristics and Outcomes of Patients with Pulmonary Acute Respiratory Distress Syndrome Infected with Influenza versus Other Respiratory Viruses

Yoo, Jung-Wan; Ju, Sunmi; Lee, Seung Jun; Cho, Min-Chul; Cho, Yu Ji; Jeong, Yi Yeong; Lee, Jong Deog; Kim, Ho Choel

The present study showed that approximately 46% patients with pulmonary ARDS had a concomitant respiratory viral infection and influenza A virus was most commonly isolated. Co-respiratory infection was more frequent in patients with influenza infection than in those with other respiratory viral infection. Although patients with influenza virus received more invasive treatment such as ECMO, clinical outcomes did not differ between patients with influenza infection and those Values are presented as number (%) or mean±SD. ICU: intensive care unit; MV: mechanical ventilation; LOS: length of stay; SD: standard deviation. with other viral infection. APACHE II was associated with ICU mortality in patients with pulmonary ARDS. ARDS is a common reason of admission to the ICU in critically ill patients with one-quarter of the total number of patients receiving mechanical ventilation being diagnosed with the condition 1 . ARDS also contributes to substantial mortality in the ICU 1 . Various risk factors are associated with ARDS and pulmonary ARDS is frequently encountered in ICU. Pneumonia has been known as the most common etiology of pulmonary ARDS 13 . The co-infection of respiratory virus was found in patients with severe pneumonia admitted to ICU ranging from 13.4% to 49% [3] [4] [5] . The frequency of respiratory viral infection in pulmonary ARDS has not been established. The current study showed similar frequency of respiratory viral infection in pulmonary ARDS as those of severe pneumonia in patients admitted to the ICU. Respiratory viruses play a role in development and progression of ARDS 8 ; therefore, it is important to elucidate the clinical significance of them in patients with pulmonary ARDS. Several studies have reported clinical outcomes in patients infected with respiratory viruses receiving mechanical ventilation [14] [15] [16] [17] . In the present study, clinical outcomes did not differ between patients with infected with influenza virus and those with other respiratory viruses. Similar clinical outcomes were reported in patients with respiratory syncytial virus or rhinovirus compared to influenza virus 17, 18 . In the current study, comparison of clinical outcomes in each respiratory viruses was not performed due to a few cases except for influenza virus. APACHE II score was associated with a 30-day mortality in patients with ARDS infected with respiratory viruses, which suggests that severity of illness has an impact on overall clinical outcomes.