Virus-induced acute respiratory distress syndrome: epidemiology, management and outcome

The acute respiratory distress syndrome (ARDS) can be induced by viral diseases, with two virus types being responsible: respiratory viruses that cause community-acquired viral pneumonia and Herpesviridae that cause nosocomial viral pneumonia. Among the respiratory viruses that can affect the lung and cause ARDS, pandemic viruses head the list, with influenza viruses H5N1 and H1N1 2009 being the most recently identified. However, other viruses can cause severe ARDS. Notably, a novel coronavirus was responsible for the severe acute respiratory syndrome outbreak in 2003. Apart from these pandemic viruses, respiratory viruses are rarely responsible for viral pneumonia and ARDS. Other than antiviral drug (mainly oseltamivir) administration and avoidance of corticosteroids, management of ARDS due to these viruses does not differ from that for ARDS caused by other diseases. Among Herpesviridae, herpes simplex virus (HSV) and cytomegalovirus (CMV) are the two viruses causing nosocomial viral pneumonia that can evolve into ARDS. HSV is frequently recovered in the respiratory tract of mechanically ventilated patients and can sometimes be responsible for HSV bronchopneumonitis. Although not evaluated for this indication, acyclovir can be a therapeutic option for patients with HSV bronchopneumonitis and ARDS. CMV pneumonia can also occur in mechanically ventilated patients, but is difficult to diagnose because virus recovery does not necessarily mean viral disease. Ganciclovir can be considered for patients with ARDS and histology- or cytology-proven CMV pneumonia.