Viruses in the Respiratory Tract in Elective Cardiac Surgery Patients

Objectives: Acute respiratory distress syndrome after cardiac surgery is a severe complication that is associated with high morbidity and mortality. The presence of viruses in the respiratory tract is postulated to be one of multiple factors attributing to development of Acute Respiratory Distress Syndrome (ARDS), but studies report conflicting results. Since this possible risk factor can potentially be influenced by screening or vaccination, we aimed to further investigate the role of viruses in the development of ARDS after cardiac surgery. Methods: We conducted an explorative prospective cohort study in 49 randomly chosen asymptomatic adult elective cardiac surgery patients. On four different time points, non-fiberscopic mini-broncho alveolar lavages (miniBAL) were collected and analysed with multiplex PCR testing for 11 types of respiratory viruses. Results and Conclusions: Various (merely low pathogenic) respiratory viruses were detected in 12% of our study population. Respiratory viruses were present both within and out of the influenza-like-illness- season. 19 (39%) of all patients developed acute respiratory distress syndrome. No relationship of viral presence with major pulmonary outcomes (PaO2/FiO2 ratio, development of acute respiratory distress syndrome or mechanical ventilation time) could be demonstrated, though events were too few to allow multivariate analyses. Conclusion: Asymptomatic elective cardiac surgery patients do carry respiratory viruses, though not associated with development of respiratory complications. Further research is warranted, in particular research into the (more pathogenic) diverse subtypes of the respiratory viruses, the relevance of virus load (cycle threshold-values) and even into the diagnostic method (throat swab versus deeper material).