Herpes Simplex Virus and Cytomegalovirus Reactivation Among Severe ARDS Patients Under Veno-venous ECMO

Background: Herpesviridae reactivation among non-immunocompromised critically ill patients is associated with impaired prognosis, especially during acute respiratory distress syndrome (ARDS). However, little is known about herpes simplex virus (HSV) and Cytomegalovirus (CMV) reactivation occurring in patients with severe ARDS under veno-venous extracorporeal membrane oxygenation (ECMO). We tried to determine the frequency of Herpesviridae reactivation and its impact on patients' prognosis during ECMO for severe ARDS.

Results: During a 5-year period, 123 non-immunocompromised patients with a severe ARDS requiring a veno-venous ECMO were included. Sixty-seven patients (54%) experienced HSV and/or CMV reactivation during ECMO course (20 viral co-infection, 40 HSV alone, and 7 CMV alone). HSV reactivation occurred earlier than CMV after the beginning of MV [(6-15) vs. 19 (13-29) days; p < 0.01] and after ECMO implementation [(2-8) vs. 14 (10-20) days; p < 0.01]. In univariate analysis, HSV/CMV reactivation was associated with a longer duration of mechanical ventilation [(22-52.5) vs. 17.5 (9-28) days; p < 0.01], a longer duration of ECMO [15 (10-22.5) vs. 9 (5-14) days; p < 0.01], and a prolonged ICU [29 (19.5-47.5) vs. 16 (9-30) days; p < 0.01] and hospital stay [44 (29-63.5) vs. 24 (11-43) days; p < 0.01] as compared to non-reactivated patients. However, in multivariate analysis, viral reactivation remained associated with prolonged MV only. When considered separately, both HSV and CMV reactivation were associated with a longer duration of MV as compared to non-reactivation patients [29 (19.5-41) and 28 (20.5-37), respectively, vs. 17.5 (9-28) days; p < 0.05]. Co-reactivation patients had a longer duration of MV [58.5 (38-72.3); p < 0.05] and ICU stay [51.5 (32.5-69) vs. 27.5 (17.75-35.5) and 29 (20-30.5), respectively] as compared to patients with HSV or CMV reactivation alone. In multivariate analysis, HSV reactivation remained independently associated with a longer duration of MV and hospital length of stay.

Conclusions: Herpesviridae reactivation is frequent among patients with severe ARDS under veno-venous ECMO and is associated with a longer duration of mechanical ventilation. The direct causative link between HSV and CMV reactivation and respiratory function worsening under ECMO remains to be confirmed.