Super-infections in COVID-19 patients with acute respiratory distress syndrome (ARDS) on mechanical ventilation were initially reported to be rare. Little is known of their incidence after dexamethasone was introduced as standard care. We aimed to determine the incidence and characteristics of superinfections in mechanically ventilated COVID-19 patients during the course of the COVID-19 pandemic, and explore the possible impact of the introduction of dexamethasone as standard therapy.
In this national, multi-center, observational, retrospective study we included patients ≥ 18 years admitted from March 1 st 2020 to January 31 st 2021 with polymerase chain reaction (PCR)-confirmed SARSCoV-2 infection treated with invasive mechanical ventilation. Data was collected from electronic health records. Patient characteristics, clinical findings, microbiology, length of stay and 90-day survival were examined with backwards stepwise multiple regression.
155 patients (115 men, mean age 62 years, range 26-84 years) were included. 73 patients (47%) had a total of 101 superinfections where pneumonia dominated (70%). Superinfections were more commonly observed in patients receiving dexamethasone (67% vs 30%, p<0.0001), and in patients with pre-existing autoimmune disease (18% vs 5%, p<0.01). Invasive fungal infections were reported exclusively in dexamethasone-treated patients [9/72 (13%) vs 0/83 (0%), p<0.0001]. There was no difference in 90-day survival between patients with and patients without superinfections (64% versus 73%, p=0.238). In multiple regression analysis, superinfection was associated with dexamethasone use [OR 5.35 (2.62–11.35), p<0.001], pre-existing autoimmune disease [OR 4.90 (1.50–19.4), p=0.008] and higher lymphocyte count at the time of admission [OR 2.31 (1.23–4.86), p=0.009].
In critically ill COVID-19 patients receiving invasive ventilation, introduction of dexamethasone as standard of care was strongly and independently associated with superinfections. A focus on this complication is warranted when studying alternative anti-inflammatory therapy.