ABSTRACT
BACKGROUND: The COVID-19 pandemic led authorities to evacuate via various travel modalities critically ill ventilated patients into less crowded units. However, it is not known if interhospital transport impacts COVID-19 patient's mortality in intensive care units (ICUs). A cohort from three French University Hospitals was analysed in ICUs between 15th of March and the 15th of April 2020. Patients admitted to ICU with positive COVID-19 test and mechanically ventilated were recruited. RESULTS: Among the 133 patients included in the study, 95 (71%) were male patients and median age was 63 years old (interquartile range: 54-71). Overall ICU mortality was 11%. Mode of transport included train (48 patients), ambulance (6 patients), and plane plus helicopter (14 patients). During their ICU stay, 7 (10%) transferred patients and 8 (12%) non-transferred patients died (p = 0.71). Median SAPS II score at admission was 33 (interquartile range: 25-46) for the transferred group and 35 (27-42) for non-transferred patients (p = 0.53). SOFA score at admission was 4 (3-6) for the transferred group versus 3 (2-5) for the non-transferred group (p = 0.25). In the transferred group, median PaO2/FiO2 ratio (P/F) value in the 24 h before departure was 197 mmHg (160-250) and remained 166 mmHg (125-222) in the first 24 h post arrival (p = 0.13). During the evacuation 46 (68%) and 21 (31%) of the patients, respectively, benefited from neuromuscular blocking agents and from vasopressors. Transferred and non-transferred patients had similar rate of nosocomial infections, 37/68 (54%) versus 34/65 (52%), respectively (p = 0.80). Median length of mechanical ventilation was significantly increased in the transferred group compared to the non-transferred group, 18 days (11-24) and 14 days (8-20), respectively (p = 0.007). Finally, ICU and hospital length of stay did not differ between groups. CONCLUSIONS: In France, inter-hospital evacuation of COVID-19 ventilated ICU patients did not appear to increase mortality and therefore could be proposed to manage ICU surges in the future.
ABSTRACT
PURPOSE: The SARS-CoV-2 infection can lead to a severe acute respiratory distress syndrome (ARDS) with prolonged mechanical ventilation and high mortality rate. Interestingly, COVID-19-associated ARDS share biological and clinical features with sepsis-associated immunosuppression since lymphopenia and acquired infections associated with late mortality are frequently encountered. Mechanisms responsible for COVID-19-associated lymphopenia need to be explored since they could be responsible for delayed virus clearance and increased mortality rate among intensive care unit (ICU) patients. METHODS: A series of 26 clinically annotated COVID-19 patients were analyzed by thorough phenotypic and functional investigations at days 0, 4, and 7 after ICU admission. RESULTS: We revealed that, in the absence of any difference in demographic parameters nor medical history between the two groups, ARDS patients presented with an increased number of myeloid-derived suppressor cells (MDSC) and a decreased number of CD8pos effector memory cell compared to patients hospitalized for COVID-19 moderate pneumonia. Interestingly, COVID-19-related MDSC expansion was directly correlated to lymphopenia and enhanced arginase activity. Lastly, T cell proliferative capacity in vitro was significantly reduced among COVID-19 patients and could be restored through arginine supplementation. CONCLUSIONS: The present study reports a critical role for MDSC in COVID-19-associated ARDS. Our findings open the possibility of arginine supplementation as an adjuvant therapy for these ICU patients, aiming to reduce immunosuppression and help virus clearance, thereby decreasing the duration of mechanical ventilation, nosocomial infection acquisition, and mortality.