Spontaneous pneumomediastinum: a surrogate of P-SILI in critically ill COVID-19 patients.

Spontaneous pneumomediastinum (SP) has been described early during the COVID-19 pandemic in large series of patients with severe pneumonia, but most patients were receiving invasive mechanical ventilation (IMV) at the time of SP diagnosis. In this retrospective multicenter observational study, we aimed at describing the prevalence and outcomes of SP during severe COVID-19 with pneumonia before any IMV, to rule out mechanisms induced by IMV in the development of pneumomediastinum.Among 549 patients, 21 patients (4%) developed a SP while receiving non-invasive respiratory support, after a median of 6 days [4-12] from ICU admission. The proportion of patients requiring IMV was similar. However, the time to tracheal intubation was longer in patients with SP (6 days [5-13] vs. 2 days [1-4]; P = 0.00002), with a higher first-line use of non-invasive ventilation (n = 11; 52% vs. n = 150; 28%; P = 0.02). The 21 patients who developed a SP had persisting signs of severe lung disease and respiratory failure with lower ROX index between ICU admission and occurrence of SP (3.94 [3.15-5.55] at admission vs. 3.25 [2.73-4.02] the day preceding SP; P = 0.1), which may underline potential indirect signals of Patient-self inflicted lung injury (P-SILI).In this series of critically ill COVID-19 patients, the prevalence of SP without IMV was not uncommon, affecting 4% of patients. They received more often vasopressors and had a longer ICU length of stay, as compared with their counterparts. One pathophysiological mechanism may potentially be carried out by P-SILI related to a prolonged respiratory failure, as underlined by a delayed use of IMV and the evolution of the ROX index between ICU admission and the day preceding SP.

Elevated plasma IL-6 and CRP levels are associated with adverse clinical outcomes and death in critically ill SARS-CoV-2 patients: inflammatory response of SARS-CoV-2 patients.

BACKGROUND: SARS coronavirus 2 (SARS-CoV-2) is responsible for high morbidity and mortality worldwide, mostly due to the exacerbated inflammatory response observed in critically ill patients. However, little is known about the kinetics of the systemic immune response and its association with survival in SARS-CoV-2+ patients admitted in ICU. We aimed to compare the immuno-inflammatory features according to organ failure severity and in-ICU mortality. METHODS: Six-week multicentre study (N = 3) including SARS-CoV-2+ patients admitted in ICU. Analysis of plasma biomarkers at days 0 and 3-4 according to organ failure worsening (increase in SOFA score) and 60-day mortality. RESULTS: 101 patients were included. Patients had severe respiratory diseases with PaO2/FiO2 of 155 [111-251] mmHg), SAPS II of 37 [31-45] and SOFA score of 4 [3-7]. Eighty-three patients (83%) required endotracheal intubation/mechanical ventilation and among them, 64% were treated with prone position. IL-1ß was barely detectable. Baseline IL-6 levels positively correlated with organ failure severity. Baseline IL-6 and CRP levels were significantly higher in patients in the worsening group than in the non-worsening group (278 [70-622] vs. 71 [29-153] pg/mL, P < 0.01; and 178 [100-295] vs. 100 [37-213] mg/L, P < 0.05, respectively). Baseline IL-6 and CRP levels were significantly higher in non-survivors compared to survivors but fibrinogen levels and lymphocyte counts were not different between groups. After adjustment on SOFA score and time from symptom onset to first dosage, IL-6 and CRP remained significantly associated with mortality. IL-6 changes between Day 0 and Day 3-4 were not different according to the outcome. A contrario, kinetics of CRP and lymphocyte count were different between survivors and non-survivors. CONCLUSIONS: In SARS-CoV-2+ patients admitted in ICU, a systemic pro-inflammatory signature was associated with clinical worsening and 60-day mortality.