Barotrauma in COVID-19 acute respiratory distress syndrome: retrospective analysis of the COVADIS prospective multicenter observational database.

BACKGROUND: Despite evidence suggesting a higher risk of barotrauma during COVID-19-related acute respiratory distress syndrome (ARDS) compared to ARDS due to other causes, data are limited about possible associations with patient characteristics, ventilation strategy, and survival. METHODS: This prospective observational multicenter study included consecutive patients with moderate-to-severe COVID-19 ARDS requiring invasive mechanical ventilation and managed at any of 12 centers in France and Belgium between March and December 2020. The primary objective was to determine whether barotrauma was associated with ICU mortality (censored on day 90), and the secondary objective was to identify factors associated with barotrauma. RESULTS: Of 586 patients, 48 (8.2%) experienced barotrauma, including 35 with pneumothorax, 23 with pneumomediastinum, 1 with pneumoperitoneum, and 6 with subcutaneous emphysema. Median time from mechanical ventilation initiation to barotrauma detection was 3 [0-17] days. All patients received protective ventilation and nearly half (23/48) were in volume-controlled mode. Barotrauma was associated with higher hospital mortality (P < 0.001) even after adjustment on age, sex, comorbidities, PaO2/FiO2 at intubation, plateau pressure at intubation, and center (P < 0.05). The group with barotrauma had a lower mean body mass index (28.6 ± 5.8 vs. 30.3 ± 5.9, P = 0.03) and a higher proportion of patients given corticosteroids (87.5% vs. 63.4%, P = 0.001). CONCLUSION: Barotrauma during mechanical ventilation for COVID-19 ARDS was associated with higher hospital mortality.

Management and outcomes of pregnant women admitted to intensive care unit for severe pneumonia related to SARS-CoV-2 infection: the multicenter and international COVIDPREG study.

PURPOSE: Management and outcomes of pregnant women with coronavirus disease 2019 (COVID-19) admitted to intensive care unit (ICU) remain to be investigated. METHODS: A retrospective multicenter study conducted in 32 ICUs in France, Belgium and Switzerland. Maternal management as well as maternal and neonatal outcomes were reported. RESULTS: Among the 187 pregnant women with COVID-19 (33 ± 6 years old and 28 ± 7 weeks' gestation), 76 (41%) were obese, 12 (6%) had diabetes mellitus and 66 (35%) had pregnancy-related complications. Standard oxygenation, high-flow nasal oxygen therapy (HFNO) and non-invasive ventilation (NIV) were used as the only oxygenation technique in 41 (22%), 55 (29%) and 18 (10%) patients, respectively, and 73 (39%) were intubated. Overall, 72 (39%) patients required several oxygenation techniques and 15 (8%) required venovenous extracorporeal membrane oxygenation. Corticosteroids and tocilizumab were administered in 157 (84%) and 25 (13%) patients, respectively. Awake prone positioning or prone positioning was performed in 49 (26%) patients. In multivariate analysis, risk factors for intubation were obesity (cause-specific hazard ratio (CSH) 2.00, 95% CI (1.05-3.80), p = 0.03), term of pregnancy (CSH 1.07, 95% CI (1.02-1.10), per + 1 week gestation, p = 0.01), extent of computed tomography (CT) scan abnormalities > 50% (CSH 2.69, 95% CI (1.30-5.60), p < 0.01) and NIV use (CSH 2.06, 95% CI (1.09-3.90), p = 0.03). Delivery was required during ICU stay in 70 (37%) patients, mainly due to maternal respiratory worsening, and improved the driving pressure and oxygenation. Maternal and fetal/neonatal mortality rates were 1% and 4%, respectively. The rate of maternal and/or neonatal complications increased with the invasiveness of maternal respiratory support. CONCLUSION: In ICU, corticosteroids, tocilizumab and prone positioning were used in few pregnant women with COVID-19. Over a third of patients were intubated and delivery improved the driving pressure.

Early Corticosteroid Therapy May Increase Ventilator-Associated Lower Respiratory Tract Infection in Critically Ill Patients with COVID-19: A Multicenter Retrospective Cohort Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has put significant pressure on hospitals and in particular on intensive care units (ICU). Some patients develop acute hypoxemic respiratory failure with profound hypoxia, which likely requires invasive mechanical ventilation during prolonged periods. Corticosteroids have become a cornerstone therapy for patients with severe COVID-19, though only little data are available regarding their potential harms and benefits, especially concerning the risk of a ventilator-associated lower respiratory tract infection (VA-LRTI). METHODS: This retrospective multicenter study included patients admitted in four ICUs from Belgium and France for severe COVID-19, who required invasive mechanical ventilation (MV). We compared clinical and demographic variables between patients that received corticosteroids or not, using univariate, multivariate, and Fine and Gray analyses to identify factors influencing VA-LRTI occurrence. RESULTS: From March 2020 to January 2021, 341 patients required MV for acute respiratory failure related to COVID-19, 322 of whom were included in the analysis, with 60.6% of them receiving corticosteroids. The proportion of VA-LRTI was significantly higher in the early corticosteroid group (63.1% vs. 48.8%, p = 0.011). Multivariable Fine and Gray modeling considering death and extubation as competing events revealed that the factors independently associated with VA-LRTI occurrence were male gender (adjusted sHR:1.7, p = 0.0022) and corticosteroids (adjusted sHR: 1.44, p = 0.022). CONCLUSIONS: in our multicenter retrospective cohort of COVID-19 patients undergoing MV, early corticosteroid therapy was independently associated with VA-LRTI.

Red Blood Cell Shape and Deformability in Patients With COVID-19 Acute Respiratory Distress Syndrome.

Background: Acute respiratory distress syndrome due to coronavirus disease 2019 (COVID-19) is associated with high mortality. Several studies have reported that the microcirculation responds adequately to hypoxia in COVID-19 patients by increasing oxygen availability, in contrast to the inadequate response observed in patients with bacterial sepsis. Red blood cells (RBCs), the key cells for oxygen transport, and notably their rheology, are altered during bacterial sepsis, but few data are available in patients with COVID-19. Methods: In this prospective, non-interventional study, shape was assessed on admission (or inclusion for the volunteers) using Pearson's second coefficient of dissymmetry (PCD) on the histogram obtained with a flow cytometer technique. A null value represents a perfect spherical shape. RBC deformability was determined using ektacytometry by the elongation index in relation to the shear stress (0.3 to 50 Pa) applied to the RBC membrane. A higher elongation index indicates greater RBC deformability. Results were compared across groups. Scanning electronic microscopy was performed on RBCs from COVID-19 patients. RBC shape and deformability were also assessed on days 3 and 7 in COVID-19 patients. Results: Forty-nine ICU patients were included (30 with COVID-19 ARDS and 19 with bacterial sepsis). ARDS was more severe in patients with COVID-19 than in those with sepsis (PaO2/FiO2 99 [73-154] vs. 270 [239-295] mmHg p < 0.001) and mechanical ventilation was more frequently required (87 vs. 21%; p < 0.001). Mortality was significantly higher in COVID-19 patients (15/30 [50%] vs. 4/19 [21%], p = 0.046). RBCs were significantly more spherical in septic patients (PCD -0.40 [-0.56; -0.18]) than in healthy volunteers (PCD -0.54 [-0.66; -0.49]) but not than in COVID-19 patients (-0.48 [-0.55; -0.43]). In COVID-19 non-survivors (n = 11), sphericity was more marked on day 7 (PCD -0.40 [-0.47; -0.28]) than on day 1 (PCD vs. -0.49 [-0.59; -0.44]); p = 0.045. At ICU admission, RBC deformability was altered for all shear stress values studied in septic patients compared to COVID-19 patients and healthy volunteers (maximum elongation index for septic patients: 0.600 [0.594-0.630] vs. 0.646 [0.637-0.653] for COVID-19 patients and 0.640 [0.635-0.650] for healthy volunteers; both p < 0.001). In the 18 COVID-19 patients studied for 7 days, RBC deformability did not change over time and was not related to outcome. At day 1, RBCs from COVID-19 patients showed a normal structure on scanning electronic microscopy. Conclusion: In contrast to the significantly altered shape and decreased deformability in patients with bacterial sepsis, RBCs from severely hypoxemic COVID-19 patients had normal deformability on admission, and this pattern did not change over the first week despite a more spherical shape in non-survivors. As RBCs are the key cell for oxygen transport, this maintenance of normal deformability may contribute to the adequate microcirculatory response to severe hypoxia of the microcirculation that has been observed in these patients.

What Do We Know about Thromboprophylaxis and Its Monitoring in Critically Ill Patients?

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is an important complication in patients hospitalized in intensive care units (ICU). Thromboprophylaxis is mainly performed with Low Molecular Weight Heparin (LMWH) and, in some specific patients, with Unfractionated Heparin (UFH). These intensive units are an environment where individual patient variability is extreme and where traditional antithrombotic protocols are frequently ineffective. This was known for a long time, but the hospitalization of many patients with COVID-19 inflammatory storms suddenly highlighted this knowledge. It is therefore reasonable to propose variable antithrombotic prevention protocols based initially on a series of individual criteria (weight, BMI, and thrombotic risks). Secondly, they should be adjusted by the monitoring of anticoagulant activity, preferably by measuring the anti-Xa activity. However, we still face unresolved questions, such as once- or twice-daily LMWH injections, monitoring at the peak and/or trough, and poorly defined therapeutic targets. Equally surprisingly, we observed a lack of standardization of the anti-Xa activity kits.

Identifying Clinical Phenotypes in Moderate to Severe Acute Respiratory Distress Syndrome Related to COVID-19: The COVADIS Study.

Objectives: Different phenotypes have been identified in acute respiratory distress syndrome (ARDS). Existence of several phenotypes in coronavirus disease (COVID-19) related acute respiratory distress syndrome is unknown. We sought to identify different phenotypes of patients with moderate to severe ARDS related to COVID-19. Methods: We conducted an observational study of 416 COVID-19 patients with moderate to severe ARDS at 21 intensive care units in Belgium and France. The primary outcome was day-28 ventilatory free days. Secondary outcomes were mortality on day 28, acute kidney injury, acute cardiac injury, pulmonary embolism, and deep venous thrombosis. Multiple factor analysis and hierarchical classification on principal components were performed to distinguish different clinical phenotypes. Results: We identified three different phenotypes in 150, 176, and 90 patients, respectively. Phenotype 3 was characterized by short evolution, severe hypoxemia, and old comorbid patients. Phenotype 1 was mainly characterized by the absence of comorbidities, relatively high compliance, and long duration of symptoms, whereas phenotype 2 was characterized female sex, and the presence of mild comorbidities such as uncomplicated diabetes or chronic hypertension. The compliance in phenotype 2 was lower than that in phenotype 1, with higher plateau and driving pressure. Phenotype 3 was associated with higher mortality compared to phenotypes 1 and 2. Conclusions: In COVID-19 patients with moderate to severe ARDS, we identified three clinical phenotypes. One of these included older people with comorbidities who had a fulminant course of disease with poor prognosis. Requirement of different treatments and ventilatory strategies for each phenotype needs further investigation.

Static compliance of the respiratory system in COVID-19 related ARDS: an international multicenter study.

BACKGROUND: Controversies exist on the nature of COVID-19 related acute respiratory distress syndrome (ARDS) in particular on the static compliance of the respiratory system (Crs). We aimed to analyze the association of Crs with outcome in COVID-19-associated ARDS, to ascertain its determinants and to describe its evolution at day-14. METHODS: In this observational multicenter cohort of patients with moderate to severe Covid-19 ARDS, Crs was measured at day-1 and day-14. Association between Crs or Crs/ideal body weight (IBW) and breathing without assistance at day-28 was analyzed with multivariable logistic regression. Determinants were ascertained by multivariable linear regression. Day-14 Crs was compared to day-1 Crs with paired t-test in patients still under controlled mechanical ventilation. RESULTS: The mean Crs in 372 patients was 37.6 ± 13 mL/cmH2O, similar to as in ARDS of other causes. Multivariate linear regression identified chronic hypertension, low PaO2/FiO2 ratio, low PEEP, and low tidal volume as associated with lower Crs/IBW. After adjustment on confounders, nor Crs [OR 1.0 (CI 95% 0.98-1.02)] neither Crs/IBW [OR 0.63 (CI 95% 0.13-3.1)] were associated with the chance of breathing without assistance at day-28 whereas plateau pressure was [OR 0.93 (CI 95% 0.88-0.99)]. In a subset of 108 patients, day-14 Crs decreased compared to day-1 Crs (31.2 ± 14.4 mL/cmH2O vs 37.8 ± 11.4 mL/cmH2O, p < 0.001). The decrease in Crs was not associated with day-28 outcome. CONCLUSION: In a large multicenter cohort of moderate to severe COVID-19 ARDS, mean Crs was decreased below 40 mL/cmH2O and was not associated with day-28 outcome. Crs decreased between day-1 and day-14 but the decrease was not associated with day-28 outcome.

Factors Associated With Pulmonary Embolism Among Coronavirus Disease 2019 Acute Respiratory Distress Syndrome: A Multicenter Study Among 375 Patients.

Risk factors associated with pulmonary embolism in coronavirus disease 2019 acute respiratory distress syndrome patients deserve to be better known. We therefore performed a post hoc analysis from the COronaVirus-Associated DIsease Study (COVADIS) project, a multicenter observational study gathering 21 ICUs from France (n = 12) and Belgium (n = 9). Three-hundred seventy-five consecutive patients with moderate-to-severe acute respiratory distress syndrome and positive coronavirus disease 2019 were included in the study. At day 28, 15% were diagnosed with pulmonary embolism. Known risk factors for pulmonary embolism including cancer, obesity, diabetes, hypertension, and coronary artery disease were not associated with pulmonary embolism. In the multivariate analysis, younger age (< 65 yr) (odds ratio, 2.14; 1.17-4.03), time between onset of symptoms and antiviral administration greater than or equal to 7 days (odds ratio, 2.39; 1.27-4.73), and use of neuromuscular blockers greater than or equal to 7 days (odds ratio, 1.89; 1.05-3.43) were independently associated with pulmonary embolism. These new findings reinforce the need for prospective studies that will determine the predictors of pulmonary embolism among patients with severe coronavirus disease 2019.

Characteristics and outcomes of acute respiratory distress syndrome related to COVID-19 in Belgian and French intensive care units according to antiviral strategies: the COVADIS multicentre observational study.

BACKGROUND: Limited data are available regarding antiviral therapy efficacy in most severe patients under mechanical ventilation for Covid-19-related acute respiratory distress syndrome (ARDS). METHODS: Comparison of antiviral strategies (none, hydroxychloroquine (OHQ), lopinavir/ritonavir (L/R), others (combination or remdesivir) in an observational multicentre cohort of patients with moderate-to-severe Covid-19 ARDS. The primary endpoint was the number of day 28 ventilator-free days (VFD). Patients who died before d28 were considered as having 0 VFD. The variable was dichotomized into "patients still ventilated or dead at day 28" versus "patients weaned and alive at day 28". RESULTS: We analyzed 415 patients (85 treated with standard of care (SOC), 57 with L/R, 220 with OHQ, and 53 others). The median number of d28-VFD was 0 (IQR 0-13) and differed between groups (P = 0.03), SOC patients having the highest d28-VFD. After adjustment for age, sex, Charlson Comorbidity Index, PaO2/FiO2 ratio and plateau pressure and accounting for center effect with a generalized linear mixed model, none of the antiviral strategies increased the chance of being alive and weaned from MV at day 28 compared to the SOC strategy (OR 0.48 CI95% (0.18-1.25); OR 0.96 (0.47-2.02) and OR 1.43 (0.53-4.04) for L/R, OHQ and other treatments, respectively). Acute kidney injury during ICU stay was frequent (55%); its incidence was higher in patients receiving lopinavir (66 vs 53%, P = 0.03). After adjustment for age, sex, BMI, chronic hypertension and chronic renal disease, the use of L/R was associated with an increased risk of renal replacement therapy (RRT). (OR 2.52 CI95% 1.16-5.59). CONCLUSION: In this multicentre observational study of moderate-to-severe Covid-19 ARDS patients, we did not observe any benefit among patients treated with OHQ or L/R compared with SOC. The use of L/R treatment was associated with an increased need for RRT. Take home message Neither hydroxychloroquine nor lopinavir/ritonavir as COVID-19 antiviral treatment is associated with higher ventilator-free days at day 28 when compared with standard of care (no antiviral treatment) in ICU patients under invasive mechanical ventilation. Lopinavir/ritonavir is associated with an increased risk of renal replacement therapy requirement. Tweet COVID-19: Insights from ARDS cohort: no signal of efficacy of any antiviral drugs. Lopinavir/ritonavir may be associated with need for RRT.

Heme oxygenase-1 (HO-1) cytoprotective pathway: A potential treatment strategy against coronavirus disease 2019 (COVID-19)-induced cytokine storm syndrome.

The outbreak of coronavirus disease 2019 (COVID-19) requires urgent need for effective treatment. Severe COVID-19 is characterized by a cytokine storm syndrome with subsequent multiple organ failure (MOF) and acute respiratory distress syndrome (ARDS), which may lead to intensive care unit and increased risk of death. While awaiting a vaccine, targeting COVID-19-induced cytokine storm syndrome appears currently as the efficient strategy to reduce the mortality of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The stress-responsive enzyme, heme oxygenase-1 (HO-1) is largely known to protect against inflammatory response in animal models. HO-1 is induced by hemin, a well-tolerated molecule, used for decades in the treatment of acute intermittent porphyria. Experimental studies showed that hemin-induced HO-1 mitigates cytokine storm and lung injury in mouse models of sepsis and renal ischemia-reperfusion injury. Furthermore, HO-1 may also control numerous viral infections by inhibiting virus replication. In this context, we suggest the hypothesis that HO-1 cytoprotective pathway might be a promising target to control SARS-CoV-2 infection and mitigate COVID-19-induced cytokine storm and subsequent ARDS.

Thromboprophylaxis in Critically Ill Coronavirus Disease 2019 Patients.

It is now reported that coronavirus disease 2019 ICU patients are at increased risk of thrombosis. Expert opinion and scientific societies recommend a higher dose of low-molecular-weight heparin, but definitive data is lacking. We report our adapted thromboprophylaxis practice of low-molecular-weight heparin administration in coronavirus disease 2019 ICU patients. One-hundred six measurements in 19 ICU patients were collected. Despite enoxaparin 60 mg once daily, only two measurements of the trough anti-Xa were in the upper end of prophylactic range. Anti-Xa activity peaks increased significantly after administration, but all measurements were under the optimal prophylactic ranges. Despite an adapted protocol, three of the 19 patients (16%) developed venous thromboembolism. We show in coronavirus disease 2019 ICU patients, despite higher prophylactic low-molecular-weight heparin administration due to body mass index, anti-Xa activity was well below peak serum levels in our cohort of critically ill coronavirus disease 2019 patients. This evaluation suggests the need for rapid studies on adequate thromboprophylaxis in these patients.