Background Neurotropism of SARS-CoV-2 and its neurological manifestations have now been confirmed. We aimed at describing delirium and neurological symptoms of COVID-19 in ICU patients. Methods We conducted a bicentric cohort study in two French ICUs of Strasbourg University Hospital. All the 150 patients referred for acute respiratory distress syndrome due to SARS-CoV-2 between March 3 and May 5, 2020, were included at their admission. Ten patients (6.7%) were excluded because they remained under neuromuscular blockers during their entire ICU stay. Neurological examination, including CAM-ICU, and cerebrospinal fluid analysis, electroencephalography, and magnetic resonance imaging (MRI) were performed in some of the patients with delirium and/or abnormal neurological examination. The primary endpoint was to describe the incidence of delirium and/or abnormal neurological examination. The secondary endpoints were to describe the characteristics of delirium, to compare the duration of invasive mechanical ventilation and ICU length of stay in patients with and without delirium and/or abnormal neurological symptoms. Results The 140 patients were aged in median of 62 [IQR 52; 70] years old, with a median SAPSII of 49 [IQR 37; 64] points. Neurological examination was normal in 22 patients (15.7%). One hundred eighteen patients (84.3%) developed a delirium with a combination of acute attention, awareness, and cognition disturbances. Eighty-eight patients (69.3%) presented an unexpected state of agitation despite high infusion rates of sedative treatments and neuroleptics, and 89 (63.6%) patients had corticospinal tract signs. Brain MRI performed in 28 patients demonstrated enhancement of subarachnoid spaces in 17/28 patients (60.7%), intraparenchymal, predominantly white matter abnormalities in 8 patients, and perfusion abnormalities in 17/26 patients (65.4%). The 42 electroencephalograms mostly revealed unspecific abnormalities or diffuse, especially bifrontal, slow activity. Cerebrospinal fluid examination revealed inflammatory disturbances in 18/28 patients, including oligoclonal bands with mirror pattern and elevated IL-6. The CSF RT-PCR SARS-CoV-2 was positive in one patient. The delirium/neurological symptoms in COVID-19 patients were responsible for longer mechanical ventilation compared to the patients without delirium/neurological symptoms. Delirium/neurological symptoms could be secondary to systemic inflammatory reaction to SARS-CoV-2. Conclusions and relevance Delirium/neurological symptoms in COVID-19 patients are a major issue in ICUs, especially in the context of insufficient human and material resources. Trial registration NA.

IMPORTANCEThe benefit of high-dose dexamethasone and oxygenation strategies vs standard of care for patients with severe acute hypoxemic respiratory failure (AHRF) caused by COVID-19 pneumonia is debated.OBJECTIVES To assess the benefit of high-dose dexamethasone compared with standard of care dexamethasone, and to assess the benefit of high-flow nasal oxygen (HFNO 2 ) or continuous positive airway pressure (CPAP) compared with oxygen support standard of care (O 2 SC). DESIGN, SETTING, AND PARTICIPANTSThis multicenter, placebo-controlled randomized clinical trial was conducted in 19 intensive care units (ICUs) in France from April 2020 to January 2021. Eligible patients were consecutive ICU-admitted adults with COVID-19 AHRF. Randomization used a 2 × 3 factorial design for dexamethasone and oxygenation strategies; patients not eligible for at least 1 oxygenation strategy and/or already receiving invasive mechanical ventilation (IMV) were only randomized for dexamethasone. All patients were followed-up for 60 days. Data were analyzed from May 26 to July 31, 2021.INTERVENTIONS Patients received standard dexamethasone (dexamethasone-phosphate 6 mg/d for 10 days [or placebo prior to RECOVERY trial results communication]) or high-dose dexamethasone (dexamethasone-phosphate 20 mg/d on days 1-5 then 10 mg/d on days 6-10). Those not requiring IMV were additionally randomized to O 2 SC, CPAP, or HFNO 2 . MAIN OUTCOMES AND MEASURESThe main outcomes were time to all-cause mortality, assessed at day 60, for the dexamethasone interventions, and time to IMV requirement, assessed at day 28, for the oxygenation interventions. Differences between intervention groups were calculated using proportional Cox models and expressed as hazard ratios (HRs). RESULTS Among 841 screened patients, 546 patients (median [IQR] age, years; 414 [75.8%] men) were randomized between standard dexamethasone (276 patients, including 37 patients who received placebo) or high-dose dexamethasone (270 patients). Of these, 333 patients were randomized among O 2 SC (109 patients, including 56 receiving standard dexamethasone), CPAP (109 patients, including 57 receiving standard dexamethasone), and HFNO 2 (115 patients, including 56 receiving standard dexamethasone). There was no difference in 60-day mortality between standard and high-dose dexamethasone groups (HR, 0.96 [95% CI, 0.69-1.33]; P = .79). There was no significant difference for the cumulative incidence of IMV criteria at day 28 among O 2 support groups (O 2 SC vs CPAP: HR, 1.08 [95% CI, 0.71-1.63]; O 2 SC vs HFNO 2 : HR, 1.04 [95% CI, 0.69-1.55]) or 60-day mortality (O 2 SC vs CPAP: HR, 0.97 [95% CI, 0.58-1.61; O 2 SC vs HFNO 2 : HR, 0.89 [95% CI,). Interactions between interventions were not significant. CONCLUSIONS AND RELEVANCEIn this randomized clinical trial among ICU patients with COVID-19-related AHRF, high-dose dexamethasone did not significantly improve 60-day survival. The oxygenation strategies in patients who were not initially receiving IMV did not significantly modify 28-day risk of...

Impact of the research: Although bilateral phrenic nerve stimulation did not increase the proportion of successful weaning from mechanical ventilation compared to the standard of care, it resulted in substantial improvements in inspiratory pressure generation capacity without major safety issues. In the absence of previous clinical data, these findings suggest that diaphragm pacing could be effective in mitigating diaphragm dysfunction in patients difficult to wean from mechanical ventilation. Author contributions:The academic authors (MD, MGDA, TS) wrote the first draft of the manuscript and verified the underlying data. All authors critically reviewed and approved the manuscript and are accountable its accuracy and integrity. Dr Martin Dres had full access to all the data in the study and takes full responsibility for the integrity of the data and the accuracy of the data analysis. Teresa Nelson conducted and is responsible for the data analysis. Support:The study was funded by Lungpacer Medical Inc, PA, USA.

Background Differences in physiology of ARDS have been described between COVID-19 and non-COVID-19 patients. This study aimed to compare initial values and longitudinal changes in respiratory system compliance (CRS), oxygenation parameters and ventilatory ratio (VR) in patients with COVID-19 and non-COVID-19 pulmonary ARDS matched on oxygenation. Methods 135 patients with COVID-19 ARDS from two centers were included in a physiological study; 767 non-COVID-19 ARDS from a clinical trial were used for the purpose of at least 1:2 matching. A propensity-matching was based on age, severity score, oxygenation, positive end-expiratory pressure (PEEP) and pulmonary cause of ARDS and allowed to include 112 COVID-19 and 198 non-COVID pulmonary ARDS. Results The two groups were similar on initial oxygenation. COVID-19 patients had a higher body mass index, higher CRS at day 1 (median [IQR], 35 [28–44] vs 32 [26–38] ml cmH2O−1, p = 0.037). At day 1, CRS was correlated with oxygenation only in non-COVID-19 patients; 61.6% and 68.2% of COVID-19 and non-COVID-19 pulmonary ARDS were still ventilated at day 7 (p = 0.241). Oxygenation became lower in COVID-19 than in non-COVID-19 patients at days 3 and 7, while CRS became similar. VR was lower at day 1 in COVID-19 than in non-COVID-19 patients but increased from day 1 to 7 only in COVID-19 patients. VR was higher at days 1, 3 and 7 in the COVID-19 patients ventilated using heat and moisture exchangers compared to heated humidifiers. After adjustment on PaO2/FiO2, PEEP and humidification device, CRS and VR were found not different between COVID-19 and non-COVID-19 patients at day 7. Day-28 mortality did not differ between COVID-19 and non-COVID-19 patients (25.9% and 23.7%, respectively, p = 0.666). Conclusions For a similar initial oxygenation, COVID-19 ARDS initially differs from classical ARDS by a higher CRS, dissociated from oxygenation. CRS become similar for patients remaining on mechanical ventilation during the first week of evolution, but oxygenation becomes lower in COVID-19 patients. Trial registration: clinicaltrials.gov NCT04385004