Background There are large uncertainties regarding outcome of patients with COVID-19 and mechanical ventilation (MV). High mortality (50 – 97%) was proposed by some groups, leading to considerable uncertainties regarding outcome of critically ill patients with COVID-19. Objectives The aim was to investigate the characteristics and outcome of critically ill patients with COVID-19 requiring intensive Care Unit (ICU) admission and mechanical ventilation. Methods A multicentre retrospective observational cohort study at 15 hospitals in Hamburg, Germany, was performed. Critically ill adult patients with COVID-19 who completed their ICU stay between February-June 2020 were included. Patient demographics, severity of illness, ICU course were retrospectively evaluated. Results There were 223 critically ill COVID-19 patients included. The majority, 73% (n=163), were male; median age was 69 (IQR 58 - 77.5) years, with 68% (n=151) patients had at least one chronic medical condition. Their SOFA-score was median 5 ( [3] , [4] , [5] , [6] , [7] , [8] , [9] ) points on admission. Overall, 167 (75%) patients needed MV. Non-invasive ventilation (NIV) and high-flow nasal cannula (HFNC) were used in in 31 (14%) and 26 (12%) patients, respectively. Subsequent MV, due to NIV/HFNC failure, was necessary in 46 (81%) patients. Renal replacement therapy was initiated in 33% (n=72), and due to severe respiratory failure extracorporeal membrane oxygenation was necessary in 9% (n=20) of patients. Experimental antiviral-therapy was used in 9% (n=21). Complications during ICU stay were: septic shock (40%, n=90), heart failure (8%, n=17) and pulmonary embolism (6%, n=14). Length of ICU-stay was median 13 days ( [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] ), duration of MV was 15 days ( [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] ...

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Indications for a pivotal role of the thalamocortical network in producing the state of anesthesia have come from in vivo animal studies as well as imaging studies in humans. We studied possible synaptic mechanisms of anesthesia-induced suppression of touch perception in the rat's thalamus. Thalamocortical relay neurons (TCNs) receive ascending and descending glutamatergic excitatory inputs via NMDA and non-NMDA receptors (AMPAR) and are subjected to GABA(A)ergic inhibitory input which shapes the sensory information conveyed to the cortex. The involvement of these synaptic receptors in the suppressive effects of the prototypic volatile anesthetic isoflurane was assessed by local iontophoretic administration of receptor agonists/antagonists during extracellular recordings of TCNs of the ventral posteromedial nucleus responding to whisker vibration in rats anesthetized with isoflurane concentrations of approximately 0.9 vol.% (baseline) and approximately 1.9 vol.% (ISO high). ISO high induced a profound suppression of response activity reflected by a conversion of the sustained vibratory responses to ON responses. Administration of NMDA, AMPA, or GABA(A)R antagonists caused a reversal to sustained responses in 88, 94 and 88% of the neurons, respectively, with a recovery to baseline levels of response activity. The data show that the block of thalamocortical transfer of tactile information under ISO high may result from an enhancement of GABA(A)ergic inhibition and/or a reduction of glutamatergic excitation. Furthermore, they show that the ascending vibratory signals still reach the thalamic neurons under the high isoflurane concentration, indicating that this input is resistant to isoflurane while the attenuation of excitation may be brought about at the corticothalamic glutamatergic facilitatory input.