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Background: This study aimed to assess a potential organ protective effect of volatile sedation in a scenario of severe inflammation with an early cytokine storm (in particular IL-6 elevation) in patients suffering from COVID-19-related lung injury with invasive mechanical ventilation and sedation. Methods: This is a small-scale pilot multicenter randomized controlled trial from four tertiary hospitals in Switzerland, conducted between April 2020 and May 2021. 60 patients requiring mechanical ventilation due to severe COVID-19-related lung injury were included and randomized to 48-hour sedation with sevoflurane vs. continuous intravenous sedation (= control) within 24 h after intubation. The primary composite outcome was determined as mortality or persistent organ dysfunction (POD), defined as the need for mechanical ventilation, vasopressors, or renal replacement therapy at day 28. Secondary outcomes were the length of ICU and hospital stay, adverse events, routine laboratory parameters (creatinine, urea), and plasma inflammatory mediators. Results: 28 patients were randomized to sevoflurane, 32 to the control arm. The intention-to-treat analysis revealed no difference in the primary endpoint with 11 (39%) sevoflurane and 13 (41%) control patients (p = 0.916) reaching the primary outcome. Five patients died within 28 days in each group (16% vs. 18%, p = 0.817). Of the 28-day survivors, 6 (26%) and 8 (30%) presented with POD (p = 0.781). There was a significant difference regarding the need for vasopressors (1 (4%) patient in the sevoflurane arm, 7 (26%) in the control one (p = 0.028)). Length of ICU stay, hospital stay, and registered adverse events within 28 days were comparable, except for acute kidney injury (AKI), with 11 (39%) sevoflurane vs. 2 (6%) control patients (p = 0.001). The blood levels of IL-6 in the first few days after the onset of the lung injury were less distinctly elevated than expected. Conclusions: No evident benefits were observed with short sevoflurane sedation on mortality and POD. Unexpectedly low blood levels of IL-6 might indicate a moderate injury with therefore limited improvement options of sevoflurane. Acute renal issues suggest caution in using sevoflurane for sedation in COVID-19. Trial registration: The trial was registered on ClinicalTrials.gov (NCT04355962) on 2020/04/21. [ABSTRACT FROM AUTHOR]

Background: Endotoxin adsorption is a promising but controversial therapy in severe, refractory septic shock and conflicting results exist on the effective capacity of available devices to reduce circulating endotoxin and inflammatory cytokine levels. Methods: Multiarm, randomized, controlled trial in two Swiss intensive care units, with a 1:1:1 randomization of patients suffering severe, refractory septic shock with high levels of endotoxemia, defined as an endotoxin activity ≥ 0.6, a vasopressor dependency index ≥ 3, volume resuscitation of at least 30 ml/kg/24 h and at least single organ failure, to a haemoadsorption (Toraymyxin), an enhanced adsorption haemofiltration (oXiris) or a control intervention. Primary endpoint was the difference in endotoxin activity at 72-h post-intervention to baseline. In addition, inflammatory cytokine, vasopressor dependency index and SOFA-Score dynamics over the initial 72 h were assessed inter alia. Results: In the 30, out of 437 screened, randomized patients (10 Standard of care, 10 oXiris, 10 Toraymyxin), endotoxin reduction at 72-h post-intervention-start did not differ among interventions (Standard of Care: 12 [1–42]%, oXiris: 21 [10–51]%, Toraymyxin: 23 [10–36]%, p = 0.82). Furthermore, no difference between groups could be observed neither for reduction of inflammatory cytokine levels (p = 0.58), nor for vasopressor weaning (p = 0.95) or reversal of organ injury (p = 0.22). Conclusions: In a highly endotoxemic, severe, refractory septic shock population neither the Toraymyxin adsorber nor the oXiris membrane could show a reduction in circulating endotoxin or cytokine levels over standard of care. Trial registration ClinicalTrials.gov. NCT01948778. Registered August 30, 2013. https://clinicaltrials.gov/study/NCT01948778 [ABSTRACT FROM AUTHOR]

Abstract: The systemic inflammatory response syndrome (SIRS) is triggered by C5a generation following an excessive complement amplification, but it has remained unclear how complement amplification is stimulated. It is known that neutrophilic elastase can cleave IgG to F(ab′)2 and that F(ab′)2-containing immune complexes (F(ab′)2-IC) stimulate complement amplification together with an unidentified plasma factor. We show that absorption of plasma on F(ab′)2 from human IgG removed this factor and prevented F(ab′)2-IC from stimulating complement amplification. The required factor was purified from pooled whole human IgG (IVIG) as those naturally occurring antibodies (NAbs) that bind to F(ab′)2, but not to intact IgG. These “anti-hinge NAbs” restored complement amplification by F(ab′)2-IC in absorbed plasma. Anti-hinge NAbs must have formed secondary, rigidified IC from F(ab′)2-IC, because the F(ab′)2 fragments evidently captured dimeric C3b, known as a potent C3 convertase precursor. This process may also stimulate complement amplification in vivo, because plasma from septic patients at the onset of SIRS indeed contained F(ab′)2 fragments. The concentrations of F(ab′)2 and that of factor Bb, an unbiased measure of complement amplification, correlated linearly with that of released elastase. Moreover, the F(ab′)2 fragments migrated on gelfiltration columns together with anti-hinge NAbs as ICs with MW of up to ∼750kDa, as verified on plasma of each of the nine patients studied. These findings provide for the first time a plausible mechanism of how F(ab′)2-containing immune complexes stimulate complement amplification together with anti-hinge NAbs. The same mechanism may contribute to complement overreaction at the onset of SIRS. [Copyright &y& Elsevier]