Substantial heterogeneity of inflammatory cytokine production and its inhibition by a triple cocktail of toll-like receptor blockers in early sepsis

IntroductionEarly sepsis is a life-threatening immune dysregulation believed to feature a “cytokine storm” due to activation of pattern recognition receptors by pathogen and danger associated molecular patterns. However, treatments with single toll-like receptor (TLR) blockers have shown no clinical benefit. We speculated that sepsis patients at the time of diagnosis are heterogeneous in relation to their cytokine production and its potential inhibition by a triple cocktail of TLR blockers. Accordingly, we analyzed inflammatory cytokine production in whole blood assays from early sepsis patients and determined the effects of triple TLR-blockade.MethodsWhole blood of 51 intensive care patients sampled within 24h of meeting Sepsis-3 criteria was incubated for 6h without or with specific TLR2, 4, and 7/8 stimuli or suspensions of heat-killed S. aureus or E. coli bacteria as pan-TLR challenges, and also with a combination of monoclonal antibodies against TLR2 and 4 and chloroquine (endosomal TLR inhibition), subsequent to dose optimization. Concentrations of tumor necrosis factor (TNF), Interleukin(IL)-6, IL-8, IL-10, IL-1α and IL-1β were measured (multiplex ELISA) before and after incubation. Samples from 11 sex and age-matched healthy volunteers served as controls and for dose-finding studies.ResultsOnly a fraction of sepsis patient samples revealed ongoing cytokine production ex vivo despite sampling within 24 h of first meeting Sepsis-3 criteria. In dose finding studies, inhibition of TLR2, 4 and endosomal TLRs reliably suppressed cytokine production to specific TLR agonists and added bacteria. However, inflammatory cytokine production ex vivo was only suppressed in the high cytokine producing samples but not in the majority. The suppressive response to TLR-blockade correlated both with intraassay inflammatory cytokine production (r=0.29–0.68; p<0.0001–0.04) and cytokine baseline concentrations (r=0.55; p<0.0001).DiscussionUpon meeting Sepsis-3 criteria for less than 24 h, a mere quarter of patient samples exhibits a strong inflammatory phenotype, as characterized by increased baseline inflammatory cytokine concentrations and a stark TLR-dependent increase upon further ex vivo incubation. Thus, early sepsis patient cohorts as defined by Sepsis-3 criteria are very heterogeneous in regard to inflammation. Accordingly, proper ex vivo assays may be useful in septic individuals before embarking on immunomodulatory treatments

Impaired upper airway integrity by residual neuromuscular blockade: Increased airway collapsibility and blunted genioglossus muscle activity in response to negative pharyngeal pressure

Background: Residual neuromuscular blockade increases the risk to develop postoperative complications. The authors hypothesized that minimal neuromuscular blockade (train-of-four [TOF] ratio 0.5-1) increases upper airway collapsibility and impairs upper airway dilator muscle compensatory responses to negative pharyngeal pressure challenges. Methods: Epiglottic and nasal mask pressures, genioglossus electromyogram, respiratory timing, and changes in lung volume were measured in awake healthy volunteers (n =3D 15) before, during (TOF =3D 0.5 and 0.8 [steady state]), and after recovery of TOF to unity from rocuronium-induced partial neuromuscular blockade. Passive upper airway closing pressure (negative pressure drops, random order, range +2 to -30 cm H2O) and pressure threshold for flow limitation were determined. Results: Upper airway closing pressure increased (was less negative) significantly from baseline by 54 +/- 4.4% (means +/- SEM), 37 +/- 4.2%, and 16 +/- 4.1% at TOF ratios of 0.5, 0.8, and 1.0, respectively (P < 0.01 vs. baseline for any level). Phasic genioglossus activity almost quadrupled in response to negative (-20 cm H2O) pharyngeal pressure at baseline, and this increase was significantly impaired by 57 +/- 44% and 32 +/- 6% at TOF ratios of 0.5 and 0.8, respectively (P < 0.01 vs. baseline). End-expiratory lung volume, respiratory rate, and tidal volume did not change. Conclusion: Minimal neuromuscular blockade markedly increases upper airway closing pressure, partly by impairing the genioglossus muscle compensatory response. Increased airway collapsibility despite unaffected values for resting ventilation may predispose patients to postoperative respiratory complications, particularly during airway challenges. (C) 2009 American Society of Anesthesiologists, Inc

Comparison of mortality prediction models in acute respiratory distress syndrome undergoing extracorporeal membrane oxygenation and development of a novel prediction score: the PREdiction of Survival on ECMO Therapy-Score (PRESET-Score)

Abstract Background Extracorporeal membrane oxygenation (ECMO) is a life-saving therapy in acute respiratory distress syndrome (ARDS) patients but is associated with complications and costs. Here, we validate various scores supposed to predict mortality and develop an optimized categorical model. Methods In a derivation cohort, 108 ARDS patients (2010–2015) on veno-venous ECMO were retrospectively analysed to assess four established risk scores (ECMOnet-Score, RESP-Score, PRESERVE-Score, Roch-Score) for mortality prediction (receiver operating characteristic analysis) and to identify by multivariable logistic regression analysis independent variables for mortality to yield the new PRESET-Score (PREdiction of Survival on ECMO Therapy-Score). This new score was then validated both in independent internal (n = 82) and external (n = 59) cohorts. Results The median (25%; 75% quartile) Sequential Organ Failure Assessment score was 14 (12; 16), Simplified Acute Physiology Score II was 62.5 (57; 72.8), median intensive care unit stay was 17 days (range 1–124), and mortality was 62%. Only the ECMOnet-Score (area under curve (AUC) 0.69) and the RESP-Score (AUC 0.64) discriminated survivors and non-survivors. Admission pHa, mean arterial pressure, lactate, platelet concentrations, and pre-ECMO hospital stay were independent predictors of death and were used to build the PRESET-Score. The score’s internal (AUC 0.845; 95% CI 0.76–0.93; p < 0.001) and external (AUC 0.70; 95% CI 0.56–0.84; p = 0.008) validation revealed excellent discrimination. Conclusions While our data confirm that both the ECMOnet-Score and the RESP-Score predict mortality in ECMO-treated ARDS patients, we propose a novel model also incorporating extrapulmonary variables, the PRESET-Score. This score predicts mortality much better than previous scores and therefore is a more precise choice for decision support in ARDS patients to be placed on ECMO

Prevalence of COVID-19 Associated Mucormycosis in a German Tertiary Care Hospital

Due to Coronavirus disease (COVID-19) a new group of patients at risk emerged with COVID-19-associated mucormycosis (CAM). Systematic studies, evaluating the prevalence of CAM are missing. To assess CAM prevalence in a tertiary care hospital in Germany, we applied direct microscopy, fungal culture and quantitative realtime in-house PCR targeting Mucorales-specific fragments of 18S and 28S rRNA on respiratory specimens of 100 critically ill COVID-19 patients. Overall, one Mucorales-PCR positive bronchoalevolar lavage was found whereas direct microscopy and fungal culture were negative in all cases. We conclude that a routine screening for CAM in Germany is not indicated