Distinct immunological signatures discriminate severe COVID-19 from non-SARS-CoV-2-driven critical pneumonia.

Immune profiling of COVID-19 patients has identified numerous alterations in both innate and adaptive immunity. However, whether those changes are specific to SARS-CoV-2 or driven by a general inflammatory response shared across severely ill pneumonia patients remains unknown. Here, we compared the immune profile of severe COVID-19 with non-SARS-CoV-2 pneumonia ICU patients using longitudinal, high-dimensional single-cell spectral cytometry and algorithm-guided analysis. COVID-19 and non-SARS-CoV-2 pneumonia both showed increased emergency myelopoiesis and displayed features of adaptive immune paralysis. However, pathological immune signatures suggestive of T cell exhaustion were exclusive to COVID-19. The integration of single-cell profiling with a predicted binding capacity of SARS-CoV-2 peptides to the patients' HLA profile further linked the COVID-19 immunopathology to impaired virus recognition. Toward clinical translation, circulating NKT cell frequency was identified as a predictive biomarker for patient outcome. Our comparative immune map serves to delineate treatment strategies to interfere with the immunopathologic cascade exclusive to severe COVID-19.

A key role for platelet GPVI in neutrophil recruitment, migration, and NETosis in the early stages of acute lung injury.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with high morbidity and mortality. Excessive neutrophil infiltration into the pulmonary airspace is the main cause for the acute inflammation and lung injury. Platelets have been implicated in the pathogenesis of ALI/ARDS, but the underlying mechanisms are not fully understood. Here, we show that the immunoreceptor tyrosine-based activation motif-coupled immunoglobulin-like platelet receptor, glycoprotein VI (GPVI), plays a key role in the early phase of pulmonary thrombo-inflammation in a model of lipopolysaccharide (LPS)-induced ALI in mice. In wild-type (WT) control mice, intranasal LPS application triggered severe pulmonary and blood neutrophilia, hypothermia, and increased blood lactate levels. In contrast, GPVI-deficient mice as well as anti-GPVI-treated WT mice were markedly protected from pulmonary and systemic compromises and showed no increased pulmonary bleeding. High-resolution multicolor microscopy of lung sections and intravital confocal microcopy of the ventilated lung revealed that anti-GPVI treatment resulted in less stable platelet interactions with neutrophils and overall reduced platelet-neutrophil complex (PNC) formation. Anti-GPVI treatment also reduced neutrophil crawling and adhesion on endothelial cells, resulting in reduced neutrophil transmigration and alveolar infiltrates. Remarkably, neutrophil activation was also diminished in anti-GPVI-treated animals, associated with strongly reduced formation of PNC clusters and neutrophil extracellular traps (NETs) compared with that in control mice. These results establish GPVI as a key mediator of neutrophil recruitment, PNC formation, and NET formation (ie, NETosis) in experimental ALI. Thus, GPVI inhibition might be a promising strategy to reduce the acute pulmonary inflammation that causes ALI/ARDS.

Targeting Gαi2 in neutrophils protects from myocardial ischemia reperfusion injury.

Neutrophils are not only involved in immune defense against infection but also contribute to the exacerbation of tissue damage after ischemia and reperfusion. We have previously shown that genetic ablation of regulatory Gαi proteins in mice has both protective and deleterious effects on myocardial ischemia reperfusion injury (mIRI), depending on which isoform is deleted. To deepen and analyze these findings in more detail the contribution of Gαi2 proteins in resident cardiac vs circulating blood cells for mIRI was first studied in bone marrow chimeras. In fact, the absence of Gαi2 in all blood cells reduced the extent of mIRI (22,9% infarct size of area at risk (AAR) Gnai2-/- → wt vs 44.0% wt → wt; p < 0.001) whereas the absence of Gαi2 in non-hematopoietic cells increased the infarct damage (66.5% wt → Gnai2-/- vs 44.0% wt → wt; p < 0.001). Previously we have reported the impact of platelet Gαi2 for mIRI. Here, we show that infarct size was substantially reduced when Gαi2 signaling was either genetically ablated in neutrophils/macrophages using LysM-driven Cre recombinase (AAR: 17.9% Gnai2fl/fl LysM-Cre+/tg vs 42.0% Gnai2fl/fl; p < 0.01) or selectively blocked with specific antibodies directed against Gαi2 (AAR: 19.0% (anti-Gαi2) vs 49.0% (IgG); p < 0.001). In addition, the number of platelet-neutrophil complexes (PNCs) in the infarcted area were reduced in both, genetically modified (PNCs: 18 (Gnai2fl/fl; LysM-Cre+/tg) vs 31 (Gnai2fl/fl); p < 0.001) and in anti-Gαi2 antibody-treated (PNCs: 9 (anti-Gαi2) vs 33 (IgG); p < 0.001) mice. Of note, significant infarct-limiting effects were achieved with a single anti-Gαi2 antibody challenge immediately prior to vessel reperfusion without affecting bleeding time, heart rate or cellular distribution of neutrophils. Finally, anti-Gαi2 antibody treatment also inhibited transendothelial migration of human neutrophils (25,885 (IgG) vs 13,225 (anti-Gαi2) neutrophils; p < 0.001), collectively suggesting that a therapeutic concept of functional Gαi2 inhibition during thrombolysis and reperfusion in patients with myocardial infarction should be further considered.

Plexin C1 influences immune response to intracellular LPS and survival in murine sepsis.

BACKGROUND: Intracellular sensing of lipopolysaccharide (LPS) is essential for the immune response against gram-negative bacteria and results in activation of caspase-11 and pyroptotic cell death with fatal consequences in sepsis. We found the neuronal guidance receptor plexin C1 (PLXNC1) influences the intracellular response to LPS. METHODS: We employed a murine model of sepsis via cecal ligation and binding (CLP), using PLXNC1-/- mice and littermate controls, and additionally transfected murine bone-marrow-derived macrophages (BMDMs) from both genotypes with LPS to achieve activation of the noncanonical inflammasome ex vivo. Additionally, we transfected the PLXNC1 ligand SL4c-d in vivo and ex vivo to examine its effect on intracellular LPS response. RESULTS: We found the neuronal guidance receptor PLXNC1 dampens the intracellular response to LPS by interacting with adenylate cyclase 4 (ADCY4) and protein kinase A activity, which in turn diminishes caspase-11 expression. The absence of PLXNC1 results in excessive inflammation marked by increased cytokine release, increased secondary organ injury and reduced sepsis survival in a murine sepsis model induced by CLP. Notably, administration of SL4c-d-peptide ligand of PLXNC1-reduces the inflammatory response during CLP-induced sepsis and improves survival. CONCLUSIONS: These results elucidate a previously unknown mechanism for PLXNC1 suppressing excessive noncanonical inflammasome activity and offer a new potential target for treatment of sepsis with its detrimental effects.

Impact of P-selectin-PSGL-1 Axis on Platelet-Endothelium-Leukocyte Interactions in Fatal COVID-19.

In critically ill patients infected with SARS-CoV-2, early leukocyte recruitment to the respiratory system was found to be orchestrated by leukocyte trafficking molecules accompanied by massive secretion of proinflammatory cytokines and hypercoagulability. Our study aimed to explore the interplay between leukocyte activation and pulmonary endothelium in different disease stages of fatal COVID-19. Our study comprised 10 COVID-19 postmortem lung specimens and 20 control lung samples (5 acute respiratory distress syndrome, 2 viral pneumonia, 3 bacterial pneumonia, and 10 normal), which were stained for antigens representing the different steps of leukocyte migration: E-selectin, P-selectin, PSGL-1, ICAM1, VCAM1, and CD11b. Image analysis software QuPath was used for quantification of positive leukocytes (PSGL-1 and CD11b) and endothelium (E-selectin, P-selectin, ICAM1, VCAM1). Expression of IL-6 and IL-1ß was quantified by RT-qPCR. Expression of P-selectin and PSGL-1 was strongly increased in the COVID-19 cohort compared with all control groups (COVID-19:Controls, 17:23, P < .0001; COVID-19:Controls, 2:75, P < .0001, respectively). Importantly, P-selectin was found in endothelial cells and associated with aggregates of activated platelets adherent to the endothelial surface in COVID-19 cases. In addition, PSGL-1 staining disclosed positive perivascular leukocyte cuffs, reflecting capillaritis. Moreover, CD11b showed a strongly increased positivity in COVID-19 compared with all controls (COVID-19:Controls, 2:89; P = .0002), indicating a proinflammatory immune microenvironment. Of note, CD11b exhibited distinct staining patterns at different stages of COVID-19 disease. Only in cases with very short disease course, high levels of IL-1ß and IL-6 mRNA were observed in lung tissue. The striking upregulation of PSGL-1 and P-selectin reflects the activation of this receptor-ligand pair in COVID-19, increasing the efficiency of initial leukocyte recruitment, thus promoting tissue damage and immunothrombosis. Our results show that endothelial activation and unbalanced leukocyte migration play a central role in COVID-19 involving the P-selectin-PSGL-1 axis.

Antibody-induced procoagulant platelets in severe COVID-19 infection.

The pathophysiology of COVID-19-associated thrombosis seems to be multifactorial. We hypothesized that COVID-19 is accompanied by procoagulant platelets with subsequent alteration of the coagulation system. We investigated depolarization of mitochondrial inner transmembrane potential (ΔΨm), cytosolic calcium (Ca2+) concentration, and phosphatidylserine (PS) externalization. Platelets from COVID-19 patients in the intensive care unit (ICU; n = 21) showed higher ΔΨm depolarization, cytosolic Ca2+, and PS externalization compared with healthy controls (n = 18) and non-ICU COVID-19 patients (n = 4). Moreover, significant higher cytosolic Ca2+ and PS were observed compared with a septic ICU control group (ICU control; n = 5). In the ICU control group, cytosolic Ca2+ and PS externalization were comparable with healthy controls, with an increase in ΔΨm depolarization. Sera from COVID-19 patients in the ICU induced a significant increase in apoptosis markers (ΔΨm depolarization, cytosolic Ca2+, and PS externalization) compared with healthy volunteers and septic ICU controls. Interestingly, immunoglobulin G fractions from COVID-19 patients induced an Fcγ receptor IIA-dependent platelet apoptosis (ΔΨm depolarization, cytosolic Ca2+, and PS externalization). Enhanced PS externalization in platelets from COVID-19 patients in the ICU was associated with increased sequential organ failure assessment score (r = 0.5635) and D-dimer (r = 0.4473). Most importantly, patients with thrombosis had significantly higher PS externalization compared with those without. The strong correlations between markers for apoptosic and procoagulant platelets and D-dimer levels, as well as the incidence of thrombosis, may indicate that antibody-mediated procoagulant platelets potentially contributes to sustained increased thromboembolic risk in ICU COVID-19 patients.

Membrane oxygenator longevity was higher in argatroban-treated patients undergoing vvECMO.

BACKGROUND: In severe acute respiratory distress syndrome (ARDS), venovenous extracorporeal membrane oxygenation (vvECMO) can be a lifesaver. However, anticoagulation therapy is mandatory because the nonendothelial extracorporeal surface increases the risk of thromboembolic problems. Heparin is still the most common anticoagulant, but argatroban could be an alternative. This work investigates whether argatroban offers a therapeutic advantage over heparin during vvECMO. METHODS: We performed a retrospective cohort study of patients who underwent vvECMO for severe ARDS and received heparin or argatroban as anticoagulation therapy. Demographic variables, intensive care unit (ICU) treatment and outcome parameters were evaluated. The primary outcome parameter was the operating time of the membrane oxygenator normalized to the duration of vvECMO treatment. Secondary outcome parameters were transfusion requirements normalized to the duration of vvECMO therapy. RESULTS: Fifty seven patients from January 2019 to February 2021 underwent vvECMO and were included in this study. Thirty three patients received heparin and 24 patients argatroban as anticoagulatory therapy. The groups did not differ in demographics, ICU scoring systems, or comorbidities. Platelet counts and partial prothrombin time did not differ between the two groups during the first 6 days of vvECMO. The argatroban group had lower requirements for red blood cells, platelets and fresh frozen plasma. The mean runtime of the individual membrane oxygenator increased from 12.3 days (heparin group) to 16.6 days in the argatroban group. CONCLUSIONS: Our findings suggest that argatroban can be considered as anticoagulant during vvECMO.

Early vvECMO implantation may be associated with lower mortality in ARDS.

BACKGROUND: Venovenous extracorporeal membrane oxygenation (vvECMO) is used to treat hypoxia in patients with severe acute respiratory distress syndrome (ARDS). Nevertheless, uncertainty exists regarding the optimal timing of initiation of vvECMO therapy. We aimed to investigate the association between number of days of invasive mechanical ventilation (IMV) prior to vvECMO implantation and mortality. METHODS: In this retrospective observational study, we included patients treated at an academic intensive care unit with vvECMO for severe ARDS. The primary outcome was all-cause 28-day mortality. We conducted a multivariate logistic regression analysis to estimate the association between number of days of IMV prior to vvECMO implantation and mortality after adjustment for confounders. RESULTS: Out of 274 patients who underwent ECMO for severe ARDS, 158 patients (median age: 58 years) with relevant data were included in the analysis. The mean duration of IMV prior to vvECMO was significantly shorter in survivors than in nonsurvivors [survivors median: 1; interquartile range: 1-3; non-survivors median 4; interquartile range: 1-5.75; p = 0.0001). Logistic regression showed an association between the duration of ventilation prior to vvECMO and patient mortality. The odds ratio for the all-cause 28-day mortality and in-hospital mortality was significantly reduced in patients who received vvECMO within the first 5 days of IMV. CONCLUSIONS: Early vvECMO implantation may be associated with lower mortality in ARDS.

Inhaled prostacyclin therapy in the acute respiratory distress syndrome: a randomized controlled multicenter trial.

BACKGROUND: Acute respiratory distress syndrome (ARDS) results in significant hypoxia, and ARDS is the central pathology of COVID-19. Inhaled prostacyclin has been proposed as a therapy for ARDS, but data regarding its role in this syndrome are unavailable. Therefore, we investigated whether inhaled prostacyclin would affect the oxygenation and survival of patients suffering from ARDS. METHODS: We performed a prospective randomized controlled single-blind multicenter trial across Germany. The trial was conducted from March 2019 with final follow-up on 12th of August 2021. Patients with moderate to severe ARDS were included and randomized to receive either inhaled prostacyclin (3 times/day for 5 days) or sodium chloride (Placebo). The primary outcome was the oxygenation index in the intervention and control groups on Day 5 of therapy. Secondary outcomes were mortality, secondary organ failure, disease severity and adverse events. RESULTS: Of 707 patients approached 150 patients were randomized to receive inhaled prostacyclin (n = 73) or sodium chloride (n = 77). Data from 144 patients were analyzed. The baseline PaO2/FiO2 ratio did not differ between groups. The primary analysis of the study was negative, and prostacyclin improved oxygenation by 20 mmHg more than Placebo (p = 0.17). Secondary analysis showed that the oxygenation was significantly improved in patients with ARDS who were COVID-19-positive (34 mmHg, p = 0.04). Mortality did not differ between groups. Secondary organ failure and adverse events were similar in the intervention and control groups. CONCLUSIONS: The primary result of our study was negative. Our data suggest that inhaled prostacyclin might be beneficial treatment in patients with COVID-19 induced ARDS. TRIAL REGISTRATION: The study was approved by the Institutional Review Board of the Research Ethics Committee of the University of Tübingen (899/2018AMG1) and the corresponding ethical review boards of all participating centers. The trial was also approved by the Federal Institute for Drugs and Medical Devices (BfArM, EudraCT No. 2016003168-37) and registered at clinicaltrials.gov (NCT03111212) on April 6th 2017.

COVID-19 does not influence functional status after ARDS therapy.

RATIONALE: Health-related quality of life after surviving acute respiratory distress syndrome has come into focus in recent years, especially during the coronavirus disease 2019 pandemic. OBJECTIVES: A total of 144 patients with acute respiratory distress syndrome caused by COVID-19 or of other origin were recruited in a randomized multicenter trial. METHODS: Clinical data during intensive care treatment and data up to 180 days after study inclusion were collected. Changes in the Sequential Organ Failure Assessment score were used to quantify disease severity. Disability was assessed using the Barthel index on days 1, 28, 90, and 180. MEASUREMENTS: Mortality rate and morbidity after 180 days were compared between patients with and without COVID-19. Independent risk factors associated with high disability were identified using a binary logistic regression. MAIN RESULTS: The SOFA score at day 5 was an independent risk factor for high disability in both groups, and score dynamic within the first 5 days significantly impacted disability in the non-COVID group. Mortality after 180 days and impairment measured by the Barthel index did not differ between patients with and without COVID-19. CONCLUSIONS: Resolution of organ dysfunction within the first 5 days significantly impacts long-term morbidity. Acute respiratory distress syndrome caused by COVID-19 was not associated with increased mortality or morbidity.

Development of an Anticipatory Triage-Ranking Algorithm Using Dynamic Simulation of the Expected Time Course of Patients With Trauma: Modeling and Simulation Study.

BACKGROUND: In cases of terrorism, disasters, or mass casualty incidents, far-reaching life-and-death decisions about prioritizing patients are currently made using triage algorithms that focus solely on the patient's current health status rather than their prognosis, thus leaving a fatal gap of patients who are under- or overtriaged. OBJECTIVE: The aim of this proof-of-concept study is to demonstrate a novel approach for triage that no longer classifies patients into triage categories but ranks their urgency according to the anticipated survival time without intervention. Using this approach, we aim to improve the prioritization of casualties by respecting individual injury patterns and vital signs, survival likelihoods, and the availability of rescue resources. METHODS: We designed a mathematical model that allows dynamic simulation of the time course of a patient's vital parameters, depending on individual baseline vital signs and injury severity. The 2 variables were integrated using the well-established Revised Trauma Score (RTS) and the New Injury Severity Score (NISS). An artificial patient database of unique patients with trauma (N=82,277) was then generated and used for analysis of the time course modeling and triage classification. Comparative performance analysis of different triage algorithms was performed. In addition, we applied a sophisticated, state-of-the-art clustering method using the Gower distance to visualize patient cohorts at risk for mistriage. RESULTS: The proposed triage algorithm realistically modeled the time course of a patient's life, depending on injury severity and current vital parameters. Different casualties were ranked by their anticipated time course, reflecting their priority for treatment. Regarding the identification of patients at risk for mistriage, the model outperformed the Simple Triage And Rapid Treatment's triage algorithm but also exclusive stratification by the RTS or the NISS. Multidimensional analysis separated patients with similar patterns of injuries and vital parameters into clusters with different triage classifications. In this large-scale analysis, our algorithm confirmed the previously mentioned conclusions during simulation and descriptive analysis and underlined the significance of this novel approach to triage. CONCLUSIONS: The findings of this study suggest the feasibility and relevance of our model, which is unique in terms of its ranking system, prognosis outline, and time course anticipation. The proposed triage-ranking algorithm could offer an innovative triage method with a wide range of applications in prehospital, disaster, and emergency medicine, as well as simulation and research.

Uterine allograft removal by total laparoscopic hysterectomy after successful cesarean delivery in a living-donor uterus recipient with uterovaginal agenesis (MRKHS).

PURPOSE: To limit the burden of long-term immunosuppression (IS) after uterus transplantation (UTx), removal of the uterine allograft is indicated after maximum two pregnancies. Hitherto this has required graft hysterectomy by laparotomy. Our objective was to demonstrate, as a proof of concept, the feasibility of less traumatic transplantectomy by total laparoscopic hysterectomy (TLH). PATIENT: A 37-year-old woman with uterovaginal agenesis due to Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) who had undergone neovaginoplasty at age 19 years prior to living-donor (LD) UTx in 10/2019 at age 35 years gave birth to a healthy boy by primary cesarean section in 06/2021. During pregnancy, she developed impaired renal function, with bilateral hydronephrosis, necessitating early allograft removal in 09/2021 to prevent chronic kidney disease, particularly during a potential second pregnancy. METHODS: Transplantectomy by TLH essentially followed standard TLH procedures. We paid meticulous attention to removing as much donor tissue as possible to prevent postoperative complications from residual donor tissue after stopping IS, as well as long-term vascular damage. RESULTS: TLH was performed successfully without the need to convert to open surgery. Surgical time was 90 min with minimal blood loss. No major complications occurred intra- or postoperatively and during the subsequent 9-month follow-up period. Kidney function normalized. CONCLUSIONS: To our knowledge, we report the first successful TLH-based removal of a uterine allograft in a primipara after LD UTx, thus demonstrating the feasibility of TLH in uterus recipients with MRKHS.

Preexisting comorbidities shape the immune response associated with severe COVID-19.

BACKGROUND: Comorbidities are risk factors for development of severe coronavirus disease 2019 (COVID-19). However, the extent to which an underlying comorbidity influences the immune response to severe acute respiratory syndrome coronavirus 2 remains unknown. OBJECTIVE: Our aim was to investigate the complex interrelations of comorbidities, the immune response, and patient outcome in COVID-19. METHODS: We used high-throughput, high-dimensional, single-cell mapping of peripheral blood leukocytes and algorithm-guided analysis. RESULTS: We discovered characteristic immune signatures associated not only with severe COVID-19 but also with the underlying medical condition. Different factors of the metabolic syndrome (obesity, hypertension, and diabetes) affected distinct immune populations, thereby additively increasing the immunodysregulatory effect when present in a single patient. Patients with disorders affecting the lung or heart, together with factors of metabolic syndrome, were clustered together, whereas immune disorder and chronic kidney disease displayed a distinct immune profile in COVID-19. In particular, severe acute respiratory syndrome coronavirus 2-infected patients with preexisting chronic kidney disease were characterized by the highest number of altered immune signatures of both lymphoid and myeloid immune branches. This overall major immune dysregulation could be the underlying mechanism for the estimated odds ratio of 16.3 for development of severe COVID-19 in this burdened cohort. CONCLUSION: The combinatorial systematic analysis of the immune signatures, comorbidities, and outcomes of patients with COVID-19 has provided the mechanistic immunologic underpinnings of comorbidity-driven patient risk and uncovered comorbidity-driven immune signatures.

Intravenous IgM-enriched immunoglobulins in critical COVID-19: a multicentre propensity-weighted cohort study.

BACKGROUND: A profound inflammation-mediated lung injury with long-term acute respiratory distress and high mortality is one of the major complications of critical COVID-19. Immunoglobulin M (IgM)-enriched immunoglobulins seem especially capable of mitigating the inflicted inflammatory harm. However, the efficacy of intravenous IgM-enriched preparations in critically ill patients with COVID-19 is largely unclear. METHODS: In this retrospective multicentric cohort study, 316 patients with laboratory-confirmed critical COVID-19 were treated in ten German and Austrian ICUs between May 2020 and April 2021. The primary outcome was 30-day mortality. Analysis was performed by Cox regression models. Covariate adjustment was performed by propensity score weighting using machine learning-based SuperLearner to overcome the selection bias due to missing randomization. In addition, a subgroup analysis focusing on different treatment regimens and patient characteristics was performed. RESULTS: Of the 316 ICU patients, 146 received IgM-enriched immunoglobulins and 170 cases did not, which served as controls. There was no survival difference between the two groups in terms of mortality at 30 days in the overall cohort (HRadj: 0.83; 95% CI: 0.55 to 1.25; p = 0.374). An improved 30-day survival in patients without mechanical ventilation at the time of the immunoglobulin treatment did not reach statistical significance (HRadj: 0.23; 95% CI: 0.05 to 1.08; p = 0.063). Also, no statistically significant difference was observed in the subgroup when a daily dose of ≥ 15 g and a duration of ≥ 3 days of IgM-enriched immunoglobulins were applied (HRadj: 0.65; 95% CI: 0.41 to 1.03; p = 0.068). CONCLUSIONS: Although we cannot prove a statistically reliable effect of intravenous IgM-enriched immunoglobulins, the confidence intervals may suggest a clinically relevant effect in certain subgroups. Here, an early administration (i.e. in critically ill but not yet mechanically ventilated COVID-19 patients) and a dose of ≥ 15 g for at least 3 days may confer beneficial effects without concerning safety issues. However, these findings need to be validated in upcoming randomized clinical trials. Trial registration DRKS00025794 , German Clinical Trials Register, https://www.drks.de . Registered 6 July 2021.

Key characteristics impacting survival of COVID-19 extracorporeal membrane oxygenation.

BACKGROUND: Severe COVID-19 induced acute respiratory distress syndrome (ARDS) often requires extracorporeal membrane oxygenation (ECMO). Recent German health insurance data revealed low ICU survival rates. Patient characteristics and experience of the ECMO center may determine intensive care unit (ICU) survival. The current study aimed to identify factors affecting ICU survival of COVID-19 ECMO patients. METHODS: 673 COVID-19 ARDS ECMO patients treated in 26 centers between January 1st 2020 and March 22nd 2021 were included. Data on clinical characteristics, adjunct therapies, complications, and outcome were documented. Block wise logistic regression analysis was applied to identify variables associated with ICU-survival. RESULTS: Most patients were between 50 and 70 years of age. PaO2/FiO2 ratio prior to ECMO was 72 mmHg (IQR: 58-99). ICU survival was 31.4%. Survival was significantly lower during the 2nd wave of the COVID-19 pandemic. A subgroup of 284 (42%) patients fulfilling modified EOLIA criteria had a higher survival (38%) (p = 0.0014, OR 0.64 (CI 0.41-0.99)). Survival differed between low, intermediate, and high-volume centers with 20%, 30%, and 38%, respectively (p = 0.0024). Treatment in high volume centers resulted in an odds ratio of 0.55 (CI 0.28-1.02) compared to low volume centers. Additional factors associated with survival were younger age, shorter time between intubation and ECMO initiation, BMI > 35 (compared to < 25), absence of renal replacement therapy or major bleeding/thromboembolic events. CONCLUSIONS: Structural and patient-related factors, including age, comorbidities and ECMO case volume, determined the survival of COVID-19 ECMO. These factors combined with a more liberal ECMO indication during the 2nd wave may explain the reasonably overall low survival rate. Careful selection of patients and treatment in high volume ECMO centers was associated with higher odds of ICU survival. TRIAL REGISTRATION: Registered in the German Clinical Trials Register (study ID: DRKS00022964, retrospectively registered, September 7th 2020, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00022964 .

Left ventricular assist device implantation causes platelet dysfunction and proinflammatory platelet-neutrophil interaction.

Blood flow through left ventricular assist devices (LVAD) may induce activation and dysfunction of platelets. Dysfunctional platelets cause coagulation disturbances and form platelet-neutrophil conjugates (PNC), which contribute to inflammatory tissue damage. This prospective observational cohort study investigated patients, who underwent implantation of a LVAD (either HeartMate II (HM II) (n = 7) or HeartMate 3 (HM 3) (n = 6)) and as control patients undergoing coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR) (n = 10). We performed platelet and leukocyte flow cytometry, analysis of platelet activation markers, and platelet aggregometry. Platelet CD42b expression was reduced at baseline and perioperatively in HM II/3 compared to CABG/AVR patients. After surgery the platelet activation marker ß-thromboglobulin and platelet microparticles increased in all groups while platelet aggregation decreased. Platelet aggregation was more significantly impaired in LVAD compared to CABG/AVR patients. PNC were higher in HM II compared to HM 3 patients. We conclude that LVAD implantation is associated with platelet dysfunction and proinflammatory platelet-leukocyte binding. These changes are less pronounced in patients treated with the newer generation LVAD HM 3. Future research should identify device-specific LVAD features, which are associated with the least amount of platelet activation to further improve LVAD therapy.

A comparison of first-attempt cannulation success of peripheral venous catheter systems with and without wings and injection ports in surgical patients-a randomized trial.

BACKGROUND: A peripheral venous catheter (PVC) is the most widely used device for obtaining vascular access, allowing the administration of fluids and medication. Up to 25% of adult patients, and 50% of pediatric patients experience a first-attempt cannulation failure. In addition to patient and clinician characteristics, device features might affect the handling and success rates. The objective of the study was to compare the first-attempt cannulation success rate between PVCs with wings and a port access (Vasofix® Safety, B. Braun, abbreviated hereon in as VS) with those without (Introcan® Safety, B. Braun, abbreviated hereon in as IS) in an anesthesiological cohort. METHODS: An open label, multi-center, randomized trial was performed. First-attempt cannulation success rates were examined, along with relevant patient, clinician, and device characteristics with univariate and multivariate analyses. Information on handling and adherence to use instructions was gathered, and available catheters were assessed for damage. RESULTS: Two thousand three hundred four patients were included in the intention to treat analysis. First-attempt success rate was significantly higher with winged and ported catheters (VS) than with the non-winged, non-ported design (IS) (87.5% with VS vs. 78.2% with IS; PChi < .001). Operators rated the handling of VS as superior (rating of "good" or "very good: 86.1% VS vs. 20.8% IS, PChi < .001). Reinsertion of the needle into the catheter after partial withdrawal-prior or during the catheterization attempt-was associated with an increased risk of cannulation failure (7.909, CI 5.989-10.443, P < .001 and 23.023, CI 10.372-51.105, P < .001, respectively) and a twofold risk of catheter damage (OR 1.999, CI 1.347-2.967, P = .001). CONCLUSIONS: First-attempt cannulation success of peripheral, ported, winged catheters was higher compared to non-ported, non-winged devices. The handling of the winged and ported design was better rated by the clinicians. Needle reinsertions are related to an increase in rates of catheter damage and cannulation failure. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT02213965 , Date: 12/08/2014.

A one-day focused cardiac ultrasound training has a limited impact on residents' abilities to visually assess right ventricular dimensions and function.

BACKGROUND: Focused cardiac ultrasound (FCU) is a helpful tool to rapidly identify right ventricular (RV) causes of hemodynamic instability and facilitate the initiation of therapy. The clinical value of existing course models often remains unclear. This study investigated the effects of a one-day FCU training on the visual estimation skills of RV characteristics. METHODS: Four residents were included as the study group after completing a standardized one-day FCU training. Four gender-matched controls did not take part in the training. All residents graded image quality, RV systolic function, and RV dimensions in a test comprising 35 ultrasound clips. RESULTS: The study and control group did not differ in ICU or ultrasound experience. Overall, training participants were able to distinguish between good and insufficient image quality significantly better than the control group (agreement 80.0% vs 61.4%, p = 0.04). The agreement for the estimation of RV function and RV dimensions was not different between the groups (63.2% vs 60.5%, p = 0.66 and 64.3% vs 67.1%, p = 0.18, respectively). Descriptively, only small differences were found between the groups for the estimation of RV function and RV dimensions in subgroups of patients with normal versus reduced systolic RV function or normal versus enlarged RV dimensions, respectively. Both groups struggled in identifying RV enlargement (34.6% vs 46.2%). DISCUSSION: In this study, a single one-day FCU training had no impact on residents' skills to visually assess systolic RV function or RV dimensions. Improvements of current training modalities or continuous teaching models are needed to optimize residency programs and patient care.