Diagnostic yield of routine daily blood culture in patients on veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: Bloodstream infections (BSIs) are frequent on veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Performing routine blood cultures (BCs) may identify early paucisymptomatic BSIs. We investigated the contribution of systematic daily BCs to detect BSIs on V-A ECMO. METHODS: This was a retrospective study including all adult patients requiring V-A ECMO and surviving more than 24 h. Our protocol included routine daily BCs, from V-A ECMO insertion up to 5 days after withdrawal; other BCs were performed on-demand. RESULTS: On the 150 V-A ECMO included, 2146 BCs were performed (1162 routine and 984 on-demand BCs); 190 (9%) were positive, including 68 contaminants. Fifty-one (4%) routine BCs revealed BSIs; meanwhile, 71 (7%) on-demand BCs revealed BSIs (p = 0.005). Performing routine BCs was negatively associated with BSIs diagnosis (OR 0.55, 95% CI [0.38; 0.81], p = 0.002). However, 16 (31%) BSIs diagnosed by routine BCs would have been missed by on-demand BCs. Independent variables for BSIs diagnosis after routine BCs were: V-A ECMO for cardiac graft failure (OR 2.43, 95% CI [1.20; 4.92], p = 0.013) and sampling with on-going antimicrobial therapy (OR 2.15, 95% CI [1.08; 4.27], p = 0.029) or renal replacement therapy (OR 2.05, 95% CI [1.10; 3.81], p = 0.008). Without these three conditions, only two BSIs diagnosed with routine BCs would have been missed by on-demand BCs sampling. CONCLUSIONS: Although routine daily BCs are less effective than on-demand BCs and expose to contamination and inappropriate antimicrobial therapy, a policy restricted to on-demand BCs would omit a significant proportion of BSIs. This argues for a tailored approach to routine daily BCs on V-A ECMO, based on risk factors for positivity.

Clinical practice recommendations on the management of perioperative cardiac arrest: A report from the PERIOPCA Consortium.

BACKGROUND: Perioperative cardiac arrest is a rare complication with an incidence of around 1 in 1400 cases, but it carries a high burden of mortality reaching up to 70% at 30 days. Despite its specificities, guidelines for treatment of perioperative cardiac arrest are lacking. Gathering the available literature may improve quality of care and outcome of patients. METHODS: The PERIOPCA Task Force identified major clinical questions about the management of perioperative cardiac arrest and framed them into the therapy population [P], intervention [I], comparator [C], and outcome [O] (PICO) format. Systematic searches of PubMed, Embase, and the Cochrane Library for articles published until September 2020 were performed. Consensus-based treatment recommendations were created using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. The strength of consensus among the Task Force members about the recommendations was assessed through a modified Delphi consensus process. RESULTS: Twenty-two PICO questions were addressed, and the recommendations were validated in two Delphi rounds. A summary of evidence for each outcome is reported and accompanied by an overall assessment of the evidence to guide healthcare providers. CONCLUSIONS: The main limitations of our work lie in the scarcity of good quality evidence on this topic. Still, these recommendations provide a basis for decision making, as well as a guide for future research on perioperative cardiac arrest.

Argon Attenuates Multiorgan Failure in Relation with HMGB1 Inhibition.

Argon inhalation attenuates multiorgan failure (MOF) after experimental ischemic injury. We hypothesized that this protection could involve decreased High Mobility Group Box 1 (HMGB1) systemic release. We investigated this issue in an animal model of MOF induced by aortic cross-clamping. Anesthetized rabbits were submitted to supra-coeliac aortic cross-clamping for 30 min, followed by 300 min of reperfusion. They were randomly divided into three groups (n = 7/group). The Control group inhaled nitrogen (70%) and oxygen (30%). The Argon group was exposed to a mixture of argon (70%) and oxygen (30%). The last group inhaled nitrogen/oxygen (70/30%) with an administration of the HMGB1 inhibitor glycyrrhizin (4 mg/kg i.v.) 5 min before aortic unclamping. At the end of follow-up, cardiac output was significantly higher in Argon and Glycyrrhizin vs. Control (60 ± 4 and 49 ± 4 vs. 33 ± 8 mL/kg/min, respectively). Metabolic acidosis was attenuated in Argon and Glycyrrhizin vs. Control, along with reduced amount of norepinephrine to reverse arterial hypotension. This was associated with reduced interleukin-6 and HMGB1 plasma concentration in Argon and Glycyrrhizin vs. Control. End-organ damages were also attenuated in the liver and kidney in Argon and Glycyrrhizin vs. Control, respectively. Argon inhalation reduced HMGB1 blood level after experimental aortic cross-clamping and provided similar benefits to direct HMGB1 inhibition.

Pharmacological targeting of apelin impairs glioblastoma growth.

Glioblastoma are highly aggressive brain tumours that are associated with an extremely poor prognosis. Within these tumours exists a subpopulation of highly plastic self-renewing cancer cells that retain the ability to expand ex vivo as tumourspheres, induce tumour growth in mice, and have been implicated in radio- and chemo-resistance. Although their identity and fate are regulated by external cues emanating from endothelial cells, the nature of such signals remains unknown. Here, we used a mass spectrometry proteomic approach to characterize the factors released by brain endothelial cells. We report the identification of the vasoactive peptide apelin as a central regulator for endothelial-mediated maintenance of glioblastoma patient-derived cells with stem-like properties. Genetic and pharmacological targeting of apelin cognate receptor abrogates apelin- and endothelial-mediated expansion of glioblastoma patient-derived cells with stem-like properties in vitro and suppresses tumour growth in vivo. Functionally, selective competitive antagonists of apelin receptor were shown to be safe and effective in reducing tumour expansion and lengthening the survival of intracranially xenografted mice. Therefore, the apelin/apelin receptor signalling nexus may operate as a paracrine signal that sustains tumour cell expansion and progression, suggesting that apelin is a druggable factor in glioblastoma.

Hypnosis during Endovascular Abdominal Aortic Aneurysm Repair.

(1) Background: Endovascular abdominal aneurysm repair (EVAR) is associated with a reduction in early morbidity and mortality compared with open repair. Procedures performed under hypnosis might represent an alternative to further reduce the risks related to general anesthesia (GA). This study aimed to assess the feasibility and safety of hypnosis and local anesthesia during EVAR. (2) Methods: All consecutive patients who underwent EVAR or fenestrated/branched EVAR (f/bEVAR) under hypnosis and local anesthesia (n = 28) between 2017 and 2019 were retrospectively studied and matched to control patients who underwent the same interventions under GA. (3) Results: There was neither a significant difference in the length of ICU stay (p = 0.06), nor in the occurrence of endoleaks, reintervention, and 30-day mortality rate (p = 1.00, 0.73, and 0.24, respectively). The hypnosis group had lower use of norepinephrine (maximum dose 0.04 ± 0.1 vs. 1.2 ± 4.0 mg·h-1, p < 0.001), shorter procedure duration (181.2 ± 71.4 vs. 214.3 ± 79.6 h, p = 0.04), and shorter length of stay (5.4 ± 3.2 vs. 8.4 ± 5.9 days, p = 0.002). (4) Conclusions: In this pioneering study, hypnosis during EVAR appears feasible and safe. It is associated with lower intraoperative use of norepinephrine, as well as procedure duration and length of in-hospital stay.

The impact of extracorporeal membrane oxygenation on antifungal pharmacokinetics: A systematic review.

BACKGROUND AND OBJECTIVE: The use of extracorporeal membrane oxygenation (ECMO) as a cardiocirculatory or respiratory support has tremendously increased in critically ill patients. In the setting of ECMO support, invasive fungal infections are a severe cause of morbidity and mortality. This vulnerable population is at risk of suboptimal antifungal exposure due to an increased volume of distribution (Vd), drug sequestration and decreased clearance. Here, we aimed to summarize ex-vivo and clinical studies on the potential impact of ECMO on the pharmacokinetics (PK) of antifungal agents and dosing requirements. METHODS: A systematic search of the literature within electronic databases PubMed and EMBASE was conducted from database inception to 30 April 2023. Inclusion criteria were as follows: critically ill patients receiving ECMO regardless of age and reporting at least one PK parameter. RESULTS: Thirty-six studies met inclusion criteria, including seven ex-vivo experiments and 29 clinical studies evaluating three classes of antifungals: polyenes, triazoles and echinocandins. Based on the available ex-vivo PK data, we found a significant sequestration of highly lipophilic and protein-bound antifungals within the ECMO circuit such as voriconazole, posaconazole and micafungin but the PK of several antifungals remains to be addressed such as amphotericin B, isavuconazole and anidulafungin. Most clinical studies have shown increased Vd of some antifungals like fluconazole and micafungin, particularly in the pediatric population. Conflicting data exist about caspofungin exposure. CONCLUSIONS: The available literature on the antifungal PK changes in ECMO setting is scarce. Whenever possible, therapeutic drug monitoring is highly advised to personalize antifungal therapy.

Identification and validation of extracellular vesicle reference genes for the normalization of RT-qPCR data.

Extracellular vesicles (EVs) contain a plethora of biomolecules, including nucleic acids, with diverse diagnostic and therapeutic application potential. Although reverse transcription-quantitative PCR (RT-qPCR) is the most widely applied laboratory technique to evaluate gene expression, its applicability in EV research is challenged by the lack of universal and stably present reference genes (RGs). In this study, we identify, validate and establish SNRPG, OST4, TOMM7 and NOP10 as RGs for the normalization of EV-associated genes by RT-qPCR. We show the stable presence of SNRPG, OST4, TOMM7 and NOP10 in multiple cell lines and their secreted EVs (n = 12) under different (patho)physiological conditions as well as in human-derived biofluids (n = 3). Enzymatic treatments confirm the presence of SNRPG, OST4, TOMM7 and NOP10 inside EVs. In addition, the four EV-associated RGs are stably detected in a size-range of EV subpopulations. RefFinder analysis reveals that SNRPG, OST4, TOMM7 and NOP10 are more stable compared to RGs established specifically for cultured cells or tissues such as HMBS, YWHAZ, SDHA and GAPDH. In summary, we present four universal and stably present EV-associated RGs to enable normalization and thus steer the implementation of RT-qPCR for the analysis of EV-associated RNA cargo for research or clinical applications.

Upper gastrointestinal bleeding on veno-arterial extracorporeal membrane oxygenation support.

INTRODUCTION: Patients on veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support are at a high risk of hemorrhagic complications, including upper gastrointestinal bleeding (UGIB). The objective of this study was to evaluate the incidence and impact of this complication in V-A ECMO patients. MATERIALS AND METHODS: A retrospective single-center study (2013-2017) was conducted on V-A ECMO patients, excluding those who died within 24 h. All patients with suspected UGIB underwent esophagogastroduodenoscopy (EGD) and were analyzed and compared to the remainder of the cohort, from the initiation of ECMO until 5 days after explantation. RESULTS: A total of 150 V-A ECMO cases (65 after cardiac surgery and 85 due to medical etiology) were included. 90% of the patients received prophylactic proton pump inhibitor therapy and enteral nutrition. Thirty-one patients underwent EGD for suspected UGIB, with 16 confirmed cases of UGIB. The incidence was 10.7%, with a median occurrence at 10 [7-17] days. There were no significant differences in clinical or biological characteristics on the day of EGD. However, patients with UGIB had significant increases in packed red blood cells and fresh frozen plasma needs, mechanical ventilation duration and V-A ECMO duration, as well as in length of intensive care unit and hospital stays. There was no significant difference in mortality. The only independent risk factor of UGIB was a history of peptic ulcer (OR = 7.32; 95% CI [1.07-50.01], p = 0.042). CONCLUSION: UGIB occurred in at least 1 out of 10 cases of V-A ECMO patients, with significant consequences on healthcare resources. Enteral nutrition and proton pump inhibitor prophylaxis did not appear to protect V-A ECMO patients. Further studies should assess their real benefits in these patients with high risk of hemorrhage.

Density-Based Fractionation of Cell-Conditioned Medium to Prepare Proteomics Grade Extracellular Vesicles.

The identification of the molecular composition of extracellular vesicles (EV) by omics approaches, including proteomics, requires the separation of EV from non-EV confounding factors present in the source biofluid. In this protocol, we present the sequential implementation of density gradient ultracentrifugation and size-exclusion chromatography to prepare EV from cell-conditioned medium with high specificity and repeatability. This approach enables the recovery of intact purified EV suited for downstream functional assays and biomarker discovery by omics approaches.

Isolating plasma extracellular vesicles from mouse blood using size-exclusion chromatography, density gradient, and ultracentrifugation.

Circulating extracellular vesicles (EVs) could serve for the surveillance of diverse pathological conditions. We present a protocol for enriching and isolating plasma EVs from mouse blood. We describe steps for employing ultracentrifugation, size-exclusion chromatography, and density gradients, required for further quantitative and qualitative analysis. We detail the procedure for retrieving optimal volume of blood while preserving its integrity and avoiding hemolysis. We also describe the preparation of EVs from this complex fluid containing soluble proteins, aggregates, and lipoprotein particles. For complete details on the use and execution of this protocol, please refer to André-Grégoire et al. (2022).1.

Depletion of soluble cytokines unlocks the immunomodulatory bioactivity of extracellular vesicles.

Despite an enormous interest in understanding the bioactivity of extracellular vesicles (EV) in physiology and disease for the development of therapeutic applications, the impact of EV preparation methods remains minimally explored. In this study, we implemented density gradient ultracentrifugation combined with size-exclusion chromatography (DG-SEC), differential ultracentrifugation (dUC) and/or stand-alone SEC (sSEC) to fractionate media conditioned by different cancer cells and/or cancer-associated fibroblasts (CAF). EV-enriched but protein-depleted versus EV-depleted but protein-enriched DG-SEC fractions, and EV-containing dUC and sSEC preparations were quality controlled for particle number, protein concentration, selected protein composition and ultrastructure, characterized for their cytokine content, and dose-dependently evaluated for monocyte-derived dendritic cell (MoDC) maturation by measuring surface marker expression and/or cytokine secretion. EV preparations obtained by DG-SEC from media conditioned by different cancer cell lines or CAF, were depleted from soluble immune suppressive cytokines such as VEGF-A and MCP-1 and potently stimulated MoDC maturation. In contrast, EV-containing dUC or sSEC preparations were not depleted from these soluble cytokines and were unable to mature MoDC. Subsequent processing of dUC EV preparations by SEC dose-dependently restored the immunomodulatory bioactivity. Overall, our results demonstrate that method-dependent off-target enrichment of soluble cytokines has implications for the study of EV immunomodulatory bioactivity and warrants careful consideration.

The Relative Contributions of Occupational and Community Risk Factors for COVID-19 among Hospital Workers: The HOP-COVID Cohort Study.

The relative contributions of occupational and community sources of COVID-19 among health-care workers (HCWs) are still subject to debate. In a cohort study at a 2814-bed tertiary medical center (five hospitals) in the Paris area of France, we assessed the proportion of hospital-acquired cases among staff and identified risk factors. Between May 2020 and June 2021, HCWs were invited to complete a questionnaire on their COVID-19 risk factors. RT-PCR and serology test results were retrieved from the virology department. Mixed-effects logistic regression was used to account for clustering by hospital. The prevalence of COVID-19 was 15.6% (n = 213/1369 respondents) overall, 29.7% in the geriatric hospitals, and 56.8% of the infections were hospital-acquired. On multivariable analyses adjusted for COVID-19 incidence and contact in the community, a significantly higher risk was identified for staff providing patient care (especially nursing assistants), staff from radiology/functional assessment units and stretcher services, and staff working on wards with COVID-19 clusters among patients or HCWs. The likelihood of infection was greater in geriatric wards than in intensive care units. The presence of significant occupational risk factors after adjustment for community exposure is suggestive of a high in-hospital risk and emphasizes the need for stronger preventive measures-especially in geriatric settings. Clinicaltrials.gov NCT04386759.

Long-Term Results of Endoscopic Metal Stenting for Biliary Anastomotic Stricture after Liver Transplantation.

(1) Background: Anastomotic biliary stricture (ABS) is a well-known complication of liver transplantation which can lead to secondary biliary cirrhosis and graft dysfunction. The goal of this study was to evaluate the long-term outcomes of endoscopic metal stenting of ABS in the setting of deceased donor liver transplantation (DDLT). (2) Methods: Consecutive DDLT patients with endoscopic metal stenting for ABS between 2010 and 2015 were screened. Data on diagnosis, treatment and follow-up (until June 2022) were collected. The primary outcome was endoscopic treatment failure defined as the need for surgical refection. (3) Results: Among the 465 patients who underwent LT, 41 developed ABS. It was diagnosed after a mean period of 7.4 months (+/-10.6) following LT. Endoscopic treatment was technically successful in 95.1% of cases. The mean duration of endoscopic treatment was 12.8 months (+/-9.1) and 53.7% of patients completed a 1-year treatment. After a mean follow-up of 6.9 years (+/-2.3), endoscopic treatment failed in nine patients (22%) who required surgical refection. Conclusions: Endoscopic management with metal stenting of ABS after DDLT was technically successful in most cases, and half of the patients had at least one year of indwelling stent. Endoscopic treatment long-term failure rate occurred in one fifth of the patients.

Population Pharmacokinetics of Amikacin in Patients on Veno-Arterial Extracorporeal Membrane Oxygenation.

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support leads to complex pharmacokinetic alterations, whereas adequate drug dosing is paramount for efficacy and absence of toxicity in critically ill patients. Amikacin is a major antibiotic used in nosocomial sepsis, especially for these patients. We aimed to describe amikacin pharmacokinetics on V-A ECMO support and to determine relevant variables to improve its dosing. All critically ill patients requiring empirical antimicrobial therapy, including amikacin for nosocomial sepsis supported or not by V-A ECMO, were included in a prospective population pharmacokinetic study. This population pharmacokinetic analysis was built with a dedicated software, and Monte Carlo simulations were performed to identify doses achieving therapeutic plasma concentrations. Thirty-nine patients were included (control n = 15, V-A ECMO n = 24); 215 plasma assays were performed and used for the modeling process. Patients received 29 (24-33) and 32 (30-35) mg/kg of amikacin in control and ECMO groups, respectively. Data were best described by a two-compartment model with first-order elimination. Inter-individual variabilities were observed on clearance, central compartment volume (V1), and peripherical compartment volume (V2). Three significant covariates explained these variabilities: Kidney Disease Improving Global Outcomes (KDIGO) stage on amikacin clearance, total body weight on V1, and ECMO support on V2. Our simulations showed that the adequate dosage of amikacin was 40 mg/kg in KDIGO stage 0 patients, while 25 mg/kg in KDIGO stage 3 patients was relevant. V-A ECMO support had only a secondary impact on amikacin pharmacokinetics, as compared to acute kidney injury.

Percutaneous angio-guided versus surgical veno-arterial ECLS implantation in patients with cardiogenic shock or cardiac arrest.

BACKGROUND: Veno-arterial Extracorporeal Life Support (V-A ECLS) has gained increasing place into the management of patients with refractory cardiogenic shock or cardiac arrest. Both surgical and percutaneous approach can be used for cannulation, but percutaneous approach has been associated with fewer complications. Angio-guided percutaneous cannulation and decannulation may further decrease the rate of complication. We aimed to compare outcome and complication rates in patients supported with V-A ECLS through percutaneous angio-guided versus surgical approach. METHODS: We included all patients with emergent peripheral femoro-femoral V-A ECLS implantation for refractory cardiogenic shock or cardiac arrest in our center from March 2018 to March 2021. Survival and major complications (major bleeding, limb ischemia and groin infection) rates were compared between the percutaneous angio-guided and the surgical groups. RESULTS: One hundred twenty patients received V-A ECLS, 59 through surgical approach and 61 through angio-guided percutaneous approach. Patients' baseline characteristics and severity scores were equally balanced between the 2 groups. Thirty-day mortality was not significantly different between the 2 approaches. However, angio-guided percutaneous cannulation was associated with fewer major vascular complications (42% vs. 11%, p > 0.0001) and a higher rate of V-A ECLS decannulation. In multivariate analysis, percutaneous angio-guided implantation of V-A ECLS was independently associated with a lower probability of major complications. CONCLUSION: Compared to surgical approach, angio-guided percutaneous V-A ECLS implantation is associated with fewer major vascular complications. Larger studies are needed to confirm those results and address their impact on mortality.