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Common causes of poorly controlled asthma include nonadherence to long-term inhaler therapy; environmental exposures; and uncontrolled comorbidities, such as allergic rhinitis. Adherence can be limited by many factors, including inadequate patient education, medication cost, prior failed treatment, poor physician-patient relationship, unrealistic expectations for therapy, and depression. For patients who have a poor perception of their symptoms, emphasizing the 'disconnect' between symptoms and pulmonary function can help motivate them to monitor themselves with a peak flow me-ter and to adjust their medication accordingly. For patients with allergic triggers, instituting allergen-specific environmental controls can decrease symptoms and urgent care visits for asthma. Chronic rhinosinusitis and gastroesophageal reflux disease can also contribute to difficult-to-control asthma, and treatment of these comorbidities can help reduce asthma symptoms. [ABSTRACT FROM AUTHOR]

Difficult-to-control asthma requires a systematic and thorough evaluation, first to confirm the diagnosis of asthma, and then to identify the contributing factors. The causes of poor asthma control include inadequate therapy; nonadherence to therapy; persistent environmental triggers; and aggravating co-morbid conditions, such as allergic rhinitis, chronic rhino-sinusitis, and gastroesophageal reflux disease. To distinguish asthma from other common causes of episodic dyspnea, such as heart disease, upper airway obstruction, and other lung diseases, all patients should undergo spirometry. Other useful tools include methacholine provocation, peak expiratory flow monitoring, cardiopulmonary exercise testing, chest radiography, measurement of carbon monoxide--diffusing capacity, and direct laryngoscopy. With a careful clinical evaluation and selective testing, asthma control can be improved and exacerbations reduced in most patients. [ABSTRACT FROM AUTHOR]

Epithelial cells provide a first line of immune defense by maintaining barrier function, orchestrating mucociliary clearance, secreting antimicrobial molecules, and generating sentinel signals to both activate innate immune cells and shape adaptive immunity. Although epithelial alarmins play a particularly important role in the initiation of type 2 inflammation in response to allergens, the mechanisms by which epithelial cells sense the environment and regulate the generation and release of alarmins have been poorly understood. Recent studies have identified new sensors and signaling pathways used by barrier epithelial cells to elicit type 2 inflammation, including a novel pathway for the release of interleukin-33 from the nucleus that depends on apoptotic signaling. These recent findings have implications in the development of allergic diseases, from atopic eczema to food allergy, rhinitis, and asthma., Competing Interests: Declaration of Competing Interest Michael Mandanas and Nora A Barrett have no interests to declare., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The cysteinyl leukotrienes (CysLTs), LTC 4 , LTD 4 , and LTE 4 , are potent lipid mediators derived from arachidonic acid through the 5-lipoxygenase pathway. These mediators produce both inflammation and bronchoconstriction through three distinct G protein-coupled receptors (GPCRs)-CysLT 1 , CysLT 2 , and OXGR1 (also known as CysLT 3 or GPR99). While CysLT-mediated functions in the effector phase of allergic inflammation and asthma have been established for some time, recent work has demonstrated novel roles for these mediators and their receptors in the induction and amplification of type 2 inflammation. Additionally, in vitro studies and murine models have uncovered diverse regulatory mechanisms that restrain or amplify CysLT receptor activation and CysLT receptor function. This review provides an overview of CysLT biosynthesis and its regulation, the molecular and functional pharmacology of CysLT receptors, and an overview of the established and emerging roles of CysLTs in asthma, aspirin-exacerbated respiratory disease, and type 2 inflammation.

Asthma is a complex disease caused by genetic and environmental factors. Studies show that wheezing during rhinovirus infection correlates with childhood asthma development. Over 150 non-coding risk variants for asthma have been identified, many affecting gene regulation in T cells, but the effects of most risk variants remain unknown. We hypothesized that airway epithelial cells could also mediate genetic susceptibility to asthma given they are the first line of defense against respiratory viruses and allergens. We integrated genetic data with transcriptomics of airway epithelial cells subject to different stimuli. We demonstrate that rhinovirus infection significantly upregulates childhood-onset asthma-associated genes, particularly in non-ciliated cells. This enrichment is also observed with influenza infection but not with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or cytokine activation. Overall, our results suggest that rhinovirus infection is an environmental factor that interacts with genetic risk factors through non-ciliated airway epithelial cells to drive childhood-onset asthma., Competing Interests: Declaration of interests J.A.B. has served on scientific advisory boards for Siolta Therapeutics, Third Harmonic Bio, and Sanofi/Aventis. N.A.B. has served on scientific advisory boards for Regeneron., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Extracorporeal carbon dioxide removal (ECCO2R) devices are increasingly used in treating acute-on-chronic respiratory failure caused by chronic lung diseases. There are no large studies that investigated safety, efficacy, and the independent association of prognostic variables to survival that could define the role of ECCO2R devices in such patients. This multicenter, multinational, retrospective study investigated the efficacy, safety of a single ECCO2R device (Hemolung) in patients with acute on chronic respiratory failure and identified variables independently associated with intensive care unit (ICU) survival. The primary outcome was improvement in blood gasses with the use of Hemolung. Secondary outcomes included reduction in tidal volume, respiratory rate, minute ventilation, survival to ICU discharge, and complication profile. Multivariable regression analysis was used to identify variables that are independently associated with ICU survival. A total of 62 patients were included. There was a significant improvement in pH and partial pressure of carbon dioxide in arterial blood (PaCO2) along with a reduction in respiratory rate, tidal volume, and minute ventilation with Hemolung therapy. The complication profile did not differ between survivors and nonsurvivors. Multivariable analysis identified the duration of Hemolung therapy to be independently associated with survival to ICU discharge (adjusted odds ratio = 1.21; 95% confidence interval [CI] = 1.040-1.518; p = 0.01)., Competing Interests: Disclosure: A.M. is an employee of ALung Technologies, Inc. B.A., and S.A.C. received consulting fees from ALung Technologies, Inc. NB’s institution received fee from ALung Technologies, Inc. R.T. has no direct conflicts of interest with this manuscript, but has received speaking fee from Baxter Healthcare, unrelated to this study. K.D. has no conflicts to declare., (Copyright © ASAIO 2024.)

Background: Lung function is an independent predictor of mortality. We evaluated the lung function trajectories of a cohort of patients with asthma receiving biologic therapy., Methods: We identified 229 monoclonal antibody-naïve adult patients with moderate-to-severe asthma who initiated omalizumab, mepolizumab, or dupilumab between 2010 and 2022 in a large healthcare system in Boston, MA. Generalized additive mixed models were used to estimate the lung function trajectories during the 156 weeks following biologic initiation. Response was defined as an improvement in FEV 1 or a decrease of ≤0.5% per year. The Kaplan-Meier estimator was used to assess time to no additional improvement in FEV 1 in responders. All models were adjusted for age, sex, body mass index, smoking status, baseline exacerbation rate, and baseline blood eosinophil count., Results: Eighty-eight patients initiated mepolizumab, 76 omalizumab, and 65 dupilumab. Baseline eosinophil count was highest in the mepolizumab group (405 cells/mcL) and lowest for omalizumab (250 cells/mcL). Both FEV 1 and FVC improved in the mepolizumab group (FEV 1  + 20 mL/year; FVC +43 mL/year). For omalizumab, there was an initial improvement in the first year followed by decline with an overall FEV 1 loss of -44 mL/year and FVC -32 mL/year. For dupilumab, both FEV 1 (+61 mL/year) and FVC (+74 mL/year) improved over time. Fifty percent of the mepolizumab group, 58% omalizumab, and 72% of dupilumab were responders. The median time to no additional FEV 1 improvement in responders was 24 weeks for omalizumab, 48 weeks for mepolizumab, and 57 weeks for dupilumab., Conclusion: In this clinical cohort, mepolizumab, omalizumab, and dupilumab had beneficial effects on FEV 1 and FVC with distinct post-initiation trajectories., (© 2024 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

During veno-venous extracorporeal membrane oxygenation (V-V ECMO), blood is drained from the central venous circulation to be oxygenated and decarbonated by an artificial lung. It is then reinfused into the right heart and pulmonary circulation where further gas-exchange occurs. Each of these steps is characterized by a peculiar physiology that this manuscript analyses, with the aim of providing bedside tools for clinical care: we begin by describing the factors that affect the efficiency of blood drainage, such as patient and cannulae position, fluid status, cardiac output and ventilatory strategies. We then dig into the complexity of extracorporeal gas-exchange, with particular reference to the effects of extracorporeal blood-flow (ECBF), fraction of delivered oxygen (FdO2) and sweep gas-flow (SGF) on oxygenation and decarbonation. Subsequently, we focus on the reinfusion of arterialized blood into the right heart, highlighting the effects on recirculation and, more importantly, on right ventricular function. The importance and challenges of haemodynamic monitoring during V-V ECMO are also analysed. Finally, we detail the interdependence between extracorporeal circulation, native lung function and mechanical ventilation in providing adequate arterial blood gases while allowing lung rest. In the absence of evidence-based strategies to care for this particular group of patients, clinical practice is underpinned by a sound knowledge of the intricate physiology of V-V ECMO., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the authorship, and/or publication of this article.

Rationale: It is unclear whether extracorporeal CO 2 removal (ECCO 2 R) can reduce the rate of intubation or the total time on invasive mechanical ventilation (IMV) in adults experiencing an exacerbation of chronic obstructive pulmonary disease (COPD). Objectives: To determine whether ECCO 2 R increases the number of ventilator-free days within the first 5 days postrandomization (VFD-5) in exacerbation of COPD in patients who are either failing noninvasive ventilation (NIV) or who are failing to wean from IMV. Methods: This randomized clinical trial was conducted in 41 U.S. institutions (2018-2022) (ClinicalTrials.gov ID: NCT03255057). Subjects were randomized to receive either standard care with venovenous ECCO 2 R (NIV stratum: n  = 26; IMV stratum: n  = 32) or standard care alone (NIV stratum: n  = 22; IMV stratum: n  = 33). Measurements and Main Results: The trial was stopped early because of slow enrollment and enrolled 113 subjects of the planned sample size of 180. There was no significant difference in the median VFD-5 between the arms controlled by strata ( P  = 0.36). In the NIV stratum, the median VFD-5 for both arms was 5 days (median shift = 0.0; 95% confidence interval [CI]: 0.0-0.0). In the IMV stratum, the median VFD-5 in the standard care and ECCO 2 R arms were 0.25 and 2 days, respectively; median shift = 0.00 (95% confidence interval: 0.00-1.25). In the NIV stratum, all-cause in-hospital mortality was significantly higher in the ECCO 2 R arm (22% vs. 0%, P  = 0.02) with no difference in the IMV stratum (17% vs. 15%, P  = 0.73). Conclusions: In subjects with exacerbation of COPD, the use of ECCO 2 R compared with standard care did not improve VFD-5. Clinical trial registered with www.clinicaltrials.gov (NCT03255057).

Introduction: Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the sinonasal mucosa with distinct endotypes including type 2 (T2) high eosinophilic CRS with nasal polyps (eCRSwNP), T2 low non-eosinophilic CRS with nasal polyps (neCRSwNP), and CRS without nasal polyps (CRSsNP)., Methods: Given the heterogeneity of disease, we hypothesized that assessment of single cell RNA sequencing (scRNA-seq) across this spectrum of disease would reveal connections between infiltrating and activated immune cells and the epithelial and stromal populations that reside in sinonasal tissue., Results: Here we find increased expression of genes encoding glycolytic enzymes in epithelial cells (EpCs), stromal cells, and memory T-cell subsets from patients with eCRSwNP, as compared to healthy controls. In basal EpCs, this is associated with a program of cell motility and Rho GTPase effector expression. Across both stromal and immune subsets, glycolytic programming was associated with extracellular matrix interactions, proteoglycan generation, and collagen formation. Furthermore, we report increased cell-cell interactions between EpCs and stromal/immune cells in eCRSwNP compared to healthy control tissue, and we nominate candidate receptor-ligand pairs that may drive tissue remodeling., Discussion: These findings support a role for glycolytic reprograming in T2-elicited tissue remodeling and implicate increased cellular crosstalk in eCRSwNP., Competing Interests: NB has served on scientific advisory boards for Regeneron. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be constructed as a potential conflict of interest., (Copyright © 2024 Huang, Mandanas, Djeddi, Fernandez-Salinas, Gutierrez-Arcelus and Barrett.)

The olfactory neuroepithelium serves as a sensory organ for odors and forms part of the nasal mucosal barrier. Olfactory sensory neurons are surrounded and supported by epithelial cells. Among them, microvillous cells (MVCs) are strategically positioned at the apical surface, but their specific functions are enigmatic, and their relationship to the other specialized epithelial cells is unclear. Here, we establish that the family of MVCs comprises tuft cells and ionocytes in both mice and humans. Integrating analysis of the respiratory and olfactory epithelia, we define the distinct receptor expression of TRPM5 + tuft-MVCs compared with Gɑ-gustducin high respiratory tuft cells and characterize a previously undescribed population of glandular DCLK1 + tuft cells. To establish how allergen sensing by tuft-MVCs might direct olfactory mucosal responses, we used an integrated single-cell transcriptional and protein analysis. Inhalation of Alternaria induced mucosal epithelial effector molecules including Chil4 and a distinct pathway leading to proliferation of the quiescent olfactory horizontal basal stem cell (HBC) pool, both triggered in the absence of olfactory apoptosis. Alternaria- and ATP-elicited HBC proliferation was dependent on TRPM5 + tuft-MVCs, identifying these specialized epithelial cells as regulators of olfactory stem cell responses. Together, our data provide high-resolution characterization of nasal tuft cell heterogeneity and identify a function of TRPM5 + tuft-MVCs in directing the olfactory mucosal response to allergens.

The Extracorporeal Life Support Organization (ELSO) maintains the world's largest extracorporeal membrane oxygenation (ECMO) registry by volume, center participation, and international scope. This 2022 ELSO Registry Report describes the program characteristics of ECMO centers, processes of ECMO care, and reported outcomes. Neonates (0-28 days), children (29 days-17 years), and adults (≥18 years) supported with ECMO from 2009 through 2022 and reported to the ELSO Registry were included. This report describes adjunctive therapies, support modes, treatments, complications, and survival outcomes. Data are presented descriptively as counts and percent or median and interquartile range (IQR) by year, group, or level. Missing values were excluded before calculating descriptive statistics. Complications are reported per 1,000 ECMO hours. From 2009 to 2022, 154,568 ECMO runs were entered into the ELSO Registry. Seven hundred and eighty centers submitted data during this time (557 in 2022). Since 2009, the median annual number of adult ECMO runs per center per year increased from 4 to 15, whereas for pediatric and neonatal runs, the rate decreased from 12 to 7. Over 50% of patients were transferred to the reporting ECMO center; 20% of these patients were transported with ECMO. The use of prone positioning before respiratory ECMO increased from 15% (2019) to 44% (2021) for adults during the coronavirus disease-2019 (COVID-19) pandemic. Survival to hospital discharge was greatest at 68.5% for neonatal respiratory support and lowest at 29.5% for ECPR delivered to adults. By 2022, the Registry had enrolled its 200,000th ECMO patient and 100,000th patient discharged alive. Since its inception, the ELSO Registry has helped centers measure and compare outcomes across its member centers and strategies of care. Continued growth and development of the Registry will aim to bolster its utility to patients and centers., Competing Interests: Disclosure: J.E.T. is the Chair of the Registry Committee of the Extracorporeal Life Support Organization (ELSO). P.S.B. receives salary support from ELSO. G.M. is the President of ELSO. M.P. is the Immediate past President of ELSO. D.B. receives research support from and consults for LivaNova. He has been on the medical advisory boards for Abiomed, Xenios, Medtronic, Inspira, and Cellenkos. He is the President-elect of ELSO and the Chair of the Executive Committee of the International ECMO Network (ECMONet), and he writes for UpToDate. M.A., A.H., and K.R. are the Immediate Past Co-Chairs of the Scientific Oversight Committee of ELSO. P.R. is the Executive Director of ELSO. C.S. is the Chief Executive Officer (CEO) of ELSO. N.A.B. is the President of European Chapter of ELSO. N.A.B. has been on the medical advisory boards for Xenios and Baxter. T.M. is on the Board of Directors of ELSO. R.D.G. is the President of the Latin-American Chapter of ELSO. P.M.K. is the President of the South West Asia and Africa Chapter of ELSO. J.F.F. is the President of Asia-Pacific Chapter of ELSO. P.M.A.A. is Treasurer of ELSO Board of Directors. P.M.A.A. is funded by U.S. DoD PRMRP Clinical Trial Award #W81XWH2210301, NIH (R13HD104432) and FDA UCSF-Stanford Center of Excellence in Regulatory Sciences and Innovation (U01FD004979/U01FD005978). None of the funding sources were involved in the design or conduct of the study, collection, management, analysis, or interpretation of the data, or preparation, review, or approval of the manuscript. No other conflicts of interest reported. R.P.B. is a member of the Board of Directors for ELSO and receives funding from the National Heart, Lung, And Blood Institute (R01 HL153519)., (Copyright © ASAIO 2024.)

Rationale: Respiratory metagenomics (RMg) needs evaluation in a pilot service setting to determine utility and inform implementation into routine clinical practice. Objectives: Feasibility, performance, and clinical impacts on antimicrobial prescribing and infection control were recorded during a pilot RMg service. Methods: RMg was performed on 128 samples from 87 patients with suspected lower respiratory tract infection (LRTI) on two general and one specialist respiratory ICUs at Guy's and St Thomas' NHS Foundation Trust, London. Measurements and Main Results: During the first 15 weeks, RMg provided same-day results for 110 samples (86%), with a median turnaround time of 6.7 hours (interquartile range = 6.1-7.5 h). RMg was 93% sensitive and 81% specific for clinically relevant pathogens compared with routine testing. Forty-eight percent of RMg results informed antimicrobial prescribing changes (22% escalation; 26% deescalation) with escalation based on speciation in 20 out of 24 cases and detection of acquired-resistance genes in 4 out of 24 cases. Fastidious or unexpected organisms were reported in 21 samples, including anaerobes ( n  = 12), Mycobacterium tuberculosis , Tropheryma whipplei , cytomegalovirus, and Legionella pneumophila ST1326, which was subsequently isolated from the bedside water outlet. Application to consecutive severe community-acquired LRTI cases identified Staphylococcus aureus (two with SCCmec and three with luk F/S virulence determinants), Streptococcus pyogenes ( emm1- M1uk clone), S. dysgalactiae subspecies equisimilis (STG62647A), and Aspergillus fumigatus with multiple treatments and public health impacts. Conclusions: This pilot study illustrates the potential of RMg testing to provide benefits for antimicrobial treatment, infection control, and public health when provided in a real-world critical care setting. Multicenter studies are now required to inform future translation into routine service.

Objectives: Lower tidal volume ventilation (targeting 3 mL/kg predicted body weight, PBW) facilitated by extracorporeal carbon dioxide removal (ECCO 2 R) has been investigated as a potential therapy for acute hypoxemic respiratory failure (AHRF) in the pRotective vEntilation with veno-venouS lung assisT in respiratory failure (REST) trial. We investigated the effect of this strategy on cardiac function, and in particular the right ventricle., Design: Substudy of the REST trial., Setting: Nine U.K. ICUs., Patients: Patients with AHRF (Pao 2 /Fio 2 < 150 mm Hg [20 kPa])., Intervention: Transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements were collected at baseline and postrandomization in patients randomized to ECCO 2 R or usual care., Measurements: The primary outcome measures were a difference in tricuspid annular plane systolic excursion (TAPSE) on postrandomization echocardiogram and difference in NT-proBNP postrandomization., Results: There were 21 patients included in the echocardiography cohort (ECCO 2 R, n = 13; usual care, n = 8). Patient characteristics were similar in both groups at baseline. Median (interquartile range) tidal volumes were lower in the ECCO 2 R group compared with the usual care group postrandomization; 3.6 (3.1-4.2) mL/kg PBW versus 5.2 (4.9-5.7) mL/kg PBW, respectively ( p = 0.01). There was no difference in the primary outcome measure of mean (sd) TAPSE in the ECCO 2 R and usual care groups postrandomization; 21.3 (5.4) mm versus 20.1 (3.2) mm, respectively ( p = 0.60). There were 75 patients included in the NT-proBNP cohort (ECCO 2 R, n = 36; usual care, n = 39). Patient characteristics were similar in both groups at baseline. Median (interquartile range [IQR]) tidal volumes were lower in the ECCO 2 R group than the usual care group postrandomization; 3.8 (3.3-4.2) mL/kg PBW versus 6.7 (5.8-8.1) mL/kg PBW, respectively ( p < 0.0001). There was no difference in median (IQR) NT-proBNP postrandomization; 1121 (241-5370) pg/mL versus 1393 (723-4332) pg/mL in the ECCO 2 R and usual care groups, respectively ( p = 0.30)., Conclusions: In patients with AHRF, a reduction in tidal volume facilitated by ECCO 2 R, did not modify cardiac function., Competing Interests: Dr. McGuigan is funded by Belfast Health and Social Care Trust, Research Charitable Funds (reference J-2223-152). The funding body had no role in the design of the study, collection, analysis, and interpretation of data or in writing the article. Dr. Boyle reported receiving grants from the Northern Ireland Health and Social Care Research and Development Agency to undertake a sampling substudy within a clinical trial of extracorporeal carbon dioxide removal. Dr. McNamee reported receiving grants from the National Institute for Health Research Health Technology Assessment Programme during the conduct of the study and speaking fees from Baxter outside the submitted work. Dr. Szakmany is associate editor for social media, Critical Care Explorations and the Journal of the Intensive Care Society. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Monitoring the patient receiving veno-venous extracorporeal membrane oxygenation (VV ECMO) is challenging due to the complex physiological interplay between native and membrane lung. Understanding these interactions is essential to understand the utility and limitations of different approaches to respiratory monitoring during ECMO. We present a summary of the underlying physiology of native and membrane lung gas exchange and describe different tools for titrating and monitoring gas exchange during ECMO. However, the most important role of VV ECMO in severe respiratory failure is as a means of avoiding further ergotrauma. Although optimal respiratory management during ECMO has not been defined, over the last decade there have been advances in multimodal respiratory assessment which have the potential to guide care. We describe a combination of imaging, ventilator-derived or invasive lung mechanic assessments as a means to individualise management during ECMO., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background and Purpose: Extracorporeal membrane oxygenation (ECMO) continues to play an essential role in organ support in cardiogenic shock or acute respiratory distress syndrome and bridging to transplantation. The main purpose of the present survey was to define which clinical and organizational practices are adopted for the administration of physiotherapy in adult patients undergoing ECMO support worldwide., Methods: This international survey was conceived in November 2021. The survey launch was announced at the 10th EuroELSO (European ELSO chapter) Congress, London, May 2022., Results: The survey returned 32 questionnaires from 29 centers across 14 countries. 17 centers (53.1%) had more than 30 intensive care unit beds available and most (46.8%) were able to care for five to 10 patients on extracorporeal life support simultaneously. The predominant physiotherapist-to-patient ratio was 1:>5 (37.5%); physiotherapy was available 5/7 days and 7/7 days by 31.2% and 25% respectively. Respiratory physiotherapy was not defined by a specific protocol in most centers (46.8%) while 31.2% declared that the treatment commences less than 12 h after sedation is stopped/reduced. Mostly, early physiotherapy in non-cooperative ventilated patients was provided within the first 48 h (68.6%) and consisted of as passive range of motion, in-bed positioning, and splinting. Postural passages and sitting were provided to patients and walking was included in those advanced motor activities which are part of the treatment., Conclusion: Physiotherapy in patients on ECLS is feasible, however substantial variability exists between centers with a trend of delivering not protocolized and understaffed rehabilitation practices., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) with femoral access is obtained through unilateral or bilateral groin cannulation. Whether one cannulation strategy is associated with a lower risk for limb ischemia remains unknown. We aim to assess if one strategy is preferable., Design: A retrospective cohort study based on the Extracorporeal Life Support Organization registry., Setting: ECMO centers worldwide included in the Extracorporeal Life Support Organization registry., Patients: All adult patients (≥ 18 yr) who received peripheral venoarterial ECMO with femoral access and were included from 2014 to 2020., Interventions: Unilateral or bilateral femoral cannulation., Measurements and Main Results: The primary outcome was the occurrence of limb ischemia defined as a composite endpoint including the need for a distal perfusion cannula (DPC) after 6 hours from implantation, compartment syndrome/fasciotomy, amputation, revascularization, and thrombectomy. Secondary endpoints included bleeding at the peripheral cannulation site, need for vessel repair, vessel repair after decannulation, and in-hospital death. Propensity score matching was performed to account for confounders. Overall, 19,093 patients underwent peripheral venoarterial ECMO through unilateral ( n = 11,965) or bilateral ( n = 7,128) femoral cannulation. Limb ischemia requiring any intervention was not different between both groups (bilateral vs unilateral: odds ratio [OR], 0.92; 95% CI, 0.82-1.02). However, there was a lower rate of compartment syndrome/fasciotomy in the bilateral group (bilateral vs unilateral: OR, 0.80; 95% CI, 0.66-0.97). Bilateral cannulation was also associated with lower odds of cannulation site bleeding (bilateral vs unilateral: OR, 0.87; 95% CI, 0.76-0.99), vessel repair (bilateral vs unilateral: OR, 0.55; 95% CI, 0.38-0.79), and in-hospital mortality (bilateral vs unilateral: OR, 0.85; 95% CI, 0.81-0.91) compared with unilateral cannulation. These findings were unchanged after propensity matching., Conclusions: This study showed no risk reduction for overall limb ischemia-related events requiring DPC after 6 hours when comparing bilateral to unilateral femoral cannulation in peripheral venoarterial ECMO. However, bilateral cannulation was associated with a reduced risk for compartment syndrome/fasciotomy, lower rates of bleeding and vessel repair during ECMO, and lower in-hospital mortality., Competing Interests: Drs. Brodie’s and Lorusso’s institutions received funding from LivaNova. Drs. Brodie, Broman, and Wiedemann received funding from Xenios AG (Heilbronn, Germany). Dr. Brodie received funding from Abided, Medtronic, Abiomed, Inspira, Xenios, and Cellenkos; he received research support from ALung Technologies; and he disclosed that he is President-elect of the Extracorporeal Life Support Organization (ELSO) and Chair of the Executive Committee of the International Extracorporeal Membrane Oxygenation Network. Dr. Taccone is a scientific advisor for Eurosets and Xenios. Drs. Belliato and Broman received funding from Eurosets srl (Medolla, Italy). Dr. Belliato received funding from Eswtor Spa and Hamilton Medical. Dr. Wiedemann received funding from Abbott; he is a scientific advisor for Xenios/Fresenius. Dr. Tonna’s institution received funding from the National Heart, Lung, and Blood Institute; he disclosed that he is Chair-Elect of the ELSO Registry Committee. Drs. Tonna and Barbaro received support for article research from the U.S. National Institutes of Health. Dr. Barbaro’s institution received funding from the NHBLI (R01 HL153519, R01 HD015434, and K12 HL138039); he disclosed that he is the ELSO Registry Chair. Dr. MacLaren disclosed that he serves on the Board of Directors of ELSO. Dr. Lorusso’s institution received funding from Medtronic, LivaNova, Abiomed, Getinge, and Eurosets; he disclosed that he is a member of the Medical Advisory Board for Eurosets, HemoCue, and Xenios. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2023 by the Society of Critical Care Medicine and Wolters Kluwer Health, Inc. All Rights Reserved.)

Background: Despite its diagnostic and prognostic importance, physiologic dead space fraction is not included in the current ARDS definition or severity classification. ARDS caused by COVID-19 (C-ARDS) is characterized by increased physiologic dead space fraction and hypoxemia. Our aim was to investigate the relationship between dead space indices, markers of inflammation, immunothrombosis, severity and intensive care unit (ICU) mortality., Results: Retrospective data including demographics, gas exchange, ventilatory parameters, and respiratory mechanics in the first 24 h of invasive ventilation. Plasma concentrations of D-dimers and ferritin were not significantly different across C-ARDS severity categories. Weak relationships were found between D-dimers and VR (r = 0.07, p = 0.13), P ET CO 2 /PaCO 2 (r = -0.1, p = 0.02), or estimated dead space fraction (r = 0.019, p = 0.68). Age, PaO 2 /FiO 2 , pH, P ET CO 2 /PaCO 2 and ferritin, were independently associated with ICU mortality. We found no association between D-dimers or ferritin and any dead-space indices adjusting for PaO 2 /FiO 2 , days of ventilation, tidal volume, and respiratory system compliance., Conclusions: We report no association between dead space and inflammatory markers in mechanically ventilated patients with C-ARDS. Our results support theories suggesting that multiple mechanisms, in addition to immunothrombosis, play a role in the pathophysiology of respiratory failure and degree of dead space in C-ARDS., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest in writing this manuscript., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Data on the prevalence and clinical impact of extrapulmonary findings at screening computed tomography (CT) on initiation of veno-venous extracorporeal membrane oxygenation (V-V ECMO) are limited. We aimed to identify the prevalence of extrapulmonary findings on screening CT following V-V ECMO initiation. We hypothesized that extrapulmonary findings would influence clinical management and outcome., Methods: Retrospective analysis (2011-2021) of admission screening CT including head, abdomen and pelvis with contrast of consecutive patients on initiation of V-V ECMO. CT findings identified by the attending consultant radiologist were extracted. Demographics, admission physiological and laboratory data, clinical decision-making following CT and ECMO ICU mortality were recorded from the electronic medical record. We used multivariable logistic regression and Kaplan-Meier curves to evaluate associations between extrapulmonary findings and ECMO ICU mortality., Results: Of the 833 patients receiving V-V ECMO, 761 underwent routine admission CT (91.4%). ECMO ICU length of stay was 19 days (IQR 12-23); ICU mortality at the ECMO centre was 18.9%. An incidental extrapulmonary finding was reported in 227 patients (29.8%), leading to an invasive procedure in 12/227 cases (5.3%) and a change in medical management (mainly in anticoagulation strategy) in 119/227 (52.4%). Extrapulmonary findings associated with mortality were intracranial haemorrhage (OR 2.34 (95% CI 1.31-4.12), cerebral infarction (OR 3.59 (95% CI 1.26-9.86) and colitis (OR 2.80 (95% CI 1.35-5.67)., Conclusions: Screening CT frequently identifies extrapulmonary findings of clinical significance. Newly detected intracranial haemorrhage, cerebral infarction and colitis were associated with increased ICU mortality., (© 2023. La Société de Réanimation de Langue Francaise = The French Society of Intensive Care (SRLF).)

In this retrospective observational cohort study, we aimed to describe the rate of extracorporeal membrane oxygenation (ECMO) circuit change, the associated risk factors and its relationship with patient characteristics and outcome in patients receiving venovenous (VV) ECMO at our center between January 2015 and November 2017. Twenty-seven percent of the patients receiving VV ECMO (n = 224) had at least one circuit change, which was associated with lower ICU survival (68% vs 82% p=0.032) and longer ICU stay (30 vs . 17 days p < 0.001). Circuit duration was similar when stratified by gender, clinical severity, or prior circuit change. Hematological abnormalities and increased transmembrane lung pressure (TMLP) were the most frequent indication for circuit change. The change in transmembrane lung resistance (Δ TMLR) gave better prediction of circuit change than TMLP, TMLR, or ΔTMLP. Low postoxygenator PO 2 was indicated as a reason for one-third of the circuit changes. However, the ECMO oxygen transfer was significantly higher in cases of circuit change with documented "low postoxygenator PO 2 " than those without (244 ± 62 vs. 200 ± 57 ml/min; p = 0.009). The results suggest that circuit change in VV ECMO is associated with worse outcomes, that the Δ TMLR is a better predictor of circuit change than TMLP, and that the postoxygenator PO 2 is an unreliable proxy for the oxygenator function., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © ASAIO 2023.)

Background: Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a type 2 (T2) inflammatory disease associated with an increased number of airway basal cells (BCs). Recent studies have identified transcriptionally distinct BCs, but the molecular pathways that support or inhibit human BC proliferation and differentiation are largely unknown., Objective: We sought to determine the role of T2 cytokines in regulating airway BCs., Methods: Single-cell and bulk RNA sequencing of sinus and lung airway epithelial cells was analyzed. Human sinus BCs were stimulated with IL-4 and IL-13 in the presence and absence of inhibitors of IL-4R signaling. Confocal analysis of human sinus tissue and murine airway was performed. Murine BC subsets were sorted for RNA sequencing and functional assays. Fate labeling was performed in a murine model of tracheal injury and regeneration., Results: Two subsets of BCs were found in human and murine respiratory mucosa distinguished by the expression of basal cell adhesion molecule (BCAM). BCAM expression identifies airway stem cells among P63 + KRT5 + NGFR + BCs. In the sinonasal mucosa, BCAM hi BCs expressing TSLP, IL33, CCL26, and the canonical BC transcription factor TP63 are increased in patients with CRSwNP. In cultured BCs, IL-4/IL-13 increases the expression of BCAM and TP63 through an insulin receptor substrate-dependent signaling pathway that is increased in CRSwNP., Conclusions: These findings establish BCAM as a marker of airway stem cells among the BC pool and demonstrate that airway epithelial remodeling in T2 inflammation extends beyond goblet cell metaplasia to the support of a BC stem state poised to perpetuate inflammation., (Copyright © 2023. Published by Elsevier Inc.)

Introduction : Simulation training offers an authentic team-based learning opportunity without risk to real patients. The Educational Corner at the annual congress of the European Branch of Extracorporeal Life Support Organisation (EuroELSO) provided an opportunity for multiple simulation training sessions facilitated by experts from all over the world. Aim : We aimed to review the educational impact of EuroELSO Educational Corner and whether it provides a quality ECLS training to a wide spectrum of multidisciplinary international attendees utilising high and low fidelity simulation, workshops and hands on sessions. Methods : During the congress, 43 sessions were conducted dedicated to ECLS education with identified educational objectives. The sessions focused on management of adults and children on V-V or V-A ECMO. Adult sessions covered emergencies on mechanical circulatory support with management of LVAD and Impella, managing refractory hypoxemia on V-V ECMO, emergencies on ECMO, renal replacement therapy on ECMO, V-V ECMO, ECPR cannulation and performing perfect simulation. Paediatric sessions covered ECPR neck and central cannulation, renal replacement on ECMO, troubleshooting, cannulation workshop, V-V recirculation, ECMO for single ventricle, PIMS-TS and CDH, ECMO transport and neurological injury. Results : The Educational Corner was attended by more than 400 participants over the two congress days. Majority of responders (88%) reported that training sessions met the set educational goals and objectives and that this would change their current practice. Almost all (94%) reported that they received useful information and 95% would recommend the session to their colleagues. Conclusion : The Educational Corner, as an integral component of the annual EuroELSO congress, achieved the set educational goals and provided quality education based on the recipient survey. Structured multidisciplinary ECLS education with standardised curriculum and feedback is an important key step in delivering quality training to an international audience. Standardisation of European ECLS education remains an important focus of the EuroELSO.

Background: Adverse neurological events during extracorporeal membrane oxygenation (ECMO) are common and may be associated with devastating consequences. Close monitoring, early identification and prompt intervention can mitigate early and late neurological morbidity. Neuromonitoring and neurocognitive/neurodevelopmental follow-up are critically important to optimize outcomes in both adults and children., Objective: To assess current practice of neuromonitoring during ECMO and neurocognitive/neurodevelopmental follow-up after ECMO across Europe and to inform the development of neuromonitoring and follow-up guidelines., Methods: The EuroELSO Neurological Monitoring and Outcome Working Group conducted an electronic, web-based, multi-institutional, multinational survey in Europe., Results: Of the 211 European ECMO centres (including non-ELSO centres) identified and approached in 23 countries, 133 (63%) responded. Of these, 43% reported routine neuromonitoring during ECMO for all patients, 35% indicated selective use, and 22% practiced bedside clinical examination alone. The reported neuromonitoring modalities were NIRS ( n = 88, 66.2%), electroencephalography ( n = 52, 39.1%), transcranial Doppler ( n = 38, 28.5%) and brain injury biomarkers ( n = 33, 24.8%). Paediatric centres (67%) reported using cranial ultrasound, though the frequency of monitoring varied widely. Before hospital discharge following ECMO, 50 (37.6%) reported routine neurological assessment and 22 (16.5%) routinely performed neuroimaging with more paediatric centres offering neurological assessment (65%) as compared to adult centres (20%). Only 15 (11.2%) had a structured longitudinal follow-up pathway (defined followup at regular intervals), while 99 (74.4%) had no follow-up programme. The majority ( n = 96, 72.2%) agreed that there should be a longitudinal structured follow-up for ECMO survivors., Conclusions: This survey demonstrated significant variability in the use of different neuromonitoring modalities during and after ECMO. The perceived importance of neuromonitoring and follow-up was noted to be very high with agreement for a longitudinal structured follow-up programme, particularly in paediatric patients. Scientific society endorsed guidelines and minimum standards should be developed to inform local protocols.

Background: Corticosteroids are used to treat COVID-19 pneumonia. However, the optimal dose is unclear. This study describes the association between corticosteroid exposure with disease severity and outcome in COVID-19 pneumonia., Methods: This is a single-centre retrospective, observational study including adult ICU patients who received systemic corticosteroids for COVID-19 pneumonia between March 2020 and March 2021. We recorded patient characteristics, disease severity, total steroid exposure, respiratory support and gas exchange data, and 90-day mortality., Results: We included 362 patients. We allocated patients to groups with increasing disease severity according to the highest level of respiratory support that they received: high-flow nasal oxygen or continuous positive airway pressure (HFNO/CPAP) in 12.7%, invasive mechanical ventilation (IMV) in 61.6%, and extracorporeal membrane oxygenation (ECMO) in 25.7%. For these three groups, the median (inter-quartile range [IQR]) age was 61 (54-71) vs 58 (50-66) vs 46 (38-53) yr, respectively ( P <0.001); median (IQR) APACHE (Acute Physiology and Chronic Health Evaluation) II scores were 12 (9-15) vs 14 (12-18) vs 15 (12-17), respectively ( P =0.006); the median (IQR) lowest P a O 2 /FiO 2 ratio was 15.1 (11.8-21.7) vs 15.1 (10.7-22.2) vs 9.5 (7.9-10.9) kPa, respectively ( P <0.001). Ninety-day mortality was 9% vs 27% vs 37% ( P =0.002). Median (IQR) dexamethasone-equivalent exposure was 37 (24-62) vs 174 (86-504) vs 535 (257-1213) mg ( P <0.001). 'Pulsed' steroids were administered to 26% of the IMV group and 48% of the ECMO group. Patients with higher disease severity who received pulse steroids had a higher 90-day mortality., Conclusions: Corticosteroid exposure increased with the severity of COVID-19 pneumonia. Pulsed dose steroids were used more frequently in patients receiving greater respiratory support. Future studies should address patient selection and outcomes associated with pulsed dose steroids in patients with severe and deteriorating COVID-19 pneumonia., Competing Interests: The authors declare they have no conflicts of interest., (© 2023 The Author(s).)

Background: Acute kidney injury (AKI) is common in critically ill patients with coronavirus disease-19 (COVID-19). We aimed to explore the changes in AKI epidemiology between the first and the second COVID wave in the United Kingdom (UK)., Methods: This was an observational study of critically ill adult patients with COVID-19 in an expanded tertiary care intensive care unit (ICU) in London, UK. Baseline characteristics, organ support, COVID-19 treatments, and patient and kidney outcomes up to 90 days after discharge from hospital were compared., Results: A total of 772 patients were included in the final analysis (68% male, mean age 56 ± 13.6). Compared with wave 1, patients in wave 2 were older, had higher body mass index and clinical frailty score, but lower baseline serum creatinine and C-reactive protein (CRP). The proportion of patients receiving invasive mechanical ventilation (MV) on ICU admission was lower in wave 2 (61% vs 80%; p < 0.001). AKI incidence within 14 days of ICU admission was 76% in wave 1 and 51% in wave 2 (p < 0.001); in wave 1, 32% received KRT compared with 13% in wave 2 (p < 0.001). Patients in wave 2 had significantly lower daily cumulative fluid balance (FB) than in wave 1. Fewer patients were dialysis dependent at 90 days in wave 2 (1% vs. 4%; p < 0.001)., Conclusions: In critically ill adult patients admitted to ICU with COVID-19, the risk of AKI and receipt of KRT significantly declined in the second wave. The trend was associated with less MV, lower PEEP and lower cumulative FB., Trial Registration: NCT04445259., (© 2022. The Author(s).)

Competing Interests: Competing interests: I have read and understood BMJ policy on declaration of interests and declare the following interests: none.

Background: Acute kidney injury (AKI) is a frequent complication in patients with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO). However, little is known of long-term kidney function in ECMO survivors. We aimed to assess the long-term mortality and kidney outcomes in adult patients treated with veno-venous ECMO (VV-ECMO)., Methods: This was a single-centre retrospective study of adult patients (≥ 18 years old) who were treated with VV-ECMO at a commissioned ECMO centre in the UK between 1st September 2010, and 30th November 2016. AKI was defined and staged using the serum creatinine and urine output criteria of the Kidney Diseases: Improving Global Outcomes (KDIGO) classification. The primary outcome was 1-year mortality. Secondary outcomes were long-term mortality (up to March 2020), 1-year incidence of end-stage kidney disease (ESKD) or chronic kidney disease (CKD) among AKI patients who received renal replacement therapy (AKI-RRT), AKI patients who did not receive RRT (AKI-no RRT) and patients without AKI (non-AKI)., Results: A total of 300 patients [57% male; median age 44.5; interquartile range (IQR) 34-54] were included in the final analysis. Past medical histories included diabetes (12%), hypertension (17%), and CKD (2.3%). The main cause of severe respiratory failure was pulmonary infection (72%). AKI occurred in 230 patients (76.7%) and 59.3% received renal replacement therapy (RRT). One-year mortality was 32% in AKI-RRT patients vs. 21.4% in non-AKI patients (p = 0.014). The median follow-up time was 4.35 years. Patients who received RRT had a higher risk of 1-year mortality than those who did not receive RRT (adjusted HR 1.80, 95% CI 1.06, 3.06; p = 0.029). ESKD occurred in 3 patients, all of whom were in the AKI-RRT group. At 1-year, 41.2% of survivors had serum creatinine results available. Among these, CKD was prevalent in 33.3% of AKI-RRT patients vs. 4.3% in non-AKI patients (p = 0.004)., Conclusions: VV-EMCO patients with AKI-RRT had high long-term mortality. Monitoring of kidney function after hospital discharge was poor. In patients with follow-up creatinine results available, the CKD prevalence was high at 1 year, especially in AKI-RRT patients. More awareness about this serious long-term complication and appropriate follow-up interventions are required., (© 2022. The Author(s).)

Background: Mast cells (MCs) are pleiotropic cells that accumulate in the esophagus of patients with eosinophilic esophagitis (EoE) and are thought to contribute to disease pathogenesis, yet their properties and functions in this organ are largely unknown., Objectives: This study aimed to perform a comprehensive molecular and spatial characterization of esophageal MCs in EoE., Methods: Esophageal biopsies obtained from patients with active EoE, patients with EoE in histologic remission, and individuals with histologically normal esophageal biopsies and no history of esophageal disease (ie, control individuals) were subject to single-cell RNA sequencing, flow cytometry, and immunofluorescence analyses., Results: This study probed 39,562 single esophageal cells by single-cell RNA sequencing; approximately 5% of these cells were MCs. Dynamic MC expansion was identified across disease states. During homeostasis, TPSAB1 high AREG high resident MCs were mainly detected in the lamina propria and exhibited a quiescent phenotype. In patients with active EoE, resident MCs assumed an activated phenotype, and 2 additional proinflammatory MC populations emerged in the intraepithelial compartment, each linked to a proliferating MKI67 high cluster. One proinflammatory activated MC population, marked as KIT high IL1RL1 high FCER1A low , was not detected in disease remission (termed "transient MC"), whereas the other population, marked as CMA1 high CTSG high , was detected in disease remission where it maintained an activated state (termed "persistent MC"). MCs were prominent producers of esophageal IL-13 mRNA and protein, a key therapeutic target in EoE., Conclusions: Esophageal MCs comprise heterogeneous populations with transcriptional signatures associated with distinct spatial compartmentalization and EoE disease status. In active EoE, they assume a proinflammatory state and locally proliferate, and they remain activated and poised to reinitiate inflammation even during disease remission., (Copyright © 2022 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Patients presenting with acute hypercapnic respiratory failure due to exacerbations of chronic obstructive pulmonary disease (AECOPD) are typically managed with non-invasive ventilation (NIV). The impact of low-flow extracorporeal carbon dioxide removal (ECCO 2 R) on outcome in these patients has not been explored in randomised trials., Methods: Open-label randomised trial comparing NIV (NIV arm) with ECCO 2 R (ECCO 2 R arm) in patients with AECOPD at high risk of NIV failure (pH < 7.30 after ≥ 1 h of NIV). The primary endpoint was time to cessation of NIV. Secondary outcomes included device tolerance and complications, changes in arterial blood gases, hospital survival., Results: Eighteen patients (median age 67.5, IQR (61.5-71) years; median GOLD stage 3 were enrolled (nine in each arm). Time to NIV discontinuation was shorter with ECCO 2 R (7:00 (6:18-8:30) vs 24:30 (18:15-49:45) h, p = 0.004). Arterial pH was higher with ECCO 2 R at 4 h post-randomisation (7.35 (7.31-7.37) vs 7.25 (7.21-7.26), p < 0.001). Partial pressure of arterial CO 2 (PaCO 2 ) was significantly lower with ECCO 2 R at 4 h (6.8 (6.2-7.15) vs 8.3 (7.74-9.3) kPa; p = 0.024). Dyspnoea and comfort both rapidly improved with commencement of ECCO 2 R. There were no severe or life-threatening complications in the study population. There were no episodes of major bleeding or red blood cell transfusion in either group. ICU and hospital length of stay were longer with ECCO 2 R, and there was no difference in 90-day mortality or functional outcomes at follow-up., Interpretation: There is evidence of benefit associated with ECCO 2 R with time to improvement in respiratory acidosis, in respiratory physiology and an immediate improvement in patient comfort and dyspnoea with commencement of ECCO 2 R. In addition, there was minimal clinically significant adverse events associated with ECCO 2 R use in patients with AECOPD at risk of failing or not tolerating NIV. However, the ICU and hospital lengths of stay were longer in the ECCO 2 R for similar outcomes. Trial registration The trial is prospectively registered on ClinicalTrials.gov: NCT02086084. Registered on 13th March 2014, https://clinicaltrials.gov/ct2/show/NCT02086084?cond=ecco2r&draw=2&rank=8., (© 2022. The Author(s).)

Type 2 inflammation (T2I) accompanies many inflammatory diseases. In a recent issue of Cell, Ahrends et al. demonstrate that helminth-elicited T2I preserves excitatory neurons and enteric function through the expansion of Arginase-1 (Arg-1)-expressing macrophages, thereby extending our understanding of the protective functions that T2I can orchestrate in inflamed barrier tissue., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Activation of the innate immune system via pattern recognition receptors (PRRs) is key to generate lasting adaptive immunity. PRRs detect unique chemical patterns associated with invading microorganisms, but whether and how the physical properties of PRR ligands influence the development of the immune response remains unknown. Through the study of fungal mannans, we show that the physical form of PRR ligands dictates the immune response. Soluble mannans are immunosilent in the periphery but elicit a potent pro-inflammatory response in the draining lymph node (dLN). By modulating the physical form of mannans, we developed a formulation that targets both the periphery and the dLN. When combined with viral glycoprotein antigens, this mannan formulation broadens epitope recognition, elicits potent antigen-specific neutralizing antibodies, and confers protection against viral infections of the lung. Thus, the physical properties of microbial ligands determine the outcome of the immune response and can be harnessed for vaccine development., Competing Interests: Declaration of interests F.B., E.N., T.R.O., I.Z., D.J.D., and O.L. are named inventors on invention disclosures and patents involving vaccine adjuvants. S.J.E. is a founder of TSCAN Therapeutics, ImmuneID, MAZE Therapeutics, and Mirimus. S.J.E. serves on the scientific advisory board of Homology Medicines, TSCAN Therapeutics, MAZE Therapetics, and XChem, and is an advisor for MPM, none of which impact this work. S.J.E. is an inventor on a patent application issued to the Brigham and Women’s Hospital (US20160320406A) that covers the use of the VirScan library to identify pathogen antibodies in blood. The other authors declare no commercial or financial conflict of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Aeroallergen sensing by airway epithelial cells triggers pathogenic immune responses leading to type 2 inflammation, the hallmark of chronic airway diseases such as asthma. Tuft cells are rare epithelial cells and the dominant source of interleukin-25 (IL-25), an epithelial cytokine, and cysteinyl leukotrienes (CysLTs), lipid mediators of vascular permeability and chemotaxis. How these two mediators derived from the same cell might cooperatively promote type 2 inflammation in the airways has not been clarified. Here, we showed that inhalation of the parent leukotriene C 4 (LTC 4 ) in combination with a subthreshold dose of IL-25 led to activation of two innate immune cells: inflammatory type 2 innate lymphoid cell (ILC2) for proliferation and cytokine production, and dendritic cells (DCs). This cooperative effect led to a much greater recruitment of eosinophils and CD4 + T cell expansion indicative of synergy. Whereas lung eosinophilia was dominantly mediated through the classical CysLT receptor CysLT 1 R, type 2 cytokines and activation of innate immune cells required signaling through CysLT 1 R and partially CysLT 2 R. Tuft cell–specific deletion of Ltc4s , the terminal enzyme required for CysLT production, reduced lung inflammation and the systemic immune response after inhalation of the mold aeroallergen Alternaria ; this effect was further enhanced by concomitant blockade of IL-25. Our findings identified a potent synergy of CysLTs and IL-25 downstream of aeroallergen-trigged activation of airway tuft cells leading to a highly polarized type 2 immune response and further implicate airway tuft cells as powerful modulators of type 2 immunity in the lungs.

Background: Clinical metagenomics (CMg) has the potential to be translated from a research tool into routine service to improve antimicrobial treatment and infection control decisions. The SARS-CoV-2 pandemic provides added impetus to realise these benefits, given the increased risk of secondary infection and nosocomial transmission of multi-drug-resistant (MDR) pathogens linked with the expansion of critical care capacity., Methods: CMg using nanopore sequencing was evaluated in a proof-of-concept study on 43 respiratory samples from 34 intubated patients across seven intensive care units (ICUs) over a 9-week period during the first COVID-19 pandemic wave., Results: An 8-h CMg workflow was 92% sensitive (95% CI, 75-99%) and 82% specific (95% CI, 57-96%) for bacterial identification based on culture-positive and culture-negative samples, respectively. CMg sequencing reported the presence or absence of β-lactam-resistant genes carried by Enterobacterales that would modify the initial guideline-recommended antibiotics in every case. CMg was also 100% concordant with quantitative PCR for detecting Aspergillus fumigatus from 4 positive and 39 negative samples. Molecular typing using 24-h sequencing data identified an MDR-K. pneumoniae ST307 outbreak involving 4 patients and an MDR-C. striatum outbreak involving 14 patients across three ICUs., Conclusion: CMg testing provides accurate pathogen detection and antibiotic resistance prediction in a same-day laboratory workflow, with assembled genomes available the next day for genomic surveillance. The provision of this technology in a service setting could fundamentally change the multi-disciplinary team approach to managing ICU infections. The potential to improve the initial targeted treatment and rapidly detect unsuspected outbreaks of MDR-pathogens justifies further expedited clinical assessment of CMg., (© 2021. The Author(s).)

Importance: In patients who require mechanical ventilation for acute hypoxemic respiratory failure, further reduction in tidal volumes, compared with conventional low tidal volume ventilation, may improve outcomes., Objective: To determine whether lower tidal volume mechanical ventilation using extracorporeal carbon dioxide removal improves outcomes in patients with acute hypoxemic respiratory failure., Design, Setting, and Participants: This multicenter, randomized, allocation-concealed, open-label, pragmatic clinical trial enrolled 412 adult patients receiving mechanical ventilation for acute hypoxemic respiratory failure, of a planned sample size of 1120, between May 2016 and December 2019 from 51 intensive care units in the UK. Follow-up ended on March 11, 2020., Interventions: Participants were randomized to receive lower tidal volume ventilation facilitated by extracorporeal carbon dioxide removal for at least 48 hours (n = 202) or standard care with conventional low tidal volume ventilation (n = 210)., Main Outcomes and Measures: The primary outcome was all-cause mortality 90 days after randomization. Prespecified secondary outcomes included ventilator-free days at day 28 and adverse event rates., Results: Among 412 patients who were randomized (mean age, 59 years; 143 [35%] women), 405 (98%) completed the trial. The trial was stopped early because of futility and feasibility following recommendations from the data monitoring and ethics committee. The 90-day mortality rate was 41.5% in the lower tidal volume ventilation with extracorporeal carbon dioxide removal group vs 39.5% in the standard care group (risk ratio, 1.05 [95% CI, 0.83-1.33]; difference, 2.0% [95% CI, -7.6% to 11.5%]; P = .68). There were significantly fewer mean ventilator-free days in the extracorporeal carbon dioxide removal group compared with the standard care group (7.1 [95% CI, 5.9-8.3] vs 9.2 [95% CI, 7.9-10.4] days; mean difference, -2.1 [95% CI, -3.8 to -0.3]; P = .02). Serious adverse events were reported for 62 patients (31%) in the extracorporeal carbon dioxide removal group and 18 (9%) in the standard care group, including intracranial hemorrhage in 9 patients (4.5%) vs 0 (0%) and bleeding at other sites in 6 (3.0%) vs 1 (0.5%) in the extracorporeal carbon dioxide removal group vs the control group. Overall, 21 patients experienced 22 serious adverse events related to the study device., Conclusions and Relevance: Among patients with acute hypoxemic respiratory failure, the use of extracorporeal carbon dioxide removal to facilitate lower tidal volume mechanical ventilation, compared with conventional low tidal volume mechanical ventilation, did not significantly reduce 90-day mortality. However, due to early termination, the study may have been underpowered to detect a clinically important difference., Trial Registration: ClinicalTrials.gov Identifier: NCT02654327.

Solitary chemosensory epithelial cells are scattered in most mucosal surfaces. They are referred to as tuft cells in the intestinal mucosa, brush cells in the trachea, and solitary chemosensory and microvillous cells in the nasal mucosa. They are the primary source of IL-25 in the epithelium and are also engaged in acetylcholine generation. We recently demonstrated that nasal solitary chemosensory (brush) cells can generate robust levels of cysteinyl leukotrienes in response to stimulation with calcium ionophore, aeroallergens, and danger-associated molecules, such as ATP and UTP, and this mechanism depends on brush cell expression of the purinergic receptor P2Y2. This protocol describes an effective method of nasal brush cell isolation in the mouse. The method is based on physical separation of the mucosal layer of the nasal cavity and pre-incubation with dispase, followed by digestion with papain solution. The single cell suspension obtained this way contains a high yield of brush cells for fluorescence-activated cell sorting (FACS), RNA-sequencing, and ex vivo assays. Graphic abstract: Workflow of nasal digestion for brush cell isolation., Competing Interests: Competing interestsThe authors declare no competing interests., (Copyright © 2021 The Authors; exclusive licensee Bio-protocol LLC.)

Leading organisations recommend follow-up of acute kidney injury (AKI) survivors, as these patients are at risk of long-term complications and increased mortality. Information transfer between specialties and from tertiary to primary care is essential to ensure timely and appropriate follow-up. Our aim was to examine the association between completeness of discharge documentation and subsequent follow-up of AKI survivors who received kidney replacement therapy (KRT) in the Intensive Care Unit (ICU). We retrospectively analysed the data of 433 patients who had KRT for AKI during ICU admission in a tertiary care centre in the UK between June 2017 and May 2018 and identified patients who were discharged from hospital alive. Patients with pre-existing end-stage kidney disease and patients who were transferred from hospitals outside the catchment area were excluded. The primary objective was to assess the completeness of discharge documentation from critical care and hospital; secondary objectives were to determine cardiovascular medications reconciliation after AKI, and to investigate kidney care and outcomes at 1 year. The development of AKI and the need for KRT were mentioned in 85 and 82% of critical care discharge letters, respectively. Monitoring of kidney function post-discharge was recommended in 51.6% of critical care and 36.3% of hospital discharge summaries. Among 35 patients who were prescribed renin-angiotensin-aldosterone system inhibitors before hospitalisation, 15 (42.9%) were not re-started before discharge from hospital. At 3 months, creatinine and urine protein were measured in 88.2 and 11.8% of survivors, respectively. The prevalence of chronic kidney disease stage III or worse increased from 27.2% pre-hospitalisation to 54.9% at 1 year ( p < 0.001). Our data demonstrate that discharge summaries of patients with AKI who received KRT lacked essential information. Furthermore, even in patients with appropriate documentation, renal follow-up was poor suggesting the need for more education and streamlined care pathways., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Choon, Lumlertgul, Cameron, Jones, Meyer, Slack, Vollmer, Barrett, Leach and Ostermann.)

Purpose: Extracorporeal membrane oxygenation (ECMO) use for severe coronavirus disease 2019 (COVID-19) patients has increased during the course of the pandemic. As uncertainty existed regarding patient's outcomes, early guidelines recommended against establishing new ECMO centers. We aimed to explore the epidemiology and outcomes of ECMO for COVID-19 related cardiopulmonary failure in five countries in the Middle East and India and to evaluate the results of ECMO in 5 new centers., Methods: This is a retrospective, multicenter international, observational study conducted in 19 ECMO centers in five countries in the Middle East and India from March 1, 2020, to September 30, 2020. We included patients with COVID-19 who received ECMO for refractory hypoxemia and severe respiratory acidosis with or without circulatory failure. Data collection included demographic data, ECMO-related specific data, pre-ECMO patient condition, 24 h post-ECMO initiation data, and outcome. The primary outcome was survival to home discharge. Secondary outcomes included mortality during ECMO, survival to decannulation, and outcomes stratified by center type., Results: Three hundred and seven COVID-19 patients received ECMO support during the study period, of whom 78 (25%) were treated in the new ECMO centers. The median age was 45 years (interquartile range IQR 37-52), and 81% were men. New center patients were younger, were less frequently male, had received higher PEEP, more frequently inotropes and prone positioning before ECMO and were less frequently retrieved from a peripheral center on ECMO. Survival to home discharge was 45%. In patients treated in new and established centers, survival was 55 and 41% (p = 0.03), respectively. Multivariable analysis retained only a SOFA score < 12 at ECMO initiation as associated with survival (odds ratio, OR 1.93 (95% CI 1.05-3.58), p = 0.034), but not treatment in a new center (OR 1.65 (95% CI 0.75-3.67))., Conclusions: During pandemics, ECMO may provide favorable outcomes in highly selected patients as resources allow. Newly formed ECMO centers with appropriate supervision of regional experts may have satisfactory results., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)