Search

Background: Postoperative hypoxemia and pulmonary complications remain a frequent event after on-pump cardiac surgery and mostly characterized by pulmonary atelectasis. Surfactant dysfunction or hyposecretion happens prior to atelectasis formation, and sigh represents the strongest stimulus for surfactant secretion. The role of sigh breaths added to conventional lung protective ventilation in reducing postoperative hypoxemia and pulmonary complications among cardiac surgery is unknown. Methods: The perioperative sigh ventilation in cardiac surgery (E-SIGHT) trial is a single-center, two-arm, randomized controlled trial. In total, 192 patients scheduled for elective cardiac surgery with cardiopulmonary bypass (CPB) and aortic cross-clamp will be randomized into one of the two treatment arms. In the experimental group, besides conventional lung protective ventilation, sigh volumes producing plateau pressures of 35 cmH2O (or 40 cmH2O for patients with body mass index > 35 kg/m2) delivered once every 6 min from intubation to extubation. In the control group, conventional lung protective ventilation without preplanned recruitment maneuvers is used. Lung protective ventilation (LPV) consists of low tidal volumes (6–8 mL/kg of predicted body weight) and positive end-expiratory pressure (PEEP) setting according to low PEEP/FiO2 table for acute respiratory distress syndrome (ARDS). The primary endpoint is time-weighted average SpO2/FiO2 ratio during the initial post-extubation hour. Main secondary endpoint is the severity of postoperative pulmonary complications (PPCs) computed by postoperative day 7. Discussion: The E-SIGHT trial will be the first randomized controlled trial to evaluate the impact of perioperative sigh ventilation on the postoperative outcomes after on-pump cardiac surgery. The trial will introduce and assess a novel perioperative ventilation approach to mitigate the risk of postoperative hypoxemia and PPCs in patients undergoing cardiac surgery. Also provide the basis for a future larger trial aiming at verifying the impact of sigh ventilation on postoperative pulmonary complications. Trial registration: ClinicalTrials.gov NCT06248320. Registered on January 30, 2024. Last updated February 26, 2024. [ABSTRACT FROM AUTHOR]

Background: There is accumulating evidence regarding the benefits of the 5-HT3 receptor antagonist ondansetron for the treatment of critical illness due to its potential anti-inflammatory effect. This study attempted to determine the potential targets and molecular mechanisms of ondansetron's action against critical illnesses. Methods: A bioinformatics analysis of network pharmacology was conducted to demonstrate screening targets and the signaling pathways of ondansetron action against the most common critical illnesses such as acute kidney injury (AKI), sepsis, and acute respiratory distress syndrome (ARDS). Experiments of LPS- stimulated rat neutrophilswith ondansetron treatmentwere conducted to further validate the relevant hypothesis. Results: A total of 198, 111, and 26 primary causal targets were identified fromthe data for the action of ondansetron against AKI, sepsis, and ARDS respectively. We found that the pathway of neutrophil extracellular traps (NETs) formation is statistically significantly involved in the action of ondansetron against these three critical illnesses. In the pathway of NETs formation, the common drug- disease intersection targets in these three critical illnesses were toll-like receptor 8(TLR8),mitogen-activated protein kinase-14 (MAPK14), nuclear factor kappa-B1 (NFKB1), neutrophil elastase (NE), andmyeloperoxidase (MPO). Considering these bioinformatics findings, we concluded that ondansetron anti-critical illness effects are mechanistically and pharmacologically implicated with suppression of neutrophils-associated inflammatory processes. It was also showed that after treatment of LPS-stimulated rat neutrophils with ondansetron, the key proteins NE, MPO, and Peptide Arginine Deaminase 4 (PAD4) in the NETs formation were significantly reduced, and the inflammatory factors IL-6, IL-1β, TNF-α, and chemokine receptor (CXCR4) were also significantly decreased. Conclusion: The excessive formation of NETsmay have important research value in the development and progression of critical illness. Ondansetron may reduce excessive inflammatory injury in critical diseases by reducing the formation of NETs via influencing the five targets: TLR8, NFKB1, MAPK14, NE, and MPO. Ondansetron and these primary predictive biotargets may potentially be used to treat critical illness in future clinical practice. [ABSTRACT FROM AUTHOR]

Mitochondria play a significant and varied role in inflammatory lung disorders. Mitochondria, known as the powerhouse of the cell because of their role in producing energy, are now recognized as crucial regulators of inflammation and immunological responses. Asthma, chronic obstructive pulmonary disease, and acute respiratory distress syndrome are characterized by complex interactions between immune cells, inflammatory substances, and tissue damage. Dysfunctional mitochondria can increase the generation of reactive oxygen species (ROS), triggering inflammatory pathways. Moreover, mitochondrial failure impacts cellular signaling, which in turn affects the expression of molecules that promote inflammation. In addition, mitochondria have a crucial role in controlling the behavior of immune cells, such as their activation and differentiation, which is essential in the development of inflammatory lung diseases. Their dynamic behavior, encompassing fusion, fission, and mitophagy, also impacts cellular responses to inflammation and oxidative stress. Gaining a comprehensive understanding of the intricate correlation between mitochondria and lung inflammation is essential in order to develop accurate treatment strategies. Targeting ROS generation, dynamics, and mitochondrial function may offer novel approaches to treating inflammatory lung diseases while minimizing tissue damage. Additional investigation into the precise contributions of mitochondria to lung inflammation will provide significant knowledge regarding disease mechanisms and potential therapeutic approaches. This review will focus on how mitochondria in the lung regulate these processes and their involvement in acute and chronic lung diseases. [ABSTRACT FROM AUTHOR]

The genome of the Nipah virus (NiV) encodes a variety of structural proteins linked to a diverse array of symptoms, including fevers, headaches, somnolence, and respiratory impairment. In instances of heightened severity, it can also invade the central nervous system (CNS), resulting in more pronounced problems. This work investigates the effects of NiV on the blood-brain barrier (BBB), the vital physiological layer responsible for safeguarding the CNS by regulating the passage of chemicals into the brain selectively. To achieve this, the researchers (MMJAO, AM and MNMD) searched a variety of databases for relevant articles on NiV and BBB disruption, looking for evidence of work on inflammation, immune response (cytokines and chemokines), tight junctions (TJs), and basement membranes related to NiV and BBB. Based on these works, it appears that the affinity of NiV for various receptors, including Ephrin-B2 and Ephrin-B3, has seen many NiV infections begin in the respiratory epithelium, resulting in the development of acute respiratory distress syndrome. The virus then gains entry into the circulatory system, offering it the potential to invade brain endothelial cells (ECs). NiV also has the ability to infect the leukocytes and the olfactory pathway, offering it a "Trojan horse" strategy. When NiV causes encephalitis, the CNS generates a strong inflammatory response, which makes the blood vessels more permeable. Chemokines and cytokines all have a substantial influence on BBB disruption, and NiV also has the ability to affect TJs, leading to disturbances in the structural integrity of the BBB. The pathogen's versatility is also shown by its capacity to impact multiple organ systems, despite particular emphasis on the CNS. It is of the utmost importance to comprehend the mechanisms by which NiV impacts the integrity of the BBB, as such comprehension has the potential to inform treatment approaches for NiV and other developing viral diseases. Nevertheless, the complicated pathophysiology and molecular pathways implicated in this phenomenon have offered several difficult challenges to researchers to date, underscoring the need for sustained scientific investigation and collaboration in the ongoing battle against this powerful virus. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) are attractive as a therapeutic modality in multiple disease conditions characterized by inflammation and vascular compromise. Logistically they are advantageous because they can be isolated from adult tissue sources, such as bone marrow (BM). The phase 2a START clinical trial determined BM-MSCs to be safe in patients with moderate-to-severe acute respiratory distress syndrome (ARDS). Herein, we examine a subset of the clinical doses of MSCs generated for the phase 2a START trial from three unique donors (1–3), where one of the donors' donated BM on two separate occasions (donor 3 and 3W). The main objective of this study was to correlate properties of the cells from the four lots with plasma biomarkers from treated patients and relevant to ARDS outcomes. To do this we evaluated MSC donor lots for (i) post-thaw viability, (ii) growth kinetics, (iii) metabolism, (iv) surface marker expression, (v) protein expression, (vi) immunomodulatory ability and (vii) their functional effects on regulating endothelial cell permeability. MSC-specific marker expression and protection of thrombin-challenged endothelial barrier permeability was similar among all four donor lots. Inter and intra-donor variability was observed in all the other in vitro assays. Furthermore, patient plasma ANG-2 and protein C levels at 6 hours post-transfusion were correlated to cell viability in an inter- and intra-donor dependent manner. These findings highlight the potential of donor dependent (inter-) and collection dependent (intra-) effects in patient biomarker expression. [ABSTRACT FROM AUTHOR]

The incidence of acute respiratory infections (ARinf), including SARS-CoV-2, in unvaccinated student rugby players during phases from complete lockdown during the COVID-19 pandemic to returning to competition is unknown. The aim of the study was to determine the incidence of ARinf (including SARS-CoV-2) during non- contact and contact phases during the COVID-19 pandemic to evaluate risk mitigation strategies. In this retrospective cohort study, 319 top tier rugby players from 17 universities completed an online questionnaire. ARinf was reported during 4 phases over 14 months (April 2020-May 2021): phase 1 (individual training), phase 2 (non-contact team training), phase 3 (contact team training) and phase 4 (competition). Incidence (per 1 000 player days) and Incidence Ratio (IR) for 'All ARinf', and subgroups (SARS-CoV-2; 'Other ARinf') are reported. Selected factors associated with ARinf were also explored. The incidence of 'All ARinf' (0.31) was significantly higher for SARS-CoV-2 (0.23) vs. 'Other ARinf' (0.08) (p < 0.01). The incidence of 'All ARinf (IR = 3.6; p < 0.01) and SARS-CoV-2 (IR = 4.2; p < 0.01) infection was significantly higher during contact (phases 3 + 4) compared with non-contact (phases 1 + 2). Demographics, level of sport, co-morbidities, allergies, influenza vaccination, injuries and lifestyle habits were not associated with ARinf incidence. In student rugby, contact phases are associated with a 3-4 times higher incidence of ARinf/SARS-CoV-2 compared to non-contact phases. Infection risk mitigation strategies in the contact sport setting are important. Data from this study serve as a platform to which future research on incidence of ARinf in athletes within contact team sports, can be compared. [ABSTRACT FROM AUTHOR]

Objective: This Study aims to investigate the risk factors of hypoglycemia in neonates through meta-analysis. Method: PubMed, Embase, Cochrane library, and Web of science databases were searched for case-control studies on risk factors for neonatal hypoglycemia. The search was done up to 1st October 2023 and Stata 15.0 was used for data analysis. Results: A total of 12 published studies were included, including 991 neonates in the hypoglycemic group and 4388 neonates in the non-hypoglycemic group. Meta-analysis results suggested caesarean section [OR = 1.90 95%CI (1.23, 2.92)], small gestational age[OR = 2.88, 95%CI (1.59, 5.20)], gestational diabetes [OR = 1.65, 95%CI (1.11, 2.46)], gestational hypertension[OR = 2,79, 95%CI (1.78, 4.35)] and respiratory distress syndrome[OR = 5.33, 95%CI (2.22, 12.84)] were risk factors for neonatal hypoglycemia. Conclusion: Based on the current study, we found that caesarean section, small gestational age, gestational diabetes, gestational hypertension, respiratory distress syndrome are risk factors for neonatal hypoglycemia. PROSPERO registration number: CRD42023472974. [ABSTRACT FROM AUTHOR]

Background: SARS-CoV-2 pneumonia can cause significant long-term radiological changes, even resembling pulmonary fibrosis. However, the risk factors for these long-term effects are unknown. This study aims to assess radiological abnormalities and their possible risk factors six months after hospital discharge due to COVID-19 pneumonia. Material and methods: This cross-sectional study in a tertiary hospital included adults admitted for COVID-19 pneumonia from March 2020 to February 2021, who underwent high-resolution computed tomography (HRCT) scans of the chest six months after hospital discharge. The primary outcome was radiological abnormalities on HRCT, while the main explanatory variables were drawn from the patient's medical history along with the disease course, analytical indicators, and the treatment received during admission. Results: The 189 included patients had a mean age of 61.5 years; 70.9% were male, and hypertension was the main comorbidity (45%). About two-thirds (67.2%) presented acute respiratory distress syndrome (ARDS). Most (97.9%) received systemic corticosteroid therapy, and 81% presented pathological findings on HRCT, most commonly ground glass (63.5%), followed by bronchial dilatation (36%) and subpleural bands (25.4%). The multivariable analysis showed that age was the main risk factor, associated with most radiological changes. Other factors were the duration of corticosteroid therapy for ground glass (adjusted odds ratio [aOR] 1.020) as well as a longer stay in the intensive care unit (ICU) (aOR 1.290) and high levels of IL-6 for bronchial dilation (aOR 1.002). Conclusion: Radiological involvement of the lungs six months after COVID-19 pneumonia is frequent, especially ground glass. Elderly patients with prolonged ICU admission and a significant inflammatory response measured by IL-6 are more likely to present worse radiological evolution and are candidates for radiological follow-up after COVID-19 pneumonia. [ABSTRACT FROM AUTHOR]

Background: Acute respiratory distress syndrome (ARDS) remains a significant challenge in critical care, with high mortality rates despite advancements in treatment. Venovenous extracorporeal membrane oxygenation (VV-ECMO) is employed as salvage therapy for refractory cases. However, some patients may continue to experience persistent severe hypoxemia despite being treated with VV-ECMO. To achieve this, moderate hypothermia and short-acting selective β1-blockers have been proposed. Methods: Using a swine model of severe ARDS treated with VV-ECMO, this study investigated the efficacy of moderate hypothermia or β-blockade in improving arterial oxygen saturation (SaO2) three hours after VV-ECMO initiation. Primary endpoints included the ratio of VV-ECMO flow to cardiac output and arterial oxygen saturation before VV-ECMO start (H0) and three hours after ECMO start (H3). Secondary safety criteria encompassed hemodynamics and oxygenation parameters. Results: Twenty-two male pigs were randomized into three groups: control (n = 6), hypothermia (n = 9) and β-blockade (n = 7). At H0, all groups demonstrated similar hemodynamic and respiratory parameters. Both moderate hypothermia and β-blockade groups exhibited a significant increase in the ratio of VV-ECMO flow to cardiac output at H3, resulting in improved SaO2. At H3, despite a decrease in oxygen delivery and consumption in the intervention groups compared to the control group, oxygen extraction ratios across groups remained unchanged and lactate levels were normal. Conclusions: In a swine model of severe ARDS treated with VV-ECMO, both moderate hypothermia and β-blockade led to an increase in the ratio of VV-ECMO flow to cardiac output resulting in improved arterial oxygen saturation without any impact on tissue perfusion. [ABSTRACT FROM AUTHOR]

Extracellular histones are crucial damage-associated molecular patterns involved in the development and progression of multiple critical and inflammatory diseases, such as sepsis, pancreatitis, trauma, acute liver failure, acute respiratory distress syndrome, vasculitis and arthritis. During the past decade, the physiopathologic mechanisms of histone-mediated hyperinflammation, endothelial dysfunction, coagulation activation, neuroimmune injury and organ dysfunction in diseases have been systematically elucidated. Emerging preclinical evidence further shows that anti-histone strategies with either their neutralizers (heparin, heparinoids, nature plasma proteins, small anion molecules and nanomedicines, etc.) or extracorporeal blood purification techniques can significantly alleviate histone-induced deleterious effects, and thus improve the outcomes of histone-related critical and inflammatory animal models. However, a systemic evaluation of the efficacy and safety of these histone-targeting therapeutic strategies is currently lacking. In this review, we first update our latest understanding of the underlying molecular mechanisms of histoneinduced hyperinflammation, endothelial dysfunction, coagulopathy, and organ dysfunction. Then, we summarize the latest advances in histone-targeting therapy strategies with heparin, anti-histone antibodies, histone-binding proteins or molecules, and histone-affinity hemoadsorption in pre-clinical studies. Finally, challenges and future perspectives for improving the clinical translation of histone-targeting therapeutic strategies are also discussed to promote better management of patients with histone-related diseases. [ABSTRACT FROM AUTHOR]

Background: By controlling hypercapnia, respiratory acidosis, and associated consequences, extracorporeal CO2 removal (ECCO2R) has the potential to facilitate ultra-protective lung ventilation (UPLV) strategies and to decrease injury from mechanical ventilation. We convened a meeting of European intensivists and nephrologists and used a modified Delphi process to provide updated insights into the role of ECCO2R in acute respiratory distress syndrome (ARDS) and to identify recommendations for a future randomized controlled trial. Results: The group agreed that lung protective ventilation and UPLV should have distinct definitions, with UPLV primarily defined by a tidal volume (VT) of 4–6 mL/kg predicted body weight with a driving pressure (ΔP) ≤ 14–15 cmH2O. Fourteen (93%) participants agreed that ECCO2R would be needed in the majority of patients to implement UPLV. Furthermore, 10 participants (majority, 63%) would select patients with PaO2:FiO2 > 100 mmHg (> 13.3 kPa) and 14 (consensus, 88%) would select patients with a ventilatory ratio of > 2.5–3. A minimum CO2 removal rate of 80 mL/min delivered by continuous renal support machines was suggested (11/14 participants, 79%) for this objective, using a short, double-lumen catheter inserted into the right internal jugular vein as the preferred vascular access. Of the participants, 14/15 (93%, consensus) stated that a new randomized trial of ECCO2R is needed in patients with ARDS. A ΔP of ≥ 14–15 cmH2O was suggested by 12/14 participants (86%) as the primary inclusion criterion. Conclusions: ECCO2R may facilitate UPLV with lower volume and pressures provided by the ventilator, while controlling respiratory acidosis. Since recent European Society of Intensive Care Medicine guidelines on ARDS recommended against the use of ECCO2R for the treatment of ARDS outside of randomized controlled trials, new trials of ECCO2R are urgently needed, with a ΔP of ≥ 14–15 cmH2O suggested as the primary inclusion criterion. [ABSTRACT FROM AUTHOR]

Background: Coronavirus disease 2019 originated in China and swiftly spread worldwide, posing a significant threat to public health. Caused by SARS-CoV-2, it manifests as a flu-like illness that can escalate to Acute Respiratory Distress Syndrome, potentially resulting in fatalities. In countries where HIV/Leishmania infantum is endemic, the occurrence of concurrent SARS-CoV-2/HIV/Leishmania infantum infections is a reality, prompting inquiries into appropriate clinical management. Case presentation: We present the case of a 48-year-old woman who was hospitalized for 36 days across three different hospitals in the state of Pernambuco, Brazil. She was diagnosed with SARS-CoV-2/HIV/L. infantum coinfection. The patient exhibited severe COVID-19 symptoms, including fever, productive cough, and dyspnea. Throughout her hospitalization, she experienced oxygen saturation levels of ≤ 93%, along with fluctuations in blood pressure, respiratory rate, and heart rate. Her blood tests revealed lymphopenia, leukopenia, and neutropenia, while laboratory results indicated abnormal levels of d-dimer, AST, ALT, lactate dehydrogenase, ferritin, and C-reactive protein. A computed tomography scan revealed 75% involvement of the lung parenchyma with patchy ground-glass opacities. Conclusion: Against all odds, the patient was discharged. The leukopenia associated with HIV/L. infantum may have played a decisive role. Further studies are necessary to better understand diagnostic strategies and clinical management measures for HIV/L. infantum coinfected patients who are susceptible to SARS-CoV-2 infection. [ABSTRACT FROM AUTHOR]

Background: A combination of prone positioning (PP) and venovenous extracorporeal membrane oxygenation (VV-ECMO) is safe, feasible, and associated with potentially improved survival for severe acute respiratory distress syndrome (ARDS). However, whether ARDS patients, especially non-COVID-19 patients, placed in PP before VV-ECMO should continue PP after a VV-ECMO connection is unknown. This study aimed to test the hypothesis that early use of PP during VV-ECMO could increase the proportion of patients successfully weaned from ECMO support in severe ARDS patients who received PP before ECMO. Methods: In this prospective observational study, patients with severe ARDS who were treated with VV-ECMO were divided into two groups: the prone group and the supine group, based on whether early PP was combined with VV-ECMO. The proportion of patients successfully weaned from VV-ECMO and 60-day mortality were analyzed before and after propensity score matching. Results: A total of 165 patients were enrolled, 50 in the prone and 115 in the supine group. Thirty-two (64%) and 61 (53%) patients were successfully weaned from ECMO in the prone and the supine groups, respectively. The proportion of patients successfully weaned from VV-ECMO in the prone group tended to be higher, albeit not statistically significant. During PP, there was a significant increase in partial pressure of arterial oxygen (PaO2) without a change in ventilator or ECMO settings. Tidal impedance shifted significantly to the dorsal region, and lung ultrasound scores significantly decreased in the anterior and posterior regions. Forty-five propensity score-matched patients were included in each group. In this matched sample, the prone group had a higher proportion of patients successfully weaned from VV-ECMO (64.4% vs. 42.2%; P = 0.035) and lower 60-day mortality (37.8% vs. 60.0%; P = 0.035). Conclusions: Patients with severe ARDS placed in PP before VV-ECMO should continue PP after VV-ECMO support. This approach could increase the probability of successful weaning from VV-ECMO. Trial Registration: ClinicalTrials.Gov: NCT04139733. Registered 23 October 2019. [ABSTRACT FROM AUTHOR]

Type 2 alveolar epithelial (AT2) cells of the lung are fundamental in regulating alveolar inflammation in response to injury. Impaired mitochondrial long-chain fatty acid β-oxidation (mtLCFAO) in AT2 cells is assumed to aggravate alveolar inflammation in acute lung injury (ALI), yet the importance of mtLCFAO to AT2 cell function needs to be defined. Here we show that expression of carnitine palmitoyltransferase 1a (CPT1a), a mtLCFAO rate limiting enzyme, in AT2 cells is significantly decreased in acute respiratory distress syndrome (ARDS). In mice, Cpt1a deletion in AT2 cells impairs mtLCFAO without reducing ATP production and alters surfactant phospholipid abundance in the alveoli. Impairing mtLCFAO in AT2 cells via deleting either Cpt1a or Acadl (acyl-CoA dehydrogenase long chain) restricts alveolar inflammation in ALI by hindering the production of the neutrophilic chemokine CXCL2 from AT2 cells. This study thus highlights mtLCFAO as immunometabolism to injury in AT2 cells and suggests impaired mtLCFAO in AT2 cells as an anti-inflammatory response in ARDS. Impaired mitochondrial long-chain fatty acid β-oxidation (mtLCFAO) in type 2 alveolar epithelial (AT2) cells is thought to aggravate alveolar inflammation in acute lung injury. Here, the authors show that the mtLCFAO rate limiting enzyme CPT1a is decreased in AT2 cells in acute respiratory distress syndrome, highlighting the role of mtLCFAO in immunometabolism in this context. [ABSTRACT FROM AUTHOR]

Introduction: Acute Respiratory Distress Syndrome (ARDS) poses a significant health challenge due to its high incidence and mortality rates. The emergence of SARS-CoV-2 has added complexity, with evidence suggesting a correlation between COVID-19 induced ARDS and post-COVID symptoms. Understanding the underlying mechanisms of ARDS in COVID-19 patients is crucial for effective clinical treatment. Method: To investigate the potential role of ferroptosis in SARS-CoV-2 induced ARDS, we conducted a comprehensive analysis using bioinformatics methods. Datasets from the Gene Expression Omnibus (GEO) were utilized, focusing on COVID-19 patients with varying ARDS severity. We employed weighted gene co-expression network analysis (WGCNA), differential gene expression analysis, and single-cell sequencing to identify key genes associated with ferroptosis in ARDS. Hub genes were validated using additional GEO datasets and cell experiment. Result: The analysis discerned 916 differentially expressed genes in moderate/ severe ARDS patients compared to non-critical individuals. Weighted Gene Co-expression Network Analysis (WGCNA) unveiled two modules that exhibited a positive correlation with ARDS, subsequently leading to the identification of 15 hub genes associated with ferroptosis. Among the noteworthy hub genes were MTF1, SAT1, and TXN. Protein-protein interaction analysis, and pathway analysis further elucidated their roles. Immune infiltrating analysis highlighted associations between hub genes and immune cells. Validation in additional datasets confirmed the upregulation of MTF1, SAT1, and TXN in SARS-CoV-2-induced ARDS. This was also demonstrated by qRT-PCR results in the BEAS-2B cells vitro model, suggesting their potential as diagnostic indicators. Discussion: This study identifies MTF1, SAT1, and TXN as hub genes associated with ferroptosis in SARS-CoV-2-induced ARDS. These findings provide novel insights into the molecular mechanisms underlying ARDS in COVID-19 patients and offer potential targets for immune therapy and targeted treatment. Further experimental validation is warranted to solidify these findings and explore therapeutic interventions for ARDS in the context of COVID-19. [ABSTRACT FROM AUTHOR]

Introduction: The acute respiratory distress syndrome (ARDS) is a common complication of severe COVID-19 and contributes to patient morbidity and mortality. ARDS is a heterogeneous syndrome caused by various insults, and results in acute hypoxemic respiratory failure. Patients with ARDS from COVID-19 may represent a subgroup of ARDS patients with distinct molecular profiles that drive disease outcomes. Here, we hypothesized that longitudinal transcriptomic analysis may identify distinct dynamic pathobiological pathways during COVID-19 ARDS. Methods: We identified a patient cohort from an existing ICU biorepository and established three groups for comparison: 1) patients with COVID-19 ARDS that survived hospitalization (COVID survivors, n = 4), 2) patients with COVID-19 ARDS that did not survive hospitalization (COVID non-survivors, n = 5), and 3) patients with ARDS from other causes as a control group (ARDS controls, n = 4). RNA was isolated from peripheral blood mononuclear cells (PBMCs) at 4 time points (Days 1, 3, 7, and 10 following ICU admission) and analyzed by bulk RNA sequencing. Results: We first compared transcriptomes between groups at individual timepoints and observed significant heterogeneity in differentially expressed genes (DEGs). Next, we utilized the likelihood ratio test to identify genes that exhibit different patterns of change over time between the 3 groups and identified 341 DEGs across time, including hemoglobin subunit alpha 2 (HBA1, HBA2), hemoglobin subunit beta (HBB), von Willebrand factor C and EGF domains (VWCE), and carbonic anhydrase 1 (CA1), which all demonstrated persistent upregulation in the COVID non-survivors compared to COVID survivors. Of the 341 DEGs, 314 demonstrated a similar pattern of persistent increased gene expression in COVID non-survivors compared to survivors, associated with canonical pathways of iron homeostasis signaling, erythrocyte interaction with oxygen and carbon dioxide, erythropoietin signaling, heme biosynthesis, metabolism of porphyrins, and iron uptake and transport. Discussion: These findings describe significant differences in gene regulation during patient ICU course between survivors and non-survivors of COVID-19 ARDS. We identified multiple pathways that suggest heme and red blood cell metabolism contribute to disease outcomes. This approach is generalizable to larger cohorts and supports an approach of longitudinal sampling in ARDS molecular profiling studies, which may identify novel targetable pathways of injury and resolution. [ABSTRACT FROM AUTHOR]

Background: Ventilation management may differ between COVID–19 ARDS (COVID–ARDS) patients and patients with pre–COVID ARDS (CLASSIC–ARDS); it is uncertain whether associations of ventilation management with outcomes for CLASSIC–ARDS also exist in COVID–ARDS. Methods: Individual patient data analysis of COVID–ARDS and CLASSIC–ARDS patients in six observational studies of ventilation, four in the COVID–19 pandemic and two pre–pandemic. Descriptive statistics were used to compare epidemiology and ventilation characteristics. The primary endpoint were key ventilation parameters; other outcomes included mortality and ventilator–free days and alive (VFD–60) at day 60. Results: This analysis included 6702 COVID–ARDS patients and 1415 CLASSIC–ARDS patients. COVID–ARDS patients received lower median VT (6.6 [6.0 to 7.4] vs 7.3 [6.4 to 8.5] ml/kg PBW; p < 0.001) and higher median PEEP (12.0 [10.0 to 14.0] vs 8.0 [6.0 to 10.0] cm H2O; p < 0.001), at lower median ΔP (13.0 [10.0 to 15.0] vs 16.0 [IQR 12.0 to 20.0] cm H2O; p < 0.001) and higher median Crs (33.5 [26.6 to 42.1] vs 28.1 [21.6 to 38.4] mL/cm H2O; p < 0.001). Following multivariable adjustment, higher ΔP had an independent association with higher 60–day mortality and less VFD–60 in both groups. Higher PEEP had an association with less VFD–60, but only in COVID–ARDS patients. Conclusions: Our findings show important differences in key ventilation parameters and associations thereof with outcomes between COVID–ARDS and CLASSIC–ARDS. Trial registration: Clinicaltrials.gov (identifier NCT05650957), December 14, 2022. [ABSTRACT FROM AUTHOR]

Background: This study aimed to evaluate the role of platelet count (PLT) in the prognosis of patients with acute respiratory distress syndrome (ARDS). Methods: The data were extracted from the Medical Information Mart for Intensive Care database (version 2.2). Patients diagnosed with ARDS according to criteria from Berlin Definition and had the platelet count (PLT) measured within the first day after intensive care unit admission were analyzed. Based on PLT, ARDS patients were divided into four groups: PLT ≤ 100 × 109/L, PLT 101–200 × 109/L, PLT 201–300 × 109/L, and PLT > 300 × 109/L. The primary outcome was 28-day mortality. Survival probabilities were analyzed using Kaplan–Meier. Furthermore, the association between PLT and mortality in ARDS patients was assessed using a univariate and multivariable Cox proportional hazards model. Results: Overall, the final analysis included 3,207 eligible participants with ARDS. According to the Kaplan–Meier curves for 28-day mortality of PLT, PLT ≤ 100 × 109/L was associated with a higher incidence of mortality (P = 0.001), the same trends were observed in the 60-day (P = 0.001) and 90‐day mortality (P = 0.001). In the multivariate model adjusted for the potential factors, the adjusted hazard ratio at PLT 101–200 × 109/L group, PLT 201–300 × 109/L, and PLT > 300 × 109/L was 0.681 [95% confidence interval (CI): 0.576–0.805, P < 0.001], 0.733 (95% CI: 0.604–0.889, P = 0.002), and 0.787 (95% CI: 0.624–0.994, P = 0.044) compared to the reference group (PLT ≤ 100 × 109/L), respectively. Similar relationships between the PLT ≤ 100 × 109/L group and 28-day mortality were obtained in most subgroups. Conclusion: PLT appeared to be an independent predictor of mortality in critically ill patients with ARDS. [ABSTRACT FROM AUTHOR]

Background: Acute respiratory distress syndrome (ARDS) after cardiac surgery is a severe respiratory complication with high mortality and morbidity. Traditional clinical approaches may lead to under recognition of this heterogeneous syndrome, potentially resulting in diagnosis delay. This study aims to develop and external validate seven machine learning (ML) models, trained on electronic health records data, for predicting ARDS after cardiac surgery. Methods: This multicenter, observational cohort study included patients who underwent cardiac surgery in the training and testing cohorts (data from Nanjing First Hospital), as well as those patients who had cardiac surgery in a validation cohort (data from Shanghai General Hospital). The number of important features was determined using the sliding windows sequential forward feature selection method (SWSFS). We developed a set of tree-based ML models, including Decision Tree, GBDT, AdaBoost, XGBoost, LightGBM, Random Forest, and Deep Forest. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and Brier score. The SHapley Additive exPlanation (SHAP) techinque was employed to interpret the ML model. Furthermore, a comparison was made between the ML models and traditional scoring systems. ARDS is defined according to the Berlin definition. Results: A total of 1996 patients who had cardiac surgery were included in the study. The top five important features identified by the SWSFS were chronic obstructive pulmonary disease, preoperative albumin, central venous pressure_T4, cardiopulmonary bypass time, and left ventricular ejection fraction. Among the seven ML models, Deep Forest demonstrated the best performance, with an AUC of 0.882 and a Brier score of 0.809 in the validation cohort. Notably, the SHAP values effectively illustrated the contribution of the 13 features attributed to the model output and the individual feature's effect on model prediction. In addition, the ensemble ML models demonstrated better performance than the other six traditional scoring systems. Conclusions: Our study identified 13 important features and provided multiple ML models to enhance the risk stratification for ARDS after cardiac surgery. Using these predictors and ML models might provide a basis for early diagnostic and preventive strategies in the perioperative management of ARDS patients. [ABSTRACT FROM AUTHOR]

Xanthoxylin, a bioactive phenolic compound extracted from the traditional herbal medicine Penthorum Chinense Pursh, is renowned for its anti-inflammatory effects. While previous studies have highlighted the anti-inflammatory and antioxidant properties of Xanthoxylin, its precise mechanisms, particularly concerning immune response and organ protection, remain underexplored. This study aimed to elucidate the effects of Xanthoxylin on inflammation and associated signaling pathways in a mouse model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). ALI was induced via intratracheal administration of LPS, followed by intraperitoneal injections of Xanthoxylin at doses of 1, 2.5, 5, and 10 mg/kg, administered 30 min post-LPS exposure. Lung tissues were harvested for analysis 6 h after LPS challenge. Xanthoxylin treatment significantly mitigated lung tissue damage, pathological alterations, immune cell infiltration, and the production of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Additionally, Xanthoxylin modulated the expression of key proteins in the protein kinase B (Akt)/hypoxia-inducible factor 1-alpha (HIF-1α)/nuclear factor-kappa B (NF-κB) signaling pathway, as well as nuclear factor erythroid 2-related factor 2 (Nrf2) and oxidative markers such as superoxide dismutase (SOD) and malondialdehyde (MDA) in the context of LPS-induced injury. This study demonstrates that Xanthoxylin exerts protective and anti-inflammatory effects by down-regulating and inhibiting the Akt/HIF-1α/NF-κB pathways, suggesting its potential as a therapeutic target for the prevention and treatment of ALI or acute respiratory distress syndrome (ARDS). [ABSTRACT FROM AUTHOR]

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and H1N1 viruses are inflammatory lung pathogens that can lead to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). ALI/ARDS are still life-threatening diseases in critically ill patients with 30–40% mortality in the last decade. Currently, there are no laboratory tests for the early diagnosis or prognosis of ALI/ARDS. Club cell secretory protein (CC16) has been investigated as a potential biomarker of lung epithelial damage in various lung diseases. In this study, we evaluated whether plasma CC16 reflects the severity of COVID-19 and H1N1 infections. The plasma CC16 levels showed no significant differences between H1N1 and COVID-19 groups (p = 0.09). Among all subjects, CC16 levels were significantly higher in non-survivors than in survivors (p = 0.001). Upon the area under the receiver operating characteristic (AUROC) analysis, CC16 had an acceptable value to distinguish survivors and non-survivors (p = 0.002). In the COVID-19 group, plasma CC16 levels moderately correlated with the Acute Physiology and Chronic Health Evaluation II (APACHE II) score (r = 0.374, p = 0.003) and Sequential Organ Failure Assessment (SOFA) score (r = 0.474, p < 0.001). In the H1N1 group, a positive correlation was observed between the CC16 levels and hospital length of stay (r = 0.311, p = 0.022). Among all the patients, weak correlations between plasma CC16 levels with the SOFA score (r = 0.328, p < 0.001) and hospital length of stay (r = 0.310, p < 0.001) were observed. Thus, circulating CC16 might reflect the severity of COVID-19 and H1N1 infections. [ABSTRACT FROM AUTHOR]

Background: This study aims to evaluate the association of metabolic syndrome (MetS) with the risk of all-cause mortality in elderly patients with acute respiratory distress syndrome (ARDS). Methods: Elderly ARDS patients (≥ 65 years) enrolled from our hospital between January 2018 and July 2023 were divided into the MetS group or the non-MetS group. The outcomes were 28-day and 90-day all-cause mortality rates in the total population and two subgroups stratified by age (65–75 years and ≥ 75 years). Multivariate Cox regression was employed to assess the association of MetS with all-cause mortality, after controlling for potential cofounding factors. Results: A total of 946 patients were divided into the MetS group (n = 410) or the non-MetS group (n = 536). The 28-day and 90-day all-cause mortality rates were significantly higher for MetS group compared to non-MetS group in the total population and two subgroups (all P < 0.01). Multivariate Cox regression indicated that MetS was significantly associated with a higher risk of 90-day all-cause mortality in the total population (HR = 1.62, 95% CI: 1.22–2.15; P < 0.01), and subgroups of patients aged 65–75 years (HR = 1.52, 95% CI: 1.04–2.21; P = 0.03) and ≥ 75 years (HR = 1.90, 95% CI: 1.23–2.94; P < 0.01). Moreover, with each MetS criterion added from 0 to 1 to 2, 3, and 4 of 4 criteria, both 28-day and 90-day all-cause mortality rates significantly increased (both P < 0.01). Conclusion: MetS was associated with higher risks of 28-day and 90-day all-cause mortality in elderly patients with ARDS. [ABSTRACT FROM AUTHOR]

Severe COVID-19 cases often progress to life-threatening conditions such as acute respiratory distress syndrome (ARDS), sepsis, and multiple organ dysfunction syndrome (MODS). Gelsolin (GSN), an actin-binding protein with anti-inflammatory and immunomodulatory properties, is a promising therapeutic target for severe COVID-19. Plasma GSN levels are significantly decreased in critical illnesses, including COVID-19, correlating with dysregulated immune responses and poor outcomes. GSN supplementation may mitigate acute lung injury, ARDS, and sepsis, which share pathophysiological features with severe COVID-19, by scavenging actin, modulating cytokine production, enhancing macrophage phagocytosis, and stabilizing the alveolar-capillary barrier. Preliminary data indicate that recombinant human plasma GSN improves oxygenation and lung function in severe COVID-19 patients with ARDS. Although further research is needed to optimize GSN therapy, current evidence supports its potential to mitigate severe consequences of COVID-19 and improve patient outcomes. This review provides a comprehensive analysis of the biological characteristics, mechanisms, and therapeutic value of GSN in severe COVID-19. [ABSTRACT FROM AUTHOR]

Acute respiratory distress syndrome (ARDS) has a fibroproliferative phase that may be followed by pulmonary fibrosis. Pulmonary fibrosis following COVID-19 pneumonia has been described at autopsy and following lung transplantation. We hypothesized that protein mediators of tissue remodeling and monocyte chemotaxis are elevated in the plasma and endotracheal aspirates of critically ill patients with COVID-19 who subsequently develop features of pulmonary fibroproliferation. We enrolled COVID-19 patients admitted to the ICU with hypoxemic respiratory failure. (n = 195). Plasma was collected within 24h of ICU admission and at 7d. In mechanically ventilated patients, endotracheal aspirates (ETA) were collected. Protein concentrations were measured by immunoassay. We tested for associations between protein concentrations and respiratory outcomes using logistic regression adjusting for age, sex, treatment with steroids, and APACHE III score. In a subset of patients who had CT scans during hospitalization (n = 75), we tested for associations between protein concentrations and radiographic features of fibroproliferation. Among the entire cohort, plasma IL-6, TNF-α, CCL2, and Amphiregulin levels were significantly associated with in-hospital mortality. In addition, higher plasma concentrations of CCL2, IL-6, TNF-α, Amphiregulin, and CXCL12 were associated with fewer ventilator-free days. We identified 20/75 patients (26%) with features of fibroproliferation. Within 24h of ICU admission, no measured plasma proteins were associated with a fibroproliferative response. However, when measured 96h-128h after admission, Amphiregulin was elevated in those that developed fibroproliferation. ETAs were not correlated with plasma measurements and did not show any association with mortality, ventilator-free days (VFDs), or fibroproliferative response. This cohort study identifies proteins of tissue remodeling and monocyte recruitment are associated with in-hospital mortality, fewer VFDs, and radiographic fibroproliferative response. Measuring changes in these proteins over time may allow for early identification of patients with severe COVID-19 at risk for fibroproliferation. [ABSTRACT FROM AUTHOR]

Introduction: Morbidly obese patients occasionally have respiratory problems owing to hypoventilation. Airway pressure release ventilation is one of the ventilation settings often used for respiratory management of acute respiratory distress syndrome. However, previous reports indicating that airway pressure release ventilation may become a therapeutic measure as ventilator management in morbid obesity with respiratory failure is limited. We report a case of markedly improved oxygenation in a morbidly obese patient after airway pressure release ventilation application. Case report: A 50s-year-old Asian man (body mass index 41 kg/m2) presented with breathing difficulties. The patient had respiratory failure with a PaO2/FIO2 ratio of approximately 100 and severe atelectasis in the left lung, and ventilator management was initiated. Although the patient was managed on a conventional ventilate mode, oxygenation did not improve. On day 11, we changed the ventilation setting to airway pressure release ventilation, which showed marked improvement in oxygenation with a PaO2/FIO2 ratio of approximately 300. We could reduce sedative medication and apply respiratory rehabilitation. The patient was weaned from the ventilator on day 29 and transferred to another hospital for further rehabilitation on day 31. Conclusion: Airway pressure release ventilation ventilator management in morbidly obese patients may contribute to improving oxygenation and become one of the direct therapeutic measures in the early stage of critical care. [ABSTRACT FROM AUTHOR]

Introduction: Sex-specific patterns in respiratory conditions, such as asthma, COPD, cystic fibrosis, obstructive sleep apnea, and idiopathic pulmonary fibrosis, have been previously documented. Animal models of acute lung injury (ALI) have offered insights into sex differences, with male mice exhibiting distinct lung edema and vascular leakage compared to female mice. Our lab has provided evidence that the chemoreflex is sensitized in male rats during the recovery from bleomycin-induced ALI, but whether sex-based chemoreflex changes occur post-ALI is not known. To bridge this gap, the current study employed the bleomycin-induced ALI animal model to investigate sex-based differences in chemoreflex activation during the recovery from ALI. Methods: ALI was induced using a single intra-tracheal instillation of bleomycin (bleo, 2.5 mg/Kg) (day 1). Resting respiratory frequency (fR) was measured at 1-2 days pre-bleo, day 7 (D7) post-bleo, and 1 month (1 mth) post-bleo. The chemoreflex responses to hypoxia (10% O2, 0%CO2) and normoxic-hypercapnia (21%O2, 5%CO2) were measured before bleo administration (pre-bleo) and 1 mth post-bleo using whole-body plethysmography. The apnea-hypopnea Index (AHI), post-sigh apneas, and sighs were measured at each time point. Results: Therewere no significant differences in resting fR between male and female rats at the pre-bleo time point or in the increase in resting fR at D7 post-bleo. At 1mth post-bleo, the resting fR was partially restored in both sexes but the recovery towards normal ranges of resting fR was significantly lower in male rats. The AHI, post-sigh apneas, and sighs were not different between male and female rats pre-bleo and 1mth post-bleo. However, at D7 post-bleo, themale rats exhibited a higher AHI than female rats. Bothmale and female rats exhibited a sensitized chemoreflex in response to hypoxia and normoxic-hypercapnia with no significant differences between sexes. Conclusion: A sex difference in resting ventilatory parameters occurs post ALI with a prolonged increase in resting fR and larger AHI in male rats. On the other hand, we did not find any sex differences in the chemoreflex sensitization that occurs at 1 mth post-bleo. This work contributes to a better understanding of sex-based variations in lung disorders. [ABSTRACT FROM AUTHOR]

Background: COVID-19 infections can result in severe acute respiratory distress syndrome (ARDS) requiring admission to the intensive care unit (ICU). Cardiovascular manifestation or exacerbation of cardiovascular diseases could be another complication. Cardiac arrhythmias including New-Onset Atrial Fibrillation (NOAF), have been observed in hospitalized patients with COVID-19 infections. In this analysis, we aimed to systematically compare the complications associated with NOAF in critically ill COVID-19 patients admitted to the ICU. Methods: MEDLINE, EMBASE, Web of Science, the Cochrane database, http://www.ClinicalTrials.gov, Google Scholar and Mendeley were searched for relevant publications based on COVID-19 patients with NOAF admitted to the ICU. Complications including in-hospital mortality, ICU mortality, patients requiring mechanical ventilation, acute myocardial infarction, acute kidney injury, renal replacement therapy and pulmonary embolism were assessed. This is a meta-analysis and the analytical tool which was used was the RevMan software version 5.4. Risk ratios (RR) and 95% confidence intervals (CIs) were used to represent the data post analysis. Results: In critically ill COVID-19 patients with NOAF admitted to the ICU, the risks of ICU mortality (RR: 1.39, 95% CI: 1.07 – 1.80; P = 0.01), in-hospital mortality (RR: 1.56, 95% CI: 1.20 – 2.04; P = 0.001), patients requiring mechanical ventilation (RR: 1.32, 95% CI: 1.04 – 1.66; P = 0.02) were significantly higher when compared to the control group without AF. Acute myocardial infarction (RR: 1.54, 95% CI: 1.31 – 1.81; P = 0.00001), the risk for acute kidney injury (RR: 1.31, 95% CI: 1.11 – 1.55; P = 0.002) and patients requiring renal replacement therapy (RR: 1.83, 95% CI: 1.60 – 2.09; P = 0.00001) were also significantly higher in patients with NOAF. Conclusions: Critically ill COVID-19 patients with NOAF admitted to the ICU were at significantly higher risks of developing complications and death compared to similar patients without AF. [ABSTRACT FROM AUTHOR]

Background & Objective: Coronavirus disease 2019 (COVID-19) claimed thousands of the lives during a limited period of time, but also enriched our scientific knowledge, especially regarding the respiratory pathogenesis and intensive care dynamics. This study was carried out to bridge the gap in the literature regarding the incidence, clinical features, and outcomes of spontaneous pneumothorax (SP) that develops during the course of COVID-19. Methodology: The population of this single-center retrospective study consisted of all critically ill adult patients who tested positive for COVID-19, developed SP, and were admitted to the intensive care units (ICUs) of Acibadem University School of Medicine, Training and Research Hospital, between March 21, 2020 and May 31, 2021. Detailed medical records, clinical findings, chest computed tomography (CT) scans, and X-ray images of critically ill COVID-19 patients complicated by SP were obtained and analyzed. Results: Of the 753 patients admitted to the ICUs during the study period, 600 tested positive for COVID-19 viral pneumonia. Of these patients, 549 met the diagnostic criteria for acute respiratory distress syndrome (ARDS), of whom 472 were treated with invasive mechanical ventilation (IMV) and 77 were treated without IMV. SP developed in a total of five (0.8%) patients, 4 (0.9%) of whom were on IMV support and 1 (1.2%) of whom was breathing spontaneously. Of these patients who developed SP, one patient on IMV support was female, and the remaining four were male. The median age of these five patients was 42 (33-64) years. Two (40%) of the five patients died in ICU. Conclusion: The actual incidence of COVID-19-related spontaneous pneumothorax is yet to be elucidated and may require a large scale, multi-center study. COVID-19-related spontaneous pneumothorax is similar to ARDS-related spontaneous pneumothorax without COVID-19 in terms of clinical features and outcomes, its risk of occurrence is higher. [ABSTRACT FROM AUTHOR]

Background and objective: COVID-19 has offered an opportunity to the clinicians to try and study various oxygenation enhancing maneuvers in the patients. These included lung protective measures and prone positioning of participants admitted to the ICU with acute respiratory distress syndrome. We aimed to identify the effects of early prone positioning on the length of stay, discharge rate, and frequency of tracheostomies in the ICU patients. Methodology: This retrospective study was conducted on critically ill patients needing mechanical ventilation with lung protective strategy, admitted to the Intensive Care Units of Al-Azhar University Hospitals between March 2020 to April 2022. All patients in the study were interpreted retrospectively by examining the patient's records. Group A (n = 39) included patients who had been early placed in prone positions within 24 h of intubation, and Group B (n = 31) included patients who had not been placed in prone positions. All patients received a lung protective strategy for ARDS. In both groups, PaO2, PaCO2, pH, SpO2, and PaO2/FiO2 ratio were checked initially and later every 24 h for 6 days. Data was evaluated for the total days of both hospital and ICU length of stay, number of successful discharges to home from the hospital, and the total number of tracheostomized patients. Results: After prone positioning, lower SOFA and APACHE II scores were noticed in the prone group. There was no significant difference in the rate of discharge between the two groups. We observed non-significant shorter hospital and ICU stays and higher frequency of tracheostomy procedures in the prone group. We noticed a significant improvement in PaO2/FiO2 ratios in the prone group starting from day 2 to day 6. We observed a significant improvement in PO2 in the prone group in comparison to the non-prone group. Conclusions: Early prone positioning of patients admitted to the ICU with acute respiratory distress syndrome during COVID-19 pandemic led to a significant improvement in both PaO2 and PaO2/FiO2 ratio with a non-significant decrease in both hospital and ICU length of stay as shown by the collected data over consecutive six days. [ABSTRACT FROM AUTHOR]

The MASS cohort is a study conducted in Chinese ICU settings that aims to investigate the role of the microbiome in severe pneumonia and host susceptibility. The cohort consists of 286 patients with severe pneumonia, and various biological samples are collected from them. The study highlights the need for further research to establish causality and explore the impact of environmental factors on severe pneumonia. The authors conclude that the cohort provides valuable insights into emerging pathogens, risk factors, and determinants of survival among ICU patients. [Extracted from the article]

Background: Leptospirosis, a zoonotic disease prevalent in tropical regions, often leads to severe complications such as Weil's disease and acute respiratory distress syndrome (ARDS). This pioneering meta-analysis investigated the role of corticosteroids in treating severe leptospirosis, addressing a critical gap in the current clinical knowledge. Methods: We systematically reviewed studies from PubMed and Scopus, focusing on randomized controlled trials and observational cohort studies involving adult patients diagnosed with leptospirosis. Five studies comprising 279 participants met the inclusion criteria. Results: Although some studies suggest potential benefits, particularly for pulmonary complications, the evidence remains inconclusive due to the limited number of studies and their methodological limitations. Notably, while four of the five reviewed studies indicated a possible positive role of corticosteroids, the single randomized controlled trial showed no significant benefit, highlighting the need for more robust research. Conclusions: While the current evidence provides a basis for potential benefits, it is not sufficient to make definitive clinical recommendations. Further research is essential to clarify the role of corticosteroids in the treatment of severe leptospirosis, with the aim of improving patient outcomes and guiding clinical practices effectively. [ABSTRACT FROM AUTHOR]

Even though much progress has been made to improve clinical outcomes, acute respiratory distress syndrome (ARDS) remains a significant cause of acute respiratory failure. Protective mechanical ventilation is the backbone of supportive care for these patients; however, there are still many unresolved issues in its setting. The primary goal of mechanical ventilation is to improve oxygenation and ventilation. The use of positive pressure, especially positive end-expiratory pressure (PEEP), is mandatory in this approach. However, PEEP is a double-edged sword. How to safely set positive end-inspiratory pressure has long been elusive to clinicians. We hereby propose a pressure–volume curve measurement-based method to assess whether injured lungs are recruitable in order to set an appropriate PEEP. For the most severe form of ARDS, extracorporeal membrane oxygenation (ECMO) is considered as the salvage therapy. However, the high level of medical resources required and associated complications make its use in patients with severe ARDS controversial. Our proposed protocol also attempts to propose how to improve patient outcomes by balancing the possible overuse of resources with minimizing patient harm due to dangerous ventilator settings. A recruitment-potential-oriented evaluation-based protocol can effectively stabilize hypoxemic conditions quickly and screen out truly serious patients. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the ability of the synthetic amphipathic helical peptide (SAHP), L-37pA, which mediates pathogen recognition and innate immune responses, to treat acute respiratory distress syndrome (ARDS) accompanied by diffuse alveolar damage (DAD) and chronic pulmonary fibrosis (PF). For the modeling of ARDS/DAD, male ICR mice were used. Intrabronchial instillation (IB) of 200 µL of inflammatory agents was performed by an intravenous catheter 20 G into the left lung lobe only, leaving the right lobe unaffected. Intravenous injections (IVs) of L-37pA, dexamethasone (DEX) and physiological saline (saline) were used as therapies for ARDS/DAD. L37pA inhibited the circulating levels of inflammatory cytokines, such as IL-8, TNFα, IL1α, IL4, IL5, IL6, IL9 and IL10, by 75–95%. In all cases, the computed tomography (CT) data indicate that L-37pA reduced lung density faster to −335 ± 23 Hounsfield units (HU) on day 7 than with DEX and saline, to −105 ± 29 HU and −23 ± 11 HU, respectively. The results of functional tests showed that L-37pA treatment 6 h after ARDS/DAD initiation resulted in a more rapid improvement in the physiological respiratory lung by 30–45% functions compared with the comparison drugs. Our data suggest that synthetic amphipathic helical peptide L-37pA blocked a cytokine storm, inhibited acute and chronic pulmonary inflammation, prevented fibrosis development and improved physiological respiratory lung function in the ARDS/DAD mouse model. We concluded that a therapeutic strategy using SAHPs targeting SR-B receptors is a potential novel effective treatment for inflammation-induced ARDS, DAD and lung fibrosis of various etiologies. [ABSTRACT FROM AUTHOR]

Acute respiratory distress syndrome (ARDS) occurs as an acute onset condition, and patients present with diffuse alveolar damage, refractory hypoxemia, and non-cardiac pulmonary edema. ARDS progresses through an initial exudative phase, an inflammatory phase, and a final fibrotic phase. Pirfenidone, a powerful anti-fibrotic agent, is known as an agent that inhibits the progression of fibrosis in idiopathic pulmonary fibrosis. In this study, we studied the treatment efficiency of pirfenidone on lipopolysaccharide (LPS) and bleomycin-induced ARDS using rats. The ARDS rat model was created by the intratracheal administration of 3 mg/kg LPS of and 3 mg/kg of bleomycin dissolved in 0.2 mL of normal saline. The pirfenidone treatment group was administered 100 or 200 mg/kg of pirfenidone dissolved in 0.5 mL distilled water orally 10 times every 2 days for 20 days. The administration of LPS and bleomycin intratracheally increased lung injury scores and significantly produced pro-inflammatory cytokines. ARDS induction increased the expressions of transforming growth factor (TGF)-β1/Smad-2 signaling factors. Additionally, matrix metalloproteinase (MMP)-9/tissue inhibitor of metalloproteinase (TIMP)-1 imbalance occurred, resulting in enhanced fibrosis-related factors. Treatment with pirfenidone strongly suppressed the expressions of TGF-β1/Smad-2 signaling factors and improved the imbalance of MMP-9/TIMP-1 compared to the untreated group. These effects led to a decrease in fibrosis factors and pro-inflammatory cytokines, promoting the recovery of damaged lung tissue. These results of this study showed that pirfenidone administration suppressed inflammation and fibrosis in the ARDS animal model. Therefore, pirfenidone can be considered a new early treatment for ARDS. [ABSTRACT FROM AUTHOR]

Background: Airway pressure release ventilation (APRV) has become increasingly popular for the management of acute respiratory distress syndrome (ARDS); however, its clinical impact remains a topic of debate. Furthermore, there is a gap between the guidelines and the actual clinical practices in mechanical ventilation management for ARDS. This survey aimed to explore the utilization of APRV and mechanical ventilation strategies for ARDS in Chinese intensive care unit (ICU) clinicians. Methods: A comprehensive 34‐item survey was distributed online platforms amongst ICU clinicians across mainland China from June to August 2019. Results: A total of 420 valid responses were collected, with 57.4% (241) originating from academic hospitals and 42.6% (179) from non‐academic hospitals. Of the respondents, 98.6% (414) recognized the significance of low tidal volume ventilation for ARDS prognosis, 85.2% adhered to a tidal volume below 8 mL/kg predicted body weight, and most (46.4%) selected the initial positive end‐expiratory pressure within the range of 5–10 cmH2O based on experience. Among the respondents, 62.1% (261) reported familiarity with APRV and 41.9% (176) had implemented APRV. Of those who had utilized APRV, 93.2% (164) believed in its effectiveness for ARDS patients and 69.3% (122) advocated for early application of APRV. Substantial variations were noted regarding APRV initiation settings and the preservation of spontaneous breathing during APRV. Academic hospitals exhibited higher usage rates of lung recruitment, neuromuscular blockade, prone ventilation, and acquaintance with and utilization of APRV compared to non‐academic hospitals (all p values ≤ 0.001). Conclusions: Our findings highlight opportunities for improvement in mechanical ventilation management for ARDS, particularly in non‐academic hospitals. Additionally, a significant proportion of clinicians demonstrated limited knowledge of APRV, and there was a lack of consensus on its application. Further training and larger‐scale clinical trials are required to validate the efficacy and utilization of APRV in managing ARDS. [ABSTRACT FROM AUTHOR]

Invasive fusariosis can be life-threatening, especially in immunocompromised patients who require intensive care unit (ICU) admission. We conducted a multicenter retrospective study to describe clinical and biologic characteristics, patient outcomes, and factors associated with death and response to antifungal therapy. We identified 55 patients with invasive fusariosis from 16 ICUs in France during 2002-2020. The mortality rate was high (56%). Fusariosis-related pneumonia occurred in 76% of patients, often leading to acute respiratory failure. Factors associated with death included elevated sequential organ failure assessment score at ICU admission or history of allogeneic hematopoietic stem cell transplantation or hematologic malignancies. Neither voriconazole treatment nor disseminated fusariosis were strongly associated with response to therapy. Invasive fusariosis can lead to multiorgan failure and is associated with high mortality rates in ICUs. Clinicians should closely monitor ICU patients with a history of hematologic malignancies or stem cell transplantation because of higher risk for death. [ABSTRACT FROM AUTHOR]

Background: Severe bacterial infections can trigger acute lung injury (ALI) and acute respiratory distress syndrome, with bacterial pathogen‐associated molecular patterns (PAMPs) exacerbating the inflammatory response, particularly in COVID‐19 patients. Cyclic‐di‐GMP (CDG), one of the PAMPs, is synthesized by various Gram‐positve and Gram‐negative bacteria. Previous studies mainly focused on the inflammatory responses triggered by intracellular bacteria‐released CDG. However, how extracellular CDG, which is released by bacterial autolysis or rupture, activates the inflammatory response remains unclear. Methods: The interaction between extracellular CDG and myeloid differentiation protein 2 (MD2) was investigated using in vivo and in vitro models. MD2 blockade was achieved using specific inhibitor and genetic knockout mice. Site‐directed mutagenesis, co‐immunoprecipitation, SPR and Bis‐ANS displacement assays were used to identify the potential binding sites of MD2 on CDG. Results: Our data show that extracellular CDG directly interacts with MD2, leading to activation of the TLR4 signalling pathway and lung injury. Specific inhibitors or genetic knockout of MD2 in mice significantly alleviated CDG‐induced lung injury. Moreover, isoleucine residues at positions 80 and 94, along with phenylalanine at position 121, are essential for the binding of MD2 to CDG. Conclusion: These results reveal that extracellular CDG induces lung injury through direct interaction with MD2 and activation of the TLR4 signalling pathway, providing valuable insights into bacteria‐induced ALI mechanisms and new therapeutic approaches for the treatment of bacterial co‐infection in COVID‐19 patients. [ABSTRACT FROM AUTHOR]

[Display omitted] • Neutrophilic inflammation is a critical pathogenic hallmark in ARDS. • Ribociclib, a clinically-used CDK4/6 inhibitor, acts as a novel PDE4 inhibitor to regulate neutrophilic inflammation. • Ribociclib shows therapeutic potential in ARDS. • The drug repurposing of ribociclib provides a promising opportunity for neutrophil-associated diseases, including ARDS. Overwhelming neutrophil activation and oxidative stress significantly contribute to acute respiratory distress syndrome (ARDS) pathogenesis. However, the potential of repurposing ribociclib, a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor used clinically in cancer treatment, for treating neutrophilic ARDS remains uncertain. This study illustrated the ability and underlying mechanism of ribociclib for treating ARDS and neutrophilic inflammation. Primary human neutrophils were used to determine the therapeutic effects of ribociclib on respiratory bursts, chemotactic responses, and inflammatory signaling. In vitro and silico analyses were performed to determine the underlying molecular mechanisms. The potential of ribociclib repurposing was evaluated using an in vivo ARDS model in lipopolysaccharide (LPS)-primed mice. We found that treatment using ribociclib markedly limited overabundant oxidative stress (reactive oxygen species [ROS]) production and chemotactic responses (integrin levels and adhesion) in activated human neutrophils. Ribociclib was also shown to act as a selective inhibitor of phosphodiesterase 4 (PDE4), thereby promoting the cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway, leading to the inhibition of extracellular signal-regulated kinase (ERK), c-Jun N -terminal kinase (JNK) phosphorylation, and calcium influx. Notably, prophylactic administration and post-treatment with ribociclib ameliorated neutrophil infiltration, lung inflammation, accumulation of oxidative stress, pulmonary destruction, and mortality in mice with LPS-induced ARDS. We demonstrated for the first time that ribociclib serves as a novel PDE4 inhibitor for treating neutrophilic inflammation and ARDS. The repurposing ribociclib and targeting neutrophilic PDE4 offer a potential off-label alternative for treating lung lesions and other inflammatory conditions. [ABSTRACT FROM AUTHOR]

Background: Sepsis is an uncontrolled systemic inflammatory response to an infection that can result in acute failure of the function of the lung called acute respiratory distress syndrome. Leukocyte recruitment is an important hallmark of acute lung failure in patients with sepsis. Endothelial cells (EC) participate in this process by facilitating tethering, rolling, adhesion, and transmigration of leukocytes via adhesion molecules on their cell surface. In in vivo studies, endothelial nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 and mitogen-activated protein kinase (MAPK) c-Jun intracellular signal transduction pathways were reported to regulate the expression of adhesion molecules. Methods: Mice underwent cecal ligation and puncture (CLP) to induce polymicrobial sepsis and were sacrificed at different time points up to 72 h after sepsis onset. Immunohistochemistry and reverse transcription–quantitative polymerase chain reaction (RT-qPCR) analyses were used to determine the kinetics of nuclear localization of p65 and c-Jun in EC, expression and location of adhesion molecules E-selectin and vascular cell adhesion molecule 1 (VCAM-1). Furthermore, the extent and location of leukocyte recruitment were assessed based on Ly6G staining of neutrophils, cluster determinant (CD) 3 staining of T lymphocytes, and CD68 staining of macrophages. Results: In all pulmonary microvascular beds, we identified p65 and c-Jun nuclear accumulation in a subset of endothelial cells within the first 24 h after CLP-sepsis initiation. E-selectin protein was expressed in a subset of microvessels at 4 and 7 h after sepsis initiation, while VCAM-1 was expressed in a scattered pattern in alveolar tissue and microvessels, without discernible changes during sepsis development. CLP-induced sepsis predominantly promoted the accumulation of neutrophils and T lymphocytes 4 and 7 h after disease onset. Neutrophil accumulation occurred in all pulmonary microvascular beds, while T lymphocytes were present in alveolar tissue and postcapillary venules. Taken together, nuclear localization of p65 and c-Jun in EC and neutrophil recruitment could be associated with induced E-selectin expression in the pulmonary microvessels in CLP-septic mice at the early stage of the disease. In alveolar capillaries, on the other hand, activation of these molecular pathways and leukocyte accumulation occurred in the absence of E-selectin or VCAM-1. Conclusions: Endothelial activation and leukocyte recruitment in sepsis-induced lung injury are regulated by multiple, heterogeneously controlled mechanisms, which vary depending on the type of microvascular bed involved. [ABSTRACT FROM AUTHOR]

Acute respiratory distress syndrome (ARDS) is a critical illness in critically unwell patients, characterized by refractory hypoxemia and shock. This study evaluates an early detection tool and investigates the relationship between hypoxia and circulatory shock in ARDS, to improve diagnostic precision and therapy customization. We used a porcine model, inducing ARDS with mechanical ventilation and intratracheal plus intravenous lipopolysaccharide (LPS) injection. Hemodynamic changes were monitored using an Acumen IQ sensor and a ForeSight Elite sensor connected to the HemoSphere platform. We evaluated tissue damage, inflammatory response, and hypoxia-inducible factor (HIF) alterations using enzyme-linked immunosorbent assay and immunohistochemistry. The results showed severe hypotension and increased heart rates post-LPS exposure, with a notable rise in the hypotension prediction index (HPI) during acute lung injury (p = 0.024). Tissue oxygen saturation dropped considerably in the right brain region. Interestingly, post-injury HIF-2α levels were lower at the end of the experiment. Our findings imply that the HPI can effectively predict ARDS-related hypotension. HIF expression levels may serve as possible markers of rapid ARDS progression. Further research should be conducted on the clinical value of this novel approach in critical care, as well as the relationship between the HIF pathway and ARDS-associated hypotension. [ABSTRACT FROM AUTHOR]

Objectives: To identify the prevalence and associated factors of cognitive dysfunction, 1 year after ICU discharge, among adult patients, and it´s relation with quality of life. Methods: Multicenter, prospective cohort study including ICUs of 10 tertiary hospitals in Brazil, between May 2014 and December 2018. The patients included were 452 adult ICU survivors (median age 60; 47.6% women) with an ICU stay greater than 72 h. Results: At 12 months after ICU discharge, a Montreal Cognitive Assessment (tMOCA) telephone score of less than 12 was defined as cognitive dysfunction. At 12 months, of the 452 ICU survivors who completed the cognitive evaluation 216 (47.8%) had cognitive dysfunction. In multivariable analyses, the factors associated with long-term (1-year) cognitive dysfunction were older age (Prevalence Ratio–PR = 1.44, P < 0.001), absence of higher education (PR = 2.81, P = 0.005), higher comorbidities on admission (PR = 1.089; P = 0.004) and delirium (PR = 1.13, P < 0.001). Health-related Quality of life (HRQoL), assessed by the mental and physical dimensions of the SF-12v2, was significantly better in patients without cognitive dysfunction (Mental SF-12v2 Mean difference = 2.54; CI 95%, − 4.80/− 0.28; p = 0.028 and Physical SF-12v2 Mean difference = − 2.85; CI 95%, − 5.20/− 0.50; P = 0.018). Conclusions: Delirium was found to be the main modifiable predictor of long-term cognitive dysfunction in ICU survivors. Higher education consistently reduced the probability of having long-term cognitive dysfunction. Cognitive dysfunction significantly influenced patients' quality of life, leading us to emphasize the importance of cognitive reserve for long-term prognosis after ICU discharge. [ABSTRACT FROM AUTHOR]

The secreted phospholipase A2 (sPLA2) isoform, sPLA2-IIA, has been implicated in a variety of diseases and conditions, including bacteremia, cardiovascular disease, COVID-19, sepsis, adult respiratory distress syndrome, and certain cancers. Given its significant role in these conditions, understanding the regulatory mechanisms impacting its levels is crucial. Genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs), including rs11573156, that are associated with circulating levels of sPLA2-IIA. The work in the manuscript leveraged 4 publicly available datasets to investigate the mechanism by which rs11573156 influences sPLA2-IIA levels via bioinformatics and modeling analysis. Through genotype-tissue expression (GTEx), 234 expression quantitative trait loci (eQTLs) were identified for the gene that encodes for sPLA2-IIA, PLA2G2A. SNP2TFBS was used to ascertain the binding affinities between transcription factors (TFs) to both the reference and alternative alleles of identified eQTL SNPs. Subsequently, candidate TF-SNP interactions were cross-referenced with the ChIP-seq results in matched tissues from ENCODE. SP1-rs11573156 emerged as the significant TF-SNP pair in the liver. Further analysis revealed that the upregulation of PLA2G2A transcript levels through the rs11573156 variant was likely affected by tissue SP1 protein levels. Using an ordinary differential equation based on Michaelis-Menten kinetic assumptions, we modeled the dependence of PLA2G2A transcription on SP1 protein levels, incorporating the SNP influence. Collectively, our analysis strongly suggests that the difference in the binding dynamics of SP1 to different rs11573156 alleles may underlie the allele-specific PLA2G2A expression in different tissues, a mechanistic model that awaits future direct experimental validation. This mechanism likely contributes to the variation in circulating sPLA2-IIA protein levels in the human population, with implications for a wide range of human diseases. [ABSTRACT FROM AUTHOR]

Background: The survival benefit of venovenous extracorporeal membrane oxygenation (VV-ECMO) in adult patients with severe acute respiratory distress syndrome (ARDS) remains controversial. This study aimed to investigate the efficiency and potential prognostic factors of VV-ECMO for severe ARDS in adults by evaluating our institutional experience and results. Materials and methods: This research studied ARDS patients receiving VV-ECMO between June 2011 and May 2023. The inclusion criteria were PaO2/FiO2 < 100 mmHg at FiO2 of 1.0. Retrospective data was analyzed to identify factors associated with successful ECMO weaning and hospital discharge survival. Results: A total of 18 patients were included in this study, with 7 cases (38.9%) successfully weaned from ECMO and 5 cases (27.8%) surviving hospital discharge. The overall complication rate was 77.8%. After treatment with VV ECMO, there were statistically significant improvements in both PaO2 and PaCO2 (P < 0.05). Patients in the successful weaning group had a lower pTB value, less accumulative volume of sodium bicarbonate during ECMO, and lower accumulative volume of intravenous immunoglobulin in the hospital compared to the unsuccessful weaning group (all P < 0.05). Furthermore, compared to the non-survivors, the survivors had less severe acidosis, higher mean arterial pressure before ECMO, a lower level of pCr, and a lower pTB value during ECMO (all P < 0.05). Conclusion: ECMO can effectively promote oxygenation and carbon dioxide (CO2) removal in patients with severe ARDS. Early initiation of ECMO with appropriate management could benefit in reducing comorbidities and mortality. [ABSTRACT FROM AUTHOR]

Backgroud: In recent years, as the number of people with obesity has surged, the number of morbidly obese patients has also grown. The pathophysiological changes in morbid obesity can lead to combined lung diseases, which may result in hypoventilation, hypoxemia, acute upper airway obstruction, acute respiratory distress syndrome, and sleep apnea syndrome, posing serious challenges to anesthesia management. Here, we describe a case of the administration of remimazolam combined with remifentanil in a patient with morbid obesity undergoing gastroscopy. This has rarely been reported in clinical practice, and we present our management experience here with the aim of providing a reference for clinical work. Case presentation: We report the case of a 32-year-old male hypertensive patient with a height of 180 cm, weight of 145 kg, and body mass index of 44.8 kg/m2. The patient's main complaint was intermittent hunger pain for more than 1 year, and duodenal polyps were found. Considering the patient's morbid obesity and the combination of sleep apnea syndrome and hypertension, we administered remimazolam along with remifentanil to ensure perioperative safety. Conclusion: The procedure lasted 30 min, and the anesthesia was satisfactory with no complications. Remimazolam combined with remifentanil intravenous anesthesia is safe for short gastroscopy in patients with morbidly obesity. The administration of a small dose of split-titration delivery facilitates the maintenance of stable vital signs. [ABSTRACT FROM AUTHOR]

The lung is a highly mechanical organ as it is exposed to approximately 109 strain cycles, (where strain is the length change of tissue structure per unit initial length), with an approximately 4% amplitude change during quiet tidal breathing or 107 strain cycles at a 25% amplitude during heavy exercises, sighs, and deep inspirations. These mechanical indices have been reported to become aberrant in lung diseases such as acute respiratory distress syndrome (ARDS), pulmonary hypertension, bronchopulmonary dysplasia (BPD), idiopathic pulmonary fibrosis (IPF), and asthma. Through recent innovations, various in vitro systems/bioreactors used to mimic the lung's mechanical strain have been developed. Among these, the Flexcell tension system which is composed of bioreactors that utilize a variety of programs in vitro to apply static and cyclic strain on different cell-types established as 2D monolayer cultures or cell-embedded 3D hydrogel models, has enabled the assessment of the response of different cells such as fibroblasts to the lung's mechanical strain in health and disease. Fibroblasts are the main effector cells responsible for the production of extracellular matrix (ECM) proteins to repair and maintain tissue homeostasis and are implicated in the excessive deposition of matrix proteins that leads to lung fibrosis. In this review, we summarise, studies that have used the Flexcell tension bioreactor to assess effects of the mechanical lung on the structure, function, and phenotype of lung fibroblasts in homeostatic conditions and abnormal environments associated with lung injury and disease. We show that these studies have revealed that different strain conditions regulate fibroblast proliferation, ECM protein production, and inflammation in normal repair and the diseased lung. [ABSTRACT FROM AUTHOR]

In this review, we aimed to comprehensively summarize current literature on pathophysiology, relevance, diagnosis and treatment of fluid accumulation in patients with sepsis/septic shock. Fluid accumulation syndrome (FAS) is defined as fluid accumulation (any degree, expressed as percentage from baseline body weight) with new onset organ-failure. Over the years, many studies have described the negative impact of FAS on clinically relevant outcomes. While the relationship between FAS and ICU outcomes is well described, uncertainty exists regarding its diagnosis, monitoring and treatment. A stepwise approach is suggested to prevent and treat FAS in patients with septic shock, including minimizing fluid intake (e.g., by limiting intravenous fluid administration and employing de-escalation whenever possible), limiting sodium and chloride administration, and maximizing fluid output (e.g., with diuretics, or renal replacement therapy). Current literature implies the need for a multi-tier, multi-modal approach to de-resuscitation, combining a restrictive fluid management regime with a standardized early active de-resuscitation, maintenance fluid reduction (avoiding fluid creep) and potentially using physical measures such as compression stockings. Trial registration: Not applicable. [ABSTRACT FROM AUTHOR]

Background: The effects of obesity on pulmonary gas and blood distribution in patients with acute respiratory failure remain unknown. Dual-energy computed tomography (DECT) is a X-ray-based method used to study regional distribution of gas and blood within the lung. We hypothesized that 1) regional gas/blood mismatch can be quantified by DECT; 2) obesity influences the global and regional distribution of pulmonary gas and blood; 3) regardless of ventilation modality (invasive vs. non-invasive ventilation), patients' body mass index (BMI) has an impact on pulmonary gas/blood mismatch. Methods: This single-centre prospective observational study enrolled 118 hypoxic COVID-19 patients (92 male) in need of respiratory support and intensive care who underwent DECT. The cohort was divided into three groups according to BMI: 1. BMI<25 kg/m2 (non-obese), 2. BMI = 25-40 kg/m2 (overweight to obese), and 3. BMI>40 kg/m2 (morbidly obese). Gravitational analysis of Hounsfield unit distribution of gas and blood was derived from DECT and used to calculate regional gas/blood mismatch. A sensitivity analysis was performed to investigate the influence of the chosen ventilatory modality and BMI on gas/blood mismatch and adjust for other possible confounders (i.e., age and sex). Results: 1) Regional pulmonary distribution of gas and blood and their mismatch were quantified using DECT imaging. 2) The BMI>40 kg/m2 group had less hyperinflation in the non-dependent regions and more lung collapse in the dependent regions compared to the other BMI groups. In morbidly obese patients, gas and blood were more evenly distributed; therefore, the mismatch was lower than in other patients (30% vs. 36%, p < 0.05). 3) An increase in BMI of 5 kg/m2 was associated with a decrease in mismatch of 3.3% (CI: 3.67% to -2.93%, p < 0.05). Neither the ventilatory modality nor age and sex affected the gas/blood mismatch (p > 0.05). Conclusion: 1) In a hypoxic COVID-19 population needing intensive care, pulmonary gas/blood mismatch can be quantified at a global and regional level using DECT. 2) Obesity influences the global and regional distribution of gas and blood within the lung, and BMI>40 kg/m2 improves pulmonary gas/blood mismatch. 3) This is true regardless of the ventilatory mode and other possible confounders, i.e., age and sex. [ABSTRACT FROM AUTHOR]

Background: Pathogenic diversity may have contributed to the high mortality of pneumonia-associated acute respiratory distress syndrome (p-ARDS). Metagenomics next-generation sequencing (mNGS) serves as a valuable diagnostic tool for early pathogen identification. However, its clinical utility in p-ARDS remains understudied. There are still limited researches on the etiology, clinical characteristics and risk factors for 28-day mortality in p-ARDS patients. Methods: A single center retrospective cohort study of 75 p-ARDS patients was conducted. Patients were categorized into survival and deceased groups based on their 28-day outcomes. A comprehensive clinical evaluation was conducted, including baseline characteristics, laboratory indicators, outcomes and pathogen identification by mNGS and traditional microbiological testing. We then evaluated the diagnostic value of mNGS and identified clinical characteristics and risk factors for 28-day mortality in p-ARDS. Result: The overall ICU mortality was 26.67%, and the 28-day mortality was 57.33%, with 32 cases (42.67%) in the survival group, and 43 cases (57.33%) in the deceased group. Patients in the deceased group were older than those in the survival group (68(59,73) years vs. 59(44,67) years, P=0.04). The average lengths of ICU and hospital stay were 9(5,13) days and 14(7,21) days, respectively. The survival group had longer lengths of ICU and hospital stay (ICU: 11(7,17) days and hospital: 17(9,27) days) compared to the deceased group (ICU: 8(4,11) days and hospital: 12(6,19) days) (P<0.05). Survival patients exhibited lower Acute Physiology and Chronic Health Evaluation (APACHE) II score on the 3rd and 7th days, higher lymphocyte counts, higher CD3+ and CD8+ T cell counts compared to deceased patients (P<0.05). Multivariate logistic regression analysis identified age, APACHE II scores on 3rd and 7th days, CD8+ T cell count and length of ICU as independent risk factors for 28-day mortality in p-ARDS patients. mNGS demonstrated a significantly higher overall pathogen detection rate (70/75, 93.33%) compared to the traditional method (50/75, 66.67%, P=0.022). The average turnaround time (TAT) for mNGS was significantly shorter at 1(1,1) day compared to 4(3,5) days for the traditional method (P<0.001). Conclusion: Metagenome next-generation sequencing can be used as a valuable tool for identifying pathogens in p-ARDS, reducing diagnostic time and improving accuracy. Early application of mNGS alongside traditional methods is recommended for p-ARDS. Furthermore, older age, higher APACHE II scores, lower lymphocyte counts and lymphocyte subset counts were associated with increased mortality in p-ARDS patients, highlighting the importance of timely assessment of immune status and disease severity, especially in elderly. [ABSTRACT FROM AUTHOR]

Background: Iliacus muscle abscess is an uncommon but potentially life-threatening condition that can present with nonspecific symptoms, posing diagnostic challenges. This case report highlights the importance of considering iliopsoas abscess in patients presenting with fever and hip pain, especially in the absence of obvious risk factors or penetrating trauma. The novelty of this case lies in its atypical presentation mimicking a respiratory viral infection and musculoskeletal injury, impeding accurate diagnosis and appropriate management. Case Presentation: A previously healthy 21-year-old female who had a mechanical fall 3 weeks prior presented with fever, right hip pain, and respiratory symptoms, initially suggestive of a respiratory infection and musculoskeletal injury. However, initial investigations revealing a markedly high C-reactive protein (CRP) concentration prompted further computed tomography (CT) imaging of her abdomen and pelvis, which uncovered an iliopsoas abscess presumably stemming from antecedent trauma. Subsequent CT guided aspiration along with culture-sensitive antibiotics led to successful treatment and resolution of her symptoms. Conclusions: This case emphasizes the importance of considering iliopsoas abscess as a possible differential, even in young patients without typical risk factors. Markedly elevated inflammatory markers such as CRP concentrations can serve as a vital indicator, directing attention towards the possibility of septicemia or the presence of an occult abscess, facilitating prompt imaging and accurate diagnosis. [ABSTRACT FROM AUTHOR]

Context: Critically ill patients, especially those with respiratory failure associated with multiple comorbidities, are at risk of recurrent ICU admission and consuming a significant portion of medical resources. Aim: To study the risk factors and common etiologies of readmission among surviving patients with acute respiratory failure in Mansoura University's respiratory intensive care unit during the year 2023. Settings and design: This was a retrospective cohort study. Patients and methods: This study included all patients with acute respiratory failure who were admitted to Mansoura University's respiratory intensive care unit (RICU), from January 2023 to December 2023. Deceased patients after initial admission or those with incomplete data were not included in the study. All data related to patient's demographics, type of respiratory failure, type of respiratory support, associated comorbidities, length of ICU stay, and causes of readmission were collected from the registration system database. Results: Eight-hundred-thirty (830) cases that were admitted to the Mansoura University's RICU with respiratory failure in the year 2023 were enrolled in the study, and 84 cases (10.1%) of them were readmitted. COPD exacerbation was the most common cause of readmission (35.7%) followed by pneumonia (21.4%) and OSA exacerbation (20.2%). Results showed that the significant independent predictors of readmission were being male [AOR (95% CI): 1.8 (1.01–3.1), p: 0.046], having organ failure (renal/liver) [AOR (95% CI): 29.9 (7.9–113.4), p ≤ 0.001], and length of ICU stay more than 12 days [AOR (95% CI): 4.8 (2.6–8.6), p ≤ 0.001]. Also, the type of respiratory failure and the type of respiratory support received were significantly associated with readmission in the univariate analysis; however, they were insignificant in the multivariate analysis. Conclusion: The rate of readmission was not high (only 10.3%). The most common causes of readmission were COPD exacerbation, followed by pneumonia and OSA exacerbation, respectively. Type of respiratory failure, male gender, the presence of other organ failure, and length of ICU stay are significant independent predictors of readmission in Mansoura University's RICU during the year 2023. Therefore, higher-risk individuals should receive attention and careful assessment before discharge from the ICU to reduce the rate of readmission. Trial registration: ClinicalTrials.gov identifier: NCT06291636. [ABSTRACT FROM AUTHOR]