Mortality In Acute Respiratory Distress Syndrome Research Articles

Respiratory support strategies for ARDS related to infection

Sepsis is one of the main causes of acute respiratory distress syndrome (ARDS), which continues to be a common cause of high mortality in intensive care units (ICUs). Despite tremendous advances in basic science and clinical research, the high mortality of ARDS remains a major clinical challenge. Currently, there is a lack of specific and effective therapeutic approaches for ARDS, with treatment primarily focused on supporting organ function. This article provided a comprehensive discussion and summary of respiratory support strategies for sepsis associated with ARDS.

Mitochondrial transplantation attenuates lipopolysaccharide-induced acute respiratory distress syndrome

BackgroundThe mitochondria are essential organelles not only providing cellular energy in the form of ATP, but also regulating the inflammatory response and the cell death program. Mitochondrial dysfunction has been associated with various human diseases, including metabolic syndromes as well as inflammatory and neurodegenerative diseases. Acute respiratory distress syndrome (ARDS) is an acute pulmonary disorder characterized by uncontrolled alveolar inflammation, apoptotic lung epithelial/endothelial cells, and pulmonary edema. Despite the high mortality of ARDS, an effective pharmacotherapy to treat this disease has not been established yet. Therefore, identifying a novel targeted therapy for ARDS is important. Recently, exogenous mitochondrial transplantation was reported to be beneficial for treating mitochondrial dysfunction. The current study aimed to investigate the therapeutic effect of mitochondrial transplantation on ARDS in vitro and in vivo.MethodsMitochondria were isolated from human stem cells. For in vitro efficacy of mitochondrial transplantation on the inflammation and cell death, murine alveolar macrophages MH-S and human pulmonary microvascular endothelial cells HPMECs were exposed to LPS, respectively. The ARDS mice model established by a single intratracheal instillation of LPS was used for in vivo efficacy of intravenously treated mitochondria.ResultsOur results showed that the mitochondria isolated from human stem cells exhibited an anti-inflammatory effect against alveolar macrophages and an anti-apoptotic effect against the alveolar epithelial cells. Furthermore, intravenous mitochondrial treatment was associated with the attenuation of lung injury in the LPS-induced ARDS mice.ConclusionDual effects of mitochondria on anti-inflammation and anti-apoptosis support the potential of mitochondrial transplantation as a novel therapeutic strategy for ARDS.

Increased plasma AACT level as an indicator of poor prognosis in patients hospitalised with community-acquired pneumonia: a multicentre prospective cohort study

Background and objectiveCommunity-acquired pneumonia (CAP) is a common respiratory disease that frequently requires hospitalisation, and is a significant cause of death worldwide. This study aimed to evaluate the usefulness of alpha-1-antichymotrypsin (AACT) as a diagnostic and prognostic biomarker of CAP.MethodsWe conducted a multicentre prospective cohort study in patients hospitalised with CAP. Plasma AACT levels were measured using a quantitative enzyme-linked immunosorbent assay. Receiver-operating characteristic (ROC) curves and Cox proportional hazards regression were used to assess the association between plasma AACT levels and CAP diagnosis and prognosis.ResultsA total of 274 patients with CAP were enrolled in the study. AACT levels were elevated in patients with CAP, especially those with severe CAP and non-survivors. The area under the curve (AUC) of AACT and CRP for diagnosing CAP was 0.755 and 0.843. Cox regression showed that CURB-65 and AACT levels were independent predictors of 30-day mortality. ROC curves showed that plasma AACT levels had the highest accuracy for predicting acute respiratory distress syndrome (ARDS), with an AUC of 0.862. Combining AACT with Pneumonia Severity Index and CURB-65 significantly improved their predictive accuracy for predicting 30-day mortality.ConclusionPlasma AACT levels are elevated in patients with CAP, but plasma AACT level is inferior to the C-reactive protein level for diagnosing CAP. The AACT level can reliably predict the occurrence of ARDS and 30-day mortality in patients with CAP.

Impact of cardiovascular risk factors and cardiac diseases on mortality in patients with moderate to severe ARDS: A retrospective cohort study

BackgroundHistory of coronary artery disease (CAD) and/or atrial fibrillation (AF) and/or valvular replacement (VR) are prevalent among patients admitted to intensive care units (ICUs). The impact of these conditions on outcomes in patients with acute respiratory distress syndrome (ARDS) remains insufficiently explored. MethodsWe performed a retrospective study on prospectively collected data from patients with ARDS and a PaO2/FiO2 ratio ≤150 mmHg. Patients were admitted between January 2006 and March 2022. We used multivariable logistic regression analysis. The primary outcome was 1-year mortality from admission to the ICU; secondary outcomes included mortality at 28 days and 90 days. ResultsAmong 1.033 patients, 181 (17.5 %) had a history of CAD and/or AF and/or VR. History of CAD and/or AF and/or VR was independently associated with 1-year mortality (Odds-Ratio (OR) = 2.59, 95 % confidence interval (CI) 1.76–3.82, p < 0.001), with mortality at 90 days (OR = 1.87, 95 % CI 1.27–2.76, p = 0.001), but not with mortality at 28 days (OR = 1.40, 95 % CI 0.93–2.11, p = 0.10). In sensitivity analyses, history of CAD and/or AF and/or VR remained independently associated with 1-year mortality in ICU survivors (OR = 3.58, 95 % CI = 2.41–7.82, p < 0.001). ConclusionsHistory of CAD and/or AF and/or VR was associated with mortality in ARDS. Prompt referral to cardiologists for comprehensive management post-ICU discharge may be warranted to optimize outcomes in this vulnerable population.

Early predictive values of clinical assessments for ARDS mortality: a machine-learning approach

Acute respiratory distress syndrome (ARDS) is a devastating critical care syndrome with significant morbidity and mortality. The objective of this study was to evaluate the predictive values of dynamic clinical indices by developing machine-learning (ML) models for early and accurate clinical assessment of the disease prognosis of ARDS. We conducted a retrospective observational study by applying dynamic clinical data collected in the ARDSNet FACTT Trial (n = 1000) to ML-based algorithms for predicting mortality. In order to compare the significance of clinical features dynamically, we further applied the random forest (RF) model to nine selected clinical parameters acquired at baseline and day 3 independently. An RF model trained using clinical data collected at day 3 showed improved performance and prognostication efficacy (area under the curve [AUC]: 0.84, 95% CI: 0.78–0.89) compared to baseline with an AUC value of 0.72 (95% CI: 0.65–0.78). Mean airway pressure (MAP), bicarbonate, age, platelet count, albumin, heart rate, and glucose were the most significant clinical indicators associated with mortality at day 3. Thus, clinical features collected early (day 3) improved performance of integrative ML models with better prognostication for mortality. Among these, MAP represented the most important feature for ARDS patients’ early risk stratification.

The Association between Dynamic Pressure Gradient and Mortality in Patients with Acute Respiratory Distress Syndrome in a Pediatric Intensive Care Unit: A Single-Center Retrospective Cohort

Abstract Background: Lung-protective ventilation strategies, one of which is to limit peak inspiratory pressure (PIP), are recommended in the management of acute respiratory distress syndrome (ARDS). The purpose of this study was to determine whether dynamic pressure gradient, defined as the difference between PIP and positive end-expiratory pressure (PEEP), is associated with pediatric ARDS mortality in the pediatric intensive care unit (PICU). Materials and Methods: This was a retrospective, single-center cohort study with consecutive sampling. Children aged 1 month to 18 years with ARDS who were admitted to PICU and used invasive mechanical ventilator between January and December 2023 were included. Patient’s demographic data, pediatric logistic organ dysfunction 2 (PELOD-2) score, oxygenation index (OI), oxygen saturation index (OSI), PEEP, and dynamic pressure gradient were collected from the patient’s medical record. The outcome is mortality, which is measured upon discharge. Results: The subjects’ median age was 6 months, predominantly male (64.06%). The etiology of ARDS was pneumonia (90.63%) and sepsis (9.37%). Bivariate analysis showed that dynamic pressure gradient (OR = 4.77, 95% CI=1.47–15.5, P = 0.003), PEEP (OR = 3.21, 95% CI = 1.07–9.52, P = 0.033), and PELOD-2 score at 24–72 h (OR = 3.68, 95% CI = 1.146–11.83, P = 0.024) had a significant association with mortality of ARDS patients at PICU. The results of multivariate analysis showed that dynamic pressure gradient had a significant relationship with the mortality of ARDS patients at PICU (OR = 5.22, 95% CI = 1.47–18.56, P = 0.015). Conclusion: Dynamic pressure gradient was associated with mortality in pediatric patients with ARDS who were treated in PICU.

The Ventilatory Ratio as a Predictor of Successful Weaning from a Veno-Venous Extracorporeal Membrane Oxygenator.

Background: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a critical intervention for patients with severe lung failure, especially acute respiratory distress syndrome (ARDS). The weaning process from ECMO relies largely on expert opinion due to a lack of evidence-based guidelines. The ventilatory ratio (VR), which correlates with dead space and mortality in ARDS, is calculated as [minute ventilation (mL/min) x arterial pCO2 (mmHg)]/[predicted body weight × 100 × 37.5]. Objectives: The aim of this study was to determine whether the VR alone can serve as a reliable predictor of safe or unsafe liberation from VV-ECMO in critically ill patients. Methods: A multicenter retrospective analysis was conducted, involving ARDS patients undergoing VV-ECMO weaning at Massachusetts General Hospital (January 2016 - December 2020) and at the University Hospital Aachen (January 2012-December 2021). Safe liberation was defined as no need for ECMO recannulation within 48 h after decannulation. Clinical parameters were obtained for both centers at the same time point: 30 min after the start of the SGOT (sweep gas off trial). Results: Of the patients studied, 83.3% (70/84) were successfully weaned from VV-ECMO. The VR emerged as a significant predictor of unsafe liberation (OR per unit increase: 0.38; CI: 0.17-0.81; p = 0.01). Patients who could not be safely liberated had longer ICU and hospital stays, with a trend towards higher mortality (38% vs. 13%; p = 0.05). Conclusions: The VR may be a valuable predictor for safe liberation from VV-ECMO in ARDS patients, with higher VR values associated with an elevated risk of unsuccessful weaning and adverse clinical outcomes.

Comparison of venovenous extracorporeal membrane oxygenation, prone position and supine mechanical ventilation for severely hypoxemic acute respiratory distress syndrome: a network meta-analysis.

Severe acute respiratory distress syndrome (ARDS) with PaO2/FiO2 < 80mmHg is a life-threatening condition. The optimal management strategy is unclear. The aim of this meta-analysis was to compare the effects of low tidal volumes (Vt), moderate Vt, prone ventilation, and venovenous extracorporeal membrane oxygenation (VV-ECMO) on mortality in severe ARDS. We performed a frequentist network meta-analysis of randomised controlled trials (RCTs) with participants who had severe ARDS and met eligibility criteria for VV-ECMO or had PaO2/FiO2 < 80mmHg. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to discern the relative effect of interventions on mortality and the certainty of the evidence. Ten RCTs including 812 participants with severe ARDS were eligible. VV-ECMO reduces mortality compared to low Vt (risk ratio [RR] 0.77, 95% confidence interval [CI] 0.59-0.99, moderate certainty) and compared to moderate Vt (RR 0.75, 95% CI 0.57-0.98, low certainty). Prone ventilation reduces mortality compared to moderate Vt (RR 0.78, 95% CI 0.66-0.93, high certainty) and compared to low Vt (RR 0.81, 95% CI 0.63-1.02, moderate certainty). We found no difference in the network comparison of VV-ECMO compared to prone ventilation (RR 0.95, 95% CI 0.72-1.26), but inferences were based solely on indirect comparisons with very low certainty due to very wide confidence intervals. In adults with ARDS and severe hypoxia, both VV-ECMO (low to moderate certainty evidence) and prone ventilation (moderate to high certainty evidence) improve mortality relative to low and moderate Vt strategies. The impact of VV-ECMO versus prone ventilation remains uncertain.

TM9SF1 offers utility as an efficient predictor of clinical severity and mortality among acute respiratory distress syndrome patients.

Acute respiratory distress syndrome (ARDS) is a major cause of death among critically ill patients in intensive care settings, underscoring the need to identify biomarkers capable of predicting ARDS patient clinical status and prognosis at an early time point. This study specifically sought to explore the utility and clinical relevance of TM9SF1 as a biomarker for the early prediction of disease severity and prognostic outcomes in patients with ARDS. This study enrolled 123 patients with severe ARDS and 116 patients with non-severe ARDS for whom follow-up information was available. The mRNA levels of TM9SF1 and cytokines in peripheral blood mononuclear cells from these patients were evaluated by qPCR. The predictive performance of TM9SF1 and other clinical indicators was evaluated using received operating characteristic (ROC) curves. A predictive nomogram was developed based on TM9SF1 expression and evaluated for its ability in the early prediction of severe disease and mortality in patients with ARDS. TM9SF1 mRNA expression was found to be significantly increased in patients with severe ARDS relative to those with non-severe disease or healthy controls. ARDS severity increased in correspondence with the level of TM9SF1 expression (odds ratio [OR] = 2.43, 95% confidence interval [CI] = 2.15-3.72, P = 0.005), and high TM9SF1 levels were associated with a greater risk of mortality (hazard ratio [HR] = 2.27, 95% CI = 2.20-4.39, P = 0.001). ROC curves demonstrated that relative to other clinical indicators, TM9SF1 offered superior performance in the prediction of ARDS severity and mortality. A novel nomogram incorporating TM9SF1 expression together with age, D-dimer levels, and C-reactive protein (CRP) levels was developed and was used to predict ARDS severity (AUC = 0.887, 95% CI = 0.715-0.943). A separate model incorporating TM9SF1 expression, age, neutrophil-lymphocyte ratio (NLR), and D-dimer levels (C-index = 0.890, 95% CI = 0.627-0.957) was also developed for predicting mortality. Increases in ARDS severity and patient mortality were observed with rising levels of TM9SF1 expression. TM9SF1 may thus offer utility as a novel biomarker for the early prediction of ARDS patient disease status and clinical outcomes.

Causes and attributable fraction of death from ARDS in inflammatory phenotypes of sepsis

BackgroundHypoinflammatory and hyperinflammatory phenotypes have been identified in both Acute Respiratory Distress Syndrome (ARDS) and sepsis. Attributable mortality of ARDS in each phenotype of sepsis is yet to be determined. We aimed to estimate the population attributable fraction of death from ARDS (PAFARDS) in hypoinflammatory and hyperinflammatory sepsis, and to determine the primary cause of death within each phenotype.MethodsWe studied 1737 patients with sepsis from two prospective cohorts. Patients were previously assigned to the hyperinflammatory or hypoinflammatory phenotype using latent class analysis. The PAFARDS in patients with sepsis was estimated separately in the hypo and hyperinflammatory phenotypes. Organ dysfunction, severe comorbidities, and withdrawal of life support were abstracted from the medical record in a subset of patients from the EARLI cohort who died (n = 130/179). Primary cause of death was defined as the organ system that most directly contributed to death or withdrawal of life support.ResultsThe PAFARDS was 19% (95%CI 10,28%) in hypoinflammatory sepsis and, 14% (95%CI 6,20%) in hyperinflammatory sepsis. Cause of death differed between the two phenotypes (p < 0.001). Respiratory failure was the most common cause of death in hypoinflammatory sepsis, whereas circulatory shock was the most common cause in hyperinflammatory sepsis. Death with severe underlying comorbidities was more frequent in hypoinflammatory sepsis (81% vs. 67%, p = 0.004).ConclusionsThe PAFARDS is modest in both phenotypes whereas primary cause of death among patients with sepsis differed substantially by phenotype. This study identifies challenges in powering future clinical trials to detect changes in mortality outcomes among patients with sepsis and ARDS.

Evaluation of the effect of aminophylline on inflammatory parameters in COVID-19 patients with acute respiratory distress syndrome

Background: In Acute respiratory distress syndrome (ARDS), invasion and activation of pro- and anti-inflammatory mediators and cytokines result in oxidative damage to the lung tissue. Aminophylline is a combination of theophylline and ethyl diamine, has anti-inflammatory, bronchodilator, ROS inhibitor effects, and stimulates surfactant release. Mortality of ARDS in COVID-19 patients is high; aminophylline is expected to reduce the incidence of mortality. Information regarding the use of aminophylline in COVID-19 patients with ARDS is still limited. Objective: To evaluate the efficacy of aminophylline in inflammatory parameters in COVID-19 patients with ARDS. Methods: It was a retrospective cohort observational study at the Universitas Airlangga Hospital. Samples were hospitalised COVID-19 patients with ARDS who received a loading dose of 240-480 mg and a maintenance dose of 720-960 mg aminophylline. The primary outcomes were improved C-reactive protein (CRP), IL-6, lymphocytes, neutrophils, and Neutrophil-lymphocyte ratio (NLR), which were measured before and after administration of aminophylline with a duration of therapy of 1-5 days. Result: A total of 50 patients with ARDS were enrolled in the study. Lymphocyte and CRP decreased (p = 0.002; p = 0.128). IL-6, neutrophil, and NLR increased (p = 0.255; p = 0.064; p = 0.005). Conclusion: It can be concluded that the administration of aminophylline has not improved inflammatory parameters.

Heterogeneity of immune cells and their communications unveiled by transcriptome profiling in acute inflammatory lung injury.

Acute Respiratory Distress Syndrome (ARDS) or its earlier stage Acute lung injury (ALI), is a worldwide health concern that jeopardizes human well-being. Currently, the treatment strategies to mitigate the incidence and mortality of ARDS are severely restricted. This limitation can be attributed, at least in part, to the substantial variations in immunity observed in individuals with this syndrome. Bulk and single cell RNA sequencing from ALI mice and single cell RNA sequencing from ARDS patients were analyzed. We utilized the Seurat program package in R and cellmarker 2.0 to cluster and annotate the data. The differential, enrichment, protein interaction, and cell-cell communication analysis were conducted. The mice with ALI caused by pulmonary and extrapulmonary factors demonstrated differential expression including Clec4e, Retnlg, S100a9, Coro1a, and Lars2. We have determined that inflammatory factors have a greater significance in extrapulmonary ALI, while multiple pathways collaborate in the development of pulmonary ALI. Clustering analysis revealed significant heterogeneity in the relative abundance of immune cells in different ALI models. The autocrine action of neutrophils plays a crucial role in pulmonary ALI. Additionally, there was a significant increase in signaling intensity between B cells and M1 macrophages, NKT cells and M1 macrophages in extrapulmonary ALI. The CXCL, CSF3 and MIF, TGFβ signaling pathways play a vital role in pulmonary and extrapulmonary ALI, respectively. Moreover, the analysis of human single-cell revealed DCs signaling to monocytes and neutrophils in COVID-19-associated ARDS is stronger compared to sepsis-related ARDS. In sepsis-related ARDS, CD8+ T and Th cells exhibit more prominent signaling to B-cell nucleated DCs. Meanwhile, both MIF and CXCL signaling pathways are specific to sepsis-related ARDS. This study has identified specific gene signatures and signaling pathways in animal models and human samples that facilitate the interaction between immune cells, which could be targeted therapeutically in ARDS patients of various etiologies.

Mortality Due to Acute Respiratory Distress Syndrome in Latin America.

Mortality due to acute respiratory distress syndrome (ARDS) is a major global health problem. Knowledge of epidemiological data on ARDS is crucial to design management, treatment strategies, and optimize resources. There is ample data regarding mortality of ARDS from high-income countries; in this review, we evaluated mortality due to ARDS in Latin America. We searched in PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Latin American and Caribbean Health Science Literature databases from 1967 to March 2023. We searched prospective or retrospective observational studies and randomized controlled trials conducted in Latin American countries reporting ARDS mortality. Three pairs of independent reviewers checked all studies for eligibility based on their titles and abstracts. We performed meta-analysis of proportions using a random-effects model. We performed sensitivity analyses including studies with low risk of bias and with diagnosis using the Berlin definition. Subgroup analysis comparing different study designs, time of publication (up to 2000 and from 2001 to present), and studies in which the diagnosis of ARDS was made using Pa o2 /F io2 less than or equal to 200 and regional variations. Subsequently, we performed meta-regression analyses. Finally, we graded the certainty of the evidence (Grading of Recommendations Assessment, Development, and Evaluation). Of 3315 articles identified, 32 were included (3627 patients). Mortality was 52% in the pooled group (low certainty of evidence). In the sensitivity analysis (according to the Berlin definition), mortality was 46% (moderate certainty of evidence). In the subgroup analysis mortality was 53% (randomized controlled trials), 51% (observational studies), 66% (studies published up to 2000), 50% (studies after 2000), 44% (studies with Pa o2 /F io2 ≤ 200), 56% (studies from Argentina/Brazil), and 40% (others countries). No variables were associated with mortality in the meta-regression. ARDS mortality in Latin America remains high, as in other regions. These results should constitute the basis for action planning to improve the prognosis of patients with ARDS (PROSPERO [CRD42022354035]).

Influence of simultaneous comorbidities on COVID-associated acute respiratory distress syndrome mortality in people with diabetes

ObjectivesThis study analyzed the influence of 23 comorbidities on COVID-associated acute distress respiratory syndrome (CARDS) mortality in people with a history of diabetes mellitus. MethodsAn observational, analytical, cross sectional study was utilized to investigate data from 6723 health services in Brazil, comprising 5433 people with diabetes. Adjusted logistic regression models for demographic factors such as age, sex, and race were used to analyze the association between CARDS mortality and comorbidities. ResultsPersons with two (p < 0.001), three (p < 0.001), four (p < 0.001), and five (p < 0.001) simultaneous comorbidities had a higher chance of dying. We identified that diabetes patients who had concomitant metabolic diseases (p = 0.019), neurological disorders (p < 0.001), or were smokers (p < 0.001) had a higher predicted mortality risk based on CADRS. ConclusionThe number of comorbidities plays a determining role in CARDS mortality in people with diabetes, especially those who suffer from smoking and neurological diseases simultaneously.

Blood group O is associated with ARDS development but exhibits lower mortality in the intensive care unit – A retrospective multicentre study

ABSTRACT Background Acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in the intensive care unit (ICU). Previous studies have suggested that blood group A increases the risk of developing ARDS following sepsis and major trauma. This study investigated the association between ABO and Rh blood groups and ARDS development and mortality in ARDS. Methods Patients admitted to the ICUs at Skåne University Hospital in Lund and Malmö, Sweden, in 2016 were retrospectively screened for ARDS according to the Berlin definition. Clinical data, patient characteristics, lab results, and survival data were collected from medical records and registry data. In addition, chest radiographs were reviewed by radiologists. ARDS development and 30-day mortality were analysed using multivariable logistic regression. Results A total of 1439 ICU patients were included. Of these, 10% had ARDS. Blood group O was associated with an increased risk of having or developing ARDS compared to blood group A (odds ratio [OR] 1.79, 95% confidence interval [CI] 1.13–2.84, p = 0.014). Among ARDS patients, blood group O had decreased 30-day mortality compared to blood group A (OR 0.25, 95% CI 0.09–0.67, p = 0.007). The Rh blood group was not associated with ARDS development or mortality. Conclusion In this study of ICU patients, blood group O was associated with an increased risk of having or developing ARDS but a decreased mortality in ARDS compared to blood group A. Further studies are needed to clarify the relationship and underlying mechanisms of the ABO blood group and ARDS.

Post-operative sepsis-induced acute respiratory distress syndrome: risk factors for a life-threatening complication.

Prevalence and mortality of the acute respiratory distress syndrome (ARDS) in intensive care units (ICU) are unacceptably high. There is scarce literature on post-operative sepsis-induced ARDS despite that sepsis and major surgery are conditions associated with ARDS. We aimed to examine the impact of post-operative sepsis-induced ARDS on 60-day mortality. We performed a secondary analysis of a prospective observational study in 454 patients who underwent major surgery admitted into a single ICU. Patients were stratified in two groups depending on whether they met criteria for ARDS. Primary outcome was 60-day mortality of post-operative sepsis-induced ARDS. Secondary outcome measures were potential risk factors for post-operative sepsis-induced ARDS, and for 60-day mortality. Higher SOFA score (OR 1.1, 95% CI 1.0-1.3, p = 0.020) and higher lactate (OR 1.9, 95% CI 1.2-2.7, p = 0.004) at study inclusion were independently associated with ARDS. ARDS patients (n = 45) had higher ICU stay [14 (18) vs. 5 (11) days, p < 0.001] and longer need for mechanical ventilation [6 (14) vs. 1 (5) days, p < 0.001] than non-ARDS patients (n = 409). Sixty-day mortality was higher in ARDS patients (OR 2.7, 95% CI 1.1-6.3, p = 0.024). Chronic renal failure (OR 4.0, 95% CI 1.2-13.7, p = 0.026), elevated lactate dehydrogenase (OR 1.7, 95% CI 1.1-2.7, p = 0.015) and higher APACHE II score (OR 2.7, 95% CI 1.3-5.4, p = 0.006) were independently associated with 60-day mortality. Post-operative sepsis-induced ARDS is associated with higher 60-day mortality compared to non-ARDS post-operative septic patients. Post-operative septic patients with higher severity of illness have a greater risk of ARDS and worse outcomes. Further investigation is needed in post-operative sepsis-induced ARDS to prevent ARDS.

Attributable mortality of ARDS among critically ill patients with sepsis: a multicenter, retrospective cohort study

BackgroundBoth sepsis and acute respiratory distress syndrome (ARDS) are common severe diseases in the intensive care unit (ICU). There is no large-scale multicenter study to clarify the attributable mortality of ARDS among septic patients. This study aimed to evaluate the excess mortality of ARDS in critically ill patients with sepsis.MethodsThe data were obtained from a multicenter, prospective cohort study in 18 Chinese ICUs between January 2014 and August 2015. The study population was septic patients after ICU admission. The patients were categorized into two groups: those who developed ARDS (ARDS group) within seven days following a sepsis diagnosis and those who did not develop ARDS (non-ARDS group). Applying propensity score matching (PSM), patients were matched 1:1 as ARDS and non-ARDS groups. Mortality attributed to ARDS was calculated. Subsequently, we conducted a survival analysis to estimate the impact of ARDS on mortality. The primary endpoint was 30-day mortality after sepsis diagnosis.Results2323 septic patients were eligible, 67.8% developed ARDS. After PSM, 737 patients with ARDS were matched 1:1 with 737 non-ARDS patients. ARDS’s overall 30-day attributable mortality was 11.9% (95% CI 7.5–16.3%, p < 0.001). Subgroup analysis showed that the 30-day attributable mortality of mild, moderate, and severe ARDS was 10.5% (95% CI 4.0-16.8%, p < 0.001), 11.6% (95% CI 4.7–18.4%, p < 0.001) and 18.1% (95% CI 4.5–30.9%, p = 0.006), respectively. ARDS was an independent risk factor for 30-day mortality, with adjusted hazard ratios of 1.30 (95% CI 1.03–1.64, p = 0.027), 1.49 (95% CI 1.20–1.85, p < 0.001), and 1.95 (95% CI 1.51–2.52, p < 0.001) for mild, moderate, and severe ARDS, respectively.ConclusionsThe overall 30-day attributable mortality of ARDS among critically ill patients with sepsis was 11.9%. Compared with mild and moderate ARDS, severe ARDS contributed more to death. ARDS was significantly associated with an increase in the 30-day mortality.

Gut microbiota and its metabolic products in acute respiratory distress syndrome.

The prevalence rate of acute respiratory distress syndrome (ARDS) is estimated at approximately 10% in critically ill patients worldwide, with the mortality rate ranging from 17% to 39%. Currently, ARDS mortality is usually higher in patients with COVID-19, giving another challenge for ARDS treatment. However, the treatment efficacy for ARDS is far from satisfactory. The relationship between the gut microbiota and ARDS has been substantiated by relevant scientific studies. ARDS not only changes the distribution of gut microbiota, but also influences intestinal mucosal barrier through the alteration of gut microbiota. The modulation of gut microbiota can impact the onset and progression of ARDS by triggering dysfunctions in inflammatory response and immune cells, oxidative stress, cell apoptosis, autophagy, pyroptosis, and ferroptosis mechanisms. Meanwhile, ARDS may also influence the distribution of metabolic products of gut microbiota. In this review, we focus on the impact of ARDS on gut microbiota and how the alteration of gut microbiota further influences the immune function, cellular functions and related signaling pathways during ARDS. The roles of gut microbiota-derived metabolites in the development and occurrence of ARDS are also discussed.

A Razor's Edge: Vascular Responses to Acute Inflammatory Lung Injury/Acute Respiratory Distress Syndrome.

Historically considered a metabolically inert cellular layer separating the blood from the underlying tissue, the endothelium is now recognized as a highly dynamic, metabolically active tissue that is critical to organ homeostasis. Under homeostatic conditions, lung endothelial cells (ECs) in healthy subjects are quiescent, promoting vasodilation, platelet disaggregation, and anti-inflammatory mechanisms. In contrast, lung ECs are essential contributors to the pathobiology of acute respiratory distress syndrome (ARDS), as the quiescent endothelium is rapidly and radically altered upon exposure to environmental stressors, infectious pathogens, or endogenous danger signals into an effective and formidable regulator of innate and adaptive immunity. These dramatic perturbations, produced in a tsunami of inflammatory cascade activation, result in paracellular gap formation between lung ECs, sustained lung edema, and multi-organ dysfunction that drives ARDS mortality. The astonishing plasticity of the lung endothelium in negotiating this inflammatory environment and efforts to therapeutically target the aberrant ARDS endothelium are examined in further detail in this review.

Association between Age and Mortality in Pediatric and Adult Acute Respiratory Distress Syndrome.

Rationale: The epidemiology, management, and outcomes of acute respiratory distress syndrome (ARDS) differ between children and adults, with lower mortality rates in children despite comparable severity of hypoxemia. However, the relationship between age and mortality is unclear.Objective: We aimed to define the association between age and mortality in ARDS, hypothesizing that it would be nonlinear.Methods: We performed a retrospective cohort study using data from two pediatric ARDS observational cohorts (n = 1,236), multiple adult ARDS trials (n = 5,547), and an adult observational ARDS cohort (n = 1,079). We aligned all datasets to meet Berlin criteria. We performed unadjusted and adjusted logistic regression using fractional polynomials to assess the potentially nonlinear relationship between age and 90-day mortality, adjusting for sex, PaO2/FiO2, immunosuppressed status, year of study, and observational versus randomized controlled trial, treating each individual study as a fixed effect.Measurements and Main Results: There were 7,862 subjects with median ages of 4 years in the pediatric cohorts, 52 years in the adult trials, and 61 years in the adult observational cohort. Most subjects (43%) had moderate ARDS by Berlin criteria. Ninety-day mortality was 19% in the pediatric cohorts, 33% in the adult trials, and 67% in the adult observational cohort. We found a nonlinear relationship between age and mortality, with mortality risk increasing at an accelerating rate between 11 and 65 years of age, after which mortality risk increased more slowly.Conclusions: There was a nonlinear relationship between age and mortality in pediatric and adult ARDS.