Recent advances in understanding acute respiratory distress syndrome

Association Between Albumin Levels and Neonatal Acute Respiratory Distress Syndrome in Newborn Pneumoniae

Objective

This study aims to investigate the relationship between serum albumin levels and neonatal acute respiratory distress syndrome (NARDS) in patients with newborn pneumonia, providing new insights for clinical interventions targeting NARDS.

Methods

A retrospective analysis of medical records of neonatal pneumonia patients admitted to the neonatal intensive care unit (NICU) at a tertiary medical institution from January 2021 to December 2023 was conducted. Patients were stratified based on hypoalbuminemia (defined as serum albumin levels < 35 g/L), clinical thresholds, and albumin level quartiles. To eliminate the impact of potential confounding factors on the results, multivariable logistic regression and propensity score matching (PSM) analyses were performed to calculate the adjusted odds ratio (OR) and 95% confidence interval (95% CI) for the occurrence of NARDS in these patients. Additionally, subgroup analyses were conducted to explore interaction effects.

Results

In this retrospective cohort study, a total of 342 patients with neonatal pneumonia admitted to the NICU were included. The multivariable logistic regression analysis revealed that the incidence of NARDS in patients with hypoalbuminemia was significantly higher than in those with normal albumin levels (OR = 2.16, 95% CI 1.47-4.06, p = 0.017). Compared to patients in quartile Q1 (≥39 g/L), those in quartile Q4 (≤33 g/L) exhibited a significantly increased risk of NARDS (OR = 4.40, 95% CI 1.53-12.63, p = 0.006). After conducting PSM, these associations remained significant. Furthermore, treating serum albumin levels as a continuous variable revealed that each 1 g/L increase was associated with a 17% reduction in NARDS risk (95% CI, 1.08-1.15).

Conclusion

Low serum albumin levels in patients with neonatal pneumonia are closely associated with NARDS, indicating a significant dose-response relationship between the two.

Recent advances in the potential effects of natural products from traditional Chinese medicine against respiratory diseases targeting ferroptosis

Respiratory diseases, marked by structural changes in the airways and lung tissues, can lead to reduced respiratory function and, in severe cases, respiratory failure. The side effects of current treatments, such as hormone therapy, drugs, and radiotherapy, highlight the need for new therapeutic strategies. Traditional Chinese Medicine (TCM) offers a promising alternative, leveraging its ability to target multiple pathways and mechanisms. Active compounds from Chinese herbs and other natural sources exhibit anti-inflammatory, antioxidant, antitumor, and immunomodulatory effects, making them valuable in preventing and treating respiratory conditions. Ferroptosis, a unique form of programmed cell death (PCD) distinct from apoptosis, necrosis, and others, has emerged as a key area of interest. However, comprehensive reviews on how natural products influence ferroptosis in respiratory diseases are lacking. This review will explore the therapeutic potential and mechanisms of natural products from TCM in modulating ferroptosis for respiratory diseases like acute lung injury (ALI), asthma, pulmonary fibrosis (PF), chronic obstructive pulmonary disease (COPD), lung ischemia-reperfusion injury (LIRI), pulmonary hypertension (PH), and lung cancer, aiming to provide new insights for research and clinical application in TCM for respiratory health.

[Sivelestat sodium for treatment of patients with COVID-19-associated acute respiratory distress syndrome in intensive care unit: a single-center retrospective cohort study]

OBJECTIVE

To investigate the effect of sivelestat sodium on survival, oxygenation index, and serum markers for infection in critically ill patients with COVID-19-associated acute respiratory distress syndrome (ARDS).

METHODS

This retrospectively study was performed among the critically ill patients with COVID-19-associated ARDS admitted in the intensive care unit (ICU) at Nanfang Hospital, Southern Medical University. We collected the clinical data of the patients on the first day of ICU admission and on the day of discharge and laboratory tests results of interleukin-6 (IL-6), C-reactive protein (CRP) and procalcitonin (PCT) and oxygenation index on days 1, 3 and 7 following ICU admission. Propensity-score matching was used to match the patients receiving sivelestat sodium to those without the treatment. Cox proportional hazards model and linear regression analysis were used to assess the association of sivelestat sodium treatment with in-hospital mortality and the length of hospital stay.

RESULTS

A total of 199 patients with COVID-19-associated ARDS patients were included for data analysis. After propensity-score matching PSM, 35 patients receiving sivelestat sodium were matched to 70 patients without the treatment. Treatment with of sivelestat sodium was not associated with the reduction of in- hospital mortality (P=0.36), prolonged ICU stay (P=0.39), hospital stay (P=0.68) or improved oxygenation index (P>0.05) of the patients. No significant difference was found in serum CRP or PCT levels between the patients with and without sivelestat sodium treatment, but a significant reduction in IL-6 level was found in sivelestat sodium group (P=0.016).

CONCLUSION

Sivelestat sodium treatment is not correlated with the reduction of mortality or length of hospital stay, but is associated with reduced serum IL-6 level in patients with COVID-19-associated ARDS.

Risk Factors and Clinical Characteristics of Neonatal Acute Respiratory Distress Syndrome Caused by Early Onset Sepsis

PURPOSE

To identify risk factors associated with the development of acute respiratory distress syndrome (ARDS) in infants with early onset sepsis (EOS) and to describe the clinical features.

METHODS

A retrospective study was conducted at the Children's Hospital of Chongqing Medical University between January 2000 and October 2020. The infants were divided into ARDS and non-ARDS groups. Clinical characteristics and risk factors were compared between the two groups.

RESULTS

Two hundred fifty infants (58 with ARDS) were included. Smaller gestational age, lower birth weight (LBW), lower serum albumin level, a higher rate of preterm birth, premature rupture of membranes, antenatal steroid exposure, and lower Apgar score were associated with an increased development of ARDS by univariate analysis (P < 0.05). LBW (β = -0.001, P = 0.000, OR: 0.999, 95% CI: 0.998-0.999) and low serum albumin levels (β = -0.063, P = 0.022, OR: 0.939, 95% CI: 0.889-0.991) were identified as independent risk factors for the development of ARDS by logistic regression analysis. A higher frequency of complications, including persistent pulmonary hypertension, intraventricular hemorrhage, pulmonary hemorrhage, septic shock, and bronchopulmonary dysplasia, was found in the ARDS group (P < 0.05). The rate of mortality was higher for those in the ARDS group than for those in the non-ARDS group (46.6% vs. 15.6%, χ² = 24.205, P = 0.000).

CONCLUSION

Acute respiratory distress syndrome (ARDS) in EOS could lead to a higher frequency of complications and mortality. The risk factors for the development of ARDS were LBW and low serum albumin levels.

Silent information regulator type-1 mediates amelioration of inflammatory response and oxidative stress in lipopolysaccharide-induced acute respiratory distress syndrome

Silent information regulator type-1 (SIRT1) is crucial during the development of acute respiratory distress syndrome (ARDS). We aimed to explore whether SIRT1 activation could protect against ARDS. SIRT1 was activated by its agonist SRT1720. ARDS was induced by intraperitoneal injection of 5 mg/kg lipopolysaccharide (LPS). Lung injuries were determined by the lung wet/dry ratio, inflammatory cells in the broncho-alveolar lavage fluid (BALF) and histological analysis. Inflammatory cytokine release was detected by enzyme-linked immunosorbent assay. The accumulation of neutrophils was detected by myeloperoxidase activity. Oxidative stress was evaluated by malondialdehyde, reduced glutathione, superoxide dismutase and catalase activities. The protein expression levels were detected using western blot. SIRT1 activation, either by SRT1720 administration or recombinant SIRT1, expression eliminated high-dose LPS-induced mortality in mice, attenuated lung injury, influenced cytokine release in BALF and decreased oxidative stress in the lung tissues of ARDS mice. Mechanically, SRT1720 administration inhibited p65 phosphorylation in the lung tissues of ARDS mice. SIRT1 ameliorates inflammatory response and oxidative stress in LPS-induced ARDS.

The Role of Ferroptosis in Acute Respiratory Distress Syndrome

Ferroptosis is a newly discovered type of regulated cell death that is different from apoptosis, necrosis and autophagy. Ferroptosis is characterized by iron-dependent lipid peroxidation, which induces cell death. Iron, lipid and amino acid metabolism is associated with ferroptosis. Ferroptosis is involved in the pathological development of various diseases, such as neurological diseases and cancer. Recent studies have shown that ferroptosis is also closely related to acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS), suggesting that it can be a novel therapeutic target. This article mainly introduces the metabolic mechanism related to ferroptosis and discusses its role in ALI/ARDS to provide new ideas for the treatment of these diseases.

Impact of rs174537 on Critically Ill Patients with Acute Lung Injury: A Secondary Analysis of the OMEGA Randomized Clinical Trial

BACKGROUND

Nutrition in the intensive care unit is vital for patient care; however, immunomodulatory diets rich in PUFAs like γ-linolenic acid (GLA), EPA, and DHA remain controversial for patients with acute respiratory distress syndrome. We postulate that genetic variants impacting PUFA metabolism contribute to mixed responses to PUFA-rich diets.

OBJECTIVES

In this study, we aimed to test the effects of single nucleotide polymorphism (SNP) rs174537 on differential responses to PUFA-rich diets.

METHODS

We performed a secondary analysis of the OMEGA trial (NCT00609180) where 129 subjects received placebo control diets and 143 received omega-oil. DNA was extracted from buffy coats and used to genotype rs174537; plasma was used to quantitate PUFAs. We tested for SNP-diet interactions on PUFA concentrations, inflammatory biomarkers, and patient outcomes.

RESULTS

We observed that all individuals receiving omega-oil displayed significantly higher concentrations of GLA, EPA, and DHA (all P < 0.0001), but they did not vary by genotype at rs174537. Statistically significant SNP-diet interactions were observed on circulating DHA concentrations in African Americans. Specifically, African American T-allele carriers on placebo illustrated elevated DHA concentrations. Additionally, all individuals receiving omega-oil had higher concentrations of EPA-derived urinary F3-isoprostane (Caucasians: P = 0.0011; African Americans: P = 0.0002). Despite these findings, we did not detect any significant SNP-diet interactions on pulmonary functional metrics, clinical outcomes, and mortality.

CONCLUSIONS

This study highlights the importance of genetic and racial contributions to PUFA metabolism and inflammation. In particular, rs174537 had a significant impact on circulating DHA and urinary isoprostane concentrations. Given our relatively small sample size, further investigations in larger multiethnic cohorts are needed to evaluate the impact of rs174537 on fatty acid metabolism and downstream inflammation.

Alleviation of Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome in Rats by Yiqi Huayu Jiedu Decoction: A Tandem Mass Tag-Based Proteomics Study

Background

To study the effect of Yiqi Huayu Jiedu Decoction (YQHYJD) on protein expression in the lung tissue of acute respiratory distress syndrome (ARDS) rats and to explore the underlying molecular therapeutic mechanism of YQHYJD.

Methods

Sprague Dawley rats were administered with YQHYJD by oral gavage for 1 week. The rats were injected with lipopolysaccharide (LPS) to induce ARDS. The lung injury was assessed pathologically. Differentially expressed proteins (DEPs) were screened by quantitative proteomics and analyzed using bioinformatic tools, such as Metascape and Kyoto Encyclopedia of Genes and Genomes (KEGG) mapper. DEPs were verified by parallel reaction monitoring (PRM).

Results

YQHYJD alleviated the LPS-induced pathological damage of lung tissue in rats. There were 134 DEPs among the YQHYJD treatment and model groups. The Genomes pathway analyses revealed that the DEPs were closely related to immune system pathway. The mass spectrometry analysis revealed that YQHYJD exhibits a protective effect on lung tissue by significantly upregulating hematopoietic cell kinase (Hck), phospholipid phosphatase 3 (Plpp3), myristoylated-alanine rich C-kinase substrate (Marcks), and Actin-related protein 2/3 complex subunit 2 (Arpc2), which are related to Fc gamma receptor-mediated phagocytosis pathway.

Conclusion

YQHYJD can alleviate the lung injury of ARDS rats by regulating the Fc gamma receptor-mediated phagocytosis pathway, which is related to immune system.

Can Serum Fibrinogen Predict ARDS?

Acute respiratory distress syndrome (ARDS) has a worldwide mortality of 10% to 30% with severe pneumonia being the primary cause. Diagnosis relies on clinical criteria which may lead to under-recognition and delayed evidence-based interventions. In previous studies, plasma fibrinogen was associated with progression to ARDS among patients with severe pneumonia. This is a prospective cohort study wherein we hypothesized that levels of plasma fibrinogen and change in levels of fibrinogen can predict development of ARDS among a cohort of patients with severe pneumonia based on the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS) consensus criteria. After acquiring consent, plasma fibrinogen levels were extracted upon enrollment and after 48 hours. These extraction times were arbitrarily chosen to determine whether levels rise or decline in relation to the course of disease. A total of 47 patients were prospectively followed within 7 days of enrollment, then divided into 2 groups, which included those who developed ARDS (n = 12, 25%) and those who did not (n = 35, 75%). Fibrinogen levels at baseline had sensitivity and specificity of 41.7% and 57.1%, respectively (P = .932) with an area under the curve (AUC) of 0.492; levels after 48 hours had sensitivity and specificity of 55.6% and 65.6%, respectively (P = .729) with an AUC of 0.538; and delta fibrinogen levels had sensitivity and specificity of 55.6% and 62.5%, respectively (P = 0.581) with an AUC of 0.561. Based on this study, plasma fibrinogen is an unreliable biomarker for predicting ARDS development in patients with severe pneumonia. In setting up this study, we experienced limitations which we had to accept but realizations of these led to the discovery of potential research areas. To our knowledge, this is the first Philippine study attempting to discover a biomarker for ARDS progression. It is recommended that further investigation on local incidence and other biomarkers for ARDS should be done.

Efficacy of glutathione therapy in relieving dyspnea associated with COVID-19 pneumonia: A report of 2 cases

PURPOSE

Infection with COVID-19 potentially can result in severe outcomes and death from "cytokine storm syndrome", resulting in novel coronavirus pneumonia (NCP) with severe dyspnea, acute respiratory distress syndrome (ARDS), fulminant myocarditis and multiorgan dysfunction with or without disseminated intravascular coagulation. No published treatment to date has been shown to adequately control the inflammation and respiratory symptoms associated with COVID-19, apart from oxygen therapy and assisted ventilation. We evaluated the effects of using high dose oral and/or IV glutathione in the treatment of 2 patients with dyspnea secondary to COVID-19 pneumonia.

METHODS

Two patients living in New York City (NYC) with a history of Lyme and tick-borne co-infections experienced a cough and dyspnea and demonstrated radiological findings consistent with novel coronavirus pneumonia (NCP). A trial of 2 g of PO or IV glutathione was used in both patients and improved their dyspnea within 1 h of use. Repeated use of both 2000 mg of PO and IV glutathione was effective in further relieving respiratory symptoms.

CONCLUSION

Oral and IV glutathione, glutathione precursors (N-acetyl-cysteine) and alpha lipoic acid may represent a novel treatment approach for blocking NF-κB and addressing "cytokine storm syndrome" and respiratory distress in patients with COVID-19 pneumonia.

Differences in clinical characteristics of early- and late-onset neonatal sepsis caused by Klebsiella pneumoniae

To identify differences in the clinical characteristics of early- and late-onset sepsis (EOS and LOS) caused by Klebsiella pneumoniae (K. pneumoniae) and to describe the risk factors for multidrug-resistant K. pneumoniae (MDR-KP) infection. Infants with K. pneumoniae-induced sepsis who were admitted to a children's Hospital between Jan 2000 and Dec 2019 were included. All infants were divided into EOS and LOS groups, as well as MDR-KP and non-MDR-KP groups. Demographics, clinical characteristics, and risk factors were compared between the two groups. One hundred eighty infants (66 with EOS and 114 with LOS) were further analyzed, accounting for 36.8% of sepsis cases caused by MDR-KP. The frequency of respiratory failure, bronchopulmonary dysplasia, and intraventricular hemorrhage were more common in the LOS group and a higher rate of acute respiratory distress syndrome was more common in infants in the EOS group (P < 0.05). K. pneumoniae showed a low sensitivity to penicillin, beta-lactams and cephalosporins, and it showed a high sensitivity to levofloxacin, ciprofloxacin, and amikacin. Prematurity, low birth weight, longer antibiotic exposure time, long duration of peripheral catheter insertion, long mechanical ventilation time, and long parenteral nutrition time were associated with an increased rate of MDR-KP infection by univariate analysis (P < 0.05). The regression analysis identified a long antibiotic exposure time (OR = 1.37, 95% CI: 1.01-1.89) and long parenteral nutrition time (OR = 1.39, 95% CI: 1.01-1.89) as independent risk factors for a MDR-KP infection, and a greater gestational age and birth weight were associated with a lower risk of MDR-KP infection (OR = 0.57, 95% CI: 0.40-0.79). LOS caused by K. pneumoniae may lead to a higher frequency of complications. The risk factors for MDR-KP infection were longer duration of antibiotic exposure and parenteral nutrition. A greater gestational age and larger birth weight may decrease the risk of MDR-KP infection.

Integrating molecular pathogenesis and clinical translation in sepsis-induced acute respiratory distress syndrome

Sepsis-induced acute respiratory distress syndrome (ARDS) has high morbidity and mortality and arises after lung infection or infection at extrapulmonary sites. An aberrant host response to infection leads to disruption of the pulmonary alveolar-capillary barrier, resulting in lung injury characterized by hypoxemia, inflammation, and noncardiogenic pulmonary edema. Despite increased understanding of the molecular biology underlying sepsis-induced ARDS, there are no targeted pharmacologic therapies for this devastating condition. Here, we review the molecular underpinnings of sepsis-induced ARDS with a focus on relevant clinical and translational studies that point toward novel therapeutic strategies.

Biomarkers for Acute Respiratory Distress syndrome and prospects for personalised medicine

Acute lung injury (ALI) affects over 10% of patients hospitalised in critical care, with acute respiratory distress syndrome (ARDS) being the most severe form of ALI and having a mortality rate in the region of 40%. There has been slow but incremental progress in identification of biomarkers that contribute to the pathophysiology of ARDS, have utility in diagnosis and monitoring, and that are potential therapeutic targets (Calfee CS, Delucchi K, Parsons PE, Thompson BT, Ware LB, Matthay MA, Thompson T, Ware LB, Matthay MA, Lancet Respir Med 2014, 2:611–-620). However, a major issue is that ARDS is such a heterogeneous, multi-factorial, end-stage condition that the strategies for “lumping and splitting” are critical (Prescott HC, Calfee CS, Thompson BT, Angus DC, Liu VX, Am J Respir Crit Care Med 2016, 194:147–-155). Nevertheless, sequencing of the human genome, the availability of improved methods for analysis of transcription to mRNA (gene expression), and development of sensitive immunoassays has allowed the application of network biology to ARDS, with these biomarkers offering potential for personalised or precision medicine (Sweeney TE, Khatri P, Toward precision medicine Crit Care Med; 2017 45:934-939).

Biomarker panels have potential applications in molecular phenotyping for identifying patients at risk of developing ARDS, diagnosis of ARDS, risk stratification and monitoring. Two subphenotypes of ARDS have been identified on the basis of blood biomarkers: hypo-inflammatory and hyper-inflammatory. The hyper-inflammatory subphenotype is associated with shock, metabolic acidosis and worst clinical outcomes. Biomarkers of particular interest have included interleukins (IL-6 and IL-8), interferon gamma (IFN-γ), surfactant proteins (SPD and SPB), von Willebrand factor antigen, angiopoietin 1/2 and plasminogen activator inhibitor-1 (PAI-1). In terms of gene expression (mRNA) in blood there have been found to be increases in neutrophil-related genes in sepsis-induced and influenza-induced ARDS, but whole blood expression does not give a robust diagnostic test for ARDS.

Despite improvements in management of ARDS on the critical care unit, this complex disease continues to be a major life-threatening event. Clinical trials of β₂-agonists, statins, surfactants and keratinocyte growth factor (KGF) have been disappointing. In addition, monoclonal antibodies (anti-TNF) and TNFR fusion protein have also been unconvincing. However, there have been major advances in methods of mechanical ventilation, a neuromuscular blocker (cisatracurium besilate) has shown some benefit, and stem cell therapy is being developed. In the future, by understanding the role of biomarkers in the pathophysiology of ARDS and lung injury, it is hoped that this will provide rational therapeutic targets and ultimately improve clinical care (Seymour CW, Gomez H, Chang CH, Clermont G, Kellum JA, Kennedy J, Yende S, Angus DC, Crit Care 2017, 21:257).

[A review on neonatal acute respiratory distress syndrome]

Acute respiratory distress syndrome (ARDS) is a common clinical critical disease and is one of the main causes of death and disability in neonates. The etiology and pathogenesis of neonatal ARDS are complicated. It is an acute pulmonary inflammatory disease caused by the lack of pulmonary surfactant (PS) related to various pathological factors. It is difficult to distinguish neonatal ARDS from other diseases. At present, there is no specific treatment method for this disease. Respiratory support, PS replacement, extracorporeal membrane oxygenation, nutrition support and liquid management are main treatment strategies. This paper reviews the research advance in etiology, clinical characteristics, diagnosis and treatment strategies of neonatal ARDS.