The acute respiratory distress syndrome

Tranexamic Acid and Pulmonary Complications: A Secondary Analysis of an EAST Multicenter Trial

BACKGROUND

Anti-inflammatory effects of tranexamic acid (TXA) in reducing trauma endotheliopathy may protect from acute lung injury. Clinical data showing this benefit in trauma patients is lacking. We hypothesized that TXA administration mitigates pulmonary complications in penetrating trauma patients.

MATERIALS AND METHODS

This is a post-hoc analysis of a multicenter, prospective, observational study of adults (18+ years) with penetrating torso and/or proximal extremity injury presenting at 25 urban trauma centers. Tranexamic acid administration in the prehospital setting or within three hours of admission was examined. Participants were propensity matched to compare similarly injured patients. The primary outcome was development of pulmonary complication (ARDS and/or pneumonia).

RESULTS

A total of 2382 patients were included, and 206 (8.6%) received TXA. Of the 206, 93 (45%) received TXA prehospital and 113 (55%) received it within three hours of hospital admission. Age, sex, and incidence of massive transfusion did not differ. The TXA group was more severely injured, more frequently presented in shock (SBP < 90 mmHg), developed more pulmonary complications, and had lower survival (P < 0.01 for all). After propensity matching, 410 patients remained (205 in each cohort) with no difference in age, sex, or rate of shock. On logistic regression, increased emergency department heart rate was associated with pulmonary complications. Tranexamic acid was not associated with different rate of pulmonary complications or survival on logistic regression. Survival was not different between the groups on logistic regression or propensity score-matched analysis.

CONCLUSIONS

Tranexamic acid administration is not protective against pulmonary complications in penetrating trauma patients.

Segmental Shielding: A Rare Case of Acute Respiratory Distress Syndrome with Middle Lobe Sparing

Acute respiratory distress syndrome (ARDS) presents a formidable challenge in critical care, often resulting in high mortality rates, particularly in severe cases or those compounded by preexisting conditions. Despite substantial advancements in critical care, the heterogeneous nature of ARDS necessitates nuanced clinical approaches. ARDS is generally diagnosed through clinical evaluation, radiographic imaging, and laboratory tests, as well as acute onset, bilateral lung infiltrates on imaging, and a partial pressure of oxygen in arterial blood (PaO2)/fraction of inspiratory oxygen concentration (FiO2) ratio of less than 300 mmHg. Management involves measurements to improve oxygenation and provide mechanical ventilation to assist breathing. The typical manifestation of ARDS is diffuse lung involvement, which affects multiple lobes symmetrically. Here, we report an unusual case of ARDS in a 53-year-old female who was brought into the hospital in an unresponsive state, exhibiting hypoxic and hypotension requiring intubation. Subsequent imaging revealed a distinctive pattern: the preservation of the right middle lobe, diverging from the conventional diffuse pulmonary affliction. This case underscores the need for clinical vigilance and adaptability, as such atypical presentations can confound diagnosis and management, posing unique clinical challenges. This case highlights the importance of recognizing ARDS' diverse presentations. Moreover, understanding the mechanisms behind the lobar sparing could provide greater insight into the disease heterogeneity and guide tailored therapeutic approaches. The imperative for further research into these uncommon presentations is clear, as it may be vital to improving outcomes for a broader spectrum of ARDS patients.

Baicalin and lung diseases

Studies focusing on natural products have been conducted worldwide, and the results suggest that their natural ingredients effectively treat a wide range of illnesses. Baicalin (BIA) is a glycoside derived from the flavonoid baicalein present in Scutellaria baicalensis of the Lamiaceae family. Interestingly, BIA has been shown to protect the lungs in several animal models used in numerous studies. Therefore, we fully analyzed the data of the studies that focused on BIA's lung protective function against various injuries and included them in this review. Interestingly, BIA exhibits promising effects against acute lung injury, lung fibrosis, pulmonary embolism, and lung remodelling associated with COPD, LPS, and paraquat insecticide. BAI exhibits anticancer activity against lung cancer. Additionally, BIA potently attenuates lung damage associated with infections. BIA primarily exerts its therapeutic effects by suppressing inflammation, oxidative stress immune response, and apoptosis pathways. Nrf2/HO-1, PI3K/Akt, NF-κB, STAT3, MAPKs, TLR4, and NLRP3 are important targets in the pulmonary therapeutic effects of BIA on different lung disease models. Consequently, we recommend using it in future potential clinical applications, its contribution to treatment guidelines, and translating its promising effects to clinical practice in lung diseases.

Value of C-reactive protein/albumin ratio in predicting the development of preoperative oxygenation impairment in patients with Stanford type-B acute aortic dissection

Objectives

We aimed to assess the predicting value of C-reactive protein (CRP)/albumin ratio (CAR) in the development of Oxygenation impairment (OI) in the patients with Stanford type-B acute aortic dissection (AAD).

Methods

This study included 133 patients (age = 58.8 ± 12.0 years, median age = 61 years, Male/Female = 117/16) diagnosed as Stanford type-B AAD accompanied by hypertension from July 2012 to May 2020. Clinical data were retrospectively extracted from the database. The patients in this study were divided into OI group (oxygenation index ≤ 200) and non-OI group (oxygenation index > 200). Clinical characteristics in both groups were compared, and predicting value of CAR in the development of OI was assessed.

Results

Patients in OI group had higher peak body temperature (37.94 ± 0.62 vs. 37.67 ± 0.51 ℃, P =.010), higher levels of serum CRP (41.74 ± 27.71 vs 15.21 ± 19.66 mg/L, P =.000) and plasma B-type natriuretic peptide (292.14 ± 251.11 vs 179.80 ± 241.27 ng/L, P =.016), lower levels of albumin (34.00 ± 5.14 vs 37.72 ± 5.24 g/L, P =.000), and higher CAR (1.27 ± 0.89 vs 0.41 ± 0.53, P =.000). In multivariate regression analysis, CAR (odds ratio: 5.215, 95 % CI: 2.682; 10.137, P =.000) and the peak body temperature (odds ratio: 2.905, 95 % CI: 1.255; 6.724, P =.013) could significantly predict the OI development. The AUC for CAR was 0.831 (95 % CI: 0.756-0.907). An optimal cutoff value for CAR for predicting OI was ≥ 0.70, with a sensitivity of 67.5 % and a specificity of 88.2 %.

Conclusions

Compared with CRP or albumin alone, the CAR might be a more accurate marker in predicting OI development in Stanford type-B AAD.

A Case Report of Acute Respiratory Distress Syndrome From Cannabis and Amphetamine Use

Illicit drug usage (IDU) is a big challenge in clinical practice, with increasing incidence in the last decades. Daily, clinicians encounter a wide variety of complications related to IDU. Common infections related to illicit drugs are infective endocarditis, abscesses, osteomyelitis, pneumonia, HIV, hepatitis C, and B. Other rare complications could happen like leukoencephalopathy, IDU-related lung injury, and acute respiratory distress syndrome (ARDS) which is a severe and potentially life-threatening condition characterized by the sudden onset of respiratory failure, often necessitating mechanical ventilation. While the most common etiologies of ARDS are related to infections and sepsis, there is emerging evidence that substance abuse can also be associated with the development of ARDS with unclear mechanisms. IDU-related lung injury is a rare entity with few cases reported in the literature. Its management usually involves supportive care, including mechanical ventilation, oxygen therapy, and close monitoring of fluid balance. We present a case of a 25-year-old male presented with ARDS and multiorgan failure related to methamphetamine and cannabis abuse.

A 'one stone, two birds' approach with mesenchymal stem cells for acute respiratory distress syndrome and Type II diabetes mellitus

This review explores the intricate relationship between acute respiratory distress syndrome (ARDS) and Type II diabetes mellitus (T2DM). It covers ARDS epidemiology, etiology and pathophysiology, along with current treatment trends and challenges. The lipopolysaccharides (LPS) role in ARDS and its association between non-communicable diseases and COVID-19 are discussed. The review highlights the therapeutic potential of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) for ARDS and T2DM, emphasizing their immunomodulatory effects. This review also underlines how T2DM exacerbates ARDS pathophysiology and discusses the potential of hUC-MSCs in modulating immune responses. In conclusion, the review highlights the multidisciplinary approach to managing ARDS and T2DM, focusing on inflammation, oxidative stress and potential therapy of hUC-MSCs in the future.

An Elderly Case of Altered Metabolic Profile Presenting With Respiratory Distress: A Radical Display

Acute respiratory distress syndrome (ARDS) is a pulmonary pathology that itself can harm and further lead to many other significant hazardous sequelae. Pulmonary vasculature can be distressed by several diseases, but among all the causes, sepsis is one of the main culprits. Its consequences include significant alveolar injury, refractory hypoxemia, ventilation-perfusion mismatch, and destruction of the alveolar-capillary membrane. Dyspnea with diffuse infiltration on a chest X-ray is the most prevalent clinical symptom. Here, we discuss a case of a 62-year-old male patient who presents with ARDS and metabolic anomalies. The patient was treated medically with drug regimens.

Acute type B aortic dissection with multiple cholesterol embolism: an autopsy case report

Background

Most cases of cholesterol embolism are known to be triggered by cardiac catheterization, cardiovascular surgery, anticoagulation, or fibrinolytic therapy; however, spontaneous cases after aortic dissection are rare. In this report, we describe a case of cholesterol embolism after type B aortic dissection, which rapidly developed into multiple organ failure and death.

Case summary

A 65-year-old man with untreated hypertension was admitted to our hospital with sudden back pain and diagnosed with type B aortic dissection. The patient experienced a rapid progression of inflammation and developed respiratory and renal failure, despite computed tomography showing no obvious progression of dissection. We attributed them to a cytokine storm and acute respiratory distress syndrome, but steroid pulse therapy did not alleviate the symptoms. Finally, the patient died on Day 6 after admission, and an autopsy was performed, which revealed cholesterol crystal occlusions in the kidney, spleen, and the left lower leg. The lumen in the aorta is filled with atheroma and thrombus, and we suspect that aortic dissection triggered failure of the aortic plaques and released cholesterol crystals to distal arteries that led to cholesterol embolism.

Discussion

We experienced a patient with a type B aortic dissection that led to cholesterol embolism and rapid progression of respiratory and renal failure, resulting in death. The aortic dissection combined with cholesterol embolism was considered to trigger the subsequent severe inflammation, leading to rapid respiratory and renal failure. Our case points to the possibility that cholesterol embolism can extensively escalate inflammation after aortic dissection.

Postoperative pulmonary complications in patients undergoing aortic surgery: A single-center retrospective study

Postoperative pulmonary complications (PPCs) are among the most common complications after cardiovascular surgery. This study aimed to explore the real incidence of and risk factors for PPC in patients with acute type A aortic dissection (ATAAD) who underwent total aortic arch replacement combined with the frozen elephant trunk (TAR + FET). In total, 305 ATAAD patients undergoing TAR + FET from January 2021 to August 2022 in a single-center were divided into PPCs or non-PPCs group. The incidence of PPCs was calculated, risk factors of PPCs were analyzed, and postoperative outcomes were compared between these 2 groups. The incidence of any PPC was 29.2%. And the incidence of respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, acute respiratory distress syndrome, aspiration pneumonitis, pulmonary edema and bronchospasm was 23.0%, 12.5%, 10.5%, 1.0%, 0.7%, 1.0%, 0%, 0.7%, 0%, respectively. The logistic regression analysis revealed that the history of diabetes, history of renal dysfunction, preoperative SpO2 <90%, cardiopulmonary bypass duration, fresh frozen plasma volume and platelet concentrates volume were independent risk factors for PPCs. Among 2 groups, postoperative ventilation duration, postoperative length of stay in intensive care unit and hospital were (73.5 ± 79.0 vs 24.8 ± 35.2 hours; P < .001), (228.3 ± 151.2 vs 95.2 ± 72.0 hours; P < .001) and (17.9 ± 8.8 vs 11.5 ± 6.2 days; P < .001). There was no difference between 2 groups of in-hospital mortality rate. Additionally, other short-term outcomes were also significantly poorer in patients with PPCs. PPCs are common in ATAAD patients undergoing TAR + FET, and could be multifactorial. PPCs occurrence are associated with poor patient outcomes postoperatively and worth further investigation.

NMDARs antagonist MK801 suppresses LPS-induced apoptosis and mitochondrial dysfunction by regulating subunits of NMDARs via the CaM/CaMKII/ERK pathway

Lipopolysaccharide (LPS) displays a robust immunostimulatory ability upon Toll-like receptor 4 (TLR4) recognition. N-methyl-D-aspartate receptors (NMDARs) are highly compartmentalized in most cells and implicated in various inflammatory disorders. However, the relationship between TLR4 and NMDARs has not been explored deeply. This study aimed to examine the role of NMDARs and its specific inhibitor MK801 in LPS-treated endothelial cell dysfunction and the related mechanism in vivo and in vitro. The results showed that pre-treatment with MK801 significantly decreased LPS-induced cell death, cellular Ca²⁺, cellular reactive oxygen species, and glutamate efflux. Moreover, MK801 restrained LPS-induced mitochondrial dysfunction by regulating mitochondrial membrane potential and mitochondrial Ca²⁺ uptake. The oxygen consumption, basal and maximal respiration rate, and ATP production in LPS-treated HUVECs were reversed by MK801 via regulating ATP synthesis-related protein SDHB2, MTCO1, and ATP5A. The molecular pathway involved in MK801-regulated LPS injury was mediated by phosphorylation of CaMKII and ERK and the expression of MCU, MCUR1, and TLR4. LPS-decreased permeability in HUVECs was improved by MK801 via the Erk/ZO-1/occluding/Cx43 axis. Co-immunoprecipitation assay and western blotting showed three subtypes of NMDARs, NMDAζ1, NMDAε2, and NMDAε4 were bound explicitly to TLR4, suppressed by LPS, and promoted by MK801. Deficiency of NMDAζ1, NMDAε2, or NMDAε4 induced cell apoptosis, Ca²⁺ uptake, ROS production, and decreased basal and maximal respiration rate, and ATP production, suggesting that NMDARs integrity is vital for cell and mitochondrial function. In vivo investigation showed MK801 improved impairment of vascular permeability, especially in the lung and mesentery in LPS-injured mice. Our study displayed a novel mechanism and utilization of MK801 in LPS-induced ECs injury and permeability.

Protocol for clinical diagnosis and empiric treatment of pulmonary tuberculosis in severely burned patients: observations and literature review

Introduction

Reactivation of pulmonary tuberculosis is a prevalent concomitant infection and cause for mortality in burns patients in Sub-Saharan Africa. First line laboratory diagnostic studies for pulmonary tuberculosis are often negative in these patients and if relied on, result in high mortality. The purpose of this report is to share our experience with a novel protocol of empiric treatment of clinically suspected pulmonary tuberculosis in severely burned patients with negative GeneXpert tests in a tertiary burns centre and to present a brief literature review on the topic.

Methods

A retrospective chart review of all patients, who sustained thermal injury with an inhalation component, with negative GeneXpert tests who were treated empirically for pulmonary tuberculosis over a five-year period (2015-2020) was performed. Additionally, a literature search was performed on Medline (PubMed), Cochrane and Google Scholar databases.

Results

Over the five-year period, 20 patients with suspected pulmonary tuberculosis and severe burns requiring ventilation were managed according to the protocol and all survived to discharge. The literature search identified six factors that explain the consequence of pulmonary tuberculosis in severely burned patients and provide a hypothesis for the negative laboratory studies encountered.

Conclusion

There was an improved outcome for patients with the clinical diagnosis of reactivation of pulmonary tuberculosis when they were started on empirical pulmonary tuberculosis treatment. There are several potential mechanisms that can contribute to reactivation of pulmonary tuberculosis in susceptible severely burned patients. The GeneXpert test should not be relied upon in these patients for a diagnosis, but rather all other clinical evidence should inform management.

Lay Summary

From the current literature evidence most patients who have severe burns complicated by a secondary infection known as pulmonary (lung) tuberculosis, die as a result. The purpose of this report is to share our experience with treatment of pulmonary tuberculosis during a five-year period, from 2015 to 2020, in a specialized adult tertiary burn center. Severely burned patients who were suspected of having pulmonary tuberculosis and received treatment despite having negative laboratory tests for pulmonary tuberculosis, had a better survival rate than expected. A brief literature review on the topic of pulmonary tuberculosis and severe burns was done to investigate causes for reactivation of pulmonary tuberculosis and negative laboratory studies in these patients.The literature search identified the following factors that can potentially affect the reactivation of pulmonary tuberculosis in severely burned patients: decreased immune system; secondary infections; low blood albumin(protein) levels; decreased clearance of bacteria from the airways, the development of pulmonary tuberculosis biofilms (capsules that protect the bacteria from chemicals and antibiotics) and the role of a fat molecule called phosphatidylinositol mannoside in pulmonary tuberculosis.In conclusion, the pulmonary tuberculosis test should not be relied upon in these patients, but rather all the clinical evidence such X-ray changes in association with difficulty to wean the patient off the ventilator should be used to inform treatment choice.

A Propensity-Matched Analysis of Tranexamic Acid and Acute Respiratory Distress Syndrome in Trauma Patients

INTRODUCTION

Tranexamic acid (TXA) protects the vasculature endothelium after hemorrhage, resulting in a decreased capillary leak. These properties may protect patients receiving TXA from acute respiratory distress syndrome (ARDS), however, clinical studies have yet to examine this topic. We hypothesized that trauma patients receiving TXA would have lower incidence of ARDS.

METHODS

This was a retrospective review of adult (18+ y) patients who presented to a large Level I trauma center with an injury severity score ≥ 16 from admit years 2012-2020. Propensity matching was employed to examine how TXA administration is associated with ARDS.

RESULTS

There were a total of 2751 patients meeting study criteria, with 162 (5.9%) received TXA. Of the 162 patients that received TXA, only 12 (7.4%) received pre-hospital TXA, while 4 (2.5%) received TXA both pre-hospital and in hospital. Of the 63 patients developing ARDS, 62 (98.4%) did not receive TXA. After propensity matching, 304 patients remained, with 152 in each cohort. The incidence of ARDS (P = 0.08), pneumonia (P = 0.68), any pulmonary complication (P = 0.33), and mortality (P = 0.37) were not different in patients receiving TXA on propensity matching.

CONCLUSIONS

TXA did not protect trauma patients from pulmonary complications; however, nearly all patients developing ARDS did not receive TXA. Larger studies should examine this relationship to improve understanding of therapies that may prevent ARDS.

A Case of Severe Acute Respiratory Distress Syndrome Secondary to Atypical Amniotic Fluid Embolism

Acute respiratory distress syndrome (ARDS) is a noncardiogenic pulmonary edema that leads to acute respiratory distress. It remains one of the major diagnoses requiring ICU admission and mechanical ventilation. We present a case of a 25-year-old gravida 3 para 2 female who was admitted for uncomplicated 38-week pregnancy and delivered a healthy male infant but developed acute onset dyspnea six hours after vaginal delivery. She required mechanical ventilation four hours after the onset of respiratory distress and had to be transferred to a higher level facility for extracorporeal membrane oxygenation (ECMO) within 24 hours of the symptom onset. She was diagnosed with severe ARDS. Even though she missed the other typical feature of amniotic fluid embolism, atypical amniotic fluid embolism remained the most likely explanation for her symptoms after the other causes of ARDS were excluded.

MAGI1 inhibits interferon signaling to promote influenza A infection

We have shown that membrane-associated guanylate kinase with inverted domain structure-1 (MAGI1), a scaffold protein with six PSD95/DiscLarge/ZO-1 (PDZ) domains, is involved in the regulation of endothelial cell (EC) activation and atherogenesis in mice. In addition to causing acute respiratory disease, influenza A virus (IAV) infection plays an important role in atherogenesis and triggers acute coronary syndromes and fatal myocardial infarction. Therefore, the aim of this study is to investigate the function and regulation of MAGI1 in IAV-induced EC activation. Whereas, EC infection by IAV increases MAGI1 expression, MAGI1 depletion suppresses IAV infection, suggesting that the induction of MAGI1 may promote IAV infection. Treatment of ECs with oxidized low-density lipoprotein (OxLDL) increases MAGI1 expression and IAV infection, suggesting that MAGI1 is part of the mechanistic link between serum lipid levels and patient prognosis following IAV infection. Our microarray studies suggest that MAGI1-depleted ECs increase protein expression and signaling networks involve in interferon (IFN) production. Specifically, infection of MAGI1-null ECs with IAV upregulates expression of signal transducer and activator of transcription 1 (STAT1), interferon b1 (IFNb1), myxovirus resistance protein 1 (MX1) and 2'-5'-oligoadenylate synthetase 2 (OAS2), and activate STAT5. By contrast, MAGI1 overexpression inhibits Ifnb1 mRNA and MX1 expression, again supporting the pro-viral response mediated by MAGI1. MAGI1 depletion induces the expression of MX1 and virus suppression. The data suggests that IAV suppression by MAGI1 depletion may, in part, be due to MX1 induction. Lastly, interferon regulatory factor 3 (IRF3) translocates to the nucleus in the absence of IRF3 phosphorylation, and IRF3 SUMOylation is abolished in MAGI1-depleted ECs. The data suggests that MAGI1 inhibits IRF3 activation by maintaining IRF3 SUMOylation. In summary, IAV infection occurs in ECs in a MAGI1 expression-dependent manner by inhibiting anti-viral responses including STATs and IRF3 activation and subsequent MX1 induction, and MAGI1 plays a role in EC activation, and in upregulating a pro-viral response. Therefore, the inhibition of MAGI1 is a potential therapeutic target for IAV-induced cardiovascular disease.

Andrographolide Suppresses Expressions of Coagulation and Fibrinolytic Inhibition-Related Factors in LPS-Induced Alveolar Epithelial Cell Type II via NF-κB Signal Pathway In Vitro

Background

Andrographolide (Andro) has been confirmed to ameliorate alveolar hypercoagulation and fibrinolysis inhibition via NF-κB pathway in acute respiratory distress syndrome (ARDS), but the specific target of Andro is unknown.

Purpose

Our aim is to explore the specific target of Andro through which the drug exerted its effects on alveolar hypercoagulation and fibrinolytic inhibition in LPS-induced ARDS.

Methods

AECII was treated with different doses of Andro for 1 h, and then stimulated with LPS for 24 h. Expressions of tissue factor (TF), plasminogen activator inhibitor (PAI)-1 and tissue factor pathway inhibitor (TFPI) were detected. Concentrations of thrombin-antithrombin complex (TAT), pro-collagen type III peptide (PIIIP), antithrombin III (ATIII) and activated protein C (APC) in cell supernatant were measured by enzyme linked immunosorbent assay (ELISA). NF-κB signaling pathways activation was simultaneously determined. AECII with p65 down-/over-expression were used as control.

Results

Andro effectively inhibited TF and PAI-1 and promoted TFPI expressions on AECII induced by LPS stimulation. Andro also significantly suppressed the productions of TAT and PIIIP but promoted ATIII and APC secretions from the LPS-treated cell. Furthermore, Andro application obviously inhibited NF-κB signaling pathway activation provoked by LPS, as shown by decreased level of phosphorylation (p‑)-IKKβ/IKKβ, p-p65/p65 and p65 DNA binding activity. The effects of Andro on those factors were obviously strengthened by down- but were weakened by up-regulation of p65 gene in AECII cell.

Conclusions

Our data demonstrates that targeting AECII is the mechanism by which Andro ameliorates alveolar hypercoagulaiton and fibrinolytic inhibition via NF-κB pathway in ARDS. Andro is worth to be clinically further studied in ARDS treatment.

Therapeutic hypothermia attenuates physiologic, histologic, and metabolomic markers of injury in a porcine model of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a lung injury characterized by noncardiogenic pulmonary edema and hypoxic respiratory failure. The purpose of this study was to investigate the effects of therapeutic hypothermia on short-term experimental ARDS. Twenty adult female Yorkshire pigs were divided into four groups (n = 5 each): normothermic control (C), normothermic injured (I), hypothermic control (HC), and hypothermic injured (HI). Acute respiratory distress syndrome was induced experimentally via intrapulmonary injection of oleic acid. Target core temperature was achieved in the HI group within 1 h of injury induction. Cardiorespiratory, histologic, cytokine, and metabolomic data were collected on all animals prior to and following injury/sham. All data were collected for approximately 12 h from the beginning of the study until euthanasia. Therapeutic hypothermia reduced injury in the HI compared to the I group (histological injury score = 0.51 ± 0.18 vs. 0.76 ± 0.06; p = 0.02) with no change in gas exchange. All groups expressed distinct phenotypes, with a reduction in pro-inflammatory metabolites, an increase in anti-inflammatory metabolites, and a reduction in inflammatory cytokines observed in the HI group compared to the I group. Changes to respiratory system mechanics in the injured groups were due to increases in lung elastance (E) and resistance (R) (ΔE from pre-injury = 46 ± 14 cmH₂ O L^-1 , p < 0.0001; ΔR from pre-injury: 3 ± 2 cmH₂ O L^-1  s^- , p = 0.30) rather than changes to the chest wall (ΔE from pre-injury: 0.7 ± 1.6 cmH₂ O L^-1 , p = 0.99; ΔR from pre-injury: 0.6 ± 0.1 cmH₂ O L^-1  s^- , p = 0.01). Both control groups had no change in respiratory mechanics. In conclusion, therapeutic hypothermia can reduce markers of injury and inflammation associated with experimentally induced short-term ARDS.

Presepsin as a Novel Biomarker in predicting In-hospital Mortality in Patients With COVID-19 Pneumonia

OBJECTIVES

Different biomarkers such as C-reactive protein (CRP), serum ferritin and D-dimer are used in prognostic assessment of patients with COVID-19 pneumonia. Presepsin (PSP) is a soluble CD14 subtype that has recently been proposed as a novel biomarker in patients with sepsis. The aim of the current study was to detect the relation of PSP to the outcome of COVID-19 as well as its relation to other inflammatory biomarkers.

METHODS

This multicenter retrospective observational study was conducted in Saudi Arabia and Misr International Hospital, Egypt, from January 2021 to May 2021. Hospitalised patients who had positive throat swab of SARS-CoV-2 and radiological evidence of viral pneumonia (moderate and severe forms) were included in the study. Demographics and clinical features, as well as laboratory parameters, including serum ferritin, CRP, D-dimer and PSP, of enrolled patients were retrospectively collected. Pneumonia severity index (PSI) was used to evaluate the severity of pneumonia.

RESULTS

A total of 202 hospitalised patients who were diagnosed with COVID-19 pneumonia and tested positive for SARS-CoV-2 RNA were enrolled in our study. Of 202 hospitalised patients, 67 (33.17%) required intensive care unit (ICU) admission. A total of 176 (87.1%) patients survived and were discharged, whereas 26 (12.9%) patients did not survive. PSP level was found to be significantly elevated in nonsurvivor versus survivor group (median [IQR] 978.5 [755.8-1400] vs 516.5 [343.3-720], P<0.001) as well as in ICU versus non-ICU patients (median [IQR] 800 [631-1200] and 446 [320-626], respectively) (P<0.001). Elevated levels were also found to be associated with increased length of hospital stay. Levels above 775 pg/mL were found to be associated with in-hospital mortality (specificity 80%, sensitivity 73%).

CONCLUSION

Elevated PSP levels indicated poor outcomes in hospitalised patients with COVID-19 pneumonia and were associated with in-hospital mortality.

Berberine Suppresses Leukocyte Adherence by Downregulating CX3CL1 Expression and Shedding and ADAM10 in Lipopolysaccharide-Stimulated Vascular Endothelial Cells

Berberine exerts therapeutic effects in inflammation-associated diseases. In a lipopolysaccharide (LPS)-induced endotoxemic acute lung injury (ALI) rat model, berberine alleviated lung injury through different anti-inflammatory mechanisms; however, treatment effects on CX3CL1 expression and shedding remain to be examined. As these processes play important roles in promoting the binding of leukocytes to the endothelium, the CX3CL1/CX3CR1 axis and its related pathways may serve as potential targets for the clinical treatment of ALI. The anti-inflammatory effects of berberine were investigated in LPS-stimulated rats, human umbilical cord vein endothelial cells (HUVECs), and THP-1 monocytic cells. Cx3cl1 expression in rat pulmonary tissues was examined using immunohistochemistry. CX3CL1, CX3CR1, RELA, STAT3, and ADAM10 levels were examined using Western blotting. CX3CL1 and ADAM10 mRNA levels were examined using quantitative real-time polymerase chain reaction. Soluble fractalkine levels in LPS-stimulated rats and HUVECs were examined using the enzyme-linked immunosorbent assay. Berberine significantly mitigated the LPS-induced upregulation of fractalkine and soluble fractalkine in rats and cultured HUVECs. Berberine mitigated the LPS-induced activation of the NF-κB and STAT3 signaling pathways. In THP-1 cells, berberine mitigated the LPS-induced upregulation of CX3CR1. Furthermore, the membrane expression of ADAM10 in LPS-stimulated HUVECs was suppressed by the berberine treatment. Berberine dose-dependently inhibited the LPS-induced activation of the CX3CL1/CX3CR1 axis and fractalkine shedding through ADAM10. These findings reveal a novel molecular mechanism underlying the inhibitory effect of berberine on monocyte adherence to the endothelium during inflammation.

Preoperative acute lung injury and oxygenation impairment occurred in the patients with acute aortic dissection

Acute lung injury (ALI) and oxygenation impairment (OI) frequently occur in the patients with acute aortic dissection (AAD), which may necessitate mechanical ventilation and result in adverse outcomes. This paper aims to increase clinicians’ awareness of the severe respiratory complications in the patients with AAD, and provide the overview of the epidemiology, adverse outcomes, pathogenesis, predictive markers and therapeutic modalities of the concurrent conditions. Currently, it is considered that inflammatory response plays a great role in the pathogenesis of ALI and OI in the patients with AAD, but the definite pathogenesis remains unclear. Given the great importance of the prediction of the occurrence of the severe respiratory complication at a very early stage, some inflammatory biomarkers have been investigated to predict the occurrence of ALI and OI in several studies. C-reactive protein was found to have a significant predictive effect for the development of ALI and OI. Early use of beta-blockers and the use of bindarit could prevent the occurrence of OI and ALI. Ulinastatin could also improve oxygenation in the patients with type-A AAD. Prevention and management of ALI and OI in AAD remain a great challenge. The definite pathogenesis should be clearly clarified and further studies should be performed to look for potential effective way to predict and manage the severe respiratory conditions.

H5N1 infection impairs the alveolar epithelial barrier through intercellular junction proteins via Itch-mediated proteasomal degradation

The H5N1 subtype of the avian influenza virus causes sporadic but fatal infections in humans. H5N1 virus infection leads to the disruption of the alveolar epithelial barrier, a pathologic change that often progresses into acute respiratory distress syndrome (ARDS) and pneumonia. The mechanisms underlying this remain poorly understood. Here we report that H5N1 viruses downregulate the expression of intercellular junction proteins (E-cadherin, occludin, claudin-1, and ZO-1) in several cell lines and the lungs of H5N1 virus-infected mice. H5N1 virus infection activates TGF-β-activated kinase 1 (TAK1), which then activates p38 and ERK to induce E3 ubiquitin ligase Itch expression and to promote occludin ubiquitination and degradation. Inhibition of the TAK1-Itch pathway restores the intercellular junction structure and function in vitro and in the lungs of H5N1 virus-infected mice. Our study suggests that H5N1 virus infection impairs the alveolar epithelial barrier by downregulating the expression of intercellular junction proteins at the posttranslational level.

Prolonged Methylprednisolone Therapy in the Fibro-Proliferative Phase of Acute Respiratory Distress Syndrome

Late-stage acute respiratory distress syndrome (ARDS), primarily associated with fibro-proliferative changes, may occur in many patients. This stage, where ARDS progresses to the point of being incurable, involves a complicated and long clinical course that may give rise to functional loss; it has therefore been a major focus of both preventive and therapeutic strategies. In the present case report, the successful use of prolonged methylprednisolone therapy in the fibro-proliferative phase of ARDS is described in a patient who developed pneumonia and secondary ARDS after terminating a pregnancy due to preeclampsia. Methylprednisolone therapy, which was initiated at a daily dosage of 1 mg/kg, was tapered down based on the clinical and radiologic status of the patient and was terminated at the end of the sixth month. Follow-up imaging studies and pulmonary function tests performed at the end of the first and sixth months showed marked improvements and the patient experienced no systemic adverse effects despite long-term steroid therapy.

Adverse reaction of methylprednisolone pulse therapy: Acute respiratory distress syndrome

Methylprednisolone pulse therapy has significant anti-inflammatory effects in multiple sclerosis. Acute respiratory distress syndrome as a probable adverse effect of methylprednisolone pulse therapy in MS patients should be considered.

Polymer-based nano-therapies to combat COVID-19 related respiratory injury: progress, prospects, and challenges

The recent coronavirus disease-2019 (COVID-19) outbreak has increased at an alarming rate, representing a substantial cause of mortality worldwide. Respiratory injuries are major COVID-19 related complications, leading to poor lung circulation, tissue scarring, and airway obstruction. Despite an in-depth investigation of respiratory injury's molecular pathogenesis, effective treatments have yet to be developed. Moreover, early detection of viral infection is required to halt the disease-related long-term complications, including respiratory injuries. The currently employed detection technique (quantitative real-time polymerase chain reaction or qRT-PCR) failed to meet this need at some point because it is costly, time-consuming, and requires higher expertise and technical skills. Polymer-based nanobiosensing techniques can be employed to overcome these limitations. Polymeric nanomaterials have the potential for clinical applications due to their versatile features like low cytotoxicity, biodegradability, bioavailability, biocompatibility, and specific delivery at the targeted site of action. In recent years, innovative polymeric nanomedicine approaches have been developed to deliver therapeutic agents and support tissue growth for the inflamed organs, including the lung. This review highlights the most recent advances of polymer-based nanomedicine approaches in infectious disease diagnosis and treatments. This paper also focuses on the potential of novel nanomedicine techniques that may prove to be therapeutically efficient in fighting against COVID-19 related respiratory injuries.

H1N1 Influenza Virus Cross-Activates Gli1 to Disrupt the Intercellular Junctions of Alveolar Epithelial Cells

Influenza A virus (IAV) primarily infects the airway and alveolar epithelial cells and disrupts the intercellular junctions, leading to increased paracellular permeability. Although this pathological change plays a critical role in lung tissue injury and secondary infection, the molecular mechanism of IAV-induced damage to the alveolar barrier remains obscure. Here, we report that Gli1, a transcription factor in the sonic hedgehog (Shh) signaling pathway, is cross-activated by the MAP and PI3 kinase pathways in H1N1 virus (PR8)-infected A549 cells and in the lungs of H1N1 virus-infected mice. Gli1 activation induces Snail expression, which downregulates the expression of intercellular junction proteins, including E-cadherin, ZO-1, and Occludin, and increases paracellular permeability. Inhibition of the Shh pathway restores the levels of Snail and intercellular junction proteins in H1N1-infected cells. Our study suggests that Gli1 activation plays an important role in disrupting the intercellular junctions and in promoting the pathogenesis of H1N1 virus infections.

Cerium oxide nanoparticle delivery of microRNA-146a for local treatment of acute lung injury

Acute respiratory distress syndrome (ARDS) is a devastating pulmonary disease with significant in-hospital mortality and is the leading cause of death in COVID-19 patients. Excessive leukocyte recruitment, unregulated inflammation, and resultant fibrosis contribute to poor ARDS outcomes. Nanoparticle technology with cerium oxide nanoparticles (CNP) offers a mechanism by which unstable therapeutics such as the anti-inflammatory microRNA-146a can be locally delivered to the injured lung without systemic uptake. In this study, we evaluated the potential of the radical scavenging CNP conjugated to microRNA-146a (termed CNP-miR146a) in preventing acute lung injury (ALI) following exposure to bleomycin. We have found that intratracheal delivery of CNP-miR146a increases pulmonary levels of miR146a without systemic increases, and prevents ALI by altering leukocyte recruitment, reducing inflammation and oxidative stress, and decreasing collagen deposition, ultimately improving pulmonary biomechanics.

A Review of the Evidence for Corticosteroids in COVID-19

OBJECTIVE

To review available evidence on corticosteroids in acute respiratory distress syndrome (ARDS), Coronavirus Disease 2019 (COVID-19), and other viral pneumonias.

DATA SOURCES

A literature search of MEDLINE, PubMed and clinicaltrials.gov was performed to identify studies between 1980 to 2020 using the following search terms: corticosteroids, COVID19, severe respiratory syndrome coronavirus 2 (SARS-CoV-2), Middle East respiratory syndrome-related coronavirus (MERS-CoV), and influenza. Pre-printed articles were also reviewed at medRxiv.org.

DATA ANALYSIS

Corticosteroids were not recommended early in the COVID-19 pandemic outside of the use for concomitant indications (i.e. ARDS, septic shock) as they have been associated with delayed time to viral clearance in other viral pneumonias. A randomized trial showed a mortality benefit with dexamethasone in COVID-19. Guidelines have been updated to include a strong recommendation for their use in COVID-19 in those hospitalized requiring supplemental oxygen or mechanical ventilation.

CONCLUSION

Based on data from available randomized trials, patients that require respiratory support or mechanical ventilation benefit from corticosteroid therapy. Corticosteroids are an inexpensive and readily available therapy that should be standard of care in hospitalized COVID-19 patients requiring respiratory support.

Ethnic and age-specific acute lung injury/acute respiratory distress syndrome risk associated with angiotensin-converting enzyme insertion/deletion polymorphisms, implications for COVID-19: A meta-analysis

BACKGROUND

The reported association between an insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene and the risk for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) remains controversial despite the publication of four meta-analyses on this topic. Here, we updated the meta-analysis with more studies and additional assessments that include adults and children within the context of the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

Sixteen articles (22 studies) were included. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using three genetic models (allele, recessive and dominant), in which ARDS patients were compared with non-ARDS patients (A1) and healthy controls (A2). Mortality outcomes were also assessed (A3). The influence of covariates was examined by meta-regression. Bonferroni correction was performed for multiple pooled associations. Subgroup analyses based on ethnicity (Asians, Caucasians) and life stage (adults, children) were conducted. Heterogeneity was addressed with outlier treatment.

RESULTS

This meta-analysis generated 68 comparisons, 21 of which were significant. Of the 21, four A1 and three A3 highly significant (Pa = 0.00001-0.0008) outcomes withstood Bonferroni correction. For A1, allele and recessive associations were found in overall (OR 0.49, 95% CI 0.39-0.61), Caucasians (OR 0.46, 95% CI 0.35-0.61) and children (ORs 0.49-0.66, 95% CI 0.33-0.84) analyses. For A3, associations were found in overall (dominant: OR 0.45, 95% CI 0.29-0.68) and Asian subgroup (allele/ dominant: ORs 0.31-0.39, 95% CIs 0.18-0.63) analyses. These outcomes were either robust, or statistically powered or both and uninfluenced by covariates.

CONCLUSIONS

Significant associations of the ACE I/D polymorphism with the risk of ALI/ARDS were indicated in Caucasians and children as well as in Asians in mortality analysis. These findings were underpinned by high significance, high statistical power and robustness. ACE genotypes may be useful for ALI/ARDS therapy for patients with COVID-19.

Venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome due to an acute type B aortic dissection: a case report

Acute type B aortic dissection is sometimes complicated by acute respiratory failure requiring mechanical ventilation. Herein, we describe our experience in a rare acute type B aortic dissection-associated respiratory failure case culminating in acute respiratory distress syndrome. The patient was a 45-year-old man admitted with a complaint of sudden chest pain radiating to his back. On computed tomography, an acute type B aortic dissection was diagnosed. He had no dyspnea on admission, but his respiratory function subsequently deteriorated, and severe acute respiratory distress syndrome was diagnosed on Day 4. Venovenous extracorporeal membrane oxygenation with anticoagulation plus continuous renal replacement therapy for oliguria improved the oxygenation, and the patient was weaned from the extracorporeal membrane oxygenation on Day 8. This patient fully recovered without worsening the aortic dissection, using venovenous extracorporeal membrane oxygenation with anticoagulation plus a continuous renal replacement therapy.

Diammonium glycyrrhizinate lipid ligand ameliorates lipopolysaccharide-induced acute lung injury by modulating vascular endothelial barrier function

The aim of the present study was to investigate the effects of diammonium glycyrrhizinate lipid ligand (DGLL) treatment on acute lung injury (ALI) and pulmonary edema induced by lipopolysaccharide (LPS) in Sprague-Dawley rats. Rats orally received 30, 60 and 120 mg/kg DGLL. After 1 h, the rat ALI model was established by LPS (10 mg/kg) intraperitoneal injection. After 6 h, lung injury was evaluated using hematoxylin and eosin staining techniques. Pulmonary edema was evaluated using lung wet-dry weight ratio, protein concentrations in the bronchoalveolar lavage fluid (BALF) and Evans blue (EB) extravasation in lung tissue. The expression levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in lung tissues were measured using ELISA. Myeloperoxidase (MPO) expression levels were detected by immunohistochemical staining. Western blotting was used to measure the expression level changes of intercellular adhesion molecule (ICAM)-1, as well as adherent and tight junction proteins, including vascular endothelial (VE)-cadherin, zonula occludens (ZO)-1, occludin and junctional adhesion molecule (JAM)-1 that were associated with pulmonary inflammation and microvascular permeability. DGLL treatment significantly alleviated ALI induced by LPS, which was demonstrated by reduction of MPO-positive cells and expression levels of TNF-α, IL-1β and ICAM-1 in rat lung tissues. In addition, DGLL abrogated LPS-induced pulmonary edema, decreased the protein concentration in BALF and reduced EB extravasation. DGLL also reversed the reduced expression of VE-cadherin and tight junction proteins, including ZO-1, occludin and JAM-1 in the lung tissues caused by LPS. In conclusion, DGLL exhibits a protective effect on LPS-induced rat ALI, which is associated with the inhibition of inflammatory cell infiltration and microvascular barrier disruption. The present results provide a theoretical basis for the application of DGLL for the potential clinical treatment of ALI.

Targeting MALAT1 and miRNA-181a-5p for the intervention of acute lung injury/acute respiratory distress syndrome

BACKGROUND

ALI/ARDS is a severe lung injury leading to refractory respiratory failure, accounting for high morbidity and mortality. However, therapeutic approaches are rather limited. Targeting long non-coding RNA MALAT1 and microRNA miR-181a-5p might be potential option for ALI/ARDS intervention.

OBJECTIVE

We aimed to investigate the role of MALAT and miR-181a-5p in the pathogenesis of ALI/ARDS, and test the therapeutic effects of targeting MALAT and miR-181a-5p for ALI/ARDS intervention in vitro.

METHODS

MALAT1 and miR-181a-5p levels were measured in plasma from ALI/ARDS patients. In vitro human pulmonary microvascular endothelial cell (HPMEC) injury was induced by LPS treatment, and molecular targets of MALAT1 and miR-181a-5p were explored by molecular biology approaches, mainly focusing on cell apoptosis and vascular inflammation. Interaction between MALAT1 and miR-181a-5p was also detected. Finally, the effects of targeting MALAT1 and miR-181a-5p for ALI/ARDS intervention were validated in a rat ALI/ARDS model.

RESULTS

MALAT1 upregulation and miR-181a-5p downregulation were observed in ALI/ARDS patients. Transfection of mimic miR-181a-5p into HPMECs revealed decreased Fas and apoptosis, along with reduced inflammatory factors. Fas was proved to be a direct target of miR-181a-5p. Similar effects were also present upon MALAT1 knockdown. As for the interaction between MALAT1 and miR-181a-5p, MALAT1 knockdown increased miR-181a-5p expression. Knocking down of MALAT1 and miR-181a-5p could both improve the outcome in ALI/ARDS rats.

CONCLUSION

MALAT1 antagonism or miR-181a-5p could both be potential therapeutic strategies for ALI/ARDS. Mechanistically, miR-181a-5p directly inhibits Fas and apoptosis, along with reduced inflammation. MALAT1 negatively regulates miR-181a-5p.

Effect of corticosteroid therapy in the early phase of acute respiratory distress syndrome: a propensity-matched cohort study

BACKGROUND/AIMS

It is unclear whether corticosteroid use in patients with acute respiratory distress syndrome (ARDS) improves survival. This study aimed to investigate whether the administration of corticosteroids to patients in the early phase of moderate to severe ARDS is associated with improved outcomes.

METHODS

We analyzed the data of patients who received corticosteroids within 7 days of the onset of ARDS between June 2006 and December 2015 at a single tertiary teaching hospital. A total of 565 patients admitted with moderate to severe ARDS were eligible. The outcomes of patients treated with methylprednisolone 40 to 180 mg/day or equivalent (n = 404) were compared to those who did not receive steroids (n = 161). The primary and secondary outcomes were 28- and 90-day mortality rates, respectively. Propensity scores were used to adjust for baseline covariates.

RESULTS

The overall mortality at 28 days was not significantly different between the corticosteroid-treated and control groups (43.8% vs. 41%, p = 0.541). At 90 days, the overall mortality rate was higher in the corticosteroid-treated group than in the control group (59.2% vs. 48.4%, p = 0.021). However, on propensity score matching, corticosteroid therapy was not associated with a higher 28-day mortality rate (odds ratio, 1.031; 95% confidence interval, 0.657 to 1.618; p = 0.895) and 90 days (odds ratio, 1.435; 95% confidence interval, 0.877 to 2.348; p = 0.151).

CONCLUSION

Corticosteroid therapy was not associated with 28- or 90-day mortality in the early phase of moderate to severe ARDS on propensity score matching analysis.

Management of ARDS - What Works and What Does Not

Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disorder associated with a variety of disease processes that lead to acute lung injury with increased non-hydrostatic extravascular lung water, reduced compliance, and severe hypoxemia. Despite significant advances, mortality associated with this syndrome remains high. Mechanical ventilation remains the most important aspect of managing patients with ARDS. An in-depth knowledge of lung protective ventilation, optimal PEEP strategies, modes of ventilation and recruitment maneuvers are essential for ventilatory management of ARDS. Although, the management of ARDS is constantly evolving as new studies are published and guidelines being updated; we present a detailed review of the literature including the most up-to-date studies and guidelines in the management of ARDS. We believe this review is particularly helpful in the current times where more than half of the acute care hospitals lack in-house intensivists and the burden of ARDS is at large.

Acute hypoxaemic respiratory failure in a low-income country: a prospective observational study of hospital prevalence and mortality

INTRODUCTION

Limited data exist on the epidemiology of acute hypoxaemic respiratory failure (AHRF) in low-income countries (LICs). We sought to determine the prevalence of AHRF in critically ill adult patients admitted to a Ugandan tertiary referral hospital; determine clinical and treatment characteristics as well as assess factors associated with mortality.

MATERIALS AND METHODS

We conducted a prospective observational study at the Mulago National Referral and Teaching Hospital in Uganda. Critically ill adults who were hospitalised at the emergency department and met the criteria for AHRF (acute shortness of breath for less than a week) were enrolled and followed up for 90 days. Multivariable analyses were conducted to determine the risk factors for death.

RESULTS

A total of 7300 patients was screened. Of these, 327 (4.5%) presented with AHRF. The majority (60 %) was male and the median age was 38 years (IQR 27-52). The mean plethysmographic oxygen saturation (SpO₂) was 77.6% (SD 12.7); mean SpO₂/FiO₂ ratio 194 (SD 32) and the mean Lung Injury Prediction Score (LIPS) 6.7 (SD 0.8). Pneumonia (80%) was the most common diagnosis. Only 6% of the patients received mechanical ventilatory support. In-hospital mortality was 77% with an average length of hospital stay of 9.2 days (SD 7). At 90 days after enrolment, the mortality increased to 85%. Factors associated with mortality were severity of hypoxaemia (risk ratio (RR) 1.29 (95% CI 1.15 to 1.54), p=0.01); a high LIPS (RR 1.79 (95% CI 1.79 1.14 to 2.83), p=0.01); thrombocytopenia (RR 1.23 (95% CI 1.11 to 1.38), p=0.01); anaemia (RR 1.15 (95% CI 1.01 to 1.31), p=0.03) ; HIV co-infection (RR 0.84 (95% CI 0.72 to 0.97), p=0.019) and male gender (RR 1.15 (95% CI 1.01 to 1.31) p=0.04).

CONCLUSIONS

The prevalence of AHRF among emergency department patients in a tertiary hospital in an LIC was low but was associated with very high mortality. Pneumonia was the most common cause of AHRF. Mortality was associated with higher severity of hypoxaemia, high LIPS, anaemia, HIV co-infection, thrombocytopenia and being male.

Targeting MALAT1 and miRNA-181a-5p for the intervention of acute lung injury/acute respiratory distress syndrome

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

This article has been retracted at the request of the authors due to a reported lack of agreement among the authors. The usage of the image in E-b part of Figure 7 had not received permission from the co-author. In order to resolve the issue, the authors agreed to retract the article.

Antifibrotics in COVID-19 Lung Disease: Let Us Stay Focused

After decades of research, two therapies for chronic fibrotic lung disease are now approved by the FDA, with dozens more anti-fibrotic therapies in the pipeline. A great deal of enthusiasm has been generated for the use of these drugs, which are by no means curative but clearly have a favorable impact on lung function decline over time. Amidst a flurry of newly developed and repurposed drugs to treat the coronavirus disease 2019 (COVID-19) and its accompanying acute respiratory distress syndrome (ARDS), few have emerged as effective. Historically, survivors of severe viral pneumonia and related acute lung injury with ARDS often have near full recovery of lung function. While the pathological findings of the lungs of patients with COVID-19 can be diverse, current reports have shown significant lung fibrosis predominantly in autopsy studies. There is growing enthusiasm to study anti-fibrotic therapy for inevitable lung fibrosis, and clinical trials are underway using currently FDA-approved anti-fibrotic therapies. Given the relatively favorable outcomes of survivors of virus-mediated ARDS and the low prevalence of clinically meaningful lung fibrosis in survivors, this perspective examines if there is a rationale for testing these repurposed antifibrotic agents in COVID-19-associated lung disease.

[Acute respiratory distress syndrome]

Das „acute respiratory distress syndrome“ (ARDS) ist ein intensivmedizinisches Syndrom, das bei gleichbleibend erhöhter Prävalenz weiterhin eine hohe Mortalität und Morbidität bedingt. Seit der initialen Beschreibung im Jahr 1968 sind inzwischen die Pathophysiologie mit Inflammation nach potenziellen Triggern, die Diagnostik zugrunde liegender Krankheitsentitäten, die Wertigkeit von differenzierter invasiver Beatmung und intensivmedizinischen Prozeduren und die Prognose deutlich besser erforscht und verstanden. Die Berliner ARDS-Definition aus dem Jahr 2012 mit dem Ziel der bettseitigen Identifikation von Patienten mit ARDS trägt diesen Tatsachen Rechnung. Vermeidung von invasiver Beatmung, wenn möglich, lungenprotektive Beatmung, wenn invasive Beatmung notwendig ist mit adäquatem PEEP (positiver endexspiratorischer Druck), und Reduktion von Baro- und Atelektrauma sowie Volumenmanagement und Lagerungstherapie bleiben die wichtigsten apparativen Therapien. Kausale Therapien sind weiterhin, abgesehen von der Behandlung zugrunde liegender Infektionen, nicht vorhanden. Für die Überlebenden eines ARDS ergeben sich sehr häufig relevante Langzeitfolgen.

Predictors for the development of preoperative oxygenation impairment in acute aortic dissection in hypertensive patients

BACKGROUND

Acute aortic dissection (AAD) is an acute life-threatening cardiovascular disease, which is frequently complicated with oxygenation impairment (OI). We aim to investigate predictors of the development of OI in the patients with AAD.

METHODS

We retrospectively collected clinical data of AAD in hypertensive patients from July 2012 to March 2020. The patients included in this study were divided into OI (+) group (oxygenation index≤200) and OI (-) group (oxygenation index> 200). Both groups were compared according to demographic and clinical characteristics, and laboratory findings. Characteristics of hypertension in the patients with AAD were described. Predictors for the development of OI were assessed. And cutoff values were determined by receiver operating characteristics (ROC) curve.

RESULTS

A total of 208 patients were included in this study and the incidence of OI was 32.2%. In OI (+) group, patients had significantly higher peak body temperature (37.85 ± 0.60 vs 37.64 ± 0.44 °C, P = .005), higher levels of CRP (42.70 ± 28.27 vs 13.90 ± 18.70 mg/L, P = .000) and procalcitonin (1.07 ± 3.92 vs 0.31 ± 0.77μg/L, P = .027), and lower levels of albumin (34.21 ± 5.65 vs 37.73 ± 4.70 g/L, P = .000). Spearman's rank correlation test showed that the minimum oxygenation index was positively correlated with albumin, and was negatively correlated with the peak body temperature, serum CRP, procalcitonin, BNP and troponin. The stepwise multiple linear regression analysis showed that the peak body temperature, serum CRP and albumin were independently associated with development of OI. An optimal cutoff value for CRP for predicting OI was ≥9.20 mg/L, with a sensitivity of 91.0% and a specificity of 61.0%.

CONCLUSIONS

The peak body temperature, serum CRP and albumin were independent predictors of OI development in the patients with AAD. The serum CRP on admission≥9.20 mg/L might be a valuable and reliable indicator in predicting the development of OI.

Potential role for furosemide in the treatment of acute respiratory distress syndrome (ARDS) and an unusual presentation of pulmonary embolism in a complex patient

An 81-year-old woman was admitted to our hospital after experiencing syncope. She was diagnosed with a large pulmonary embolism and was hemodynamically unstable therefore requiring endotracheal intubation and norepinephrine support. She presented with an upper gastrointestinal bleed which prevented her from receiving tissue plasminogen activator. She was treated with enoxaparin and ceftriaxone. Her blood, sputum and urine cultures were negative. When transferred to our ward, her antibiotic treatment was changed to piperacillin–tazobactam. A lumbar puncture was not suggestive of a central nervous system infection. Chest X-rays demonstrated rapid advancement of diffuse bilateral infiltrates which were not present at first and were interpreted by radiology consultation as suggestive of acute respiratory distress syndrome. An echocardiography showed right ventricle dilatation without left-sided heart failure. Diuretics were added and with this treatment, a quick respiratory improvement was noted as she regained consciousness and extubated shortly after.

The acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a prevalent cause of acute respiratory failure with high rates of mortality, as well as short- and long-term complications, such as physical and cognitive impairment. Therefore, early recognition of this syndrome and application of well-demonstrated therapeutic interventions are essential to change the natural course of this entity and bring about positive clinical outcomes. In this article, we review updated concepts in ARDS. Specifically, we discuss the current definition of ARDS, its risk factors, and the evidence supporting ventilation management, adjunctive therapies, and interventions required in refractory hypoxemia.

Spiraea prunifolia var. simpliciflora Attenuates Oxidative Stress and Inflammatory Responses in a Murine Model of Lipopolysaccharide-Induced Acute Lung Injury and TNF-α-Stimulated NCI-H292 Cells

Spiraea prunifolia var. simpliciflora (SP) is traditionally used as an herbal remedy to treat fever, malaria, and emesis. This study aimed to evaluate the anti-oxidative and anti-inflammatory properties of the methanol extract of SP leaves in tumor necrosis factor (TNF)-α-stimulated NCI-H292 cells and in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. SP decreased the number of inflammatory cells and the levels of TNF-α, interleukin (IL)-1β, and IL-6 in the bronchoalveolar lavage fluid, and inflammatory cell infiltration in the lung tissues of SP-treated mice. In addition, SP significantly suppressed the mRNA and protein levels of TNF-α, IL-1β, and IL-6 in TNF-α-stimulated NCI-H292 cells. SP significantly suppressed the phosphorylation of the mitogen-activated protein kinases (MAPKs) and p65-nuclear factor-kappa B (NF-κB) in LPS-induced ALI mice and TNF-α-stimulated NCI-H292 cells. SP treatment enhanced the nuclear translocation of nuclear factor erythroid 2-related factor (Nrf2) with upregulated antioxidant enzymes and suppressed reactive oxygen species (ROS)-mediated oxidative stress in the lung tissues of LPS-induced ALI model and TNF-α-stimulated NCI-H292 cells. Collectively, SP effectively inhibited airway inflammation and ROS-mediated oxidative stress, which was closely related to its ability to induce activation of Nrf2 and inhibit the phosphorylation of MAPKs and NF-κB. These findings suggest that SP has therapeutic potential for the treatment of ALI.

An NMR based panorama of the heterogeneous biology of acute respiratory distress syndrome (ARDS) from the standpoint of metabolic biomarkers

Acute respiratory distress syndrome (ARDS), manifested by intricate etiology and pathophysiology, demands careful clinical surveillance due to its high mortality and imminent life support measures. NMR based metabolomics provides an approach for ARDS which culminates from a wide spectrum of illness thereby confounding early manifestation and prognosis predictors. ¹ H NMR with its manifold applications in critical disease settings can unravel the biomarker of ARDS thus holding potent implications by providing surrogate endpoints of clinical utility. NMR metabolomics which is the current apogee platform of omics trilogy is contributing towards the possible panacea of ARDS by subsequent validation of biomarker credential on larger datasets. In the present review, the physiological derangements that jeopardize the whole metabolic functioning in ARDS are exploited and the biomarkers involved in progression are addressed and substantiated. The following sections of the review also outline the clinical spectrum of ARDS from the standpoint of NMR based metabolomics which is an emerging element of systems biology. ARDS is the main premise of intensivists textbook, which has been thoroughly reviewed along with its incidence, progressive stages of severity, new proposed diagnostic definition, and the preventive measures and the current pitfalls of clinical management. The advent of new therapies, the need for biomarkers, the methodology and the contemporary promising approaches needed to improve survival and address heterogeneity have also been evaluated. The review has been stepwise illustrated with potent biometrics employed to selectively pool out differential metabolites as diagnostic markers and outcome predictors. The following sections have been drafted with an objective to better understand ARDS mechanisms with predictive and precise biomarkers detected so far on the basis of underlying physiological parameters having close proximity to diseased phenotype. The aim of this review is to stimulate interest in conducting more studies to help resolve the complex heterogeneity of ARDS with biomarkers of clinical utility and relevance.

Neuromuscular blockade in acute respiratory distress syndrome: a systematic review and meta-analysis of randomized controlled trials

Background

Neuromuscular blocking agent (NMBA) has been proposed by medical guidelines for early severe acute respiratory distress syndrome (ARDS) because of its survival benefits. However, new studies have provided evidence contradicting these results.

Method

A search was performed of the Pubmed, Scopus, Clinicaltrials.gov, and Virtual Health Library databases for randomized controlled trials (RCT) evaluating 28-day mortality in ARDS patients treated with NMBA within 48 h. An English language restriction was applied. Relevant data were extracted and pooled into risk ratios (RR), mean differences (MD), and corresponding 95% confidence intervals (CI) using random-effect model. Sensitivity and meta-regression analysis were performed.

Results

From 2675 studies, we included five RCTs in the analysis, for a total of 1461 patients with a mean PaO₂/FIO₂ of 104 ± 35 mmHg. The cisatracurium group had the same risk of death at 28 days (RR, 0.90; 95% CI, 0.78–1.03; I² = 50%, p = 0.12) and 90 days (RR, 0.81; 95% CI, 0.62–1.06; I² = 56%, p = 0.06) as the control group (no cisatracurium). The secondary outcomes of mechanical ventilation duration and ventilator-free days were not different between the two groups. Cisatracurium had a significantly lower risk of barotrauma than the control group with no difference in intensive care unit (ICU)–induced weakness. The PaO₂/FIO₂ ratio was higher in the cisatracurium group but not until 48 h. Meta-regression analysis of the baseline PaO₂/FIO₂ ratio, positive end-expiratory pressure (PEEP) revealed no heterogeneity. Subgroup analysis excluding the trial using high PEEP and light sedation strategy yielded an improvement in all mortality outcomes.

Conclusion

NMBA improves oxygenation only after 48 h in moderate, severe ARDS patients and has a lower barotrauma risk without affecting ICU weakness. However, NMBA does not reduce ventilator-free days, duration of mechanical ventilation or, most importantly, the mortality risk regardless of the severity of ARDS.

Acute Respiratory Distress Syndrome immediately following the removal of an aspirated foreign body

Acute Respiratory Distress Syndrome (ARDS) is a form of diffuse lung injury with many potential etiologies, pneumonia being the most common cause developing outside of the hospital. Foreign body (FB) aspiration is a risk factor for pneumonia, and therefore, ARDS. Although these associations exist, the development of ARDS immediately following the removal of an aspirated FB appears quite rare.

We present the case of an 11 year old male who was found to have a right-sided, post-obstructive pneumonia secondary to an aspirated FB obstructing the bronchus intermedius. Relief of the obstruction allowed for rapid, endobronchial spread of infection and within 6 hours of FB removal, our patient developed severe ARDS requiring initiation of extracorporeal membrane oxygenation (ECMO). Streptococcus constellatus was isolated from lower respiratory cultures obtained during initial bronchoscopy.

Acute Respiratory Distress Syndrome Definition, Causes, and Pathophysiology

First successfully described in 1967, acute respiratory distress syndrome has since garnered much interest and debate. Extensive studies and clinical trials have been carried out in efforts to address the associated high mortality; however, it remains a significant burden on health care. Despite the heterogeneous etiologies that lead to the development of acute respiratory distress syndrome, this rapidly progressing form of respiratory failure, characterized by severe hypoxemia and nonhydrostatic pulmonary edema, has a recognizable pattern of lung injury. In this chapter, we will review the clinical manifestations, definitions, causes, and a brief overview of the pathophysiology of this complex syndrome.

Preoperative hypoxemia in patients with type A acute aortic dissection: a retrospective study on incidence, related factors and clinical significance

Background

Pre-operative hypoxemia (HO) is a serious complication occurring in acute type A aortic dissection (AAD) patients.

Methods

This was a retrospective study of 505 patients who underwent Stanford type A acute aortic dissection surgery in Anzhen hospital, Beijing, China, between January 2015 to February 2018. Patients were divided into a HO(+) group (PaO₂/FiO₂ ≤300) and a HO(-) group (PaO₂/FiO₂ >300) according to preoperative arterial blood gas (ABG) analysis. The incidence of preoperative hypoxemia in patients undergoing surgery for AAD was calculated as the main outcome. Multivariable binary logistic regression analysis was used to identify independent prognostic factors of HO.

Results

Preoperative HO occurred in 46.5% (235/505) of patients. Mean patient age was 47.8±9.6 years, and 189 (80.4%) were male. Multivariable logistic regression analysis showed a correlation between preoperative serum level of fibrinogen [95% confidence interval (CI), 0.95-0.99], white blood cell count (WBC) (95% CI, 1.07-1.18), systolic blood pressure (95% CI, 0.98-1.00), history of smoking (95% CI, 1.05-2.11) and pleural effusion (95% CI, 1.14-2.71) with preoperative HO. The HO(+) group had a significantly higher mortality than the HO(-) group (8.1% vs. 5.9%, P=0.38). The median of intubation time (P<0.01), the length of stay in the intensive care unit (P<0.01) and the length of hospital stay (P<0.01) were significantly longer in patients with HO. The activity of daily living scale score was significantly lower in the HO(+) group (P<0.01).

Conclusions

AAD patients were easy to have pre-operative HO, which had a higher morbidity than those without HO. Altered fibrinogen, WBC, systolic blood pressure levels, positive smoking history, and pleural effusion were associated with the presence of HO. More monitoring and treatment should be given to these patients.

Blocking of gastric acid induced histopathological alterations, enhancing of DNA content and proliferation of goblet cells in the acute lung injury mice models by nano-fenugreek oral administration

This current study aimed at detecting the potential protective role of nano-fenugreek seed on acute lung injury (ALI) induced by instillation gastric acid in male Swiss albino mice using histological and histochemical studies. Forty animals were grouped as follows: control group, HCl-treated group, low nano-fenugreek + HCl treated group, and high nano-fenugreek + HCl treated group. Pretreatment with nano-fenugreek in animal model of ALI resulted in marked ameliorations of the lung histological lesions and injury induced by HCL instillation in a dose dependent manner. It also caused inhibition in the increase of the DNA content and prevented proliferation of goblet cells induced by HCl instillation alone. In conclusion, pretreatment with Nano-fenugreek prior induction ALI could be suppress the aggregations of inflammatory cells, enhancing of DNA content, and proliferation of goblet cells induced by gastric acid in a dose dependent manner. We suggest that Nano-fenugreek may be useful in combating lung injury.

IKKβ regulates the expression of coagulation and fibrinolysis factors through the NF-κB canonical pathway in LPS-stimulated alveolar epithelial cells type II

Aim: Hypercoagulation and fibrinolysis inhibition in the alveolar cavity are important characteristics in acute respiratory distress syndrome (ARDS). Alveolar epithelial cells type II (AEC II) have been confirmed to have significant role in regulating alveolar hypercoagulation and fibrinolysis inhibition, but the mechanism is unknown. Nuclear factor-κB (NF-κB) signaling pathway has been demonstrated to participate in the pathogenesis of these two abnormalities in ARDS. The purpose of the present study is to explore whether controlling the upstream crucial factor IκB kinase (IKK)β could regulate coagulation and fibrinolysis factors in LPS-stimulated AEC II. Materials and methods: An IKKβ gene regulation model (IKKβ^+/+ and IKKβ^−/−) was prepared using lentiviral vector transfection. The models with wild type cells were all stimulated by lipopolysaccharide (LPS) or saline for 24 h. Expression of the related proteins were determined by western-blotting, ELISA and revere transcription-PCR respectively. Tissue factor (TF) procoagulant activity and nuclear p65 protein level were also detected. Results: IKKβ increased in IKKβ^+/+ cells but decreased in IKKβ^−/− cells. LPS stimulation promoted the expression of p-IκBα, p65, p-p65 and p-IKKβ as well as TF and plasminogen activator inhibitor (PAI)-1, at the mRNA or protein level, and this was significantly enhanced by IKKβ upregulation but weakened by IKKβ downregulation. TF procoagulant activity presented the same changes as the molecules above. ELISAs showed additional increases in the concentrations of as thrombin antithrombin, procollagen III propeptide, thrombomodulin and PAI-1 in IKKβ^+/+ cell supernatant under LPS stimulation, however they decreased in IKKβ^−/−. The level of as antithrombin III however, appeared to show the opposite change to those other factors. Immunofluorescence demonstrated a greatly enhanced expression of p65 in the nucleus by IKKβ upregulation, which was reduced by IKKβ downregulation. Conclusions: IKKβ could regulate the expression and secretion of coagulation and fibrinolysis factors in LPS-stimulated AEC II via the NF-κB p65 signaling pathway. The IKKβ molecule is expected to be a new target for prevention of coagulation and fibrinolysis abnormalities in ARDS.

Incidence and risk factors of pulmonary atelectasis in mechanically ventilated trauma patients in ICU: a prospective study

AIM

The aim of the study was to obtain information about the incidence and risk factors for pulmonary atelectasis in mechanically ventilated patients in the trauma ICU (TMICU). Pulmonary atelectasis is a common complication leading to serious lung dysfunction in patients in the TMICU and early identification of patients at risk is important for their effective management.

METHODS

All trauma patients admitted to the TMICU with mechanical ventilation for more than 1 day were included in a prospective 12-month study. Pulmonary atelectasis was diagnosed from chest radiographs by a critical care doctor and radiologist.

RESULTS

A total of 405 trauma patients were identified and data from 338 patients analyzed showing the incidence of pulmonary atelectasis to be 14%. Multivariate analysis revealed significant risk factors to be chest injury with an adjusted odds ratio (AOR) of 102.8, abdominal injury (AOR: 4.6), surgical intervention (AOR: 8.4), comorbidity (AOR: 13.7), Acute Physiology and Chronic Health Evaluation II score (APACHE II) of at least 15 (AOR: 4.8), sedation of at least 7 days (AOR: 7.5) and mechanical ventilation of at least 9 days (AOR: 3.43). Patients with chronic pulmonary disease tended to have higher risk for pulmonary atelectasis (AOR: 8.8). Patients with pulmonary atelectasis had longer stays in TMICU (P < 0.001) and higher mortality (P = 0.013).

CONCLUSION

The incidence of pulmonary atelectasis in TMICU in Thailand is comparable with that of the developed world. Pulmonary atelectasis is particularly associated with chest trauma, whereas abdominal injury, APACHE II of at least 15, surgery, comorbidity and prolonged mechanical ventilation are also significant risk factors. Early interventions to prevent or treat pulmonary atelectasis in these patients may improve outcome and shorten their stay in the TMICU and hospital.