Causes and characteristics of death in patients with acute hypoxemic respiratory failure and acute respiratory distress syndrome: a retrospective cohort study

Shenfu injection targets the PI3K-AKT pathway to regulate autophagy and apoptosis in acute respiratory distress syndrome caused by sepsis

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by an exaggerated response to infection. In the lungs, one of the most susceptible organs, this can manifest as acute respiratory distress syndrome (ARDS). Shenfu (SF) injection is a prominent traditional Chinese medicine used to treat sepsis. However, the exact mechanism of its action has rarely been reported in the literature.

PURPOSE

In the present study, we detected the protective effect of SF injection on sepsis-induced ARDS and explored its underlying mechanism.

METHODS

We investigated the potential targets and regulatory mechanisms of SF injections using a combination of network pharmacology and RNA sequencing. This study was conducted both in vivo and in vitro using a mouse model of ARDS and lipopolysaccharide (LPS)-stimulated MLE-12 cells, respectively.

RESULTS

The results showed that SF injection could effectively inhibit inflammation, oxidative stress, and apoptosis to alleviate LPS-induced ARDS. SF inhibited the PI3K-AKT pathway, which controls autophagy and apoptosis. Subsequently, MLE-12 cells were treated with 3-methyladenine to assess its effects on autophagy and apoptosis. Additional experiments were conducted by adding rapamycin, an mTOR antagonist, or SC79, an AKT agonist, to investigate the effects of SF injection on autophagy, apoptosis, and the PI3K-AKT pathway.

CONCLUSION

Overall, we found that SF administration could enhance autophagic activity, reduce apoptosis, suppress inflammatory responses and oxidative stress, and inhibit the PI3K-AKT pathway, thus ameliorating sepsis-induced ARDS.

Evaluation of interleukin-1 and interleukin-6 receptor antagonists in a murine model of acute lung injury

The acute exudative phase of acute respiratory distress syndrome (ARDS), a severe form of respiratory failure, is characterized by alveolar damage, pulmonary oedema, and an exacerbated inflammatory response. There is no effective treatment for this condition, but based on the major contribution of inflammation, anti-inflammatory strategies have been evaluated in animal models and clinical trials, with conflicting results. In COVID-19 ARDS patients, interleukin (IL)-1 and IL-6 receptor antagonists (IL-1Ra and IL-6Ra, kineret and tocilizumab, respectively) have shown some efficacy. Moreover, we have previously developed novel peptides modulating IL-1R and IL-6R activity (rytvela and HSJ633, respectively) while preserving immune vigilance and cytoprotective pathways. We aimed to assess the efficacy of these novel IL-1Ra and IL-6Ra, compared to commercially available drugs (kineret, tocilizumab) during the exudative phase (day 7) of bleomycin-induced acute lung injury (ALI) in mice. Our results first showed that none of the IL-1Ra and IL-6Ra compounds attenuated bleomycin-induced weight loss and venousP C O 2 ${P_{{\mathrm{C}}{{\mathrm{O}}_{\mathrm{2}}}}}$ increase. Histological analyses and lung water content measurements also showed that these drugs did not improve lung injury scores or pulmonary oedema, after the bleomycin challenge. Finally, IL-1Ra and IL-6Ra failed to alleviate the inflammatory status of the mice, as indicated by cytokine levels and alveolar neutrophil infiltration. Altogether, these results indicate a lack of beneficial effects of IL-1R and IL-6R antagonists on key parameters of ALI in the bleomycin mouse model.

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

BACKGROUND

Hypoinflammatory and hyperinflammatory phenotypes have been identified in both Acute Respiratory Distress Syndrome (ARDS) and sepsis. Attributable mortality of ARDS in each phenotype of sepsis is yet to be determined. We aimed to estimate the population attributable fraction of death from ARDS (PAFARDS) in hypoinflammatory and hyperinflammatory sepsis, and to determine the primary cause of death within each phenotype.

METHODS

We studied 1737 patients with sepsis from two prospective cohorts. Patients were previously assigned to the hyperinflammatory or hypoinflammatory phenotype using latent class analysis. The PAFARDS in patients with sepsis was estimated separately in the hypo and hyperinflammatory phenotypes. Organ dysfunction, severe comorbidities, and withdrawal of life support were abstracted from the medical record in a subset of patients from the EARLI cohort who died (n = 130/179). Primary cause of death was defined as the organ system that most directly contributed to death or withdrawal of life support.

RESULTS

The PAFARDS was 19% (95%CI 10,28%) in hypoinflammatory sepsis and, 14% (95%CI 6,20%) in hyperinflammatory sepsis. Cause of death differed between the two phenotypes (p < 0.001). Respiratory failure was the most common cause of death in hypoinflammatory sepsis, whereas circulatory shock was the most common cause in hyperinflammatory sepsis. Death with severe underlying comorbidities was more frequent in hypoinflammatory sepsis (81% vs. 67%, p = 0.004).

CONCLUSIONS

The PAFARDS is modest in both phenotypes whereas primary cause of death among patients with sepsis differed substantially by phenotype. This study identifies challenges in powering future clinical trials to detect changes in mortality outcomes among patients with sepsis and ARDS.

MORTALITY AND ASSOCIATED FACTORS AMONG INTENSIVE CARE UNIT ADMITTED ADULT PATIENTS WITH MECHANICAL VENTILATION IN ETHIOPIA: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT

Introduction: The global demand for intensive care has risen, given its effectiveness in lowering mortality rates. Mechanical ventilation (MV) is integral to intensive care but introduces risks such as ventilator-associated complications. Ethiopia experiences a high intensive care unit (ICU) mortality rate. Objective: This systematic review and meta-analysis aim to comprehensively synthesize evidence on the mortality of adults undergoing MV in Ethiopia and identify associated factors. Methods: The study extensively searched databases and gray literature for research on MV outcomes, trends, and associated factors in adult ICUs. Adhering to the 2020 PRISMA checklist, a systematic review and meta-analysis sought to establish the mortality rate and key determinants among adult ICU patients on MV. The search incorporated keywords and MeSH terms, excluding studies with unsound methodologies or missing data. Data extraction, quality assessment, and analysis followed established protocols, including the JBI tool for methodological quality evaluation. STATA version 17.0 facilitated analysis, assessing heterogeneity, publication bias, and performing sensitivity and meta-regression analyses. Results: The pooled mortality rate among adult ICU patients undergoing MV was 48.61% (95% CI: 40.82, 56.40%). Significant mortality-contributing factors included medical diagnosis, Glasgow Coma Scale score, sepsis/septic shock, sedation use, multiple-organ dysfunction syndrome, and cardiovascular disease. Although some pooled odds ratios seemed insignificant, closer examination revealed significant associations in individual studies. Conclusion : The study underscores the urgent need for further research, improved ICU infrastructure, and healthcare personnel training in Ethiopia to enhance outcomes for mechanically ventilated patients. Identified factors offer valuable insights for targeted interventions, guiding tailored treatment strategies to reduce mortality. This study contributes to understanding mortality and associated factors in MV patients, informing initiatives to improve critical care outcomes in Ethiopia.

Kinetics of C-reactive protein during extracorporeal membrane oxygenation

BACKGROUND

The exposure of blood to the artificial circuit during extracorporeal membrane oxygenation (ECMO) can induce an inflammatory response. C-reactive protein (CRP) is a commonly used biomarker of systemic inflammation.

METHODS

In this retrospective observational study, we analyzed results of daily plasma CRP measurements in 110 critically ill patients, treated with ECMO. We compared CRP levels during the first 5 days of ECMO operation, between different groups of patients according to ECMO configurations, Coronavirus disease 2019 (COVID-19) status, and mechanical ventilation parameters.

RESULTS

There was a statistically significant decrease in CRP levels during the first 5 days of veno-venous (VV) ECMO (173 ± 111 mg/L, 154 ± 107 mg/L, 127 ± 97 mg/L, 114 ± 100 mg/L and 118 ± 90 mg/L for days 1-5 respectively, p < 0.001). Simultaneously, there was a significant reduction in ventilatory parameters, as represented by the mechanical power (MP) calculation, from 24.02 ± 14.53 J/min to 6.18 ± 4.22 J/min within 3 h of VV ECMO initiation (p < 0.001). There was non-significant trend of increase in CRP level during the first 5 days of veno arterial (VA) ECMO (123 ± 80 mg/L, 179 ± 91 mg/L, 203 ± 90 mg/L, 179 ± 95 mg/L and 198 ± 93 for days 1-5 respectively, p = 0.126) and no significant change in calculated MP (from 14.28 ± 8.56 J/min to 10.81 ± 8.09 J/min within 3 h if ECMO initiation, p = 0.071).

CONCLUSIONS

We observed a significant decrease in CRP levels during the first 5 days of VV ECMO support, and suggest that the concomitant reduction in ventilatory MP may have mitigated the degree of alveolar stress and strain that could have contributed to a decrease in the systemic inflammatory process.

COAGULOPATHY PARAMETERS PREDICTIVE OF OUTCOMES IN SEPSIS-INDUCED ACUTE RESPIRATORY DISTRESS SYNDROME: A SUBANALYSIS OF THE TWO PROSPECTIVE MULTICENTER COHORT STUDIES

ABSTRACT

Background: Although coagulopathy is often observed in acute respiratory distress syndrome (ARDS), its clinical impact remains poorly understood. Objectives: This study aimed to clarify the coagulopathy parameters that are clinically applicable for prognostication and to determine anticoagulant indications in sepsis-induced ARDS. Method: This study enrolled patients with sepsis-derived ARDS from two nationwide multicenter, prospective observational studies. We explored coagulopathy parameters that could predict outcomes in the Focused Outcome Research on Emergency Care for Acute Respiratory Distress Syndrome, Sepsis, and Trauma (FORECAST) cohort, and the defined coagulopathy criteria were validated in the Sepsis Prognostication in Intensive Care Unit and Emergency Room-Intensive Care Unit (SPICE-ICU) cohort. The correlation between anticoagulant use and outcomes was also evaluated. Results: A total of 181 patients with sepsis-derived ARDS in the FORECAST study and 61 patients in the SPICE-ICU study were included. In a preliminary study, we found the set of prothrombin time-international normalized ratio ≥1.4 and platelet count ≤12 × 10 4 /μL, and thrombocytopenia and elongated prothrombin time (TEP) coagulopathy as the best coagulopathy parameters and used it for further analysis; the odds ratio (OR) of TEP coagulopathy for in-hospital mortality adjusted for confounding was 3.84 (95% confidence interval [CI], 1.66-8.87; P = 0.005). In the validation cohort, the adjusted OR for in-hospital mortality was 32.99 (95% CI, 2.60-418.72; P = 0.002). Although patients without TEP coagulopathy showed significant improvements in oxygenation over the first 4 days, patients with TEP coagulopathy showed no significant improvement (ΔPaO 2 /FiO 2 ratio, 24 ± 20 vs. 90 ± 9; P = 0.026). Furthermore, anticoagulant use was significantly correlated with mortality and oxygenation recovery in patients with TEP coagulopathy but not in patients without TEP coagulopathy. Conclusion: Thrombocytopenia and elongated prothrombin time coagulopathy is closely associated with better outcomes and responses to anticoagulant therapy in sepsis-induced ARDS, and our coagulopathy criteria may be clinically useful.

A scoring model based on clinical factors to predict postoperative moderate to severe acute respiratory distress syndrome in Stanford type A aortic dissection

BACKGROUND

Postoperative acute respiratory distress syndrome (ARDS) after type A aortic dissection is common and has high mortality. However, it is not clear which patients are at high risk of ARDS and an early prediction model is deficient.

METHODS

From May 2015 to December 2017, 594 acute Stanford type A aortic dissection (ATAAD) patients who underwent aortic surgery in Anzhen Hospital were enrolled in our study. We compared the early survival of MS-ARDS within 24 h by Kaplan-Meier curves and log-rank tests. The data were divided into a training set and a test set at a ratio of 7:3. We established two prediction models and tested their efficiency.

RESULTS

The oxygenation index decreased significantly immediately and 24 h after TAAD surgery. A total of 363 patients (61.1%) suffered from moderate and severe hypoxemia within 4 h, and 243 patients (40.9%) suffered from MS-ARDS within 24 h after surgery. Patients with MS-ARDS had higher 30-day mortality than others (log-rank test: p-value <0.001). There were 30 variables associated with MS-ARDS after surgery. The XGboost model consisted of 30 variables. The logistic regression model (LRM) consisted of 11 variables. The mean accuracy of the XGBoost model was 70.7%, and that of the LRM was 80.0%. The AUCs of XGBoost and LRM were 0.764 and 0.797, respectively.

CONCLUSION

Postoperative MS-ARDS significantly increased early mortality after TAAD surgery. The LRM model has higher accuracy, and the XGBoost model has higher specificity.

Acute respiratory failure-related excess mortality in pediatric sepsis

Excess mortality risk imparted by acute respiratory failure in children is unknown. We determined excess mortality risk associated with mechanically ventilated acute respiratory failure in pediatric sepsis. Novel ICD10-based algorithms were derived and validated to identify a surrogate for acute respiratory distress syndrome to calculate excess mortality risk. Algorithm-identified ARDS was identified with specificity of 96.7% (CI 93.0 - 98.9) and sensitivity of 70.5% (CI 44.0 - 89.7). Excess risk of mortality for ARDS was 24.4% (CI 22.9 - 26.2). Development of ARDS requiring mechanical ventilation imparts modest excess risk of mortality in septic children.

Effects of adding the second drainage cannula in severely hypoxemic patients supported with VV ECMO due to COVID-19-associated ARDS

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a recognized method of support in patients with severe and refractory acute respiratory distress syndrome (ARDS) caused by SARS-CoV-2 infection. While veno-venous (VV) ECMO is the most common type, some patients with severe hypoxemia may require modifications to the ECMO circuit. In this study, we aimed to investigate the effects of adding a second drainage cannula to the circuit in patients with refractory hypoxemia, on their gas exchange, mechanical ventilation, ECMO settings, and clinical outcomes.

METHODS

We conducted an observational retrospective study based on a single-center institutional registry including all consecutive cases of COVID-19 patients requiring ECMO admitted to the Centre of Extracorporeal Therapies in Warsaw between March 1, 2020 and March 1, 2022. We selected patients who had an additional drainage cannula inserted. Changes in ECMO and ventilator settings, blood oxygenation, and hemodynamic parameters, as well as clinical outcomes were assessed.

RESULTS

Of 138 VV ECMO patients, 12 (9%) patients met the inclusion criteria. Ten patients (83%) were men, and mean age was 42.2 ± 6.8. An addition of drainage cannula resulted in a significant raise in ECMO blood flow (4.77 ± 0.44 to 5.94 ± 0.81 [L/min]; p = 0.001), and the ratio of ECMO blood flow to ECMO pump rotations per minute (RPM), whereas the raise in ECMO RPM alone was not statistically significant (3432 ± 258 to 3673 ± 340 [1/min]; p = 0.064). We observed a significant drop in ventilator FiO2 and a raise in PaO2 to FiO2 ratio, while blood lactates did not change significantly. Nine patients died in hospital, one was referred to lung transplantation center, two were discharged uneventfully.

CONCLUSIONS

The use of an additional drainage cannula in severe ARDS associated with COVID-19 allows for an increased ECMO blood flow and improved oxygenation. However, we observed no further improvement in lung-protective ventilation and poor survival.

Sepsis and acute respiratory failure in patients with cancer: how can we improve care and outcomes even further?

PURPOSE OF REVIEW

Care and outcomes of critically ill patients with cancer have improved over the past decade. This selective review will discuss recent updates in sepsis and acute respiratory failure among patients with cancer, with particular focus on important opportunities to improve outcomes further through attention to phenotyping, predictive analytics, and improved outcome measures.

RECENT FINDINGS

The prevalence of cancer diagnoses in intensive care units (ICUs) is nontrivial and increasing. Sepsis and acute respiratory failure remain the most common critical illness syndromes affecting these patients, although other complications are also frequent. Recent research in oncologic sepsis has described outcome variation - including ICU, hospital, and 28-day mortality - across different types of cancer (e.g., solid vs. hematologic malignancies) and different sepsis definitions (e.g., Sepsis-3 vs. prior definitions). Research in acute respiratory failure in oncology patients has highlighted continued uncertainty in the value of diagnostic bronchoscopy for some patients and in the optimal respiratory support strategy. For both of these syndromes, specific challenges include multifactorial heterogeneity (e.g. in etiology and/or underlying cancer), delayed recognition of clinical deterioration, and complex outcomes measurement.

SUMMARY

Improving outcomes in oncologic critical care requires attention to the heterogeneity of cancer diagnoses, timely recognition and management of critical illness, and defining appropriate ICU outcomes.

Risk factors for mortality in patients with acute exacerbation of cor pulmonale in plateau

BACKGROUND

The risk factors for mortality might differ between patients with acute exacerbation of chronic pulmonary heart disease in plains and plateaus, while there is a lack of evidence.

METHOD

Patients diagnosed with cor pulmonale at Qinghai Provincial People's Hospital were retrospectively included between January 2012 and December 2021. The symptoms, physical and laboratory examination findings, and treatments were collected. Based on the survival within 50 days, we divided the patients into survival and death groups.

RESULTS

After 1:10 matching according to gender, age, and altitude, 673 patients were included in the study, 69 of whom died. The multivariable Cox proportional hazards analysis showed that NYHA class IV (HR = 2.03, 95%CI: 1.21-3.40, P = 0.007), type II respiratory failure (HR = 3.57, 95%CI: 1.60-7.99, P = 0.002), acid-base imbalance (HR = 1.82, 95%CI: 1.06-3.14, P = 0.031), C-reactive protein (HR = 1.04, 95%CI: 1.01-1.08, P = 0.026), and D-dimer (HR = 1.07, 95%CI: 1.01-1.13, P = 0.014) were risk factors for death in patients with cor pulmonale at high altitude. Among patients living below 2500 m, cardiac injury was a risk factor for death (HR = 2.47, 95%CI: 1.28-4.77, P = 0.007), while no significant association was observed at ≥ 2500 m (P = 0.057). On the contrary, the increase of D-dimer was only a risk factor for the death of patients living 2500 m and above (HR = 1.23, 95% CI: 1.07-1.40, P = 0.003).

CONCLUSION

NYHA class IV, type II respiratory failure, acid-base imbalance, and C- reactive protein may increase the risk of death in patients with cor pulmonale. Altitude modified the association between cardiac injury, D-dimer, and death in patients with cor pulmonale.

Causes of Death Among Medical ICU Patients With Pneumonia Due to COVID-19 in a Safety-Net Hospital

We sought to identify the primary causes of death of adult patients admitted to the medical ICU with symptomatic COVID-19 who ultimately suffered in-hospital mortality over the span of three major waves of COVID-19: Wild-type, alpha/epsilon, and delta.

DESIGN

Retrospective single-center cohort study from March 2020 to December 2021.

SETTING

One medical ICU in a 600-bed Tertiary Care Hospital in Los Angeles, CA.

PATIENTS

Adult (n = 306) ICU patients admitted with symptomatic COVID-19 who suffered in-hospital mortality.

INTERVENTIONS

None.

MAIN RESULTS

Of the 306 patients with COVID-19 who died in the hospital, 86.3% were Hispanic/Latino. The leading cause of death was respiratory failure, occurring in 57.8% of patients. There was no significant change in the rate of pulmonary deaths across the three waves of COVID-19 in our study period. The mean time from symptom onset to admission was 6.5 days, with an average hospital length of stay of 18 days. This did not differ between pulmonary and other causes of death. Sepsis was the second most common cause of death at 23.9% with a significant decrease from the wild-type wave to the delta wave. Among patients with sepsis as the cause of death, 22% (n = 16) were associated with fungemia. There was no significant association between steroid administration and cause of death. Lastly, the alpha/epsilon wave from December 2020 to May 2021 had the highest mortality rate when compared with wild-type or delta waves.

CONCLUSIONS

We found the primary cause of death in ICU patients with COVID-19 was acute respiratory failure, without significant changes over the span of three waves of COVID-19. This finding contrasts with reported causes of death for patients with non-COVID-19 acute respiratory distress syndrome, in which respiratory failure is an uncommon cause of death. In addition, we identified a subset of patients (5%) who died primarily due to fungemia, providing an area for further investigation.

Biomarker Signatures of Severe Acute Kidney Injury in a Critically Ill Cohort of COVID-19 and Non-COVID-19 Acute Respiratory Illness

Kidney and lung injury are closely inter-related during acute respiratory illness, but the molecular risk factors that these organ injuries share are not well defined.

OBJECTIVES

We identified plasma biomarkers associated with severe acute kidney injury (AKI) during acute respiratory illness, and compared them to biomarkers associated with severe acute respiratory failure (ARF).

DESIGN SETTINGS AND PARTICIPANTS

Prospective observational cohort study enrolling March 2020 through May 2021, at three hospitals in a large academic health system. We analyzed 301 patients admitted to an ICU with acute respiratory illness.

MAIN OUTCOMES AND MEASURES

Outcomes were ascertained between ICU admission and day 14, and included: 1) severe AKI, defined as doubling of serum creatinine or new dialysis and 2) severe ARF, which included new or persistent need for high-flow oxygen or mechanical ventilation. We measured biomarkers of immune response and endothelial function, pathways related to adverse kidney and lung outcomes, in plasma collected within 24 hours of ICU admission. Severe AKI occurred in 48 (16%), severe ARF occurred in 147 (49%), and 40 (13%) patients experienced both. Two-fold higher concentrations of soluble tumor necrosis factor receptor-1 (sTNFR-1) (adjusted relative risk [aRR], 1.56; 95% CI, 1.24-1.96) and soluble triggering receptor on myeloid cells-1 (sTREM-1) (aRR, 1.85; 95% CI, 1.42-2.41), biomarkers of innate immune activation, were associated with higher risk for severe AKI after adjustment for age, sex, COVID-19, and Acute Physiology and Chronic Health Evaluation-III. These biomarkers were not significantly associated with severe ARF. Soluble programmed cell death receptor-1 (sPDL-1), a checkpoint pathway molecule, as well as soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular adhesion molecule-1 (sVCAM-1), molecules involved with endothelial-vascular leukocyte adhesion, were associated with both severe AKI and ARF.

CONCLUSIONS AND RELEVANCE

sTNFR-1 and sTREM-1 were linked strongly to severe AKI during respiratory illness, while sPDL-1, sICAM-1 and sVCAM-1 were associated with both severe AKI and ARF. These biomarker signatures may shed light on pathophysiology of lung-kidney interactions, and inform precision medicine strategies for identifying patients at high risk for these organ injuries.

Radiologic Assessment of Lung Edema Score as a Predictor of Clinical Outcome in Children with Acute Respiratory Distress Syndrome

PURPOSE

The radiographic assessment of lung edema (RALE) score enables objective quantification of lung edema and is a valuable prognostic marker of adult acute respiratory distress syndrome (ARDS). We aimed to evaluate the validity of RALE score in children with ARDS.

MATERIALS AND METHODS

The RALE score was measured for its reliability and correlation to other ARDS severity indices. ARDS-specific mortality was defined as death from severe pulmonary dysfunction or the need for extracorporeal membrane oxygenation therapy. The C-index of the RALE score and other ARDS severity indices were compared via survival analyses.

RESULTS

Among 296 children with ARDS, 88 did not survive, and there were 70 ARDS-specific non-survivors. The RALE score showed good reliability with an intraclass correlation coefficient of 0.809 [95% confidence interval (CI), 0.760-0.848]. In univariable analysis, the RALE score had a hazard ratio (HR) of 1.19 (95% CI, 1.18-3.11), and the significance was maintained in multivariable analysis adjusting with age, ARDS etiology, and comorbidity, with an HR of 1.77 (95% CI, 1.05-2.91). The RALE score was a good predictor of ARDS-specific mortality, with a C-index of 0.607 (95% CI, 0.519-0.695).

CONCLUSION

The RALE score is a reliable measure for ARDS severity and a useful prognostic marker of mortality in children, especially for ARDS-specific mortality. This score provides information that clinicians can use to decide the proper time of aggressive therapy targeting severe lung injury and to appropriately manage the fluid balance of children with ARDS.

Cardiovascular Subphenotypes in ARDS: Diagnostic and Therapeutic Implications and Overlap with Other ARDS Subphenotypes

Acute respiratory distress syndrome (ARDS) is a highly heterogeneous clinical condition. Shock is a poor prognostic sign in ARDS, and heterogeneity in its pathophysiology may be a barrier to its effective treatment. Although right ventricular dysfunction is commonly implicated, there is no consensus definition for its diagnosis, and left ventricular function is neglected. There is a need to identify the homogenous subgroups within ARDS, that have a similar pathobiology, which can then be treated with targeted therapies. Haemodynamic clustering analyses in patients with ARDS have identified two subphenotypes of increasingly severe right ventricular injury, and a further subphenotype of hyperdynamic left ventricular function. In this review, we discuss how phenotyping the cardiovascular system in ARDS may align with haemodynamic pathophysiology, can aid in optimally defining right ventricular dysfunction and can identify tailored therapeutic targets for shock in ARDS. Additionally, clustering analyses of inflammatory, clinical and radiographic data describe other subphenotypes in ARDS. We detail the potential overlap between these and the cardiovascular phenotypes.

A Comparison of Intubation and Airway Complications Between COVID-19 and Non-COVID-19 Critically Ill Subjects

Introduction The number of subjects infected with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout the western hemisphere increased exponentially in the later months of 2020. With this increase in infection, the number of subjects requiring advanced ventilatory support increased concomitantly. We decided to compare the survival rates between coronavirus disease 2019 (COVID-19) subjects versus non-COVID-19 subjects undergoing intubation in the intensive care unit (ICU). We hypothesized that COVID-19 subjects would have lower rates of survival post-intubation. Methods We screened all subjects admitted to the adult critical care unit between January 2020 and June 2020 to determine if they met the inclusion criteria. These subjects were required to be spontaneously ventilating upon admission and eventually required intubation. Subjects were selected from our electronic health record (EHR) system EPIC© (Epic Systems, Verona, WI) through a retrospective ICU admission analysis. We identified and included 267 non-COVID-19 subjects and 56 COVID-19 subjects. Our primary outcome of interest was intubation-related mortality. We defined intubation mortality as unexpected death (within 48 hours of intubation). Our secondary outcomes were the length of stay in the ICU, length of time requiring ventilator support, and proportion of subjects requiring tracheostomy placement. Results Compared to non-coronavirus disease (COVID) subjects, COVID subjects were more likely to be intubated for acute respiratory distress. COVID subjects had longer stays in the ICU and longer ventilator duration than non-COVID subjects. COVID-positive subjects had a decreased hazard ratio for mortality (HR = 0.42, 95% CI: 0.20-0.87, P < 0.05) and increased chances of survival compared to non-COVID subjects. Conclusions We showed the rates of intubation survival were no different between the COVID and non-COVID groups. We attribute this finding to intubation preparation, a multidisciplinary team approach, and having the most experienced provider lead the intubation process.

Determinants of death in critically ill COVID-19 patients during the first wave of COVID-19: a multicenter study in Brazil

OBJECTIVE

To evaluate clinical outcomes and factors associated with mortality, focusing on secondary infections, in critically ill patients with COVID-19 in three Brazilian hospitals during the first pandemic wave.

METHODS

This was a retrospective observational study involving adult patients with COVID-19 admitted to one of the participating ICUs between March and August of 2020. We analyzed clinical features, comorbidities, source of SARS-CoV-2 infection, laboratory data, microbiology data, complications, and causes of death. We assessed factors associated with in-hospital mortality using logistic regression models.

RESULTS

We included 645 patients with a mean age of 61.4 years. Of those, 387 (60.0%) were male, 12.9% (83/643) had undergone solid organ transplant, and almost 10% (59/641) had nosocomial COVID-19 infection. During ICU stay, 359/644 patients (55.7%) required invasive mechanical ventilation, 225 (34.9%) needed renal replacement therapy, 337 (52.2%) received vasopressors, and 216 (33.5%) had hospital-acquired infections (HAIs), mainly caused by multidrug-resistant gram-negative bacteria. HAIs were independently associated with a higher risk of death. The major causes of death were refractory shock and multiple organ dysfunction syndrome but not ARDS, as previously reported in the literature.

CONCLUSIONS

In this study, most of our cohort required invasive mechanical ventilation and almost one third had HAIs, which were independently associated with a higher risk of death. Other factors related to death were Charlson Comorbidity Index, SOFA score at admission, and clinical complications during ICU stay. Nosocomial COVID-19 infection was not associated with death. The main immediate causes of death were refractory shock and multiple organ dysfunction syndrome.

Alveolar Biomarker Profiles in Subphenotypes of the Acute Respiratory Distress Syndrome

OBJECTIVES

We sought to determine whether hyperinflammatory acute respiratory distress syndrome (ARDS) and hypoinflammatory ARDS, which have been associated with differences in plasma biomarkers and mortality risk, also display differences in bronchoalveolar lavage (BALF) biomarker profiles. We then described the relationship between hyperinflammatory ARDS and hypoinflammatory ARDS to novel subphenotypes derived using BALF biomarkers.

DESIGN

Secondary analysis of a randomized control trial testing omega-3 fatty acids for the treatment of ARDS.

SETTING

Five North American intensive care units.

PATIENTS

Adults (n = 88) on invasive mechanical ventilation within 48 hours of ARDS onset.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We classified 57 patients as hypoinflammatory and 31 patients as hyperinflammatory using a previously validated logistic regression model. Of 14 BALF biomarkers analyzed, interleukin-6 and granulocyte colony stimulating factor were higher among patients with hyperinflammatory ARDS compared with hypoinflammatory ARDS, though the differences were not robust to multiple hypothesis testing. We then performed a de novo latent class analysis of the 14 BALF biomarkers to identify two classes well separated by alveolar profiles. Class 2 (n = 63) displayed significantly higher interleukin-6, von Willebrand factor, soluble programmed cell death receptor-1, % neutrophils, and other biomarkers of inflammation compared with class 1 (n = 25). These BALF-derived classes had minimal overlap with the plasma-derived hyperinflammatory and hypoinflammatory classes, and the majority of both plasma-derived classes were in BALF-derived class 2 and characterized by high BALF biomarkers. Additionally, the BALF-derived classes were associated with clinical severity of pulmonary disease, with class 2 exhibiting lower Pao2 to Fio2 and distinct ventilatory parameters, unlike the plasma-derived classes, which were only related to nonpulmonary organ dysfunction.

CONCLUSIONS

Hyperinflammatory and hypoinflammatory ARDS subphenotypes did not display significant differences in alveolar biologic profiles. Identifying ARDS subgroups using BALF measurements is a unique approach that complements information obtained from plasma, with potential to inform enrichment strategies in trials of lung-targeted therapies.

Acute respiratory distress syndrome in adults: diagnosis, outcomes, long-term sequelae, and management

Acute respiratory distress syndrome (ARDS) is characterised by acute hypoxaemic respiratory failure with bilateral infiltrates on chest imaging, which is not fully explained by cardiac failure or fluid overload. ARDS is defined by the Berlin criteria. In this Series paper the diagnosis, management, outcomes, and long-term sequelae of ARDS are reviewed. Potential limitations of the ARDS definition and evidence that could inform future revisions are considered. Guideline recommendations, evidence, and uncertainties in relation to ARDS management are discussed. The future of ARDS strives towards a precision medicine approach, and the framework of treatable traits in ARDS diagnosis and management is explored.

The Impact of Sample Size Misestimations on the Interpretation of ARDS Trials: Systematic Review and Meta-analysis

BACKGROUND

Indeterminate randomized controlled trials (RCTs) in ARDS may arise from sample size misspecification, leading to abandonment of efficacious therapies.

RESEARCH QUESTIONS

If evidence exists for sample size misspecification in ARDS RCTs, has this led to rejection of potentially beneficial therapies? Does evidence exist for prognostic enrichment in RCTs using mortality as a primary outcome?

STUDY DESIGN AND METHODS

We identified 150 ARDS RCTs commencing recruitment after the 1994 American European Consensus Conference ARDS definition and published before October 31, 2020. We examined predicted-observed sample size, predicted-observed control event rate (CER), predicted-observed average treatment effect (ATE), and the relationship between observed CER and observed ATE for RCTs with mortality and nonmortality primary outcome measures. To quantify the strength of evidence, we used Bayesian-averaged meta-analysis, trial sequential analysis, and Bayes factors.

RESULTS

Only 84 of 150 RCTs (56.0%) reported sample size estimations. In RCTs with mortality as the primary outcome, CER was overestimated in 16 of 28 RCTs (57.1%). To achieve predicted ATE, interventions needed to prevent 40.8% of all deaths, compared with the original prediction of 29.3%. Absolute reduction in mortality ≥ 10% was observed in 5 of 28 RCTs (17.9%), but predicted in 21 of 28 RCTs (75%). For RCTs with mortality as the primary outcome, no association was found between observed CER and observed ATE (pooled OR: β = -0.04; 95% credible interval, -0.18 to 0.09). We identified three interventions that are not currently standard of care with a Bayesian-averaged effect size of > 0.20 and moderate strength of existing evidence: corticosteroids, airway pressure release ventilation, and noninvasive ventilation.

INTERPRETATION

Reporting of sample size estimations was inconsistent in ARDS RCTs, and misspecification of CER and ATE was common. Prognostic enrichment strategies in ARDS RCTs based on all-cause mortality are unlikely to be successful. Bayesian methods can be used to prioritize interventions for future effectiveness RCTs.

Vasopressin versus norepinephrine as the first-line vasopressor in septic shock: A systematic review and meta-analysis

Background and Aim

Norepinephrine is currently the first-line vasopressor for septic shock. We conducted this meta-analysis to examine the outcomes of adult patients with septic shock who received vasopressin instead of norepinephrine.

Methods

We selected studies in adults with septic shock that compared the outcomes of patients treated with vasopressin versus norepinephrine. Cochrane ROB 2.0 and the Joanna Briggs Institute quality assessment tools were used to assess the risk of bias in RCTs and observational studies. Meta-analysis was conducted using RevMan 5.4.

Results

Eight studies were included in this meta-analysis. There were no significant differences in 28-day mortality rates (OR, 1.07; CI, 0.80-1.44) and intensive care unit (ICU) mortality (OR, 0.74; CI, 0.21-2.67) between the two groups. Similarly, length of ICU stay, length of hospital stay, mean arterial pressure at 24 h, urine output at 24 h, and serious adverse events also did not differ significantly. However, the odds of renal replacement therapy (RRT) requirement in the vasopressin group were substantially lower than in the norepinephrine group (OR, 0.68; CI, 0.47-0.98).

Conclusion

There were no differences in mortality, duration of hospitalization, and adverse effects in adults with septic shock across the two groups. However, the patients treated with vasopressin had lower chances of requiring RRT.

Relevance for Patients

Vasopressin use as the first-line vasopressor in septic shock showed a significant reduction in RRT, though there were no significant differences in terms of mortality and other adverse events. Therefore, vasopressin can be considered as a first-line vasopressor in septic shock patients with other risk factors which may contribute to renal failure requiring RRT.

Early Diuretics for De-resuscitation in Septic Patients With Left Ventricular Dysfunction

Introduction:

De-resuscitation practices in septic patients with heart failure (HF) are not well characterized. This study aimed to determine if diuretic initiation within 48 hours of intensive care unit (ICU) admission was associated with a positive fluid balance and patient outcomes.

Methods:

This single-center, retrospective cohort study included adult patients with an established diagnosis of HF admitted to the ICU with sepsis or septic shock. The primary outcome was the incidence of positive fluid balance in patients receiving early (<48 hours) versus late (>48 hours) initiation of diuresis. Secondary outcomes included hospital mortality, ventilator-free days, and hospital and ICU length of stay. Continuous variables were assessed using independent t-test or Mann-Whitney U, while categorical variables were evaluated using the Pearson Chi-squared test.

Results:

A total of 101 patients were included. Positive fluid balance was significantly reduced at 72 hours (−139 mL vs 4370 mL, P < .001). The duration of mechanical ventilation (4 vs 5 days, P = .129), ventilator-free days (22 vs 18.5 days, P = .129), and in-hospital mortality (28 (38%) vs 12 (43%), P = .821) were similar between groups. In a subgroup analysis excluding patients not receiving renal replacement therap (RRT) (n = 76), early diuretics was associated with lower incidence of mechanical ventilation (41 [73.2%] vs 20 (100%), P = .01) and reduced duration of mechanical ventilation (4 vs 8 days, P = .018).

Conclusions:

Diuretic use within 48 hours of ICU admission in septic patients with HF resulted in less incidence of positive fluid balance. Early diuresis in this unique patient population warrants further investigation.

Lung Transplantation for Acute Respiratory Distress Syndrome

In this review, we discuss the outcomes of patients with severe acute respiratory distress syndrome (ARDS). We discuss evidence that suggests that a significant proportion of patients with ARDS develop end-stage lung disease and die of pulmonary complications. In carefully selected patients with permanent lung damage, lung transplant can be a life-saving treatment.

The PANDORA Study: Prevalence and Outcome of Acute Hypoxemic Respiratory Failure in the Pre-COVID-19 Era

OBJECTIVES:

To establish the epidemiological characteristics, ventilator management, and outcomes in patients with acute hypoxemic respiratory failure (AHRF), with or without acute respiratory distress syndrome (ARDS), in the era of lung-protective mechanical ventilation (MV).

DESIGN:

A 6-month prospective, epidemiological, observational study.

SETTING:

A network of 22 multidisciplinary ICUs in Spain.

PATIENTS:

Consecutive mechanically ventilated patients with AHRF (defined as Pao₂/Fio₂ ≤ 300 mm Hg on positive end-expiratory pressure [PEEP] ≥ 5 cm H₂O and Fio₂ ≥ 0.3) and followed-up until hospital discharge.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

Primary outcomes were prevalence of AHRF and ICU mortality. Secondary outcomes included prevalence of ARDS, ventilatory management, and use of adjunctive therapies. During the study period, 9,803 patients were admitted: 4,456 (45.5%) received MV, 1,271 (13%) met AHRF criteria (1,241 were included into the study: 333 [26.8%] met Berlin ARDS criteria and 908 [73.2%] did not). At baseline, tidal volume was 6.9 ± 1.1 mL/kg predicted body weight, PEEP 8.4 ± 3.1 cm H₂O, Fio₂ 0.63 ± 0.22, and plateau pressure 21.5 ± 5.4 cm H₂O. ARDS patients received higher Fio₂ and PEEP than non-ARDS (0.75 ± 0.22 vs 0.59 ± 0.20 cm H₂O and 10.3 ± 3.4 vs 7.7 ± 2.6 cm H₂O, respectively [p < 0.0001]). Adjunctive therapies were rarely used in non-ARDS patients. Patients without ARDS had higher ventilator-free days than ARDS (12.2 ± 11.6 vs 9.3 ± 9.7 d; p < 0.001). All-cause ICU mortality was similar in AHRF with or without ARDS (34.8% [95% CI, 29.7–40.2] vs 35.5% [95% CI, 32.3–38.7]; p = 0.837).

CONCLUSIONS:

AHRF without ARDS is a very common syndrome in the ICU with a high mortality that requires specific studies into its epidemiology and ventilatory management. We found that the prevalence of ARDS was much lower than reported in recent observational studies.

The longitudinal course of pediatric acute respiratory distress syndrome and its time to resolution: A prospective observational study

BACKGROUND

The longitudinal course of patients with pediatric acute respiratory distress syndrome (PARDS) is not well described. In this study, we describe the oxygenation index (OI) and oxygen saturation index (OSI) in mild, moderate, and severe PARDS over 28 days and provide pilot data for the time to resolution of PARDS (T _res), as a short-term respiratory-specific outcome, hypothesizing that it is associated with the severity of PARDS and clinical outcomes.

METHODS

This prospective observational study recruited consecutive patients with PARDS. OI and OSI were trended daily over 28 days. T _res (defined as OI < 4 or OSI < 5.3 on 2 consecutive days) were described based on PARDS severity and analyzed with Poisson and logistic regression to determine its association with conventional outcomes [mechanical ventilation (MV) duration, intensive care unit (ICU) and hospital length of stay, 28-day ventilator-free days (VFD), and 28-day ICU-free days (IFD)].

RESULTS

There were 121 children included in this study, 33/121(27.3%), 44/121(36.4%), and 44/121(36.4%) in the mild, moderate, and severe groups of PARDS, respectively. OI and OSI clearly differentiated mild, moderate, and severe groups in the first 7days of PARDS; however, this differentiation was no longer present after 7days. Median T _res was 4 (interquartile range: 3, 6), 5 (4, 7), and 7.5 (7, 11.5) days; p < 0.001 for the mild, moderate, and severe groups of PARDS, respectively. T _res was associated with increased MV duration, ICU and hospital length of stay, and decreased VFD and IFD.

CONCLUSION

The oxygenation defect in PARDS took progressively longer to resolve across the mild, moderate, and severe groups. T _res is a potential short-term respiratory-specific outcome, which may be useful in addition to conventional clinical outcomes but needs further validation in external cohorts.

Pulmonary barotrauma in COVID-19: A systematic review and meta-analysis

BACKGROUND

An ever-increasing number of studies have reported an increased incidence of spontaneous pulmonary barotrauma such as pneumothorax, pneumomediastinum, and subcutaneous emphysema in patients with COVID-19. We conducted this systematic review and meta-analysis to assess the value and significance of the available data.

METHODS

A thorough systematic search was conducted to identify studies of barotrauma in hospitalized patients with COVID-19. Data analysis of case reports was done using a statistical package for the social sciences (SPSS) version 22, and meta-analysis was performed using CMA-3.

RESULTS

We identified a total of 4488 studies after thorough database searching.118 case reports and series, and 15 observational studies were included in the qualitative analysis. Fifteen studies were included in the quantitative analysis. The observational studies reported barotrauma in 4.2% (2.4-7.3%) among hospitalized patients; 15.6% (11-21.8%) among critically ill patients; and 18.4% (13-25.3%) in patients receiving invasive mechanical ventilation, showing a linear relationship of barotrauma with the severity of the disease. In addition, barotrauma was associated with a longer length of hospital stay, more extended ICU stay, and higher in-hospital mortality. Also, a slightly higher odds of barotrauma was seen in COVID-19 ARDS compared with non-COVID-19 ARDS.

CONCLUSION

COVID-19 pneumonia is associated with a higher incidence of barotrauma. It presents unique challenges for invasive and non-invasive ventilation management. Further studies are required to unravel the underlying pathophysiology and develop safer management strategies.

Effect of Intubation Timing on the Outcome of Patients With Severe Respiratory Distress Secondary to COVID-19 Pneumonia

Background

The optimal timing of intubation for critically ill patients with severe respiratory illness remains controversial among healthcare providers. The coronavirus disease 2019 (COVID-19) pandemic has raised even more questions about when to implement this life-saving therapy. While one group of providers prefers early intubation for patients with respiratory distress because these patients may deteriorate rapidly without it, other providers believe that intubation should be delayed or avoided because of its associated risks including worse outcomes.

Research question

Our objective was to assess whether the timing of intubation in patients with severe COVID-19 pneumonia was associated with differences in mortality or other outcomes.

Study design and methods

This was a single-center retrospective observational cohort study. We analyzed outcomes of patients who were intubated secondary to COVID-19 pneumonia between March 13, 2020, and December 12, 2020, at Henry Ford Hospital in Detroit, Michigan. Patients were categorized into two groups: early intubated (intubated within 24 hours of the onset of severe respiratory distress) and late intubated (intubated after 24 hours of the onset of severe respiratory distress). Demographics, comorbidities, respiratory rate oxygenation (ROX) index, sequential organ failure assessment (SOFA) score, and treatment received were compared between groups. The primary outcome was mortality. Secondary outcomes were ventilation time, intensive care unit stay, hospital length of stay, and discharge disposition. Post hoc and Kaplan-Meier survival analyses were performed.

Results

A total of 110 patients were included: 55 early intubated and 55 late intubated. We did not observe a significant difference in overall mortality between the early intubated (43%) and the late intubated groups (53%) (p = 0.34). There was no statistically significant difference in patients' baseline characteristics including SOFA scores (the early intubation group had a mean score of 7.5 compared to 6.7 in the late intubation group). Based on the ROX index, the early intubation group had significantly more patients with a reduced risk of intubation (45%) than the late group (27%) (p = 0.029). The early intubation group was treated with a high-flow nasal cannula at a significantly lower rate (47%) than the late intubation group (83%) (p < 0.001). Significant differences in patient baseline characteristics, treatment received, and other outcomes were not observed. Post hoc analysis adjusting for SOFA score between 0 and 9 revealed significantly higher mortality in the late intubation group (49%) than in the early intubation group (26%) (p = 0.03). Patients in the 0 to 9 SOFA group who were intubated later had 2.7 times the odds of dying during hospital admission compared to patients who were intubated early (CI, 1.09-6.67).

Interpretation

The timing of intubation for patients with severe COVID-19 pneumonia was not significantly associated with overall mortality or other patient outcomes. However, within the subgroup of patients with SOFA scores of 9 or lower at the time of intubation, patients intubated after 24 hours of the onset of respiratory distress had a higher risk of death than those who were intubated within 24 hours of respiratory distress. Thus, patients with COVID-19 pneumonia who are not at a high level of organ dysfunction may benefit from early mechanical ventilation.

Risk of post-intubation cardiac arrest with the use of high-dose rocuronium in COVID-19 patients with acute respiratory distress syndrome: A retrospective cohort study

BACKGROUND

Post-intubation cardiac arrest (PICA) is an uncommon complication of intubation, but numbers have risen to over 1.5 times the usual number since the coronavirus disease 2019 (COVID-19) pandemic. Due to expert recommendations, high-dose rocuronium (HDR) has become a commonly used pre-intubation neuromuscular blocking agent.

AIM

We conducted this retrospective case-control observational study with the hypothesis that high-dose rocuronium was not associated with higher incidence of PICA.

METHODS

We included 93 patients who were intubated using the rapid sequence intubation (RSI) technique with rocuronium for acute respiratory distress syndrome (ARDS) due to confirmed COVID-19 pneumonia, admitted from March 2020 to February 2021 to a tertiary care hospital in North Carolina, USA. The patients were grouped based on high (1.5 mg/kg of ideal body weight and above) versus low (<1.5 mg/kg of ideal body weight) dose rocuronium used for RSI. The differences of the various outcomes between the groups were analyzed.

RESULTS

The baseline demographics were similar in both groups except for higher body mass index in high-dose group 39 versus 32 (kg/m²), p = 0.009. There was a total of six PICA events (6.45%). The HDR group had 8.0% of PICA versus 4.7% in the low-dose group. In-hospital mortality was 60.0% in the HDR group versus 72.1% in the low-dose group.

CONCLUSION

The incidence of PICA in COVID-19 patients with ARDS who were intubated using the RSI technique was higher than in the pre-COVID-19 era.

RELEVANCE FOR PATIENTS

The use of high-dose paralytics during invasive ventilation with RSI and their consequences should be explored with the help of large-scale studies. The rate of PICA is still very low, and perhaps, the use of HDR is safe, as suggested by the expert panel.

Sepsis in patients hospitalized with coronavirus disease 2019: how often and how severe?

PURPOSE OF REVIEW

To discuss why severe COVID-19 should be considered sepsis and how co-infection and secondary infection can aggravate this condition and perpetuate organ dysfunction leading to high mortality rates.

RECENT FINDINGS

In severe COVID-19, there is both direct viral toxicity and dysregulated host response to infection. Although both coinfection and/or secondary infection are present, the latest is of greater concern mainly in resource-poor settings. Patients with severe COVID-19 present a phenotype of multiorgan dysfunction that leads to death in an unacceptable high percentage of the patients, with wide variability around the world. Similarly to endemic sepsis, the mortality of COVID-19 critically ill patients is higher in low-income and middle-income countries as compared with high-income countries. Disparities, including hospital strain, resources limitations, higher incidence of healthcare-associated infections (HAI), and staffing issues could in part explain this variability.

SUMMARY

The high mortality rates of critically ill patients with severe COVID-19 disease are not only related to the severity of patient disease but also to modifiable factors, such as the ICU strain, HAI incidence, and organizational aspects. Therefore, HAI prevention and the delivery of best evidence-based care for these patients to avoid additional damage is important. Quality improvement interventions might help in improving outcomes mainly in resource-limited settings.

Luteolin activates Tregs to promote IL-10 expression and alleviating caspase-11-dependent pyroptosis in sepsis-induced lung injury

OBJECTIVES

Acute respiratory distress syndrome (ARDS) is characterized by an excessive pulmonary inflammatory response. Pyroptosis is a newly form of programmed inflammatory cell death that is triggered by inflammatory caspases. Studies have shown that Luteolin has powerful anti-inflammation effects through activating the function of regulatory T cells (Tregs). The study aimed at investigating the effects of Luteolin on CLP-induced ALI.

METHODS

In our study, we employed the mouse cecal ligation and puncture (CLP) model to explore whether Luteolin contributed to alleviated lung injury in vivo. H&E staining and wet/dry (W/D) weight ratios were used to evaluate the severity of lung injury. The serum and BALF of cytokines were assessed by ELISA. The number of neutrophils in the BALF was counted. Immunohistochemistry of IL-10 and MPO in lung tissue was detected. The ROS level in lung was tested by ROS Assay Kit and expression of Gpx4 in lung tissue was detected by qRT-PCR and Western blotting. The regulatory T cells (Treg) population was analyzed in spleen and Peripheral blood mononuclear cells (PBMCs). The levels of caspase-11 protein, caspase-1 protein, GSDMD protein, IL-1α and IL-1β protein in the lung tissue was evaluated by Western blotting.

RESULTS

We found Luteolin significantly inhibits inflammation and attenuated CLP-induced lung injury in vivo, and the levels of, caspase-11, caspase-1, GSDMD, IL-1α and IL-1β protein in the lungs of CLP mice decreased significantly after pretreatment with Luteolin. Furthermore, the results showed that Luteolin could increase Treg frequencies and IL-10 levels in serum and BALF of CLP mice. It is noteworthy that depleting Tregs reverse Luteolin ameliorated lung injury, and IL-10 neutralizing antibodies treatment aggravated lung pyroptosis.

CONCLUSIONS

Our study illustrated that Luteolin contributed to alleviated lung injury, and attenuated caspase-11-dependent pyroptosis in the lung tissue of the CLP-induced ALI mouse model. The mechanisms could be related to regulating the frequency of Tregs and the levels of Treg derived IL-10. Treg cells were show to produce IL-10 and could alleviating caspase-11-dependent lung pyroptosis.

Validating Measures of Disease Severity in Acute Respiratory Distress Syndrome

Rationale: Quantifying acute respiratory disease syndrome (ARDS) severity is essential for prognostic enrichment to stratify patients for invasive or higher-risk treatments; however, the comparative performance of many ARDS severity measures is unknown.Objectives: To validate ARDS severity measures for their ability to predict hospital mortality and an ARDS-specific outcome (defined as death from pulmonary dysfunction or the need for extracorporeal membrane oxygenation [ECMO] therapy).Methods: We compared five individual ARDS severity measures including the ratio of arterial oxygen tension/pressure to fraction of inspired oxygen (Pa_O2/Fi_O2 ratio), oxygenation index, ventilatory ratio, lung compliance, and radiologic assessment of lung edema (RALE); two ARDS composite severity scores including the Murray Lung Injury Score, and a novel score combining RALE, Pa_O2/Fi_O2 ratio, and ventilatory ratio; and the Acute Physiology and Chronic Health Evaluation IV score, using data collected at ARDS onset in patients hospitalized at a single center in 2016 and 2017. Discrimination of hospital mortality and the ARDS-specific outcome was evaluated using the area under the receiver operator characteristic curve (AUROC). Measure calibration was also evaluated.Results: Among 340 patients with ARDS, 125 (37%) died during hospitalization and 36 (10.6%) had the ARDS-specific outcome, including one who received ECMO. Among the five individual ARDS severity measures, the RALE score had the highest discrimination of the ARDS-specific outcome (AUROC = 0.67; 95% confidence interval [CI], 0.58-0.77), although other ARDS severity measures had similar performance. However, their ability to discriminate overall mortality was low. In contrast, the Acute Physiology and Chronic Health Evaluation IV score best discriminated overall mortality (AUROC = 0.73; 95% CI, 0.67-0.79) but was unable to discriminate the ARDS-specific outcome (AUROC = 0.54; 95% CI, 0.44-0.65). Among ARDS composite severity scores, the lung injury score had an AUROC = 0.67 (95% CI, 0.58-0.75) for the ARDS-specific outcome whereas the novel score had an AUROC = 0.70 (95% CI, 0.61-0.79). Patients grouped by quartile of the novel score had a 6%, 2%, 10%, and 24% rate of the ARDS-specific outcome.Conclusions: Although most ARDS severity measures had poor discrimination of hospital mortality, they performed better at predicting death from severe pulmonary dysfunction or ECMO needs. A novel composite score had the highest discrimination of this outcome.

Effect of thiamine supplementation in critically ill patients: A systematic review and meta-analysis

INTRODUCTION

Several studies have previously shown the benefit of thiamine supplementation in critically ill patients. In order to fully appraise the available data, we performed a meta-analysis of 18 published studies.

METHODS

A thorough systematic search was conducted. The studies enrolling critically ill patients receiving thiamine supplementation was compared with the standard of care (SOC) group. Data was analyzed using RevMan 5.4. Clinical outcomes were pooled using Odds Ratio (OR) and mean differences.

RESULT

Eighteen studies (8 RCTs and 10 cohort studies) met the criteria for quantitative synthesis. In the analysis of RCTs, thiamine supplementation showed 42% lower odds of developing ICU delirium (OR 0.58, 95% CI, 0.34-0.98). A reduction in mortaliy was observed on performing fixed effect model analysis however, a level of statistical significance could not be reached on performing randon effect model analysis (OR, 0.78; 95% CI, 0.59 to 1.04). Further sub-group analysis of 13 studies in patients with sepsis, there was no difference in mortality between the two groups (OR, 0.83; 95% CI, 0.63 to 1.09).

CONCLUSION

Thiamine supplementation in critically ill patients showed a reduction in the incidence of ICU delirium among RCTs. However, there was no significant benefit in terms of overall mortality, and mortality in patients with sepsis. Further, large scale randomized prospective studies are warranted to investigate the role of thiamine supplementation in critically ill patients.

In-hospital mortality of pulmonary tuberculosis with acute respiratory failure and related clinical risk factors

Background/objective

Data on acute respiratory failure (ARF) in pulmonary tuberculosis (PTB) patients is limited. This study aims to investigate in-hospital mortality, its clinical risk factors and the accuracy of the existing scoring system in predicting in-hospital mortality.

Methods

An observational prospective cohort study involving PTB patients with ARF in tertiary hospital, between January 2017 and December 2018, was conducted. The in-hospital mortality was predicted using the National Early Warning Score 2 (NEWS2), quick Sequential Organ Failure Assessment (qSOFA) and CRB-65. Regression models were run to analyze the clinical risk factors for in-hospital Mortality. Sensitivity and specificity of scoring systems were calculated using a Wilson score interval.

Results

A total of 111 subjects were included. Most of subjects were hypoxemic type respiratory failure (68.5%), advanced lesions (62.2%), new cases (70.3%) and pneumonia co-infection (72.1%) patients. Invasive mechanical ventilation was utilized for 29.73% of cases. There were 53 (47.75%) in-hospital mortality cases and its risk factors were intensive phase treatment (3.34 OR; CI95% 1.27-8.78), P/F ratio < 100 (OR 4.30; CI 95% 1.75-10.59) and renal insufficiency (4.09 OR; CI95% 1.46-11.49). The sensitivity and specificity of NEWS2 ≥ 6, qSOFA ≥ 2 and CRB-65 ≥ 2 were 62.26% and 67.24%; 60.38% and 72.41%; 41.51% and 84.48% respectively.

Conclusions

Most of PTB with ARF were new cases, advanced lesion and hypoxemic type respiratory failure. Intensive phase treatment, severe hypoxemia and renal insufficiency are independent predictors of in-hospital mortality in PTB patients with ARF. NEWS2, qSOFA and CRB-65 scores were poor to predict the in-hospital mortality.