The acute respiratory distress syndrome (ARDS) was defined in 1994 by the American-European Consensus Conference (AECC); since then, issues regarding the reliability and validity of this definition have emerged. Using a consensus process, a panel of experts convened in 2011 (an initiative of the European Society of Intensive Care Medicine endorsed by the American Thoracic Society and the Society of Critical Care Medicine) developed the Berlin Definition, focusing on feasibility, reliability, validity, and objective evaluation of its performance. A draft definition proposed 3 mutually exclusive categories of ARDS based on degree of hypoxemia: mild (200 mm Hg < PaO2/FIO2 ≤ 300 mm Hg), moderate (100 mm Hg < PaO2/FIO2 ≤ 200 mm Hg), and severe (PaO2/FIO2 ≤ 100 mm Hg) and 4 ancillary variables for severe ARDS: radiographic severity, respiratory system compliance (≤40 mL/cm H2O), positive end-expiratory pressure (≥10 cm H2O), and corrected expired volume per minute (≥10 L/min). The draft Berlin Definition was empirically evaluated using patient-level meta-analysis of 4188 patients with ARDS from 4 multicenter clinical data sets and 269 patients with ARDS from 3 single-center data sets containing physiologic information. The 4 ancillary variables did not contribute to the predictive validity of severe ARDS for mortality and were removed from the definition. Using the Berlin Definition, stages of mild, moderate, and severe ARDS were associated with increased mortality (27%; 95% CI, 24%-30%; 32%; 95% CI, 29%-34%; and 45%; 95% CI, 42%-48%, respectively; P < .001) and increased median duration of mechanical ventilation in survivors (5 days; interquartile [IQR], 2-11; 7 days; IQR, 4-14; and 9 days; IQR, 5-17, respectively; P < .001). Compared with the AECC definition, the final Berlin Definition had better predictive validity for mortality, with an area under the receiver operating curve of 0.577 (95% CI, 0.561-0.593) vs 0.536 (95% CI, 0.520-0.553; P < .001). This updated and revised Berlin Definition for ARDS addresses a number of the limitations of the AECC definition. The approach of combining consensus discussions with empirical evaluation may serve as a model to create more accurate, evidence-based, critical illness syndrome definitions and to better inform clinical care, research, and health services planning.

Although corticosteroids are widely used for adults with sepsis, both the overall benefit and potential risks remain unclear.To conduct a systematic review and meta-analysis of the efficacy and safety of corticosteroids in patients with sepsis.MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception until March 20, 2018, and updated on August 10, 2018. The terms corticosteroids, sepsis, septic shock, hydrocortisone, controlled trials, and randomized controlled trial were searched alone or in combination. Randomized clinical trials (RCTs) were included that compared administration of corticosteroids with placebo or standard supportive care in adults with sepsis.Meta-analyses were conducted using a random-effects model to calculate risk ratios (RRs) and mean differences (MDs) with corresponding 95% CIs. Two independent reviewers completed citation screening, data abstraction, and risk assessment.Twenty-eight-day mortality.This meta-analysis included 37 RCTs (N = 9564 patients). Eleven trials were rated as low risk of bias. Corticosteroid use was associated with reduced 28-day mortality (RR, 0.90; 95% CI, 0.82-0.98; I2 = 27%) and intensive care unit (ICU) mortality (RR, 0.85; 95% CI, 0.77-0.94; I2 = 0%) and in-hospital mortality (RR, 0.88; 95% CI, 0.79-0.99; I2 = 38%). Corticosteroids were significantly associated with increased shock reversal at day 7 (MD, 1.95; 95% CI, 0.80-3.11) and vasopressor-free days (MD, 1.95; 95% CI, 0.80-3.11) and with ICU length of stay (MD, -1.16; 95% CI, -2.12 to -0.20), the sequential organ failure assessment score at day 7 (MD, -1.38; 95% CI, -1.87 to -0.89), and time to resolution of shock (MD, -1.35; 95% CI, -1.78 to -0.91). However, corticosteroid use was associated with increased risk of hyperglycemia (RR, 1.19; 95% CI, 1.08-1.30) and hypernatremia (RR, 1.57; 95% CI, 1.24-1.99).The findings suggest that administration of corticosteroids is associated with reduced 28-day mortality compared with placebo use or standard supportive care. More research is needed to associate personalized medicine with the corticosteroid treatment to select suitable patients who are more likely to show a benefit.

Excessive inflammation induced by cytokine storm and coagulation disorders is considered the primary characteristic of smoke inhalation-induced acute lung injury (SI-ALI). Glucocorticoids such as methylprednisolone (MP) are commonly used to treat patients with inflammatory diseases; however, the management of ALI or acute respiratory distress syndrome (ARDS) remains controversial. We explored the effects of different MP doses and durations in a rat SI-ALI model. SI-ALI model rats had a high mortality rate and severe lung injury with proinflammatory, procoagulant, and pro-fibrotic changes. We found that a medium MP dose (4 mg/kg) markedly improved survival rates compared with low (0.4 mg/kg) and high (40 mg/kg) doses in the acute phase. A medium dose significantly attenuated lung injury, and reduced proinflammatory cytokine production and neutrophil infiltration into alveoli. Both medium and high MP doses improved coagulation and fibrinolysis conditions compared with low-dose MP. We also explored the effect of different durations of MP treatment on attenuating fibrotic changes in late-phase SI-ALI Pro-fibrotic chemokine levels were gradually increased, followed by an increase in collagen and fibrin deposition after smoke inhalation. Three and 7-day MP treatments significantly attenuated this process, which was reflected by a reduction in pro-fibrotic chemokine levels. There was no significant difference between 3- and 7-day treatments. We report that a medium MP (4 mg/kg) dose significantly reduced inflammation and coagulation disorders, as well as acute-phase mortality. Three-day MP treatment may sufficiently attenuate fibrotic changes in late-phase SI-ALI.

The aim of this study was to describe the role of glucocorticoids in immune modulation during critical illness and to review clinical trials and recent meta-analyses of glucocorticoids in early and late acute respiratory distress syndrome (ARDS). Selected reviews of publications, clinical trials, and meta-analyses were considered for the study. Activation of the adrenal axis is an important component of the compensatory anti-inflammatory response to critical illness. A recent meta-analysis of high doses of corticosteroids in patients with or at risk for ARDS demonstrated a trend for greater risk of the development of ARDS and a fatal outcome. Additional meta-analyses of four randomized trials and five cohort studies in patients with established ARDS or pneumonia indicated an overall mortality benefit with corticosteroids but this finding was not confirmed in another meta-analysis limited to randomized trials and excluding the trial focused on pneumonia. Lung function is improved and the duration of mechanical ventilation is reduced with prolonged administration of lower doses. In conclusion, short-duration, high-dose glucocorticoid therapy is not effective in preventing ARDS and may be harmful. Lower doses for persistent ARDS improve lung function and shorten the duration of mechanical ventilation but the impact on long-term mortality is unclear. Additional trials are needed to determine if corticosteroids improve important clinical outcomes before they can be recommended for the routine use of patients with unresolved ARDS.

Current concepts on the role of glucocorticoid hormones in the regulation of inflammatory and immune responses depict this role as being inhibitory. Over the past decade, however, a large variety of studies have shown that glucocorticoids also exert stimulatory effects on immune function, suggesting that the present concept of the role of glucocorticoids in the immune system in not sufficient and needs to be extended. Here, Jan Wiegers and Hans Reul ask how these apparently paradoxical effects fit together and what their functional and pathological significance might be.

There is no proven specific pharmacological treatment for patients with the acute respiratory distress syndrome (ARDS). The efficacy of corticosteroids in ARDS remains controversial. We aimed to assess the effects of dexamethasone in ARDS, which might change pulmonary and systemic inflammation and result in a decrease in duration of mechanical ventilation and mortality.We did a multicentre, randomised controlled trial in a network of 17 intensive care units (ICUs) in teaching hospitals across Spain in patients with established moderate-to-severe ARDS (defined by a ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen of 200 mm Hg or less assessed with a positive end-expiratory pressure of 10 cm HO or more and FiO of 0·5 or more at 24 h after ARDS onset). Patients with brain death, terminal-stage disease, or receiving corticosteroids or immunosuppressive drugs were excluded. Eligible patients were randomly assigned based on balanced treatment assignments with a computerised randomisation allocation sequence using blocks of 10 opaque, sealed envelopes to receive immediate treatment with dexamethasone or continued routine intensive care (control group). Patients in the dexamethasone group received an intravenous dose of 20 mg once daily from day 1 to day 5, which was reduced to 10 mg once daily from day 6 to day 10. Patients in both groups were ventilated with lung-protective mechanical ventilation. Allocation concealment was maintained at all sites during the trial. Primary outcome was the number of ventilator-free days at 28 days, defined as the number of days alive and free from mechanical ventilation from day of randomisation to day 28. Secondary outcome was all-cause mortality 60 days after randomisation. All analyses were done according to the intention-to-treat principle. This study is registered with ClinicalTrials.gov, NCT01731795.Between March 28, 2013, and Dec 31, 2018, we enrolled 277 patients and randomly assigned 139 patients to the dexamethasone group and 138 to the control group. The trial was stopped by the data safety monitoring board due to low enrolment rate after enrolling more than 88% (277/314) of the planned sample size. The mean number of ventilator-free days was higher in the dexamethasone group than in the control group (between-group difference 4·8 days [95% CI 2·57 to 7·03]; p<0·0001). At 60 days, 29 (21%) patients in the dexamethasone group and 50 (36%) patients in the control group had died (between-group difference -15·3% [-25·9 to -4·9]; p=0·0047). The proportion of adverse events did not differ significantly between the dexamethasone group and control group. The most common adverse events were hyperglycaemia in the ICU (105 [76%] patients in the dexamethasone group vs 97 [70%] patients in the control group), new infections in the ICU (eg, pneumonia or sepsis; 33 [24%] vs 35 [25%]), and barotrauma (14 [10%] vs 10 [7%]).Early administration of dexamethasone could reduce duration of mechanical ventilation and overall mortality in patients with established moderate-to-severe ARDS.Fundación Mutua Madrileña, Instituto de Salud Carlos III, The European Regional Development's Funds, Asociación Científica Pulmón y Ventilación Mecánica.Copyright © 2020 Elsevier Ltd. All rights reserved.

Authors of recent meta-analyses have reported that prolonged glucocorticoid treatment is associated with significant improvements in patients with severe pneumonia or acute respiratory distress syndrome (ARDS) of multifactorial etiology. A prospective randomized trial limited to patients with sepsis-associated ARDS is lacking. The objective of our study was to evaluate the efficacy of hydrocortisone treatment in sepsis-associated ARDS.In this double-blind, single-center (Siriraj Hospital, Bangkok), randomized, placebo-controlled trial, we recruited adult patients with severe sepsis within 12 h of their meeting ARDS criteria. Patients were randomly assigned (1:1 ratio) to receive either hydrocortisone 50 mg every 6 h or placebo. The primary endpoint was 28-day all-cause mortality; secondary endpoints included survival without organ support on day 28.Over the course of 4 years, 197 patients were randomized to either hydrocortisone (n = 98) or placebo (n = 99) and were included in this intention-to-treat analysis. The treatment group had significant improvement in the ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen and lung injury score (p = 0.01), and similar timing to removal of vital organ support (HR 0.74, 95 % CI 0.51-1.07; p = 0.107). After adjustment for significant covariates, day 28 survival was similar for the whole group (HR 0.80, 95 % CI 0.46-1.41; p = 0.44) and for the larger subgroup (n = 126) with Acute Physiology and Chronic Health Evaluation II score <25 (HR 0.57, 95 % CI 0.24-1.36; p = 0.20). With the exception of hyperglycemia (80.6 % vs. 67.7 %; p = 0.04), the rate of adverse events was similar. Hyperglycemia had no impact on outcome.In sepsis-associated ARDS, hydrocortisone treatment was associated with a significant improvement in pulmonary physiology, but without a significant survival benefit.ClinicalTrials.gov identifier NCT01284452 . Registered on 18 January 2011.

Background: Most meta-analyses in systematic reviews, including Cochrane ones, do not have sufficient statistical power to detect or refute even large intervention effects. This is why a meta-analysis ought to be regarded as an interim analysis on its way towards a required information size. The results of the meta-analyses should relate the total number of randomised participants to the estimated required meta-analytic information size accounting for statistical diversity. When the number of participants and the corresponding number of trials in a meta-analysis are insufficient, the use of the traditional 95% confidence interval or the 5% statistical significance threshold will lead to too many false positive conclusions (type I errors) and too many false negative conclusions (type II errors).Methods: We developed a methodology for interpreting meta-analysis results, using generally accepted, valid evidence on how to adjust thresholds for significance in randomised clinical trials when the required sample size has not been reached.Results: The Lan-DeMets trial sequential monitoring boundaries in Trial Sequential Analysis offer adjusted confidence intervals and restricted thresholds for statistical significance when the diversity-adjusted required information size and the corresponding number of required trials for the meta-analysis have not been reached. Trial Sequential Analysis provides a frequentistic approach to control both type I and type II errors. We define the required information size and the corresponding number of required trials in a meta-analysis and the diversity (D-2) measure of heterogeneity. We explain the reasons for using Trial Sequential Analysis of meta-analysis when the actual information size fails to reach the required information size. We present examples drawn from traditional meta-analyses using unadjusted naive 95% confidence intervals and 5% thresholds for statistical significance. Spurious conclusions in systematic reviews with traditional meta-analyses can be reduced using Trial Sequential Analysis. Several empirical studies have demonstrated that the Trial Sequential Analysis provides better control of type I errors and of type II errors than the traditional naive meta-analysis.Conclusions: Trial Sequential Analysis represents analysis of meta-analytic data, with transparent assumptions, and better control of type I and type II errors than the traditional meta-analysis using naive unadjusted confidence intervals.

The mortality of the acute respiratory distress syndrome (ARDS) is still very high. There is some evidence based on case series suggesting that corticosteroids may be beneficial in the chronic fibroproliferative state of the disease. In a retrospective study we analysed the data of 31 non-trauma ARDS patients who had been on mechanical ventilation for at least 7 days. Thirteen cases received corticosteroids at a dosage equivalent to 100-250 mg methylprednisolone at the discretion of the attending physician in charge. Apart from corticosteroid administration, supportive care was identical in the treated and non-treated patient subgroups. Both groups were comparable regarding the relevant demographic, clinical and physiologic data, Apache-II score, radiological score, lung injury score and multiple organ failure score. Mortality in the treatment group was 38% (5/13) as opposed to 67% (12/18) in the untreated group (p = 0.117). There was a significant improvement in the PaO2/FIO2 ratio from a median of -26 to +5 mm Hg measured in a 48-hour period before and after corticosteroid treatment (p = 0.039). The response to corticosteroid therapy could not be predicted on the basis of clinical or physiologic data. Five patients responded within 48 h, and 3 showed a delayed response after 5-6 days. There were no significant complications attributable to corticosteroid treatment.Although the data of this first comparative study were retrospective, they suggest a beneficial effect of corticosteroid treatment in patients with established fibroproliferative ARDS. A prospective clinical trial, however, is highly warranted in order to fully elucidate the true effect of this therapeutic approach under controlled conditions.

Pulmonary fibroproliferation (PFP) is directly or indirectly the leading cause of death in patients with late ARDS. We previously reported our experience using intravenous corticosteroids (IVC) in 8 patients with late ARDS and now have expanded our observation to a total of 25 patients with severe fibroproliferation (mean lung injury score [LIS] 3) and progressive respiratory failure (RF). Thirteen patients had open-lung biopsy before treatment. Patients were started on IVC treatment (IVCT) an average of 15 +/- 7.5 days into mechanical ventilation (MV). Significant physiologic improvement (SPI) to IVCT was defined as a reduction in LIS of greater than 1 point or an increase in PaO2:FIO2 ratio of greater than 100. We observed three patterns of response: rapid responders (RR) had an SPI by day 7 (n = 15); delayed responders (DR) had an SPI by day 14 (n = 6); nonresponders (NR) were without SPI by day 14 (n = 4). Overall the following significant mean changes were seen within 7 days of IVCT: LIS from 3 to 2 (p = 0.001), PaO2:FIO2 from 162 to 234 (p = 0.0004), PEEP from 11 to 6.8 cm H2O (p = 0.001), chest radiograph score from 3.8 to 3.0 (p = 0.009), and VE from 16 to 13.6 L/min (p = 0.01). Development of pneumonia was related to the pattern of response. Surveillance bronchoscopy was effective in identifying pneumonia in eight afebrile patients. Nineteen of 25 (76 percent) patients survived the ICU admission. Comparisons were made between survivors (S) and nonsurvivors (NS) and among the three groups of responders. At the time ARDS developed, no physiologic or demographic variable could discriminate between S and NS. At the time of IVCT, only liver failure was more frequent in nonsurvivors (p = 0.035). Histologic findings at open-lung biopsy and pattern of physiologic response clearly predicted outcome. The presence of preserved alveolar architecture (p = 0.045), myxoid type fibrosis (p = 0.045), coexistent intraluminal bronchiolar fibrosis (p = 0.0045), and lack of arteriolar subintimal fibroproliferation (p = 0.045) separated S from NS. ICU survival rate was 86 percent in responders and 25 percent in nonresponders (p = 0.03). Only one death resulted from refractory respiratory failure.

Severe sepsis is common and frequently fatal, and community-acquired pneumonia (CAP) is the leading cause. Although severe sepsis is often attributed to uncontrolled and unbalanced inflammation, evidence from humans with infection syndromes across the breadth of disease is lacking. In this study we describe the systemic cytokine response to pneumonia and determine if specific patterns, including the balance of proinflammatory and anti-inflammatory markers, are associated with severe sepsis and death.This is a cohort study of 1886 subjects hospitalized with CAP through the emergency departments in 28 US academic and community hospitals. We defined severe sepsis as CAP complicated by new-onset organ dysfunction, following international consensus conference criteria. We measured plasma tumor necrosis factor, IL-6 (interleukin 6), and IL-10 levels daily for the first week and weekly thereafter. Our main outcome measures were severe sepsis and 90-day mortality.A total of 583 patients developed severe sepsis (31%), of whom 149 died (26%). Systemic cytokine level elevation occurred in 82% of all subjects with CAP. Mean cytokine concentrations were highest at presentation, declined rapidly over the first few days, but remained elevated throughout the first week, beyond resolution of clinical signs of infection. Cytokine levels were highest in fatal severe sepsis and lowest in CAP with no severe sepsis. Unbalanced (high/low) cytokine patterns were unusual (4.6%) and not associated with decreased survival. Highest risk of death was with combined high levels of the proinflammatory IL-6 and anti-inflammatory IL-10 cytokine activity (hazard ratio, 20.5; 95% confidence interval, 10.8-39.0) (P<.001).The circulating cytokine response to pneumonia is heterogeneous and continues for more than a week after presentation, with considerable overlap between those who do and do not develop severe sepsis. Unbalanced activation is uncommon, and mortality is highest when both proinflammatory and anti-inflammatory cytokine levels are high.

This study was performed to evaluate the impact of pro- and anti-inflammatory molecules and human leukocyte antigen DR (HLA-DR) expression as markers of immune status for the final outcome of septic patients. The study included 30 patients with severe sepsis due to community-acquired infections. Concentrations of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), IL-8, IL-10, and transforming growth factor beta1 (TGF-beta1) in serum, as well as monocyte HLA-DR expression, were determined on admission and on days 3, 10, 13, and 17 during hospitalization. Of the 30 patients enrolled, 13 survived, while 17 died during their hospital stay. All patients had significantly lower HLA-DR expression and higher pro- and anti-inflammatory cytokine levels than healthy individuals. HLA-DR expression was significantly decreased in nonsurvivors at almost all time points. In nonsurvivors, higher levels in serum of TNF-alpha on days 13 and 17; IL-6 levels on day 3; and IL-10 on days 3, 10, and 13 were found. Baseline levels of TGF-beta1 were significantly higher in survivors. Independent risk factors of mortality were IL-10 levels on days 3 and 10, while monocyte HLA-DR expression on admission was a good predictor for survival. Several pro- and anti-inflammatory cytokines are oversynthesized during severe infections, especially in patients with a poor outcome. Monocyte HLA-DR expression is an early and constant predictive marker for survival in severe sepsis, while serum IL-10 levels on days 3 and 10 have negative prognostic value for the final outcome.