American-European Consensus Conference Research Articles

ARDS (Acute Respiratory Distress Syndrome) in Pediatric and Adult

Acute Respiratory Distress Syndrome (ARDS) is a serious medical condition that occurs when lungs become severely inflamed, which inhibits the ability to take in the oxygen and eliminate carbon dioxide. The purpose of this article is to find out more about the clinical manifestation, pathophysiology, diagnosis, and treatment of ARDS. The literatures that used for this literature review are from National Center for Biotechnology Information (NCBI), Google scholar, and Proquest. The result for this literature review is the development of ARDS is associated with inflammation in lung’s epithelium, endothelium, and interstitium which consist three phases which is exudative, proliferative, and fibrotic phases. The Berlin Criteria issued by the American-European Consensus Conference (AECC) in 2021 used for ARDS diagnosis. The treatments for ARDS could used pharmacotherapy and non-pharmacotherapy.

Development of acute lung injury or acute respiratory distress syndrome after subarachnoid hemorrhage, predictive factors, and impact on prognosis

Acute lung injury or acute respiratory distress syndrome (ALI/ARDS) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH), and is associated with worse neurologic outcomes and longer hospitalization. However, the effect of ALI/ARDS in SAH has not been well elucidated. The purpose of this study was to determine the incidence of ALI/ARDS in a cohort of patients with SAH and to determine the risk factors for ALI/ARDS and their impact on patient prognosis. We performed a retrospective analysis of 167 consecutive patients with aSAH enrolled. ALI/ARDS patients were rigorously adjudicated using North American-European Consensus Conference definition. Regression analyses were used to test the risk factors for ALI/ARDS in patients with SAH. A total of 167 patients fulfilled the inclusion criteria, and 27% patients (45 of 167) developed ALI. Among all 45 ALI patients, 33 (20%, 33 of 167) patients met criteria for ARDS. On multivariate analysis, elderly patients, lower glasgow coma scale (GCS), higher Hunt-Hess grade, higher simplified acute physiology score (SAPS) II score, pre-existing pneumonia, gastric aspiration, hypoxemia, and tachypnea were the strongest risk factor for ALI/ARDS. Patients with ALI/ARDS showed worse clinical outcomes measured at 30 days. Development of ALI/ARDS was associated with a statistically significant increasing the odds of tracheostomy and hospital complications, and increasing duration of mechanical ventilation, intensive care unit (ICU) length and hospitalization stay. Development of ALI/ARDS is a severe complication of SAH and is associated with a poor clinical outcome, and further studies should focus on both prevention and management strategies specific to SAH-associated ALI/ARDS.

Newly Proposed Diagnostic Criteria for Acute Respiratory Distress Syndrome: Does Inclusion of High Flow Nasal Cannula Solve the Problem?

Acute respiratory distress syndrome (ARDS) is a common life-threatening clinical syndrome which accounts for 10% of intensive care unit admissions. Since the Berlin definition was developed, the clinical diagnosis and therapy have changed dramatically by adding a minimum positive end-expiratory pressure (PEEP) to the assessment of hypoxemia compared to the American-European Consensus Conference (AECC) definition in 1994. High-flow nasal cannulas (HFNC) have become widely used as an effective respiratory support for hypoxemia to the extent that their use was proposed in the expansion of the ARDS criteria. However, there would be problems if the diagnosis of a specific disease or clinical syndrome occurred, based on therapeutic strategies.

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

Indeterminate randomized controlled trials (RCTs) in ARDS may arise from sample size misspecification, leading to abandonment of efficacious therapies. 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? 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. 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 was predicted in 21 of 28 RCTs (75.0%). 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. 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.

Metabolomic diferences between COVID-19 and H1N1 influenza induced ARDS

BackgroundAcute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by lung inflammation and pulmonary edema. Coronavirus disease 2019 (COVID-19) is associated with ARDS in the more severe cases. This study aimed to compare the specificity of the metabolic alterations induced by COVID-19 or Influenza A pneumonia (IAP) in ARDS.MethodsEighteen patients with ARDS due to COVID-19 and twenty patients with ARDS due to IAP, admitted to the intensive care unit. ARDS was defined as in the American-European Consensus Conference. As compared with patients with COVID-19, patients with IAP were younger and received more often noradrenaline to maintain a mean arterial pressure > 65 mm Hg. Serum samples were analyzed by Nuclear Magnetic Resonance Spectroscopy. Multivariate Statistical Analyses were used to identify metabolic differences between groups. Metabolic pathway analysis was performed to identify the most relevant pathways involved in ARDS development.ResultsARDS due to COVID-19 or to IAP induces a different regulation of amino acids metabolism, lipid metabolism, glycolysis, and anaplerotic metabolism. COVID‐19 causes a significant energy supply deficit that induces supplementary energy-generating pathways. In contrast, IAP patients suffer more marked inflammatory and oxidative stress responses. The classificatory model discriminated against the cause of pneumonia with a success rate of 100%.ConclusionsOur findings support the concept that ARDS is associated with a characteristic metabolomic profile that may discriminate patients with ARDS of different etiologies, being a potential biomarker for the diagnosis, prognosis, and management of this condition.Graphical

Prognostic factors for development of acute respiratory distress syndrome following traumatic injury: a systematic review and meta-analysis.

Our purpose was to summarise the prognostic associations between various clinical risk factors and development of acute respiratory distress syndrome (ARDS) following traumatic injury. We conducted this review in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and CHARMS (Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies) guidelines. We searched six databases from inception through December 2020. We included English language studies describing the clinical risk factors associated with development of post-traumatic ARDS, as defined by either the American-European Consensus Conference or Berlin definition. We pooled adjusted odds ratios for prognostic factors using the random effects method. We assessed risk of bias using the QUIPS (Quality in Prognosis Studies) tool and certainty of findings using GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. We included 39 studies involving 5 350 927 patients. We identified the amount of crystalloid resuscitation as a potentially modifiable prognostic factor associated with development of post-traumatic ARDS (adjusted OR 1.19, 95% CI 1.15-1.24 for each additional litre of crystalloid administered within the first 6 h after injury; high certainty). Non-modifiable prognostic factors with a moderate or high certainty of association with post-traumatic ARDS included increasing age, non-Hispanic White race, blunt mechanism of injury, presence of head injury, pulmonary contusion or rib fracture and increasing chest injury severity. We identified one important modifiable factor, the amount of crystalloid resuscitation within the first 24 h of injury, and several non-modifiable factors associated with development of post-traumatic ARDS. This information should support the judicious use of crystalloid resuscitation in trauma patients and may inform development of risk stratification tools.

Performance of acute respiratory distress syndrome definitions in a high acuity paediatric intensive care unit

BackgroundFor years, paediatric critical care practitioners used the adult American European Consensus Conference (AECC) and revised Berlin Definition (BD) for acute respiratory distress syndrome (ARDS) to study the epidemiology of paediatric ARDS (PARDS). In 2015, the paediatric specific definition, Paediatric Acute Lung Injury Consensus Conference (PALICC) was developed. The use of non-invasive metrics of oxygenation to stratify disease severity were introduced in this definition, although this potentially may lead to a confounding effect of disease severity since it is more common to place indwelling arterial lines in sicker patients. We tested the hypothesis that PALICC outperforms AECC/BD in our high acuity PICU, which employs a liberal use of indwelling arterial lines and high-frequency oscillatory ventilation (HFOV).MethodsWe retrospectively collected data from children < 18 years mechanically ventilated for at least 24 h in our tertiary care, university-affiliated paediatric intensive care unit. The primary endpoint was the difference in the number of PARDS cases between AECC/BD and PALICC. Secondary endpoints included mortality and ventilator free days. Performance was assessed by the area under the receiver operating characteristics curve (AUC-ROC).ResultsData from 909 out of 2433 patients was eligible for analysis. AECC/BD identified 35 (1.4%) patients (mortality 25.7%), whereas PALICC identified 135 (5.5%) patients (mortality 14.1%). All but two patients meeting AECC/Berlin criteria were also identified by PALICC. Almost half of the cohort (45.2%) had mild, 33.3% moderate and 21.5% severe PALICC PARDS at onset. Highest mortality rates were seen in patients with AECC acute lung injury (ALI)/mild Berlin and severe PALICC PARDS. The AUC-ROC for Berlin was the highest 24 h (0.392 [0.124–0.659]) after onset. PALICC showed the highest AUC-ROC at the same moment however higher than Berlin (0.531 [0.345–0.716]). Mortality rates were significantly increased in patients with bilateral consolidations (9.3% unilateral vs 26.3% bilateral, p = 0.025).ConclusionsPALICC identified more new cases PARDS than the AECC/Berlin definition. However, both PALICC and Berlin performed poorly in terms of mortality risk stratification. The presence of bilateral consolidations was associated with a higher mortality rate. Our findings may be considered in future modifications of the PALICC criteria.

To evaluate different demographical and clinical characterstics in patients suffering from ARDS/ALI

Introduction: Acute lung injury (ALI) remains a significant source of morbidity and mortality in the critically ill patient population. Defined by a constellation of clinical criteria (acute onset of bilateral pulmonary infiltrates with hypoxemia without evidence of hydrostatic pulmonary edema). Pathogenesis of ALI is explained by injury to both the vascular endothelium and alveolar epithelium. Materials and Methods : This was a prospective, observational and cross-sectional study conducted in the medical ICU of Department of Pulmonology at tertiary care teaching hospital between May 2018 and April 2019. Patients with ALI/ARDS were identified through a prospective daily ICU surveillance, based on the American-European Consensus Conference criteria (AECC). Result : In our study, we had a total of 59 patient, out of which 43 survived. We had a mortally rate of 27.2%. Most of the patients were 25-60 years i.e., 23 out of 43, followed by Conclusions: Pneumonia and tropical diseases are the common risk factor for the ARDS/ALI. The presence of co-morbid conditions also affects the outcome of ALI/ARDS patients. MODS of >4, LIs >2 and APACHE II >2 had associated with higher mortality. Keywords: Acute respiratory distress syndrome (ARDS), Pulmonary edema, Acute respiratory failure.

Acute lung injury - from pathophysiology to treatment.

Acute lung injury is characterized by acute respiratory insufficiency with tachypnea, cyanosis refractory to oxygen, decreased lung compliance, and diffuse alveolar infiltrates on chest X-ray. The 1994 American-European Consensus Conference defined "acute respiratory distress syndrome, ARDS" by acute onset after a known trigger, severe hypoxemia defined by PaO2/FiO2</=200 mm Hg, bilateral infiltrates on chest X-ray, and absence of cardiogenic edema. Milder form of the syndrome with PaO2/FiO2 between 200-300 mm Hg was named "acute lung injury, ALI". Berlin Classification in 2012 defined three categories of ARDS according to hypoxemia (mild, moderate, and severe), and the term "acute lung injury" was assigned for general description or for animal models. ALI/ARDS can originate from direct lung triggers such as pneumonia or aspiration, or from extrapulmonary reasons such as sepsis or trauma. Despite growing understanding the ARDS pathophysiology, efficacy of standard treatments, such as lung protective ventilation, prone positioning, and neuromuscular blockers, is often limited. However, there is an increasing evidence that direct and indirect forms of ARDS may differ not only in the manifestations of alterations, but also in the response to treatment. Thus, individualized treatment according to ARDS subtypes may enhance the efficacy of given treatment and improve the survival of patients.

Diffuse Alveolar Damage Correlation with Clinical Diagnosis of Pediatric Acute Respiratory Distress Syndrome.

Diffuse alveolar damage (DAD) is one of the pathological hallmarks of acute respiratory distress syndrome (ARDS). We aimed to compare pathological findings of DAD with clinical ARDS criteria. We re-evaluated 20 patients whose clinical autopsy revealed DAD. Total 11/20 patients with DAD (55%) met the 1994 American-European Consensus Conference and 7/17 (41%) met the 2012 Berlin clinical criteria. DAD showed only moderate correlation with current clinical ARDS definition. Oxygenation index (OI), seems to be the most valuable tool in predicting pulmonary damage severity, though OI is not listed in either of the previous definitions. We support the recommended use of OI by 2015 consensus conference.

Mortality of Adult Respiratory Distress Syndrome in Trauma Patients: A Systematic Review over a Period of Four Decades.

Acute respiratory distress syndrome (ARDS) is associated with high morbidity and mortality. In addition, its aetiologies are heterogeneous, and the outcome depends on the underlying cause. In trauma care, changes in diagnostics, management and treatment may influence the outcome of posttraumatic ARDS over time, which are attributable to geographic distribution, relate to the definition used and depend on the injury severity. We selected studies by searching PubMed using the MeSH terms "acute respiratory distress syndrome", "mortality" and "trauma" and all their combinations. Studies that reported mortality rates for polytrauma patients with ARDS were included. We excluded studies with selected population collectives (e.g. burn patients, isolated thoracic trauma and paediatric trauma) and non-trauma studies. Studies were stratified according to the recruitment year of patients into Decade 1 (prior 1990), Decade 2(1990-1999), Decade 3 (2000-2009) and Decade 4 (later 2009); geographic location (North America or Europe), the definition used in the different studies (American European Consensus Conference (AECC) definition or Berlin definition) and the mean injury severity of the patient populations, respectively. Twenty-three studies between 1 January 1980 and 30 June 2018 were included in the analysis (486,861 patients, 52,561 with posttraumatic ARDS). There was a wide variation in mortality rates among the studies (4-39%). The overall pooled mean mortality rate for all studies was 21.8%, SD ± 8.3%. The mean mortality over the last four decades was similar between decade 1 (25.8%), decade 2 (20.6%), decade 3 (20.7%) and decade 4 (22.5%). Geographical observations comparing Europe and North America revealed no difference [Europe (22.1%) and North America (21.7%)]. The ARDS mortality in publications using the Berlin definition (23%) was comparable to the mortality rate in publications using the AECC definition (22.9%). The mortality rate based on the injury severity showed no alteration (ISS ≤ 25 points, 22.6%, ISS > 25 points, 22.6%). In this systematic review, there was no change in the mortality rate over the last four decades, no geographical difference within Western societies, no dependence on the ARDS definition used and no association with injury severity, respectively.

ARDS DUE LEGIONELLA MICDADEI CAVITARY PNEUMONIA

SESSION TITLE: Wednesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Legionella has over 50 recognized species, some of which have been reported in the literature to cause severe pneumonias. We present a case of severe cavitary pneumonia leading to ARDS caused by Legionella micdadei in an immunocompromised patient. CASE PRESENTATION: A 75 year old man with past medical history of recurrent prostate cancer with metastases to cervical spine on bicalutamide and dexamethasone, presented for fevers and respiratory distress. Initial labs showed sodium 132, leukocytosis 27, lactate 7, Procalcitonin 1.88, and arterial blood gas with pH 7.5, CO2 24, PO2 82. CT chest showed extensive bilateral lower lobe dependent consolidation and multiple bilateral nodular infiltrates. Shortly after admission to the MICU the patient went in to shock requiring intubation and mechanical ventilation with vasopressors. Started cisatricurium, high PEEP strategy, up to 17, and 100% Fio2 on PRVC, as well as, administration of inhaled nitric oxide, but was unable to maintain oxygen saturations and required RotoProne. Patient underwent 48 hour proning protocol with improvement in his P:F ratio after 24 hours. On MICU day 7 legionella culture returned positive for Legionella micdadei. DISCUSSION: Legionella micdadei is the second most common legionella species, accounting for approximately 9% of all legionella cases [4]. L. micdadei is more commonly identified as the cause of nosocomial pneumonias, however, review of the literature reveals case reports of community acquired L. micdadei in a patient with multiple myeloma on thalidomide therapy, as well as, renal transplant recipients and patients with HIV [1]. While bicalutimide is a hormone therapy and has been reported to cause pneumonitis and interstitial lung disease, it has not been associated with opportunistic infections. Our patient was at risk most likely due to the dexamethasone [3]. Our patient may be one of the few reported cases of L. micdadei in literature that progressed to ARDS and required proning. The pronator bed conceptually allows for a more uniform distribution of lung stress and strain, which leads to improved ventilation-perfusion matching and improved lung and chest wall mechanics. We followed standard ARDSNET protocol with our patient. Rapidly increasing oxygen and PEEP requirements without improvement had prompted us to consider pronation in our patient. Our patient saw rapid improvement in his P:F ratio within 24 hours after proning, and was removed from proning after 48 hours. CONCLUSIONS: Our case not only highlights the importance of early diagnosis of atypical pneumonias in the immunocompromised patient, but also the severity of illness caused by this atypical organism. Reference #1: D. Lachant and P. Prasad, “Legionella micdadei: A Forgotten Etiology of Growing Cavitary Nodules: A Case Report and Literature Review,” Case Reports in Pulmonology, vol. 2015, 2015. Reference #2: L. P. Girard and D. B. Gregson, “Community-Acquired Lung Abscess Caused by Legionella micdadei in a Myeloma Patient Receiving Thalidomide Treatment,” Journal of Clinical Microbiology, Sept 2007, pp. 3135-3137. Reference #3: Bernard GR, Artigas A, Brigham KL, Carlet J, Falke K, Hudson L, Lamy M, Legall JR, Morris A, Spragg R. The American-European Consensus Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial coordination. Am J Respir Crit Care Med. 1994;149:818–824. DISCLOSURES: No relevant relationships by Dennis Genin, source=Web Response No relevant relationships by Asma Iftikhar, source=Web Response No relevant relationships by John Prudenti, source=Web Response no disclosure on file for Lourdes Sanso

To study different etiological and prognostic factors in patients suffering from ARDS/ALI

To study different etiological and prognostic factors in patients suffering from ARDS/ALI - IJIRM- Print ISSN No: - 2581-4214 Online ISSN No:- 2581-4222 Article DOI No:- 10.18231/j.ijirm.2019.024, IP Indian Journal of Immunology and Respiratory Medicine-IP Indian J Immunol Respir Med

A Scoring System with High-Resolution Computed Tomography to Predict Drug-Associated Acute Respiratory Distress Syndrome: Development and Internal Validation

Drugs can cause acute respiratory distress syndrome (ARDS). However, there is no established clinical prediction rule for drug-associated ARDS (DARDS). We aimed to develop and validate a scoring system for DARDS prediction. We analysed data collected from a prospective, single-centre, cohort study that included ARDS patients. The ARDS diagnosis was based on the American-European Consensus Conference or Berlin definition. Drug-associated acute lung injury (DALI) was defined as previous exposure to drugs which cause ALI and presence of traditional risk factors for ALI. High-resolution computed tomography (HRCT; indicating extent of lung damage with fibroproliferation), Acute Physiology and Chronic Health Evaluation (APACHE) II, and disseminated intravascular coagulation (DIC; indicating multiorgan failure) scores and PaO2/FiO2 were evaluated for their ability to predict DARDS. Twenty-nine of 229 patients had DARDS. The HRCT, APACHE II, and DIC scores and PaO2/FiO2 were assessed. The model-based predicted probability of DARDS fitted well with the observed data, and discrimination ability, assessed through bootstrap with an area under the receiver-operating curve, improved from 0.816 to 0.875 by adding the HRCT score. A simple clinical scoring system consisting of the APACHE II score, PaO2/FiO2, and DIC and HRCT scores can predict DARDS. This model may facilitate more appropriate clinical decision-making.

Evolution of ARDS definition and establishment of diagnostic criteria for neonatal ARDS

Acute respiratory distress syndrome(ARDS)is a common clinical critical illness and is one of the important causes of neonatal death.Since the first report of ARDS in 1967, its definition and diagnostic criteria have been controversial.The AECC diagnostic criteria proposed by American-European Consensus Conference in 1994 and the Berlin diagnostic criteria issued in 2012 are of great significance for the clinical diagnosis and scientific research of ARDS.In 2017, the first international diagnostic criteria for ARDS in neonates was released, which will play an active role in promoting basic research and clinical practice of neonatal ARDS.This article reviews the evolution of ARDS definitions and diagnostic criteria, as well as the establishment and clinical applications of diagnostic criteria for neonatal ARDS. Key words: Acute respiratory distress syndrome; Diagnostic criteria; Newborn infants

Clinical profile and survival outcome of acute respiratory distress syndrome in a rural tertiary care hospital

Background: Acute respiratory distress syndrome (ARDS) is characterized by rapid onset severe dyspnea, hypoxemia, and diffuse bilateral pulmonary infiltrates leading to respiratory failure. This syndrome can occur even without primary damage to the lung parenchyma, and thus, they are more often classified as ARDS due to pulmonary and extrapulmonary causes. Mortality estimates range from 26% to 44% in different studies. There are several critical care scores that are in vogue in intensive care units. This study was undertaken to describe the clinical profile of ARDS and along with that the study also intended to correlate the outcome of ARDS patients with reference to these critical care scores and try to establish which score would be best to prognosticate ARDS. Aims: This study aims to study the clinical profile and survival outcome of ARDS in a rural tertiary care hospital. Materials and Methods: All patients fulfilling the inclusion criteria as per the 1994 American European Consensus Conference on ARDS definition of ARDS were included in the study. The severity of ARDS was measured by various critical care scores such as the Acute Physiology and Chronic Health Evaluation Score, Multiple Organ Dysfunction Score (MODS), Lung Injury Score (LIS), and Sequential Organ Dysfunction Assessment (SOFA score). Results: The ratio of male and female (male: female) was 1.7:1.0. Proportion of males (62.5%) was significantly higher than that of females (37.5%) (Z = 3.53;P

Neuromuscular blocking agents for adult patients with acute respiratory distress syndrome: A meta-analysis of randomized controlled trials.

To explore the effect of neuromuscular blocking agents (NMBAs) on adult patients with acute respiratory distress syndrome (ARDS) by meta-analysis. Three databases including Cochrane central register of controlled trials, PubMed, and Wanfang Data were searched to find relevant articles. We included randomized controlled trials that evaluated NMBAs compared with placebo or usual treatment in adult patients with ARDS. Five trials totaling 551 patients were identified eligible for inclusion. All the five trials were protective ventilation strategies based. All patients (the ratio of partial pressure of arterial oxygen/fraction of inspired oxygen ≤ 200 mm Hg) met American-European Consensus Conference or the Berlin definition oxygenation criteria for ARDS. Neuromuscular blocking agents significantly reduced intensive care unit mortality (relative risk, 0.73; 95% confidence intervals [CI], 0.58-0.93; p = 0.009; I = 0.0%; 4 trials, 455 patients) and 21- to 28-day mortality (relative risk, 0.63; 95% CI, 0.49-0.82; p = 0.001; I = 0.0%; 4 trials, 527 patients). At 48 hours, NMBAs improved oxygenation (weighted mean differences [WMD], 27.98; 95% CI, 7.45-48.51; p = 0.008; I = 44.2%; 4 trials, 212 patients). However, NMBAs have no effect on reduction of oxygenation at 24 hours (WMD, 26.83; 95% CI, -5.89 to 59.55; p = 0.108; I = 82.4%; 4 trials, 447 patients), and plateau pressure (WMD, 0.43; 95% CI, -0.46 to 1.31; p = 0.345; 4 trials, 455 patients) as well as positive end expiratory pressure (WMD, 0.10; 95% CI, -0.47 to 0.67; p = 0.73; 4 trials, 455 patients) at 48 hours. Protective ventilation strategies based NMBAs treatment reduces mortality in patients with moderate to severe ARDS. Systematic reviews & meta-analysis, level III.

Practice of diagnosis and management of acute respiratory distress syndrome in mainland China: a cross-sectional study.

Although acute respiratory distress syndrome (ARDS) has been recognized for more than 50 years, limited information exists about the incidence and management of ARDS in mainland China. To evaluate the potential for improvement in management of patients with ARDS, this study was designed to describe the incidence and management of ARDS in mainland China. National prospective multicenter observational study over one month (August 31st to September 30th, 2012) of all patients who fulfilled the Berlin or American European Consensus Conference (AECC) definition of ARDS in 20 intensive care units, with data collection related to the management of ARDS, patient characteristics and outcomes. Of the 1,814 patients admitted during the enrollment period, 149 (8.2%) and 147 (8.1%) patients were diagnosed by AECC and Berlin definition, respectively. Lung protective strategy with low tidal volume (Vt) (≤8 mL/kg) and limitation of the plateau pressure (Pplat) (≤30 cmH2O) was performed in 75.2% patients. And, 36%, 21.1% and 4.1% patients with severe, moderate and mild ARDS had the driving pressure more than 14 cmH2O (P<0.05). Pplat and driving pressure increased significantly in patients with a higher degree of ARDS severity (P=0.002 and P<0.001, respectively), but Vt were comparable in the three groups (P>0.05). In severe ARDS, patient median positive end expiratory pressure (PEEP) was 10.0 (8.0-11.3) cmH2O and median FiO2 was 90%. A recruitment maneuver was performed in 35.5% of the patients, and 8.7% of patients with severe ARDS received prone position. Overall hospital mortality was 34.0%. Hospital mortality was 21.8% for mild, 31.1% for moderate, and 60.0% for patients with severe ARDS (P=0.004). Despite general acceptance of low Vt and limited Pplat, high driving pressure, low PEEP and low use of adjunctive measures may still be a concern in mainland China, especially in patients with severe ARDS. ClinicalTrials.gov NCT01666834; date of registration release: August 14th 2012.

Recent advances in understanding and treating acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is a clinically and biologically heterogeneous disorder associated with many disease processes that injure the lung, culminating in increased non-hydrostatic extravascular lung water, reduced compliance, and severe hypoxemia. Despite enhanced understanding of molecular mechanisms, advances in ventilatory strategies, and general care of the critically ill patient, mortality remains unacceptably high. The Berlin definition of ARDS has now replaced the American-European Consensus Conference definition. The recently concluded Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG-SAFE) provided worldwide epidemiological data of ARDS including prevalence, geographic variability, mortality, and patterns of mechanical ventilation use. Failure of clinical therapeutic trials prompted the investigation and subsequent discovery of two distinct phenotypes of ARDS (hyper-inflammatory and hypo-inflammatory) that have different biomarker profiles and clinical courses and respond differently to the random application of positive end expiratory pressure (PEEP) and fluid management strategies. Low tidal volume ventilation remains the predominant mainstay of the ventilatory strategy in ARDS. High-frequency oscillatory ventilation, application of recruitment maneuvers, higher PEEP, extracorporeal membrane oxygenation, and alternate modes of mechanical ventilation have failed to show benefit. Similarly, most pharmacological therapies including keratinocyte growth factor, beta-2 agonists, and aspirin did not improve outcomes. Prone positioning and early neuromuscular blockade have demonstrated mortality benefit, and clinical guidelines now recommend their use. Current ongoing trials include the use of mesenchymal stem cells, vitamin C, re-evaluation of neuromuscular blockade, and extracorporeal carbon dioxide removal. In this article, we describe advances in the diagnosis, epidemiology, and treatment of ARDS over the past decade.

Study of etiology and scoring system in acute lung injury and acute respiratory distress syndrome patients

Background: The acute respiratory distress syndrome (ARDS) is a clinical disorder characterized by injury to the alveolar epithelium and endothelial barriers of the lung, acute inflammation, and protein rich pulmonary edema leading to respiratory failure. Present study was carried out to investigate the mortality pattern of ALI/ARDS in the patients and to study the etiological factors leading to ALI/ARDS also to study the clinical pattern in patients with ALI/ARDS.Methods: All patients fulfilling the inclusion criteria as per the 1994 American European Consensus Conference on ARDS/ALI definition of ARDS/ALI were included in the study. On clinical examination the vital parameters were recorded. The respiratory system, abdominal, cardiovascular and central nervous systems were examined in detail. The severity of the illness was measured by the acute physiology and Chronic Health Evaluation (APACHE) Score, Multiple Organ Dysfunction score (MODS), lung injury score (LIS) and Sequential Organ Dysfunction Assessment (SOFA score). These scores were calculated on admission to our intensive care unit.Results: Out of the 65 patients 35 survived and 30 died. A multiple organ dysfunction Score of less than or equal to 4 was seen in 29 patients and more than 4 in 36 patient and a score of less than or equal to 4 was seen in 21 survivors and 8 dead patients, while a score of more than four was found in 14 patients who survived versus 22 patients who died. A lung injury score of less than or equal to 2 was seen in patients and more than 2 in 46 patients and a score of less than or equal to 2 was seen in 14 survivors and 5 non-survivors patients, while a score of more than 2 was found in 21 patients who survived versus 25 patients who died.Conclusions: The commonest etiological conditions leading to ALI/ARDS are pneumonia and tropical diseases including malaria, leptospirosis and dengue. The scoring systems, MODS, LIS and APACHE II are good indicators of the outcome of this condition. They are useful in tropical diseases as well.