Purpose
Our objective was to revise the definition of acute respiratory distress syndrome (ARDS) using a conceptual model incorporating reliability and validity, and a novel iterative approach with ...formal evaluation of the definition.
Methods
The European Society of Intensive Care Medicine identified three chairs with broad expertise in ARDS who selected the participants and created the agenda. After 2 days of consensus discussions a draft definition was developed, which then underwent empiric evaluation followed by consensus revision.
Results
The Berlin Definition of ARDS maintains a link to prior definitions with diagnostic criteria of timing, chest imaging, origin of edema, and hypoxemia. Patients may have ARDS if the onset is within 1 week of a known clinical insult or new/worsening respiratory symptoms. For the bilateral opacities on chest radiograph criterion, a reference set of chest radiographs has been developed to enhance inter-observer reliability. The pulmonary artery wedge pressure criterion for hydrostatic edema was removed, and illustrative vignettes were created to guide judgments about the primary cause of respiratory failure. If no risk factor for ARDS is apparent, however, objective evaluation (e.g., echocardiography) is required to help rule out hydrostatic edema. A minimum level of positive end-expiratory pressure and mutually exclusive PaO
2
/FiO
2
thresholds were chosen for the different levels of ARDS severity (mild, moderate, severe) to better categorize patients with different outcomes and potential responses to therapy.
Conclusions
This panel addressed some of the limitations of the prior ARDS definition by incorporating current data, physiologic concepts, and clinical trials results to develop the Berlin definition, which should facilitate case recognition and better match treatment options to severity in both research trials and clinical practice.
Background An update of evidence-based guidelines concerning liberation from mechanical ventilation is needed as new evidence has become available. The American College of Chest Physicians (CHEST) ...and the American Thoracic Society (ATS) have collaborated to provide recommendations to clinicians concerning liberation from the ventilator. Methods Comprehensive evidence syntheses, including meta-analyses, were performed to summarize all available evidence relevant to the guideline panel’s questions. The evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, and the results were summarized in evidence profiles. The evidence syntheses were discussed and recommendations developed and approved by a multidisciplinary committee of experts in mechanical ventilation. Results Recommendations for three population, intervention, comparator, outcome (PICO) questions concerning ventilator liberation are presented in this document. The guideline panel considered the balance of desirable (benefits) and undesirable (burdens, adverse effects, costs) consequences, quality of evidence, feasibility, and acceptability of various interventions with respect to the selected questions. Conditional (weak) recommendations were made to use inspiratory pressure augmentation in the initial spontaneous breathing trial (SBT) and to use protocols to minimize sedation for patients ventilated for more than 24 h. A strong recommendation was made to use preventive noninvasive ventilation (NIV) for high-risk patients ventilated for more than 24 h immediately after extubation to improve selected outcomes. The recommendations were limited by the quality of the available evidence. Conclusions The guideline panel provided recommendations for inspiratory pressure augmentation during an initial SBT, protocols minimizing sedation, and preventative NIV, in relation to ventilator liberation.
A new classification of patients based on the duration of liberation of mechanical ventilation has been proposed.
To analyze outcomes based on the new weaning classification in a cohort of ...mechanically ventilated patients.
Secondary analysis included 2,714 patients who were weaned and underwent scheduled extubation from a cohort of 4,968 adult patients mechanically ventilated for more than 12 hours.
Patients were classified according to a new weaning classification: 1,502 patients (55%) as simple weaning,1,058 patients (39%) as difficult weaning, and 154 (6%) as prolonged weaning.Variables associated with prolonged weaning(.7d)were: severity at admission (odds ratio OR per unit of Simplified Acute Physiology Score II, 1.01; 95% confidence interval CI, 1.001–1.02), duration of mechanical ventilation before first attempt of weaning (OR per day, 1.10; 95% CI, 1.06–1.13), chronic pulmonary disease other than chronic obstructive pulmonary disease (OR,13.23; 95% CI, 3.44–51.05), pneumonia as the reason to start mechanical ventilation (OR, 1.82; 95% CI, 1.07–3.08), and level of positive end-expiratory pressure applied before weaning (OR per unit,1.09; 95% CI, 1.04–1.14). The prolonged weaning group had a nonsignificant trend toward a higher rate of reintubation (P ¼ 0.08),tracheostomy (P ¼ 0.15), and significantly longer length of stay and higher mortality in the intensive care unit (OR for death, 1.97;95%CI, 1.17–3.31). The adjusted probability of death remained constant until Day 7, at which point it increased to 12.1%.
Purpose
To improve the outcome of the acute respiratory distress syndrome (ARDS), one needs to identify potentially modifiable factors associated with mortality.
Methods
The large observational study ...to understand the global impact of severe acute respiratory failure (LUNG SAFE) was an international, multicenter, prospective cohort study of patients with severe respiratory failure, conducted in the winter of 2014 in a convenience sample of 459 ICUs from 50 countries across five continents. A pre-specified secondary aim was to examine the factors associated with outcome. Analyses were restricted to patients (93.1 %) fulfilling ARDS criteria on day 1–2 who received invasive mechanical ventilation.
Results
2377 patients were included in the analysis. Potentially modifiable factors associated with increased hospital mortality in multivariable analyses include lower PEEP, higher peak inspiratory, plateau, and driving pressures, and increased respiratory rate. The impact of tidal volume on outcome was unclear. Having fewer ICU beds was also associated with higher hospital mortality. Non-modifiable factors associated with worsened outcome from ARDS included older age, active neoplasm, hematologic neoplasm, and chronic liver failure. Severity of illness indices including lower pH, lower PaO
2
/FiO
2
ratio, and higher non-pulmonary SOFA score were associated with poorer outcome. Of the 578 (24.3 %) patients with a limitation of life-sustaining therapies or measures decision, 498 (86.0 %) died in hospital. Factors associated with increased likelihood of limitation of life-sustaining therapies or measures decision included older age, immunosuppression, neoplasia, lower pH and increased non-pulmonary SOFA scores.
Conclusions
Higher PEEP, lower peak, plateau, and driving pressures, and lower respiratory rate are associated with improved survival from ARDS.
Trial Registration: ClinicalTrials.gov NCT02010073.
Interventions that lead to earlier liberation from mechanical ventilation can improve patient outcomes. This guideline, a collaborative effort between the American Thoracic Society and the American ...College of Chest Physicians, provides evidence-based recommendations to optimize liberation from mechanical ventilation in critically ill adults.
Two methodologists performed evidence syntheses to summarize available evidence relevant to key questions about liberation from mechanical ventilation. The methodologists appraised the certainty in the evidence (i.e., the quality of evidence) using the Grading of Recommendations, Assessment, Development, and Evaluation approach and summarized the results in evidence profiles. The guideline panel then formulated recommendations after considering the balance of desirable consequences (benefits) versus undesirable consequences (burdens, adverse effects, and costs), the certainty in the evidence, and the feasibility and acceptability of various interventions. Recommendations were rated as strong or conditional.
The guideline panel made four conditional recommendations related to rehabilitation protocols, ventilator liberation protocols, and cuff leak tests. The recommendations were for acutely hospitalized adults mechanically ventilated for more than 24 hours to receive protocolized rehabilitation directed toward early mobilization, be managed with a ventilator liberation protocol, be assessed with a cuff leak test if they meet extubation criteria but are deemed high risk for postextubation stridor, and be administered systemic steroids for at least 4 hours before extubation if they fail the cuff leak test.
The American Thoracic Society/American College of Chest Physicians recommendations are intended to support healthcare professionals in their decisions related to liberating critically ill adults from mechanical ventilation.
Withdrawal from mechanical ventilation (or weaning) is one of the most common procedures in intensive care units. Almost 20 years ago, we published one of the seminal papers on weaning in which we ...showed that the best method for withdrawal from mechanical ventilation in difficult-to-wean patients was a once-daily spontaneous breathing trial with a T-piece. Progress has not stood still, and in the intervening years up to the present several other studies, by our group and others, have shaped weaning into an evidence-based technique. The results of these studies have been applied progressively to routine clinical practice. Currently, withdrawal from mechanical ventilation can be summarized as the evaluation of extubation readiness based on the patient’s performance during a spontaneous breathing trial. This trial can be performed with a T-piece, which is the most common approach, or with continuous positive airway pressure or low levels of pressure support. Most patients can be disconnected after passing the first spontaneous breathing trial. In patients who fail the first attempt at withdrawal, the use of a once-daily spontaneous breathing trial or a gradual reduction in pressure support are the preferred weaning methods. However, new applications of standard techniques, such as noninvasive positive pressure ventilation, or new methods of mechanical ventilation, such as automatic tube compensation, automated closed-loop systems, and automated knowledge-based weaning systems, can play a role in the management of the patients with difficult or prolonged weaning.
A revised definition of clinical criteria for acute respiratory distress syndrome (ARDS), the Berlin definition, was recently established to classify patients according to their severity.
To evaluate ...the accuracy of these clinical criteria using diffuse alveolar damage (DAD) at autopsy as the reference standard.
All patients who died and had a clinical autopsy in our intensive care unit over a 20-year period (1991-2010) were included. Patients with clinical criteria for ARDS were identified from the medical charts and were classified as mild, moderate, or severe according to the Berlin definition using PaO2/FiO2 oxygenation criteria. Microscopic analysis from each pulmonary lobe was performed by two pathologists.
Among 712 autopsies analyzed, 356 patients had clinical criteria for ARDS at time of death, classified as mild (n = 49, 14%), moderate (n = 141, 40%), and severe (n = 166, 46%). Sensitivity was 89% and specificity 63% to identify ARDS using the Berlin definition. DAD was found in 159 of 356 (45%) patients with clinical criteria for ARDS (in 12, 40, and 58% of patients with mild, moderate, and severe ARDS, respectively). DAD was more frequent in patients who met clinical criteria for ARDS during more than 72 hours and was found in 69% of those with severe ARDS for 72 hours or longer.
Histopathological findings were correlated to severity and duration of ARDS. Using clinical criteria the revised Berlin definition for ARDS allowed the identification of severe ARDS of more than 72 hours as a homogeneous group of patients characterized by a high proportion of DAD.
Summary
Background
: Although subclinical enthesopathy is a well‐established diagnostic criterion for psoriatic arthritis (PsA), it is frequently overlooked, as many patients are asymptomatic. The ...possibility of finding a clinical clue predicting enthesopathy would help clinicians establish an early diagnosis of PsA.
Material and methods
: A prospective single‐center study of a total of 90 patients with psoriasis was conducted to assess the presence of entheseal abnormalities as detected by ultrasound, and to determine any correlation with nail involvement.
Results
: Entheseal abnormalities were found in 23 patients (25.5 %), 19 (82.6 %) of whom showed nail involvement, whereas four (17.4 %) individuals did not. Enthesopathy was present in 31.1 % (19/61) of patients with onychopathy compared to 13.8 % (4/29) of those without nail involvement (p = 0.07). There was a significant correlation between target NAPSI score and evidence of enthesopathy. In addition, the number of nails affected also showed a significant correlation with the presence of enthesopathy (p = 0.035).
Conclusions
: Clinical evidence of onychopathy may be the clue to an early diagnosis of enthesopathy in psoriasis patients.
The acute respiratory distress syndrome (ARDS) is characterized by protein-rich oedema in the alveolar spaces, a feature in which Fas-mediated apoptosis of the alveolar epithelium has been involved.
...To determine whether Fas activation increases protein permeability by mechanisms involving disruption of the paracellular tight junction (TJ) proteins in the pulmonary alveoli.
Protein permeability and the expression of TJ proteins were assessed in vivo in wild-type and Fas-deficient lpr mice 16 hours after the intratracheal instillation of recombinant human soluble Fas ligand (rh-sFasL), and at different time points in vitro in human pulmonary alveolar epithelial cells (HPAEpiC) exposed to rh-sFasL
Activation of the Fas pathway increased protein permeability in mouse lungs and altered the expression of the TJ proteins occludin and zonula occludens-1 in the alveolar-capillary membrane in vivo and in human alveolar epithelial cell monolayers in vitro. Blockade of caspase-3, but not inhibition of tyrosine kinase dependent pathways, prevented the alterations in TJ protein expression and permeability induced by the Fas/FasL system in human alveolar cell monolayers in vitro. We also observed that both the Fas-induced increase of protein permeability and disruption of TJ proteins occurred before cell death could be detected in the cell monolayers in vitro.
Targeting caspase pathways could prevent the disruption of TJs and reduce the formation of lung oedema in the early stages of ARDS.
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