Although the AECC definition has had the merit of formalizing the diagnostic criteria for ARDS and is simple to use in daily practice, it has been questioned over the years in light

of the increased knowledge on the disease.20 and 21 The limitations can be grouped regarding a few factors: 1) Heterogeneity: The AECC definition GSK1210151A supplier transforms multiple physiopathological processes and groups of very different patients into a single syndrome. 22 The triggering mechanism of lung injury, 23, 24 and 25 the phase of the disease 26, and the time of onset of pulmonary mechanical ventilation (PMV) greatly contribute to the question of heterogeneity. 27 and 28 The practical implications of these problems are obvious, as a therapy administered to a group of patients with positive results may not have the same effect in another. As there was no agreement between the definitions developed to date, Ferguson et al.,44 and 45 in 2005, developed another clinical definition of ARDS, using

the Delphi technique. This definition incorporated additional variables, such as SB431542 mouse the level of PEEP (PaO2/FiO2 ≤ 200 with PEEP ≥ 10 cm H2O); a precise definition of acute onset (within 72 hours); a subjective assessment of cardiac involvement (without clinical evidence of congestive heart failure); an objective assessment of cardiac involvement (PCP ≤ 18 mmHg or ejection Paclitaxel fraction ≥ 40%); assessment of pulmonary compliance (static compliance < 50 cm H2O, with tidal volume of 8 mL/kg); and quantification of radiological criteria for the disease in two or more quadrants. Although it apparently solved the problems of the previous definitions, the same researchers reported that, although the Delphi definition is more specific than the AECC criterion, it was less sensitive when autopsy findings of diffuse alveolar damage were chosen as the gold standard for the diagnosis

of ARDS.46 Esteban et al.,47 in 2004, performed a retrospective study to compare autopsy findings and clinical features of adults with a clinical diagnosis of ARDS, and found that the accuracy of AECC was only moderate (75% sensitivity and 84% specificity), working better in patients with extrapulmonary risk factors. The concordance between the AECC and Murray score was also studied, and was shown to be moderate.48 Moreover, three studies showed varying degrees of concordance between AECC and the ALI score.46, 48 and 49 In a study initiated in 2010, several members of the European Society of Intensive Care Medicine selected other professionals from Europe and the United States with the objective of reviewing the definition of ARDS.50 The discussion panel emphasized the applicability, reliability, validity (how physicians recognize the disease), and predictive capacity (capacity to predict response to treatment, prognosis, or both) of a new definition.