Redefining ARDS: a paradigm shift

Abstract

Although the defining elements of "acute respiratory distress syndrome" (ARDS) have been known for over a century, the syndrome was first described in 1967. Since then, despite several revisions of its conceptual definition, it remains a matter of debate whether ARDS is a discrete nosological entity. After almost 60 years, it is appropriate to examine how critical care has modeled this fascinating syndrome and affected patient's outcome. Given that the diagnostic criteria of ARDS (e.g., increased pulmonary vascular permeability and diffuse alveolar damage) are difficult to ascertain in clinical practice, we believe that a step forward would be to standardize the assessment of pulmonary and extrapulmonary involvement in ARDS to ensure that each patient can receive the most appropriate and effective treatment. The selection of treatments based on arbitrary ranges of PaO₂/FiO₂ lacks sufficient sensitivity to individualize patient care.

Keywords: Acute hypoxemic respiratory failure; Acute respiratory distress syndrome; Clinical trials; Definitions; Mechanical ventilation; Prognosis; Standardization; Stratification.

Fig. 1

The acute respiratory distress syndrome (ARDS) high-speed train showing variables and factors affecting definition and outcome of patients with ARDS. Abbreviations: ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; LPV, lung protective ventilation; MV, mechanical ventilation; PEEP, positive end-expiratory pressure; P/F, PaO₂/FiO₂ ratio; RCT, randomized controlled trials; SOFA, sequential organ function assessment; SVS, standardized ventilator settings; VD/VT, alveolar dead space; VT, tidal volume