UPDATE IN INTENSIVE CARE: MECHANICAL VENTILATION Strategies against refractory hypoxemia in acute respiratory distress syndrome

Refractory hypoxemia is an extremely complex condition with a high morbidity-mortality rate. This clinical situation represents an advanced process encompassed within the so-called acute respiratory distress syndrome (ARDS), defined by the American-European Conference of 1994 with the purpose of reaching consensus on a series of homogeneous criteria. Acute respiratory failure (ARF) is defined on the basis of clinical, radiological and blood gas parameters. Acute lung injury (ALI) in turn is defined as a PaO2/FiO2 ratio of under 300 mmHg, and in ARDS it is taken to represent a ratio of under 200 mmHg. Recently, in the year 2011, experts gathered in Berlin and redefined the classification (the ‘‘Berlin definition’’), improving stratification and mortality prediction of the syndrome, but without clarifying