Clinical and analytical variables associated with the development of ARDS were: patients living in an endemic area (OR 2.46; CI 95% 1.02–5.95); respiratory rate >30 bpm (OR 2.87; CI 95% 1.00–8.24); albumin <3g/dL (OR4; CI95% 1.51–10.58); C-reactive protein >100mg/L (OR 3.63; CI95% 0.98–13.39); platelet count <50x109/L (OR 2.98; CI95% 1.13–7.84); need for supplemental oxygen with a FiO2≥35% (OR 3.97; CI95% 1.25–12.60) and systolic arterial pressure (SAP) <90 mmHg (OR 6.26; CI95% 1.48–26.37). This evidence concerns the gene CRP and acute respiratory distress syndrome.