Adult patients aged >18<65 years, hypercapnia with PH <7.25, hypoxic index less than 200 (PaO2/FIO2), bilateral parenchymatous lung infiltration in the chest Xray. All selected patients received conventional ventilation with protective lung strategy for 3 days with Controlled mechanical ventilation mode (CMV), fraction inspired oxygen (FIO2) of 100%, Positive end expiratory pressure (PEEP) adjusted to achieve target arterial oxygen saturation (SPO2) of >90%. Sedation and pain control done by both midazolam and fentanyl infusion to achieve Richmond Agitation- Sedation Scale (RASS) -2. Protective lung strategy applied and include, head elevation more than 45-degree, daily assessment for both analgesic and sedative dose, early naso-gastric feeding to prevent bacterial translocation and flooding of the blood with gram negative septicemia, usage of the minimal PEEP to maintain SPO2 >90%. Qualitative sputum culture was taken after 3 days from ventilation. After 3 days from the conventional ventilation only 240 patients enrolled in our study. Those who had a Murray score (for diagnosis of ARDS) of >3 and CPIS (clinical pulmonary infection score) (for diagnosis of VAP) > 6. All patients were randomly allocated in 2 groups 120 patients in each. All patients received intravenous antibiotics meropenem 1 gm slowly intravenous every 8 hours for the first 8 days then antibiotics was given according to sputum culture and antibiotics sensitivity. Group A received high dose (30 mg/kg) methylprednisolone slowly intravenous in 250 ml normal saline every 8 hours for only 4 days while group B included received 1 mg/kg/day methylprednisolone divided to three doses given every 8 hours for two weeks. This study conducted for 16 days.~VAP diagnosed in our study by CPIS 6 or more while severity of lung contusion assessed by Murray score 3 or more
patients who had >3 on Murray score and >6 on CPIS allocated randomly in two groups 120 patients in each. Group A received 30 mg/kg methyl-prednisolone slowly intravenous in 250 mL normal saline every 8 hours for only 48 hours while group B received 1 mg/kg/day methyl-prednisolone divided to three doses given every 8 hours for two weeks. Duration of the study last 16 days, Morbidity considered if no improvement in any or all clinical parameters of both Murray and CPIS scores and failure of weaning of patients from the ventilator at the studied period.