This study would consist of 170 burn patients with documented smoke inhalation injury who will be randomized to receive either standard care alone (control group) or standard care plus heparin nebulization in combination with intravenously administrated fresh frozen plasma (study group). Standard care treatment consist of: chest physiotherapy ,early ambulation, airway suctioning, bronchial hygiene therapy , salbutamol nebulization (100-200 µgQ4h)/N-acetyl cysteine 20% nebulization (3cc Q4h) and if needed mechanical ventilation support. Study care treatment consist of: Standard care + Heparin nebulized administration(5000U every 4 hours for 7 days) and fresh frozen plasma intravenously administration (10 cc/Kg daily for 7 days) The patients' primary outcome will be assessed for Lung Injury Scale (LIS) every day by using fallowing parameters: (1) chest X-ray evaluated for alveolar consolidation (2) ratio of the partial pressure of oxygen in arterial blood to the inspiratory fraction of oxygen (3) PEEP level if ventilated (4) respiratory compliance if known Parameter Finding Value Rx.Torax no alveolar consolidation 0 alveolar consolidation de 1 quadrant 1 alveolar consolidation de 2 quadrant 2 alveolar consolidation de 3 quadrant 3 alveolar consolidation de 4 quadrant 4 Hypoxemia PaO2/FIO2 > 300 0 PaO2/FIO2 225 - 299 1 PaO2/FIO2 175 - 224 2 PaO2/FIO2 100 - 174 3 PaO2/FIO2 < 100 4 PEEP PEEP <= 5 cm H2O 0 PEEP 6 - 8 cm H2O 1 PEEP 9 - 11 cm H2O 2 PEEP 12 - 14 cm H2O 3 PEEP >= 15 cm H2O 4 Compliance >= 80 mL/cm H2O 0 compliance 60 - 79 mL/cm H2O 1 compliance 40 - 59 mL/cm H2O 2 compliance 20 - 39 mL/cm H2O 3 compliance <= 19 mL/cm H2O 4 2 The patients' secondary outcome will be assessed for mortality(for 28 days post injury), Coagulation tests(PT,PTT) (for 7 days post injury),ICU and hospital stay(for 7 days post injury) and duration of mechanical ventilation support(for 7 days post injury). In each group 85 Patients will be selected by simple randomization. Allocation ratio is1:1. Blinding of this study was not possible.