In this prospective study of 60patients, we tested the hypothesis That markedly elevated levels of plasma von Willebrand factor (VWF) a marker of endothelial cell injury might predict the development of acute respiratory distress syndrome (A.R.D.S) in risky patients. We compared our result to IL.6 as control biomarker for A.R.D.S development.

Acute lung injury was quantified on two -point scoring system (Berlin definition of ARDS and Murray score of acute lung injury).

Plasma levels of both vWF and IL.6 were be measured on T=0 i.e. (at start of the study once the patient considered to be risky for A.R.D.S development to obtain their baseline levels), T=48 (after 48 hours), and T=72 (after 72 hours).

Inclusion Criteria:

• Patients between 18 and 80 years old of both sexes.
• risk factor for development of acute respiratory distress syndrome or acute lung injury either by:
• Direct lung injury includes: Severe pneumonia (infection), Breathing a vomited stomach contents (aspiration), Breathing harmful fumes or smoke, severe trauma to the chest or other accident that bruises the lungs.
• Indirect lung injury includes: sepsis, Severe injury or trauma with shock, blood transfusions , drug overdose acute pancreatitis, fracture of the long bones, near drowning ,anaphylaxis, uremia, fat embolus , and intracranial insult.

Exclusion Criteria:

• (1) pregnancy;
• (2) a preexisting medical condition with a life expectancy less than 3 months
• (3) evidence of cardiogenic pulmonary edema
• (4) age under 18 years old or above 80 years old
• (5) late stages of liver cell failure, renal failure
• (6) severe myocardial infarction
• (7) deep coma.

60 patients, admitted to the ICUs, staying >24 hrs will be randomly assigned to enter this study.