Nebulised heparin for lung injury

INTERVENTION: Randomised to nebulised liquid heparin (25,000 IU in 5 ml) versus placebo (5 ml of nebulised liquid 0.9% sodium chloride). The study medication is given every six hours for up to 10 days while the patient requires ventilation. CONDITION: Patients with or at risk of developing Acute Respiratory Distress Syndrome. PRIMARY OUTCOME: Physical function assessed using the physical function component of the SF‐36 health survey. SECONDARY OUTCOME: Change in Murray Lung Injury Score assessed by review of medical records Change in plasma thrombin time, D‐Dimer, antithrombin thrombin levels and serum cytokines assessed by blood analysis Development of ALI or ARDS assessed by review of medical records Healthcare utilisation assessed by review of medical records Hospital stay duration assessed by review of medical records ICU stay duration assessed by review of medical records Lung rescue therapies assessed by review of medical records Major bleeding or other complications assessed by review of medical records Mechanical ventilation‐free days assessed by review of medical records mortality assessed by review of medical records and contact with patient or next of kin Quality of life assessed by contact with patient or next of kin and undertaking EQ5D survey INCLUSION CRITERIA: Receiving ventilation via an endotracheal tube Started ventilation via an endotracheal tube yesterday or today Expected to require invasive ventilation for at least all of today and all of tomorrow PaO2 to FiO2 ratio less than 300 Active ventilator circuit humidification