Study exclusion criteria
| Exclusion criteria | Justification |
|---|---|
| Antiplatelet therapy on admission or within 7 days prior to admission | Inability to ethically randomise |
| Presented to outside hospital emergency department >12 h before arrival at site's facility | Inability to enrol within time frame for possible benefit |
| Inability to obtain consent and randomise within 12 h of hospital presentation | Inability to enrol within time frame for possible benefit |
| Admitted for elective or emergency surgery | Aspirin not found to benefit this group in preliminary studies |
| ALI on hospital presentation or prior to randomisation | Inability to adequately assess outcome |
| Presentation believed to be due to pure heart failure and no other known risk factors for ALI | Inability to adequately assess outcome |
| Receiving mechanical ventilation through a tracheostomy tube prior to current hospital admission (patient who is ventilator dependent) | Inability to adequately assess outcome |
| Bilateral pulmonary infiltrates present on admission only if the patient has a history of interstitial lung disease that can reasonably explain the current degree of pulmonary infiltrates present | Inability to adequately assess outcome |
| Allergy to aspirin or NSAIDs | Intervention contraindicated |
| Bleeding disorder* | Intervention contraindicated |
| Suspected active bleeding or judged to be at high risk for bleeding complications | Intervention contraindicated |
| Presence of acute kidney injury† | Intervention contraindicated |
| Severe chronic liver disease (Child-Pugh class C) | Intervention contraindicated |
| Active peptic ulcer disease (within past 6 months) | Intervention contraindicated |
| Pregnancy or breast feeding | Intervention contraindicated |
| Inability to administer study drug | Unable to administer study drug |
| Expected hospital stay <48 h | Incomplete study procedures and outcome data |
| Admitted for comfort or hospice care | Incomplete study procedures and outcome data |
| Patient, surrogate or physician not committed to full support (exception: a patient will not be excluded if he/she would receive all supportive care except for attempts at resuscitation from cardiac arrest) | Unable to assess primary outcome |
| Not anticipated to survive >48 h | Incomplete study procedures and outcome data |
| Previously enrolled in this trial | Violates the statistical assumption of sample independence |
| Enrolment in concomitant intervention study | Potential confounding and co-enrolment interactions |
*Any disorder with known associated with increased risk of bleeding. Common disorders may include thrombocytopaenia, disseminated intravascular coagulation, haemophilia, von Willebrand disease, oral anticoagulant therapy or advanced liver disease with associated coagulation disorders. Platelet count <50000 or absence of platelet count in the previous 24 h to allow for assessment of platelet status.
†Acute kidney injury defined as ‘R’ or greater according to RIFLE criteria.
ALI, acute lung injury; NSAIDs, non-steroidal anti-inflammatory medications.