Intubated and on mechanical ventilation, or requiring immediate intubation as per the treating clinicianâ??s assessment <br/ >Heparin allergy or heparin-induced thrombocytopaenia <br/ >APTT > 120 seconds, not due to anticoagulant therapy and does not correct with administration of fresh frozen plasma <br/ >Platelet count < 20 x 109 per L <br/ >Pulmonary bleeding or uncontrolled bleeding <br/ >Pregnant or might be pregnant <br/ >Acute brain injury that may result in long-term disability <br/ >Myopathy, spinal cord injury, or nerve injury or disease with a likely prolonged incapacity to breathe independently e.g. Guillain-Barre syndrome <br/ >Treatment limitations in place, i.e. not for intubation, not for ICU admission <br/ >Death is imminent or inevitable within 24 hours <br/ >Clinician objection <br/ >Refusal of participant consent <br/ >

Intubated and on mechanical ventilation, or requiring immediate intubation as per the treating clinicianâ??s assessment <br/ >Heparin allergy or heparin-induced thrombocytopaenia <br/ >APTT > 120 seconds, not due to anticoagulant therapy and does not correct with administration of fresh frozen plasma <br/ >Platelet count < 20 x 109 per L <br/ >Pulmonary bleeding or uncontrolled bleeding <br/ >Pregnant or might be pregnant <br/ >Acute brain injury that may result in long-term disability <br/ >Myopathy, spinal cord injury, or nerve injury or disease with a likely prolonged incapacity to breathe independently e.g. Guillain-Barre syndrome <br/ >Treatment limitations in place, i.e. not for intubation, not for ICU admission <br/ >Death is imminent or inevitable within 24 hours <br/ >Clinician objection <br/ >Refusal of participant consent <br/ >