Enrolled in another clinical trial that is unapproved for co-enrolment Heparin allergy or heparin-induced thrombocytopaenia APTT > 120 seconds and this is not due to anticoagulant therapy Platelet count < 20 x 10^9 per L Pulmonary bleeding Uncontrolled bleeding Pregnant or might be pregnant Receiving or about to commence ECMO or HFOV Myopathy, spinal cord injury, or nerve injury or disease with a likely prolonged incapacity to breathe independently e.g. Guillain-Barre syndrome Acute brain injury that may result in long-term disability Usually receives home oxygen Dependent on others for personal care due to physical or cognitive decline Death is imminent or inevitable within 24 hours The clinical team would not be able to set up the study nebuliser and ventilator circuit as required including with active humidification Clinician objection

Enrolled in another clinical trial that is unapproved for co-enrolment Heparin allergy or heparin-induced thrombocytopaenia APTT > 120 seconds and this is not due to anticoagulant therapy Platelet count < 20 x 10^9 per L Pulmonary bleeding Uncontrolled bleeding Pregnant or might be pregnant Receiving or about to commence ECMO or HFOV Myopathy, spinal cord injury, or nerve injury or disease with a likely prolonged incapacity to breathe independently e.g. Guillain-Barre syndrome Acute brain injury that may result in long-term disability Usually receives home oxygen Dependent on others for personal care due to physical or cognitive decline Death is imminent or inevitable within 24 hours The clinical team would not be able to set up the study nebuliser and ventilator circuit as required including with active humidification Clinician objection