Venovenous ECMO for Severe Breathing Problems

Inclusion Criteria: 1. Patients ≥18 to 65 years old 2. Acute hypoxemic respiratory failure characterised by new or worsening respiratory symptoms developing within 2 weeks prior to the onset of need for oxygen or respiratory support 3. Mechanical ventilation of \<7 days 4. Moderate to severe respiratory failure, as demonstrated by two P:F ratios \<150mmHg at least 6 hours apart. Arterial Blood Gases (ABG) with P:F ratio \> 150mmHg are permitted between the two trial inclusion ABGs. 5. Trial of proning (unless contraindicated) Exclusion Criteria: 1. The patient will be extubated today or tomorrow (i.e. will not remain intubated and ventilated the day after tomorrow) 2. Cardiogenic cause of respiratory failure 3. Chronic hypercapnic respiratory failure defined as PaCO2 \> 60 mmHg in the outpatient setting 4. Home mechanical ventilation (non-invasive ventilation or via tracheotomy) except for CPAP/BIPAP used solely for sleep disordered breathing 5. Confirmed diffuse alveolar haemorrhage from vasculitis 6. Neurologic conditions, i.e. undergoing treatment for intracranial hypertension 7. Currently receiving any form of ECMO (e.g., venovenous, venoarterial, or hybrid configuration) 8. Patient needing immediate VV ECMO (as per EOLIA criteria) 9. The patient is moribund and deemed unlikely to survive past 24 hours (as determined by the clinical team) 10. The patient is being transitioned to palliative care 11. Contraindications to anticoagulation (e.g., active GI bleeding, bleeding predisposition, severe trauma) 12. Previous hypersensitivity/anaphylactic reaction to heparin or heparin-induced thrombocytopenia 13. Participation or Consent is declined, OR 14. Unable to identify or Contact surrogate decision maker.