Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• Extracorporeal support for severe ARDS in Australian practice

  Severe acute respiratory distress syndrome (ARDS) can progress despite lung-protective ventilation, prone positioning and correction of the precipitating illness. Extracorporeal membrane oxygenation (ECMO) can temporarily support gas exchange when respiratory failure is refractory, allowing the lungs to recover or bridging a complex treatment.

  At APSR 2022, the practical question is not whether ECMO is effective in every patient with ARDS. It is whether a particular patient is likely to benefit from days of extracorporeal support, and whether the treating team can deliver it safely.

  This review focuses on severe ARDS, patient selection, day-to-day management and the Australian environment in which ECMO is delivered. It does not replace local protocols or specialist consultation.

  Why ECMO is considered in severe ARDS

  ECMO oxygenates blood and removes carbon dioxide through a membrane circuit. In isolated lung failure, venovenous ECMO supports pulmonary function without directly assisting the heart; venoarterial or hybrid configurations may be needed when myocardial function is also compromised.

  Evidence is strongest for selected patients with refractory hypoxaemia or severe respiratory acidosis. The EOLIA trial raised concerns about bleeding and other complications, while subsequent observational studies have reported survival benefit in the sickest subgroup. This supports a rescue strategy, not routine placement.

  Before ECMO, teams should optimise PEEP, recruitment strategies where safe, prone positioning, sedation and treatment of infection, pulmonary embolism or aspiration. ECMO is considered when these measures cannot maintain acceptable oxygenation or ventilation.

  Selecting patients and choosing the configuration

  Severe ARDS generally means a very low oxygenation ratio despite meaningful PEEP, but referral thresholds are centre-specific and depend on trajectory rather than a single measurement. Common triggers include persistent hypoxaemia, worsening hypercapnia despite lung-protective ventilation, or shock with respiratory failure.

  Potential candidates must have a reversible cause and a plausible period of recovery. Irreversible brain injury, uncontrolled bleeding, profound immunosuppression and some advanced conditions may argue against ECMO, although age and comorbidity are not absolute exclusions. A multidisciplinary discussion should address baseline function, reversibility and the patient’s goals.

  The configuration follows physiology. Venovenous ECMO suits severe respiratory failure with preserved cardiac function. Venoarterial support may be required for cardiogenic shock, and central cannulation or additional return cannulas may be used in selected cases. Transport and the urgency of stabilising the patient also influence the plan.

  Delivering ECMO safely

  Cannulation, circuit choice, anticoagulation and ventilation must be coordinated by a trained team. Oxygenation, carbon dioxide removal, blood flow, pre- and post-oxygenator pressure, haemodynamics, temperature and circuit integrity require continuous monitoring. Alarm limits and emergency protocols matter as much as the pump settings.

  Lung-protective ventilation continues during ECMO, with low tidal volumes and cautious PEEP. Sweeping the circuit can help reduce recirculation, while proning and recruitment remain individualised. Sedation, analgesia, nutrition, mobilisation and delirium prevention should proceed alongside mechanical support.

  Anticoagulation balances clot prevention against bleeding. Circuit thrombosis, oxygenator failure, cannula malposition, infection and access complications need clear escalation plans. Major haemorrhage, neurological injury, vessel injury and equipment failure are uncommon but consequential, so simulation and regular competency review are central to a safe service.

  Embedding ECMO in Australian critical care

  ECMO is concentrated in specialist public hospitals in Melbourne, Sydney, Brisbane, Perth and Adelaide. In New South Wales, the Interstate and Intrastate Critical Care Adult Retrieval Network coordinates critical-care transfers, while interstate teams and aeromedical services handle long-distance retrieval. Rural and remote hospitals therefore need an early pathway to a capable centre.

  The local market is hospital based. Public-hospital tenders, local distributors and imported disposable sets shape availability, while oxygenators, tubing and pumps are regulated by the Therapeutic Goods Administration. Australian Border Force requirements also affect customs clearance and landed cost, making buffer stock and backup consumables important.

  For an admitted public patient, ECMO is generally provided within state-funded tertiary services and is not usually a separately itemised Medicare service. Cost and governance should therefore be considered across the referring and receiving hospitals. Australian practice also requires careful next-of-kin communication, culturally appropriate interpreter use and early clarification of goals when recovery is uncertain.

  Limits, complications and alternative paths

  ECMO buys physiological time; it does not reverse the cause of ARDS or guarantee neurological recovery. Delays in treating pneumonia, sepsis, aspiration or another driver can negate the benefit. If there is no realistic bridge to recovery, a difficult decision to withdraw support should be anticipated rather than deferred.

  Some patients are too unstable for ECMO, while others may recover with less invasive treatment. High-frequency ventilation, prone positioning, inhaled pulmonary vasodilators and selective inhaled anaesthesia remain specialist options with their own evidence and limitations. These approaches may be more appropriate when bleeding risk, futility or patient preference argues against extracorporeal support.

  When critical illness accompanies malignancy, intensive care and oncology must define whether definitive treatment remains feasible. For early esophageal cancer, a review of laser therapy evidence can inform that separate oncological discussion, but it cannot justify ECMO without independent evidence of reversibility and recovery potential.

  Recommendations for safe ECMO delivery in Australia

  A referral and delivery protocol should connect regional intensive care units with ECMO centres before a crisis. The recommendations below focus on actions that can be standardised while preserving patient-specific decisions.

  • Establish one regional referral number and a 24-hour response standard for suspected severe ARDS.
  • Review candidacy with critical care, respiratory medicine, nursing, perfusion or extracorporeal support staff, and the patient’s family when feasible.
  • Document baseline severity, trajectory, reversibility, contraindications and goals of care before cannulation.
  • Continue lung-protective ventilation and prone positioning while preparing for transfer or circuit change.
  • Match cannula configuration and circuit complexity to physiology, transport needs and the expertise available.
  • Audit indications, mortality, bleeding, thrombosis, infection, equipment failures and decisions to withdraw support.

  Success depends on early recognition, disciplined selection and reliable transfer, rather than speed alone. Governance should compare outcomes with international benchmarks while also reviewing equity, rural access and communication with families.

  Turning evidence into a referral decision

  A useful conference discussion should leave the clinical team with a reproducible decision process. Local thresholds, transfer arrangements and after-hours contacts should be visible, and uncertainty should trigger consultation rather than an improvised decision at the bedside.

  For the next candidate, the concrete next step is a documented multidisciplinary ECMO review before the next major ventilation escalation, with the referral outcome and reasons recorded in the patient’s electronic health record.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)