Adult venovenous extracorporeal membrane oxygenation for severe respiratory failure: Current status and future perspectives

Abstract

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure was proposed more than 40 years ago. Despite the publication of the ARDSNet study and adoption of lung protective ventilation, the mortality for acute respiratory failure due to acute respiratory distress syndrome has continued to remain high. This technology has evolved over the past couple of decades and has been noted to be safe and successful, especially during the worldwide H1N1 influenza pandemic with good survival rates. The primary indications for ECMO in acute respiratory failure include severe refractory hypoxemic and hypercarbic respiratory failure in spite of maximum lung protective ventilatory support. Various triage criteria have been described and published. Contraindications exist when application of ECMO may be futile or technically impossible. Knowledge and appreciation of the circuit, cannulae, and the physiology of gas exchange with ECMO are necessary to ensure lung rest, efficiency of oxygenation, and ventilation as well as troubleshooting problems. Anticoagulation is a major concern with ECMO, and the evidence is evolving with respect to diagnostic testing and use of anticoagulants. Clinical management of the patient includes comprehensive critical care addressing sedation and neurologic issues, ensuring lung recruitment, diuresis, early enteral nutrition, treatment and surveillance of infections, and multisystem organ support. Newer technology that delinks oxygenation and ventilation by extracorporeal carbon dioxide removal may lead to ultra-lung protective ventilation, avoidance of endotracheal intubation in some situations, and ambulatory therapies as a bridge to lung transplantation. Risks, complications, and long-term outcomes and resources need to be considered and weighed in before widespread application. Ethical challenges are a reality and a multidisciplinary approach that should be adopted for every case in consideration.

Limiting sedation for patients with acute respiratory distress syndrome – time to wake up

“…Minimizing sedation in these patients should remain an important goal to minimize delirium, increase patient mobilization, and optimize patient recovery. 40 …”

Veno-Venous Extracorporeal Membrane Oxygenation for Acute Lung Injury after Surgery for Aortic Dissection: A Case Report

“…The fraction of recirculation is influenced by cannula configuration and positioning [23]. When clinically significant, recirculation may be improved by adjusting cannula position, manipulating other factors to allow for decreased flow, adding a second drainage cannula, or using a well-placed dual-lumen cannula.…”

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure

“…The venous blood with low oxygen saturation (SvO 2 ) is typically drained from superior vena cava, inferior vena cava, and/or large vein such as femoral or subclavian vein. It passes through the oxygenator [15] and then returns to the patient in or near the right atrium [16]. The returned blood with high oxygen content is mixed with systemic venous blood and enters into right heart.…”

“…However, due to low mechanical ventilation setting, such oxygenation is always negligible. Mechanical ventilation in this regard is more to keep the lung open than to provide oxygen [16]. However, native lung function is not always negligible; this may be the case for native lung CO 2 removal.…”