ECMO – the clinician’s view

Abstract

Background Extra corporeal membrane oxygenation (ECMO) is a complex rescue therapy used to provide cardiac and/or respiratory support for critically ill patients who have failed maximal conventional medical management. ECMO is based on a modified cardiopulmonary bypass (CPB) circuit, and can provide cardiopulmonary support for up‐to several months. It can be used in a veno venous configuration for isolated respiratory failure, (VV‐ECMO), or in a veno arterial configuration (VA‐ECMO) where support is necessary for cardiac +/‐ respiratory failure. The ECMO circuit consists of five main components: large bore cannulae (access cannulae) for drainage of the venous system, and return cannulae to either the venous ( in VV‐ECMO) or arterial (in VA ECMO) system. An oxygenator, with a vast surface area of hollow filaments, allows addition of oxygen and removal of carbon dioxide; a centrifugal blood pump allows propulsion of blood through the circuit at upto 10 L/minute; a control module and a thermoregulatory unit, which allows for exact temperature control of the extra corporeal blood. Methods The first successful use of ECMO for ARDS in adults occurred in 1972, and its use has become more commonplace over the last 30 years, supported by the improvement in design and biocompatibility of the equipment, which has reduced the morbidity associated with this modality. Whilst the use of ECMO in neonatal population has been supported by numerous studies, the evidence upon which ECMO was integrated into adult practice was substantially less robust. Results Recent data, including the CESAR study (Conventional Ventilatory Support versus Extra corporeal membrane oxygenation for Severe Respiratory failure)has added a degree of evidence to the role of ECMO in such a patient population. The CESAR study analysed 180 patients, and confirmed that ECMO was associated with an improved rate of survival. More recently, ECMO has been utilized in numerous situations within the critical care area, including support in high‐risk percutaneous interventions in cardiac catheter lab; the operating room, emergency department, as well in specialized inter‐hospital retrieval services. The increased understanding of the risk:benefit profile of ECMO, along with a reduction in morbidity associated with its use will doubtless lead to a substantial rise in the utilisation of this modality. As with all extra‐corporeal circuits, ECMO opposes the basic premises of the mammalian inflammation and coagulation cascade where blood comes into foreign circulation, both these cascades are activated. Anti‐coagulation is readily dealt with through use of agents such as heparin, but the inflammatory excess, whilst less macroscopically obvious, continues un‐abated. Platelet consumption and neutrophil activation occur rapidly, and the clinician is faced with balancing the need of anticoagulation for the circuit, against haemostasis in an acutely bleeding patient. Alterations in pharmacokinetics may result in inadequate levels of disease modifying therapeutics, such as an...

Extracorporeal Membrane Oxygenation System and Usage Areas: Review

“…dikkatli bir şekilde değerlendirilmeli ve buna göre destek tedavisine karar verilmelidir. 9,20 Kullanılacak kanülas-yonun tipine (VA ve VV) göre ECMO endikasyonları da değişebilmektedir (Tablo 2).…”

“…Ayrıca, kesin ve gö-receli kontrendikasyonlar ECMO tipine göre farklılık göstermektedir (Tablo 3). 9,20 ECMO KOMPLİKASYONLARI ECMO komplikasyonları hasta ve ECMO'dan kaynaklanan durumlarla yakından ilişkilidir. Buna ek olarak tüm ECMO uygulamalarında antikoagü-lasyon sağlanmalıdır, ancak kanama ve emboli riskinin önemli olduğu durumlarda ve tedavi baş-langıcında antikoagülasyonun azaltılması gerekmektedir (Tablo 4).…”

“…Buna ek olarak tüm ECMO uygulamalarında antikoagü-lasyon sağlanmalıdır, ancak kanama ve emboli riskinin önemli olduğu durumlarda ve tedavi baş-langıcında antikoagülasyonun azaltılması gerekmektedir (Tablo 4). 20 …”

“…Bununla TABLO 2: ECMO endikasyonları. 9,12,17,20,21 ECMO: Ekstrakorporeal membran oksijenatör; VA: Veno-arteriyel; VV: Veno-venöz, ARDS: Akut respiratuar distres sendromu. * Hastane içi kardiyak arrestlerde KPR yanıtı alınamıyorsa ECMO uygulanabilmektedir.…”

Selenium and oxidative stress modulation during extracorporeal circulation

“…30 There is still significant mortality associated with both veno-arterial (VA) and veno-venous (VV) ECMO, both during the course of ECMO itself and between successful weaning from ECMO and hospital discharge.…”