J Extra Corpor Technol 2025 , 57 , 56 – 57 Ó The Author ( s ), published by EDP Sciences , 2025 https :// doi . org / 10.1051 / ject / 2024034
Available online at : ject . edpsciences . org
LETTER TO THE EDITOR
Infection as an indicator and additional factor for consideration of ECMO circuit change-out : A call for further research
Salman Pervaiz Butt ( MBA , M . Sc ) 1 ,* , Stephanie Thomas ( MBChB , FRCPath ) 2 , and Salman Abdulaziz ( MBBS , FRCP ) 3
1 Interim Manager Perfusion Services , Heart Vascular and Thoracic Institute , Cleveland Clinic Abu Dhabi , PO BOX 112412 , United Arab Emirates 2 Consultant Medical Microbiologist , Manchester University Foundation Trust , Manchester M13 9WL , UK 3 Consultant of Cardiovascular Critical Care , Co-Chair of ECMO Task Force , Department of Health , PO Box 5674 , 20224 ,
United Arab Emirates Received 13 May 2024 , Accepted 9 September 2024
Dear Editor
We write in response to our recently published article , entitled “ Improving ECMO therapy : Monitoring oxygenator functionality and identifying key indicators , factors , and considerations for changeout ” [ 1 ]. While we continue to support our conclusion , that thrombosis within the membrane oxygenator is a significant contributor to dysfunction , and that the decision for circuit change-out requires considering factors such as fibrinogen levels , blood gases , plasma-free haemoglobin , D-dimers , platelet function , flows , pressures , and anticoagulation strategy , we feel that we overlooked the influence of infection on coagulation and its role as a possible additional factor that might also determine changeout of the system .
We now also propose , that there may be a significant relationship between infection and circuit dysfunction which has not previously been explored or fully described [ 2 ]. It is widely reported in the literature that the inflammatory state associated with COVID-19 infection may amplify the proinflammatory effect of ECMO [ 3 ]. The clinical consequences of this are bleeding and thrombosis , which may negatively impact circuit function necessitating changeout .
However , we suggest that in addition to viral infection , bacterial and fungal infection , particularly in those patients with positive blood cultures where pathogenic organisms are circulating in the bloodstream , around the circuit , and through the oxygenator , may provoke inflammatory responses and contribute to clot formation and build up within the oxygenator , potentially compromising oxygenator functionality .
The mechanisms by which infection-associated thrombosis is induced , maintained , and resolved are poorly understood , as is the contribution thrombosis makes to host control of infection and pathogen spread . The key difference between infectionassociated thrombosis and thrombosis in other circumstances is a stronger inflammation-mediated component caused by the
* Corresponding author : buttsab9 @ hotmail . com presence of the pathogen and its products . This inflammation triggers the activation of platelets , which may accompany damage to the endothelium , resulting in fibrin deposition and thrombus formation . This process is often referred to as thrombo-inflammation [ 4 ]. Therefore , we hypothesis that bacterial and fungal bloodstream infection may also be a factor to consider when contemplating oxygenator changeout .
In addition and conversely , we also suggest that clots residing within the oxygenator due to other thrombotic mechanisms as described in the author ’ s paper [ 1 ], may offer favourable conditions for microbial adherence and biofilm formation , increasing the risk of microbial persistence in the circuit [ 5 ]. This would be of particular significance for those pathogens commonly associated with infection in the Intensive Care patient , such as coagulase-negative staphylococcus , Pseudomonas aeruginosa and Candida species . These pathogens form biofilm readily on biotic or abiotic surfaces , which allows evasion from the host immune system and promotes antibiotic resistance .
We suggest a two-way relationship between infection and clot formation in the ECMO circuit , highlighting the interconnected nature of mechanical and infectious complications in critically ill patients requiring extracorporeal support . We suggest that further research is warranted to understand the complex relationship between bacterial and fungal bloodstream infection , time to clot formation and circuit dysfunction . This should be preceded by an extensive literature review on the subject , followed by recommendations for further , targeted research . Studying such a complex multifactorial system is all the more challenging in the ECMO population which typically consists of patients with profound heterogeneity of characteristics . A better understanding may allow the instigation of early pre-emptive measures , including bloodstream surveillance , adjustment of blood thinners , targeted antibiotics with antibiofilm activity and untimely guidance on the optimisation of oxygenator changeout , thereby optimizing ECMO therapy .
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( https :// creativecommons . org / licenses / by / 4.0 ), which permits unrestricted use , distribution , and reproduction in any medium , provided the original work is properly cited .