Inflammation and Oxidative Stress in the Context of Extracorporeal Cardiac and Pulmonary Support

Abstract

Extracorporeal circulation (ECC) systems, including cardiopulmonary bypass, and extracorporeal membrane oxygenation have been an irreplaceable part of the cardiothoracic surgeries, and treatment of critically ill patients with respiratory and/or cardiac failure for more than half a century. During the recent decades, the concept of extracorporeal circulation has been extended to isolated machine perfusion of the donor organ including thoracic organs (ex-situ organ perfusion, ESOP) as a method for dynamic, semi-physiologic preservation, and potential improvement of the donor organs. The extracorporeal life support systems (ECLS) have been lifesaving and facilitating complex cardiothoracic surgeries, and the ESOP technology has the potential to increase the number of the transplantable donor organs, and to improve the outcomes of transplantation. However, these artificial circulation systems in general have been associated with activation of the inflammatory and oxidative stress responses in patients and/or in the exposed tissues and organs. The activation of these responses can negatively affect patient outcomes in ECLS, and may as well jeopardize the reliability of the organ viability assessment, and the outcomes of thoracic organ preservation and transplantation in ESOP. Both ECLS and ESOP consist of artificial circuit materials and components, which play a key role in the induction of these responses. However, while ECLS can lead to systemic inflammatory and oxidative stress responses negatively affecting various organs/systems of the body, in ESOP, the absence of the organs that play an important role in oxidant scavenging/antioxidative replenishment of the body, such as liver, may make the perfused organ more susceptible to inflammation and oxidative stress during extracorporeal circulation. In the present manuscript, we will review the activation of the inflammatory and oxidative stress responses during ECLP and ESOP, mechanisms involved, clinical implications, and the interventions for attenuating these responses in ECC.

Diagnosis, pathophysiology and preventive strategies for cardiac surgery-associated acute kidney injury: a narrative review

“…IRI may also exacerbate oxidative inflammatory stress during CPB, leading to an increase in circulating free labile iron [ 76 ]. Labile catalytic iron can damage renal epithelial cells, impair cell proliferation, and induce lipid peroxidation and protein oxidation [ 77 ].…”

Overview of oxidative stress and the role of micronutrients in critical illness

“…73,74 Antioxidant supplementation has been proposed to ameliorate this proinflammatory state. 21,73 Among the antioxidants studied the evidence supporting vitamin C supplementation, especially in cardiac surgery patients, is the strongest, revealing shorter ICU and hospital LOS, a decrease in mechanical ventilation requirement, and lower incidence of atrial fibrillation. 75…”

“…Regarding zinc, a meta‐analysis ( n = 4 studies) including 761 patients receiving zinc supplementation compared with 712 receiving standard care showed a slight increase in the length of ICU stay and no improvement in the overall survival for the study group, suggesting that there is no evidence to support zinc supplementation in hospitalized patients with COVID‐19 71 . Generally, the use of natural bioactive compounds (eg, zinc + polyphenols) is subject of current research and might be a promising approach to affect the immune system's response to illness 72,73 …”

Fluid overload and mortality in critically ill patients with severe heart failure and cardiogenic shock–An observational cohort study

“…Organ congestion is a classical feature of HF ( 4 – 7 ) that is caused by excess fluid or fluid redistribution into the extravascular space ( 7 ). In addition, during and after cardiac surgery (CS) or cardiac interventions, the infusion of considerable amounts of IV fluids may be necessary ( 7 , 8 ) due to cardiopulmonary bypass (CPB) induced inflammation ( 8 ), blood loss, myocardial depression, rhythm disturbances, and impaired vascular tone ( 9 ). Therefore, additional iatrogenic FO is common at ICU admission in patients with HF and may affect critical care outcomes ( 10 , 11 ).…”