Causes of Multiple Organ Dysfunction During Cardiosurgical Operations under Extracorporeal Circulation

Abstract

Objective: to reveal possible causes of postoperative multiple organ dysfunction syndrome (MODS) in patients after surgery under extracorporeal circulation (EC), by measuring the level and balance of pro- and anti-inflammatory cytokines. Subjects and methods. The investigation enrolled 162 patients who had undergone operations on the heart and thoracic aorta. The levels of interleukins (IL)-6, IL-8, and IL-10 were determined by ELISA. Results. At surgery under EC, MODS was encountered in 5.7%, mortality was 55.6%. The principal causes of MODS were prolonged EC concurrent with bleeding (23%), massive hemorrhage (16%), perioperative myocardial infarction and cardiogenic shock (15%), prolonged EC (12%), acute lung injury (12%), disseminated intravascular coagulation (10%), allergic and anaphylactic reactions (9%), and intravascular hemolysis (6%). The levels of pro- and anti-inflammatory cytokines were substantially increased in all the patients after surgery under EC irrespective of the presence of MODS in the postoperative period. The patients with MODS displayed pro- and anti-inflammatory cytokine imbalance due to a preponderance of the proinflammatory activity of a systemic response. During massive hemorrhage (more than 20 ml/kg), the patients with MODS exhibited a reduction in the two pools of cytokines. In the absence of MODS, there was a parallel increase in both pro- and anti-inflammatory cytokines. The magnitude of a change in the level of cytokines is related to the volume of blood loss. During prolonged EC (more than 170 min), the patients with MODS had a higher pro- and anti-inflammatory cytokine ratio due to the elevated levels of both pools, but the elevation of anti-inflammatory cytokines was more pronounced. In the patients without MODS, the values of both groups of interleukins were sigmficantly unchanged with longer duration of EC. Key words: multiple organ dysfunction syndrome, systemic inflammatory reaction, interleukins 6, 8, 10, extracorporeal circulation, operations on the heart and thoracic aorta.