Perioperative Changes Of IL-6,IL-8 And IL-10 In Blood Serum During Mild Hypothermia Cardiopulmonary Bypass

Background and Objective:Cardiopulmonary bypass (CPB) is a very important auxiliary measure in open-heart surgery. But it could provoke systemic inflammatory response syndrome (SIRS) which related with many postoperative complications on account of its unphysiological mode of circulation. It even could raise the mortality of postoperative patients. So it is significant to the theory and practice of open-heart surgery that investigating the rules of perioperative systemic inflammatory response and researching the measures of palliating systemic inflammatory response and related complications.Recent years, a lot of documents indicating that many possible causes during CPB can activate the immune system, such as direct contact of the blood components with the artificial surface of the bypass circuit, unphysiological perfusion of CPB, operative trauma, ischemia reperfusion injury, bacterial translocation from intestine and temperature diversity, etc. During CPB, the delivery of inflammatory mediators and the interaction of various kind of inflammatory mediators can provoke water fall effect of inflammation, which can cause inflammatory reaction out of control and result in SIRS. The major functional mediators of inflammation during CPB are interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), which acting the center components on provoking SIRS. IL-6 is the excessive activator of acute phase proteins synthesized by hepatocyte. IL-6 can be regarded as one marker of acute phase reaction. IL-8 is one chemotaxin activator of neutrophilic leukocyte. It cause lung damage due to leukocytic infiltrate and participate in reperfusion injury of organism. Expression of IL-10 during CPB was regarded as an autoprotection mechanism which can inhibit the activity of histoleucocyte and macrophage and inhibit the composition of TNF-αand IL-6. The balance of anti-inflammatory and pro-inflammatory interleukins is consider significant to inflammation extent and clinical prognosis.Now about the technique of CPB has been consummated. The mode of mild hypothermia (rectal temperature, RT: 30℃-35℃) CPB has been given more and more attention. But the mode of hypothermia (rectal temperature, RT: <30℃) CPB has been challenged. In general, a lot of documents considered that, during hypothermia CPB, oxygen utilization and blood perfusion of organs, the releasing of anti-inflammatory factor IL-10, the effect to immunity, the change of temperature and the levels of pulmonary surfactants after operation are all inferior compared with mild hypothermia CPB.The data about dynamic diversify of systemic inflammation during mild hypothermia CPB have been reported scarcely. So, in order to provide a few beneficial evocations for choosing opportunity to prevent & cure SIRS by investigating the rules of systemic inflammation during mild hypothermia CPB with warm blood perfusion continuously, the following study aimed at surveying the changed tendency of inflammatory and anti-inflammatory response by examining the concentration's diversify of inflammatory factors (IL-6, IL-8) and anti-inflammatory factors (IL-10).Materials and Methods:1. Preference of case:24 cases of congenital heart disease undergoing mild hypothermia CPB with warm blood perfusion continuously were selected according to standards. They were all undergoing combined anesthesia.2. Sample collection:3. 5ml blood was sampled from radial artery individually before the operation (T₁), 30 minutes after CPB (T₂), and at 2 hours (T₃), 12 hours (T₄), 24 hours (T₅) after the end of CPB. 0.5ml blood was sent to be tested routinely and the rest of 3ml blood was centrifuged in 10 minutes at 3000r per minute, then was conserved at -80℃before being assayed.3. Assay method:Serum levels of IL-6,IL-8,IL-10 were measured by enzyme-linked immunosorbent assay technique (ELISA).4. Statistical analysis:The data were expressed in the form of ( x|-±s )and analysised by statistical treatment of multiple comparions (LSD-t or SNK analysis) or ANOVA of repeated measure. P <0.01 was regarded as significantly difference.Results:IL-6, IL-8, IL-10 serum concentrations of all cases increased significantly during CPB(P <0.01) and reached peak at about 2 hours after the end of CPB (T₃), then decreased gradually at about 12 hours after the end of CPB (T4). At about 24 hours after CPB(T₅), the serum levels of IL-6, IL-8, IL-10 were much higher compared with that at time point T₁(P <0.01), but had decreased significantly compared with that at time point T₃(P <0.01). No severe complication occurred after operation.Conclusions:Serum levels of IL-6, IL-8, IL-10 increase gradually after mild hypothermia CPB with warm blood perfusion continuously, and reach the peak at about 2 hours after the CPB and recover nearly to the normal level in 24 hours after CPB. No severe complication occur after operation and all patients recover successfully. Presentation of this result is that systemic inflammatory reaction takes place during mild hypothermia CPB and it is severe at 2 hours after operation , the best opportunity of adopting drastic measures to oppose systemic inflammatory reaction is since the beginning of CPB until 2 hours after operation.