Abstract 3122: High Dose Insulin Therapy Attenuates Systemic Inflammatory Response in Patients Undergoing Elective Coronary Artery Bypass Grafting
Background: Cardiac surgery with cardiopulmonary bypass (CPB) induces an acute phase reaction that has been implicated in the pathogenesis of several postoperative complications. Some studies showed that pro-inflammatory cytokines are increased by acute hyperglycemia-.Recent evidence suggested that insulin has anti-inflammatory properties. Therefore our hypothesis is that high dose insulin therapy while maintaining normoglycemia attenuates the systemic inflammatory response to CPB in coronary artery bypass grafting (CABG) patients.
Methods: After approval by the research ethics committee and obtaining a written informed consent, 50 patients who presented for elective CABG were randomized to either the standard of care group (n=25) who received insulin sliding scale starting at blood glucose concentrations >10mmol/L or the high dose insulin therapy group (n=25) who received insulin infusion at 5mU/kg/min starting from arrival at the operating room until the end of the surgical procedure. Dextrose 20% was infused at a rate adjusted to maintain a BG of 4 – 6mmol/L. Blood samples were collected preoperatively, on arrival to the intensive care unit (ICU), 6, 24 and 48 hours postoperatively to determine white blood cells count (WBC), high sensitivity C reactive protein (hsCRP), Tumor necrosis factor α (TNFα), interlukin 6 and 8 (IL6, IL8), C1 esterase inhibitor (C1EI) and complement factor 3 and 4 (C3, C4).
Results: Biometric, demographic and operative characteristics particularly CPB and cross clamp time were similar between the two groups. There were lower levels of IL6, IL8 and TNFα in the early post operative period as shown in the table⇓ below: Levels of IL6, IL8 and TNFα were comparable 24 and 48 hours post operatively. There was no difference in the levels of WBC, C3, C4, hsCRP nor C1EI between the two groups.
Conclusion: High dose insulin therapy blunts the early postoperative surge in inflammatory response to CPB as reflected by decreased levels of IL6, IL8 and TNFα.