Volatile Anesthetic Preconditioning Attenuates Ischemic-reperfusion Injury In Type â…¡ Diabetic Patients Undergoing On-pump Heart Surgery

Background:Conflicting evidence is existing that whether diabetic myocardium is afforded by ischemic preconditioning (IP) or not. In experimental studies, volatile anesthetic drugs are proven to mimic the IP. However, clinical data is still lacking with a strong evidence.Purpose:The study was conducted to evaluate the cardioprotective effect of volatile anesthetic preconditioning (AP) in the diabetic and non-diabetics patients undergoing heart surgery. We applied sevoflurane as AP agent and studied its cardioprotective effect and postoperative outcome.Methods:Total40patients were recruited.20Diabetic Mellitus (DM) patients were randomly selected into two groups (10patients per each group):DM patients with no AP and DM patients with AP. Another20non-DM patients were randomly grouped into non-DM with AP and non-DM with AP. Patients of the AP group received1%MAC sevoflurane for5min, interspersed by5min washout for three times prior to establishing the CPB. TnI and CK-MB were measured as marker of myocardial injury. Tissue sample from atrial trabeculae harvested for Western Blot analysis of total and phosphorylation of PKC, PTEN, STAT3, eNOS, Akt activation.Results:There w ere no significant differences regarding preoperative demographic data. Peak of Tn1defined at5hour postoperatively in the DM group without preconditioning;2.1±1.03ng/ml vs.1.65±0.65ng/ml in the DM+Sevo group (p<0.05). In the non-DM group, the group without AP were also observed higher TnI level as1.6±0.62ng/ml vs.1.2±2.45ng/ml. Total amount of CK-MB released was higher in the group without AP than groups with AP (39.2±3vs36.3±4in DM groups and28.5±3.4vs21.4±5.6in non-DM groups respectively, p<0.02). In the Western Blot, only phosphorylation of PKC and total-STAT3showed some difference. Lengths of postoperative intubation, postoperative stay in the ICU were significantly longer in non-AP groups, as well as length of hospital stay.Conclusion:This study showed that sevoflurane-induced preconditioning is provides better cardioprotection and cardiac function postoperatively. The diabetic patients still benefit from preconditioning of volatile anesthetics. However, larger randomized trials are needed to carry out to clarify the protocol used for AP and follow-up checkups for long-term outcome.for long-term outcome.