The effects of thoracic epidural anesthesia with general anesthesia on reperfusion injury in open heart surgery

In open-heart surgery, almost all patients suffer a little of myocardial damage. Onereason for this damage is ischemia-reperfusion injury. In our study, it has been aimed tosearch the effects of thoracic epidural analgesia, added to general anesthesia, of whichanalgesic properties are well-known and therefore often used in surgeries involving theupper abdomen and chest area on myocardial tissue reperfusion damage during open heartsurgery.Our study has been performed at Farabi Hospital Operating Room andCardiovascular Surgery Operating Room, Faculty of Medicine, KTU, and postoperativefollow-up has been performed in the Cardiovascular Surgical Intensive Care Unit. AfterEthics Committee?s approval, the study has been performed on a total of 40 patients, whowould have cardiac surgery and were in ASA 2-3 index, between 18-80 years of age. Allpatients have been evaluated as standard before anesthesia and consent form has beenobtained.Invasive and noninvasive monitoring (ECG, peripheral O2 saturation, invasivearterial monitoring, heat, bispectral index, and urine monitoring, central venouscatheterization) has been performed to all patients to have surgery. In addition, thoracicepidural catheter has been placed to all patients without contraindications for intraoperativeand postoperative analgesia in addition to general anesthesia. Electrolyte,hemoglobin, blood glucose and blood gas values of the patients have been recorded.The first 20 patients without contraindications for epidural catheterization formed theepidural + general anesthesia group (Group E). The first 20 patients who haven?t beenplaced epidural catheter formed the general anesthesia group (Group G).In the operating room, after monitoring the heart rate, non-invasive blood pressureand peripheral oxygen saturation, arterial cannulation has been performed for bloodsampling. Epidural catheter has been placed to Group E in T5-T6 intervertebral area andstandard epidural analgesia was performed with 10 mg levobupivakain. 10 mg/hlevobupivakain infusion has been started from epidural catheter and this infusion has beencontinued for up to 48 hours postoperatively. Intra-operative and postoperative analgesia ofthe patients, who weren?t placed the epidural catheter, has been provided with fentanylinfusion.Before the surgery, first blood sample has been taken at this stage from the artery ofcannulation for IMA, MDA, TAS, TOS, and blood gas values. Meanwhile, heart rate,blood pressure and peripheral oxygen saturation have been recorded. Then, performing theinduction of standard general anesthesia to all patients with fentanyl, rocuronium andthiopental, patients vere intubated. Anesthesia has been maintained with 1-2 % sevofluranein the 50-50% O2-air mixture. Other blood sampling and vital parameters records has beenrecorded totally 11 times; 5 min before the aortic cross clamp (ACC) being placed, 5minutes before removing the ACC, 10, 30, 60 minutes and 2, 3, 6, 12, 24 hours laterremoving the ACC.After the surgery, the patients have been transferred to Cardiac Surgery IntensiveCare Unit. In postoperative intensive care unit, heart rate, blood pressure and peripheraloxygen saturation have been recorded in the hours of scheduled. In the same way, bloodhas been taken for the values of IMA, MDA, TAS, TOS and blood gas, and it has beenstudied at Biochemistry Research Lab of our hospital.In our study, it has been noticed that IMA values, which have been measured 10, 60minutes and 12, 24 hours later the ACC removes, are lower in Group E than Group G aftercomparison of IMA values of two groups, that TOS values, which have been measured 30and 60 minutes and 2 and 3 hours later the ACC removes, are lower in Group E thanGroup G after comparison of TOS values, that TAS values, which have been measured 3,6and 12 hours later the clamp, are higher in Group E than Group G after comparison of TASvalues, but that MDA values haven?t differed in two groups after the comparison of MDAvalues. In the same way, when heart rate values, which is one of the hemodynamicparameters of two groups, are compared, it has been noticed that values, before the surgeryand the values of heart rate 5 minutes before the ACC being placed, are lower in Group Ethan Group G, and that the mean arterial pressure, which have been measured 5 minutesbefore the AKK being placed, are lower in group E than Group G when we compare themean arterial pressure values.As a result of our study, on patients performed open-heart surgery, we have noticedthat epidural anesthesia, which has been added to general anesthesia, limits the increase inIMA levels which are growing depending on the reperfusion injury after the periods ofACC is removed, reduces oxidant capacity at the same time increasing the antioxidantcapacity. In conclusion, in this kind of cases where reperfusion after ischemia exists, webelieve that epidural anesthesia added to general anesthesia reduces ischemia-reperfusioninjury and that its clinical use may be beneficial.Key Words: Cardiovascular Surgery, thoracic epidural anesthesia, ischemia reperfusioninjury.