The Protective Function Of Modified GIK On Important Viscera Of Cardiac Surgery Patients

BackgroudThe majority of cardiovascular diseases can be cured by relative operation, and theseoperations rely on the cardiopulmonary bypass technology (CPB), which is also calledextracorporeal circulation (ECC). For the vast difference between the pattern of bloodperfusion and the patterns of the body’s normal physiological condition exists andproduce strong stress response in the body. Although the CPB technology becomingmature, its shortage would lead to the important viscera damage, and affect patient’srecovery of postoperative function. For example, the body appears high blood glucoseand high insulin during CPB, but sensitivity of target tissue to insulin obviouslydecreased. Resulting in, putting down glucose utilization, eventually leading to acuteinsulin resistance (IR), causing the related viscera function impaired. So, avoiding the IRbecomes the hot point in protecting heart and important organ during the operation.Glucose, Insulin and Potassium chloride (Glucose-Insulin-Potassium, GIK) used in theheart for protecting perioperative myocardial has a history of more than50years, but itsclinical application effect is uncertain. Patients undergoing cardiac surgery as theresearch object in this research. Whether IR induced by CPB, modified GIK protection in the heart and important viscera were investigated in this study. Complications andmortality also considered.Objective1. To study whether the CPB heart surgery develops IR, and the function ofmodified GIK on IR.2. To investigate functional changes of important viscera under the CPB heartsurgery, and the role of modified GIK on these important viscera.3. To observed the incidence of Complications and mortality after CPB, andexplore the influences of modified GIK on prognosis.Methods(1)1000cases of patients who suffer from cardiovascular disease and need docardiovascular surgical treatment were selected in this part. According to the stochasticindicator, these patients were divided randomly in to2groups, they are GIK group497cases,503cases of control group (CON group).(2) Modified GIK (20%glucose750ml,regular insulin50u,10%potassium chloride45ml) was injected rightly in the patientsof GIK group after anesthesia through central vein with the speed of60ml/h. While inCON group, the lactic acid was treated in the same way.(3) Preoperative routine checkswere performed on all patients. Sufficient consideration to family members and patientsthemselves was given. The corresponding operation was implied according the standardprocess. Trial1: arterial blood samples was collected at different points in both twogroups: before surgery, CPB5min, open the ascending aorta5min, end of CPB,1h afteroperation, postoperative6h,12h,24h after surgery, postoperative taking48h. Bloodsugar, K+, the lactic acid level were measured in collected samples.20patients wererandomly selected from each group, Blood sugar and difference blood sugar value whichrepresents the quantity of glucose intake by myocardial were tested from extracted arteryand coronary sinus blood in the same point: after the inferior vena cava bypass, beforethe resistance closed of ascending aorta and after the ascending aorta open. Trial2: Respectively, before the surgery, postoperative24h and48h, venous blood sampleswere measured in many parameters: aspertate aminotransferase (AST), lactatedehydrogenase (LDH), creatine kinase (CK), creatine kinase isoenzyme (CKMB) andhydroxy butyric acid dehydrogenase (HBDH), alanine aminotransferase (ALT), bilirubin,urea nitrogen (BUN), creatine (CR) level; Prior to surgery, troponin I (cTnI) of venousblood samples was studied on postoperative6h,24h and48h; In24h before surgeryand postoperative7days, left ventricular ejection fraction (LVEF) was also measured.Trial3: At the beginning of entering the ICU after operation, mechanical ventilation timeand ICU treatment time, length of hospital stay were collected. The number of patientswith complication was recorded. Symptoms of complications include shock, centralnervous system dysfunction, occurrence of atrial fibrillation, renal replacement therapyafter surgery. Death cases were recorded before leaving hospital.Statistical AnalysisThe software SPSS16.0was used to analyze results. All the data were expressedas x±SD in normal distribution. Data was listed as median and interquartile spacing (M,IQR) in skewed distribution. The Mann-Whitney-u test was used to value thedifference between two groups from skewed distribution. Count data by chi-squareanalysis; The Mann-Whitney inspected ranked data. And statistical results statisticallysignificant.at P <0.05.ResultsTrial1: no significantly difference of Potassium concentration was observed in twogroups; Blood glucose and lactate levels after operation in patients of two groups withdifferent degree rise. The blood glucose levels in intraoperative GIK group was higherthan the CON group (P <0.05) at ascending aorta open5min, but still less than8mmol/L, and was significantly lower than CON group (P <0.05) at6h after surgery.Lactic acid levels of all patients stay in the normal state, and there was no statisticaldifference. Lactic acid levels of GIK group in postoperative especially in postoperative1hour12hours,6hours less than CON group (P <0.05). In GIK group, myocardial sugar intake was significantly higher than CON group at two points: before the resistanceclosed of ascending aorta and after the ascending aorta open (P <0.001).Trial2: theLVEF of GIK group was obviously higher than that of CON group (P <0.01)7d afteroperation; compared with CON group, AST, CK, LDH and HBDH, CKMB, cTnI at24hand48h after surgery of GIK group decreased significantly (P <0.05, P <0.01, P <0.001); meanwhile, ALT, BIL, BUN, CR in postoperative24h and48h of GIK groupreduced in different degree. But there was no significantly difference between the twogroups in Myocardial enzymes of on off-pump coronary artery bypass graftpatients.Trial3: Mechanical ventilation time and ICU treatment time significantly lowerthan CON group (P <0.05); Kinds of shock after the operation and atrial fibrillation wasreduced obviously in GIK group (P <0.05);There was no significant difference between two groups in the central nervous systemdysfunction, Acute renal failure line bedside continuous renal replacement therapy anddeath cases.ConclusionAcute IR can be induced by Cardiac surgery and CPB for their intense stimulation. Andacute IR would cause damage to the heart and other vital organs. Modified GIK canimprove perioperative blood glucose and potassium ions remain relatively stable, and canease the IR degree, you can also play a protective effect on the organ to a certain extent.Modified GIK treatment can reduce the postoperative complications of patients,improving the prognosis of patients.