The Protective Effects Of Different Cardioplegias On Immature Pigs Myocardium

Objective:To assess the protective effects of the STH solution,HTK solution and cold blood solution on immature pigs myocardium.Methods:Twenty-one immature pigs (4.5-8kg) were randomized into three groups. In group A was perfused with STH solution, group B with cold blood solution, group C with HTK solution.The pre-washed liquid selected colloid, crstalloid solution(acetate Ringer’s solution,sodium bicarbonate)and blood. In the CPB,hold systemic hypothermia and moderate hemodilution.The three groups using compound anesthetic techniques,after anesthesia and heparinized, cardiopulmonary bypass was instituted, and ascending aorta was clamped. Then antegrade perfuse the cardioplegia in the aortic root. STH solution(4℃) was perfused about20ml/kg the first time,after that it was done about ten mililiter per kilogram every thirty minutes until aotic crossclamp was removed,and the pressure80-100mmHg.The method of cold blood solution(4-6℃) was same with the STH solution.HTK(4℃) solution was perfused about40ml/kg during five to seven minutes and one time was enough.In this study,the three group using deep hypothermia(nasopharyngeal temperature:20-25℃) and low flow cardiopulmonary bypass during the time of the ascending aorta was clamped. Intraoperative attention to the left ventricular drainage was adequate to avoid heart postings.Before stopping the CPB,full ultrafiltration,make the HCT restored to about30%.According to the blood gas results adjust the PH and electrolyte in time.After the heart successfully restored beating,routinely given to various drugs. Then rewarming and weaning from the CPB, observed2hours. At last, the left ventricular tissue was observed by electron microscope. Recorded some indexs such as the CPB time(min),the assist circulation time(min),the auto-beating rate(%),the dose of inotropic drugs(Dopamine and Dobutamine).Get4ml blood sample in different times such as T1-T6,1ml for blood gas analysis,another3ml centrifuged(3000rev/min,15min)within2h, then extracted the plasma and stored at refrigerator (-80℃) Measured the serum levels of cardie troponinI(cTnI), cardiac troponinT(cTnT) and creatine kinase MB(CK-MB).Analysis of Statistics:statistically analysis all the data with SPSS17.0.If P<0.05means that the different of data has significant statistically.Results:1. The pH、PO2、PCO、K+、Ca2+、HCT and Glu at each time point were not statistically different (P>0.05).At T2,the Na+concentration of group C is lower than group A and B(P<0.05);After T4,the Lac gradually increased(P>0.05),group B and C is lower than group A(P>0.05);at T5,the base excess of group C compared with group A significant difference (P>0.05),at T6,the base excess of group B and C compared with group A significant difference (P>0.05)2. The serum concentration of cTnI, cTnT and CK-MB were all no significantly before the CPB(P>0.05).At T2-T6, the serum concentration of CK-MB in group B was significantly lower than it in group A(P<0.05), At T4-T6, the serum concentration of CK-MB in group B was significantly lower than it in group A(P<0.05), and there was no significant difference in group B and group C (P>0.05).At T2-T6, the serum concentration of cTnl in group B and group C was lower than it in group A(P<0.05), and there was no significant difference in group B and group C (P>0.05).At T2-T6, the serum concentration of cTnT in group B was significantly lower than it in group A(P<0.05), At T2-T4, the serum concentration of cTnT in group B was significantly lower than it in group A(P<0.05), and there was no significant difference in group B and group C (P>0.05). The does of inotropic drugs(Dopamine and Dobutamine)in group B and group C were significantly lower than those in group A(P>0.05),and there was no significant difference in group B and group C (P>0.05)3. Electron microscope show:the mitochondria in group B and group C were better than that it in group A(P<0.05).Conclusions:Compared with STH solution, HTK solution and Cold blood solution could provide satisfactory protection for the immature pig myocardium.