Effects Of Propofol On Preservation Of Myocardial Function In Infants Undergoing Heart Surgery Using Cardiopulmonary Bypass

Part. 1,2With technique development of the cardiopulmonary bypass and the myocardial protection, now, little infants, including new born baby, with the congenital heart diseases are corrected or repaired by the open heart surgery with cardiopulmonary bypass, and postoperative outcome is good in the major infants' patients. However, the mortality of the heart surgical operation with cardiopulmonary bypass in baby's infant, especially the newborn, is still higher. The immature myocardial ischemia reperfusion or hypoxia/reoxgenation injury is the one of the factors primarily to cause death. Therefore it is very important how to prevent myocardial ischemia reperfusion injury in little infant or newborn undergoing cardiac surgery using cardiopulmonary bypass.Objective To investigate the effects of propofol on activities of serum lactate dehydrogenase (LI)H), creation kinase (CK) and super oxide dismutase (SOD) and expression of myocardial nuclear factor- k B (NF- k B) and intercellular adhesion molecule l(ICAM-l), and proinflammatory cytokines (IL-6, TNF- a ), cardiac function in infants undergoing open heart surgery using cardiopulmonary bypass.Methods Twenty infants with congenital heart disease, aged 1-9 years, ASA grade I-II, scheduled for elective open cardiac surgery, were randomly divided into control group (group I n=10) and propofol group (group II n=10). The patients were premedicated with intramuscularly morphine 0.1.kg-l and scopolamine 0.01 mg.kg-1.anesthesia was induced with midazolam 0.15 mg.kg-1, fentanyl 10 ug.kg-1 and pacuronium 0.1 mg.kg-1. Following induction with valium-fentanyl-pancuronium, in-group I 0.25%-2%enflurane was inhaled for maintaining anesthesia, and in-group II propofol at rate of 15mg-25mg. kg-1.h-1 was given intravenously. The patients were mechanically ventilated and Pet CO2 was maintained between 35-45 mmHg. left radial artery and right jugular vein were cannulated for MAP and CVP monitoring. ECG, SpO2 and PetCO2 were Continuously monitored during operation. The central venous blood samples were collected before operation (To), after beginning of operation and before CPB (T1), 25 min after aorta was cross-clamped (T2), 30 min after released of aortic cross-clamp (T3), 2h after discontinuation of CPB (T4) and 24h after operation (T5) to measure the activities of serum LDH, CK, and SOD and levels of cytokine (IL-6, TNF a ). At the time of plugging into superior vena Cana drain tube from right atrium and reperfusion 30 min, the myocardial samples were taken to investigate expression of NF-kB, ICAM-1.Results The serum LDH and CK activities increased significantly in group I, and SOD activity decreased significantly following ischemia and reperfusion (P<0.05 or 0.01); in group II the serum LDH, CK and SOD values changed insignificantly following ischemia reperfusion, LDH, Ck and values in group II were lower than in group I at corresponding times. (P<0.05 or 0.01), SOD activity in-group II increased significantly as compares with the control level at same times. Compared with group II, blood IL-6 and TNF a were significantly increased at T3 or T4 in group I (p<0.05). At the time of reperfusion 30min,densitometricvalues of myocardial NF- k B, ICAM-1 in two groups were obviously lower than those of pr-CPB (p<0.05), and that in-group I was significantly higher than that in-group II (p<0.05). The postoperative cardiac function recovered much better in-group II than in group I. Tracheal extubation was earlier in group II than that in group I.Conclusion Propofol can attenuate the degree of myocardial injury and improve cardiac function as well as allows earlier recovery in infants undergoing open heart surgery with CPB. the mechanism may be related to its action of reducing lipid per oxidation and inflammatory responding, inhibiting myocardial NF- kB, ICAM-1 expression.