异丙酚对心肌缺血再灌注兔胃粘膜pH值的影响

Effect of propofol on gastric intramucosal pH after myocardial ischemia-reperf usion in rabbits

目的 观察兔心肌缺血再灌注后胃粘膜pH值(pHi)的变化,并探讨异丙酚对心肌缺血再灌注后兔内脏器官微循环灌注的影响。方法20只健康家兔,麻醉后随机分为生理盐水对照组(A组)及异丙酚组(B组,术中5mg·kg-1·h-1)。于基础状态(T0),心肌缺血60min(T1),再灌注后60min(T2)、90min(T3)和180min(T4)分别记录收缩压(SBP)、舒张压(DBP)、心率(HR)和pHi值。结果 两组动物5个不同时点的HR、SBP、DBP无显著差异(P>0.05)。两组动物缺血及再灌注后HR、SBP、DBP均有显著性下降(P<0.01)。pHi变化:与A组相比,B组动物T3点pHi值较低(P<0.05);组内,两组动物缺血及再灌注后pHi值均有显著性下降(P<0.01)。两组动物收缩压(SBP)及HR与pHi的变化均具有显著意义的相关性。结论 兔心肌缺血再灌注后,pHi持续显著降低,且pHi与血流动力学变化趋势一致,具有显著意义相关性。兔缺血再灌注期间,5mg·km-1·h-1异丙酚持续静注并不能改善胃肠道微循环灌注,甚至有可能加重胃肠道的低灌注及氧合障碍。

Objective To investigate the changes in gastric intramucosal pH (pHi) and the effect of propofol on microcirculatory perfusion after myocardial ischemia-reperfusion injury in rabbits. Methods Twenty healthy adult rabbits of both sexes, weighing 2.0-2.7kg were randomly divided into two groups: A control group (n=10) and B propofol group (n = 10) . The animals were anesthetized with 2% sodium pentothal iv. Anesthesia was maintained with intermittent iv boluses of fentanyl and vecuronium. The animals were tracheotomized and mechanically ventilated during fluid and propofol infusion. PaCO2 was maintained at 35-40 mm Hg. Right internal jugular vein was cannulated for fluid and propofol infusion. Left carotid artery was cannulated for BP and HR monitoring and blood sampling. TRIP tonometry catheter (14F) was placed in the stomach. Lactated Ringer's solution was infused at 6-8 ml-kg-1 h-1 during experiment. In group B propofol was infused at 5mg-kg-1-h-1 when BP and HR were stabilized for 10 min, chest was opened and heart exposed. Left anterior descending artery (LAD) was tied for 60 min and then released for reperfusion. Hemodynamics and pHi were measured before myocardial ischemia (T0) , 60 min after myocardial ischemia (T1), 60 min (T2), 90min (T3) and 180min (T4) after reperfusion was started. Results There was no significant difference in BP and HR from T0 to T4 between the two groups. pHi decreased significantly after myocardial ischemia-reperfusion injury in both groups. pHi was significantly lower at T3 in propofol group than that in control group (P<0.05) . There was positive correlation between the changes in systolic blood pressure (SBP) and pHi. Conclusion pHi decreases significantly after myocardial ischemia-reperfusion injury in rabbits. The changes in pHi are positively correlated with the changes in hemodynarnics. Propofol infusion at 5mg-kg-1-h-1 can not improve gastrointestinal micro-circulatory perfusion.