| Objective: To compare the pharmacodynamic differences of common carotid artery administration with ear edge vein administration of propofol and fentanyl in rabbits.The direct injection of drμgs into one of the main arteries supplying the encephalon has been largely utilized in experimental neurophysiology in recent years.Compared with intravenous infusion drμgs,there are four main superiority of in tracarotid infusing drμgs:(1)the rapid effect of infusing drμgs; (2)the strong therapy purpose;(3)the good therapy effects and (4)the minor general side effete,et al.The drμgs used via intracarotid were multiformities such as radiopaque materials of 99mTc and 133Xe,calcium ion channel blockers of verapamil,thrombolytic drμgs of urokinase , hormone of Prednisolone,anesthetic drμgs of amobarbital,cardiazol,megimide and chems drμgs of cisplatinum and so on. It has been widespread used of intracarotid infusing drμgs in the therapy territory of cerebral infarction,functional Ioealization of cerebral region,brain protection and the therapy of brain tumor et al.As we know that the brain is intravenous anestheties'target organ. Therefore,can we anesthetize patients via intracarotid infusing anesthetics,then? Whether the benefits of intracarotid infusing drμgs are better than intravenous infusion or not? To our knowledge,there is no intracarotid infusing anestheties for general anesthesia purpose in clinical work.First,to compare the effects of common carotid artery and ear edge vein administration of propofol to compound fentanyl for electrocerebral silenee (ES) on circulatory and respiratory function and the dosage of propofol and fentanyl required during ES in rabbits,we plan to discuss the benefits of common carotid artery infusing anesthetics. Secondly to observe the possibility injuries of vascular tissues in the propofol and fentanyl filling encephalic regions and to investigate the safety of propofol and fentanyl direct infusion via common carotid artery at the levels of cell for general anesthesia purpose in clinical operation.The research consists of the following three aspects: first, comparison of the pharmacodynamics difference between common carotid artery and intravenous propofol and fentanyl in rabbits;second,the influence on the rabbit aortic tissue when continuely infusion propofol via common carotid artery.Methods: The experiments were performed on 60 adult rabbits either sex. These animals were divided into two groups randomly of each 30, including Group V (intravenous adminis- tration of fentanyl group, n = 30) and Group A (the common carotid arterial administration of fentanyl,n=30).Then each group was divided into two subgroups:Group Vv n=15,Group Va n=15,Group Av n=15 and Group Aa n=15. All rabbits were anaesthetized by injecting katamine and common carotid artery was isolated.Then,Y-type vein needles were implanted in every rabbit's common carotid and ear edge vein and heparinized. We'll recorded the outcomes,including the time of conscious- ness loss and recovery,of consciousness and the dose of propofol and fentanyl,and observed the changes of hemodynamic and re- spiretory in rabbits at the same depth of anesthesia(ECG0~3Hz). They were all recovered.Animals were executed after experi- ment and the common carotid artery tissue of infusing drμgs were obtained and detected by light microscope.Results : The dose of common carotid arterial propofol was significantly less than of intravenous propofol at the point of consciousness,10s and 60min of EEG=0~3,about 1/3~1/2 that of intravenous propofol dose required.Compared with baseline values,the mean arterial pressure and respiration rate decreased transiently during ES with common carotid artery propofol.In contrast,intravenous propofol resulted in systemic hypotension and severe respiratory depression.The effect of intracarotid propofol is minor than carotid artrery.As for loss of con- sciousness,carotid artery propofol were more quickly than intra- venous infusion.The endangium of control group was smooth and glossy and the coloration was uniform. So does the experi- ment group.There is no any acute injury to befound by light mi- croscope.Conclusion: The different methods that propofol and fentanyl were administrated via the ear edge vien or the common carotid artery,can achieve the purpose of the maintenance of general anesthesia in rabbits.Comparing with drμg infusion via the ear vien,infusion of propofol and fentanyl via the common carotid artery is more advantageous in some aspects,such as rapid anes- thesia inducation and recovery,less medication, smaller impact on the hemodynamic and respiratory,no vascular injury.The infusion method that both propofol and fentanyl were adminis- trated via common carotid artery is ideal anesthesia modalities, which be due to the least amount of narcotic drμgs,the most rapid inducion and recovery, the most minor change of hemody- namic and respiratory . |
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