Study The Effect Of Epidural Block During Propofol Target Controlled Infusion General Anesthesia Induction Period

At present,people usually think that general anesthesia can only inhibit the projected systems of the cerebral cortex,general anesthesia can not effectively block the conduction from surgery regional noxious stimulation to the sympathetic nerve of junior center. General anesthesia can make sympathetic-adrenomedullin excited and caused the catecholamine secreting increased,the consequences are hypertension, rapid heart rates, leading or increasing myocardial ischemia. Simply,epidural anesthesia can block the spinal nerve directly and block the importation at the spinal level,but the drawback is the sober during the peacekeeping operation period,the difficulties of respiratory management,not enough blocked plane and a strong stretch reflex. In the epidural anesthesia combined with general anesthesia,epidural anesthesia can block noxious stimulation which conduction is afferent, it can suppress the effect of the stress response, so that the doses of entire anesthetics and muscle relaxants reduced, it has more forte such as quickly regained consciousness,rapid postoperative recovery,the postoperative epidural analgesia and so on. General anesthesia can effectively suppressing stress response which caused by vagus and psychological stress, so it can achieve the purpose which is the endocrine stability and contribute the smooth of hemodynamics.Furthermore, according to the literature reports, the supraglottic exposure by laryngoscopy and tracheal intubation is one of the strongest perverse incentives during the general anesthesia, it makes sympathetic-adrenomedullin excited and caused the catecholamine secretion increased, so led to a series of cardiovascular responses. The epidural anesthesia in the mid-abdomen can be effective in blocking the sympathetic excitatory spread, so making the catecholamine secretion of adrenal medulla cells inhibited, thus reducing the stress response during the endotracheal intubation.But on the other hand, it is reported that the epidural anesthesia combined with general anesthesia during the induction period can cause a serious sinus bradycardia and hypotension, this had led to a epidural anesthesia combined with general anesthesia for the application concerns and make a limited application at a large extent. At present the biggest advantages of epidural anesthesia during the anesthesia induction period is the prevention of tracheal intubation response role.The most possible mechanism of new epidural anesthesia combined with general anesthesia is blocking the sympathetic nerve which dominate by the adrenal gland,it can obviously suppress the sympathetic-adrenergic system and the excretion of catecholamine.On the other hand,because of the sympathetic disrupted extensively,the capacity blood vessel dilated at the blocked region,the pre-load reduced,the systolic blood pressure dropped,at the same time,also making the deputy sympathetic hyperactivity,the heart rate slowed,this inhibition of cardiovascular partly offset the severe cardiovascular response during tracheal incubation. Propofol is one of the most commonly used drug which is used to clinical anesthesia,because it can significantly reduce the stress response caused by the endotracheal intubation, the possible mechanism is by inhibiting sympathetic activity and expanding the blood vessels for countering the stress response from the cardiovascular,it has quickly speed during the induction of general anesthesia and the results is reliable. Some literature reports the propofol can cause significant hypotension during the period of epidural anesthesia combined with general anesthesia,this has made the people concerns about the conventional application of epidural anesthesia. However, with target-controlled infusion technologies emerge,we chose the way of target-controlled infusion of propofol,because target-controlled infusion can make the drug concentration at the effects of concentration room rapidly,reducing the total drug doses,making the hemodynamic more stable and will be more suitable for epidural anesthesia of the induction period. So,this article is mainly discuss about the hemodynamic changes under the propofol target-controlled infusion of epidural anesthesia,aiming at finding a more secure and reasonable induction methods for the epidural anesthesia combined with general anesthesia.Objective: To prevent the cardiovascular effects of endotracheal tube, we use general anesthesia combined with epidural block induction method, observe hemodynamics in epidural block combined with Propofol target controlled infusion general anesthesia, approach the effect and clinical significance of 1% lidocaine. Method: select 31 ASA gradeⅠ~Ⅱpatients, Operation on mid-abdominal region, divided into two groups randomly, accept both Epidural puncturation and general anesthesia induction. Inpouring 1%lidocaine to the cavitas epiduralis in group EG, and inpouring sodium chloride, 0.2ml/kg in group G. 15minutes later target controlled infusion Propofol, installate target level on 3μg/ml, then do general anesthesia induction with sulfentanyl and Vecuronium Bromide followed by tracheal intubation. Record SBP,DBP,MAP,HR,RPP,BIS and effect concentration of propofol.Result: Two group's SBP,DBP,MAP,HR and RPP gradually degrade but at the tracheal intubation. moment,all index average of group G significantly rise up, there is a significant statistical difference. (P<0.01). There is no statistical difference. in group E. Consciousness extinction time, group EG is significantly shorter than group G (P<0.01); effect concentration of propofol at the time of unconsciousness, EG is significantly lower than group G.Conclusion: 1%lidocaine not only shorter the induction ,but also hold-back the change of hemodynamics and myocardium hypoperfusion caused by tracheal intubation, but not increase the rate of low blood pressure and bradycardia caused by target controlled infusion of Propofol.