ABSTRACT
Objective:To investigate the effects of high thoracic epidural anesthesia (HTEA) on the cerebral blood flow (CBF) and hippocampal apoptosis-related proteins Bcl-2 and Bax during global cerebral ischemia and reperfusion (GCI) in rats.Methods:Fifteen-minute global ischemia was established by 4-vessel occlusion and epidural catheterization was performed through T4-5 intervertebral spaces in adult male Wistar rats.According to the different drugs infused into the epidural space,the rats were randomly divided into four groups:Sham group (0.9 ％ NaC1),Sham-HTEA group (0.25 ％ bupivacaine),GCI group (global cerebral ischemia,0.9 ％ NaC1) and HTEA group (global cerebral ischemia,0.25 ％ bupivacaine).And 0.25 ％bupivacaine or 0.9 ％ saline (20 μL·h-1) was infused continuously to the thoracic epidural space from 15 minutes before ischemia to 24 hours after reperfusion.Mean arterial pressure (MAP),heart rate (HR) and cerebral blood flow (CBF) were determined until 2 hours after reperfusion,and the hippocampal Bcl-2 and Bax proteins at 24 hours after reperfusion were examined by Western-blot.Results:Compared with the GCI group,HTEA group has no significant difference on MAP and HR during ischemia and 2 hours after reperfusion,andcompared with the Sham group,MAP in GCI group increased in ischemia 0 min and decreased in reperfusion 0 min.The CBF in HTEA group was significantly lower than that in GCI group (123.1％± 35.2％ vs 177.5％± 32.4％,P＜0.01) in reperfusion 10 min,and higher than that in GCI group during the hypoperfusion of 60 to 120 minutes after reperfusion (P＜0.05),and the ratio of Bax/Bcl-2 in hippocampus was significantly decreased in HTEA group 24 hours after reperfusion (P＜0.01).Conclusions:Continuous HTEA infusion of 0.25 ％ bupivacaine 20 μL ·h-1 could maintain the hemodynamic stability,and improve the CBF of hypoperfusion period in rats,as well as reduce the ratio of Bax/Bcl-2 at 24 hours after reperfusion.
ABSTRACT
Background : During off pump coronary artery bypass surgery (OPCAB) to provide adequate myocardial protection cardiac anaesthesiologist frequently needs to use various pharmacological intervention rather than physiological manipulation. This is challenging to overcome the adverse effects of the various drugs. During the past few years, high thoracic epidural anaesthesia (HTEA) as an adjunct to general anaesthesia has become more popular and has been shown to be potentially beneficial in patients with coronary diseases. It provides good protection from stress response, ensures hemodynamic stability, improves distribution of coronary blood flow and reduce demand for oxygen and perioperative arrhythmia. Objective : This study has been undertaken with a view to compare the requirement of intraoperative cardiac drugs between HTEA with General Anaesthesia(GA) and GA alone. Methods: Prospective, randomized case control study was undertaken in sixty patients, without having left main coronary disease, left ventreicular ejection fraction <35% or contraindication of regional anaesthesia scheduled for OPCAB. They were divided into two groups, thirty in each group. Group A patients received GA alone and group B patients received high thoracic epidural anaesthesia with GA. Requirement of drugs (antiarrhythmic, inotropes, vasoconstrictor, vasodilators,Esmolol e.g.) during operation were recorded. Results: Dopamine was needed in 27(90.0%)patients in group A and 11(36.7%) patients in group B, adrenaline was used in 15(50.0%)patients in group A and 4(13.3%) in group B; Dobutamine was used only in 5(15.0%) patients in group A and ephedrine was required only in 2(5.0%) in group B. Regarding the Antiarrhythmic drugs, Lignocanie, Amiodarone and DC Shock was required only in 17(55.0%), 12(40.0%) and 5(15.0%) patients respectively only in group A. In vasodilators group, Nitropruside was used in 5(15.0%) and 1(3.3%) patients in group A and group B respectively. Esmolol was used in 17(55.0%) patients in group A and 1(3.3%) in group B. Significant (p<0.05) difference were found in use of all drugs between two groups except Ephedrine and Nitropruside . Conclusion: The anaesthetic technique HTEA with GA required minimum intra operative cardiac drugs than GA only.
ABSTRACT
Background: In Bangladesh, although OPCAB surgery are done, the number of centers are limited and as a result, studies on this subject are also few. Consequently, there are no exclusive data regarding the best anaesthetic technique in the context of superior haemodynamic stability. This study has been undertaken with a view to find out whether a combined HTEA with GA (TIVA) is safe and more efficient in providing overall cardiovascular stability. The common challenges for the cardiac anaesthesiologist during off pump coronary artery surgery (OPCAB) to maintain optimal cardiovascular parameters such as heart rate, blood pressure, CVP and arrhythmias during the different stressful surgical events and multiple cardiac manipulations, providing adequate myocardial protection, are sometimes difficult. This study has been undertaken with a view to find out whether a combined HTEA with TIVA is safe and more efficient in providing overall cardiovascular stability. Method: Sixty patients aged between 40-70 years, without having any coagulopathy disorder , any emergency surgery or left main disease scheduled for CABG on beating heart were enrolled in prospective, randomized observational comparative study. Patients were divided in two groups. In group A patients received TIVA alone and in group B patients received high thoracic epidural anaesthesia with TIVA. The parameters including heart rate , SPO2 , CVP , arterial blood pressure , rate pressure product , arrhythmia in ECG, were recorded before induction, during induction , intubation and during different events of the surgery ( skin incision, sternotomy, pericardiotomy, coronary artery anastomosis with graft , sternum closure and wound closure) was recorded. Result: Significant per-operative mean heart rate changes were observed all the events except at wound closure and during anastomosis with D1/D2 and the mean difference of mean of mean arterial pressure at intubations, skin incision, sternotomy, pericardiotomy, during anastomosis of distal end of the graft with RCA, PDA, LCX and D1/D2 were observed statistically significant (p<0.05) . No incidence of different arrhythmia occurred in group B, premature ventricular complex (PVC) was statistically significant (p<0.05) between two groups. Conclusion: HTEA with TIVA appeared to be most comprehensive, allowing for revascularization of any coronary artery, providing good cardiovascular stability during OPCAB.