Can lidocaine protect against cerebral dysfunction of patients with cardiopulmonary bypass surgery?

The objective of this study was to investigate whether intraoperative administration of lidocaine can reduce the incidence of cerebral dysfunction in patients undergoing cardiac surgery with cardiopulmonary bypass [CPB]. 60 patients scheduled for cardiac surgery with CPB enrolled randomly into 2 groups: control group and lidocaine group. They were subjected to the same methods of anesthesia, monitoring process and CPB, and myocardial preservation techniques, lidocaine group received of 2 mg/kg bolus over 5 minutes and then infusion of 4 mg/min until the end of operation. The control group received normal saline at the same volume, rate and time. A brief battery of neuropsychologic tests was obtained preoperatively and on the tenth postoperative day. Jugular bulb oxygen [SJVO[2]] and S100beta protein were determined at different measuring points. The incidence of postoperative cognitive decline was significantly less in lidocaine group. SJVO[2] was significantly reduced during rewarming, only in the control group. S100beta was significantly elevated 24hs after CPB in both groups. The elevation was more significant in the control group. The cognitively declined patients tended to have significant fewer years of education, significant longer cross clamp time, longer CPB time, longer time to recovery and to extubation and higher S100beta. S100beta 24 hours after the bypass, was found in significant correlation with aortic cross clamp time, CPB time, time to recovery and to extubation, besides performance in Rey AVLT and Trial Making tests. We can conclude that lidocaine has a protective effect against cerebral insult of CPB

effect of perfusion pressure during cardiopulmonary bypass on gastric mucosal pH

The objective of this prospective randomized study was to investigate the effect of high and low perfusion pressure during cardiopulmonary bypass [CPB] on the gastric mucosal pH [pHim]. The study was carried out on 30 patients scheduled for elective valve replacement surgery and allocated randomly into one of two groups: group I [n=14] managed by perfusion pressure of 70-90 mmHg during CPB and group II [n= 16] managed by perfusion pressure < 60 mmHg during CPB. All patients were subjected to the same method of anesthesia, monitoring, anticoagulation and myocardial protection. ABG, PCO[2] [R-a], pHim were recorded before, during, at the end of and one hour after CPB. The results of this study revealed that in contrast to high perfusion pressure low perfusion pressure was associated with significant gastric mucosal acidosis during and after CPB. So we can concluded that the use of perfusion pressure >/= 70 mmHg can prevent or attenuate gastric mucosal acidosis during open cardiac surgery

Comparison between clonidine and verapamil as additives to local anesthetic for intravenous regional anesthesia

This study compared the effect of addition of clonidine or verapamil to 0.5% lidocaine for intravenous regional anesthesia [IVRA] on the onset of sensory and motor block, duration of postoperative analgesia, recovery of sensory function and hemodynamic response to tourniquet. Sixty patients scheduled for minor orthopedic surgery in the hand and forearm were randomly allocated into one of three groups. All patients received 40 ml of 0.5% of lidocaine together with 5 ml of an additive. The additive was saline in group A, clonidine 2 mug kg -1 in group B and 5 mg verapamil in group C. The results revealed that the onset of complete sensory block proved to be significantly faster in patients received clonidine and verapamil than the control group. The return of sensory function was significantly slower in clonidine group and verapamil group, the tourniquet pain scores were significantly better in clonidine and verapamil groups and the hypertensive response to the tourniquet was attenuated in both groups