Objective To assess the cerebral protective effects of different doses of propofol during mild hypothermic cardiopulmonary bypass (32℃-35℃) .Methods Thirty consecutive ASA Ⅱ-Ⅲ patients aged 18-50 years, undergoing elective cardiac surgery under mild hypothermic CPB were randomly divided into 3 groups: in group Ⅰ and Ⅱ the patients were given a bolus of propofol 1 mg kg-1 at the beginning of CPB followed by propofol infusion at a rate of 3 mg ? kg -1? h -1 (group Ⅰ ) or 6 mg? kg-1 ?h-1 (group D ) till the end of CPB and in group Ⅲthe patients received midazolam infusion at 0.2 mg? kg-1 h-1 instead of propofol. Anesthesia was induced with intravenous midazolam 0.15 mgkg-1 ,fentanyl 5 ?g kg-1 and vecuronium 0.1 mg? kg-1 .After tracheal intubation fentanyl 30-50 ?g kg-1 was infused during CPB and muscle relaxation was maintained with intermittent iv boluses of vecuronium. Surgery was performed with mild hypothermic CPB(32℃-35℃ ) .Arterial blood pH and PaCO2 were maintained within normal range and MAP was maintained at 50-80 mm Hg during CPB. Hematocrit was maintained at 25%-30% .Internal jugular vein(IJV) was cannulated and the catheter was advanced retrogradely till jugular bulb. Naso-pharyngeal temperature was monitored. Blood samples were taken simultaneously from artery and UV befor CPB (A) ,when mild hypothermia was being stably maintained(B) ,when the patients were rewarmed to 361 (C)and 30min(D),4-6 h(E)and 24 h(F) after discontinuation of CPB, for determination of cerebral oxygen metabolism and balance, cerebral lactate production (CLP), blood malondialdehyde (MDA) and superoxide dismutase (SOD) levels. CLP was calculated from arterial-cerebral venous blood lactate difference /arterial blood lactate concentration. Lactate oxygen index (LOI) was calculated from arterial-cerebral venous blood lactate difference /arterial-cerebral venous blood O2 content difference.Results In group I (low propofol dose) 30% patients developed cerebral O2 inbalance during rewarming but blood MDA, CLP and LOI were decreased. In midazolam group (group Ⅲ) cerebral O2 balance was improved but there was no depression of blood MDA, CLP and LOI. In groupⅡ (high propofol dose) cerebral oxygenation was improved and blood MDA level, CLP and LOI were significantly decreased.Conclusion The study shows that propofol infusion at a rate of 6 mg?kg-1? h-1 during CPB can improve cerebral oxygenaton, inhibit blood MDA level, CLP and LOI, and plays a role in the cerebral protection during cardiac surgery with CPB, but more vasoconstrictors are needed.

Objective It was estimated that about 70% patients suffered from mild brain function disturbances after cardiac surgery with CPB Methods for early detection of brain injury after CPB in current use like EEG, transcranial Doppler, CT, MRI are expensive and not sensitive It was repored that combined assays of S 100 protein and NSE were conducive to early detection of brain ischemic injury and prediction of the prognosis The purpose of this study was to assess the changes in cerebral blood S 100 protein and NSE levels during and after open heart surgery with mild hypothermic CPB Methods 15 consecutive ASA Ⅱ Ⅲ patients undergoing elective open heart surgery under CPB were studied Aortic cross clamping time was 30 60 min and CPB time was less than 120 min Patients with hypertension and neurologic or endocrine diseases were excluded Anesthesia was induced with midazolam 0 15mg/kg, fentanyl 5?g/kg and vecuronium 0 1mg/kg Fentanyl 30 50 ?g/kg was continuously infused after tracheal intubation and during CPB Vecuronium was given intermittently to maintain muscle relaxation Midazolam was infused at 0 2mg?kg -1 h -1 during CPB Temperature was reduced to 32℃ 35℃ during CPB Aterial blood pH and PCO 2 were maintained within normal range and Hct between 25% 30% during CPB Internal jugular vein was caunulated and the catheter was advanced retrogradely until jugular bulb Jugular venous blood samples were taken for determination of S 100 protein and NSE content before CPB (A),when mild hypothermia (32℃ 35℃ ) was steadily maintained (B), rewarming to 36℃ (C), 30 min (D),4 6h (E) and 24h (F) after termination of CPB Results (1) After institution of CPB, S 100 protein level increased significantly (P

Objective To evaluate the efficacy and safety of 0.75% ropivacaine versus 0.75% bupivicaine for combined spinal and epidural anesthesia(CSEA) for cesarean section. Methods Forty primiparae(ASA Ⅰ-Ⅱ) scheduled for elective cesarean section were divided into two groups: ropivacaine group received 0.75% ropivacaine 1 .2-1 . 4ml(9-10. 5mg) for spinal anesthesia and bupivicaine group received same amount of 0.75% bupivicaine. During operation when spinal analgesia was inadequate, 1.6% lidocaine was supplemented via epidural catheter. Blood pressure , heart rate and SpO2 were monitored. Sensory block(pin prick), motor block(modified Bromage scale), quality of analgesia and relaxation of abdominal wall were assessed. Apgar score of the neonates and umbilical artery blood gas as well as side effects were recorded. Results There was no significant difference between the two groups in age, height, body weight of the patients and duration of operation. The height of block was comparable between the two groups but the onset time was longer and duration of block was shorter in ropivacaine group. Analgesia and muscle relaxation were satisfactory and Apger score was 10 at 1 mm and 5mm in both groups. Blood gas values were within normal range in both groups. Motor block was weaker with ropivacaine than that with bupivacaine(P

Objective:To observe acid-base and biochemical changes in clinical orthotopic liver transplantation with veno-venous bypass.Method,Seven patients receiving orthotopic liver transplantation, veno-venous bypass was undergone in anheptic phase.The acid-base and biochemical parameters were monitored during operation. Result:Compared to preoperation,pH decreased a little in each phase,BE and SBC slightly decreased 60 min following bypass and during skin closure. Compared to before bypass,pH had no changes during bypass and new liver phases. The serum Ca~(2+) level decreased and serum glucose level elevated in each phase,The temperature gradually decreased during operation. The serum K~+ level was transiently elevated from 3.17mmol/L to 3.53 mmol/L early after the heptic revascularizaton. Conclusion:With the application of the veno-venous bypass technique,the hazard of acid-base and biochemical changes can be reduced during orthotopic heptic transplantation.