Objective To investigate the effects of mild hypothermic cardiopulmonary bypass(CPB) on bax and bcl-2 protein expression and neuronal apoptosis in hippooampus CA1 region in rats. Methods Healthy male SD rats weighing 380-420g were randomly divided into 3 groups: (1)post-CPB 1h group (n=6); (2) post-CPB 6h group (n=6) and (3) sham CPB group(n=5). The animals were anesthetized with intraperitoneal fentanyl 150?g?kg~(-1), midazolam 1 mg?kg~(-1) and vecurunium 0.1 mg?kg~(-1), intubated and mechanically ventilated. Left femoral artery was cannulated for heparinizafion, BP monitoring and blood sampling. Artery in the tail and right jugular vein were cannulated for CPB. The animals in group 1 and 2 underwent 2 h mild hypothermic (26-28℃) CPB at a flow of 160 ml?kg~(-1)?min~(-1). 1h(group 1) and 6h(group 2) after CPB 4% polymerized formaldehyde was injected via the artery in the tail. Brains were immediately removed. Bax and bcl-2 protein expression in hippocampus CA1 region was determined by immuno-histochemistry method and neuronal apoptosis by TUNEL technique. Ultrastructural changes were examined with electron microscope. Results (1)Bax and Bcl-2 protein expressions were significantly higher in group 1(1h after CPB)than in sham CPB group. Bax protein expression was significantly higher but bcl-2 protein expression was significantly lower in group 2 than in group 1. bax/bcl-2 ratio in group 2(at 6h after CPB)was significantly higher than that in group 1(at 1h after CPB). (2) Neuronal apoptosis was significantly increased in group 1 and 2 compared to sham CPB group. (3) Electron microscopy showed that some mitochondria were moderately or severely swollen with vacuolizafion and decreased number of mitochondrial at 1h after CPB and at 6h after CPB there was shrinkage of neuronal cells with irregular shape of nucleus, notches in nuclear membrane and margination of nucleoli. Conclusion CPB induces upregulation of both bax and bcl-2 protein expression with predominance of the pro-apoptotic gene Bax leading to increased neuronal apoptosis, indicating that CPB can cause brain injury.

Objective To investigate the safety of inhalation of isoflurane (ISO) or sevoflurane (SEVO) mixed with nitric oxide (NO) during mechanical ventilation.Methods Thirty-six healthy piglets of both sexes weighing 7-11 kg were randomly allocated to one of 6 groups ( n = 6 each): (1) control group was mechanically ventilated with O2; (2) NO group inhaled 20 ppm NO; (3) ISO group inhaled 1.3 MAC isoflurane; (4) ISO + NO group 1.3 MAC isoflurane + 20 ppm NO; (5) SEVO group inhaled 1.3 MAC sevoflurane and (6) SEVO + NO group inhaled 1.3 MAC sevoflurane + 20 ppm NO. The animals were mechanically ventilated with IPPV (VT 10 ml?kg-1 , RR 30-40 bpm, I: E 1:2) for 4 h in the all 6 groups. The animals were premedicated with atropine 0.02 mg?kg-1 i.m. . The Ⅳ line was established for fluid and drug administration. An additional dose of ketamine 10 mg?kg-1 was given i.v. before tracheostomy. 4F S-G catheter was placed in pulmonary artery via right internal jugular vein for hemodynamic monitoring. Femoral artery was cannulated for BP monitoring and collection of artrerial blood samples. MAP, HR, CVP, right ventricular pressure (RVP), PCWP, MPAP and total compliance of respiratory system (Crs), Paw, VT and PET CO2 were recorded before (T0 ) and at 1, 2, 3, 4 h of ventilation (T1-4). Blood samples were taken at T0 , T2 and T4 for determination of Met Hb and NO2- /NO3- . The animals were killed at the end of 4 h mechanical ventilation and the lungs were removed for determination of wet/dry(W/D) lung weight ratio, broncho-alveolar lavage fluid (BALF) and microscopic examination. BALF was collected for determination of surface tension and concentrations of saturated phosphate (DSPC) , total phosphate (TPL) total protein (TP) and white cell count. Results Crs was significantly decreased at the end of ventilation (T4 ) as compared with the baseline (T0) in group 3,4,5 and 6, while there was no significant change in Crs in group 1 and 2. DSPC/TP was significantly lower in group 3,4,5 and 6 than in group 1 ( P 0.05 ) . Conclusion 1.3 MAC isoflurane or sevoflurane mixed with 20 ppm NO can be used safely during mechanical ventilation.

Objective To evaluate the accuracy of a new generation bioimpedance cardiac output monitor as compared with thermodilution and end expiratory CO 2 techniques Methods Sixteen patients (14 males, 2 females) aged (58?12) years undergoing elective coronary artery bypass (CAB) surgery were studied Cardiac output was measured after CAB surgery in ICU using a new generation bioimpedance cardiac output monitor(Rheo Bioimpedance Hemodynamic monitor) and conventional thermodilution technique in 16 patients and end expiratory CO 2 technique in 10 patients Cardiac output was also measured with Rheo Bioimpedance Hemodynamic monitor in 200 healthy volunteers consisting of equal numbers of male and female The volunteers of each sex were further divided into 5 equal groups of 20 each: (1)20 29 years, (2)30 39 years, (3)40 49 years, (4)50 59 years and (5)60 70 years Results Cardiac outputs measured by bioimpedance and thermodilution techniques were well correlated (r=0 83) and there was also a good correlation between cardiac outputs measured by bioimpedance and end expiratory CO 2 techniques(r=0 88) Cardiac out measured with Rheo Bioimpedance Hemodynamic monitor in 200 healthy volunteers showed that there was a significant difference in cardiac output between 60 70 years age group and the other age groups in both male and female Conclusions Cardiac output and other hemodynamic parameters measured with the new generation bioimpedance hemodynamic monitor are accurate and can be used for preoperative cardiovascular function evaluation and postoperative monitoring of dynamic changes in circulatory function

OBJECTIVE:To build up a method of determining the concentration of midazolam in plasma by RPHPLC-UV detection.METHODS:The separation was carried out by a reversed-phase Hypersil ODS column(250mm?4.0mm,5?m) with a mobile phase consisting of methanol-acetonitrile-0.02mol/L potassium phosphate buffer(pH 7.4) (65∶25∶10,V/V).Mida_zolam was extracted from alkalinizing plasma and soluted in the mobile phase then detected at 221nm.RESULTS:The calibration curve had the fine linearity in the concentration range 50～1 600ng/ml(r=0.9 999).The detection limit was 2ng/ml.The absolute recovery was 90.8%～95.4%,the relative recovery was 99.3%～101.3%.The within-day and between-day precision(CV%) was 1.94%～5.16%,3.00%～6.39% respectively.CONCLUSION:The method is simple,stable and highly sensitive and could meet with the research of clinical pharmacokinetics.

0.05) . AEP index increased sharply from 42 to 67 when the patients regained consciousness (OAA/S increased from 2 to 3) but BIS increased gradually from 64 to 72 indicating that AEP index had better discriminatory performance. OAA/S correlated fairly well with BIS , AEP index and target-controlled concentration of propofol and r was 0.781, 0.684 and - 0.580 respectively. Conclusions Both AEP index and BIS can predict fairly well the level of sedation but AEP index prooes to be better in distinguishing conscious from unconscious.

ve To compare the effects of coronary-artery-bypass (CAB) surgery with and without cardiopulmonary bypass(CPB) on hemodynamics and the function of the grafts. Methods Thirty-five patients undergoing elective CAB surgery were studied. CAB was performed either with hypothermic CPB (n = 15) or without CPB(off-pump, n = 20) . The patients were premedicated with intramuscular pethidine 50 mg and scopolamine O.3mg. Anesthesia was induced with intravenous midazolam 5-15mg, fentanyl 5-20?g?kg and pancuronium 0.1 mg?kg-1 or pipecuronium 0.1 mg?kg-1 and maintained with iv infusion of fentanyl 6-10?g?kg-1, propofol 2-4mg?kg-1?h-1 and intermittent boluses of pancuronium, midazolam supplemented with 1%-1.5% isoflurane inhalation. In off-pump group naso-pharyngeal T?was maintained at 37.2℃ during operation. The amount of heparin used was equal to about one-third of amount used during CPB and ACT was maintained above 250 seconds. MAP was maintained at 70-90 mm Hg. While blood vessel was being grafted onto the coronary arteries heart rate was maintained at 60-80 bpm, otherwise esmolol 10-20mg was given iv every 5 min until it was satisfactorily controlled. In CPB group, during CPB naso-pharyngeal T?was maintained at 32℃-34℃, MAP at 50-70 mm Hg and blood gases and electrolytes within normal range. Right radial artery was cannulated and 7.5F Swan-Ganz catheter was inserted via internal jugular vein into pulmonary artery for hemodynamic monitoring and blood gas analysis. ECG, SpO2 were continuously monitored during operation. At the end of operation in patients with internal mammary artery used as graft, the flow rate of grafts was measured with 3mm Doppler probe.Results (1) After CAB cardiac index (CT) increased significantly in off-pump group(P0.05) . (3) There was no significant difference in the blood flow of artery graft and myocardial oxygen delivery (MDO2), and consumption ( MVO2) as well as MDO2/MVO2 between the two groups. Conclusions Off-pump CAB surgery has less effects on hemodynamics but systemic and myocardial oxygen delivery and consumption are similar between the two groups.

0. 5mv. LAD occlusion was maintained for 50min and then released for reperfusion (120min) . Myocardial infarct size was measured by nitroblue tetrazolam at the end of experiment. Results There was no statistically significant difference in HR, MAP, cardiac output (CO), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure ( LVEDP) and rate-pressure products ( RPP) among all groups during ischemia and early reperfusion period except for LVEDP in control group which was much higher than that in all preconditioning groups during the late reperfusion period. Compared with the control group, desflurane, sevoflurane, isoflurane and G+ desflurane reduced myocardial infarct size by 41%, 47%,31.7% and 17.8% respectively without significant homodynamic effects. Myocardial infarct size in G + desflurane groups was significantly larger than that in desflurane group. Conclusion Preconditioning with desflurane, sevoflurane and isoflurane reduce myocardial infarct size in rabbits to some extent. The protective effects may be partly medialed via activation of KATP channel.

Objective The study was designed to compare the effects of desflurane and isoflurane on the vecuronium-induced neuromuscular block in the elderly patients. Methods Thirty ASA class I - II elderly patients aged over 70 yr undergoing elective surgery under general anesthesia were randomly divided into 3 groups: desflurane group ( I , n = 10) ; isoflurane group ( II , n = 10) and 3 control group ( III , n = 10). Anesthesia was induced with midazolam 0.02-0.05 mg? kg-1 , propofol 0.5-2.0 mg ? kg-1 and fentanyl 2-5?g? kg-1 maintained with inhalation of 6% desflurane(1 MAC) +50% N2O in oxygen (group I ) or 1.15% isoflurane + 50% N2O in oxygen(group II ) or 50% N2O in oxygen (group III ) supplemented with intermittent iv boluses of propofol and fentanyl when necessary. Neuromuscular block was monitored using accelograph (TOF GUARD , Denmark) .A total dose of vecuronium 40 mg ?kg-1 was divided with 4 equal doses of 10?g ? kg-1 , which was administered accumulatively in each patient. The next dose was given when the effect of the previous dose had reached its peak (T1 was no longer depressed in the height of 3 successive stimuli) .The cumulative dose-response curves of the 3 groups were established. The onset time and maximum depression of T1 of the initial dose and 3 incremental doses were recorded. After the last increment of 10 ?g?kg-1, the time for T1 to returned to 25% ,75% ,90% and TOF ratio(T4/T1) to 70% were recorded. The recovery index was also calculated.Results The demographic data were comparable between the 3 groups. The ED50 and ED95 were significantly lower in desflurane and isoflurane groups than those in control group(P 0.05 ) . The time for T1 to return to 25 % , 75 % and 90 % was significantly longer in desflurane and isoflurane group than that in the control group. The recovery from vecuronium-induced neuromuscular block was slower in desflurane group than that in isoflurane group( P

Objective To investigate the effect of desflurane pretreatment on the density of muscarinic (M)-receptors on anoxic/reoxygenated rat cardiac myocytes. Methods Myocytes were obtained from ventricle of 2-3 day SD rats and incubated for 3 days. Then they were randomly allocated to one of 5 groups: group I received no treatment and served as control ( n = 5); group Ⅱ underwent 2 h hypoxia (liquid culture medium was insufflated with a gas mixture of 1 % CO2 , 1 % O2 and 98% N2) followed by 1h reoxygenation ( n = 6) ; group Ⅲ was pre-treated with 1.5 MAC desflurane (9% ) for 20 min, followed by 10 min washout before the same duration of hypoxia/reoxygenation as in group II ( n = 6) ; group IV underwent longer duration of hypoxia (48 h) followed by 24 reoxygenation ( n = 5) ; group V was pre-treated with 1.5 MAC desflurane (9% ) for 20 min followed by 10 min washout, then underwent longer duration of hypoxia/reoxygenation as in group IV ( n = 5) . The density of M-receptors was measured by the radio-ligand binding assay (RLBA) .Results The density of M-receptors was significantly lower in group Ⅱthan that in group I ( P

Objective To investigate the relationship between cerebral 0, metabolism during coronary artery bypass graft (CABG) performed with cardiopulmonary bypass (CPB) and postoperative mental disorders (POMD) in the elderly.Methods Thirty patients (13 male,17 female) aged 65-76 yr undergoing CABG performed with CPB were studied. Patients with senile dementia were excluded. The patients were premedicated with scopolamine 0.3 mg and pethidine 50mg. Anesthesia was induced with midazolam 0.05-0.1 mg?kg_(-1), propofol 0.2-0.5 mg?g_(-1), fentanyl 10-15?g?g_(-1) and vecuronium 0.1-0.3 mg?g_(-1) and maintained with isoflurane inhalation and intermittent iv boluses of fentanyl. Nasopharyngeal temperature (T) was maintained at 26℃-28℃) during CPB. Radial artery was cannulated for BP monitoring and blood sampling.Swan-Ganz was placed via right internal jugular vein (UV).Another catheter was inserted into right UV and threaded retrogradely until J point for blood sampling. Blood samples were taken from artery and UV simultaneously for blood gas analyses and determination of blood glucose and lactate concentration before anesthesia (T_1 ),immediately after induction of anesthesia (T_2), during splitting of sternum (T_3) when T was reduced to 28℃ (T_4) and rewarmed to 35℃(T_5 ) and at the end of bypass (T_6 ).Cerebral O2 delivery (CDO2 ),cerebral oxygen consumption (CMRO2),cerebral glucose consumption (CMRglu) and lactic acid production (ADVL) were calculated. POMD was assessed using CAM-ICU chart.Results (1)Seven patients developed POMD (7/30 or 23.3% ).(2) Low jugular bulb 02 saturation (SjO2 ≤50% or PjO2≤25% mm Hg) was observed in 8 patients during rewarming. The incidence was significantly higher in POMD patients (3/7 or 42.96%) than that in non-POMD patients (5/23 or 21.74%). (3) CBF/CMRO2 was significantly lower in POMD patients than in non-POMD patients during rewarming.(4) CMRO2/CMRglu was significantly lower but ADVL was significantly higher in POMD patients than in non-POMD patients during hypothermia, rewarming and at the end of CPB.(P