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Objective To evaluate the effect of age factor on the analgesic efficacy of morphine during recovery from remifentanil-based anesthesia in pediatric patients undergoing minor surgery.Methods Fifty pediatric patients of both sexes,aged 3-10 yr,with body mass index ≤ 30 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective tonsillectomy,were divided into preschool group (3-5 yr,n=30) and school-age group (6-10 yr,n =20) according to age.Anesthesia was induced by inhaling 8％ sevoflurane and Ⅳ morphine 0.1 mg/kg.Pediatric patients were mechanically ventilated after tracheal intubation,and end-tidal pressure of carbon dioxide was maintained between 35-45 mmHg.Anesthesia was maintained by inhalation of 2％-3％ sevoflurane and Ⅳ infusion of remifentanil 0.2 μg · kg-1 · man-1.Pain was evaluated using Faces Pain Scale (FPS) and Face Legs Activity Cry Consolability (FLACC) scale during the recovery period in the postanesthesia care unit.When FPS or FLACC scores ≥ 4.morphine 0.05 mg/kg was intravenously injected.When pain was still unrelieved after morphine was given for 2 times (time interval 5 min),fentanyl 1 μg/kg was intravenously injected until FPS and FLACC scores ＜4.The requirement for analgesics and consumption of analgesics (fentanyl consunption was converted into morphine consumption) were recorded.The development of nausea and vomiting,pruritus and respiratory depression was also recorded.Results Compared with preschool group,the requirement for analgesics and consunption of analgesics were significantly decreased during recovery from anesthesia (P＜0.05),and no significant change was found in the incidence of nausea and vomiting in school-age group (P＞0.05).No pruritus or respiratory depression was found in two groups.Conclusion The analgesic efficacy of morphine is affected by age factors during recovery from remifentanil-based anesthesia in pediatric patients undergoing minor surgery,and morphine produces better analgesic efficacy in school-age pediatric patients than in preschool pediatric patients.
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Objective · To evaluate the value of ultrasonic measurement of distance from skin to epiglottis (DSE) for predicting the difficult airway. Methods · 71 patients (20-80 year-old, ASA Ⅰ-Ⅲ ) undergoing endotracheal intubation and general anesthesia for an elective surgical procedure were enrolled. Conventional airway evaluation was performed. The distance from skin at thyroid cartilage upper edge to epiglottis was measured using ultrasound before anesthesia and compared between patients with difficult airway and normal airway. The effects of different methods for evaluating difficult airway were analyzed Results · The ultrasonic measurements of DSE on parasagittal view in patients with difficult airway and normal airway were (23.31±0.43) mm and (19.21±0.27) mm, respectively. The difference was statistically significant (P=0.003). The area under the ROC curve of ultrasonic measurement was 0.799 (95% CI:0.639-0.958) with the best cutoff point of 23.6 mm. The specificity of ultrasonic measurement was significantly increased as compared with Mallampati classification (96.43% vs 71.40%, P=0.004). The difference in sensitivity was not statistically significant (60.00% vs 73.33%, P=0.170). Conclusion · Ultrasonic measurement of DSE on parasagittal view can be used to predict the difficult airway.
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Objective To compare the neuromuscular blocking effects of rocuronium given by intermittent bolus injection, continuous infusion and target-controlled infusion during liver transplantation. Methods Thirty-six patients with hepatic failure of both sexes aged 21-63 yr weighing 48-80 kg undergoing liver transplantation were studied. The donor livers were obtained from living donors. The patients were divided into 3 groups according to the mode of rocuronium administration ( n = 12 each): group Ⅰ intermittent bolus injection (group Ⅳ); group Ⅱ continuous infusion (group CI) and group Ⅲ target-controlled infusion (group TCI). Neuromuscular block was assessed by TOF stimulation of ulnar nerve (TOF-Watch SX). Anesthesia was induced with midazolam 5 mg,fentanyl 4-6 μg/kg and propofol 1.0-1.5 mg/kg, and rocuronium was administered using different modes of administration. A bolus of rocuronium 0.6 mg/kg was given during induction and supplemental rocuronium 0.15 mg/kg was given when T1 was returned to 25% in preanhepatic stage and T4/T1 (TOFR) returned to 25% in anhepatic and neohepatic stages in group Ⅳ. TCI at an initial target effect-site concentration of 3 μg/ml was started during induction, the concentration was adjusted to maintain T1 at 5%-10% , TCI was temporarily suspended at the beginning of anhepatic and neohepatic stages, and then TCI at a target effect-site concentration of 0.1 μg/ml was started again and the concentration was adjusted to maintain T1 at 5%-10% in group TCI. A bolus of rocuronium 0.6 mg/kg was given during induction, the initial infusion rate was set at 30 μg· kg-1 ·min-1 and then adjusted to maintain T1 at 5%-10% in preanhepatic stage, CI was temporarily suspended at the beginning of anhepatic and neohepatic stages, and then it was started again at 1 μg· kg-1 · min-1 in preanhepatic stage and the infusion rate was adjusted to maintain T1 at 5%-10% in group CI. Tracheal intubation was performed when the maximal effect was achieved. The administration was stopped after suture of the peritoneum. The onset time, the maximal depression of T1 , intubation condition, recovery time and the total amount of rocuronium consumed were recorded.Results There was no significant difference in onset time, the maximal depression of T1, intubation condition,ecovery time and the total amount of rocuronium consumed among the 3 groups ( P ＞ 0.05). Conclusion There is no significant difference in the onset and recovery when neuromuscular blocade was induced by rocuronium via Ⅳ, CI and TCI, but neuromuscular blockade induced by rocuronium via TCI and CI is more stable than that induced by rocuronium via Ⅳ during liver transplantation.
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Objective To investigate the incidence of postoperative intubation-related complications and the need for measurement and adjustment of cuff-pressure of endotracheal tube. Methods Five hundred and nine patients of either sex undergoing elective surgery under general anesthesia with tracheal intubation were divided into 2 groups: control group (group C)and cuff-pressure measured group (group CPM). Operation time and duration of endotracheal tube were recorded. Twenty patients with the duration of endotracheal tube 120-180 min in each group were selected. Their tracheal mucous membrane was examined by fiberoptic bronchoscopy at the time of withdrawal of endotracheal tube. Postoperative complications including cough and bloody sputum were also recorded at 24 h after extubation. Results The two groups were comparable with respect to age, sex, operation time and the duration of endotracheal tube. The incidence of sore throat and bloody sputum was significantly higher in group C than in CPM group. The incidence of sore throat and bloody sputum was significantly increased as the duration of endotracheal tube was prolonged in control group while in CPM group only the incidence of sore throat was increased. Varying degrees of injuries to tracheal mucous membrane were observed with fiberoptic bronchoscope.The injuries were more serious in group C than in CPM group. Conclusion Measurement of intracuff pressure is helpful for reducing the tracheal intubation-related complications.
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Objective To compare different dose of remifentanil combined with propofol for painless abortion and approach to an appropriate dose of remifentanil.Methods Ninety pregnant women with ASA 1 were randomly divided into three groups(n=30)before administrating remifetanil,a bolus midazolam 1 mg was injected inminutes later.These two drugs did not stop administration until three minutes before the end of negative suction.MAP,HR,SpO2,BIS,RR,VT,PET CO2 were monitored.The onset,operation and recovery time,sedation score and adverse reaction were recorded.Results Sedation scores were significantly different between group A and C [(3.90±0.97)and(4.90±0.85),t=4.24,P＜0.01].Three cases in group A were found moving.MAP,HR,BIS decreased as compared witll baseline.HR reduced significantly in group C(P＜0.05,P＜0.01).Respiratory movement was lower and shallower.RR,VT decreased compared to preoperative one.PET C02 increased gradually (P＜0.05,P＜0.01).There were two cases of respiratory depressing in group A,four cases in group B and ten cases in group C(five cases apnea more than three minutes).All patients used oxygen mask to maintain SpO2＞95%.Incidence of adverse reactions such as chest titanic,nausea and vomiting,itching were of no difference among three groups(P＞0.05).All patients were satisfied with anesthesia.Conclusion The appropriate infusing dose of remifetory devices such as oxygen mask and monitoring life signs are very important to prevent respiratory depress and bradycardia during operation.
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OBJECTIVE:To build up a method for the determination of propofol in plasma by RP-HPLC with fluores?cence detection.METHODS:The separation was performed on a reversed-phase Zorbax Eclipse XDB-C 18 column(150mm?4.6mm,5?m)with a mobile phase consisting of methanol-acetonitrile-0.005mol/L sodium acetate buffer(pH4.0)(55∶20∶25,V/V).Propofol was extracted from plasma and dissolved in the mobile phase then detected at276/310nm.RESULTS:The calibration curve had the fine linearity in the concentration range of0.015625～8?g/ml(r=0.9998).The limit of detection(LOD)was1ng/ml(S/N ratio=3),the limit of quantification(LOQ)was10ng/ml.The absolute recovery was89.33%～93.37%,the relative recovery was97.75%～103.31%.The within-day and between-day precision(RSD%)was1.38%～5.02%and4.45%～9.056%respectively.CONCLUSION:The method is simple,stable and highly sensitive and can meet with the research of clinical pharmacokinetics.
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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.
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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
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Objective: To observe the effects of neuromuscular blockade after combining atracurium (ATC) with veeuronium (VEC). Method: Fifty-four patients undergoing elective abdominal surgery(ASA grade Ⅰ-Ⅱ) were allocated randomly into 3 groups. After induction with intravenous midazolam-etomidate-fentanyl, neuromuscular blockade was measured with the train of four (TOF) to the ulnar nerve by monitoring the contraction of musculus adductor pollicis. The onset time and the peak effect were observed. According to the dose-effect relationships of the combination of ATC and VEC and that of either ATC or VEC given alone,the ED_(50) and ED_(95) were caeulated. The isogram and algebraic methods were used to analyse interaction between them. Result: The fraction ED_(50) values of ATC and VEC in combination were 52.26 and 11.71?g/kg respectively, The algebraic subtotal of combinations was 0.75
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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
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To assess the concentration-responses relationships of propofol, 16 adult patient,ASA grade Ⅰ-Ⅱ,scheduled for upper abdominal operation, were randomly allocated to undergoing epidural block (group Ⅰ, n = 8)or combined anesthesia (group Ⅱ, n = 8) respectively. After a bolus injection of propofol 2.5mg ?kg, blood pressure (BP), heart rate (HR) and tidal volume (TV) were recorded, and drowsiness,amnesia,cooperation and orientation were evaluated by scorring scales in both groups. The venous samples were taken before and after the administration to measure the propofol plasma concentration by spectrofluorophotometric detector. The results revealed that there were no significant differences in pharmacokinetic parameters between two groups;the plasma concentration of propofol at 2. 5rag. L~(-1) was required for adequate anesthesia,and 1.5 to 1.9rag. L~(-1) for hypnosis,the patients were fully awake at 0.94?0.3mg. L~(-1); BP,HR and TV were significantly depressed at more than 2.0rag. L~(-1), and recovered to baseline at less than 1.5mg. L~(-1). It is suggested that there are good relationships between propofol plasma concentrations and its pharmacodynamic responses.
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Objective To examine the changes in respiratory mechanics and efficacy of mechanical ventilation during perioperative period in patients undergoing valve replacement and determine the possible causes Methods Twenty ASA Ⅱ Ⅵ patients (8 male, 12 female), aged 24 65 years , undergoing valve replacement were studied The patients were premedicated with intramuscular phenobarbital 0.1g, pethidine 50mg and scopolamine 0 3mg Anesthesia was induced with midazolam, fentanyl and vecuronium and maintained with inhalation of low concentration of desflurane and intermittent intravenous boluses of fentanyl, midazolam and vecuronium Valve replacement was performed with moderate hypothermic cardiopulmonary bypass (CPB), The patients were mechanically ventilated with pure oxygen Tidal volume was maintained at 8 10ml/kg, frequency 12 15 bpm and I∶E ratio 1∶1 5 2 During CPB airway pressure was maintained below 5 cmH 2O After operation the patients were transferred to ICU and mechanically ventilated using Siemens 900C ECG, SpO 2, BP, CVP, left auricle pressure and urine output were routinely monitored Respiratory mechanics was measured with Novametrix 8100 multifunction respiratory monitor Mean airway pressure, peak airway pressure, airway resistance, chest lung compliance and respiratory work were measured 20 min after induction of anesthesia, 10 min before CPB, 10 min after termination of CPB, at the end of operation and 2, 6 and 18h after operation Results Work of breathing and airway resistance increased gradually after induction and reached the maximum at 6h after operation Dynamic compliance decreased significantly before CPB but increased slightly after CPB, then decreased again and to the minimum at 6h after operation Mean airway pressure and peak inspiratory pressure went up significantly after operation All parameters mentioned above returned to the preoperative levels before the patients were weaned from respiratory support in ICU Couclusions Thoracotomy and CPB are the main causes of changes in respiratory mechanics in patients undergoing valve replacement The effects reached the peak at 6 h after operation Therefore mechanical respiratory support is essential for the patients until respiratory function recovers and should be maintained for more than 6h after operation
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0 05), while the difference between RBco and TDco was significant before CPB was started and 60min after termination of CPB (P
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Objective To investigate the relationship among the depth of midazolam induced sedation, the plasma midazolam concentration and quantified electroencephalogram(EEG) and determine the appropriate depth of sedation during regional anesthesia Methods Twenty adult ASA I II patients(male 7,female 13)scheduled for thyroid adenoma or cyst operation under cervical plexus blockade were studied The age ranged from 19 57 years [mean (46 4?9 5)yr] and weight from 40 83kg[mean (63 1?10 3)kg] Patients with liver or kidney disorders or habitually taking benzodiazepine were excluded The patients were premedicated with phenobarbital sodium 0 1g Dorsalis pedis artery was cannulated for blood sampling Besides blood pressure, heart rate and SpO 2, quantified EEG (BIS and 95%SEF) were continuously monitored and recorded Level of sedation was assessed using the modified observer's assessment of alertness/sedation (OAA/S) scale The BIS, 95%SEF and plasma midazolam concentration (Cm)were correlated with the OAA/S scores using nonparametric Spearman's rank correlation analysis Results As depth of sedation deepened from an OAA/S score of 4 to 1, BIS value decreased from 91 5?2 6 to 63 1?5 7, 95%SEF from 21 4?2 0 to 15 2?2 9 and plasma midazolam concentration increased from (120 8?55 2)ng/ml to (533 0?139 4)ng/ml BIS, 95%SEF and Cm were all well correlated with the OAA/S score The coefficients of correlation between BIS, 95%SEF, Cm and OAA/S score were 0 952,0 674 and -0 856 respectively Conclusions Cm, BIS and 95% SEF are all well correlated with the depth of midazolam induced sedation and can all be used to monitor the depth of midazolam induced sedation, but BIS is the best among them BIS value 75 82 and OAA/S score 2 3 are the most appropriate level of sedation during regional anesthesia
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Objective To investigate the effects of regional myocardial stunning on systemic hemodynamics and myocardial oxygen balance Methods Thirty three open chest anesthetized dogs were subjected to 15min left anterior descending (LAD) coronary artery occlusion under normal temperature, the systemic hemodynamics, coronary blood flow (CBF), myocardial oxygen delivery(MDO 2) and consumption(MVO 2)were determined following reperfusion Results MAP decreased slightly during LAD occlusion, but returned to baseline following reperfusion CO, SV and LVSWI reduced rapidly after LAD occlusion, increased slightly 5min following reperfusion, followed by a more severe reduction , with the progressive increases of SVR and PVR during whole periods At the early stage of reperfusion (5min), CBF, MDO 2 and MVO 2 increased significantly, then decreased rapidly 10min following reperfusion Myocardial oxygen extraction rate remained stable during whole procedures Histological changes of ischemic area 30min following reperfusion showed interstitial and intracellular edema, mitochondrial vacuolization, and capillary stasis under electronic microscopy Conclusions Regional myocardial stunning may resulte in sinificant changes of systemic hemodynamics; at the early stage of reperfusion, oxygen consumption paradox occurres ,but MDO 2 matches MVO 2 10min following myocardial reperfusion
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desflurane. The one of hepatotoxic mechanism of inhatational anesthetics may be to inhibit the proliferation and albumin secretion.
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Gelofusine is a plasma substitute made from modified fluid gelatin,it's hemodynamic and biochemical effects on organism were studied in 6 anesthetized dogs and 20 patients scheduled for undergoing open heart surgery(OHS). Different degree of isovolemic acute hemodilution was achieved by supplying the gelofusion at the same amount of blood withdrawn. The results showed,in patients group, after hemodilution, no significant changs were observed in HR, MAP, DO_2 and CaO_2, wherease, CO, CI, and VO_2 increased. In dog group, HR and MAP remained, CaO_2 and SVRI decreased, CO, CI, DO_2 and VO_2 increased at the degree of isovolemic hemodilution less than 20 ml/kg, DO_2 began to decrease at the degree of hemodilution greater than 20ml/kg. In both groups, there's no significant changes in the concentration of K~+, Na~+ ,CI~- and pH value after hemodilution. Our findings supports previous observation about gelofusion's effect to maintain the blood volume and reserve the hemostasis,in addition,it has no deterious effect on coagulation
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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.
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0.05). The onset time of 0.2mg/kg and 0.4mg/kg cisatracurium was significantly shorter than that of 0.1mg/kg cisatracurium and 0.5mg/kg atracurium (P
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Objective To observe the effects of desflurane, sevoflurane and isoflurane on hepatic oxygen balance and hepatic blood flow Methods Fifteen pigs were randomly divided into three groups: A desflurane group(n=5), B sevoflurane group(n=5), C isoflurane group(n=5) This study observed the effects of desflurane, sevoflurane and isoflurane on systemic and hepatic blood flow and oxygen balance with different concentrations using continuous thermodilution cardiac output monitor and ultrasonic Doppler blood flow monitorResults ①Hepatic blood flow: total hepatic blood flow(THBF) decreased dose-dependently in three groups without significant differences between groups The effects of desflurnae and sevoflurane on THBF were same as those on cardiac output(CO), while the effect of sevoflurane on THBF was larger than that on CO ②Oxygen balance: both systemic oxygen delivery(DO_2) and hepatic oxygen delivery(HDO_2) decreased significantly with the increasing of inhalation concentrations, systemic oxygen delivery(VO_2) and hepatic oxygen consumption(HVO_2) decreased significantly only at high concentration The effects of desflurnae and sevoflurane on HVO_2 and HDO_2 were same as those on VO_2 and DO_2, while the effect of sevoflurane on HDO_2 was larger than that on DO_2, but the effect of sevoflurane on HVO_2 was still same as that on VO_2Conclusions Because of the dose-dependently decreased hepatic blood flow, hepatic oxygen delivery decreases significantly, but hepatic oxygen consumption can be maintained well by self-regulation of hepatic oxygen extraction ratio,indicating that there is almost no influence on hepatic intracellular respiration and metabolism