Objective To evaluate the efficacy of bispectral index (BIS) in guiding sevoflurane anesthesia in children. Methods Forty-eight ASA Ⅰ or Ⅱ pediatric patients aged 1-12 yr undergoing elective urological surgery were randomized into 2 groups ( n = 24 each) : group Ⅰ control and group Ⅱ BITS. Each group was further divided into 3 subgroups according to the age (n = 8 each) : subgroup A ( 1 yr≤age < 3 yr) ,subgroup B (3 yr≤ age<6 yr ) and subgroup C (6 yr≤age ≤ 12 yr). The patients were premedicated with IM atropine 0.015-0.02 mg/kg. Anesthesia was induced with 5% sevoflurane and 60% N2O in O2. Tracheal intubation was facilitated with vecuronium 0.1 mg/kg. Anesthesia was maintained with inhalation of sevoflurane and,50% N2O in O2 and intermittent Ⅳ bolnses of vecuronium and fentanyl. In BIS group, BIS was maintained at 40-60 during operation and at 60-75 during the 15 min before the end of surgery. BIS was monitored and recorded but not available to the anesthesiologist in control group and the depth of anesthesia was maintained based on hemodynamic changes and clinical signs. MAP, HR, end-tidal sevoflurane concentration, BIS, emergence time, extubation time and PACU discharge time were recorded. The amount of sevoflurane consumed was calculated. Results There was no significant difference in the demographic data between the cotresponding age groups of BIS and control group. The BIS were maintained at 40-60 in control group. The BIS was significantly higher in BIS group than in control group except the subgroup A. The end-tidal sevoflurane concentration was significantly lower, and the emergence time, extubation time and PACU discharge time were significantly shorter in BIS group than in control group. There was no significant difference in MAP and HR between the 2 groups. Conclusion BIS monitoring can reduce sevoflurane consumption and allow faster emergence from sevoflurane anesthesia in children over 1 yr of age.

Objective: To examine the effects of midazolam-induced sedation on heart rate variability (HRV). Method:Fifteen ASA Ⅰ- Ⅱ adult patients,undergoing elective surgery under lumbar epidural anesthesia were randomly selected. An intravenous bolus dose of midazolam(1.5mg) was administered every 3-5 minutes until patients' sedation levels assessed by observers assessment of alertness sedation(OAA/S) scale had scores of 1. Spectral analysis of HRV was performed at different OAA/S scores and at 3min,5min and 10min following OAA/S score of 1. Result:All frequency components of HRV were significantly reduced as patients' OAA/S scores decreased,especially low frequency (LF) and total power. Midazolam decreased normalized unit power of LF from 33.5%?8.9% to 16.65?9.6% and increased normalized unit power of high frequency(HF) from 11.7%?4.2% to 20.5%?26.5%. LF/HF ratio also reduced. Conclusion:Midazolam shiftes the balance of autonomic nervous activity toward the parasympathotonic.

Objective To evaluate the effects of dantrolene pretreatment on diaphragmatic function in septic rats .Methods Thirty adult male Sprague-Dawley rats , weighing 200-220 g , aged 9-10 weeks , were randomized into 3 groups (n=10 each) using a random number table :sham operation group (group S) ,spesis group (group CLP) and dantrolene group (group D) .The animals were anesthetized with pentobarbital sodium . Dantrolene 6 mg/kg was injected intraperitoneally (in dimethyl sulfoxide 500 μl ) .Sepsis was induced by cecal ligation and puncture 1 h later in CLP and D groups .The left and right diaphragm was rapidly excised at 24 h after cecal ligation and puncture . The left diaphragm was used to detect the systolic function including the single stimulation twitch , dmax/dt , dmin/dt , maximal force of tetanic contraction , force-frequency curves , and fatigue index .Results Compared with group S ,the single twitch myopalmus ,dmax/dt ,dmin/dt ,maximum peak tension and fatigue index were significantly decreased in group CLP ,the single stimulation twitch ,dmax/dt ,dmin/dt and maximal force of tetanic contraction were decreased , fatigue index was increased in group D , and the force-frequency curve was shifted downward in CLP and D groups ( P<0.05 or 0.01) .Compared with group CLP ,the single stimulation twitch ,dmax/dt ,dmin/dt ,maximal force of tetanic contraction and fatigue index were significantly increased in group D ( P< 0.05 or 0.01 ) .Conclusion Dantrolene pretreatment can improve diaphragmatic function in septic rats .

Objective To evaluate the effects of propofol and thiopontal on calcium and potassium channels in rat ventricular myocytes and to elucidate the underlying mechanisms of their inhibitory effect on myocardium. Methods Freshly isolated ventricular myocytes were prepared from hearts of rats by trypsin. The effects of propofol and thiopental on L-type calcium current(Ica) and delayed rectifier potassium current(IK)were compared using whole-cell patch clump technique. Results Propofol and thiopontal produced a concentration-dependent inhibition of Ica. Peak concentration of propofol(50 ?mol?L~(-1)) and thiopental(100 ?mol?L~(-1)) during induction of anesthesia decreased Ica by 28% and 46% and shifted the steady-state inactivation curve to more negative voltage, but had no effect on the steady-state activation curve. Propofol and thiopental also decreased IK in a concentration-dependent manner, but the effects of both anesthetics on IK were smaller compared with their effects on Ica. Conclusion The findings of this study suggest that the negative inotropic of propofol and thiopental are, at least in part, related to decrease in Ca~(2+) trans-sarcolemmal current by accelerating L-type calcium channel inactivation. Both anesthetics decrease delayed rectifier potassium current, thus partially antagonizing the effect of decreased calcium current.

Objective: To explore the effects of desflurane on systemic and hepatic hemodynamics and oxygen delivery to the liver. Method: 11 healthy mongrel dogs were anesthetized with 0.5 and 1.0 MAC desflurane respectively. The changes of systemic, pulmonary and hepatic hemodynamics,systemic oxgen delivery and consumption,oxygen delivery to the liver were measured continuously. Blood flow of hepatic artery and portal vein was monitored with electromagnetic flowmeter. Result: During inhalation of 0.5 MAC desflurane,HR.MAP.SVR,portal vein and total hepatic oxygen delivery decreased significantly(P

Objective To investigate the effects of propofol on the release of noradrenaline ( NE) from the locus coeruleus in the brain of rabbits trying to elucidate the central mechanism of the cardiovascular inhibition induced by propofol.Methods Nine healthy male New Zealand rabbits weighing 2.0-2.5 kg were used in this study. A trocar (0.8 mm in diameter) was inserted into locus coeruleus using the stereotactic technique and fixed. Four days later push-pull perfusion of the brain was performed. 37℃ artificial cerebrospinal fluid (aCSF) was infused through the trocar at 0.1 ml?min-1 . A loading dose of propofol 2 mg?kg-1 was given i.v. followed by continuous infusion at 150 ?g?kg-1?min-1 for 30 min. The experiment was concluded at 20 min after propofol infusion. The perfusate having passed through the locus coeruleus was collected before and every 10 min during and after infusion. The NE concentration of the perfusate was measured by high performance liquid chromatography. Results The NE concentration of the perfusate from locus coeruleus significantly decreased after the loading dose and during the infusion of propofol and reached its bottom level at 10 min after loading dose. The maximal decrease was 75.5% [from (15.9 ? 3.2) pg??l-1 to (3.9?0.5) pg ? ?l-1]. Conclusion Intravenous propofol decreases the NE concentration in locus coeruleus. The cardiovascular inhibition induced by propofol may partly be explained by this central mechanism.

Objective To examine the effects of propofol, midazolam and pyrrolidine dithiocarbamate (PDTC) on acute lung injury (ALI) induced by normothermic cardiopulmonary bypass (CPB) .Methods Twenty-six adult SD rats of both sexes weighing 350-450 g were randomly divided into 4 groups: group I midazolam (MZ, n = 7); group 11 MZ + PDTC ( n = 7); group III propofol (PROP, n = 7) and group IV sham operation ( n = 5). The animals were premedicated with intraperitoneal (i.p.) atropine 1 mg?kg-1 and anesthetized with i.p. midazolam 4 mg?kg-1 and fentanyl 150?g?kg-1 in group I , II and IV or with i.p. propofol 30mg?kg-1 and fentanyl 150 ?g?kg-1 in group III . CPB was performed at a flow rate of 100 ml?kg-1? min-1 for 60 min. In group II PDTC 100 mg?kg-1 was given i.p. 30 min before CPB. In sham operation group the animals were anesthetized, intubated and mechanically ventilated but underwent no CPB. Arterial blood samples were taken before initiation of CPB (T1 ) , at the end of CPB (T2) and 60 min after CPB (T3) for blood gas analysis and determination of the expression of CD11b on neutrophils by flow cytometry. Respiratory index (RI) was calculated at T1 and T3 . The animals were killed at 60 min after CPB and the lungs were removed for broncho-alveolar lavage. PMN count, protein and IL-8 concentration of broncho-alveolar lavage fluid (BALF) and lung MDA content were determined. The lung histology was also examined. Results RI was significantly increased at T3 as compared to T1 in group MZ ( P

Objective To investigate the inhibitory effects of fentanyl on GABAA receptors in hippocampal pyramidal neurons of rat.Methods Pyramidal neurons were acutely isolated from 3-10 day old SD rats of either sex by enzymatic-mechanic method. GABAA receptor mediated currents ( IGABA) were recorded using voltage clamped whole cell patch clamp technique in gap-free mode at the holding potential (VH) of - 50 mV. Current-voltage relationship of IGABA was obtained in ramp protocol ranging from + 30 mV to - 110 mV and lasting for 1 600 ms. Data were collected by using a system consisting of Axopatch 200B patch-clamp amplifier, Pentium Ⅲ computer and Digidata 1200 interface. All experiments were performed at room temperature (22-25℃). Five to twelve neurons were used for each fentanyl concentration. The effects of fentanyl from 1.0 ? 10-5 ?mol?L-1 to 10. 0 ?mol?L-1 were evaluated by the inhibition rate of the peak amplitude of IGABA, the desensitization time constant (?des) of IGABA and the reversal potential (Ecl- ) of IGABA. A ?-opioid receptor selective antagonist CTAP 1 ?mol?L-1 was applied and its effects on fentanyl were recorded. Results (1) GAB A 1-1 000 ?mol?L-1 induced inward currents (IGABA) dose-dependently with an EC50 of 23.73 ?mol?L-1.IGABA induced by GABA 30 ?mol?L-1 was blocked by bicuculline 1 ?mol?L-1. (2) Fentanyl depressed IGABA dose-dependently with EC50 of 0.011 ?mol?L-1 and shortened the rdes of IGABA.(3) The inhibitory effects of fentanyl on IGABA were antagonized by CTAP. (4) Fentanyl 0.01 ?mol?L-1 and CTAP did not influence the reversal potential of IGABA (Ecl- -3.0 mV) .Conclusion Fentanyl inhibits the function of GABAA receptors through ?-opioid receptors in hippocampal pyramidal neurons. Hippocampus may play a role in the neuroexcitatory effects of opioids.

Objective To compare the effects of three different crystalloid solutions on arterial blood lactate concentration and acid-base balance during orthotopic liver transplantation (OLT) without veno-venous bypass. Methods Ninety ASA Ⅱ-Ⅳ patients with end-stage liver disease of both sexes (78 males, 12 females) aged 16-67 yrs weighing 45-87 kg undergoing OLT were randomly allocated to one of 3 groups ( n = 30 each): group Ⅰ received normal saline (NS); group Ⅱ received lactated Ringer's solution (LR) and group Ⅲ acetated Ringer's solution (Plasma A, Baxter) (PA). The crystalloid was infused at a rate of 6-8 ml?kg-1?h-1. Colloid, albumin, RBC and whole blood were infused based on BP, CVP and Hb concentration. The arterial pH, BE and lactate concentration were measured before anesthesia (T0 baseline) , before cross-clamping of the portal vein (T1) at 30 min and the end of anhepatic phase (T2,T3) , 5 and 30 min after unclamping of the portal vein (T4,T5) and at the end of surgery (T6). Results There was no significant difference in the amount of crystalloid, colloid and blood products infused during operation among the 3 groups. Arterial pH decreased significantly at T1 (immediately before anhepatic phase) as compared to the baseline value at T0 and the low pH was maintained until the end of operation. BE was significantly decreased during anhepatic phase (at T2 and T3 ) . The blood lactate was increasing during operation and was 3 times that of baseline value at the end of operation. However there was no significant difference in arterial pH, BE and lactate concentration among the 3 groups.Conclusion In OLT without venovenous bypass, blood lactate increases progressively but the lactated Ringer's solution does not have any effect on the blood lactate concentration.

Objective To evaluate the effect of intrathecal IL-10 gene on neuropathic pain induced by chronic constriction injury (CCI) to the sciatic nerve. Methods Sixty female SD rats weighing 230-250 g were anesthetized with pentobarfaital. Right sciatic nerve was exposed at the midthigh level and 4 ligatures were placed on the sciatic nerve with 4.0 catgut at 1mm interval. Intrathecal catheter (PE-10 tubing) were inserted at L5,6 interspace and correct placement was confirmed by outflow of CSF. The animals were randomized into 5 groups ( n = 12): group Ⅰ sham operation; group Ⅱ CCI; group Ⅲ,Ⅳ and Ⅴ received intrathecal (IT) normal saline (NS) (Ⅲ) or pcDNA 3.1 (Ⅳ) or pcDNA 3.1-IL-10 (Ⅴ) 3 days after CCI when the animals developed thermal hyperalgesia. Threshold to noxious thermal stimuli was measured before CCI (baseline), before and 2, 4, 7, 10 and 14 days after IT injection. CSF was collected on 1, 3, 7 and 10 days after IT injection for determination of CSF IL-10 concentration. Six animals were killed on 3rd and 14th days after IT injection respectively in each group and the sciatic nerve, lumbar segment of spinal cord ( L3-6) and hippocampus were isolated and blood was collected for determination of IL-10 mRNA expression (by RT-PCR) (on 3rd day after IT) and TNF-? content (on 14th day after IT) .Results Paw removal latencies were significantly longer 2-14 days after IT injection in group Ⅴ(CCI + pcDNA 3.1-IL-10) than in group Ⅲ (CCI + NS) and Ⅳ (CCI + pcDNA 3.1). The IL-10 mRNA expression in sciatic nerve, lumbar segment of spinal cord and hippocampus was significantly higher 3 days after IT injection while their TNF-? contents were significantly lower 14 days after IT injection in group Ⅴ than in the other 4 groups. The CNS IL-10 concentration on day 1-7 after IT injection was significantly higher in group Ⅴ than in the other 4 groups. Conclusion Intrathecal IL-10 gene injection can ease pain induced by CCI of the sciatic nerve through inhibition of inflammatory response.