The neuromuscular and cardiovascular effects and endotracheal intubating conditions of bolus intravenous rocuronium 0.6mg/kg or 0.75mg/kg in 20 patients under balanced anesthesia,were studied, Intubating conditions were evaluated as excellent or good in all patients,except for one with poor intubating conditions following 0.6mg/kg. Onset times of both groups were 73.1 s and 67.1 s;neuromuscular blockade durations 24.9min and 32.0min; 25% recovery times 37.3min and 45.4min; 75% recovery times 46.4min and 58.7min;recovery index 9.1min and 13.3min,respectively. The cardiovascular effects after rocuronium in both groups were minimal.

Objective: To analyse correlation of bispectral index,spectral edge frequency of electroencephalogram with midazolam-induced sedation. Method: 30ASA grade Ⅰ-Ⅱ adult patients, undergoing elective surgery under regional anesthesia were randomly devided into three groups according to intravenous bolus doses of midazolam,i, e. group Ⅰ:0.05mg?kg~(-1),group Ⅱ:0.1mg?kg~(-1),group Ⅲ:0.2mg?kg~(-1). After an intravenous bolus dose of mida zolam was administered,both bispectral index (BIS), 95% spectral edge freguency (SEF) of electroencephalogram were monitored and their correlation with midazolam induced sedation was analysed. Result: Both BIS and 95% SEF-correlated with midazolam-induced sedation significantly (r= 0.86,0.73, P

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 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 The effect of lidocaine and bupivacaine on the Na+ current of dorsal horn neurons was observed to further evaluate the mechanism of local anesthetics . Methods The dorsal horn neurons of the SD neonates(0-7 d) were isolated acutely. Under the condition of holding voltage -80mV , and testing voltage -30mV with duration of 20 ms , the whole-cell patch-clamp technique was applied to recording the changes of voltage-gated Na+ currents following the administration of lidocaine or bupivacaine at 50-1000?mol/L.Results The voltage-gated Na+ currents ranged from 0.5-8nA peak amplitude , was inhibited by lidocaine and bupivacaine at clinical concentrations, the inhibitory degree was parallelly correlated with the concentration of local anesthetics(r=0.949 and 0.847 ,P

Objective To study the effects of propofol on the whole-cell sodium currents in rat sympathetic neurons in order to investigate the mechanisms of propofol-mediated peripheral vasodilation.Methods Whole-cell patch-clamp recordings were made from enzymatically isolated rat superior cervical sympathetic neurons.Results Propofol dose-dependently blocked the whole-cell sodium currents evoked by a voltage step from a holding potential of -- 80mV to 0mV with a mean IC50 value of 32. 19?mol/L (r = 0. 982, P

Objective To study the effects of desflurane on Ca 2+-ATPase activity isolated rat cardiac myocyte plasma membrane ,for the mechanisms of its inhibitory myocardial function.Methods The effects of different concentration desflurane(0%-11%) on Ca 2+-ATPase activity were studied at different calcium concentration(04-20?mol/L) and at 25℃ or 37℃Results Ca 2+-ATPase activity wan depressed by desflurane,the greater inhibitory effect,the higher desflurane concentration,and more severely at low calcium concentration or at 37℃ than at high calcium concentration or at 25℃Conclusions At clinical concentration desflurane produces tha inhibitory effect on rat cardiac myocyte plasma membrane Ca 2+-ATPase activity dose-dependently,which may in part explain its depression on myocardial function.

Objective To investigate the effects of ropivacaine on the whole cell sodium currents in rat sympathetic ganglion neurons in order to determine whether sympathetic ganglion is involved in the ropivacaine cardiotoxity. Methods The sympathetic neurons were enzymatically isolated from the superior cervical ganglion. The effects of ropivacaine on the whole cell sodium channel currents were assessed using patch clamp technique. Results Ropivacaine blocked the whole cell sodium channel currents dose dependently. When the holding potential (Vh) was -80mV and Vt Omv , 0.01?mol/L ropivacaine reduced peak currents by 30.02% with a mean IC50 of 2.68?mol/L. The blockade was also potential dependent. When Vh was -60mv, the mean IC50 was 1.55?mol/l. 1.0?mol/L ropivacaine reduced the peak value of I V curve by 30.66% but did not affect the shape of I V curve and caused 2.56mv shift of voltage dependence activation curve to depolarized potentials and 3.56mv shift of steady state inactivation curve to more hyperdepolarized potentials.The conditioning pulse potential at which half maximal channels were activated (V1/2), changed from -52.99mv to -56.44mv and the test potential at which half maximal channels were activated (V1/2), changed from -25.2mv to -22.64mv. Conclusions Subconvulsive concentration of ropivacaine significantly inhibits sympathetic ganglion neurons in a dose dependent and potential dependent way through the inactivation of sodium channel,indicating that sympathetic ganglion neurons may contribute to the cardiotoxity of ropivacaine.

Objective To investigate the effects of droperidol on the Na+ currents in rat dorsal root ganglion neurons.Methods The rat dorsal root ganglion neurons were enzymatically dissociated. Whole-cell patch-clamp technique was applied to record Na+ current. Results 3-300?mol?L-1 Droperidol inhibited the sodium currents by 14.12%-78.46% (P0.05, n =7).Conclusions Droperidol inhibits Na+ currents in rat dorsal root ganglion neurons in a concentration- and voltage-dependent manner. The results suggest that the concentration of epidural droperidol clinically applied during epidural patient control analgesia may enhance the analgesic effects.

Objective To evaluate the feasibility of using auditory evoked potential index(AAI) to monitor the depth of nitrous oxide anesthesia. Methods Sixteen ASAⅠ-Ⅱpatients aged 23-64 years, weighing 51-86 kg scheduled for elective surgery under general anesthesia were studied. Patients with psychoneural diseases and hearing disturbances were excluded. The patients were premedicated with phenobarbital sodium 0.1g and atropine 0.5mg. AAI, BIS, 95% SEF, BP, HR, SpO2 monitoring were started before induction of anesthesia. The patients were preoxygenated for 5 min using a close-fitting face mask and 100% O2 at l0L?min-1 . Inhalation of nitrous oxide was then started. Nitrous oxide concentration was gradually increased in increments of 10% from 0% to 70% . AAI, BIS and 95%SEF were recorded and observer's assessment of alertness/sedation (OAA/S) scores were measured at each 10% increment of end-tidal nitrous oxide concentration which was maintained for 5 min. The correlation between AAI, BIS, 95% SEF and OAA/S scores was analyzed. Results OAA/S scores and AAI decreased as the nitrous oxide concentration increased. AAI correlated closely with OAA/S scores and end-tidal nitrous oxide concentration (the coefficients of Spearman' s rank correlation ? = - 0.739, 0.837, P