The method, established for analysis of paeoniflorin in blood plasma, appeared a good linear relationship(r=0.9998). Using meta-hydroxybenzoic acid as internal standard and calibration factor combined, the quantitation precision of method could be raised. The result of determination of calibration factor conformed with the chromatography prescriptions in "Pharmacopoeia of China" (edited in 1990). The average recovery reached up 97.13％. The minimum detection amount was 5.6ng. The coefficients of within-day and between-day variation were 0.39％ and 1.17％, respectively. This method is suitable for paeoniflorin analysis of in vivo sample . At present,the in vivo absorption of Baihegujintang Granules (containing Radix Paeoniae alba or Radix Paeoniae rubra) by rabbit is preliminarily investigated utilizing this method.

BACKGROUND:It has been clinically confirmed that inhalation of hyperoxic oxygen for 36-48 hours can causes irreversible hyperoxic lung injury.Whether inhaling oxygen less than 50％ can reduce the potential oxygen toxicity in lung injury? OBJECTIVE:To observe the changes of lung ultrastructures after pure xygen inhalation for 7 hours through endotracheal intubation in dogs. DESIGN:A randomized and controlled animal experiment. SETTING:Department of Anesthesiology,Affiliated Hospital of Medical College,Qingdao University.MATERIALS:Totally 20 healthy hybrid dogs (6 females and 14 males),weighing 15-16 kg,were provided by the Animal Experimental Center in the Affiliated Hospital of Medical College,Qingdao University.BIRD 8400STi respiratory machine (Bird,USA) and HP-M102A multi-functional monitor (HP,USA) were used.METHODS:The experiment was completed in the Experimental Animal Center in the Affiliated Hospital of Medical College,Qingdao University from July 1999 to January 2000.① Interventions:The dogs were randomly ventilated with either fraction of inspired oxygen (FiO2) of 1 (group 1,n =10) or FiO2 of 0.34 (group 2,n =10),there were 3 females and 7 males in each group.All the dogs were ventilated for 7 hours.② Evaluation:The mean arterial pressure and heart rate were monitored at 1,3,5 and 7 hours after endotracheal intubation.Anesthetic gas monitor (Ohmeda 5250 RGM) was used to observe the fractional inspired oxygen concentration,end-tidal partial pressure of carbon dioxide (PetCO2), respiratory frequency and peaks of respiratory organs.Changes of lung ultrastructures of right lower lung lobe were observed with electron microscopy after 7-hour mechanical ventilation.MAIN OUTCOME MEASURES:① Hemodynamic parameters; ② Changes of lung ultrastructures. RESULTS:All the 20 dogs were involved in the anlaysis of analysis.① Results of hemodynamic parameters:There was no significant difference between the two groups at each time point mean arterial pressure,PetCO2,peaks of respiratory organs and heart rate (P ＞ 0.05).② Changes of lung ultrastructures:The results of electron microscope showed that in group 1,there were swelling mitochondria was arranged in disorder,less matrix,and hyalomere appeared,thin double-deck membrane in 50％ samples; Interalveolar septum stroma was with edema in 60％ samples;Polymorphonuclear leukocyte gathered in vessel or emigrated out of vessel in 50％ samples; In group 2,double-deck membranes of mitochondria were integral,densely matrix showed micro-granule shape in 90％ samples; Pinocytosis in epithelial cells of type Ⅰ lung strengthened,being destroyed,and pinocytosis in endothelial cells strengthened in 10％ samples; Interalveolar septum stroma was with edema,no polymorphonuclear leukocyte gathered in vessel or emigrated out of vessel or corpuscule was empty in type Ⅱ alveolar epithelium in 20％ samples.CONCLUSION:More pathological ultramicroscopic changes are observed after 7-hour mechanical ventilation with pure oxygen,which reduces after mechanical ventilation with 34％ oxygen.Oxygen concentration should be decreased while long-time mechanical ventilation is executed so as to reduce potential lung injury with oxygen toxicity.

Objective To compare the effects of dexmedetomidine and fentanyl on the median effective concentration (EC50) of propofol required for inducing respiratory depression.Methods ASA physical status Ⅰ or Ⅱ patients,aged 30-50 yr,weighing 50-75 kg,with body mass index of 22-28 kg/m2,scheduled for elective gynecological surgery under general anesthesia,were randomly divided into 3 groups:control group (group C),dexmedetomidine group (group D) and fentanyl group (group F).Dexmedetomidine 0.5 μg/kg and fentanyl 1.5 μg/kg in 10ml of normal saline were infused over 10 min in D and F groups,respectively,while the equal volume of normal saline was given in group C.Lidocaine was injected intravenously followed by target-controlled infusion of propofol.In C,D and F groups,the initial target concentration of propofol was 2.5,2.1 and 1.1 μg/ml,respectively,and the ratio between the two successive concentration gradients was 1.1.It was defined as positive when patients developed respiration depression.EC50 and 95％ confidence interval of propofol inducing respiratory depression were calculated.BIS values and OAA/S scores were recorded after admission to operating room (T0),after infusion of dexmedetomidine,fentanyl or normal saline,at 5 and 10 min after the start of propofol target-controlled infusion and after the target effect-site and plasma concentrations were balanced.Results EC50 (95％ confidence interval) of propofol required for inducing respiratory depression was 2.72 (2.55-2.91),2.15 (2.05-2.27)and 1.17(1.08-1.25) μg/ml in C,D and F groups,respectively.Compared with group C,the EC50 was significantly decreased in D and F groups and the BIS values and OAA/S scores were increased in group F (P ＜ 0.05),and no significant changes were found in the BIS values and OAA/S scores in group D (P ＞ 0.05).The EC50 was significantly decreased and the BIS values and OAA/S scores was increased in group F as compared with group D (P ＜ 0.05).When the BIS values reached 65 or OAA/S scores was 3,the effect-site concentration was significantly lower in D and F groups than in group C (P ＜ 0.05).In C,D and F groups,the percentage of patients who developed upper airway obstruction caused by glossocoma was 100％,60％ and 20％,respectively,and who developed decreased respiratory rate or apnea (RR≤ 8 bpm or respiratory arrest time≥ 15 s) was 0,40％ and 80％,respectively.Conclusion Although dexmedetomidine induces no respiratory depression,dexmedetomidine can enhance the potency of propofol required for inducing respiratory depression and the prtency is lower than that of small-dose fentanyl.

Objective To investigate the effect of dexmedetomidine on median effective target effect-site concentration ( EC50) of sufentanil inhibiting body movement evoked by skin incision in patients undergoing bilateral subtotal thyroidectomy. Methods Thirty-nine ASA I or II patients of both sexes aged 20-64 yr with a body mass index of 20-25 kg/m2 undergoing bilateral subtotal thyroidectomy were randomly divided into 2 groups: control group (group C) and dexmedetomidine group (group D). The patients were premedicated with intramuscular phenobarbital 0.1 g and scopolamine 0.3 mg. In group D dexmedetomidine 0.6 μg/kg was injected iv over 10 min at S min before induction of anesthesia. Anesthesia was induced with target-controlled infusion (TCI) of propofol and sufentanil. The target plasma concentration of propofol was set at 3.0 μg/ml which was maintained until the end of operation. TCI of sufentanil was started at 10 min after initiation of propofol TCI. The initial target effect-site concentration was set at 0.20 ng/ml and decreased/increased by 20% in the next patient according to whether the patient's body moved or not within 1 min after skin incision. Laryngeal mask airway was inserted at 3 min after initiation of sufentanil TCI. Spontaneous breathing was maintained. Skin incision was made at 10 min after initiation of sufentanil TCI. The EC50 and 95% confidence interval (CI) of sufentanil inhibiting skin incision-evoked body movement were calculated with sequential method. Results EC50, of sufentanil was 0.1148 ng/ml (95% CI 0.1055-0.1249 ng/ml) in group D and 0.1454 ng/ml (95% CI 0.1339-0.1580 ng/ml) in group C, and was significantly lower in group D than in group C. Conclusion Dexmedetomidine 0.6 μg/kg infused iv before operation can reduce the EC50 of sufentanil inhibiting body movement evoked by skin incision in patients undergoing bilateral subtotal thyroidectomy.

Objective To investigate the effect of dexmedetomidine on minimum alveolar concentration (MAC) of isoflurane required to inhibit the body movement during skin incision. Methods Forty-eight ASA Ⅰ or Ⅱ patients aged 40-60 yr with body mass index of 22-27 kg/m2 undergoing elective upper abdominal surgery under general anesthesia were randomly divided into 3 groups: control group (group C, n = 15);low dose dexmedetomidine group (group D1, n = 17) and high dose dexmedetomidine group (group D2, n = 16). The patients were unpremedicated. Dexmedetomidine 0.4 and 0.8 μg/kg in normal saline (NS) 15 ml was infused over 15 min before induction of anesthesia in D1 and D2 groups respectively. Anesthesia was induced with fentanyl-propofol-succinylcholine. The patients were mechanically ventilated after tracheal intubation. Anesthesia was maintained with isoflurane. MAC of isoflurane was determined by up-and-down technique. The initial end-tidal isofiurane concentration was set at 1.0%, 0.8% and 0.6% in C, D1 and D2 groups respectively. Each time the end-tidal isoflurane concentration was increased/decreased by 0.2%. Skin incision was made after 15 min of equilibration, when the twitch height returned to more than 90% of its control value. Movement of body and limbs including swallowing and coughing were carefully looked for when skin incision was made. MAC of isoflurane was the mean of end-tidal concentration of isoflurane of each crossover pair, and 95 % CI was calculated. Results MAC of isoflurane was significantly decreased in D1 and D2 groups as compared with group C and in group D2 as compared with group D1( P ＜ 0.05 or 0.01 ). Conclusion Dexmedetomidine can significantly decrease MAC of isoflurane required to inhibit the body movement during skin incision in a dose-dependent manner.

BACKGROUND:Transfusion guidelines pointed out:whole blood should be stored at (4±2)℃. The bacterial growth or loss of function should occur if the blood leaves the suitable storage conditions. Recipients wil suffer from different degrees of blood transfusion reaction or invalid infusion.
OBJECTIVE:To observe morphology of erythrocytes of autologous blood stored at different temperatures using microscope.
METHODS:Blood was obtained from 40 cases of acute normovolemic hemodilution and stored in ACD citrate bags. Whole blood was respectively stored at 4 ℃ and 23 ℃. Blood smear was taken respectively in the blood storage immediately, 1, 2, 3, 4, 5 and 6 hours after col ecting autologous blood. Changes in morphology of erythrocytes were observed with a microscope. Deformity rate of erythrocytes was calculated. Six blood samples were randomly selected to test pH, K+, and free hemoglobin respectively in 6-hour common temperature group and ACD banked blood within the valid period. Six blood samples were randomly selected for the bacterial culture in each group of two groups at 6 hours.
RESULTS AND CONCLUSION:There were no significant differences in abnormality rates of erythrocytes between 4 ℃ and common temperature groups at each time point. The pH, K+, free hemoglobin at six hours in the common temperature group were better than those of ACD banked blood within the valid period and there was no bacterial growth in culture between the two groups. Therefore, it is feasible to transfuse autologous blood back to the patient within 6 hours of storage at room temperature.

Objective To determine the half-effective target effect-site concentration (Ce) (EC50) of sufentanil required to inhibit the body movement during insertion of ureteroscopes when combined with propofol in patients undergoing transureteroscopic holmium laser lithotripsy. Methods Fifty ASA Ⅰ or Ⅱ patients of both sexes, aged 20-60 yr, BMI ＜ 30 kg/m2 , undergoing transureteroscopic holmium laser lithotripsy were randomly divided into 5 groups according to the different C es of sufentanil ( n = 10 each): group S1 (Ce 0.21 ng/ml), group S2(Ce 0.14 ng/ml), group S3(Ce 0.09 ng/ml), group S4(Ce 0.06 ng/ml), group S5(Ce 0.04 ng/ml). TCI of propofol with target plasma concentration set at 2.5-3.0 μg/ml was given. Sufentanil with the corresponding Ce was infused in each group. The ureteroscopes were inserted as soon as the patients lost consciousness and the effect-site concentration of sunfentanil was achieved. The response was defined as positive when body movement occurred within 1 min after insertion of ureteroscopes. The EC50 of sufentanil required to inhibit the body movement during insertion of ureteroscopes when combined with propofol and 95% confidence interval (CI) were calculated. Results The EC50 of sufentanil required to inhibit the body movement during insertion of ureteroscopes when combined with propofol was 0.084 ng/ml and 95% CI was 0.066-0.107 ng/ml. Conclusion The EC50 of sufentanil required to inhibit the body movement during insertion of ureteroscopes was 0.084 ng/ml when combined with propofol.

Objective To investgate the effects of dexmedetomidine combined with small-dose of sufentanil on the hemodynamics during anesthesia induction in patients undergoing off-pump coronary artery bypass grafting.Methods Seventy-five ASA Ⅱ or Ⅲ and NYHA Ⅱ or Ⅲ patients aged 46-72 yr,weighing 59-86 kg,ejection fraction ≥45％,undergoing off-pump coronary artery bypass grafting,were randomly divided into 3 groups ( n =25):dexmedetomidine combined with small-dose of sufentanil group (group DS),small-dose of sufentanil group (group S1 ) and large-dose of sufentanil group (group S2 ).In group DS,dexmedetomidine 0.8 μg/kg (diluted with normal saline to 15 ml) was injected for 15 min at a rate of60 ml/h,while the same volume of normal saline were given in groups S1 and S2.Anesthesia was induced with midasolam 0.08 mg/kg and pipecuronium 0.12 mg/kg.After administration of the total dose of 1/3 midazolam and 1/8 pipecuronium,sufentanil 0.5,0.5 and 0.8μg/kg (diluted with narmalsaline to 10 ml) were injected in groups DS,S1 and S2 respectively.Then the rest of midazolam was injected.When BIS value ≤ 75,the rest of pipecuronium was injected.When BIS value ≤ 55,the patients were tracheal intubated and mechanically ventilated.PETCO2 was maintained at 30-35 mm Hg.The adverse ardiovascular events (hypertension,hypotension,tachycardia and bradycardia) and drugs intervention were recorded during anesthesia induction.Results Compared with group S2,the incidence of hypertension and tachycardia was significantly increased in group S1,the incidence of hypotension decreased in groups S1 and DS,the incidence of drug intervention decreased in group DS (P ＜ 0.05).Compared with group S1,the incidence of hypertension,hypotension and tachycardia was significantly decreased,the incidence of bradycardia increased,theincidence of drug intervention decreased in group DS (P ＜ 0.05).Conclusion Dexmedetomidine (0.8 μg/kg) combined with small-dose of sufentanil (0.5 μg/kg) is beneficial for keep the stable of hemodynamics during anesthesia induction in patients undergoing off-pump coronary artery bypass grafting.

Objective To investigate the effect of different doses of dexmedetomidine on the median effective concentration (EC50) of propofol required to prevent the response to Supreme laryngeal mask airway (LMA) insertion in aged patients.Methods ASA Ⅰ or Ⅱ patients of both sexes,aged ≥ 65 yr,with a body mass index of 20-28 kg/m2,undergoing knee operation under general anesthesia,were randomly divided into 3 groups:control group (group C),small dose dexmedetomidine group (group D1 ) and large dose dexmedetomidine group (group D2 ).Dexmedetomidine 0.4 and 0.8 μg/kg were infused intravenously over 10 min in groups D1 and D2 respectively,while group C received the equal volume of normal saline instead.Anesthesia was induced with target-controlled infusion of propofol.The initial target plasma concentration of propofol was set at 3.5,3.0 and 2.6 μg/ml in groups C,D1 and D2 respectively.Following equilibration between the plasma and effect-site concentration of propofol,LMA was inserted when BIS value was 50-60.EC50 was determined by up-and-down sequential trial.The target plasma concentration of propofol increased/decreased by 10％ in the next patient depending on whether or not the LMA insertion response occurred.Positive LMA insertion response was defined as body movement,comer of the mouth movement,biting LMA,bucking and/or wallowing during insertion.The EC50 and 95％ confidence interval (CI) of propofol required to prevent LMA insertion response were calculated with sequential method.Results EC50(95％ CI) of propofol was 3.57 μg/ml (2.91-3.87 μg/ml),3.09 μg/ml (2.66-3.53 μg/ml) and 2.62 μg/ml (2.30-3.15 μg/ml) in groups C,D1 and D2 respectively.EC50 was significantly lower in groups D1 and D2 than in group C,and in group D2 than in group D1 ( P ＜ 0.05 ).Conclusion Dexmedetomidine 0.4 and 0.8 μg/kg infused intravenously can reduce the EC50 of propofol required to prevent the response to Supreme LMA insertion in aged patients,and the effect of 0.8 μg/kg is more obvious.

Objective To evaluate the effects of dexmedetomidine on hemodynamics during induction of anesthesia in the patients with atrial fibrillation with rapid ventricular rate undergoing noncardiac surgery.Methods Fifty patients with rheumatic valvular heart disease complicated with atrial fibrillation,aged 45-64 yr,weighing 50-75 kg,with ventricular rate ≥ 90 bpm,of ASA physical status Ⅱ or Ⅲll (NYHA Ⅱ or Ⅲ),scheduled for elective surgery,were randomly divided into 2 groups (n =25 each) using a random number table:control group (group C) and dexmedetomidine group (group D).Dexmedetomidine 0.6 μg/kg was infused intravenously at 10 min prior to induction of anesthesia in group D.Anesthesia was induced with iv midazolam 0.06 mg/kg,sufentanil 0.6 μg/kg,and vecuronium 0.12 mg/kg.Tracheal intubation was performed when the BIS value≤≤ 55After admission to operating room (T0,baseline),immediately after the end of dexmedetomidine infusion (T1),immediately before intubation (T2),and at 1,3 and 5 min after intubation (T3-5),SP,DP,MAP and HR were recorded.The adverse cardiovascular events were recorded starting from induction of anesthesia to 5 min after intubation.Results Compared with the baseline value at T0,HR was significantly decreased at T2,5,while increased at T3,4 in group C,and HR was decreased at T1-5 in group D; SP,DP and MAP were decreased at T2,5,while increased at T3 in group C,and no significant changes were found in the indices mentioned above in group D.Compared with group C,the incidence of hypotension,hypertension and tachycardia was significantly decreased,and no significant changes were found in theincidence of bradycardia in group D.Conclusion Dexmedetomidine 0.6 μg/kg infused intravously is helpful in maintaining the hemadynamics stable during induction of anesthesia in the patients with atrial fibrillation with rapid ventricular rate underging noncardiac surgery.