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Objective]To investigate the change of spinal pro?inflammatory cytokines in a rat model of fentanyl induced acute hyperalgesia.[Methods]64 male SD rats were divided into 2 groups(n=32),fentanyl group and NS group. The rats were subcutaneously injected with fentanyl (60 μg/kg) or normal saline (1.2 mL/kg) 4 times with 15?minute intervals. Mechanical nociceptive thresholds and thermal nociceptive latency were measured via the tail pressure test(Tail flick thresholds,TFT) and paw withdrawal test(Paw withdrawal latency,PWL)on the day before,at 1,2,3,and 4 hour and on 1~5 day after injection. 4 rats were killed concomitantly and the lumber spinal cord were harvested to analysis the expression of NF-κB,PGE2,TNF-α,IL-1β,and IL-6.[Results]There were no significant changes of TFT,PWL and the expression of spinal inflammatory cytokines such as NF-κB, PGE2,IL-1β,and TNF-αcompared to baseline of rats treated with normal saline. The value of TFT ,PWL in fentanyl group raised to the highest(above the baseline)at the 1st hour after fentanyl injections and decreased thereafter,reached the lowest at the 1st day, raised increasinglyand up to baseline on the 3 day after injection. NF-κB,PGE2,IL-1β,and TNF-αincreased at the 4th hour,on 1 and 2 day and IL-6 increased at the 4 hour and onthe 1 day after fentanyl injections.[Conclusion]Subcutaneously injection of fentanyl induced significant mechanical and thermal hyperalgesia and increased spinal pro?inflammatory cytokines parallelly , indicated that fentanyl induced acute hyperalgesia is associated with spinal inflammatory reaction in rats.
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Objective To investigate the expression of pro-inflammatory cytokines in lumbar dorsal root ganglions (DRG) of rats model of high-dose fentanyl induced hyperalgesia. Methods 64 male SD rats were divided into 2 groups (n = 32), fentanyl group and normal saline (NS) group. The rats were injected with fentanyl (60 μg/kg) or NS 4 times in total subcutaneously with a 15-minute interval. Mechanical and thermal nociception were measured via the tail pressure test (tail flick thresholds, TFT) and paw withdrawal test (paw withdrawal latency, PWL) at 1 day before, at 1, 2, 3 and 4 hour and on 1 ~ 7 day after administration. 4 rats were sacrificed and the lumbar DRG were harvested to analyze the expression of PGE2 , IL-1β, IL-6 and TNF-αvia ELISA. Results There were no significant changes of TFT, PWL and the expression of pro-inflammatory cytokines in DRG compared to baseline of rats in NS group. The value of TFT , PWL in fentanyl group were above the baseline at the 1 ~ 4 hour and below the baseline at 1~3 day after fentanyl injections. PGE2 , IL-1β, TNF-α and IL-6 increased on 1,3,5,7 day after fentanyl injections significantly. Conclusions High-dose fentanyl induced significant hyperalgesia and up-regulation of pro-inflammatory cytokines in DRG. The expression pro-inflammatory cytokines peaked later and were more protracted than the change of behavior test and show no direct relationship between the two.
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Objective To evaluate the impact of epidural anesthesia with levobupivacaine combined with general anesthesia on colon surgery. Methods Sixty patients undergoing elective radical procedure for colon carcinoma were randomLy divided into four groups: saline group (group S), 0.125% levobupivacaine group (group L1), 0.25% levobupivacaine group (group L2), and 0.5% levobupivacaine group (group L3). Group S received normal saline of 10 mL epidurally and then infusion of 5 mL·h-1 until the procedure was finished; groups L1, L2, and L3 received levobupivacaine instead. Anesthetic induction was performed after epidural puncture. Mean blood pressure and heart rate were recorded at 8 time points including 5 min after entering into the operation room, 1 min after intubation, skin incision, abdominal exploration, 1 h after skin incision, completion of operation, extubation, and leaving PACU; meanwhile blood glucose and cortisol were detected, anesthesia time, time to PACU stay, bleeding, transfusion volume, adverse reaction, and doses of propofol, remifentanil, ephedrine, and fentanyl were noted. Results Time to PACU stay was longer in S group than in other 3 groups. Doses of remifentanil and fentanyl were larger in L1 group than in L2 group and L3 group. Ephedrine dose in L3 group was larger than in other 3 groups. Blood sugar in L1 group was higher than L2 group and L3 group. Cortisol in S group was higher than in other 3 group. Cortisol in L1 group was higher than in L3 group. The number of patients with hypotension was greater in L3 group than other 3 groups. Conclusions Continue epidural infusion of 0.25%levobupivacaine can reduce stress response and opioid uses, shorten PACU stay, whereas it does not increase use of ephedrine.
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Objective To investigate the inhibitant effects of parecoxib, a cyclooxygenase-2 (COX-2) inhibitor, in acute fentanyl induced hyperalgesia in rats. Methods (1) Thirty SD rats (n=6 for each group) were subcutaneously injected with fentanyl (40 μg/kg × 4 times with a 15 min-interval) or saline to establish acute fentanyl induced hyperalgesia model, andparecoxib (5, 10 mg/kg) was administrated intraperitoneally in parecoxib group. Mechanical nociceptive thresholds were measured by the tail pressure test every hour during 1~4 hours and once a day during 1~5 days. (2) 24 SD rats (n = 6 foreach group) were subcutaneously injected with fentanyl as above described and randomly administrated intraperitoneally with parecoxib in 10 mg/kg in 15 min before and at the 4th hour and the 1st day after fentanyl injection except rats in the control group, mechanical nociceptive thresholds were measured by the tail pressure test at time points as above described. Results (1)Acute high dose fentanyl injection induced mechanical hyperalgesia and parecoxib (at 5 or 10 mg/kg)inhibited fentanyl induced hyperalgesia in rats. (2)Parecoxib inhibited fentanyl induced hyperalgesia at 15 min before and at the 4th hour after, but not on the 1st day after fentanyl injection. Conclusions This study provides the first evidence that subanalgesia doses of parecoxib had inhibitory effects on acute fentanyl induced hyperalgesia in time-dependent manners in rats.
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Objective To evaluate the efficacy of anesthesia with different doses of dexmedetomidine combined with propofol and remifentanil in patients undergoing abdominal surgery.Methods Ninety ASA Ⅰ or Ⅱ patients of both sexes,aged 18-64 yr,weighing 45-80 kg,undergoing abdominal surgery,were randomly assigned into 3 groups ( n =30 each):control group (group C ),dexmedetomidine 0.25 μg· kg-1 · h-1 group ( group D1 ) and dexmedetomidine 0.50 μg· kg-1·h-1 group (group D2 ).Dexmedetomidine was infused at a rate of 0.25 μg·kg-1 ·h-1 and 0.50 μg·kg-1 ·h-1 in groups D1 and D2 respectively until extubation after a loading dose of 0.5 μg/kg over 15 min.In group C,normal saline was infused intravenously at a rate of 10 ml/h.Anesthesia was induced with TCI of propofol with the target plasma concentration (Cp) of 1.0 μg/ml,iv injection of cisatracurium 0.2 mg/kg and TCI of remifentanil with Cp of 3 ng/ml.The patients were tracheal intubated and mechanically ventilated.PETCO2 was maintained 35-40 mm Hg and SpO2 was maintained ≥95％.Anesthesia was maintained with TCI of remifentanil with the target Cp of 5 ng/ml,iv infusion of cisatracurium 0.1 mg· kg-1 · h-1 and TCI of propofol.The target Cp of propofol was increased to maintain Narcotrend index of 37-46.The amount of remifentanil,cisatracurium and propofol consumed,extubation time and eye-opening time,complications during operation and during recovery from anesthesia were recorded.Results There was no significant difference in the amount of remifentanil and cisatracurium consumed and extubation time among the three groups ( P ＞ 0.05).Compared with group C,the eye-opening time was significantly prolonged,the incidence of hypertension and tachycardia during operation,and restlessness,vomitting,hypertension,and tachycardia during recovery from anesthesia was significantly decreased in groups D1 and D2,and the amount of propofol consumed was significantly decreased in group D2 (P ＜ 0.05).Compared with group D1,the eye-opening time was significantly prolonged,the incidence of hypertension during operation,and restlessness,hypertension,and tachycardia during recovery from anesthesia was significantly decreased in group D2 ( P ＜ 0.05).Conclusion When combined with propofol and remifentanil,dexmedetomidine infused at a rate of 0.50 μg·kg-1 · h-1 can provide satisfactory efficacy for abdominal surgery.