ABSTRACT
Objective To evaluate the effect of dexmedetomidine on the long-term sensorimotor gating system after sevoflurane anaesthesia in neonatal rats.Methods One hundred forty-four clean-grade healthy male Sprague-Dawley rats,aged 4-6 days,weighing 8-15 g,were divided into 4 groups (n =36 each) using a random number table method:control group (group C),sevofluraue group (group S),dexmedetomidine plus sevoflurane group (group D + S),and dexmedetomidine plus α2 receptor antagonist atipamezole plus sevoflurane group (group D+A+S).In group S,anesthesia was induced with 6％ sevofluraue for 3 min and maintained with 2.1％ sevoflurane,and the anesthesia time was 6 h in total.Dexmedetomidine 25 μg/kg was intraperitoneally injected in group D.In group D +A+ S,dexmedetomidine 25 μg/kg and atipamezole 250 μg/kg were intraperitoneally injected,and the other treatments were similar to those previously described in group S.Twelve rats in each group were randomly selected after anesthesia and sacrificed,and blood samples were collected for determination of serum corticosterone concentrations by enzyme-linked immunosorbent assay.Twenty-four rats were randomly selected in each group,and prepulse inhibition (PPI) of startle test was performed at 70 days after birth.PPI rate (PP3％,PP6％,PP12％) was calculated.The serum corticosterone concentration was measured by restraint stress test on 80 days after birth.Results There was no significant difference in PP6％ or PP12％ among the four groups (P＞0.05).Compared with group C,PP3％ was significantly decreased,and the serum corticosterone concentration was increased after the end of anesthesia and during restraint stress test at 80 days after birth in S and D+A+ S groups (P＜0.05),and no significant change was found in the parameters mentioned above in group D (P＞0.05).Compared with group S,PP3％ was significantly increased,and the serum corticosterone concentration was decreased after the end of anesthesia and during restraint stress test at 80 days after birth in group D (P＜0.05),and no significant change was found in the parameters mentioned above in group D+ A+S (P＞0.05).Compared with group D,PP3％ was significantly decreased,and the serum corticosterone concentration was increased after the end of anesthesia and during restraint stress test at 80 days after birth in group D+A+S (P＜0.05).Conclusion Dexmedetomidine can alleviate the damage to long-term sensorimotor gating system after sevoflurane anesthesia in neonatal rats,and the mechanism may be related to activating central α2 receptors and improving hypothalamic-pituitary-adrenal axis hyperfunction.
ABSTRACT
Objective To evaluate the effect of bilateral thoracic paravertebral block (TPVB) combined with general anesthesia on early recovery after Nuss procedure in patients with pectus excavatum.Methods Sixty patients of both sexes with pectus excavatum,aged 8-18 yr,with body mass index＜ 18.5-32.0 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,scheduled for elective Nuss procedure,were divided into 2 groups by using a random number table method:general anesthesia group (group GA,n=30) and bilateral TPVB combined with general anesthesia group (group TPVB+ GA,n=30).Bilateral TPVB was performed at the level of T5 under ultrasound guidance at 30 min before operation in group TPVB+GA.Anesthesia was induced by intravenous injection of fentanyl,propofol and rocuronium and maintained by inhalation of sevoflurane,intravenous infusion of remifentanil 0.1-0.5 μg · kg-1 · min-1,and intermittent intravenous boluses of rocuronium.Patients received patient-controlled intravenous analgesia after operation.Tramadol 1-2 mg/kg or dizocin 0.1 mg/kg was intravenously injected as rescue analgesic,maintaining visual analogue scale score ≤ 3 within 2 days after operation.The intraoperative consumption of remifentanil,postoperative consumption of snfentanil,requirement for rescue analgesia and development of nausea and retching/vomiting were recorded.Quality of recovery was assessed using the Quality of Recovery-15 at 1 and 2 days after operation.Results Compared with group GA,the intraoperative consumption of remifentanil,postoperative consumption of sufentanil,rate of rescue analgesia and incidence of nausea and vomiting were significantly decreased,and Quality of Recovery-15 scores were increased at 1 and 2 days after operation in group TPVB +GA (P＜0.05).Conclusion Bilateral TPVB combined with general anesthesia can reduce the perioperative consumption of opioids and is beneficial for the early recovery after Nuss procedure in patients with pectus excavatum.
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Objective To evaluate the effect of dexmedetomidine on sevoflurane anesthesia-in-duced cortical epileptiform electroencephalogram ( EEG) activity in the neonatal rats. Methods Forty clean-grade healthy Sprague-Dawley rats, aged 4-6 days, weighing 8-15 g, were divided into 5 groups (n＝8 each) using a random number table method: control group ( C group), sevoflurane group ( S group), dexmedetomidine plus sevoflurane group (D+S group), dexmedetomidine plus alpha 2-adrenocep-tor antagonist atipamezole plus sevoflurane group (D+A+S group), and atipamezole plus sevoflurane group (A+S group). After the electrode was correctly placed, the EEG was continuously monitored, and normal saline 5 μl∕g was intraperitoneally injected at 58 min of monitoring in group C, dexmedetomidine 25 μg∕kg was intraperitoneally injected in group D+S, dexmedetomidine 25 μg∕kg and atipamezole 250 μg∕kg were intraperitoneally injected in group D+A+S, and atipamezole 250 μg∕kg was intraperitoneally injected in group A+S. Anesthesia was induced by inhaling 6% sevoflurane for 3 min starting from 60 min of monitoring and then maintained by inhaling 2. 1% sevoflurane for 1 h. The total duration, the number and average du- ration of epileptic waves were recorded during anesthesia. Blood samples were obtained from the left ventri-cle after the end of anesthesia for blood gas analysis. Rats were then sacrificed and blood samples were col-lected for measurement of the serum corticosterone concentration. Results No epileptic wave was found in group C. The serum concentration of corticosterone was significantly higher in the other four groups than in group C ( P＜0. 05). Compared with group S, the total duration of epileptic wave was significantly short-ened, the number of epileptic wave was reduced, and the concentration of corticosterone was decreased in group D+S (P＜0. 05), and no significant change was found in the total duration, the number and average duration of epileptic waves or serum concentration of corticosterone in D+A+S and A+S groups (P＞0. 05). Compared with group D+S, the total duration of epileptic wave was significantly prolonged, the number of epileptic wave was increased, and the serum concentration of corticosterone was increased in D+A+S and A+S groups (P＜0. 05). Conclusion Dexmedetomidine can inhibit the occurrence of cortical epileptiform EEG activity induced by sevoflurane anesthesia in the newborn rats, and the mechanism may be related to improving the hypothalamus-pituitary-adrenocortical axis hyperfunction mainly through activating the central 2-adrenoceptor.
ABSTRACT
Objective To evaluate the effect of dexmedetomidine on the long-term anxiety state after sevoflurane anesthesia in neonatal rats and the role of different central subtypes of α2 receptors.Methods A total of 216 clean-grade healthy male Sprague-Dawley rats,aged 4-6 days,weighing 8-15 g,were divided into 6 groups (n =36 each) using a random number table method:control group (group C),sevoflurane group (group S),dexmedetomidine + sevoflurane group (group D+S),dexmedetomidine + α2 receptor antagonist atipamezole + sevoflurane group (group D+A+S),dexmedetomidine + α2A receptor antagonist BRL44408 + sevoflurane group (group D+B+S),and dexmedetomidine + α2C receptor antagonist JP1302 + sevoflurane group (group D+J+S).Anesthesia was induced by inhaling 6％ sevoflurane for 3 min and maintained by inhaling 2.1％ sevoflurane for 6 h.At 30 min before anesthesia induction,dexmedetomidine 25 μg/kg was intraperitoneally injected in group D+S,dexmedetomidine 25 μg/kg and atipamezole 250 μg/kg were intraperitoneally injected in group D + A + S,dexmedetomidine and α2A receptor antagonist BRL44408 1.5 mg/kg were intraperitoneally injected in group D+B+S,and dexmedetomidine 25 μg/kg and α2C receptor antagonist JP1302 3 mg/kgwere intraperitoneally injected in group D+J+S.Twelve rats in each group were randomly selected and sacrificed after the end of anesthesia,blood samples were collected for blood gas analysis,and the serum corticosterone concentration was measured by enzyme-linked immunosorbent assay.The elevated plus maze was performed when the left rats in each group were 60 days old,and 12 rats were selected when the they were 80 days old to perform the restraint stress test.Results Compared with group C,the percentage of time of staying at the open arm was significantly decreased,the total motion distance was shortened,and the serum corticosterone concentration was increased after the end of anesthesia and during the restraint stress test in S,D+A+S and D+B+S groups (P＜0.05),and no significant change was found in the parameters mentioned above in D+S and D+J+S groups (P＞0.05).Compared with group S,the percentage of time of staying at the open arm was significantly increased,the total motion distance was prolonged,and the serum corticosterone concentration was decreased after the end of anesthesia and during the restraint stress test in group D+S and group D+J+S (P＜0.05),and no significant change was found in the parameters mentioned above in group D+A+S and group D+B+S (P ＞0.05).Compared with group D+S,the percentage of time of staying at the open arm was significantly decreased,the total motion distance was shortened,and the serum corticosterone concentration was increased after the end of anesthesia and during the restraint stress test in D+A+S and D+B+S groups (P＜0.05),and no significant change was found in the parameters mentioned above in group D+J +S (P＞ 0.05).Conclusion Dexmedetomidine can reduce the long-term anxiety state after sevoflurane anesthesia in neonatal rats,and the mechanism may be related to activating central α2A receptors and improving hypothalamic-pituitary-adrenocortical axis hyperfunction.