Objective To explore the long-term effects of dexmedetomidine on the brain development in propofol-induced neonatal rats.Methods Thirty-five seven-day-old Sprague-Dawley rats of both genders,weighing 10-15 g,were randomly divided into seven groups (n =5) using a random number table:normal saline group (group N),intralipid group (group F),propofol 100 mg/kg group (group P),dexmedetomidine 75 μg/kg (group D),dexmedetomidine 25 μg/kg,50 μg/kg and 75μg/kg+propofol 100 mg/kg groups (groups PD25,PD50 and PD75),neonatal rats in each group were treated according to the corresponding dosing regimen.After fully awake,the rats were allowed to mature until postnatal week 9 and the spatial learning and memory capacities were tested by Morris water maze.The rats were sacrificed after the tests.Brain was sliced for determination of hippocampal apoptosis by TUNEL assays and the expression of postsynaptic density protein 95 (PSD95) by immunohistochemistry.Results Compared with group N,the escape latency was significantly prolonged,the times of platform crossing were significantly decreased,the hippocampal apoptosis ratio was significantly increased and the expression of PSD95 was significantly down-regulated in groups P,PD25 and PD50 (P＜0.05).Compared with group P,the escape latency was significantly shortened,the times of platform crossing were significantly increased and the hippocampal apoptosis were significantly decreased in groups PD50 and PD75 (P＜0.05),the expression of PSD95 was up-regulated in group PD75 (P＜0.05).Compared with group PD25,the escape latency was significantly shortened,the number of platform crossing was significantly increased and the hippocampal apoptosis were significantly decreased in groups PD50 and PD75 (P＜0.05),the expression of PSD95 was significantly up-regulated in group PD75 (P＜0.05).Compared with group PD50,the hippocampal apoptosis were significantly decreased,the expression of PSD95 was significantly up-regulated in group PD75 (P＜ 0.05).Conclusion The addition of dexmedetomidine 50,75 μg/kg attenuates propofol-induced neurocognitive impairment in neonatal rats after aducthood,partially by attenuating hippocampal apoptosis and upregulating the expression of PSD95.Dexmedetomidine alone was not neurotoxic to the developing brain.
Objective To investigate the optimal dose of dexmedetomidine （DEX） combined with sufentanil 0.3μg·kg-1 for anesthesia of radio frequency ablation（RFA）for liver cancer geriatrics.Methods Our study was a random,single blind one.Sixty patients of both sexes,males 53 and females 7,aged 65-84 years,BMI 18.1-35.4 kg/m2,falling into ASA physical statusⅡ orⅢ and Child-Pugh class A or B,scheduled for elective RFA for liver cancer,were randomly assigned into 3 groups（n =20 each）.All groups received different dose of DEX and 0.3μg/kg sufentanil infused 20 minutes before RFA surgery:group D1 (DEX 0.3μg·kg-1·h-1),group D2(DEX 0.5μg·kg-1·h-1),and group D3(DEX 0.7μg·kg-1·h-1).Ramsay sedation score were recorded at the following time points:patients entered into the operating room （T0）,20 minutes after DEX infused （T1）,ablation beginning（T2）,10 minutes after ablation beginning （T3） and the end of operation （T4）.Visual analogue scale（VAS）was recorded at T4,and 2,4,8,12 hours after the ablation respectively.The dosages of etomidate,nitroglycerin,urapidil,and naloxone were noted.The complications and side effects were also noted.The complications of intraoperative awareness,respiratory obstruction,puncture needle displacement,and submembrane hematoma of the liver,and the adverse reaction of hypertention,hypotension and tachycardia were recorded.Results Compare to T0,Ramsay sedation score of groups D2 and D3 at T2-T3 was increased significantly （P <0.05）.Compare to group D1,VAS of groups D2 and D3 at 2,4,8 hours after the ablation were decreased significantly （P < 0.05）.The dosage of etomidate,nitroglycerin,and urapidil in groups D2 and D3 were decreased significantly compare to group D1 （P <0.05）.Compare to group D2,the incidence of intraoperative awareness of group D1 were increased significantly（P < 0.05）,the dose of naloxone of group D3 （70.48±21.38μg）was increased significantly （P < 0.05）,the incidence of transient hypertension,bradycardia and respiratory depression of group D3 were increased significantly （P <0.05）.Conclusion The combination dexmedetomidine 0.5μg·kg-1·h-1 with sufentanil 0.3μg/kg can provide good conscious analgesia,reduce respiratory depression and adverse reactions is a reasonable clinical use for elderly patients under going RFA.
Objective To explore the effect of dexmedetomidine on phosphoinositide 3-kinase/protein kinase B (PI3K/Akt ) pathway in hippocampus of propofol anesthetized neonatal rats. Methods Eighty Sprague-Dawley male rats,aged 7 days,weighing 10-1 5 g,were randomly divided into 8 groups (n= 10 each):normal saline group (group N),DMSO group (group D),intralipid group (group I),propofol group (group P),dexmedetomidine 25 μg/kg,50 μg/kg and 75 μg/kg +propofol 100 mg/kg groups (groups PD25 ,PD50 and PD7 5 ),LY294002 25 μg + dexmedetomidine 75μg/kg + propofol 100 mg/kg group (group LYPD).The hippocampus of rats in all groups were taken 2 h after the animals fully awake.The ultrastructure of hippocampal neurons was observed by transmission electron microscope.The pAkt-(ser473 )protein and Akt protein in the hippocampus were evaluated by Western blot analysis.Results There was no significant difference in the expression of Akt protein among the eight groups.Compared with group N,the expression of pAkt (ser473)protein was significantly down-regulated in groups P,PD25 ,PD50 ,PD7 5 and LYPD (P <0.05).Compared with group P,the expression of pAkt (ser473)protein was increased significantly in groups PD7 5 and LYPD (P <0.05).Compared with group PD7 5 ,the expression of pAkt (ser473) protein was significantly down-regulated in group LYPD (P <0.05 ).The structure of hippocampal neurons was normal in groups N,I and D.Nuclear nuclei swelling,chromatin decreasing and mito-chondrion vacuolar degeneration were observed in group P while improved gradually with dexmedeto-midine in a dose-dependent manner in groups PD25 ,PD50 and PD7 5 .Neurons karyopyknosis,partial dissolution of nuclear membrane,chromatin condensation,mitochondria vacuolar degeneration were observed in group LYPD.Conclusion Dexmedetomidine pretreatment provides neuroprotection against propofol-induced hippocampal destruction by preserving PI3K/Akt pathway activity in the de-veloping brains.
Objective To investigate the effect of thoracic paravertebral nerve block on the treatment of refractory angina pectoris.Methods Sixty patients with definite diagnosis of refractory angina pectoris were recruited.They were divided into two groups in order of clinic time:blind paravertebral nerve block group(blind exploration group)and ultrasonic-guided paravertebral nerve block group(ultrasound guidance group),and 15 ml 0.375%ropivacaine was given by single-dose injection respectively at the treatment site in both groups.The effects of treatment were evaluated.The state of angina pectoris,SBP,HR before and 1,24 and 48hafter treatment were recorded.And the myocardial oxygen consumption index(SBP×HR)were calculated.Results Compared with the blind exploration group,the effective rate and total effective rate were significantly higher in ultrasound guidance group(P0.05).Compared with the treatment before,scores of number of angina pectoris attacks and duration,myocardial oxygen consumption index at 24 hafter treatment of the two groups were significantly lower,and that in ultrasound guidance group was significantly lower than that in the blind exploration group(P0.05).Conclusion The effects of thoracic paravertebral nerve block in the treatment of refractory angina pectoris were satisfying,and the outcome was better under ultrasonic guidance.
Objective To determine the Cp50 of propofol by target controlled infusion(TCI)combined with fentanyl in patients with obesity receiving painless colonoscopy.Methods Twentyseven male and twenty-eight female patients who undergoing painless colonoscopy under propofol TCI for sedation were assigned to group N(18.5kg/m2≤BMI24.0kg/m2)or group O(BMI≥28.0kg/m2).In both of the groups,the target plasma concentration of propofol was initially set at 3.0μg/ml and it could be adjusted with a level of 0.5μg/ml(sequential up-and-down methods)based on the physical responses to propofol in the previous patient receiving the same procedure.The Cp50 of propofol and its 95% confidence interval in both of groups were computed.Results When combined with fentanyl(1.0μg/kg),the Cp50 of propofol was 2.95μg/ml in group N and 2.83μg/ml in group O,with a 95% confidence interval of 2.68-3.24μg/ml and 2.62-3.05μg/ml,respectively.Conclusion TCI of propofol combined with 1.0μg/kg fentanyl during colonoscopy in patients with obesity is safe and effective,with the Cp50 of 2.83μg/ml.The Cp50 of propofol in obesity is reduced.
