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Objective To evaluate the effects of dexmedetomidine on the expression of neuronal nitric oxide synthase (nNOS) and c-fos in the lcuos cruleus (LC) in a rat model of endotoxic shock.Methods Twentyeight male Sprague-Dawley rats,aged 8 weeks,weighing 250-300 g,were randomly divided into 4 groups (n =7 each):control group (group C),endotoxic shock induced by lipopolysaccharide (LPS) group (group L),lowdose dexmedetomidine group (groupLD) and high-dose dexmedetomidine group (group HD).Normal saline 0.5 ml/kg was injected via the tail vein in C and L groups.Dexmedetomidine 0.5 and 4.5μg/kg were injected via the tail vein in group LD and group HD,respectively.Normal saline 0.5 ml/kg was injected via the tail vein 10 min later in C,while LPS 5 mg/kg was injected intravenously 10 min later in the other groups.The rats were sacrificed and their brains were removed for determination of brain water content,the number of nNOS and c-fos positive cells and expression of nNOS and c-fos in the LC by immuno-histochemistry.Results Compared with group C,the brain water content was significantly increased,the number of nNOS and c-fos positive cells in the LC was enlarged,and the expression of nNOS and c-fos in the LC was up-regulated in group L (P ＜ 0.05).The brain water content was significantly lower,the number of nNOS and c-fos positive cells in the LC was smaller,and the expression of nNOS and c-fos in the LC was lower in LD and HD groups than in group L (P ＜ 0.05).The number of nNOS and c-fos positive cells in the LC was significantly smaller,and the expression of nNOS and c-fos in the LC was lower in HD group than in group LD (P ＜ 0.05).Conclusion Dexmedetomidine can down-regulate the expression of nNOS and c-fos in the LC,which may be one of brain-protective mechanisms of dexmedetomidine in a rat model of endotoxic shock.
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0.05) except during the 24 th hour postoperative period.During the 0.5 h postoperative period,the average total amount of injections of morphine was statistically lower in the ropivacaine group(control 15.8?23.9 ?g/kg versus ropivacaine 2.4?10.9 ?g/kg;P
ABSTRACT
AIM:To observe the efficacy and safety of ropivacaine supplemented with midazolam for sacral block in pediatric operation.METHODS:40 cases of patients aged 1-6 years old,who were going to be operated in hypogastrium,perineum and lower limb,were randomly and double-blindly divided into four groups with ten cases each:control group(bupivacaine 2.5 mg/kg),low dosage group(ropivacaine 2.5 mg/kg),middle dosage group(ropivacaine 3.5 mg/kg)and high dosage group(ropivacaine 5.0 mg/kg).Sacral block was performed after induction of inhalation anaesthesia with sevoflurane.Sedation was induced by midazolam(0.2 mg/kg)administered through mainline 5 min before the surgical procedure.RESULTS:In a certain dosage range,ropivacaine supplemented with midazolam anesthesia for sacral block showed a slight influence on diastolic blood pressure,mean arterial pressure,heart rate and pulse oxygen saturation.Those parameters remained in the physiological normal range,though they dropped slightly during the operative period.Compared with bupivacaine group,the postoperative analgesic period was similar in the high and middle ropivacaine groups,while it was shorter in low ropivacaine group.There was no significant adverse effect in all groups except for operative stretch reflex and postoperative vomiting in individual patients.CONCLUSION:Ropivacaine supplemented with midazolam anesthesia for sacral block has a slight influence on hemodynamics,prolongs the postoperative analgesic period,and shows less adverse effect.