Objective:To develop a model of stellate ganglion block (SGB) in mice and investigate the effect of SGB on cerebral cortical blood flow.Methods:Thirty clean-grade healthy male C57BL/6 mice, aged 8-9 weeks, weighing 23-27 g, were divided into 5 groups ( n=6 each) using a random number table method: control group (group C), left SGB group (group L), left normal saline group (group SL), right SGB group (group R) and right normal saline group (group SR). Group C received no intervention.SGB was performed with 0.25% ropivacaine 0.08 ml via percutaneous posterior approach in L and R groups, while the equal volume of normal saline 0.08 ml was given instead at the location of left and right stellate ganglion in SL and SR groups, respectively.The cerebral cortical blood flow was determined using laser speckle contrast imaging system before SGB (T 0) and at 10, 30, 60, 90 and 120 min after SGB (T 1-5). Results:Mice developed ptosis on the block side, indicating that the model of SGB was successfully developed in L and R groups.There was no significant difference in cerebral cortical blood flow at each time point among C, SL and SR groups ( P>0.05), and cerebral cortical blood flow on the block side decreased at T 1, began to increase at T 2, peaked at T 3, and decreased at T 5 which was still higher than that at T 0 in group L and group R ( P<0.01). Compared with C and SL groups, the left cerebral cortical blood flow was significantly decreased at T 1, 5 and increased at T 2-4 in group L ( P<0.01). Compared with C and SR groups, the right cerebral cortical blood flow was significantly decreased at T 1, 5 and increased at T 2-4 in group R ( P<0.01). There were no significant differences in cerebral cortical blood flow at each time point between group C and group SL and between group C and group RL ( P>0.05). Conclusions:The mouse model of SGB via percutaneous posterior approach is successfully developed.Unilateral SGB can affect cerebral cortical blood flow on the block side, which shows a transitory decrease followed by a sustained significant increase.

Objective:To evaluate the effect of age on mood of patients during induction of general anesthesia with remimazolam.Methods:Eighty American Society of Anesthesiologists physical status Ⅰ or Ⅱpatients of both sexes, undergoing elective surgery with general anesthesia requiring tracheal intubation, aged 5-80 yr, with body mass index 18-30 kg/m 2, were divided into 4 groups ( n=20 each) according to different ages: juvenile group (R 1 group, 5-17 yr), youth group (R 2 group, 18-44 yr), middle-aged group (R 3 group, 45-59 yr) and elderly group (R 4 group, 60-80 yr). Remimazolam was intravenously injected in a loading dose of 0.1 mg/kg for induction of general anesthesia, followed by an infusion of 0.1 mg·kg -1·h -1 for maintenance of general anesthesia, and the other anesthetics for induction and maintenance of anesthesia were all the same in each group.The changes in emotion and brain wave within 3 min after remimazolam injection were recorded.The brain waves and Modified Observer′s Assessment of Alertness and Sedation (MOAA/S) scale score were recorded at 1, 2 and 3 min after administration.Adverse effects during anesthesia induction were also recorded. Results:Compared with group R 1, the incidence of happy mood was significantly decreased, the grade of mood was decreased, and the dream Likert score and MOAA/S score were decreased in R 3 and R 4 groups, and the dream Likert score and MOAA/S score were decreased in group R 2, and the incidence of hypoxemia during induction of general anesthesia was increased in group R 4( P<0.01). Compared with group R 2, the incidence of happy mood was significantly decreased in R 3 and R 4 groups, and MOAA/S score was significantly decreased in group R 4 ( P<0.05). Compared with R 1 and R 2 groups, the proportion of beta bands was significantly decreased, and the proportion of theta and delta bands was increased in R 3 and R 4 groups ( P<0.01). Compared with group R 3, the proportion of beta band was significantly decreased, and the proportion of delta band was increased in group R 4 ( P<0.01). Conclusion:Remimazolam 0.1 mg/kg used for induction of general anesthesia can cause happy mood, accompanied by enhanced brain electrical signal activity of beta band, especially in the patients under 45 yr of age.