BACKGROUND: It has been reported that the ischemia preconditioning (IPC) had credible protective efficiency on ischemic injury of the spinal cord during aorta operation, but the mechanism of the protective efficiency of IPC had not been clarified.OBJECTIVE: To study the protective effects of repetitive IPC on ischemic injury of spinal cord and its mechanism in rabbits.DESIGN: A completely randomized controlled study based on the experimental animals.SETTING: Department of anesthesiology in a university hospital.MATERIALS: The experiment was completed in the Department of Anesthesiology, Renmin Hospital, Wuhan University during September and December 2002. Twenty-four Japanese rabbits were randomly and double-blindly divided into sham-operation group, ischemia-reperfusion group and IPC group with 8 rabbits in each group.INTERVENTIONS: In sham-operation group, abdominal aorta was not clamped. Spinal cord ischemia was induced by infra-renal aortic cross-clamp for 45 minutes in ischemia-reperfusion group. Before the 45 minutes ischemia, the rabbits in the IPC group underwent four cycles of ischemia preconditioning, i.e. clamping abdominal aorta for 5 minutes then reperfusion for 5 minutes.MAIN OUTCOME MEASURES: The concentrations of calcium, magnesium, copper and zincum in spinal cord were measured in the 7th day after operation. Postoperative neurological function, EMG of rear limb, and spinal cord histopathological changes were assessed in all groups after operation.RESULTS: The concentrations of calcium and copper in spinal cord in ischemia-reperfusion group were significantly higher than those in sham-operation group( P ＜ 0. 05 or 0. 01 ), but magnesium and zincum significantly lower( P ＜ 0. 05). Compared with IPC group, calcium in ischemia-reperfusion group was significantly higher( P ＜ 0.01 ), but zincum significantly lower( P ＜ 0.01 ) . The neurological function and histopatholohical changes in ischemia-reperfusion group were much lower than those in sham-operation group and IPC group ( P ＜ 0.05 or P ＜ 0.01) . And there was significantly worse change of EMG in ischemia-repeffusion group than that in IPC group(P ＜ 0.01).CONCLUSION: Repetitive ischemic preconditioning can protect rabbit spinal cord from ischemia reperfusion injury quickly, and one possible reason for its protective effect is to maintain the balance of calcium, magnesium,copper and zincum in ischemic region.

Objective:To compare the sedative effect and safety of different doses of dexmedetomidine in the patients undergoing total abdominal hyserectomy. Methods:A total of 120 patients undergoing total abdominal hysterectomy were randomly divided into four groups, different doses of dexmedetomidine groups(D1 group, D2 group and D3 group)and midazolam group(M group) with 30 pa-tients in each. Dexmedetomidine groups received intravenous pump infusion of dexmedetomidine (0. 5 μg·kg-1 ) 10 minutes before the operation, and then the different dexmedetomidine groups were received continuous infusion of dexmedetomine of different doses:D1 group of 0. 4μg·(kg·h) -1, D2 group with 0. 6μg·(kg·h) -1 and D3 group with 0. 8μg·(kg·h) -1;M group received in-travenous pump infusion of midazolam (0. 06 mg·kg-1) 10 minutes before the operation, and then with 0. 04 mg·(kg·h) -1 con-tinuous infusion. The mean arterial pressure( MAP) , heart rate( HR) , respiratory rate( RR) , oxyhemoglobin saturation( SpO2 ) were recorded at the following time points:the moment of entering the operating room(T0), the block effect of epidural anesthesia was satis-fied (T1),10 min(T2),20 min(T3)and 40 min(T4)after the drug infusion, and the end of the operation(T5), and the duration of the medicine use and the whole operation were recorded as well. The sedation degrees were evaluated with Ramsay scale, and the am-nesic scores, adverse drug reactions and patient satisfaction were recorded after the operation. Results:Compared with that of the other groups, HR of D3 group was obviously lower after T3 (P<0. 05);and after T2, HR was significantly lower than that at T0 (P<0. 05 or P<0. 01). Compared with the other groups, RR of M group was obviously lower at T3 and T4 (P<0. 05). Compared with those at T0 , the sedative effects of all the groups were much remarkable(P<0. 05 or P<0. 01);and the Ramsay score of D3 group at T3 and T4 was higher than that in D1 group or M group(P<0. 05). There were no obvious adverse reactions in the four groups. Conclusion:The use of dexmedetomidine in the patients undergoing total abdominal hyserectomy might not lead to the risk of respiratory depression as the use of midazolam, while the dose of dexmedetomidine should be less than 0. 8 μg·(kg·h) -1.

Objective:To compare the effect of lightwand guided tracheal intubation in difficult airway between waking state and intravenous anesthesia induced state. Methods:According to the random number table, 78 cases of difficult airway patients were di-vided equally into waking group and intravenous anesthesia induction group . The changes of vital signs, the time of tracheal intubation and the extubation complications after 1 h were compared between the groups. Results:Compared with the corresponding values of the waking group, the blood pressure and heart rate before and after the tracheal intubation significantly increased in the intravenous anes-thesia induction group (P<0. 05 or P<0. 01). In the same group, the blood pressure and heart rate increased significantly after the tracheal intubation when compared with those before the treatment (P<0. 05 or P<0. 01). Compared with that in the intravenous an-esthesia induction group, the time of tracheal intubation was significantly shorter in the waking group (P<0. 01), and the 24h postop-erative anesthesia satisfaction was improved significantly (P<0. 05). Conclusion: Compared with intravenous anesthesia induction, waking lightwand guided tracheal intubation in the patients with difficult airway has more advantages.

Objective:To investigate the physical and mental health of trainees receiving standardized residency training of anesthesiology in four large teaching hospitals in Wuhan, China, as well as related risk factors.Methods:The trainees who received standardized residency training of anesthesiology in four large general teaching hospitals in Wuhan were selected as subjects, and Symptom Checklist-90 (SCL-90) and Eysenck Personality Questionnaire were used to investigate mental health and personality state. SPSS 22.0 was used to perform the independent samples t-test, a one-way analysis of variance, and the chi-square test, and Logistic regression was used to analyze the influencing factors for SCL-90. Results:A total of 328 questionnaires were distributed and 326 valid questionnaires were collected, with a recovery rate of 99.39%. Among these trainees, 68 (20.86%) were found to have abnormal mental status (SCL-90 score >160), with a relatively high proportion of the trainees with obsessive-compulsive symptoms or depression. The trainees with abnormal mental status showed the personality characteristics of tendency neuroticism and tendency psychoticism, and compared with the trainees with normal mental status, the trainees with abnormal mental status showed a higher proportion of trainees with abnormal personality characteristics. The univariate analysis showed that the grade of residency training, scientific research pressure, monthly on-duty frequency, and personality characteristics were associated with abnormal mental status, and the multivariate analysis showed that a monthly on-duty frequency of >5 times ( B=0.997, odds ratio [ OR]=2.709, 95%CI: 1.051-6.986, P=0.039), great pressure of scientific research ( B=3.235, OR=25.412, 95%CI: 3.239-199.363, P=0.002), emotional instability ( B=2.015, OR=7.504, 95%CI: 3.529-15.954, P<0.001), and psychosomatic abnormalities ( B=1.640, OR=5.154, 95%CI: 2.510-10.581, P<0.001) were risk factors for psychological abnormality in trainees, while extroversion personality ( B=-2.758, OR=0.063, 95%CI: 0.019-0.215, P<0.001) was a protective factor against abnormal mental status. Conclusions:The positive rate of psychological abnormality is 20.86% among trainees receiving standardized residency training of anesthesiology in four large teaching hospitals in Wuhan, and possible influencing factors include monthly on-duty frequency, scientific research pressure, work pressure, and different personality characteristics.