局麻药脊髓神经毒性的研究进展

越来越多的实验研究表明局麻药有潜在的神经毒性,脊椎麻醉后神经功能损害可能是由于局麻药的直接毒害作用,但其作用机理尚不清楚。本文就局麻药脊髓神经毒性的研究进展综述如下。     

alpha-Chloralose diminishes gamma oscillations in rat hippocampal slices

alpha-Chloralose is an anesthetic characterized by its ability to maintain animals in physiological conditions though immobilized and anesthetized. In addition, alpha-chloralose induces a loss of consciousness with little influence on either pain response or cardiovascular reflexes. The pharmacological mechanisms of alpha-chloralose's actions are poorly understood. In vitro experiments have demonstrated alpha-chloralose enhances GABA(A) receptor function, which may underlie its anesthetic effect. However, how alpha-chloralose affects hippocampal synaptic function and neuronal network synchronization is unknown. In the present study, we performed electrophysiological recordings to examine the effects of alpha-chloralose on synaptic transmission, tetanic stimulation-induced gamma oscillations (30-80 Hz) and neuronal receptor function in rat hippocampal slices and dissociated hippocampal CA1 pyramidal neurons. The results demonstrated that alpha-chloralose (30-100 microM) diminished tetanic stimulation-induced gamma oscillations without affecting single stimulation-induced field potential responses. In single, dissociated hippocampal CA1 pyramidal neurons, alpha-chloralose activated GABA(A) receptors at a high concentration while it potentiated GABA(A) receptor-mediated currents at low concentrations. However, alpha-chloralose did not affect glutamate-, glycine-, or ACh-induced currents. Slice-patch recordings revealed alpha-chloralose enhanced GABAergic leak current and prolonged the decay constant of spontaneous inhibitory postsynaptic currents (sIPSCs). It is concluded that alpha-chloralose suppresses hippocampal gamma oscillations without significantly affecting basic synaptic transmission or ionotropic glutamate, choline and glycine receptor function. Enhancement of GABAergic leak current and prolongation of GABAergic sIPSCs by alpha-chloralose likely underlie its disruption of neuronal network synchronization in the hippocampus.     

连续周围神经阻滞用于术后镇痛的研究进展

连续周围神经阻滞术后镇痛效果好,副作用少,能够有效地缓解术后疼痛,促进手术后功能恢复,而得到越来越广泛的应用。近年来,神经刺激器、超声引导下定位技术的出现,使得连续周围神经阻滞定位更加准确,技术日趋完善,而对于局部麻醉药的选择、药物浓度等的相关研究使这一技术更加安全,有效。     

七氟醚预处理对大鼠急性肾缺血再灌注损伤肾功能的影响

目的:探讨七氟醚预处理对大鼠急性肾缺血再灌注损伤肾功能的影响。方法:将SD雄性大鼠72只随机分为假手术组(C组)、缺血再灌注组(I/R组)和七氟醚预处理组(S组),每组24只,后两组根据再灌注时间分为再灌注后4、12、24 h 3个亚组,每个亚组8只。实验结束检测血BUN、Cr,观察肾组织的病理变化,对肾小管损害进行评分,并进行比较。结果:S组和I/R组BUN、Cr均较C组明显升高(P<0.05),再灌注后同时相点比较,12h、24h S组BUN、Cr均明显低于I/R组,4h两组差异不显著;肾小管Paller氏评分,与C组相比,I/R、S组均高于C组(P<0.05),S组各时相点评分较I/R组降低(P<0.05)。结论:七氟醚预处理对大鼠急性肾缺血再灌注损伤有保护作用。     

Techniques and complications of popliteal nerve blocks

BackgroundUse of popliteal nerve blocks (PNBs) as an alternative or adjunctive therapy to traditional methods of pain control (e.g., systemic or spinal anesthesia and opioids) is increasingly popular in foot and ankle surgery.MethodsWe reviewed online databases for literature on PNBs in foot and ankle surgery to analyze the various techniques and positioning used, the influence of drugs on their efficacy, and possible complications associated with their use. Thirty articles were identified with a predefined search criteria, followed by a review process for relevance.ResultsPatient demographics, procedure specifics, and block techniques, such as anesthetic used, can impact the duration and success of a PNB. Administration with ultrasound guidance proved superior to nerve stimulation, and preoperative administration was superior to postoperative administration.ConclusionsPNBs are an effective method to control postoperative pain with minimal complications, leading to decreased analgesic use, earlier discharge, and higher patient satisfaction.Level of evidenceLevel III, retrospective comparative study     

紫绀型与非紫绀型先天性心脏病患儿吸入麻醉药血／气分配系数

目的：测定并比较紫绀型与非紫绀型先天性心脏病患儿吸入麻醉药／气分配系数（Ｂ／Ｇ）,判断红细胞压积对Ｂ／Ｇ影响。方法：紫绀型与非紫绀型先天性心脏病患儿各１０例,平均年龄５岁,采桡动脉血１０ｍｌ,用两次平衡法测定地氟醚,异氟醺客氟烷的Ｂ／Ｇ,并测定血浆总胆固醇、甘油三脂,白蛋白、球蛋白浓度和Ｈｃｔ,ｔ检验比较两组间血液成分和吸入麻醉药Ｂ／Ｇ有无差别。结果：紫绀型与非紫绀型先天性心脏病患儿Ｈｃｔ有显著差     

Intrathecal co-administration of NMDA antagonist and NK-1 antagonist reduces MAC of isoflurane in rats

BACKGROUND: Intravenous administration of N-methyl-D-aspartate (NMDA) receptor antagonists and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonists reportedly reduce the minimum alveolar anaesthetic concentration (MAC) for inhalation anaesthetics. If pain perception can be prevented by the intrathecal administration of antinociceptive receptor antagonists, these agents may reduce the requirements for inhalation anaesthetics. We studied the effect of intrathecal administration of an AMPA/kainate receptor antagonist, a metabotropic glutamate (mGlu) receptor antagonist and co-administration of NMDA and a neurokinin-1(NK-1) receptor antagonist drugs at low doses on the MAC. METHODS: After Wistar rats (n=36) were fitted with indwelling intrathecal catheters, the MAC of isoflurane was determined following intrathecal administration of a non-NMDA receptor antagonist (CNQX) at 10 microg, a mGlu receptor antagonist (AP3) at 10 microg, or a combination of NMDA receptor antagonist (APV) at 0.01 microg to 1 microg with NK-1 receptor antagonist (CP96345, CP) at 0.1 microg to 10 microg. Subsequently, a reversal dose of intrathecal NMDA with substance P (SP) was administered, and the MAC of isoflurane was redetermined. Conscious rats (n=15) were also examined for the presence of locomotor dysfunction following the intrathecal co-administration of APV and CP. RESULTS: Neither CNQX nor AP3 reduced the MAC of isoflurane. APV at 0.01 microg plus CP at 1 microg, as well as APV at 0.1 microg plus CP at 10 microg, reduced the MAC of isoflurane, with respective reductions of 7.6% and 14%; (P<0.05). Co-administration of NMDA plus SP reversed the decrease in the MAC of isoflurane. Locomotive activity was not changed. CONCLUSIONS: The NMDA receptor and the NK-1 receptor are important determinants of the MAC of isoflurane, exerting this influence by inhibition of pain transmission in the spinal cord, while mGlu and AMPA receptors have no effect on the MAC of isoflurane.     

窗口版吸入麻醉药生理性隔室药代动力学电脑模型的设计和验证

目的 设计并验证窗口环境下运行的吸入麻醉药生理性隔室药动力力电脑模型,方法模型包含有麻醉环路和肺器官２个气相室和１２个组织室,以Ｒｉｇｇｓ原理描述药物在组织和器官中的处置。屏幕上设有麻醉机和呼吸机的仿真操作面板,同时具有１４个隔室计算结果的图形和数据输出。临床验证分七氟醚（ＳＥＶ）组和地氟醚（ＤＥＳ）组,每组３７例ＡＳＡⅠ～Ⅱ级病人,使用常规的麻醉方法,采集麻醉药呼气末浓度作为靶浓度,将其结果与模