Bispectral Index Analysis of Opioid Immobilization of Rocky Mountain Elk

Abstract: We immobilized elk with either isoflurane to produce general anesthesia (control), 0.01 mg/kg carfentanil plus 0.1 mg/kg xylazine, or 0.25 mg/kg butorphanol plus 0.4 mg/kg azaperone plus 0.15 mg/kg medetomidine (BAM) and measured the bispectral index (BIS). The carfentanil-xylazine BIS (70.4 + 1.4) and the BAM BIS (60.2 + 1.5) were higher than the control BIS (47.2 + 4.1; P ≤ 0.001). These data indicate that opioids produce neuroleptanalgesia and not general anesthesia or sedation, which explains observed elk responses to these drugs.     

EFFECTIVE, FIELD-BASED INHALATION ANESTHESIA FOR ICE SEALS

Thirty five adult crabeater seals ( Lobodon carcinophaga ) were anesthetized with combinations of the sedative midazolam and the gaseous anesthetic isoflurane during three research cruises to the Antarctic Peninsula (∼67°S, 67°W) in the austral winters of 2001 and 2002. Modifications were required to gas anesthetic equipment to achieve field portability and sufficient heating to allow operations in temperatures as low as -20°C. Seals were sedated with an average intramuscular dose of midazolam of 0.55 ± 0.14 mg/kg delivered via a pole syringe ( n = 32). One seal was not given midazolam and two seals were injected intravenously. Premedication with midazolam provided moderate sedation, making capture and masking practical and safe. Mean induction time with isoflurane was 8 ± 4.8 min. Mean maintenance concentration over the anesthetic period were 2.3%± 0.9% of isoflurane. Average recovery time was 18.2 ± 8.8 min. No substantial difficulties were experienced and anesthetics were easily managed. This drug combination and the use of modified, heated equipment provide an effective anesthetic procedure for crabeater seals.     

静脉全麻联合超声引导下前锯肌平面+肋间神经阻滞应用于胸腔镜肺楔形切除术效果分析

摘要 目的：探讨静脉全麻联合超声引导下前锯肌平面+肋间神经阻滞应用于胸腔镜肺楔形切除术效果。方法：选择2021年10月至2022年12月来我院诊治的60例行胸腔镜肺楔形切除术患者,根据随机数字表法,将60例患者分为对照组（30例）与观察组（30例）,对照组30例患者行全麻联合胸椎旁阻滞+肋间神经阻滞的麻醉方法,观察组30例患者行全麻联合前锯肌＋肋间神经阻滞的麻醉方法。对比两组患者监测入室时（T0）、插管即刻（T1）、手术切皮时（T2）、拔管即刻（T3 ）时的平均动脉压及心率,对比两组患者术后2 h、4 h、12 h、24 h、48 h的静息、咳嗽状态下的疼痛评分,对比两组患者T0-T3点的应激反应指标,对比两组患者术中血管活性药的使用剂量,对比两组患者围术期的不良反应发生率。结果：与T0点相比,观察组在T1、T2、T3时的平均动脉压、心率均有明显增加（P<0.05）,而在T1点时,两组比较无差异（P>0.05）;T2、T3点时观察组的平均动脉压、心率明显较对照组低（P<0.05）。随着术后时间延长,两组静息、咳嗽状态下的疼痛评分明显降低（P<0.05）,而同时间点组间对比无统计学意义（P>0.05）。与T0点相比,观察组在T1、T2、T3时的肿瘤坏死因子、白介素6、白介素10水平均有明显增加（P<0.05）,而同时间点观察组与对照组对比无统计学意义（P>0.05）。观察组术中血管活性药的使用剂量明显较对照组低（P<0.05）。观察组的不良反应发生率16.77%低于对照组23.33%,但组间对比无统计学意义（P>0.05）。结论：行静脉全麻联合超声引导下前锯肌平面+肋间神经阻滞的胸腔镜肺楔形切除术者血流动力学更加稳定,术中所需血管活性药物用量明显降低。     

Anesthesia and post-mortem interval profoundly influence the regulatory serine phosphorylation of glycogen synthase kinase-3 in mouse brain

Glycogen synthase kinase-3 (GSK3) is a crucial enzyme contributing to the regulation of neuronal structure, plasticity and survival, is implicated as a contributory factor in prevalent diseases such as Alzheimer's disease and mood disorders and is regulated by a wide range of signaling systems and pharmacological agents. Therefore, factors regulating GSK3 in vivo are currently of much interest. GSK3 is inhibited by phosphorylation of serine-9 or serine-21 in GSK3beta and GSK3alpha, respectively. This study found that accurate measurements of phospho-Ser-GSK3 in brain are confounded by a rapid post-mortem dephosphorylation, with approximately 90% dephosphorylation of both GSK3 isoforms occurring within 2 min post-mortem. Furthermore, three anesthetics, pentobarbital, halothane and chloral hydrate, each caused large in vivo increases in the serine phosphorylation of both GSK3beta and GSK3alpha in several regions of mouse brain. Thus, studies of the phosphorylation state of GSK3 in brain, and perhaps in other tissues, need to take into account post-mortem changes and the effects of anesthetics and there is a direct correlation between anesthesia and high levels of serine-phosphorylated GSK3.     

A phospholipid sensor controls mechanogating of the K+ channel TREK-1

TREK-1 (KCNK2 or K(2P)2.1) is a mechanosensitive K(2P) channel that is opened by membrane stretch as well as cell swelling. Here, we demonstrate that membrane phospholipids, including PIP(2), control channel gating and transform TREK-1 into a leak K(+) conductance. A carboxy-terminal positively charged cluster is the phospholipid-sensing domain that interacts with the plasma membrane. This region also encompasses the proton sensor E306 that is required for activation of TREK-1 by cytosolic acidosis. Protonation of E306 drastically tightens channel-phospholipid interaction and leads to TREK-1 opening at atmospheric pressure. The TREK-1-phospholipid interaction is critical for channel mechano-, pH(i)- and voltage-dependent gating.     

Phase-transition-driven synaptic exocytosis: a hypothesis and its physiological and evolutionary implications

It is proposed that the plasma membrane in the active zones of synaptic terminals contains self-assembling cooperative domains whose Ca2+-induced solidification may be the driving force of the fast neurotransmitter release in the central synapses. This hypothesis and a qualitative model of the phase-transition-driven exocytosis provide formulation of a unitary approach to a number of general problems in the physiology of animals. It allows answering the following questions, among others: (i) What is the physical reason for the existence of a narrow optimum range of body temperatures in warm-blooded species? (ii) What is the physical reason for the inevitable necessity of regular sleep in animals? (iii) Does there indeed exist any general mechanism of general anesthesia?     

外科动物实验中猪的麻醉问题

猪作为重要的实验动物,在外科实验中运用传统的麻醉方法时易引起呼吸道阻塞而死亡,我们使用全麻插管技术,并辅以术前术后各种对症处理,成功地解决了手术中猪因呼吸道阻塞而死亡的问题。     

Drug Effects on the Release of Endogenous Acetylcholine In Vivo: Measurement by Intracerebral Dialysis and Gas Chromatography–Mass Spectrometry

Intracerebral microdialysis was combined with a sensitive and specific gas chromatographic-mass spectrometric assay to measure the release of endogenous acetylcholine in the rat striatum in vivo. In rats anesthetized with urethane (1.2 g/kg i.p.), the levels of striatal acetylcholine dialyzed into a Ringer's perfusate were: (a) reliably measurable only in the presence of physostigmine; (b) stable at between 3 and 8 h of perfusion (30-75 pmol/20 min in the presence of 75 microM physostigmine); (c) reduced by calcium-free Ringer's solution, tetrodotoxin (0.1 microM), and vesamicol (1.0 microM); and (d) increased by elevated potassium (100 mM), atropine (3-300 microM), and haloperidol (0.75 mg/kg i.p.). In conscious unrestrained rats, the spontaneous release of striatal acetylcholine was not altered significantly following the administration of urethane. The changes in acetylcholine release observed in this study are consistent with the known actions of some drugs or ionic conditions on striatal cholinergic neurotransmission and are evident under the condition of urethane anesthesia. The present results demonstrate the sensitivity and suitability of this method for monitoring endogenous striatal acetylcholine release in vivo.     

围术期手术麻醉安全体系的构建

麻醉安全性在增加,但围术期仍存有诸多挑战。“外科手术的围术期医疗模式 新策略的提出,期望有助于提高医疗质量、降低医疗成本。麻醉医师应该主动迎接时代挑战,承担起学科发展的历史使命,通过调整专业定位、规范医疗行为、加强病人安全管理建设,来构建起围术期手术麻醉的安全体系。     

小剂量右美托咪定用于局麻下玻璃体切割术的镇静效果观察

目的:探讨右美托咪定用于局麻下玻璃体切割术的镇静效果。方法:选择拟在局麻监测下行玻璃体切割术患者50例为研究对象,年龄20-72岁,ASA分级Ⅱ级~Ⅲ级,随机分为右美托咪定组(D组)和咪达唑仑组(M组),每组25例。D组患者于术前10min静脉泵注右美托咪定0.5μg/kg,后以0.2-0.4μg/kg.h的速度持续输注,M组术前10 min缓慢静脉注射咪达唑仑0.02 mg/kg,术中按需静注0.5 mg/次。维持VAS评分≤4分,Ramsay评分2-4分。记录和比较两组患者术中血压、心率、呼吸的变化、辅助用药及患者对镇静效果的满意度。结果:给药后,M组T5时点MAP较T0显著下降(P0.05),D组T10及以后各时点MAP较T0显著下降(P0.05);D组T5及以后各时点BP较T0显著下降(P0.05),但组间及M组组内BP比较差异无统计学意义(P0.05);M组T30时点HR较T0显著下降(P0.01),而在T5时,组间比较差异有统计学意义(P0.01),即D组下降更为显著。给药后各时点,D组VAS评分均显著低于M组(P0.05),30 min时达最低。两组Ramsay镇静评分给药后5 min均达2级以上,与给药前比较均显著升高(P0.05),D组给药后30 min及以后各时点Ramsay镇静评分均显著高于M组(P0.01)。给药后各时点,两组组内和组间SPO2和RR比较均无统计学差异(P0.05)。D组患者满意度较M组更高(P0.05)。结论:小剂量右美托咪定用于玻璃体切割术可使患者血流动力学平稳,镇静效果良好,疼痛感觉减轻,舒适度提高。