Another (Internal) Epineurium: Beyond the Anatomical Barriers of Nerves

The epineurium has been accepted as the outer anatomical barrier of the peripheral nerves. Our objective was to characterize the microanatomy of the layers surrounding nerves using different tissue-specific staining methods. Two hundred forty-two cross sections of human sciatic and median nerves, and brachial plexuses of eight fresh unembalmed cadavers, were examined. The samples were fixed in formaldehyde solution and stained with hematoxylin–eosin, Masson's trichrome, or epithelial membrane antigen under standard conditions. Because epithelial membrane antigen only stains the perineurium, we demonstrated using hematoxylin–eosin and Masson's trichrome that there were different collagen layers inside and outside the nerves. All fascicles had a collagen layer that surrounded the perineurium and were in close contact with it, with no adipose tissue between them. Unlike the perineurium, this layer, an “internal epineurium,” contained no cells, and it surrounded one or a small group of fascicles. Bundling these fascicles or small groups of fascicles together was the true epineurium, and between the true and internal epineurium, we consistently found an adipose-containing compartment. More proximal to this, the tibial and common peroneal nerves were bundled together by another collagen layer, the circumneurium, which also had a fat-cell-containing compartment deep to it. There were scattered collagen fibers among the adipocytes. Using tissue-specific staining, we were able to demonstrate a collagen layer, the “internal epineurium.” Outside the nerves, we identified several fat-containing concentric compartments. Those compartments were limited by collagen fiber layers that were also similar to the epineurium. Clin. Anat. 33:199–206, 2020. © 2019 Wiley Periodicals, Inc.     

Upper limb nerve blocks

Brachial plexus blockade is used for a variety of upper limb surgical procedures. Ultrasound guidance is generally considered to be the gold-standard technique, although large-scale studies examining efficacy and complications of ultrasound-guided techniques compared with nerve stimulation are still needed. Interscalene block remains the approach of choice for shoulder surgery, although phrenic nerve blockade is common even using low volumes of local anaesthetic. Of the currently available studies comparing the other approaches, there seems to be little difference in efficacy between axillary, supraclavicular and infraclavicular approaches for elbow, forearm and hand surgery when equivalent levels of expertise are used. The major features influencing block choice and performance are discussed.     

三种不同时机下术前导尿配合手术室护理对全麻手术患者苏醒期躁动的影响

摘要 目的 观察三种不同时机下术前导尿配合手术室护理对全身麻醉（全麻）手术患者苏醒期躁动的影响。方法 选择2017年1月～2018年12月于我院行择期全麻手术的患者100例，根据术前导尿时机分为3组：A组（手术当日清晨在病房导尿，33例）、B组（麻醉前在手术室导尿，30例）、C组（麻醉平稳后在手术室导尿，37例）。记录并比较3组麻醉时间、术中输液量、术中出血量、苏醒时间及导尿前后收缩压（SBP）、舒张压（DBP）及心率（HR）变化，比较3组一次性导尿成功率、术后导尿管适应度及苏醒期躁动发生情况，采用自拟问卷调查患者护理满意度。结果 3组麻醉时间、术中输液量、术中出血量及苏醒时间比较，差异无统计学意义（P>0.05）；A组导尿后SBP、DBP、HR较导尿前均显著升高（P<0.05），B组和C组SBP、DBP、HR与导尿前比较，差异无统计学意义（P>0.05）；A组一次性导尿成功率显著低于B组和C组，术后导尿管适应度显著差于B组和C组（P<0.05）；A组苏醒期躁动发生率显著高于C组，苏醒期躁动分级显著高于C组P<0.05）；A组护理满意度评分显著低于B组和C组，差异有统计学意义（P<0.05）。结论 在麻醉前后于手术室进行导尿的效果明显优于手术当日清晨在病房导尿，配合手术室护理干预可有效提高患者术后对导尿管的适应度，降低苏醒期躁动发生率，提高患者护理满意度。     

骨科下肢手术中应用不同剂量的右美托咪定辅助低位硬膜外麻醉对术中、术后不良反应的影响

目的探讨骨科下肢手术中应用不同剂量的右美托咪定辅助低位硬膜外麻醉对术中、术后不良反应的影响。方法选取我院90例骨科下肢手术患者,依据右美托咪定用药剂量分为甲组、乙组及丙组,各30例;选取同期于我院行生理盐水辅助低位硬膜外麻醉的30例骨科下肢手术患者为对照组。比较四组患者不良反应发生情况、镇静情况及认知功能。结果丙组不良反应总发生率高于甲组、乙组和对照组(P<0.05)。用药10 min(T1)、30 min(T2)、60 min(T3)及120 min(T4)时,甲组、乙组、丙组的Ramsay镇静评分均高于用药前(T0),且均高于对照组,同时乙组高于甲组,丙组高于甲组和乙组(P<0.05)。术后次日,甲组、丙组的MMSE评分均低于术前,且均低于乙组和对照组(P<0.05)。结论骨科下肢手术患者行右美托咪定辅助低位硬膜外麻醉时,右美托咪定的泵注量选择0.6μg/kg可达到较佳麻醉效果。     

高频超声诊断不同臂丛神经病变研究进展

臂丛神经结构复杂，走形迂曲，位置表浅，支配上肢及肩部的运动及感觉。随着科学技术的发展，臂丛神经损伤呈现逐年上升的趋势。如何对臂丛神经损伤做出及时且精准的诊断，术前明确区分节前与节后损伤，一直是近年来临床研究的热点、难点。本文旨在重点介绍高频超声在不同臂丛神经病变诊断中的研究进展。     

Safety of Transesophageal Echocardiography to Guide Structural Cardiac Interventions

BackgroundDespite the widespread use of transesophageal echocardiography (TEE) to guide structural cardiac interventions, studies evaluating safety in this context are lacking.ObjectivesThis study sought to determine the incidence, types of complications, and factors associated with esophageal or gastric lesions following TEE manipulation during structural cardiac interventions.MethodsThis was a prospective study including 50 patients undergoing structural cardiac interventions in which TEE played a central role in guiding the procedure (mitral and tricuspid valve repair, left atrial appendage closure, and paravalvular leak closure). An esophagogastroduodenoscopy (EGD) was performed before and immediately after the procedure to look for new injuries that might have arisen during the course of the intervention. Patients were divided in 2 cohorts according to the type of injury: complex lesions (intramural hematoma, mucosal laceration) and minor lesions (petechiae, ecchymosis). The factors associated with an increased risk of complications were assessed.ResultsPost-procedural EGD showed a new injury in 86% (n = 43 of 50) of patients, with complex lesions accounting for 40% (n = 20 of 50) of cases. Patients with complex lesions presented more frequently with an abnormal baseline EGD (70% vs. 37%; p = 0.04) and had a higher incidence of post-procedural dysphagia or odynophagia (40% vs. 10%; p = 0.02). Independent factors associated with an increased risk of complex lesions were a longer procedural time under TEE manipulation (for each 10-min increment in imaging time, odds ratio: 1.27; 95% confidence interval: 1.01 to 1.59) and poor or suboptimal image quality (odds ratio: 4.93; 95% confidence interval: 1.10 to 22.02).ConclusionsMost patients undergoing structural cardiac interventions showed some form of injury associated with TEE, with longer procedural time and poor or suboptimal image quality determining an increased risk. Imaging experts performing this technique should be aware of the nature of potential complications, to take the necessary precautions to prevent their occurrence and facilitate early diagnosis and treatment.     

Resistencia a los anestésicos locales: ¿verdad o mito?

The report of anesthetic technique failure is crucial and the etiology of the problem should be determined. We describe a case of locoregional anesthesia failure, in which, after excluding its most common causes, the resistance to local anesthetics was considered as the most probable clinical hypothesis. For this reason, a genetic test was performed, as well as the efficacy of other local anesthetics was evaluated, constituting a different approach in the cases of locoregional anesthesia failure. True resistance to local anesthetics is difficult to diagnose so information about this is scarce in the literature. One of the proposed causes is a mutation of sodium channels where local anesthetics bind. If not recognized, the application of locorregional anesthesia in this patient's condition can lead to unpleasant experiences and unnecessary risks, related to toxic levels of local anesthetics. For this reason, the resistance to local anesthetics should be always precluded in cases of strong clinical suspicion. This approach could be applied in similar cases.