局麻下甲状腺手术对预防喉返神经损伤的优势研究

目的探讨甲状腺手术所致喉返神经损伤的原因及预防措施。方法回顾性分析我科2001年10月至2010年10月手术治疗的甲状腺病变患者300例,随机分为A、B、C3组,每组100例,A组采用局部浸润麻醉,术中不分离喉返神经,语音检测喉返神经是否损伤;B、C2组采用全麻,B组患者术中部分或全部分离喉返神经,C组手术过程中不分离喉返神经,对比分析3组术后喉返神经损伤状况。结果 A组局麻下施行甲状腺手术,不显露喉返神经,术后喉返神经的损伤及并发症的发生情况优于B、C2组。结论用局部麻醉、手术中即时语音检测喉返神经是否损伤,或者术中部分或全部喉返神经分离,是预防喉返神经损伤的有效措施。     

1958例剖宫产术麻醉与术后镇痛的临床分析

目的回顾1958例剖宫产术的麻醉与术后镇痛方法,总结临床经验。方法统计分析1958例剖宫产术实施不同麻醉与术后镇痛方法的麻醉效果、术后镇痛效果、并发症发生率;总结麻醉后并发症如低血压的处理。结果从起效时间看,CEA组比CSEA组、SA组明显较慢,有统计学意义(P<0.01);麻醉效果3组产妇比较无统计学意义;麻醉后SBP下降30mmHg的例数CEA组比CSEA组、SA组较少,有统计学意义(P<0.01);其中各组内使用麻黄素干预与发生麻醉后SBP下降30mmHg后通过快速输液处理的例数比较有统计学意义(P<0.01),表明麻醉后血压下降大多数病例都通过加快输液就能缓解;731例术后镇痛中大多数病例VAS评分均为优良,709例自控镇痛按压次数2～5次不等,发生恶心、呕吐等并发症29例。结论剖宫产手术麻醉及镇痛方法多样,椎管麻醉尤其是腰硬联合麻醉的应用因其效果确切、操作方便、并发症容易处理而且还能实施硬膜外自控镇痛是目前剖宫产手术麻醉的较好方法。     

Isoflurane Potentiation of GABAA Receptors Is Reduced but Not Eliminated by the β3(N265M) Mutation

Background: Mice carrying the GABA_A receptor β3(N265M) point mutation, which renders receptors incorporating β3-subunits insensitive to many general anesthetics, have been used experimentally to link modulation of different receptor subtypes to distinct behavioral endpoints. Remarkably, however, the effect of the mutation on the susceptibility to modulation by isoflurane (a standard reference agent for inhalational vapors) has never been tested directly. Therefore, we compared the modulation by isoflurane of expressed α5β3(N265M)γ2L receptors with their wild type counterparts. Methods: Using whole-cell electrophysiological recording and rapid solution exchange techniques, we tested the effects of isoflurane at concentrations ranging from 80 μM to 320 μM on currents activated by 1 μM GABA. We measured drug modulation of wild-type α5β3γ2L GABA_A receptors and their counterparts harboring the β3(N265M) mutation. Results: Currents elicited by GABA were enhanced two- to four-fold by isoflurane, in a concentration-dependent manner. Under the same conditions, receptors incorporating the β3(N265M) mutation were enhanced by approximately 1.5- to two-fold; i.e., modulation by isoflurane was attenuated by approximately one-half. Direct activation by isoflurane was also present in mutant receptors but also attenuated. Conclusions: In contrast to the complete insensitivity of β3(N265M) mutant receptors to etomidate and propofol, the mutation has only a partial effect on receptor modulation by isoflurane. Therefore, the persistence of isoflurane effects in mutant mice does not exclude a possible contribution of β3-GABA_A receptors.     

麻醉机潮气量的校准比对

为了验证麻醉机的检测方法及可靠程度,以潮气量的校准为例,参考了JJF 1234-2018《呼吸机校准规范》,选取三家计量机构的检测结果进行分析。应用计量比对法验证校准结果的可信程度,接着采用归一化偏差法验证结果的一致性程度。结果表明,潮气量检测的可信程度和一致性程度良好,可为临床检测提供参考。     

不同剂量右美托咪啶预防腰硬联合麻醉下寒战反应的效果

目的: 探讨不同剂量右美托咪啶(Dex)预处理对腰硬联合麻醉下寒战反应的有效性、安全性及最佳剂量。方法: 择期下腹部妇科手术的女性患者120例,ASAⅠ﹣Ⅱ级,年龄33～65岁,采用随机数字表法按术中右美托咪啶微泵维持用量分为4组:D₁组、D₂组、D₃组及对照组C组(生理盐水 20 mL) 。D₁、D₂、D₃组在硬膜外给药结束后输注右旋美托咪啶负荷量1 μg/kg,之后分别以微泵缓慢输注右美托咪啶 0.2(D₁组)、0.4 (D₂组)、0.6 μg/kg (D₃组),C组输注同等容量生理盐水,关腹前停用。纪录患者自麻醉开始到手术结束后有无寒战、寒战发生时间、寒战级别、术中使用麻黄碱和阿托品的比率及并发症。采用BIS监测评估给药前(T₀)、给药后 5 min(T₁)、15 min(T₂)、30 min(T₃)及手术结束时(T₄)患者镇静程度,纪录各时点的鼓膜温度。结果: 4组患者的年龄、身高、体质量及手术时间、麻醉时间均无明显差别(P>0.05)。4组患者各时点的心率(HR)、平均动脉压(MAP)、血氧饱和度(SpO₂)无明显差别(P>0.05)。4组寒战发生率分别为 43.3%、16.6%、6.7% 及40%,4组寒战发生率有统计学差异(P<0.05)。4组低血压的发生率分别为5%、7%、8%、8%,各组之间比较无统计学差异。D₃组与D₁、D₂组比较,阿托品使用比率有明显上升(P<0.05)。与C组比较,前3组术中各时点BIS值有统计学差异(P<0.05)。各组患者的鼓膜温度与术前比较有统计学差异(P<0.05)。结论: 右美托咪啶预处理可明显降低腰硬联合麻醉下寒战反应的发生率,其机制可能与降低中央室寒战温度触发阈值有关。右美托咪啶微泵维持的适宜剂量为 0.4 μg/kg。     

活体运输过程中冰片麻醉剂与MS-222对草鱼麻醉效果的对比研究

为提高水产品活体运输的存活率,文章探明了将传统中药冰片作为麻醉剂应用于水产品活体运输的可能性。对比了不同浓度的MS-222（间氨基苯甲酸乙酯甲磺酸盐,也称“鱼安定”）和冰片麻醉剂对草鱼(Ctenopharyngodon idellus)的麻醉效果,并在30 mg/L的冰片麻醉剂和20 mg/L的MS-222中研究了水温对麻醉效果的影响,最后在20 ℃水温条件下分别在30 mg/L的冰片麻醉剂和20 mg/L的MS-222中进行了麻醉模拟运输试验并对关键生化指标进行比较分析。麻醉试验结果表明：随麻醉剂浓度增加,草鱼进入相同麻醉期时间缩短,完全复苏时间延长,20~40 mg/L的冰片麻醉剂适于草鱼的麻醉运输。麻醉时间随水温降低而缩短,复苏时间随着水温降低而增加,20~25 ℃水温适于草鱼的冰片麻醉运输。麻醉模拟运输试验结果表明：冰片麻醉运输24 h存活率为100%,MS-222麻醉运输24 h存活率为70%。复苏时间随运输时间的增加而增加。冰片麻醉运输各项生化指标均优于MS-222麻醉运输。文章结果显示,在20~25 ℃水温条件下,冰片麻醉运输保活效果优于MS-222。     

Mechanical characterization and drug permeation properties of tetracaine-loaded bioadhesive films for percutaneous local anesthesia

In the development of bioadhesive patch devices for percutaneous local anesthesia, the tensile properties of the films produced after the casting of the gel intermediates is of key importance to the clinical compliance of the product, and its effective delivery of the local anesthetic agent. A range of bioadhesive patches were formulated and their mechanical and in vitro permeation properties determined. Altering formulation significantly altered the mechanical properties of films. The tensile properties of the films could be modified to allow concomitant benefits in the mechanical and drug permeation properties of the films, ensuring that patches not only exerted clinically beneficial effects, but are also mechanically robust. Tetracaine was found to plasticize films and while this effect was weak, it was significant both statistically and potentially also in the effect it has on the clinical use of these devices. Drug release from tetracaine patches demonstrate the same trends as found previously across polydimethylsiloxane films. By altering the formulation of the patch device, the drug release from the device to the skin is readily and accurately controlled, and was not solely a function of the stratum corneum barrier properties but additionally of the formulation.     

基于小波变换的麻醉监测脑电信号的分析与处理

针对中潜伏期听觉诱发脑电的特点，提出了利用小波变换的多分辨分析技术滤除被测信号的强噪声成分，重构真实信号来实现对中潜伏期听觉诱发脑电的提取方法；通过实验仿真表明：小波变换提取技术比其他传统提取方法更有效，可以减少试验次数，可以提供更为可靠的特征提取和模式识别的分析数据，这为麻醉深度的临床监测探索了重要的理论基础。     

Parameter extraction in EEG processing during riskful neurosurgical operations

An advanced methodology of EEG parameter extraction is presented. This has been used during riskful surgical interventions i.e. intracranial aneurysm clipping in controlled hypotension through continuous infusion of sodium nitroprusside, SNP. The signal is processed using an AR-modelling approach and the information is shown in the form of pole diagram, power density spectrum estimation, and plotting of the identification coefficients. Some advantages of the previously reported techniques are discussed in respect to the more traditional approaches (e.g. FFT algorithms). Important applications are also foreseen in the field of neurophysiological research and clinical neurology.     

Adaptive control for nonlinear compartmental dynamical systems with applications to clinical pharmacology

There are significant potential clinical applications of adaptive control for pharmacology in general, and anesthesia and critical care unit medicine in particular. Specifically, monitoring and controlling the levels of consciousness in surgery are of particular importance. Nonnegative and compartmental models provide a broad framework for biological and physiological systems, including clinical pharmacology, and are well suited for developing models for closed-loop control of drug administration. In this paper, we develop a direct adaptive control framework for nonlinear uncertain nonnegative and compartmental systems with nonnegative control inputs. The proposed framework is Lyapunov-based and guarantees partial asymptotic set-point regulation, that is, asymptotic set-point regulation with respect to part of the closed-loop system states associated with the plant. In addition, the adaptive controller guarantees that the physical system states remain in the nonnegative orthant of the state space. Finally, a numerical example involving the infusion of the anesthetic drug propofol for maintaining a desired constant level of consciousness for noncardiac surgery is provided to demonstrate implementation of the proposed approach.