A formalized safety system for closed-loop anesthesia with pharmacokinetic and pharmacodynamic constraints

Closed-loop anesthesia drug delivery systems can reduce the effect of inter-patient variability, minimize variability in desired clinical effects, and ultimately improve patient safety. Feasibility of closed-loop anesthesia has been clinically evaluated in a number of studies. To obtain regulatory approval to use closed-loop anesthesia as a clinical device, patient safety must be demonstrated. Safety systems for closed-loop anesthesia have been proposed to limit anesthetic concentrations in the plasma and effect-site. Such safety systems minimize the risk of drug under/overdosing. Anesthetic drugs have serious side effects and can significantly reduce blood pressure, thereby jeopardizing patient safety. This paper discusses a safety system that includes safety constraints on blood pressure in addition to the plasma and effect-site concentrations. The proposed safety system is formalized using formal model verification techniques. The performance of closed-loop anesthesia in the presence of constraints on the plasma and effect-site concentrations as well as blood pressure is shown using simulation results. The effectiveness of the proposed safety system is also illustrated in simulation using a realistic clinical scenario. This paper shows that maintaining blood pressure within safety constraints increases the time for anesthesia induction, especially for patients whose blood pressure is more sensitive to anesthetics. For this population, clinical intervention such as administration of vasoactive drugs may be required to counter the effect of propofol on blood pressure during closed-loop anesthesia to achieve a safe yet sufficiently fast induction. This paper extends a previously published formalized safety system which guarantees that the plasma and effect-site concentrations remain within safety limits (Yousefi et al., 2017).     

Fractional order model reference adaptive control for anesthesia

The design of a fractional order model reference adaptive control for anesthesia based on a fractional order model is proposed in the paper. This model gets around many difficulties in controller designs based on the pharmacokinetic/pharmacodynamic model, commonly used for anesthesia for theses purposes, and allows to design a simple adaptive controller with stability and positivity of the system ensured via Lyapunov analysis. Also, the convergence of the tracking error to zero is established by applying an extension of the Barbalat lemma, proven in the paper. Simulations illustrate the effectiveness and robustness of the proposed control.     

右美托咪定联合舒芬太尼术后镇痛效果及安全性的观察

目的：观察右美托咪定与舒芬太尼联合用于全身麻醉患者术后镇痛效果及安全性。方法将120例行全身麻醉手术的患者术后根据镇痛药物不同分为研究组和对照组,每组60例。研究组给予盐酸右美托咪定＋枸橼酸舒芬太尼＋高乌甲素＋雷莫司琼进行静脉自控镇痛（PCIA）,对照组给予枸橼酸舒芬太尼＋高乌甲素＋雷莫司琼进行 PCIA。观察2组患者 T0（术后30 min）、T1（术后2 h）、T2（术后4 h）、T3（术后12 h）、T4（术后24 h）、T5（术后48 h）的 Ramsay 镇静评分情况;采用疼痛视觉模拟量表（VAS）对患者各时间点的疼痛情况进行评定;住院期间观察2组患者不良反应（恶心、呕吐、呼吸抑制以及寒战等）发生情况。结果研究组在 T0、T1、T2、T3及 T4时VAS 评分均明显低于对照组（均 P ＜0．05）。T5时2组患者 VAS 评分比较差异无统计学意义（P ＞0．05）。2组T0、T1、T2、T3、T4及 T5各时间点 Ramsay 镇静评分比较差异均无统计学意义（均 P ＞0．05）。研究组不良反应发生率为8．33％,对照组不良反应发生率为11．67％,2组比较差异无统计学意义（P ＞0．05）。结论右美托咪定与舒芬太尼联合用于全身麻醉患者,术后镇痛效果良好,且无明显不良反应。     

阿是穴激光麻醉拔牙术

采用阿是穴加合谷穴激光麻醉拔牙２８０例，恒牙优良率为７８．８％，乳牙为９３．３％，临床说明此法切实可行，且简单地掌握，效果良好，文中还探讨了激光穴位麻醉拔牙的局限性。     

Fuzzy control of neuromuscular block during general anesthesia—system design,development and implementation

We present a system for fuzzy control of neuromuscular block during general anesthesia. The system (Relax 2005) was clinically used in 50 patients undergoing neurosurgical intervention. From the medical point of view, the benefit of using this system is twofold. First, the workload of the anesthetist is reduced. Second, the efficacy of muscle relaxant administration is improved. As far as medical costs are concerned, using the system decreases the expenditure on muscle relaxants. We describe the design, development, and implementation of the system as well as the results of clinical tests.     

靶控丙泊酚复合罗哌卡因局部浸润麻醉在先天性腭裂修复术中的应用

目的探讨靶控丙泊酚复合罗哌卡因局部浸润麻醉在先天性腭裂修复术中的应用。方法将40例ASAⅠ-Ⅱ级的先天性腭裂病人按随机数字表分为2组：A组和B组,每组20例。A组采用传统的静吸复合全身麻醉,B组采用靶控丙泊酚复合罗哌卡因局部浸润麻醉。结果 A组在T1-T4中SBP、DBP、HR值与B组比较差异均有统计学意义（均P〈0.05）,而B组SBP、DBP一直很平稳,拔管时无明显波动。B组苏醒时间明显短于A组（P〈0.05）,B组误吸及苏醒时烦躁的发生率与A组比较差异均有统计学意义（均P〈0.01）。结论靶控丙泊酚复合罗哌卡因局部浸润麻醉可以使病人术中生命体征更平稳,苏醒更快,且无苏醒期病人烦躁及误吸的现象。     

麻醉诱导气管插管对动脉粥样硬化危险因素者动脉舒张功能的影响

目的：通过肱动脉内皮依赖性扩张功能（Endotheliud—dependent dilation,EDD）的检则,探讨静脉麻醉药物诱导和气管插管与动脉粥样硬化危险因素患者动脉内皮舒张功能的关系。方法：采用B型超声检测合并动脉粥样硬化危险因素的全静脉麻醉手术患者61名,测定麻醉诱导前和诱导插管后肱动脉内皮依赖性扩张功能。结果：诱导插管后,肱动脉内皮依赖性扩张功能为6．23％±1．16％,较诱导前7．05％±1．48％有统计学差异（P〈0．01）。结论：麻醉秀导期合并有动脉粥样硬化危险因素的患者动脉内皮功能显著降低。     

丙泊酚复合麻醉在小儿肠镜检查术的应用

目的探讨丙泊酚复合小剂量瑞芬太尼在儿童纤维结肠镜肠检查中的镇痛镇静效果。方法50例1～10岁患结肠息肉儿童,ASAI～Ⅱ级。术前30min予东蓑若碱0.0lmg/kg肌肉注射先给予2%利多卡因lmg/kg静脉推注缓解丙泊酚的注射痛,给予丙泊酚3mg/kg静脉推注诱导,8mg/kg·h。术中监测BP、HR、RR、sPO2,观察麻醉效果、麻醉时间、苏醒时间及不良反应。结果本组均顺利检查,麻醉效果满意,手术时间(20.8±6.2)min,术后苏醒时(0.2±4.6)min,未发现不良反应。结论在充分给氧的条件下,丙泊酚复合小剂量瑞芬太尼应用于小儿纤维结肠镜肠下治疗结肠息肉麻醉效果可靠,患儿苏醒快、安全、经济,具有较大的使用价值。     

Interactions of team mental models and monitoring behaviors predict team performance in simulated anesthesia inductions.

In the present study, we investigated how two team mental model properties (similarity vs. accuracy) and two forms of monitoring behavior (team vs. systems) interacted to predict team performance in anesthesia. In particular, we were interested in whether the relationship between monitoring behavior and team performance was moderated by team mental model properties. Thirty-one two-person teams consisting of anesthesia resident and anesthesia nurse were videotaped during a simulated anesthesia induction of general anesthesia. Team mental models were assessed with a newly developed measurement tool based on the concept-mapping technique. Monitoring behavior was coded by two organizational psychologists using a structured observation system. Team performance was rated by two expert anesthetists using a performance-checklist. Moderated multiple regression analysis revealed that team mental model similarity moderated the relationship between team monitoring and performance; a higher level of team monitoring in the absence of a similar team mental model had a negative effect on performance. Furthermore, team mental model similarity and accuracy interacted to predict team performance. Our findings provide new insights on factors influencing the relationship between team processes and team performance in health care. When investigating the effectiveness of a specific team coordination behavior, team cognition has to be taken into account. This represents a necessary and compelling extension of the popular process-outcome relationship on which previous teamwork research in health care has focused. Moreover, the current study adds further external validity to the concept of team mental models by highlighting its usefulness in health care. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

高强度聚焦超声（HIFU）治疗儿童实体瘤的麻醉分析

目的：探讨高强度聚焦超声（HIFU）治疗儿童实体瘤麻醉方法及特点。方法：回顾性分析16例HIFU治疗儿童实体瘤的麻醉方法,采用丙泊酚、咪达唑仑、瑞芬太尼和顺式阿曲库胺静脉复合,间断吸入七氟烷,气管内插管控制呼吸,术中持续监测BP、HR、ECG、SpO2、PETCO2及鼻咽温。记录麻醉诱导时、手术开始、术中1h、结束前1h及清醒拔管后的BP、HR及动脉血气。结果：16例患儿血流动力学稳定,各时点血气分析正常。麻醉时间184min至648min（330±42）min,苏醒时间3min至11min（5±3.2）min;无1例并发症发生。结论：静吸复合、气管插管全麻是高强度聚焦超声治疗儿童实体瘤安全有效的麻醉方法。