Evaluation and Design of Alphabetic Communication Boards

Communication boards provide a low-cost means of facilitating communication with patients who are unable to speak;however the process is slow and frustrating. A computer model was used to calculate the cumulative frequency-weighted path length for letter selection (“chart index”) for three conventional communication boards using different search strategies;and exhaustively generate and evaluate designs for a novel communication board based on a frequency-ordered arrangement of letters. For all arrangements, a 46% to 53% reduction in chart indices was achieved when “2 Dimensional” (2D) rather than “1 Dimensional” (1D) search strategies were employed. A further 23% to 30% reduction in chart indices was achieved through use of frequency-ordered sequences with optimal row groupings. Conventional communication boards can be used more efficiently by employing a 2D search strategy. Novel communication boards based on optimised arrangements of frequency-ordered letter sequences potentially provide a faster means of communication than conventional communication boards.

全身麻醉药物对发育期大脑影响的争鸣

麻醉药物作用于N-甲基-D-天冬氨酸(NMDA)受体和(或)γ氨基丁酸(GABA)引起发育期动物大脑神经退行性变和成年后认知功能障碍,且神经元凋亡或功能受损具有年龄、接触时间和剂量的依赖性。然而麻醉药物诱导神经细胞凋亡的假说仍存在争议。麻醉药物引起的凋亡是病理性凋亡还是生理性凋亡及其与与神经认知功能障碍间的因果关系尚不清楚。动物实验中不同种属动物麻醉/镇痛所需要的药物剂量、发育易感期各不相同,因此动物实验结果不能直接应用于临床。临床上全麻药物对婴幼儿神经毒性的临床研究证据尚不充分,仍需进一步获取多中心、大样本人类研究数据,以证实麻醉药物与发育期大脑退行性变的因果关系,阐述其机制,指导临床医师的工作。本文综述了全身麻醉药物对发育期大脑影响的研究进展。

一氧化氮——一种特异性肺血管舒张剂研究进展及展望

一氧化氮是一种有害气体.低浓度吸入后可经肺泡弥散于肺血管平滑肌内,从而舒张肺循环血管.弥散于血流的一氧化氮,直接与血红蛋白结合,转化成高铁血红蛋白,使之失活.研究表明,吸入低浓度一氧化氮,可不同程度地降低肺动脉高压.在吸入一氧化氮浓度低于100ppm下,未发现有明显的毒副作用.本文就其研究历史,吸入一氧化氮对肺动脉高压的作用,其选择性作用于肺循环的机理、毒副作用、吸入方法等进行了回顾,并简要地提出尚需解决的问题.一氧化氮可能会成为真正特异性肺血管舒张剂.

Dementia and osteoporosis in a geriatric population: Is there a common link?

AIM To determine the existence of a common pathological link between dementia and osteoporosis through reviewing the current evidence base. METHODS This paper reviews the current literature on osteoporosis and dementia in order to ascertain evidence of a common predisposing aetiology. A literature search of Ovid MEDLINE(1950 to June 2016) was conducted. The keywords "osteoporosis", "osteoporotic fracture", "dementia" and "Alzheimer's disease"(AD) were used to determine the theoretical links with the most significant evidence base behind them. The key links were found to be vitamins D and K, calcium, thyroid disease, statins, alcohol and sex steroids. These subjects were then searched in combination with the previous terms and the resulting papers manually examined. Theoretical, in vitro and in vivo research were all used to inform this review which focuses on the most well developed theoretical common causes for dementia(predominantly Alzheimer's type) and osteoporosis.RESULTS Dementia and osteoporosis are multifaceted disease processes with similar epidemiology and a marked increase in prevalence in elderly populations. The existence of a common link between the two has been suggested despite a lack of clear pathological overlap in our current understanding. Research to date has tended to be fragmented and relatively weak in nature with multiple confounding factors reflecting the difficulties of in vivo experimentation in the population of interest. Despite exploration of various possible mechanisms in search for a link between the two pathologies, this paper found that it is possible that these associations are coincidental due to the nature of the evidence available. One finding in this review is that prior investigation into common aetiologies has found raised amyloid beta peptide levels in osteoporotic bone tissue, with a hypothesis that amyloid beta disorders are systemic disorders resulting in differing tissue manifestations. However, our findings were that the most compelling evidence of a common yet independent aetiology lies in the APOE4 allele, which is a well-established risk for AD but also carries an independent association with fracture risk. The mechanism behind this is thought to be the reduced plasma vitamin K levels in individuals exhibiting the APOE4 allele which may be amplified by the nutritional deficiencies associated with dementia, which are known to include vitamins K and D. The vitamin theory postulates that malnutrition and reduced exposure to sunlight in patients with AD leads to vitamin deficiencies. CONCLUSION Robust evidence remains to be produced regarding potential links and regarding the exact aetiology of these diseases and remains relevant given the burden of dementia and osteoporosis in our ageing population. Future research into amyloid beta, APOE4 and vitamins K and D as the most promising aetiological links should be welcomed.

Open versus laparoscopic right hemicolectomy in the elderly population

AIM:To compare short term outcomes of elective laparoscopic and open right hemicolectomy(RH) in an elderly population.METHODS:All patients over the age of 70 undergoing elective RH at Ninewells Hospital and Perth Royal Infirmary between January 2006 and May 2011 were included in our analysis.Operative details,hospital length of stay,morbidity and mortality was collected by way of proforma from a dedicated prospective database.An extracorporeal anastomosis was performed routinely in the laparoscopic group.The primary endpoints for analysis were morbidity and mortality.Our secondary endpoints were operative duration,length of hospital stay and discharge destination.RESULTS:Two hundred and six patients were included in our analysis.One hundred and twenty-five patients underwent an open resection and 81 patients had a laparoscopic resection.The mean operating time was significantly longer in the laparoscopic group(139 ± 36 min vs 197 ± 53 min,P = 0.001).The mean length of hospital stay was similar in both groups(11.2 ± 7.8 d vs 9.6 ± 10.7 d,P = 0.28).The incidence of postoperative morbidities was 27% in the open group and 38% in the laparoscopic group(P = 0.12).Overall inhospital mortality was 0.8% in open procedures vs 1% in laparoscopic.CONCLUSION:Laparoscopic RH was associated with a significantly longer operative time compared to open RH.In our study,laparoscopic RH was not associated with reduced post-operative morbidity or significantly shorter length of hospital stay.

Peri-Operative Hearing Impairment

Peri-operative hearing impairment is a poorly reported morbidity following any type of anaesthesia. We report a case where the patient developed temporary hearing impairment after a gynaecological surgery. This recovered in a couple of week time. The causes of such hearing impairment in various types of anaesthesia are discussed.

人神经生长因子β基因转染对糖尿病大鼠神经病理性痛的影响

目的 探讨皮下转染重组腺病毒介导的人神经生长因子β（Ad-hNGFβ）基因对糖尿病大鼠神经病理性痛的影响及其可能机制。方法 采用腹腔注射佐脲霉菌素（STZ）75mg／kg的方法制备大鼠糖尿病模型。健康雄性SD大鼠，体重180～220g，随机取10只大鼠作为对照组（C组）不制备糖尿病模型；取模型制备成功的大鼠75只随机分为3组（n=25）：糖尿病神经病理性痛组（DNP组）、Ad-hNGFβ基因治疗组（NGF组）和Ad-LacZ基因治疗组（LacZ组）。NGF组和LacZ组分别于STZ注射后21d且痛阈测定结束后双侧腹股沟皮下脂肪接种1．12×10^11 PFU Ad-hNGFβ10μl和1．12×10^11 PFU Ad-LacZ 10 μl，C组和DNP组不作任何处理。于STZ注射前（基础状态）、注射后21、35、49d时测定机械痛闯和热痛阈。于注射后49d且痛阈测定结束后测定血清hNGF／3浓度和背根神经节降钙素基因相关肽（CGRP）的表达。结果与基础值和C组比较，DNP组、NGF组和LacZ组STZ注射后机械痛阈和热痛阈均降低，DNP组和LacZ组血清hNGFβ浓度和背根神经节CGRP表达下降，NGF组血清hNGFβ浓度和背根神经节CGRP表达升高（P〈0．05）；与DPN组比较，NGF组STZ注射后49d时热痛阈升高，血清hNGF／3浓度和背根神经节CGRP表达升高（P〈0．01），LacZ组各项指标差异无统计学意义（P〉0．05）。结论 Ad—hNG耶基因转染可在一定程度上减轻糖尿病大鼠神经病理性痛，其机制与上调背根神经节CGRP表达有关。

Robot-assisted single lung transplantation

To the Editor:Currently,lung transplantations are typically performed via a transverse thoracosternotomy or a sternotomy for double lung transplantation,or a posteriolateral thoracosternotomy for single lung transplantation.However,these extremely invasive approaches may contribute to early post-operative pain,delay wound healing,and cause chronic post-thoracotomy neuralgia,which can affect patient’s quality of life.[1,2]Of interest,several minimally invasive surgical methods for lung transplantation were reported.[3,4]Furthermore,robotic surgical systems are now widely used in the field of thoracic surgery.Herein,we reported a case of performing robot-assisted right single lung transplantation for a patient with end-stage chronic obstructive pulmonary disease(COPD).

异氟醚麻醉期间低碳酸血症和脑自主调节功能对脑血管阻力和表观零流压的影响

背景同步监测动脉血压（arterial blood pressure，ABP）和大脑中动脉血流速度可用于计算表观零流压（apparent zero flow pressure，aZFP）。压力一流速关系斜率的倒数被称为阻力面积乘积（resistance area product，RAP），是一项脑血管阻力指标。关于血管活性药物，动脉血二氧化碳分压（PaCO，）和脑自动调节功能受损在全身麻醉时对aZFP和RAP影响的研究很少。我们研究了异氟醚麻醉期间低碳酸血症和输注去氧肾上腺素对aZFP和RAP的影响。方法记录11名成年受试者在异氟醚麻醉期间桡动脉有创ABP和经颅多普勒所测的大脑中动脉血流速度信号。输注去氧肾上腺素增加ABP，调整通气以控制PaCO2。分别在两个不同的平均ABP水平（大约在80mmHg和100mmHg）和PaCO2水平（正常PaCO2：38～43mmHg和低碳酸水平：27～34mmHg），比较脑血流动力学的变化。对两种aZFP分析方法进行比较：一种基于线性回归，一种基于波形的傅立叶分析。结果在较低ABP水平，血碳酸正常时，aZFP为23±11mmHg，RAP为0．76±0．97mmHg·s·cm^-1；低碳酸血症时，aZFP为30±13mmHg（均数±标准差），RAP为1．16±0．16mmHg·s·cm^-1。，P〈0．001。在较高ABP水平可见到低碳酸血症带来的类似效应。血碳酸水平正常时，异氟醚对脑自主调节功能的损害及aZFP的影响不随ABP的上升而改变。低碳酸血症时，脑血管自动调节功能无明显损害，ABP的升高会使aZFP增加（从30±13mmHg增加到35±13mmHg，P〈0．01）和RAP增加（从1．16±0．16mmHg增加到1．52±0．20mmHg·S·cm^-1，P〈0．001）。评估aZFP和RAP对脑血流动力学的相对作用显示，RAP的变化显然比aZFP的变化在其中起更重要的作用。两种分析aZFP的方法（傅里叶分析法一线性回归法）的平均差为0．5±3．6mmHg（均数±2标准差）。结论异氟醚麻醉期间，低碳酸血症和大脑对ABP升高的自主调节反应，这两个因素可增加大脑小动脉张力，与RAP和aZFP的升高相关。RAP的变化显然比aZFP的变化产生更大的影响。这些结果提示小动脉张力通过控制血管阻力和有效灌注压来影响脑血流。

增加清醒下颈动脉手术患者氧供可改善脑氧合

背景颈动脉内膜剥脱术（CEA）区域麻醉期间，动脉夹闭后，根据语言、思维、对侧运动肌力的改变可发现10％～15％的患者会出现脑缺氧征象。使用100％氧供以逆转这一现象的研究已有报道。我们使用了近红外脑血氧饱和度监测以评估吸入100％氧是否确能提高颈动脉夹闭期间的局部脑氧舍（rSO2）。方法16例清醒CEA手术患者，开始镇静和实施区域麻醉前放置双侧rSO2电极，通过Venturi面罩给予28％氧吸入，颈动脉夹闭期间维持动脉血压于正常范围或高于正常值10％以内。动脉夹闭后使用紧闭麻醉面罩给予100％氧吸入5分钟，随后去除面罩吸入室内空气，监测对各阶段rSO2数据和动脉血气的影响。结果分析15例患者数据，颈动脉夹闭后同侧rSO2值下降7．4％±5％，与吸入28％氧者相比，吸入100％氧后同侧rSO2升高了6．9％±3．3％（范围1％～12％）（配对t检验，P〈0．001）。血流动力学指标和二氧化碳分压没有改变。结论颈动脉夹闭时，相对于28％的氧，100％氧能有效地提高同侧rSO2值。确切的机制尚不清楚，可能与血氧含量及脑血流增加有关。对于CEA患者，颈动脉夹闭期间给予100％氧供会有益处。

意料中的意外结果

右美托咪啶是一种高选择性的仅，一肾上腺受体激动剂，对它的3个亚型有相同的亲和力。在d，一肾上腺受体介导的众多生理反应中，镇静、抗交感和镇痛作用是经常接受右美托咪啶治疗的100万患者所希望达到的。健康志愿者能忍受比临床治疗浓度高15—20倍的右美托咪啶表明该药相对安全，且治疗窗较宽。继上次在本刊的一篇相似报道之后，Sichrovsky等人在本期的《麻醉与镇痛》里介绍了1例与使用右美托咪啶有关的导致心血管系统相关的死亡病例。用药前这2例患者心脏传导功能均有异常。右美托咪啶之所以被认为有很好的心血管作用，在很大程度上是因为它的中枢抗交感作用和外周血管收缩作用结合在一起。在健康志愿者中，这些心血管作用是呈剂量相关的，而且具有高度的可预见性。然而，生理学上的“健康”并不是取决于交感神经状态或者能接受抗交感作用而无后遗症。

转化型研究：着重解决麻醉医生面临的问题

目前，转化型研究（translational research）已成为医学研究理念的基石，通过实验室和临床工作者相互合作可以促进医学的重大发展。尽管目前为手术提供的麻醉监护是相当安全的，但在依然具有风险的围手术期，要取得专业上的新进展就需要建立转化型研究以解决临床问题。临床研究的合理设计依赖于良好的、大量可重复的临床前数据来支持进行前瞻性临床研究的大规模投入，而只有大规模的前瞻性研究结果才具有足够的研究效力以指导改变临床实践的实施。

B-Aware研究中术中知晓患者的创伤后应激障碍

背景术中知晓的长期影响差异巨大，部分患者没有任何长期影响，而另一些患者则可导致严重和持久的心理障碍。本研究比较了随机化B—Aware研究中，发生明确术中知晓患者与未发生明确术中知晓患者创伤后应激障碍（postlraumaticstressdisorder，PTSD）的发生率。方法我们采用配对群体设计，旨在随访发生明确术中知晓的13例患者。每1例发生术中知晓的患者均按年龄、性别、手术类型、手术日期及手术医院配比4例对照。以临床术后应激障碍评分对每1例术中知晓及对照患者进行面对面的访谈。结果本研究收集数据资料的时间从2006年6月到2007年3月，随访的中位数时间5．3年（范围4．3-5．7年）。其间发生明确术中知晓的13例患者中6例去世，7例患者中的5例（71％）与25例对照中的3例（12％）在随访时点表现符合PTSD的诊断标准（校正的比值比=13．3[95％的可信区间为1．4-650]，P=0．02）。症状出现时间中位数时间为术后14天（范围7-243天），症状持续时间的中位数为4．7年（范围4．4-5．6年）。结论PTSD在B-Aware研究中有明确术中知晓的患者中常见而且持久。全麻下应强化预防患者术中知晓的措施。