比较脑电非线性指数与BIS在丙泊酚靶控输注时预测镇静深度的临床研究

目的:本研究旨在比较一种新的脑电参数-脑电非线性指数(ENI)与BIS在丙泊酚靶控输注时预测镇静深度的能力。方法:选择30例18～60岁,ASAⅠ～Ⅱ级,拟行择期普外科手术患者。每一患者同时监测ENI和BIS。麻醉诱导给予丙泊酚靶控输注,直至患者意识消失后给予芬太尼和罗库溴铵行气管插管。麻醉诱导过程中每30秒进行一次镇静评分(采用改良OAA/S评分),并记录ENI和BIS值以及平均动脉压(MAP)和心率(HR)。结果:ENI和BIS与镇静评分的相关性比MAP和HR高(r=0.90、0.93vsr=0.77、0.27)。镇静过程(改良OAA/S评分)中ENI和BIS有很好的相关性(R2=0.828)。ENI和BIS预测镇静深度的能力优于MAP和HR。结论:ENI可提供与BIS相似的反映镇静深度的信息,能准确预测不同的镇静深度。     

异丙酚靶控镇静40例分析

目的：观察异丙酚患者靶控镇静术（TCI）在硬膜外阻滞中的应用价值。方法：40例行下肢手术的成年患者,硬膜外麻醉满意后,开始行靶控输注,术中维持镇静深度于OAA/S镇静评分3分。监测不同时点的镇静评分、双频谱指数（BIS）、边缘频率（95%SEF）、并比较BIS、95%SEF与镇静评分的相关性。结果：所有患者均对镇静效果满意,异丙酚平均用药量为3.5 mg/（kg.h）。BIS与镇静评分的相关性（r=0.73）较95%SEF高。结论：靶控镇静效果满意,镇静的深度平稳且易于调控。BIS是监测部位麻醉中镇静深度的较敏感指标。     

靶控输注咪达唑仑用于老年结直肠癌根治术的镇静安全性评价

目的评价靶控输注咪达唑仑用于老年结直肠癌(CRC)患者术中镇静的安全性。方法将50例老年CRC患者随机分为观察组及对照组各25例, 分别给予TCI咪达唑仑及异丙酚组, 利用警觉镇静评分(OAA/S)和脑电双频指数(BIS))监测镇静程度, 记录不同OAA/S评分下的平均动脉压(MAP)、心率(HR)、脉搏血氧饱和度(SpO₂)、BIS及血药浓度, 并监测不良反应及记录苏醒时间。结果当OAA/S=2分时, 观察组的BIS、MAP及HR均明显高于对照组(P < 0.05), 但观察组均在正常范围; OAA/S=2分时观察组的血药浓度同样高于对照组(P < 0.05);重复测量方差分析显示观察组以上3项指标随OAA/S评分变化的波动较小。观察组的苏醒时间与对照组差异无显著性(t=0.086, P=0.209);两组的呼吸抑制、低氧血症、低血压及躁动的例数构成差异无统计学意义。结论靶控输注咪达唑仑对老年CRC患者的血压及心率波动较小, 因此其安全性较异丙酚理想。      

老年人脑电双频指数、异丙酚血药浓度与镇静深度的相关性

目的：探讨老年手术患者椎管内麻醉后应用异丙酚镇静,脑电双频指数、异丙酚血药浓度和镇静深度之间的相关性。方法：48例ASAⅠ-Ⅱ级择期手术患者,分为老年组（65-85岁）和年轻组（18-40岁）,每组24例。为尽快达到稳态血药浓度,采用靶控输注方式给药。异丙酚靶浓度从0.5μg/mL起逐渐增加,直至患者对轻推无反应（意识消失）,每个浓度维持5min。连续记录EEG参数,在每一稳态血药浓度末,记录BIS、95%SEF,桡动脉取血（高效液相色谱法测定异丙酚血药浓度）,并评定镇静深度（OAA/S评分法）。用Spearman’s等级相关进行相关分析,并计算预测概率（Pk）值。结果：两组BIS（r=0.935-0.955）与镇静水平的相关性优于血药浓度（r=-0.849-0.870）和95%SEF（r=0.503-0.571）,BIS的Pk值高（0.942-0.972）。在同一镇静评分（OAA/S 41）时,老年组BIS值明显高于年轻组（P〈0.01）,而血药浓度低于年轻组（P〉0.05）。结论：BIS在监测异丙酚镇静水平及预测意识消失方面有重要价值,在同一镇静评分时,老年人BIS值高于年轻人。     

靶控输注依托咪酯用于老年患者硬膜外麻醉清醒镇静的疗效

目的：观察依托咪酯用于老年患者硬膜外麻醉静脉靶控输注清醒镇静的可行性。方法：60例行硬膜外麻醉老年患者,分别予以依托咪酯（E组）和丙泊酚（P组）靶控输注,记录OAA／S评分为3分时两组的MAP、SpO2、HR值及0AA／s评分为5～1分时的CSI值。结果：P组患者出现MAP、SpO2、HR下降的例数多于E组,两组的OAA／S评分与CSI值呈正相关。结论：CSI值指导靶控输注依托咪酯可用于老年患者硬膜外麻醉清醒镇静。     

脑电双频指数监测在机械通气患者镇静中的应用

目的探讨脑电双频指数(bispectral ral index,BIS)监测在重症医学科机械通气患者镇静中的应用现况。方法纳入需镇静治疗的ICU机械通气患者25例,根据病情采用靶控输注镇静药物,同时进行BIS监测和Ramsay评分,监测心率(heart rate,HR)、呼吸频率(breathing rate,RR)、平均动脉压(mean arterial pressure,MAP)、外周血氧饱和度(Sp O2)。结果随着镇静程度的加深,Ramsay评分逐渐增高,而BIS逐渐下降(P<0.05)。BIS数值约60~80的生命体征较镇静前平稳,HR、RR、MAP在镇静后数值均较镇静前下降(P<0.05);Sp O2镇静前后比较差异无统计学意义(P>0.05)。结论 BIS不仅能准确反映镇静深度,并可动态量化监测镇静深度,减少护理量及不良事件发生,可用于ICU镇静深度的监测。     

甲状腺手术局部麻醉期间应用力月西靶控镇静的疗效分析

目的：观察力月西靶控输注及伍用芬太尼时的镇静效果。方法：选择90例甲状腺手术局部麻醉患者,随机分为力月西静脉注射组（L组）、力月西靶控组（B组）、力月西靶控伍用芬太尼组（F组）,比较3组疗效。结果：三组力月西用量、镇静时间、苏醒时间差异有统计学意义（P〈0.01） 随镇静程度加深,三组MAP、HR、SpO2、RR发生相应的改变 B、F组AEPI与OAA/S呈正相关,目标血药浓度、效应室浓度与OAA/S呈负相关。结论：在镇静起效期及恢复期间的AEPI与OAA/S评分相关性最好。     

异丙酚靶控输注联合脑电双频指数反馈控制应用于老年人无痛肠镜检查的临床观察

目的研究异丙酚靶控输注联合脑电双频指数反馈控制应用于老年人无痛肠镜检查的临床效果。方法选择50例ASAI、II级,60～80岁择期行全身麻醉下结肠镜检查病人,分为两组,每组25例。人工(MCI)组开始通过输液泵以7200mg/h输注速度给予单剂量异丙酚直至患者意识消失,随即按4mg/(kg·h)持续给药。靶控输注联合脑电双频指数反馈控制(TCI联合BIS)组将病人年龄、体重及靶浓度(CT)3.6μg/mL输入注射泵,由其控制持续输注异丙酚,并根据BIS值进行反馈调节。观察记录诱导和苏醒时间、麻醉效果、异丙酚总量,无创监测术前、术中的心率(HR)、平均动脉压(MAP)、血氧饱和度(SpO2)及BIS值下降情况。结果与人工组相比,TCI联合BIS组麻醉诱导时间延长,异丙酚用量减少,两组病人术中MAP、HR较术前均下降,但TCI联合BIS组最大降幅明显小于人工组。结论异丙酚靶控输注联合脑电双频指数反馈控制应用于老年人肠镜检查,是安全、有效的,且老年受检者的血流动力学及呼吸功能更加稳定,该麻醉方法值得进一步研究推广。     

靶控输注不同浓度瑞芬太尼对脑电双频指数的影响

目的通过靶控输注不同浓度瑞芬太尼，研究其对脑电双频指数（BIS）的影响。方法美国麻醉学会手术前分级标准原则（ASA）Ⅰ～Ⅱ级择期全麻手术患者60例，随机分为3组（n=20）。瑞芬太尼靶控输注（TCI）靶浓度2．0ng／ml（Ⅰ组），4．0ng／ml（Ⅰ组），6，0ng／ml（Ⅲ组），记录给药前和达到预设效应室浓度1min后的心率（HR），平均动脉压（MAP），氧饱和度（SpO2），BIS和镇静警醒（OAA／S）评分。结果与给药前相比，靶控输注瑞芬太尼后，Ⅱ组Ⅲ组BIS降低明显（P〈0．05或P〈0.01），Ⅲ组OAA／S评分降低明显（P〈0，05）。与Ⅰ组相比较，Ⅱ组的BIS值降低有显著性差异（P〈0，05），Ⅲ组BIS值和OAA／S评分降低均有显著性差异（P〈0.05）。结论 瑞芬太尼靶浓度与BIS值呈负相关性，与OAA／S评分相比，BIS监测瑞芬太尼镇静效果更敏感与准确。     

靶控输注异丙酚术中镇静的药效学研究

目的：确定不同异丙酚药代学参数的靶控输注（TCI）系统用于硬膜外麻醉的药效学。方法：27例ASAⅠ～Ⅱ级择期硬膜外麻醉手术患者，术中分别采用Tachely（T组）和Shafer（S组）报告的异丙酚药代学参数TCI系统靶控输注镇静，靶浓度从0．4μg／ml开始，以0．4μg／ml梯度逐渐上升，直至患者入睡，每个靶控浓度至少维持15min以上。记录平均动脉压（MAP）、心率（HR）、脉搏氧饱和度（SpO2）和镇静警醒（OAA／S）评分。结果：T组和S组50％患者的意识消失浓度分别是1．1μg／ml和1．4μg／ml。MAP随靶控浓度的升高而降低，T组和S组MAP最大降低幅度分别为19％和21％。结论：硬膜外麻醉下靶控输注异丙酚镇静，可控性强，维持血液动力学稳定，但不同药代学参数TCI系统的临床应用各有特点。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.