急性高容量血液稀释复合控制性降压在围术期血液保护中的临床应用

【目的】观察琥珀酰明胶急性高容量血液稀释（AHH）复合瑞芬太尼控制性降压在围术期血液保护中的作用。[方法]40例ASAI-Ⅱ级拟行择期手术（出血量估计大于血容量的15％）的病人,随机分为观察组（I组）和对照组（Ⅱ组）,每组20例。均采用全麻,I组于切皮前行AHH,按15mL／kg、50mL／min输入琥珀酰明胶。AHH开始后持续泵入瑞芬太尼0．05-2μg／（kg·min）行控制性降压。Ⅱ组常规输液。记录气管插管后或AHH前（T1）、AHH结束即刻或手术开始时（T2）、AHH后或手术开始后60min（T3）、术毕（T4）的动脉凝血指标、乳酸浓度及术中出血量和输血量。【结果】I组病人失血量、输血量和输血例数明显少于Ⅱ组（P〈0．05）;两组T2-T4时凝血酶原时间（PT）和凝血活酶时间（APTT）较T1时均有所延长,但差异无统计学意义,各时点的两组间的差异亦无统计学意义;I组T2-T4时红细胞比客（Hct）较T1时下降（P〈O．05）,T3、T4时Hct下降幅度I组大于Ⅱ组（P〈0．05）;两组动脉血乳酸浓度无明显变化。【结论】琥珀酰明胶AHH复合瑞芬太尼控制性降压用于失血量大的手术病人可以减少术中出血量,减少输血,不影响凝血功能和组织器官氧供,可安全用于围术期血液保护。     

术前急性高容血液稀释对围术期控制性降压内环境的影响

目的 :探讨术前急性高容血液稀释对围术期控制性降压期间内环境的影响。方法 :将 3 0例脊柱外科手术病人随机分为两组 ,术前急性高容血液稀释联合术中控制性降压组 (联合组 )和单纯的控制性降压组 (对照组 ) ,观察联合组插管后稀释前 (T0 )、稀释后降压前 (T1)、降压后 3 0min(T2 )和停降压后 3 0min(T3 ) 4个时间点 ,对照组插管后降压前 (T1)、降压后 3 0min(T2 )和停降压后 3 0min(T3 ) 3个时间点动脉血的血气分析、钾离子 (K+ )、钠离子 (Na+ )、钙离子 (Ca2 + )和氯离子 (Cl-)浓度变化。结果 :pH值联合组T1、T2 、T3 较T0 降低 (P <0 0 1) ,T1、T2 和T3之间无明显改变 (P >0 0 5 )。两组血K+ 、Na+ 、、Ca2 + 和Cl-的变化无统计学意义。结论 :术前急性高容血液稀释对围术期控制性降压期间的内环境无明显影响     

瑞芬太尼丙泊酚复合麻醉兼控制性降压联合血液稀释在椎弓根固定术的临床应用

目的：探讨瑞芬太尼、丙泊酚复合麻醉兼控制性降压,联合血液稀释在椎弓根内固定术应用的安全性、有效性。方法：选择择期胸、腰椎手术患者30例,性别不限,ASAⅠ～Ⅱ级,年龄22～54岁,体重50-70kg。随机分为3组,每组10例,对照组（C组）,不施行控制性降压和血液稀释,R组行瑞芬太尼丙泊酚控制性降压联合血液稀释,P组血液稀释。控制性降压丙泊酚4～6mg·kg^-1·h^-1瑞芬太尼初始速率为0．25μg·kg^-1·min^-1,每2min增加或减少0．1μg／kg直至降至靶目标血压,维持MAP为基础值65％～75％,以MAP≥65mmHg（1mmHg=0．133kPa）至椎弓根内固定结束。血液稀释输入羟乙基淀粉130／0．4氯化钠注射液（HS）10mL／kg,输入速率30mL／min．分别于施麻前（T0）、麻醉后30min（T1）、60min（T2）、90min（T3）、手术结束（T4）记录各项监测指标。结果：P组和R组与T0时比较T1-4时血细胞比容（Hct）降低（P〈0．05）,C组与T0时比较T3～4时Hct降低（P〈0．05）,与C组比较P组和R组T1-2时Hct降低（P〈0．05）。P组与R组差异无统计学意义（P〉0．05）;R组HR与T0比较T1-3均减慢（P〈0．05）,与C组比较T1～3均减慢（P〈0．05）,CVP、P组T1～3均高于R组和C组（P〈0．05）,MAP、R组与T0比T1-3均降低（P〈0．05）,与C组比T1～3均降低（P〈0．05）。R组出血量和异体输血量均少于P组和C组（P〈0．05）。结论：瑞芬太尼、丙泊酚复合麻醉兼控制性降压联合血液稀释在椎弓根内固定术中应用安全、有效。     

控制性降压和血液稀释联合应用对大脑中动脉流速的影响

目的:探讨控制性降压和血液稀释联合应用对大脑中动脉流速(Vmca)的影响.方法:ASA Ⅰ～Ⅱ神经外科患者30例,芬太尼-丙泊酚-维库溴铵诱导后随机均分两组,用130/0.4羟乙基淀粉进行急性等量血液稀释至红细胞压积A组为32%,B组为24%.术中硝普钠行控制性降压至平均动脉压55 mmHg 80 min.测量血液稀释前后、控制性降压后80 min及控制性降压结束后60 min的Vmca及血气分析.结果:血液稀释后(T1)Vmca A组(+126%)、B组 (+158%)均较血液稀释前(T0)显著增加;与血液稀释前(T0)比,B组控制性降压后80 min(T2) (+132%)控制性降压结束后60 min(T3) (+138%)Vmca均显著增加.A组 Vmca T2、T3时较T1时明显增加(P ＜ 0.05),T1时B组较组A明显增加(P ＜ 0.05),但T2或T3点两组Vmca差异无显著性(P ＞ 0.05).B组 T1时搏动指数明显增加(P ＜ 0.05),但T2时较T1时差异无显著性(P ＞ 0.05).结论:全麻中等血液稀释红细胞压积(24%)时硝普钠并不减少大脑中动脉流速.     

瑞芬复合七氟烷控制性降压联合急性高容量血液稀释在髋部手术中的应用

目的探讨瑞芬太尼复合七氟烷控制性降压（CH）联合6％羟乙基淀粉急性高容量血液稀释（AHH）在髋部手术中的血液保护作用和安全性。方法选择ASAⅠ、Ⅱ级的髋部手术患者40例,除外贫血、心肝肾功能不全、严重高血压、凝血功能障碍以及肥胖患者。随机分为观察组和C对照组,每组20例,全麻诱导后即行AHH,30min内输入6％羟乙基淀粉130／0．4约15mL／kg。手术开始进人骨质操作后行CH,观察组通过泵注瑞芬太尼及吸人七氟烷,对照组通过泵注硝酸甘油维持MAP于65～70mmHg直至手术骨质操作完成。分别测定并记录AHH前、AHH后、CH前、停CH即刻、手术结束时的MAP、中心静脉压（cvP）、凝血酶原时间（PT）、活化部分凝血酶原时间（ARTT）、Hb、HCT、血小板计数（PLT）等。记录术中平均出血量、平均输血量、输血例数、尿量、清醒拔管时间及术后24h引流量。结果两组患者AⅢ后、CH前、停止CH即刻及手术结束时的ARTT和PT与AHH前比较无差异（P〉0．05）;CH期间观察组的心率（HR）显著低于降压前（P〈0．05）,而对照组高于降压前（P〈0．05）,对照组CVP显著低于降压前（P〈0．05）,观察组与降压前相比无差异（P〉0．05）;观察组失血量明显少于对照组（P〈0．05）,两组患者术后24h引流量、清醒拔管时间等比较无差异（P〉0．05）。结论瑞芬太尼复合七氟烷控制性降压联合6％羟乙基淀粉急性高容量血液稀释用于髋部手术中安全有效,且与传统药物硝酸甘油相比,瑞芬太尼复合七氟烷控制性降压具有减慢心率、降压平稳、对中心静脉压影响小、失血量少等优点。     

急性高容量血液稀释联合控制性降压减少脑膜瘤手术出血量的临床研究

【目的】探讨应用急性高容量血液稀释联合控制性降压减少脑膜瘤围手术期出血量的效果。【方法】45例择期脑膜瘤手术患者随机分为3组,每组15例。急性高容量血液稀释联合控制性降压组(联合组):术前输入6%羟乙基淀粉20ml/kg和乳酸林格氏液20ml/kg行急性高容量血液稀释;术中微量泵输注硝普钠0.4～6μg/(kg·min)实施控制性降压,血压较基础血压下降20%～25%。单纯控制降压组(降压组)术中控制性降压同联合组。对照组按常规处理。术毕测定出血量和实际出血量,记录手术时间和输血量。【结果】联合组与降压组出血量、输血量、实际失血量、手术时间均较对照组明显下降(P<0.05)。联合组实际出血量明显少于降压组(P<0.05)。【结论】术前急性高容量血液稀释联合术中控制性降压可以明显减少脑膜瘤手术时的出血量,输血量明显下降,提高节约用血效果。     

控制性低中心静脉压对老年肝切除手术患者内脏灌注的影响

目的：观察控制性低中心静脉压（LCVP）对老年肝切除手术患者内脏灌注的影响。方法择期行肝切除术的原发性肝癌老年患者40例,随机分为LCVP组和对照组,每组20例,LCVP组限制输液,开腹后静脉泵注硝酸甘油0.02～0.2μg·kg-1·min-1,必要时适当增加异氟醚吸入浓度,维持中心静脉压（CVP）2～5 cmH2O至肝实质完全离断,肝实质离断后停止输注硝酸甘油,快速输注6％羟乙基淀粉将CVP恢复至正常范围。对照组常规处理。观察CVP降低前（T0）、CVP降低后30 min（T1）、60 min（T2）及术毕（T3）各时点的CVP、平均动脉压（MAP）、心率（HR）、心输出量（CO）、动脉血二氧化碳分压（PaCO2）和动脉血pH值（pHa）,及各时点胃黏膜二氧化碳分压（PgCO2）和胃黏膜pH值（pHi）。结果 LCVP组在T1和T2时与T0时点比较, CVP和MAP降低,HR和CO增高,差异均有统计学意义（q分别=12.65、8.45、4.28、3.19、10.71、9.34、3.81、3.41,P均＜0.05）;LCVP组在T1和T2时与对照组比较,CVP和MAP降低,HR和CO增高,差异均有统计学意义（t分别=8.81、6.62、1.91、2.21、12.76、4.16、1.71、2.45,P均＜0.05）。两组间同时点Pa-CO2、PgCO2、pHa及pHi比较比较,差异均无统计学意义（t分别=1.75、0.82、0.00、0.00,P均＞0.05）;LCVP组各指标T1、T2和T3时与T0时点比较,差异均无统计学意义（t分别=1.64、0.10、1.58、1.58、0.68、0.33、0.89、1.24、0.79、0.88、1.24、1.58,P均＞0.05）。结论 LCVP 期间维持CVP 2～5 cmH2O,持续时间在2 h以内对老年肝切除手术患者内脏灌注无明显不利影响。     

急性高容量血液稀释对老年手术患者凝血及肾功能影响

目的：观察围术期急性高容量血液稀释（AHH）对老年患者凝血功能、肾功能的影响。方法：30例60岁以上择期手术患者随机分为3组。A、B组分别用HES、LR液行AHH，C组不行AHH。于AHH前（T1）、AHH毕（T2）、AHH后60mln（T3）、术毕（T4）及术后第1天晨（T5）测定：PT、APTT、FIB、BUN、CR及尿NAG酶。记录术中、术后出血量和输血量。结果：3组PT无明显变化（P〉0．05），A组APTT在T2、T3点较T1点延长（P〈0．05），3组FIB在T5点高于同组T1点（P〈0．05），各凝血功能指标组间比较差异无显著性。BUN、CR各时点均在正常范围内，尿NAG酶在T3～T5点均高于T1点（P〈0．05），组间比较差异无显著性。术中、术后输异体血量C组例数明显多于A、B组。（P〈0．05）。结论：用6％HES行AHH对老年患者凝血功能、肾功能无明显影响，同时可减少术中、术后异体血输注。     

急性等容血液稀释联合术中控制性降压在外科大手术中的应用

目的探讨急性等容血液稀释（acute normovolemic hemodilution,ANH）联合术中控制性降压（deliberatehypotension,DH）用于外科大手术的临床效果。方法将75例择期行外科大手术患者按随机数字表法分为联合组、降压组和对照组,每组25例。联合组采取ANH联合术中DH措施,降压组采取术中DH措施,对照组按常规处理。观察3组患者动、静脉穿刺置管完成后T0（基础值）、T1（ANH后）、T2（术毕即刻）和T3（术后24h）的血红蛋白（Hb）、红细胞压积（Hct）、血小板计数（PLT）水平的变化情况,手术时间和术中失血量、异体输血量、尿量及输血等情况。结果联合组T2PLT、Hb水平均明显高于降压组和对照组（P〈0.05或P〈0.01）,联合组T0、T1Hb、Hct、PLT水平与降压组、对照组比较差异均无统计学意义（均P〉0.05）,联合组、降压组手术时间均明显短于对照组（P〈0.05或P〈0.01）;联合组术中失血量、异体输血量和输血率均明显低于降压组和对照组（P〈0.05或P〈0.01）,降压组术中失血量、异体输血量和输血率均明显低于对照组（P〈0.05或P〈0.01）,联合组尿量多于降压组和对照组（P〈0.05）,降压组尿量与对照组比较差异无统计学意义（P〉0.05）。结论 ANH与DH联合用于外科大手术可显著减少出血量,不输或少输异体血,不失为围术期血液保护的有效措施。     

术前应用6%羟乙基淀粉行急性高容量血液稀释对老年患者动脉压及氧代谢的影响

目的：探讨应用6％羟乙基淀粉行急性高容量血液稀释（AHH）对老年患者动脉压和氧代谢的影响。方法：随机选择腹部择期手术的老年患者40例,随机分为两组,A组为高容量血液稀释组,B组为非血液稀释组。B组入室后补充基础生理需要量及禁食丧失需要量。A组患者以25ml／min的速率输入6％羟乙基淀粉7ml／kg后诱导,同时继续输入达15ml／kg行高容量血液稀释,分别监测记录基础值（T0）、诱导后插管前（T1）、插管后即刻（T2）、插管后5min（T3）、10min（T4）、20min（T5）、切皮前（L6）的平均动脉压（MAP）、心率（HR）、中心静脉压（CVP）。经桡动脉取血测血气、Lac。结果：A组患者诱导前后MAP无显著性差异（P〉0．05）,B组诱导后MAP显著降低（P〈0．05）。与同时相A组比较有显著性差异（P〈0．05）。A组CVP插管后5min（T3）与基础值（T0）比较有显著性差异（P〈0．05）。与同时相B组比较有显著性差异（P〈0．05）,两组患者HR诱导后减慢（P〈0．05）。A组血红蛋白（Hb）、细胞压积（Hct）在血液稀释后显著降低（P〈0．05）。两组血气、Lac在血液稀释前后无显著性变化（P〉0．05）。结论：适度AHH有利于维持老年患者血液动力学的稳定,而氧代谢改变不明显,值得临床推广。     

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.