脓毒性休克早期液体复苏对血管外肺水的影响及相关因素研究

目的探讨脓毒性休克早期液体复苏对血管外肺水（EVLW）的影响及相关因素研究。方法选择20例脓毒性休克早期存在血容量不足[即胸内血容量指数（ITBVI）〈750ml／m^2]的患者，给予血定安快速液体复苏至ITBVI〉850ml／m^2为复苏终点，采用单指示剂热稀释法测定的血管外肺水指数（EVLWI），根据入选时EVLWI监测值将患者分为EVLWI≤7ml／kg（n=8）及EVLWI〉7ml／kg（n=12）两组，监测液体复苏前（Tb）及复苏结束后即刻（T0）、1h（T1）、2h（T2）、4h（T4）血流动力学、EVLWI、氧合指数（PaO2／FiO2）等指标的变化。结果①两组患者在达到液体复苏终点后T0、T1、T2时ITBVI、全心舒张末期容积指数（GEDVI）、心排血指数（CI）、每搏指数（SI）、中心静脉压（CVP）均明显增高（P〈0.05或P〈0.01），但T4与Tb相比差异均无显著性（P均〉0．05）；两组同时间点ITBVI、GEDVI、CI、SI、CVP比较差异均无显著性（P均〉0．05）。②与Tb相比，两组在T0、T1、T2、T4时EVLWI、PaO2／FiO2均无明显改变（P均〉0．05），但EVLWI〉7ml／kg组在各相同时间点PaO2／FiO2均显著低于EVLWI≤7ml／kg组（P均〈0．05）；③在早期复苏过程中EVLWI与ITBVI、GEDVI、CI、SI、CVP均无明显相关性（P均〉0．05），与PaO2／FiO2具有负相关性（r=-0．765，P〈0．01），与肺毛细血管渗透性指数（PVPI）呈正相关（r=0．678，P〈0．01）；④20例患者中28d内死亡6例（占30％），死亡患者复苏前后EVLWI均显著高于存活患者（P均〈0．05），但复苏前后EVLWI变化值（△EVLWI）比较差异无显著性（P〉0．05）。结论脓毒性休克早期进行液体复苏可使ITBVI、GEDVI、CI、SI、CVP增加，但不影响EVLW及氧合。EVLWI的升高可能与PVPI增加有关，与PaO2／FiO2呈负相关，并与患者预后密切相关。     

32例脓毒性休克患者动脉轮廓法血流动力学监测变化特点分析

目的 观察脓毒性休克患者在早期目标治疗(EGDT)前后动脉轮廓法(PiCCO)血流动力学监测的变化特点.方法 32例脓毒性休克患者分为存活组(n=23)及死亡组(n=9).同期类似病种无休克患者为对照组(n=5).于诊断即刻、6 h、12 h和24 h监测心率(HR)、血压(BP)、尿量(UV)和中心静脉压(CVP);同时利用PiCCO监测仪测定平均动脉压(MAP)、心排量(CO)、全心舒张末期容量指数(GEDVI)、体循环阻力指数(SVRI)、血管外肺水指数(EVLWI)和肺血管通透指数(PVPI).结果 脓毒性休克患者入院初始GEDVI、MAP较对照组显著降低,HR明显增快,尿量减少(P<0.01);18例 CO≥7.0 L/min,6例 CO≤4.5 L/min;SVRI均≤1700 mm Hg·min/(L·m2),EVLWI、PVPI则在正常范围内;CVP≥12 mm Hg的患者有8例,CVP≤6 mm Hg有18例,余下患者CVP在8～12 mm Hg.经EGDT方案治疗后,各组的GEDVI、CVP值较前升高,HR下降,MAP回升,但死亡组在6 h甚至12 h仍未至65 mm Hg;与死亡组相比,存活组患者的CO、SVRI、EVLWI和PVPI均差异有统计学意义,而且随时间的推移,死亡组患者CO进行性降低、EVLWI及PVPI则进行性升高(P<0.01).结论 脓毒性休克患者存在高排低阻的血流动力学特点;即便一开始表现为低心排,经液体复苏后也会表现为高心排;持续低心排、进行性EVLWI、PVPI升高,提示预后不良.与CVP相比,GEDVI更能有效地指导脓毒性休克患者的液体复苏.     

PiCCO监测下的感染性休克早期液体复苏对血管外肺水的影响

目的:探讨感染性休克早期应用PiCCO监测液体复苏后血管外肺水的变化特点。方法:选择48例入住ICU存在血容量不足胸腔内血容积指数[(ITBVI)<750 mL/m2]的感染性休克早期患者,根据血管外肺水指数(EVLWI)是否大于7 mL/kg分为肺水正常和肺水偏高两组。两组患者均给予羟乙基淀粉130/0.4氯化钠注射液(万汶)按250 mL/15 min的速度行早期液体复苏,使其ITBVI>850 mL/m2,监测两组患者复苏前、复苏终点后即刻、复苏终点后2 h及6 h的EVLWI、氧合指数(PaO2/FiO2)和血流动力学等指标水平的变化。结果:液体复苏扩容对ITBVI、GEDVI、CI、SVI、CVP、EVLWI有影响(P<0.05),两组液体复苏达终点后的即刻、2 h、6 h各时间点的ITBVI、GEDVI与复苏前相比均有增加,差异有统计学意义(P<0.01)。两组PaO2/FiO2各时间点与复苏前相比,差异均无统计学意义(P>0.05)。肺水正常组的CI、SVI各时间点与复苏前比较,差异均无统计学意义(P>0.05);但肺水偏高组的CI在复苏达终点后即刻和2 h两个时间点与复苏前比较有增加(P<0.01),SVI在复苏终点后2 h和6 h两个时间点与复苏前比较有增加(P<0.01)。CVP与复苏前相比,肺水正常组仅复苏终点后6 h有增加(P<0.01),肺水偏高组复苏终点后2、6 h均有增加(P<0.01)。EVLWI与复苏前相比,复苏达终点后的即刻、2 h、6 h均有增加(P<0.05)。结论:感染性休克早期进行液体复苏可使GEDVI、ITBVI、CI、SVI增加,对CVP和EVLWI也有一定程度的影响,但不影响氧合功能。     

呼气末正压对血管外肺水及氧合的影响

目的 探讨不同水平的呼气末正压(PEEP)对接受机械通气的感染性休克患者血管外肺水指数(EVLWI)及氧合指数(PaO2/FiO2)的影响.方法 采用前瞻性、干预性的研究方法对北京协和医院MICU 15例行机械通气的感染性休克患者应用跨肺热稀释法及持续脉搏轮廓的方法进行血流动力学监测(PiCCO plus).所有患者采用容量控制通气,血流动力学稳定后,每隔1 h递增PEEP水平,PEEP从0增加到20 cm H2O(如果能耐受),根据不同的PEEP水平分为五组(0、5、10、15、20 cm H2O).应用one-way ANOVA和Pearson's进行统计分析及相关分析,观察不同水平的PEEP对EVLWI、PaO2/FiO2的影响及其相关性.结果 15例感染性休克患者,男10例(67%),女5例(33%),平均年龄(67.6 ± 19.5)岁,APACHEⅡ评分(22.1 ± 7.5)分,基础PEEP( 8.5 ± 3.6 )cm H2O, 基础PaO2/FiO2(225.6 ± 89.2)mm Hg,ICU病死率67.6%.随着PEEP的升高,PaO2/FiO2升高,各组间比较差异有统计学意义(P＜0.05),PEEP 对EVLWI及肺毛细血管通透性(PVPI)无明显影响.PaO2/FiO2与EVLWI、PVPI呈负相关(PaO2/FiO2 vs. EVLWI: r=-0.258,P=0.034;PaO2/FiO2 vs. PVPI: r=-0.324,P=0.007).结论 短时间应用PEEP 能改善氧合,但不降低 EVLWI.     

PiCCO监测在神经源性肺水肿患者中的应用研究

目的 探讨脉搏指示连续心排血量(PiCCO)监测在神经源性肺水肿(NPE)患者中的应用,评估容量参数胸腔内血容量指数(ITBVI)、全心舒张期末容量指数(GEDVI)及压力参数中心静脉压(CVP)对NPE严重程度评估的准确性,评价血管外肺水指数(EVLWI)对NPE患者预后判断的意义.方法 采用前瞻性临床观察研究方法,对36例并发NPE的神经科危重患者,采用PiCCO监测平均动脉压(MAP)、心排血指数(CI)、CVP、ITBVI、GEDVI、EVLWI、肺血管通透性指数(PVPI)等指标,ITBVI、GEDVI、CVP与EVLWI之间进行相关性分析;根据患者结局分为死亡组与存活组,比较两组在治疗前及治疗3d的EVLWI变化.结果 EVLWI与ITBVI呈显著正相关(r=0.54,P＜0.001),与GEDVI呈显著正相关(r=0.62,P＜0.0001),而与CVP无显著相关性(r=0.12,P＞0.05);PVPI、EVLWI与氧合指数(PaO2/FiO2)均呈显著负相关(r=-0.55、P＜0.001,r=-0.48、P＜ 0.05).存活组与死亡组治疗前EVLWI(ml/kg)水平差异无统计学意义(8.6±2.6比9.4±1.8,P＞0.05);存活组治疗3d后EVLWI水平明显低于治疗前(6.92±1.64比8.64±2.62,P＜0.05),且明显低于死亡组治疗3d后(6.92±1.64比9.88±2.44,P＜0.05).结论 容量参数GEDVI、ITBVI比压力参数CVP评估NPE患者的EVLWI更为准确、可靠;NPE患者PVPI、EVLWI越高,PaO2/FiO2越低;动态观察NPE患者的EVLWI可评估预后.     

血管外肺水指数在脓毒症相关性ALI/ARDS患者液体管理中的意义

目的 通过观察严重脓毒症/脓毒性休克患者血管外肺水指数(extravascular lung water index,EVLWI)与氧合指数(PaO2/FiO2)和胸腔内血容量指数(intrathoracic blood volume index,ITBVI)的相关性,探讨血管外肺水在脓毒症相关性急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)患者液体管理中的指导意义,为脓毒症相关性ALI/ARDS患者的液体管理提供新的临床策略.方法 选择2006年4月至2008年4月浙江大学医学院附属第二医院重症医学科符合严重脓毒症/脓毒性休克伴ALI/ARDS患者24例,应用PiCCO技术监测患者胸腔内血容量指数(ITBVI)和血管外肺水指数(EVLWI),用血气分析同时监测动脉血氧分压(PaO2),以PaO2/吸入氧浓度(FiO2)计算氧合指数.比较EVLWI与PaO2/FiO2和ITBVI与EVLWI之间的相关性.采用简单相关分析法进行统计学分析.结果 EVLWI与PaO2/FiO2呈明显负相关(r=-0.45,P＜0.01).进一步以EVLWI=14 mL/kg进行分层分析,当EVLWI≤14 mL/kg时,两者无明显相关性(r=0.12,P=0.243);当EVLWI＞14 mL/kg时,两者呈明显负相关(r=-0.47,P＜0.01).这可以提示对严重脓毒症/脓毒性休克伴ALI/ARDS患者,EVLW不是影响氧合的唯一因素,当EVLWI＞14 mL/kg时,可以通过降低EVLW来改善氧合,但更应综合考虑影响氧合指数的各种因素.ITBVI与EVLWI无明显相关性(r=0.02,P=0.84).进一步以ITBVI=1000 mL/m2进行分层分析,当ITBVI≤1000 mL/m2时,两者无明显相关性(r=0.13,P=0.17);当ITBVI＞1000 mL/m2时,两者呈明显正相关(r=0.40,P＜0.01).这提示我们对于脓毒症相关性ALI/ARDS,当ITBVI＞1000mL/m2时,可以通过降低ITBV来降低EVLW,但对于肺毛细血管通透性增高症引起的EVLW,不能通过降低ITBV来降低.结论 EVLW在脓毒症相关性ALI/ARDS的液体管理中具有重要指导意义.     

不同晶胶比液体复苏对重症急性胰腺炎患者血管外肺水指数的影响

目的 探讨不同晶胶比液体复苏对重症急性胰腺炎(SAP)患者血管外肺水(EVLW)的影响.方法 回顾性分析本院2009年1月至2010年12月重症医学科24例SAP患者的临床资料.所有患者的胸内血容量指数(ITBVI)均＜750 ml/m2,以ITBVI 850～1 000 ml/m2作为复苏终点.以晶胶比3:1为界,将患者分成低晶胶比组(13例)和高晶胶比组(11例),观察液体复苏前及复苏后即刻(0)、24、48、72 h患者血流动力学、血管外肺水指数(EVLWI)、氧合指数(PaO2/FiO2)、膀胱内压(ICP)、B型钠尿肽(BNP)的变化;采用脉搏指示连续心排血量(PiCCO)热稀释法测定EVLWI,用放射免疫法测定BNP.结果 ①早期采用不同晶胶比液体复苏均可改善SAP患者血流动力学指标.②复苏后72 h高晶胶比组总液体量[(16 438±1 758)ml]、晶体液量[(13 459±425)m1]及晶/胶比值(4.50±0.23)均明显高于低晶胶比组[分别为(13 895±1 783)ml、(6 945±454)ml、2.32±0.18,P＜0.05或P＜0.01].③与低晶胶比组比较,高晶胶比组复苏后48 h和72 hPaO2/FiO2(mm Hg,1 mm Hg=0.133 kPa)明显下降(48 h:186.51±42.26比268.35±34.18,72 h:172.85±21.50比263.95±24.20),EVLWI、ICP及BNP均明显升高[EVLWI(ml/kg)48 h:14.52±1.08比10.40±1.16,72 h:14.92±0.86比10.52±1.02;ICP(cm H2O,1 cm H2O=0.098 kPa)48 h:16.23±1.32比13.05±1.70,72 h:17.39±1.56比13.42±1.65;BNP(ng/L)48 h:424.29±74.25比225.32±53.58,72 h:620.49+79.53比288.28±68.78,P＜0.05或P＜0.01].④Pearson相关分析显示:EVLWI与PaO2/FiO2呈显著负相关(r=-0.71,P＜0.01),与ICP、BNP呈显著正相关(r1=0.63,r2=0.56,均P＜0.01).结论 对SAP患者早期应监测EVLWI、ICP及BNP以指导液体复苏,且宜采用提高胶体比例的限制性液体复苏策略.     

血管外肺水量能反映脓毒症时肺损伤严重程度

经肺热稀释法可以测定并计算血管外肺水量指数（EVLWI）和肺血管通透性指数。为确定上述指标能否反映脓毒性休克时急性肺损伤的严重程度，国外研究人员进行了一项前瞻性研究，该研究共纳入38例脓毒性休克并发急性肺损伤的重症监护室（ICU）患者，测定其入院72h内血流动力学指标、EVLWI、肺血管通透性指数、肺顺应性、氧合指数（PaO2／FiO2）、肺损伤指数、血小板计数和血浆内皮素-1浓度。     

不同液体管理策略对急性呼吸窘迫综合征患者血管外肺水指数的影响

目的 通过观察不同液体管理策略对急性呼吸窘迫综合征(ARDS)患者血管外肺水指数(EVLWI)、氧合指数(PaO2/FiO2)、24 h液体平衡量、机械通气时间、住ICU时间的影响,探寻ARDS患者的最佳液体管理策略.方法 选取符合入选标准的ARDS患者为研究对象,随机分为保守性液体管理策略组(保守组)和开放性液体管理策略组(开放组),动态监测中心静脉压(CVP)、平均动脉压(MAP)、心脏指数(CI)、PaO2/FiO2、尿量及EVLWI等,记录24 h液体平衡量、机械通气时间及住ICU时间.结果 保守组除第1天外每日液体均处于负平衡,而开放组每日液体均处于正平衡.保守组EVLWI下降程度、PaO2/FiO2改善程度明显好于开放组,机械通气时间、住ICU时间明显短于开放组(P均<0.05).结论 保守性液体管理策略可以明显降低ARDS患者血管外肺水,改善肺功能,缩短ARDS患者机械通气时间和住ICU时间.保守性液体管理策略是降低血管外肺水的有效治疗手段.     

PiCCO在ARDS合并感染性休克的老年患者早期目标导向治疗中的应用

目的:探讨脉波指示剂连续心排血量监测(PiCCO)技术在急性呼吸窘迫综合征(ARDS)合并感染性休克的老年患者早期目标导向治疗(EGDT)中的临床指导价值.方法:将88例ARDS合并感染性休克的老年患者随机分成治疗组和对照组,治疗组采用PiCCO技术指导下EGDT,对照组按规常进行EGDT.记录两组患者6、24 h各项参数,6、24 h达标率及30 d病死率等参数.结果:治疗组6、24 h复苏液体量显著多于对照组(P＜0.01),血管活性药物用量显著少于对照组(P＜0.05);复苏24 h的MAP、CVP、ScvO2、每小时尿量、氧合指数(PaO2/FiO2)、全心舒张末期容积指数(GEDI)、胸腔内血容量指数(ITBVI)、心排指数(CI)、6、24 h达标率显著高于对照组(P＜0.05);血清乳酸浓度(Lac)、血管外肺水指数(EVLWI)、全身血管阻力指数(SVRI)、肺血管通透性指数(PVPI)、30 d病死率显著低于对照组(P＜0.05).结论:PiCCO指导下液体复苏在ARDS合并感染性休克的老年患者EGDT中具有积极的临床意义.     

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.