心肌做功技术评估急性心肌梗死患者左心室收缩功能

目的 探讨心肌做功（MW）技术评估急性心肌梗死（AMI）患者左心室收缩功能的应用价值。方法 对比30例AMI患者（AMI组）与30名健康志愿者（对照组）的常规超声心动图参数及MW参数，分析AMI患者左心室整体有用功（GCW）与左心室射血分数（LVEF）、整体长轴应变（GLS）之间的相关性。结果 与对照组比较，AMI组左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVESD）、室间隔舒张末期厚度（IVSD）、左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、二尖瓣口舒张早期峰值流速（E）/二尖瓣后叶瓣环组织多普勒速度（e）、左心室质量（LVM）、左心室质量指数（LVMI）及二尖瓣反流面积（MR）均增大，LVEF、E及e值均减低（P均<0.05）；左心室GCW、整体做功效率（GWE）、整体做功指数（GWI）均降低，整体无用功（GWW）、GLS、峰值应变离散度（PSD）均增高（P均<0.05）。AMI患者GCW与LVEF呈正相关（r=0.573，P=0.001），GCW与GLS呈负相关（r=-0.880，P<0.001）。结论 MW技术可用于评估AMI患者左心室收缩功能变化。     

三维斑点追踪成像(3D-STE)定量评价容量负荷改变后左心室整体应变情况

目的 采用三维斑点追踪成像(3D-STE)定量评价容量负荷改变后左心室整体应变情况。方法 选取动脉导管未闭(PDA)患者(PDA组)、继发型房间隔缺损(ASD)患者(ASD组)及健康体检者(对照组)各35人,分析其常规超声及3D-STE资料;比较组间左心室舒张末期内径(LVEDD)、收缩末期内径(LVESD)、后壁舒张末期厚度(LVPWT)、室间隔厚度(IVST)、左心室舒张末期容积(LVEDV)、收缩末期容积(LVESV)、射血分数(LVEF)、肺动脉内径(PAD)、肺动脉收缩压(PAP)、左心室整体纵向/圆周/径向/面积应变(GLS/GCS/GRS/GAS),观察PDA及ASD组左心室GAS的影响因素;评估3D-STE评价左心室容量负荷改变后其三维整体应变的价值。结果 3组LVEDD、LVESD、LVEDV、LVESV、LVEF、PAD及PAP差异均有统计学意义(P均＜0.05);组间两两比较,LVEDD、LVESD、LVEDV、LVESV及PAD差异均有统计学意义(P均＜0.05),PDA组及对照组LVEF均高于ASD组(P均＜0.05),PDA组PAP高于ASD组和对照组(P均＜0.05)。3组左心室GLS、GCS、GRS及GAS差异均有统计学意义(P均＜0.05),两两比较,组间GCS、GRS及GAS差异均有统计学意义(P均＜0.05);PDA组GLS高于ASD及对照组(P均＜0.05)。PDA组左心室GAS与PAD、LVEDD、LVESD、LVEDV、LVESV、动脉导管内径及长度均呈线性相关(P均＜0.01),其中PAD、LVEDV及LVESV为主要影响因素(P均＜0.05);ASD组左心室GAS与缺损处宽度、LVEDD、LVEDV、LVESV及LVEF均呈线性相关(P均＜0.05),其中缺损处宽度为主要影响因素(P＜0.01)。结论 3D-STE可定量评价容量负荷改变后左心室三维整体应变,其面积应变与容量负荷呈线性相关,即左心室心肌纤维随容量负荷改变而发生重塑。     

超声三维斑点追踪成像评价系统性红斑狼疮左心室整体收缩功能

目的 探讨三维斑点追踪成像(3D-STI)对系统性红斑狼疮(SLE)左心室整体收缩功能变化的诊断价值。方法 分别对30例SLE患者(SLE组)及30名健康志愿者(对照组)行二维超声心动图和3D-STI检查。二维超声心动图测量左心室射血分数(LVEF)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、每搏输出量(SV)、舒张早期二尖瓣跨瓣血流速度(E)和舒张晚期二尖瓣跨瓣血流速度(A)。应用3D-STI行心肌运动分析,测量左心室整体纵向、圆周、径向及面积收缩期峰值应变(GLS、GCS、GRS、GAS)。对两组上述参数进行统计学分析。结果 SLE组二维超声心动图的测量数值(LVEDD、LVESD、LVEF、SV、E、A)与对照组比较,差异均无统计学意义(P均>0.05)。SLE组左心室GLS、GCS、GRS、GAS均较对照组减低,差异均有统计学意义(P均<0.05)。GLS诊断SLE的敏感度及特异度分别为93.3%、96.7%,GAS分别为90.0%、83.3%,高于GCS(80.0%、86.7%)和GRS(73.3%、76.7%)。结论 3D-STI可早期检测SLE左心室收缩功能异常。     

快速评估心脏MR左心室长轴应变及其与左心室整体纵向应变的相关性

目的 探讨快速评估左心室长轴应变（LAS）的方法及其与左心室整体纵向应变（GLS）的相关性。方法 对77名健康志愿者行心脏MR检查,于收缩末期和舒张末期分别测量二尖瓣瓣环插入点连线中点与左心室心尖的心外膜边缘的距离（方法1）、二尖瓣室间隔侧插入点与左心室心尖的心外膜边缘的距离（方法2）以及二尖瓣瓣环游离壁插入点与左心室心尖的心外膜边缘的距离（方法3）,计算3种方法的LAS值,并测量左心室心功能参数及GLS,比较3种LAS测值的差异,并分析其与GLS的相关性。取3种LAS值的均值,观察LAS及GLS与左心室射血分数（LVEF）的相关性。分析观察者间及观察者内测量上述参数的一致性。结果 3种方法所测LAS值差异无统计学意义（F=0.97,P=0.41）。方法1的LAS值与GLS呈显著正相关（r=0.86,P<0.001）,方法2的LAS值与GLS呈中度正相关（r=0.57,P<0.001）,方法3的LAS值与GLS呈较好正相关（r=0.64,P<0.001）。LAS及GLS与LVEF均呈中度负相关（r=-0.38、-0.42,P=0.04、0.02）。观察者内和观察者间一致性均好（ICC均>0.75）。结论 通过计算不同位点在心脏舒张和收缩末期相对位移的百分比可快速、简便评估LAS,且后者与GLS呈正相关。     

三维面积应变评价射血分数保留心力衰竭患者左心室收缩功能变化

目的 应用整体面积应变（GAS）评价射血分数保留的心力衰竭（HFpEF）患者左心室心肌收缩功能早期变化情况。方法 收集32例HFpEF患者和32名健康志愿者,采集二维超声心动图、组织多普勒（TDI）与三维斑点追踪（3D-STI）图像,测量左心房收缩末期前后径（LAd）、左心室舒张末期前后径（LVEDd）、室间隔的舒张末期厚度（IVSTd）、左心室后壁舒张末期厚度（LVPWTd）,二尖瓣口血流舒张早期峰速（E）和舒张晚期峰速（A）、舒张早期二尖瓣环运动速度（e''）和E/e''比值以及左心室舒张末期容积（LVEDV）、收缩末期容积（LVESV）、射血分数（LVEF）和GAS;比较两组间各参数差异,以Pearson相关分析评价GAS与LVEF间的相关性。结果 HFpEF组LVEDd、E、LVEDV、LVESV及LVEF与对照组差异均无统计学意义（P均>0.05）。HFpEF组LAd、IVSTd、LVPWTd、A、E/e''升高,E/A、e''减低（P均<0.05）。HFpEF组左心室GAS峰值[（-18.36±8.48）%]明显低于对照组[（-25.12±4.76）%],差异有统计学意义（P均<0.05）;GAS值与LVEF呈负相关（r=-0.50,P<0.05）。结论 HFpEF患者在早期LVEF未发生明显变化时即已存在左心室整体收缩功能减低,可通过3D-STI测量GAS而予以定量评价。     

三维斑点追踪技术评价2型糖尿病合并非酒精性脂肪性肝病患者左心室功能

目的 探讨三维斑点追踪（3D-STE）技术评估2型糖尿病（T2DM）合并非酒精性脂肪性肝病（NAFLD）患者左心室功能的可行性。方法 对30例T2DM不合并NAFLD（A组）、32例T2DM合并轻度NAFLD（B组）及35例T2DM合并中重度NAFLD患者（C组）行3D-STE检查,检测常规参数,包括二尖瓣口舒张早期与晚期峰值血流速度比值（E/A）、舒张末期室间隔厚度（IVSTd）、左心室下侧壁厚度（PWTd）及舒张末期左心室内径（LVDd）、收缩末期左心室内径（LVDs）,左心室功能参数包括收缩末期左心房容积（LAV）、左心室质量（LVM）、左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心室质量指数（LVMI）、左心室射血分数（LVEF）,以及3D-STE应变参数左心室整体纵向应变（GLS）、整体面积应变（GAS）、整体径向应变（GRS）和整体圆周应变（GCS）。以Pearson线性相关分析3D-STE参数与糖化血红蛋白（HbA1c）、体质量指数（BMI）的相关性。结果 3组E/A、IVSTd、PWTd、LVDd、LVDs、LVMI、LVEF、LVEDV及LVESV差异均无统计学意义（P均>0.05）,A、B组GRS、GCS、GLS、GAS均较C组增加（P均<0.05）。GLS、GRS、GCS、GAS与HbA1c均呈负相关（r=-0.540、-0.476、-0.489、-0.623,P=0.040、0.032、0.037、0.020）,与BMI均无相关性（P均>0.05）。结论 3D-STE可用于评价T2DM合并NAFLD患者左心室功能。     

心血管MR组织追踪技术定量评估肥厚型心肌病右心室心肌应变

目的 探讨心脏MR组织追踪（CMR-TT）技术评价肥厚型心肌病（HCM）右心室功能的可行性及右心室应变与左心室应变的相关性。方法 对32例HCM患者（HCM组）及32名健康志愿者（对照组）行CMR电影序列扫描,测量心功能及左、右心室应变参数。结果 HCM组左心室质量较对照组明显增高（t=11.26,P<0.001）,其余左心功能参数（左心室射血分数、舒张末期容积、收缩末期容积）2组间差异均无统计学意义（P均>0.05）。与对照组比较,HCM组左心室、右心室整体圆周应变（GCS）、整体径向应变（GRS）和整体纵向应变（GLS）均明显减低（P均<0.05）;除左、右心室基底部径向应变外,HCM组各节段局部应变较对照组减低（P均<0.05）。HCM组右心室GRS与左心室GRS呈正相关（r=0.375,P=0.034）,与左心室GLS呈负相关（r=-0.466,P=0.007）;右心室GCS与左心室GCS、GLS均呈正相关（r=0.531、0.462,P=0.002、0.008）。结论 右心室节段应变、整体应变能敏感地反映HCM右心室心肌收缩功能;HCM患者在左心室射血分数减低前左、右心室心肌收缩功能已存在受损;HCM右心室与左心室心肌收缩功能受损存在一定相关性。     

左心室整体纵向应变预测急性心肌梗死患者经皮冠状动脉介入术后左心室重构

目的 探讨应用二维斑点追踪(STE)技术预测急性心肌梗死(AMI)患者经皮冠状动脉介入(PCI)术后左心室重构(LVR)的价值。方法 对75例AMI患者于PCI术后72 h及6个月行STE检查,测算左心室整体圆周应变(GCS)及整体纵向应变(GLS)。以术后6个月左心室舒张末期容积(LVEDV)≥15%作为LVR诊断标准。进行统计学分析。结果 PCI术后6个月,75例中56例未发生重构(非重构组),19例发生LVR(重构组),发生率25.33%(19/75)。与术后72 h比较,重构组术后6个月LVEF减低,非重构组术后6个月LVEF增高(P均<0.05)。与非重构组比较,重构组术后72 h及术后6个月GCS及GLS均减低(P均<0.05)。LVEF、GCS及GLS均与LVR呈负相关(r=-0.39、-0.52、-0.64,P均<0.01)。GLS及GCS是LVR的独立预测因子。GLS的ROC曲线下面积最大,预测LVR的阈值为-12.45%,敏感度和特异度分别为86.3%及87.2%。STE参数测量观察者间差异为(9.32±3.14)%,观察者内差异为(7.18±2.26)%。结论 通过STE测得的GLS可用以准确预测AMI患者PCI术后LVR。     

三维斑点追踪技术评价左心室射血分数正常的重度主动脉瓣狭窄患者主动脉瓣置换术后左心室心肌功能

目的采用三维斑点追踪(3D-STI)技术观察左心室射血分数(LVEF)正常的重度主动脉瓣狭窄(AS)患者主动脉瓣置换术(AVR)后左心室心肌功能改变特点,并评价其临床应用价值。方法选取2014年10月至2016年10月南京医科大学附属南京医院收治的拟行AVR的重度AS患者40例(重度AS组)和健康志愿者40名(健康对照组)。健康对照组受试者行常规超声心动图和3D-STI测量,重度AS组患者分别于术前、术后1周及术后3个月行常规超声心动图和3D-STI测量,获得左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、室间隔厚度(IVSD)、左心室后壁厚度(LVPWD)、左心室射血分数(LVEF)、左心室整体纵向应变(GLS)、左心室整体环向应变(GCS)、左心室整体径向应变(GRS)、左心室整体面积应变(GAS)及三维应变(3D-strain)。采用独立样本t检验分别比较重度AS组患者术前、术后3个月与健康对照组受试者常规超声参数、三维应变参数;采用单因素方差分析比较重度AS组患者术前、术后1周及术后3个月常规超声参数、三维应变参数,进一步组间两两比较采用LSD-t检验。结果与健康对照组受试者比较,重度AS组患者术前IVSD、LVPWD均增大,GLS、GRS、3D-strain均降低,GCS升高,且差异均有统计学意义(t=13.824、11.298、10.221、-6.237、-5.674、-6.584,P均0.001),而LVEDD、LVESD、GAS差异均无统计学意义;与术前比较,重度AS组患者术后1周LVEF、GLS、GCS、GAS均降低,且差异均有统计学意义(t=-2.205、-2.093、-2.034、-3.152,P均0.05或0.01),而LVEDD、LVESD、IVSD、LVPWD、GRS、3D-strain差异均无统计学意义;重度AS组患者术后3个月GLS、GRS、3D-strain均升高,GCS、IVSD、LVPWD均降低,且差异均有统计学意义(t=5.446、-4.923、-4.388、-3.988、4.794、4.211,P均0.05或0.01),而LVEDD、LVESD、LVEF、GRS、GAS差异均无统计学意义。与术后1周比较,重度AS组患者术后3个月LVEF、GLS、GRS、GAS、3D-strain均升高,GCS、IVSD、LVPWD均降低,且差异均有统计学意义(t=-2.631、7.383、-4.719、2.923、-4.154、-2.109、4.747、4.323,P均0.05或0.01),而LVEDD、LVESD差异均无统计学意义。重度AS组患者术后3个月IVSD、LVPWD、GLS及GCS仍高于健康对照组受试者,且差异均有统计学意义(t=9.809、7.066、4.752、-2.553,P0.001或0.01),而LVEDD、LVESD、LVEF、GRS、GAS、3D-strain差异均无统计学意义。结论 LVEF正常的重度AS患者,其左心室心肌功能的改变及其接受AVR后的心肌功能变化均有一定特征性,3D-STI技术能较准确地对其进行评价。     

三维斑点追踪成像评价肿瘤患者胸部放射治疗后左心室收缩功能变化

目的 探讨三维斑点追踪成像（3D-STI）评价胸部放射治疗前后左心室收缩功能变化的价值。方法 选取拟接受首次胸部放射治疗且照射野累及心脏的恶性肿瘤患者35例,分别于放射治疗前后行超声检查。采集连续6个心动周期的左心室三维全容积图像并储存,计算左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心室每搏输出量（LVSV）、左心室射血分数（LVEF）、左心室质量（LVMASS）、左心室整体面积收缩期峰值应变（GAS）、左心室整体圆周收缩期峰值应变（GCS）、左心室整体纵向收缩期峰值应变（GLS）及左心室整体径向收缩期峰值应变（GRS）;比较放射治疗前后上述指标的变化情况。结果 放射治疗前与治疗后LVEDV、LVESV、LVEF、LVSV及LVMASS差异均无统计学意义（P均<0.05）。放射治疗后GCS、GAS、GRS均较放射治疗前降低（P均<0.05）,但GLS无明显改变（P>0.05）。结论 胸部肿瘤患者放射治疗后左心室GCS、GAS、GRS已发生改变,3D-STI可发现放射治疗后心脏早期损伤。     

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.