超声联合声触诊组织成像定量技术评估颈动脉斑块及预测脑梗死的临床价值

目的应用声触诊组织成像定量(VTIQ)技术评价颈动脉斑块软硬度诊断脑梗死的可行性、稳定性及预测价值,探讨超声联合VTIQ技术预测脑梗死的临床应用价值。方法选取60例脑梗死患者(脑梗死组)和40例非脑梗死患者(非脑梗死组),根据斑块总风险评分标准筛选出代表性斑块行超声和VTIQ检查。记录斑块回声类型、颈动脉狭窄率和剪切波速度(SWV),比较两组患者斑块的回声类型构成比、颈动脉狭窄率及SWV。应用Bland-Altman分析检验高年资医师和低年资医师间测量SWV的一致性。绘制受试者工作特征(ROC)曲线分析不同参数独立预测脑梗死的诊断效能,Logistic回归分析结合ROC曲线分析多参数联合预测脑梗死的诊断效能。结果两组斑块的回声类型构成比及颈动脉狭窄率比较差异均有统计学意义(均P0.01),脑梗死组SWV显著低于非脑梗死组[(3.32±0.92)m/s vs.(3.76±0.85)m/s,P=0.004]。斑块回声类型、颈动脉狭窄率、SWV诊断脑梗死的曲线下面积(AUC)分别为0.291、0.722、0.664。不同观察者间测量SWV的一致性偏倚为0.0556 m/s,一致性界限为-0.3937～0.5049 m/s。以SWV≤3.435 m∕s为截断值,诊断脑梗死的敏感性、特异性、准确率分别为60.00%、62.50%、70.50%;斑块回声类型与颈动脉狭窄率联合诊断脑梗死的曲线下面积为0.806,敏感性、特异性、准确率分别为68.33%、82.50%、74.00%;斑块回声类型、颈动脉狭窄率和SWV三者联合诊断脑梗死的曲线下面积为0.945,敏感性、特异性、准确率分别为91.67%、82.50%、88.00%。结论应用VTIQ技术评价颈动脉斑块软硬度诊断脑梗死具有较好的可行性和可重复性,VTIQ联合超声可提高脑梗死的诊断准确率。     

超声造影联合声触诊组织成像定量技术对乳腺癌前哨淋巴结转移的评估

目的探讨超声造影（CEUS）联合声触诊组织成像定量（VTIQ）技术在术前评估乳腺癌前哨淋巴结（SLN）转移中的临床价值。 方法收集2019年6月至2020年1月因乳腺癌收住哈尔滨医科大学附属第一医院的患者,共72例患者的72个SLN纳入研究。所有患者均行手术治疗并取得病理结果,术前均行常规超声、CEUS及剪切波弹性成像检查。根据术后病理结果将SLN分为转移组21个和非转移组51个。比较2组SLN的超声造影模式及VTIQ剪切波速度（SWV）值。绘制ROC曲线比较超声造影、SWV及联合诊断预测乳腺癌SLN转移的效能。 结果转移性SLN与非转移性SLN的CEUS增强模式比较,差异有统计学意义（χ²=25.53,P=0.000）,2组VTIQ的SWV最大、最小、平均值比较,差异均有统计学意义（t=7.79、7.12、8.75,P均=0.000）。CEUS判断SLN转移的ROC曲线下面积（AUC）为0.829,最佳截断值为1.5,即I型增强模式为非转移性,II、III、IV型增强模式为转移性。以最佳截断值为SLN转移的判定标准,敏感度、特异度、阳性预测值、阴性预测值分别为85.71%、70.59%、54.54%、92.31%。绘制SWV最大值、最小值及平均值诊断SLN转移的ROC曲线,AUC分别为0.910、0.873、0.937,最佳截断值分别为3.06、2.23、2.64 m/s。以SWV平均值2.64 m/s为判定标准,敏感度、特异度、阳性预测值和阴性预测值分别为76.19%、94.23%、88.89%和90.74%。联合CEUS与VTIQ诊断SLN转移的敏感度、特异度、阳性预测值、阴性预测值分别为95.24%、96.08%、90.91%、96.08%。绘制CEUS与VTIQ联合方法诊断SLN转移的ROC曲线,AUC为0.957。 结论CEUS联合VTIQ技术可以提高乳腺癌淋巴结转移的诊断效能,为乳腺癌术前腋窝淋巴结评估提供可靠依据。     

Logistic回归模型评价常规超声联合声触诊组织成像定量技术诊断三阴性乳腺癌的价值

目的 利用Logistic回归模型评价常规超声联合声触诊组织成像定量技术(VTIQ)对三阴性乳腺癌(TNBC)的诊断价值。方法 回顾性分析170例乳腺癌患者的术前常规超声及VTIQ的声像图特征,应用曲线下面积（AUC）比较分析VTIQ各参数诊断TNBC的价值, 筛选出诊断TNBC最有价值的指标, 并建立常规超声联合VTIQ诊断TNBC的二分类Logistic回归模型。结果 TNBC和non-TNBC的最大SWV值、平均SWV值、最小SWV值、平均SWV值/正常乳腺值两组间比较差异均有统计学意义（P均＜0.01）, 根据AUC显示最大SWV值的诊断效能最佳。多因素Logistic回归分析后显示诊断TNBC的超声特征为边缘不光整伴分叶、后方回声增强、形态规则、最大SWV值＜6.98m/s。该Logistic模型具有统计学意义（2=68.128,P＜0.01）,该模型的敏感度、特异度、阳性预测值、阴性预测值分别为80.6%、85.7%、72.0%、87.6%。结论 常规超声联合VTIQ的Logistic回归模型对TNBC有较高的诊断效能,可作为预测TNBC的一项重要参考指标。     

二维超声联合声触诊组织成像定量技术诊断唾液腺干燥综合征

目的 观察二维超声联合声触诊组织成像定量（VTIQ）技术诊断唾液腺干燥综合征（SS）的价值。方法 收集43例SS患者（SS组）和60例非SS患者（对照组）,观察并对比其唾液腺病灶二维超声评分及剪切波速度（SWV）,绘制受试者工作特征（ROC）曲线,评估二维超声评分、VTIQ及二者联合诊断唾液腺SS的效能。结果 SS组唾液腺二维超声评分及唾液腺SWV均明显高于对照组（P均<0.01）。以2.12、2.38 m/s为唾液腺（腮腺、下颌下腺）SWV最佳截断值,其诊断唾液腺SS的敏感度、特异度、约登指数和曲线下面积（AUC）分别为83.70%、88.30%、0.72和0.90;以二维超声评分2分为最佳截断值,其诊断唾液腺SS的敏感度、特异度、约登指数和AUC分别为76.70%、90.00%、0.67和0.91;以二维超声评分为1分且唾液腺SWV=2.12、2.38 m/s为最佳截断值,联合诊断唾液腺SS的敏感度、特异度、约登指数和AUC分别为95.30%、60.00%、0.55和0.78。结论 二维超声联合VTIQ技术有助于诊断唾液腺SS。     

声触诊组织成像定量技术鉴别乳腺硬化性腺病与浸润性导管癌的价值

目的 探讨声触诊组织成像定量技术(VTIQ)鉴别诊断乳腺硬化性腺病(SA)和浸润性导管癌(IDC)的价值。方法 回顾性分析经手术病理确诊的55例SA患者和64例IDC患者的常规超声和VTIQ图像特征。绘制VTIQ、乳腺影像报告和数据系统(BI-RADS)分类及两者联合鉴别诊断SA与IDC的受试者工作特征(ROC)曲线，计算曲线下面积(AUC),比较BI-RADS分类及VTIQ技术联合BI-RADS分类的诊断效能。结果 ROC曲线显示，剪切波速度(SWV)最大值(SWV_max)、SWV最小值(SWV_min)、SWV平均值(SWV_mean)、SWV中位数(SWV_median)鉴别诊断SA与IDC的AUC分别为0.85、0.79、0.83、0.83,其中SWV_max诊断效能最高，诊断截断值为4.90 m/s; BI-RADS分类及VTIQ技术联合BI-RADS分类鉴别诊断SA与IDC的AUC分别为0.58、0.81。结论 VTIQ技术联合BI-RADS分类可提高SA的诊断效能。     

VTIQ技术测量剪切波速度以及速度比值对乳腺良恶性结节的诊断价值

目的 探讨声触诊组织量化成像（virtual touch tissue imaging quantification,VTIQ）技术测量剪切波速度以及速度比值对乳腺良恶性结节鉴别的诊断价值。 方法　回顾性分析经手术后病理证实的46例患者46个乳腺实性病灶的VTIQ图像资料。测量良恶性病灶、周围乳腺腺体组织在VTIQ上的剪切波速度（Shear wave velocity,SWV）,计算良恶性病灶SWV平均值以及良恶性病灶与周围乳腺腺体组织SWV平均值比值,绘制受试者操作特性（receiver operating characteristic curve,ROC）曲线,并进行曲线下面积比较,分析评估VTIQ技术对乳腺良恶性结节鉴别的诊断价值。 结果　46个乳腺病灶中,恶性病灶18个,良性病灶28个。良恶性病灶的SWV值有统计学意义（p＜0.05）。良恶性病灶与周围乳腺腺体组织SWV值比值有统计学意义（p＜0.05）。良恶性病灶SWV值ROC曲线：AUC为0.875,截断值为4.52,准确性84.80%,敏感性88.89%,特异性82.14%。良恶性病灶与周围乳腺腺体组织SWV值比值ROC曲线：AUC为0.902,截断值为1.25,准确性84.80%,敏感性94.44%,特异性78.57%。两组数据ROC曲线下面积比较无统计学意义(P>0.05)。 结论　VTIQ技术对乳腺良恶性结节鉴别有一定诊断价值,无论是剪切波速度还是速度比值均可对临床诊断提供帮助。     

弹性成像联合超声造影定量评估颈动脉低回声斑块与脑梗死再发的关系

目的应用超声弹性成像结合超声造影技术定量分析颈动脉低回声斑块对脑梗死再发的预测价值。方法选取87例临床首次诊断为脑梗死并彩超常规证实有颈动脉低回声斑块的患者,均行超声弹性成像及超声造影,随访一年,分析颈动脉低回声斑块与脑梗死再发的关系。结果 (1)脑梗死再发组Emean、Emax、Emin均低于脑梗死未再发组,而脑梗死再发组PI高于脑梗死未再发组(P<0.05);(2)ROC分析显示,以PI≥20.99 dB且Emax≤21.20 kPa为最佳截断值联合预测脑梗死再发的曲线下面积为0.922(95%CI,0.863~0.982,P<0.001),灵敏度和特异度分别为88.0%、87.0%。结论弹性成像及超声造影技术联合定量评估颈动脉低回声斑块能明显提高脑梗死再发的预测价值。     

声触诊组织成像与定量技术及实时弹性成像技术在甲状腺影像报告与数据系统4类结节的应用价值

目的比较声触诊组织成像与定量技术及实时弹性成像（VTIQ）技术在甲状腺影像报告与数据系统（TI-RADS）4类结节良恶性鉴别诊断中的应用价值。 方法选取2015年11月至2016年3月在浙江大学附属第一医院与浙江金华市中心医院就诊的110例患者（共117个结节）,常规超声检查为TI-RADS 4类甲状腺结节的实时弹性技术成像与声触诊组织成像与定量及VTIQ技术图像特征,实时弹性技术采用测定结节的应变比值（SR）评估结节硬度,VTIQ技术采用测定结节的剪切波速度（SWV）评估结节硬度。以术后病理结果为"金标准",分别计算2种方法单独以及联合应用的敏感度、特异度、准确性、阳性预测值、阴性预测值并绘制受试者工作特征（ROC）曲线,获得曲线下面积（AUC）及最佳临界值。 结果117个甲状腺结节中良性结节43个,恶性结节74个。声触诊组织成像与定量、实时弹性成像技术单独以及联合应用诊断甲状腺癌的敏感度、特异度、准确度、阳性预测值、阴性预测值、ROC曲线下面积分别为80.3% vs 86.7% vs 83.7%,72.5% vs 82.3% vs 84.2%,76.1% vs 84.6% vs 87.5%,73.3% vs 83.4% vs 84.5%,79.7% vs 85.5% vs 88.7%,0.786 vs 0.869 vs 0.881;根据ROC曲线SR的最佳诊断界值为3.3,VTIQ的最佳诊断界值为3.03 m/s。声触诊组织成像与定量与实时弹性成像方法单独以及两者联合应用不同组间曲线面积比较,差异均无统计学意义（Z=1.95、1.83、1.03,P值均>0.05）。 结论声触诊组织成像与定量及VTIQ技术单独或联合应用对诊断甲状腺TI-RADS 4类结节的良恶性均有一定价值,3种方式的诊断价值相当。     

超声弹性成像对干燥综合征不同腺体病变的诊断价值

目的 探讨超声弹性成像对干燥综合征（SS）不同腺体病变的诊断价值。方法 选取我院就诊的75例疑似SS患者，根据欧美专家共识诊断标准（2002年版）将其分为SS患者35例（研究组）和非SS患者40例（对照组），应用超声弹性成像测量两组腮腺和颌下腺剪切波速度（SWV）值，取其平均值为唾液腺SWV值，分析两组间及各组左右侧SWV值的差异。绘制受试者工作特征（ROC）曲线分析超声弹性成像对SS不同腺体病变的诊断效能。结果 研究组腮腺、颌下腺、唾液腺SWV值均高于对照组，差异均有统计学意义（均P<0.05）。对照组和研究组内左右侧腮腺、颌下腺、唾液腺SWV值比较差异均无统计学意义。ROC曲线分析显示，当SWV值为1.94 m/s时，超声弹性成像诊断SS颌下腺病变的曲线下面积（AUC）为0.897，灵敏度为86.4%，特异度为83.0%；当SWV值为2.15 m/s时，超声弹性成像诊断SS腮腺病变的AUC为0.936，灵敏度为93.5%，特异度为86.4%；当SWV值为2.03时，超声弹性成像诊断SS唾液腺病变的AUC为0.959，灵敏度为96.3%，特异度为87.8%。结论 超声弹性成像对...     

声触诊组织成像定量技术联合BI-RADS分类在乳腺病变中的诊断价值

目的探讨声触诊组织成像定量技术（VTIQ）联合乳腺影像报告和数据系统（BI-RADS）分类对乳腺良、恶性病变的诊断价值。 方法回顾性选取2016年8月至2017年4月在哈尔滨医科大学附属第一医院就诊并获得病理结果的172例患者共172个乳腺病变，172例乳腺病变患者均行常规超声检查及BI-RADS分类，并行弹性成像检查，采用VTIQ模式，获得质量模式图及速度模式图，每个病变记录7组剪切波速度（SWV）测值，取平均值。以病理结果为"金标准"，绘制VTIQ、BI-RADS分类方法及VTIQ联合BI-RADS分类方法诊断乳腺良、恶性病变的ROC曲线，计算曲线下面积并确定最佳诊断界值，分析比较3种方法取最佳诊断界值时的诊断效能。并对BI-RADS分类、VTIQ联合BI-RADS分类计算得出的乳腺病变活检率进行比较分析。 结果BI-RADS分类的ROC曲线下面积为0.762，最佳诊断界值为BI-RADS 3与4a类之间；VTIQ（SWV平均值）的ROC曲线下面积为0.895，最佳诊断界值为3.13 m/s；VTIQ联合BI-RADS分类的ROC曲线下面积为0.908，显著高于BI-RADS分类法的0.762（Z=5.79，P<0.01）。由ROC曲线得出VTIQ联合BI-RADS分类法的最佳诊断界值为BI-RADS 4a与4b类之间，其灵敏度、特异度、阳性预测值、阴性预测值和准确性分别为92.9%、88.8%、80.0%、96.3%和90.1%，与BI-RADS分类相比较，其诊断的特异度提高了32.8%，准确性提高了20.9%，阳性预测值提高了28.6%。116例良性病变中，根据BI-RADS分类计算，需要进行活检的为51例（51/116，43.9%）；根据VTIQ联合BI-RADS分类计算，需进一步活检的为16例（16/116，13.8%），活检率较BI-RADS分类法降低，差异有统计学意义（χ²=25.71，P=0.00）。 结论VTIQ技术联合BI-RADS分类对乳腺良、恶性病变具有较好的诊断效能，与BI-RADS分类比较，其有助于提高诊断的特异度及准确性，且可降低良性病变临床活检率，减少不必要的临床干预，可将弹性成像技术作为常规超声BI-RADS分类的有效补充和辅助诊断方法。     

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.