葛根素预处理对离体大鼠心肌缺血再灌注损伤的保护作用

目的通过建立大鼠离体心脏缺血再灌注模型,探讨葛根素预处理对大鼠心肌缺血再灌注损伤的保护作用及其可能机制。方法在langendǒrff离体心脏体外灌注模型复制基础上,采用随机对照方法将50只雄性SD大鼠平均分为5组:对照组、缺血再灌注组、缺血预处理组、小剂量葛根素预处理组、大剂量葛根素预处理组,记录每只大鼠平衡灌注15 min、再灌注153、0 min的心功能变化,包括心率(HR)、左室最高压(LVSP)、左室舒张末压(LVEDP)、左室压力升高速率(+dp/dtmax)、左室压力降低速率(-dp/dtmax)。并于平衡灌注15 min、复灌1、3、5、10、15、30 min测定冠脉流出液中肌酸激酶(CK)的含量。测定心肌丙二醛(MDA)、超氧化物歧化酶(SOD)、一氧化氮(NO)的含量,并作电镜检查。结果缺血再灌注组可引起HR、LVSP、+dp/dtmax、-dp/dtmax下降,LVEDP升高以及CK释放增加,心肌MDA产生增多、SOD及NO含量降低,与对照组相比有显著性差异。缺血预处理组及葛根素预处理组均能显著改善缺血再灌注引起的心功能损伤,降低CK的释放,减少心肌组织MDA的生成,并增加心肌组织中SOD和NO含量,减轻心肌细胞超微结构的病理改变。大剂量葛根素预处理组比小剂量葛根素预处理组对上述指标的改善更为显著。结论葛根素预处理能减少脂质过氧化,明显改善心功能,提高心肌组织对后续缺血的耐受性。这种保护作用存在量效关系,其产生与心肌中SOD增高减轻了氧自由基损伤和NO增高扩张冠脉有关。     

缺血预处理对高血脂大鼠心肌再灌注损伤和氧自由基代谢的影响

目的研究缺血预处理 (IP)对缺血再灌注 (I/R)高血脂大鼠离体心脏功能、心肌酶、氧自由基的影响。方法采用大鼠离体心脏灌注模型 ,以左室收缩峰压 (LVSP)和心室内瞬间最大变化速率 (dp/dtmax)估价心功能。以心肌酶 (CK)反应心肌损伤 ,以心肌组织丙二醛 (MDA)含量、超氧化物歧化酶 (SOD)活性、心肌细胞线粒体中谷胱甘肽过氧化酶 (GRH PX)活性反映心肌自由基代谢。将IP和I/R情况进行比较。结果IP使高血脂大鼠心脏再灌注后LVSP、dp/dtmax增高、CK降低、MDA减少、SOD和GSH PX增高 (均P <0 .0 5 ) ,且与正常大鼠无显著性差异 (均P >0 .0 5 )。结论IP对高血脂大鼠心肌缺血再灌注损伤有保护作用。高血脂可能不参与心肌缺血再灌注损伤的机制。     

1,6-二磷酸果糖预处理对离体大鼠心肌缺血再灌注损伤的影响

目的探讨1,6-二磷酸果糖(FDP)预处理对大鼠离体心肌缺血再灌注损伤的保护作用。方法应用Langendorff离体心脏灌注系统制备离体大鼠心脏全心缺血再灌注模型。雄性SD大鼠16只,随机分为2组,每组8只:缺血再灌注组(I/R组)和1,6-二磷酸果糖预处理组(FPC组),所有心脏予以缺血30 min,再灌注60 min。FPC组在持续缺血前用含FDP的K-H液灌注15 min做预处理。记录各组心脏在平衡30 min(T0)、缺血30 min(T1)、再灌注5 min(T2)、再灌注15 min(T3)、再灌注30 min(T4)、再灌注60 min(T5)时的左心室发展压(LVDP)和左心室压力最大上升速率(+dp/dtmax)、左心室舒张末压(LVEDP)和左心室压力最大下降速率(-dp/dtmax)、左心室收缩压(LVSP)、左心室舒张压(LVDP)、心率(HR)、冠状动脉流量(CF),并计算(LVSP-LVDP)3心率。实验结束后取心肌组织用比色法测定其中的超氧化物歧化酶(SOD)和丙二醛(MDA)的含量;常规石蜡固定切片,以免疫组化法测定Bcl-2和Bax的表达及以TUNEL法检测凋亡指数。结果与I/R组相比,FPC组的LVDP、(LVSP-LVDP)3HR、CF在T3~5时点、+dp/dtmax在T2~5时点、HR在T4~5时点升高显著(P<0.05,P<0.01),而LVEDP在T2~5时点降低显著(P<0.05,P<0.01),表明FPC组的心功能显著优于I/R组,且FPC组心肌中的SOD增加而MDA减少、Bcl-2升高而Bax降低、心肌凋亡指数也显著下降。结论 FDP预处理可明显改善大鼠离体缺血再灌注的心功能和减少氧自由基的生成及其对质膜的脂质过氧化作用而保护心肌。     

姜黄素对大鼠心肌缺血再灌注损伤的心肌保护作用

目的探讨姜黄素对SD大鼠心肌缺血再灌注损伤的心肌保护作用及机制。方法 2018年3月选取SD大鼠80只,随机分为4组,A组为假手术大鼠,B组进行心肌缺血再灌注,C组在缺血后,再灌注6 h前1 min内舌下静脉推注姜黄素(20 mg/kg),D组在缺血后,再灌注6 h前1 min内舌下静脉推注姜黄素(20 mg/kg)和锌原卟啉Ⅸ(Zn PPⅨ)(7. 5 mg/kg)。观察各组SD大鼠缺血再灌注后心功能[包括:心率(HR)、左心室舒张压(LVDP)、左心室内压最大上升速率(+dp/dtmax)、左心室内压最大下降速率(-dp/dtmax)]和心肌组织病理改变。比较各组大鼠心肌组织HO-1酶活性及蛋白表达;比较各组大鼠心肌组织肌酸激酶(CK)、乳酸脱氢酶(LDH)、天门冬氨酸氨基转移酶(AST)、丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和游离脂肪酸(FFA)水平。结果各组大鼠缺血再灌注后心功能:B组LVDP、+dp/dtmax、-dp/dtmax较A组显著下降,差异具有统计学意义(P 0. 05),C组LVDP、+dp/dtmax、-dp/dtmax较B组显著升高(P 0. 05),D组以上指标低于C组(P 0. 05)。心肌组织病理改变:C组较B组心肌细胞变性坏死程度轻,较A组重。D组心肌损伤程度较C组加重。心肌组织HO-1酶活性及蛋白表达:C组HO-1酶活性明显高于B组,D组较C组低(P 0. 05)。C组较B组HO-1蛋白表达上调,D组抑制了HO-1蛋白表达(P 0. 05)。B组大鼠心肌组织CK、AST、LDH、MDA、FFA水平明显高于A组(P 0. 05),SOD、GSH-Px水平明显低于A组(P 0. 05); C组大鼠心肌组织中CK、AST、LDH、MDA、FFA水平较B组显著下降(P 0. 05),SOD、GSH-Px水平较B组显著升高(P 0. 05); D组大鼠心肌组织中CK、AST、LDH水平较C组升高,SOD、GSH-Px水平较C组显著下降,差异均具有统计学意义(P 0. 05)。结论姜黄素对大鼠心肌缺血再灌注损伤具有心肌保护作用,可能通过上调HO-1蛋白活性和表达而减轻心肌缺血再灌注损伤。     

ω-3脂肪酸后处理保护大鼠心肌缺血-再灌注损伤的血流动力学及形态学研究

目的 观察ω-3脂肪酸后处理对大鼠离体心肌缺血-再灌注损伤的保护作用,并探讨其可能的机制.方法 SD大鼠40只,随机分为4组:持续灌注组(Con组)、缺血-再灌注组(I-R组)、缺血后处理组(Post组)和ω-3脂肪酸后处理组(Post-ω组).Con组持续灌注150 min,其余各组均平衡灌注30 min,全心缺血30 min,再灌注90 min,Post组在再灌注开始前进行4个循环的复灌20 s/缺血20 s,Post-ω组在再灌注开始前用ω-3脂肪酸灌注15 min.记录平衡灌注末及再灌注30、60、90 min时左室舒张末压(LVEDP)、左室发展压(LVDP)、左室内压上升最大速率(+dp/dtmax)、左室内压下降最大速率(-dp/dtmax)、心率(HR).复灌结束后,TTC染色计算心肌梗死面积,透射电镜下观察心肌线粒体形态结构的改变.结果 与I-R组比较,Post-ω组可显著增加复灌30、60、90 min +dp/dtmax (P＜0.01)和-dp/dtmax(P＜0.05).与I-R组比较,Post、Post-ω组心肌梗死面积显著缩小(P＜0.05).与I-R组比较,Post组、Post-ω组大鼠心肌线粒体损伤程度减轻.结论 ω-3脂肪酸后处理可提高离体大鼠心肌舒缩力,可能通过减少心肌梗死面积以及减轻心肌细胞线粒体损伤改善离体大鼠心肌缺血-再灌注损伤.     

缺血预适应对离体高血脂大鼠缺血再灌注损伤的影响

目的:通过建立缺血预适应(IP)模型,探讨IP对离体高血脂大鼠缺血再灌注(I/R)损伤的保护作用。方法:通过喂食高脂造型饲料建立高血脂大鼠模型,随机分成正常组和高血脂组,实验过程中每组再分为对照组、IP组、I/R组,测定各组的LVSP、dp/dtmax、ATPase、MDA、SOD、冠脉流出液的CK值。结果:经缺血预处理后明显减轻缺血再灌注损伤,与I/R组比较,正常大鼠和高血脂大鼠的CK减少22%和27%,MDA降低26%和20%,SOD升高12%和17%,ATPase升高41%和46%,LVSP升高35%和37%。结论:缺血预适应对离体高血脂大鼠缺血再灌注损伤同样有保护作用,保护程度与正常大鼠接近。     

硫酸锌联合阿司匹林治疗急性心肌梗死大鼠的效果及其作用机制

【目的】探讨硫酸锌联合阿司匹林治疗急性心肌梗死(AMI)大鼠的效果及其作用机制。【方法】选取健康成年SD雄性大鼠,随机分为假手术组(未建模,生理盐水灌胃)、模型组(建立AMI模型,生理盐水灌胃)、硫酸锌组[建立AMI模型,硫酸锌75 mg/(kg·d)灌胃]、阿蚜匹林组[建立AMI模型,阿司匹林75 mg/(kg·d)灌胃]、联合组[建立AMI模型,硫酸锌与阿司匹林(2:1)120 mg/(kg·d)灌胃],连续处理7 d。检测并比较各组大鼠乳酸脱氢酶(LDH)、肌酸激酶(CK)、天门冬氨酸氨基转移酶(AST)、丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、左室内压最大上升速率(+dp/dtmax)、左室内压最大下降速率(-dp/dtmax)、心室开始收缩至发生dp/dtmax的间隔时间(t-dp/dtmax)、左室舒张末期压(LVEDP)、左室收缩压(LVSP)、心肌梗死面积比(MIS%)等值,观察各组心肌组织结构变化。【结果】模型组大鼠血清LDH、CK、AST水平显著高于假手术组,联合组大鼠血清LDH、CK、AST水平显著的低于模型组、硫酸锌组、阿司匹林组,其差异均有统计学意义(P<0.05)。模型组大鼠血清MDA水平显著高于假手术组,血清SOD及GSH-Px显著低于假手术组,其差异均有统计学意义(P<0.05);联合组大鼠血清MDA水平体于模型组、硫酸锌组、阿司匹林组,联合组大鼠血清SOD及GSH-Px高于模型组、硫酸锌组、阿司匹林组,其差异均有统计学意义(P<0.05)。模型组大鼠+dp/dtmax、-dp/dtmax、LVSP测定值显著低于假手术组(P<0.05),联合组的+dp/dtmax、-dp/dtmax、LVSP测定值显著高于模型组、硫酸锌组、阿司匹林组,其差异均有统计学意义(P相似文献   

心肌缺血再灌注损伤中肿瘤坏死因子α血清水平表达对心肌收缩功能影响的实验研究

目的探讨心肌缺血再灌注损伤中肿瘤坏死因子α(TNF-α)血清水平表达对心肌收缩功能的影响。方法用健康的雄性Sprague Dawley(SD)大鼠造心肌缺血再灌注损伤模型。连接BioLab-410型生物信号采集和处理系统,记录心电图,测定并记录心肌缺血前、缺血30 min及再灌注30 min、60 min、90 min、120 min各个时相点血清中TNF-α水平和血流动力学指标;通过多普勒超声,得到各时相点左心室舒张末期内径(LVIDd)、左心室收缩末期内径(LVIDs)值,然后按照Teichholtz公式计算出左心室射血分数(LVEF),再分析TNF-α水平与心肌功能相关性。结果冠状动脉结扎后30 min,大鼠血清中TNF-α较缺血前明显增高,差异具有统计学意义(P<0.05)。再灌注后较缺血前、缺血30 min显著增加,差异具有统计学意义(P<0.05),再灌注后维持在较高水平;冠状动脉结扎30 min后,平均动脉血压(MAP)、心率(HR)、左心室收缩压(LVSP)、+dp/dtmax、-dp/dtmax明显降低,左心室舒张末压(LVEDP)明显增高,LVIDd、LVIDs明显上升,与缺血前差异具有统计学意义(P<0.05);再灌注后比缺血前MAP、HR、LVSP、+dp/dtmax、-dp/dtmax显著降低,LEVDP显著增高,LVIDd、LVIDs明显上升,差异具有统计学意义(P<0.05);再灌注后比缺血30 min时MAP、HR、LVSP、+dp/dtmax、-dp/dtmax明显下降,LEVDP明显上升,LVIDd、LVIDs明显上升,差异具有统计学意义(P<0.05)。结论心肌缺血再灌注损伤中血清TNF-α水平的表达与心肌收缩功能出现平行的同向变化趋势,呈明显负相关,TNF-α血清水平升高会抑制心肌收缩功能,影响心脏功能。     

阿魏酸对正常大鼠离体心脏缺血／再灌注损伤的影响

目的：探讨阿魏酸对大鼠离体心脏缺血／再灌注损伤的影响。方法：42只SD大鼠随机分为3大组，包括：正常对照（Con）组、缺血／再灌注损伤（I／R）组、、阿魏酸缺血／再灌注损伤组（FA）。采用离体大鼠心脏Langendorff逆行灌注模型，观察阿魏酸用药前后HR（心率）、LVSP（左心室收缩压）、dp/dtmax（左心室内压最大上升速率）、t-dp／dtmax（左心室开始收缩至dp／dtmax的间隔时间）等心功能指标的变化。结果：FA组相对于I／R组，可明显改善心脏的收缩功能，有统计学意义。结论：阿魏酸可以改善正常离体大鼠心脏的缺血／再灌注损伤。     

葛根素对大鼠肝脏缺血再灌注损伤的抗氧化作用及对部分生化指标的影响

目的探讨葛根素对大鼠缺血再灌注损伤肝脏的抗氧化作用及对部分生化指标的影响。方法建立大鼠全肝缺血再灌注模型，60只大鼠随机分为三组，每组20只，分别为假手术对照组（A组）、肝缺血／再灌注组（B组）和肝缺血／再灌注加葛根素治疗组（C组），分剐在肝缺血前、缺血45min、再灌注45min共3个时相点，检测血浆超氧化物歧化酶（SOD）活性、黄嘌呤氧化酶（XO）活性、丙二醛（MDA）浓度以及血清谷丙转氨酶（ALT）活性。结果肝缺血／再灌注组，血浆XO，MDA及ALT显著高于假手术对照组、SOD明显低于假手术对照组（P〈0．05或Y〈0．01）；而葛根素治疗组与缺血／再灌注组比较，上述指标均有显著性差异（P〈0．05或P〈0．01）。结论葛根素可通过降低氧自由基水平（增强SOD活性、减弱XO活性）拮抗脂质过氧化反应（降低MDA浓度），从而减轻肝脏缺血再灌注损伤。     

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.