影响回路内麻醉气体吸附器效果多因素分析

目的：研究XF—9801型活性炭吸附器对异氟醚吸入麻醉的吸附效果的影响因素。方法：20例择期手术病人,术中根据手术需要调整蒸发器刻度维持异氟醚呼气末浓度0.6～1.0MAC,记录病人的麻醉持续时间和呼气末异氟醚浓度,手术结束,使用回路内吸附器后,达到呼气末异氟醚浓度0.2%和0.3%所持续的时间,将该时间与麻醉持续时间、呼气末异氟醚浓度、体重、年龄进行逐步回归分析。结果：回路内吸附器使用后,达到呼气末异氟醚浓度0.2%和0.3%所持续的时间分别为8.0±2.3min和2.5±1.2min,而且该时间与呼气末异氟醚浓度、体重、麻醉持续时间和年龄呈现明显的相关性(P＜0.05)。病人的苏醒时间为12.3±4.5min。结论：回路内吸附器使用后,呼气末异氟醚浓度0.2%和0.3%所持续的时间分别与呼气末异氟醚浓度、体重、麻醉持续时间和年龄呈现明显的相关性。使用回路内活性炭吸附器后病人的苏醒时间明显缩短。     

吸烟对异氟醚吸入麻醉时无机氟代谢的影响

目的:无机氟通过异氟醚代谢而释放,血浆氟离子浓度提高可能损害肾功能。吸烟者可能诱导或者抑制药物代谢,本文研究吸烟和药物代谢之间的相互关系以及可能的毒性。方法:17例非吸烟病人和17例吸烟病人择期行手术,ASA分级为Ⅰ-Ⅱ级,在空气和氧气混合的情况下,给与标准的吸入麻醉药异氟醚1MAC*h,测量血浆无机氟离子24h和肾功能标记物β2-微球蛋白,肿瘤相关胰蛋白酶抑制因子(TATI)和血肌酐48h。结果:非吸烟病人最大的氟离子浓度7.2-23.0(12.8±4.0μmol/L),吸烟病人最大的氟离子浓度7.6-39.0(16.8±6.7μmol/L),平均差值为4.0μmol/L(p<0.05),血β2-微球蛋白,肿瘤相关胰蛋白酶抑制因子(TATI)和肌酐没有提高。血无机氟离子浓度在1MAC*h异氟醚吸入1、2、3和6h。两组之间比较有显著差异(P<0.05),吸入麻醉24h两组病人元机氟离子浓度仍然高于基础水平。48h观察过程中,尿β2-微球蛋白,肿瘤相关胰蛋白酶抑制因子和肌酐比值始终处于低水平。结论:吸烟患者在异氟醚吸入麻醉之后与血浆无机氟离子浓度增高有关系,但是并没有肾功能损害的现象。     

Genistein在调节肝癌HepG2细胞Fas基因表达及诱导细胞凋亡中的作用

目的: 探讨三磷酸肌醇( IP3) 和Fas基因表达变化在genistein诱导肝癌细胞凋亡中的作用。方法:以肝癌HepG2 细胞培养72h为对照,以20,40.60,80μmol/ L genistein作用于 HepG2 细胞72h和60μmol/L genistein 作用于 HepG2 细胞6h、12 h、24 h、48 h、72 h，应用同位素试剂盒IP3 - [3H] Birtrak检测细胞IP3 含量，RT-PCR分析Fas mRNA表达，Western blotting 分析细胞Fas蛋白表达，流式细胞仪检测细胞凋亡率。结果: 各浓度的genistein作用于肝癌HepG2 细胞72 h，IP3 含量显著高于对照组[（17.7±1.3）pmol/106cells、（11.2±0.9）pmol/106cells、（4.9±0.5）pmol/106cells、（4.8±0.3）pmol/106cells vs （29.4±0.5）pmol/106cells]，Fas mRNA表达显著高于对照组[RI（灰度与面积之积与β-actin的相对强度）0.25±0.002、0.30±0.01、0.28±0.04、0.30±0.03 vs 0.19±0.01]，Fas蛋白表达显著高于对照组[RI1.08±0.01、 1.11±0.02、1.05±0.06、1.03±0.01 vs 0.17±0.01]，细胞凋亡率显著高于对照组[（10.1±0.9）%、（18.7±1.6）%、（28.7±2.5）%、（27.9±2.0）% vs （2.6±0.1）%]；60 μmol/L genistein 作用于肝癌HepG2 细胞6h、12 h、24 h、48 h、72 h，6h后IP3 含量显著高于对照组[（22.6±0.9）pmol/ 106cells、 (12.0±1.4) pmol/ 106cells、(7.5 ±0.8) pmol/ 106cells、(5.6 ±0.5) pmol/ 106cells、(4.3 ±0.6) pmol/ 106cells vs (29.2 ±0.6) pmol/ 106cells。P < 0.01）；12h后Fas mRNA表达显著高于对照组[RI0.24±0.01、0.24±0.01、0.24±0.02、0.30±0.001 vs 0.20±0.01]，6h后Fas蛋白表达显著高于对照组[RI 0.55±0.08、 1.01±0.03、1.62±0.03、1.46±0.09 、1.56±0.04 vs 0.18±0.01]，24 h后各时相细胞凋亡率为显著高于对照组[(7.4 ±0.5) %、(20.5 ±2.0) %、(30.7 ±1.6) % vs (2.6 ±0.1) %。P < 0.01]。结论: Genistein能减少IP3 生成,上调Fas基因表达,诱导肝癌细胞凋亡。     

异氟醚预处理延迟相对兔心肌缺血再灌注损伤的保护作用

目的探讨不同浓度异氟醚预处理延迟相对兔心肌缺血再灌注损伤的影响。方法30只健康新西兰雄性大白兔随机分成三组:1组:缺血再灌注组,行冠状动脉左前降支阻断40 min,再灌注120 min;2组:1.0%异氟醚预处理组,予以1.0%异氟醚 100%氧气持续吸入2 h后停止吸入异氟醚,于24 h后同1组处理;3组:2.0%异氟醚预处理组,予以2.0%异氟醚 100%氧气持续吸入2 h后停止吸入异氟醚,于24 h后同2组处理。各组分别于左冠前降支阻断前20 min(T1)、左冠前降支阻断20 min(T2)、左冠前降支阻断40 min(T3)、心肌再灌注1 h(T4)心肌再灌注2 h(T5)五个时点取颈内动脉血测定肌钙蛋白(cTnI)浓度。再灌注结束后观察心肌超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及心肌细胞超微结构的变化。用伊文思蓝和TTC染色法测心梗面积,同时观察心肌细胞超微结构变化。结果①2组和3组肌钙蛋白增高程度低于1组(P<0.05)。②心肌梗死面积:2组(24.2%±2.1%)和3组(19.7%±2.8%)低于1组(37.8%±1.7%)(P<0.05)。③心肌细胞电镜观察显示预处理组心肌细胞损伤轻于对照组。④2组和3组MDA较1组降低(P<0.05),SOD较1组增高(P<0.05)。结论异氟醚预处理延迟相对兔心肌缺血再灌注损伤有保护作用。     

异氟醚抑制Notch-1通路诱导小鼠神经干细胞凋亡

目的:探讨异氟醚对小鼠神经干细胞的影响及其可能的机制。方法:分离小鼠神经干细胞并培养,分为对照组、磷酸盐缓冲液(PBS)组和异氟醚组。对照组无任何干预,异氟醚组给予异氟醚,PBS组给予等量的PBS,培养24 h。采用CCK-8法检测细胞增殖率;实时定量–聚合酶链反应法检测凋亡相关基因的mRNA水平;蛋白质印迹法检测凋亡相关蛋白的表达;Annexin V-FITC/PI法检测细胞凋亡。结果:与对照组和PBS组比较,异氟醚组细胞增殖率明显降低,同时Notch-1、CBF-1、Hes-1基因的mRNA及相应蛋白表达水平也显著下降。异氟醚组细胞凋亡数目与对照组、PBS组比较,差异有统计学意义。结论:异氟醚能够诱导小鼠神经干细胞的凋亡,此作用与Notch-1信号通路的抑制密切相关。     

芦荟大黄素对增生性瘢痕成纤维细胞凋亡的量效影响

目的:观察天然药物芦荟大黄素对增生性瘢痕成纤维细胞凋亡的作用。方法:实验于2001-06/2004-12在广东医学院整形外科研究所完成。成纤维细胞取自广东医学院附属医院整形外科患者手术切除的增生性瘢痕组织,瘢痕组织经处理后进行成纤维细胞原代及传代培养至第3～8代细胞。用剂量为40mg/L的芦荟大黄素分别处理对数生长期成纤维细胞[0(为对照组),24,48,72h],以流式细胞术检测细胞周期和细胞凋亡率;观察加入不同浓度(0,20,40,60,80mg/L)芦荟大黄素后24h对成纤维细胞凋亡的影响,采用特异性荧光染色和原位末端标记技术分别检测凋亡指数。结果:①芦荟大黄素作用不同时间对成纤维细胞周期和凋亡的影响:流式细胞术检测发现,用药24h出现“亚二倍体峰”即凋亡峰,凋亡指数为(10.81±1.43)%,到48和72h凋亡指数为(16.02±1.30)%和(21.58±1.56)%。随着作用时间的延长,DNA合成前期细胞百分数增多,DNA合成期的细胞含量逐渐减少,亚二倍体峰百分数增多(F=122.514,225.552,105.346,P<0.05)。②芦荟大黄素对成纤维细胞凋亡的量效影响:荧光染色和原位末端标记法检测凋亡指数,均呈剂量依赖性增高[荧光染色:0mg/L为(4.52±1.22)%,20mg/L为(25.56±1.12)%,40mg/L为(56.20±2.20)%,80mg/L为(80.05±2.12)%,F=1350.737;原位末端标记法:0mg/L为(3.85±1.15)%,20mg/L为(11.66±1.20)%,40mg/L为(23.12±1.06)%,80mg/L为(40.31±1.43)%,F=511.487,P<0.01]。结论:芦荟大黄素以时间依赖性的方式调节细胞周期并诱导增生性瘢痕成纤维细胞凋亡,还可呈量效关系促进成纤维细胞发生凋亡。     

实验性大鼠急性脑缺血细胞凋亡与相关蛋白表达的关系

目的:研究大鼠脑缺血再灌注后细胞凋亡及p53,Bcl-2蛋白家族表达的变化,并探讨它们在细胞凋亡中的作用。方法:实验在华北煤炭医学院形态实验室完成。54只大鼠用随机数字表法随机分成3组:脑缺血组(42只)、假手术组(6只)和正常组(6只)。脑缺血组又分为7组:即缺血2h再灌注1,3,6,12,24,48和72h组(n=6)。采用线栓法制作局灶性脑缺血再灌注模型,用TUNEL法检测细胞凋亡的变化,用免疫组化法检测p53,Bcl-2和Bax蛋白的表达水平。结果:①缺血2h再灌注1h皮质区可见凋亡细胞[(7.83±1.72)个/高倍视野],24～48h达高峰[(43.33±5.20)个/高倍视野,(48.50±6.25)个/高倍视野],72h开始下降[(26.67±3.56)个/高倍视野](P<0.05,P<0.01);缺血2h再灌注1h皮质区可见p53蛋白阳性细胞[(14.35±1.92)个/高倍视野],24h达高峰[(48.00±6.42)个/高倍视野],48h后开始下降[(31.00±6.60)个/高倍视野](P<0.05,P<0.01);缺血2h再灌注1h皮质区可见Bcl-2蛋白阳性细胞[(28.62±6.80)个/高倍视野],3h达高峰[(56.50±7.87)个/高倍视野],6h后开始下降[(45.00±6.63)个/高倍视野](P<0.01);缺血2h再灌注1h皮质区可见Bax蛋白阳性细胞[(45.83±4.07)个/高倍视野],24h达高峰[(61.00±8.88)个/高倍视野],48h开始逐渐下降[(45.83±6.49)个/高倍视野](P<0.     

氟马西尼对异氟醚残余麻醉作用的拮抗作用

目的:探讨氟马西尼是否可以拮抗异氟醚的麻醉残余作用,加速麻醉苏醒。方法:采用随机、双盲、对照方法,选择择期手术、年龄18～60岁、ASA分级Ⅰ～Ⅱ级且无术前用药患者60例,芬太尼3μg/kg、丙泊酚2mg/kg、维库溴胺0.1mg/kg诱导,异氟醚、芬太尼、维库溴胺维持麻醉。手术结束停止异氟醚的吸入,继续机械通气,当呼气末异氟醚浓度降至0.45%～0.5%时,分为3组,分别给予生理盐水(对照组)、氟马西尼0.5mg(0.5mg组)和氟马西尼1.0mg(1.0mg组)。每间隔1分钟进行1次意识评价,至患者定向力恢复。记录呼之睁眼、指令运动、正确回答问题、定向力恢复的时间,以及血压、脉搏、脑电双频指数(BIS)值、体温、呼气末异氟醚浓度、呼气末二氧化碳值。并在手术诱导前,定向力恢复时,定向力恢复后15、30、60、120min分别给患者出示一张不同的图片,术后24h随访患者对图片的记忆情况。结果:患者的一般情况差异无显著性(P>0.05)。对照组、0.5mg组和1.0mg组患者从停止吸入异氟醚至指令运动恢复时间分别为(19.58±6.91)min、(22.05±9.19)min和(20.32±6.44)min(P...     

异氟醚预处理联合参附注射液对大鼠短暂性局灶性脑缺血损伤协同保护作用的研究

目的探讨异氟醚预处理联合参附注射液对短暂性局灶性脑缺血性损伤的协同性保护作用.方法40只雄性SD大鼠,随机分为4组,每组各10只.对照组即单纯缺血再灌注组;参附注射液保护组(参附组)在缺血前30分钟经腹腔注射参附注射液10ml/kg;异氟醚预处理组(异氟组)动物每日接受1小时的异氟醚预处理(2%异氟醚,98%氧气),连续5日;异氟醚预处理联合参附注射液保护组(异参组)动物同时接受异氟醚预处理和参附注射液腹腔注射.用右侧颈内动脉线栓法致鼠大脑中动脉阻闭120分钟,拔出尼龙线为再灌注时间.观察再灌注后24小时的神经功能损害改变及评分,24小时后处死动物,取大脑行2%TTC染色以测量脑梗死容积.结果24小时神经功能损害评分在参附组、异氟组和异参组分别为(0.9±0.7)分、(0.8±0.6)分和(0.6±0.5)分,均明显低于对照组(1.9±0.6)分(P均<0.05),各处理组间神经功能损害评分无显著性差异.脑梗死容积对照组为(172.5±46.3)mm3,参附组为(75.5±36.7)mm3,异氟组为(59.1±29.5)mm3,异参组为(30.6±24.8)mm3,各处理组梗死容积均明显小于对照组(P均<0.05);异参组梗死容积明显小于异氟组及参附组(P均<0.05),后2组间无显著性差异.结论异氟醚预处理联合参附注射液对短暂性局灶性脑缺血损伤具有一定的协同保护作用.     

KATP通道参与介导吸入麻醉药诱导的兔在体心肌预适应

目的探讨KATP通道在吸入麻醉药异氟醚、七氟醚和地氟醚所诱导的心肌预适应中的作用.方法64只新西兰白兔随机分成8组缺血-再灌注组(IR),异氟醚预处理组(IP),七氟醚预处理组(SP),地氟醚预处理组(DP),异氟醚预处理+优降糖组(IP+G),七氟醚预处理+优降糖组(SP+G),地氟醚预处理+优降糖组(DP+G),优降糖组(G).每组均接受左冠脉前降支3小时阻断和3小时再灌注.吸入药预处理组在缺血前分别吸入1.1%异氟醚、2%七氟醚、6%地氟醚30分钟后,洗脱15分钟,加用优降糖组在吸入麻醉药前或相当时间静脉注入优降糖0.33mg/kg.结果心肌梗死面积占缺血面积的比IR组为0.61±0.11,IP、SP、DP组分别减少至0.39±0.06、0.31±0.07和0.32±0.08,与IR组相比均有显著差异(P均<0.05);IP+G、SP+G、DP+G组分别是0.64±0.12,0.57±0.12和0.62±0.11,与IR组相比均无显著差异(P均>0.05);G组并不增加梗死面积(1.17±0.32)g,梗死面积占缺血面积比为0.63±0.13,与IR组相比无显著差异(P>0.05).结论异氟醚、七氟醚、地氟醚预处理产生的心肌保护作用与激活KATP通道有关.     

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.