小鼠成骨细胞和破骨细胞共培养模型的建立

目的 建立小鼠成骨细胞和破骨细胞共培养模型,为探讨成骨细胞和破骨细胞之间的相互调控作用奠定基础.方法 利用24 h内新生小鼠颅骨和4～8周龄成年小鼠四肢长骨分别分离、培养成骨细胞和破骨细胞,采用间接接触的培养模式将接种了骨髓单核细胞的玻片或骨片置入提前24 h接种了成骨细胞的培养皿中进行共培养.共培养一定时间后进行破骨细胞抗酒石酸酸性磷酸酶(tartrate-resistant acid phosphatase,TRAP)染色鉴定和骨吸收功能检测,并进一步采用RT-PCR对破骨细胞标志酶基因基质金属蛋白酶.9(MMP-9)、TRAP 和组织蛋白酶K (Cathepsin K ) 的表达进行检测.结果 共培养5天后可见TRAP( )多核细胞形成,13天TRAP( )多核细胞数目达到高峰;骨吸收陷窝在共培养7天后开始出现,随着培养时间的延长,陷窝面积呈增加趋势;破骨细胞标志基因TRAP 在共培养3天时开始表达,而MMP-9和 Cathepsin K则在共培养5天后表达.结论 共培养体系中成骨细胞对破骨细胞调控作用显著,诱导的破骨细胞具有噬骨能力,该共培养模型可用于成骨细胞和破骨细胞之间的相互调控作用研究.     

不同氧环境中破骨细胞的发育分化和功能变化研究

目的 本实验拟观察不同氧浓度下破骨细胞诱导过程中的分化发育,寻找破骨细胞体外培养的适宜氧浓度,为骨转换平衡的修复提供依据.方法 取野生型C57B/L小鼠(2个月龄左右,雄性)骨髓进行破骨细胞的诱导培养.用RANKL(10ng/ml)和M-CSF(10ng/ml)联合的诱导方案,将小鼠骨髓中单核-巨噬细胞系体外诱导为破骨细胞样细胞.将原代破骨细胞置于20%O2、7%O2、2%O2下诱导培养,MOCP5不同氧浓度下普通培养.用MTT法检测MOCP5的增殖变化,用抗酒石酸酸性磷酸酶(TRAP)染色检测破骨细胞形成的变化,并进行TRAP阳性细胞计数,用象牙骨片骨吸收陷窝甲苯胺蓝染色检测破骨细胞骨吸收活性的变化.结果 骨髓中单核-巨噬细胞体外经RANKL和M-CSF联合诱导可分化为多核的破骨细胞样细胞,在诱导第3天细胞开始融合,第5天TRAP染色强阳性,第8天可见象牙骨片上形成圆形、椭圆形、腊肠形等多种形态的骨吸收陷窝.MTT检测显示MOCP5在20%O2培养时一直处于增殖状态,7%O2条件下由增殖期进入平台期,2%O2时增殖缓慢且没有规律.20%O2、7%O2、2%O2培养下形成的TRAP阳性破骨细胞数分别为22±5.97、34±2.97、7±1.39(P<0.05),原代诱导的破骨细胞在20%O2、7%O2、2%O2形成的骨吸收陷窝面积(μm2)分别为3892.28±1642.78、5356.7±1655.6、2573±994.48(P<0.05).结论 体外RANKL和M-CSF联合可将骨髓单核-巨噬细胞诱导成多核的破骨细胞样细胞作为破骨细胞的研究模型.常氧条件下破骨细胞的TRAP阳性细胞数和骨吸收活性均低于7%O2.7%O2培养下的破骨细胞更接近于体内生理状态的破骨细胞.     

血小板衍生生长因子－BB对破骨细胞功能影响的实验研究

目的探讨血小板衍生生长因子 -BB(platelet-derivedgrowthfactor-BB,PDGF -BB)对破骨细胞生物学功能的影响。方法 (1)利用酶消化法分离培养成人破骨细胞 ;(2)应用透射电子显微镜方法观察破骨细胞对PDGF -β 受体的表达 ;(3)在经过纯化的破骨细胞上清液中施加重组人基因PDGF -BB ,利用酶动力学方法测定培养上清液中的酸性磷酸酶 (ACP)和抗酒石酸酸性磷酸酶(TRAP)的活性 ;(4)通过Leica图像分析仪观察在PDGF -BB作用下 ,破骨细胞所形成骨吸收陷窝的数目与面积。结果 (1)破骨细胞膜上有胶体金颗粒沉着 ;(2)破骨细胞培养上清液中的ACP和TRAP活性随着PDGF -BB浓度的升高而增加 ,分别从(1.85±0.13)u/L和(1.73±0.15)u/L(对照组 )增加至(2.86±0.15)u/L和(2.75±0.24)u/L(40μg/L组 ,P<0.01) ;(3)在PDGF -BB的作用下 ,破骨细胞所形成的骨吸收陷窝的面积从(435.08±237.50)μm2(对照组 )增高至(630.26±240.64)μm2 (40μg/L组 ,P<0.01) ,每个骨片上骨吸收陷窝的数目亦从14.00±1.41增加为26.00±2.00(P<0.05或P<0.01)。结论PDGF -BB通过与PDGF -β受体结合 ,可直接促进破骨细胞的骨吸收功能     

巴戟天含药血清对成骨-破骨细胞共育体系CAII、NFAT2mRNA表达的影响

目的 探讨不同浓度巴戟天含药血清对体外培养成骨-破骨细胞共育体系中碳酸酐酶II(CAII)、活化T细胞核因子(NFAT2)mRNA表达的影响。方法 取24h内新生SD乳鼠头盖骨分离培养成骨细胞,取5周龄SD大鼠四肢长骨骨髓基质细胞,加入集落细胞刺激因子(M-CSF)和细胞核因子κB受体活化因子配体(RANKL)诱导培养破骨细胞。采用ALP染色鉴定成骨细胞,TRAP染色、骨吸收陷窝甲苯胺蓝染色、电镜等扫描鉴定破骨细胞,体外建立成骨-破骨细胞共育体系,设置高、中、低3种浓度巴戟天含药血清组和对照组,干预3d后提取各组总RNA,应用Real Time PCR(RT-PCR)方法测定各组CAII、NFAT2mRNA表达并进行统计学分析。结果 不同浓度巴戟天含药大鼠血清对成骨-破骨细胞共育体系CAII、NFAT2mRNA的表达均有抑制作用,且其抑制作用表现出一定的浓度依赖性;各组间差异有统计学意义(P＜0.05)。结论 巴戟天含药血清可抑制成骨-破骨细胞共育体系CAII、NFAT2mRNA表达,从而达到降低破骨细胞分化成熟及骨吸收活性。     

共培养体系中重组结核杆菌热休克蛋白10对破骨细胞相关基因表达的影响（R68)

目的观察重组结核杆菌热休克蛋白10(CPN10)对成骨细胞(OB)-外周血单个核细胞(PBMs)共培养体系中破骨细胞生成及相关基因表达的影响。方法建立培养上清相通但二者互相不接触的成骨细胞一单个核细胞共育模型。实验分对照组和CPN10(10μg/ml)处理组。主要观察指标:①采用TRAP染色及扫描电镜检测破骨细胞生成及小牛骨磨片吸收陷窝,②应用Realtime PCR检测与破骨细胞生成相关基因NFATc1、c-Fos、RANKL、OPG的基因表达。结果两组细胞均有TRAP阳性多核破骨细胞生成,并在小牛骨磨片上形成吸收陷窝;但对照组所获TRAP阳性多核细胞数目、吸收陷窝数目及面积均显著小于CPN10组。Realtime PCR检测结果显示CPN10组与对照组相比NFATc1、c-Fos、RANKL、OPG相对浓度分别为7.410±1.738、8.844±1.981、22.4272±2.058、2.445±0.2517(P0.05),对照组各基因表达均显著低于CPN10组。结论 CPN10在成骨细胞-单个核细胞(OB-PBMs)共培养体系中可促进OC的生成及骨吸收,CPN10通过对成骨细胞的作用,致其分泌的OPG/RANKL比例失调,并上调破骨细胞相关基因NFATc1、c-Fos、RANKL、OPG的基因表达。     

骨水泥颗粒促进肿瘤坏死因子α诱导的破骨细胞形成及其骨吸收作用

目的:验证骨水泥颗粒对肿瘤坏死因子α(TNFα)诱导的破骨细胞形成及其生物学活性的影响。方法:体外培养外周血单核细胞,对照组加入TNFα和白细胞介素-1α(IL-1α)及巨噬细胞克隆集落刺激因子(M-CSF),实验组并分别加入含有或不含有硫酸钙的骨水泥(PMMA±BaSO4)颗粒。对培养终末细胞作组织化学染色检测破骨细胞标志物抗酒石酸酸性磷酸酶(TRAP)的表达,并以象牙磨片上虫蚀样骨吸收陷窝的形成为指标检测破骨细胞的生物学活性;并比较各实验组中TRAP阳性多核细胞(multinucleatedcells,MNCs)及虫蚀样骨吸收陷窝形成时间的早晚。结果:各组TRAP阳性MNCs的数量无明显差异;PMMA±BaSO4组象牙磨片上骨吸收陷窝的面积均较对照组大,差异具有显著性(P<0.01);并且PMMA±BaSO4组TRAP阳性的MNCs及虫蚀样骨吸收陷窝的形成均较对照组早。结论:PMMA±BaSO4颗粒能够促进TNFα诱导的破骨细胞分化提早发生并促进其骨吸收活性。     

Transwell小室内建立小鼠成骨-破骨细胞共培养体系

目的 :Transwell小室内建立体外小鼠成骨-破骨细胞共培养体系,并检测体系对成骨及破骨细胞活性的影响。方法:体外培育小鼠成骨细胞MC3T3-E1和小鼠单核巨噬细胞RAW264.7,RANKL诱导小鼠单核巨噬细胞RAW264.7分化为成熟破骨细胞后,于Transwell小室内建立成骨-破骨细胞共培养体系。通过CCK-8实验、茜素红染色、TRAP染色检测细胞的成骨、破骨活性。采用PCR、Western Blot方法检测成骨细胞MC3T3-E1中OPG、ALP、RANKL、TGF-b1的基因表达以及RANKL的蛋白表达,检测破骨细胞RANK、NF-κB的基因表达和蛋白表达。结果 :小鼠成骨细胞MC3T3-E1和小鼠破骨细胞可在Transwell小室内建立共培养体系;共培养体系影响小鼠成骨细胞与破骨细胞的分化活性,镜下可见成骨细胞分化增多,破骨细胞分化稍减少。共培养体系中成骨细胞基因OPG(0.65±0.08)、ALP(0.16±0.01)较单独培养OPG(1.00±0.08)、ALP(1.01±0.16)表达下降,而TGF-b1(4.42±0.21)、RANKL(4.12±1.04)较单独培养组TGF-b1(1.00±0.10)、RANKL(1.00±0.09)表达上升;破骨细胞相关RANK(0.63±0.06)、NF-κB(0.64±0.08)基因表达较单独培养组的RANK(1.00±0.08)、NF-κB(1.00±0.09)下降,差异均有统计学意义。同时共培养组的OPG(0.43±0.05)、NF-κB(0.59±0.05)的蛋白表达较单独培养组的OPG(0.84±0.06)、NF-κb(1.13±0.03)减少;共培养组RANKL(0.54±0.03)的蛋白表达则较单独培养组的RANKL(0.31±0.03)增加,差异有统计学意义,均与基因表达变化趋势一致。结论:小鼠成骨细胞MC3T3-E1和小鼠破骨细胞可在Transwell小室内建立共培养体系,共培养体系中成骨细胞活性高于破骨细胞活性。     

建立成骨与破骨细胞共育体系的一种方法

目的：建立成骨细胞和破骨细胞共育的体外模型，为研究骨生理和病理提供新的方法。方法：从胎鼠和4周鼠中分离成骨和破骨细胞，并按照10：1、100：1的比例混合培养，应用碱性磷酸酶(AKP)、抗酒石酸(TRAP)、甲苯胺蓝染色法，鉴定成骨及破骨细胞，并测量碱性磷酸酶的含量，从而建立一个较稳定的共育体系。结果：破骨细胞和成骨细胞达到了相互接触培养，且随着破骨细胞数量的不同，碱性磷酸酶的含量会有不同的变化。结论：该模型可用骨形成和吸收代谢的相关研究。     

应用颅骨-破骨细胞联合培养体系研究先天性成骨不全破骨细胞骨吸收活性

目的 先天性成骨不全(OI)的主要临床表现为骨矿化过程不良,骨量丢失,骨骼畸形和骨折.但是其发病机理,尤其在其骨再建过程中成骨细胞(OB)及破骨细胞(OC)的功能改变尚不清楚.本实验以先天性成骨不全小鼠模型,oim/oim为基础,应用破骨细胞-颅骨联合培养体系研究OB和OC两种细胞在骨再建过程中的功能改变和相互作用.方法 本实验采用小鼠颅骨(CAL)组织培养模型.本模型采用颅骨组织培养,利用颅骨中成骨细胞可以从颅骨片游离出到培养皿及颅骨表面,从而支持培养皿及颅骨表面前体破骨细胞分化成为成熟破骨细胞,并吸收颅骨产生吸收陷窝.本实验中,共2组颅骨-破骨细胞联合培养体系:(1) 对照组(WT)颅骨与对照破骨细胞(WTCAL-WTOC);(2) OI颅骨与OI破骨细胞(OICAL-OIOC).联合培养颅骨及骨髓组织14日后,以TRAP免疫组化染色方法识别破骨细胞,ALP免疫组化染色方法识别成骨细胞,计算OC/OB.破骨细胞骨吸收活性以颅骨表面骨吸收陷窝占颅骨表面百分比并除以培养系统中的破骨细胞数表达.结果 第14日,OICAL-OIOC组的破骨细胞数低于WTCAL-WTOC组(92.50+23.18/mm2 对比 379.00+ 136.53/mm2,P<0.01); OICAL-OIOC组的OC/OB明显低于WTCAL-WTOC组(0.68+0.57对比1.65+0.67,P<0.01);OICAL-OIOC组OI破骨细胞的吸收能力高于WTCAL-WTOC组(27.76+22.81对比7.32+5.09,P<0.001).结论 oim/oim小鼠破骨细胞-颅骨培养体系中破骨细胞的数目明显减少,成骨细胞支持破骨细胞分化能力减低;但其破骨细胞骨吸收活性明显增强,以代偿成骨细胞功能,维持骨再建过程中成骨过程及骨吸收过程的平衡.     

阿司匹林对大鼠破骨细胞分化成熟和骨吸收活性的影响

目的 研究不同浓度阿司匹林对体外培养大鼠破骨细胞(Osteoclast,OC)分化成熟及骨吸收活性的影响.方法 建立由核激活因子受体配体(receptor activator of NF-κB ligand,RANKL)和巨噬细胞集落刺激因子(Macrophage colony stimulating factor,M-CSF)共同作用的大鼠破骨细胞骨髓诱导体系,将雌激素(10-6 mmol/L)和不同浓度的阿司匹林(0.25 mmol/L、0.5 mmol/L、1.0 mmol/L、1.5 mmol/L)分别作用于破骨细胞.诱导培养后分别对破骨细胞进行抗酒石酸酸性磷酸酶(The tartrate-resistant acid phosphatase,TRAP)染色,观察细胞形态,并计数破骨样细胞数量;将各组破骨细胞接种于骨磨片上,建立破骨细胞-骨磨片活性分析模型,于不同时间点对骨磨片进行光镜和扫描电镜观察,分析计算骨吸收陷窝面积.结果 与正常对照组相比,雌激素组破骨细胞数量和骨吸收陷窝面积低于正常对照组,差异有统计学意义(P＜0.05);且随着阿司匹林浓度的增加,阿司匹林组TRAP阳性多核破骨细胞数量、骨吸收陷窝面积逐渐减少直至消失,差异有统计学意义(P＜0.05).与雌激素组相比,低浓度阿司匹林组(0.25mmol/L)没有明显差异;但中、高浓度阿司匹林实验组(0.5mmol/L、1.0mmol/L、1.5mmol/L)破骨细胞数量和骨吸收陷窝面积减少,差异有统计学意义(P＜0.05).结论 阿司匹林对破骨细胞的分化成熟及骨吸收功能有抑制作用,且呈剂量依赖性,从而具有抗骨质疏松的作用.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

The multiply injured child

Blunt trauma is the principal cause of childhood death in many developed countries. This review outlines the differences between adults and children with respect to resuscitation and treatment of orthopaedic injuries in a child with polytrauma. Recent advances in techniques of fracture stabilization are reported.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.     

Utilisation des médicaments prokinétiques en réanimation : indications et limites ?

Enteral feeding is often limited by gastric and intestinal motility disturbances in critically ill patients, particularly in patients with shock. So, promotility agents are frequently used to improve tolerance to enteral nutrition. This review summaries the pathophysiology, presents the available pharmacological strategies, the clinical data, the counter-indications and the principal limits. The clinical data are poor. No study demonstrates a positive effect on clinical outcomes. Metoclopramide and erythromycin seems to be the more effective. Considering the risk of antibiotic resistance, the first line use of erythromycin should be avoided in favor of metoclopramide.