珊瑚颈椎椎间融合器与钛螺纹状椎体融合器(TFC)的近期临床疗效观察

目的探索珊瑚颈椎椎间融合器与螺纹状椎体融合器(TFC)临床应用的特点和早期治疗效果,观察两种融合器植入后的颈椎的稳定性和植入节段的活动度。方法11例脊髓型颈椎病患者(17个节段)行颈前路椎体间隙减压,6例(11个节段)行珊瑚颈椎间融合器融合术,5例(7个节段)行钛螺纹状椎体融合器(TFC)融合术。手术前后采用JOA标准对颈段脊髓功能进行评分,术后1周、1月摄颈椎前后位片。观察颈椎的稳定性和植入节段的活动度。结果11例例患者均症状明显缓解、脊髓功能改善,其中优(改善率>75%)7例,良(改善率50～74%)2例.中(改善率25～49%)1例,无效(改善率<25%)0例。JOA评分由术前平均7.4分上升至术后13.4分。两组术后1周、1月置换节段稳定,没有偏移和下沉,无异常活动融合牢固。结论采用珊瑚椎间融合器及钛螺纹状椎体融合器(TFC)的椎间融合术早期均能保持颈前路减压的良好效果,同时维持了颈椎的融合稳定度。但颈椎椎间融合器是否能减少对临近节段的影响及其长期的稳定性和脊髓功能的评定尚需临床长期随访,珊瑚颈椎椎间融合术为脊髓型颈椎病的治疗提供了一种新的选择。     

斜向单枚BAK植入后路腰椎椎体间融合术的生物力学及临床研究

目的 :对作者设计的单枚融合器后斜向植入后路腰椎椎体间融合术行生物力学评价及临床观察。方法 :生物力学研究 :12个小牛脊柱运动节段分为 2组 ,每组 6个。实验组行单侧小关节突、半椎板切除术 ,经侧后方斜向植入加长BAK融合器 1枚 ;对照组行常规后路双侧小关节突、全椎板切除术 ,后前向植入双枚融合器。分别测试两组的纵向压缩、屈曲、侧方弯曲、伸展及双向扭转刚度并进行比较。临床研究 :经后路斜向植入单枚融合器行腰椎椎体间融合术共 40例 ,平均随访 18个月 ,进行临床评价。结果 :生物力学研究显示实验组的垂直压缩刚度、左侧 (融合器植入侧 )弯曲刚度、双侧扭转刚度均较双枚融合器组增大 (P <0 0 5 )。临床随访结果显示 ,患者症状缓解率为 92 % ,术后 1年融合率 88% ,主观满意率 90 % ,所有患者均无融合器的移位。结论 :经侧后方斜向植入单枚融合器的腰椎椎体间融合术 ,能满足后路椎体间融合的生物力学要求 ,有损伤小、脊柱后柱稳定性好、可同时行椎管减压等优点 ,可以较理想地取代后路双枚融合器植入的腰椎椎体间融合术     

颈椎终板结构的生物力学研究

目的 研究颈椎终板不同位点生物力学特性的分布规律。方法 运用人体新鲜颈椎标本66椎，对终板平面上的20个特定测试点进行压缩试验，用直径2mm的半球形压头以0.03mm/s的速度垂直终板平面下压2mm，由所得的压缩力-位移线计算最大压缩力及刚度，采用析因分析对实验数据进行统计处理。结果 （1）颈椎各节段之间最大压缩力及刚度的差异有显著性（P＜0.01)，且由上而下呈逐渐减小趋势。终板矢状方向中各点之间最大压缩力及刚度的差异有显著性（P＜0.01），且椎体后部是最大压缩力及刚度较大的区域；终板冠状方向上各点之间最大的压缩力及刚度（除下终板最大压缩力外）的差异均无显著性（P＞0.05)。（2）下颈椎相邻终板之间的最大压缩力及刚度的差异有显著性（P＜0.05），下终板的最大压缩力及刚度比上终板大。矢状方向上相邻板的最大压缩力差异有显著性（P＜0.05）。结论 颈椎上终板后都、下终板后外侧区是椎体力学强度最大的区域。在进行颈前路融合术时下颈椎较易发生塌陷，且塌陷多发生于颈椎上终板平面。     

自制颈椎融合器的实验研究

目的　探讨自制颈椎融合器在动物体内的应用 ,为进一步临床应用提供实验依据。方法　应用实验动物山羊 2 0头 ,分为实验组和对照组 ,分别测试抗压缩力、椎间隙高度及组织反应。结果　 (1)抗压缩力 :自制颈椎融合器 (3 5 8.64± 15 .63 )N ,自体骨植入组为 (2 68.82± 11.3 6)N ,差异有显著性 (P <0 .0 5 ) ;(2 )椎间高度 :自制颈椎融合器组为 (12 .0 5± 0 .16)mm ,自体髂骨植入组为 (12 .0 5± 0 .14 )mm ,差异无显著性 (P >0 .0 5 ) ;(3 )自制颈椎融合器有较好的生物相容性。结论　自制颈椎融合器强度大、生物相容性好、稳定性好 ,是一种比较理想的颈椎融合器。     

颈椎钩椎关节融合器初始稳定性生物力学测试

目的测试颈椎钩椎关节融合器的初始稳定性。方法将20具山羊颈椎标本随机分为完整颈椎组、自体髂骨块植入组、钩椎关节融合器植入组、传统椎间融合器植入组四组,采用非破坏弹性法对山羊C_(3～4)节段进行过伸/过屈、左右侧屈以及轴向旋转活动范围(range of motion,ROM)测试。结果钩椎关节融合器组、零切迹融合器对照组在前屈、后伸、左右侧屈、轴向旋转维度上角位移与髂骨块植入组均差异有统计学意义(P0.05);钩椎关节融合器组和零切迹融合器对照组过伸/过屈ROM差异无统计学意义(P0.05),但钩椎关节融合器组左右侧屈ROM和左右旋转ROM略小于零切迹融合器对照组,差异有统计学意义(P0.05)。结论钩椎关节融合器在左右侧屈与轴向旋转方面稳定性略优于传统零切迹椎间融合器,在前屈/后伸方面与传统零切迹椎间融合器稳定性相当。     

不同终板准备方法对ProDisc-C颈椎人工椎间盘假体稳定性的影响

目的:探讨不同颈椎终板准备方法对颈椎人工椎间盘置换术后金属-骨界面刚度的影响,了解终板准备方法与人工椎间盘假体稳定性的关系。方法:取6具新鲜成人尸体颈椎标本,分离出C3～T1共35个椎体(1例C6～C7融合),剔除每个椎体上下面的椎间盘组织,显露出骨性终板,分为:去终板组17个,完全去除骨性终板;保留终板组18个,完整保留骨性终板。在所有椎体的上面安放相应大小的颈椎人工椎间盘(ProDisc-C)后用MTS-858生物力学实验机进行疲劳测试和屈服测试,得到金属-骨界面的刚度、位移和最大屈服压力,从其中1具颈椎标本取出4个椎体(每组各2个)切片行HE染色后用光镜观察金属-骨性界面。结果:疲劳前测试金属-骨界面刚度去终板组为1470±180N/mm,高于保留终板组的1260±170N/mm(P<0.0001);疲劳后测试两组刚度均有上升,去终板组刚度为1990±110N/mm,仍高于保留终板组的1680±140N/mm(P<0.0001)。疲劳前测试两组的终板位移分别为0.45±0.09mm和0.41±0.10mm,无显著性差异(P=0.15),疲劳后测试去终板组位移0.53±0.12mm小于保留终板组的0.66±0.14mm(P=0.005)。去终板组最大屈服压力为1110±350N,略小于保留终板组的1250±230N,但无显著性差异(P=0.27)。组织切片显示去终板组金属-骨界面贴合良好,而保留终板组金属-骨界面有明显的缝隙。结论:不同的终板准备方法会影响到假体金属-骨界面的刚度和稳定性。去终板组金属-骨界面的刚度和稳定性优于保留终板组,良好的金属-骨界面接触是颈椎人工椎间盘假体稳定的关键因素之一。     

椎体间融合术中植骨材料的研究进展

正脊柱生理弯曲的存在导致脊柱不仅受到垂直压力,还会受到剪切和旋转应力的影响,手术后维持脊柱的稳定性仅靠内固定很难达到,椎体间融合可以有效地分担内固定负荷,防止内固定松动、断裂~([1-2])。最初的手术只能在椎体间植入骨组织来促进椎体间稳定。融合器的发明促进了椎体间融合的发展,先后出现了钛制螺纹旋入式椎间融合器、高分子聚合材料(聚醚醚酮)椎间融合器、可吸收椎间融合器、多孔钛合金材料融合器~([3-4])以及最新研     

高分子聚乙烯颈椎融合器的生物力学特性研究

目的探讨不同颈椎融合器椎间融合后对颈椎稳定性的影响以及椎间融合的生物力学特性.方法采集12具新鲜尸体颈椎标本,制作成3种颈椎融合标本,应用实验应力分析方法对颈椎进行稳定性分析.结果3种颈椎融合材料的生物力学特性正常组与自制融合器组差异无显著性(P>0.05);同种异体髂骨块组与自制融合器组的生物特性试验结果差异有显著性(P<0.05);自制融合器与Bagby＆Kuslich椎间融合器(BAK)组的结果差异无显著性(P>0.05).结论自制颈椎融合器强度大、刚度高、下沉移位小、颈椎稳定好,是一种比较理想的椎间融合器.     

颈椎间不同植入物固定后稳定性的比较

目的：比较颈前路减压后分别植入异体骨螺纹晤支架、肽合金融合支架和自体髂骨对椎间稳定性的影响。方法：用８具人尸体颈椎为空白模型,环锯减压后,分别植入异体骨螺纹融合支架、钛合金螺纹融合支架和自体髂骨,测试以上状态下标本的应变和位移结果：减压后标本较空白对照应变和位移增加,异体现有螺纹融合支架、钛合金螺纹融合支架固定能减少这种增加,而自体髂骨只能减少总体位移增加。结论：Ｃｌｏｗａｒｄ术减压后,颈椎稳定下     

TFC技术在颈前路手术的应用

本文报告螺纹状多孔融合器(TFC)新技术用于颈前路减压椎间融合术治疗颈椎伤病共11例.作者认为颈前路减压后椎体间采用TFC技术,具有固定牢靠、椎间撑开、可恢复或保持椎间盘高度,损伤小、恢复快等优点.     

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.     

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.     

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.     

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.     

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.     

Anesthésie générale chez l’enfant : quid des pratiques en 2010 ?

Introduction

The practice of pediatric anesthesia requires a regular update of scientific knowledge and technical skills. To provide the most adequate Continuing Medical Education programs, it is necessary to assess the practices of pediatric anesthesiologists. Thus, the objective of this survey was to draw a picture of the current clinical practices of general anesthesia in children, in France.

Material and methods

One thousand one hundred and fifty questionnaires were given to anesthesiologists involved in pediatric cases. These questionnaires collected information on various aspects of clinical practice relative to induction, maintenance, recovery from general anaesthesia and also classical debated points such as children with Upper Respiratory Infection (URI), emergence agitation, epileptoid signs or anaesthetic management of adenoidectomy. Differences in practices between CHG (general hospital), CHU (teaching hospital), LIBERAL (private) and PSPH (semi-private) hospitals were investigated.

Results

There were 1025 questionnaires completed. Fifty-five percent of responders worked in public hospitals (CHG and CHU); 77% had a practice that was 25% or less of pediatric cases. In children from 3 to 10 years: 72% of respondents used always premedication and two thirds performed inhalation induction in more than 50% of cases. For induction, 53% used sevoflurane (SEVO) at 7 or 8%. Respondents from LIBERAL used higher SEVO concentrations. Tracheal intubation was performed with SEVO alone (37%), SEVO and propofol (55%) and SEVO with myorelaxant (8%), 93% of respondents used a bolus of opioid. For maintenance, the majority of respondents used SEVO associated with sufentanil; desflurane and remifentanil were more frequently used in CHU. Two thirds of respondents used N₂O. Depth of anesthesia was commonly assessed by hemodynamic changes (52%), end tidal concentration of halogenated (38%) or automated devices based on EEG (7%). In children with URI, 98% of respondents used SEVO for anesthesia. To control the airway 42% used a tracheal tube, 30% a laryngeal mask and 20% a facial mask. Emergence agitation was an important concern for two thirds of respondents, while epileptoid signs were considered as important by only 20%. Eighty-nine percent of respondents practiced anesthesia for adenoidectomy. Anesthesia was induced by inhalation of SEVO 7–8% (41%), 6% (39%) or 4% (12%), 66% put an intravenous line (less frequently in LIBERAL). 67% of the responders managed adenoidectomy without any device to control the airway (more frequently in LIBERAL), 32% administrated a bolus of opioid (less frequently in LIBERAL).

Discussion

This survey demonstrated that the practices regarding general anesthesia in children are relatively homogenous. Most of the differences appeared between LIBERAL and the others structures; the anaesthetic management for adenoidectomy illustrates these findings.     

Intérêt d’une rééducation précoce pour les patients neurologiques

Rehabilitation improves the functional prognosis of patients after a neurologic lesion, and tendency is to begin rehabilitation as soon as possible. This review focuses on the interest and the feasibility of very early rehabilitation, initiated from critical care units. It is necessary to precisely assess patients’ impairments and disabilities in order to define rehabilitation objectives. Valid and simple tools must support this evaluation. Rehabilitation will be directed to preventing decubitus complications and active rehabilitation. The sooner rehabilitation is started; the better functional prognosis seems to be.