骨密度对椎弓根螺钉系统固定的影响之生物力学研究

目的：探讨骨密度（ＢＭＤ）对椎弓根螺钉系统固定的影响。方法：采用６具新鲜腰段脊柱标本，应用ＤＥＸＡ测试每个椎体的ＢＭＤ，并游离成单个完整椎体标本，按ＢＭＤ０．９ｇ／ｃｍ２为正常值的最低限。将标本分为正常组和骨质疏松组。按标准操作安置Ｄｉｃｋ钉，应用生物力学方法，测试螺钉最大轴向拔出力和矢状面摆动１°～５°时的弯矩、旋入螺钉时的最大扭力矩及螺钉拔出过程中的应变、位移和能量吸收率。结果：正常组平均ＢＭＤ为１．０２±０．１２ｇ／ｃｍ２，骨质疏松组为０．７１±０．１６ｇ／ｃｍ２，前者最大轴向拔出力和弯矩分别为１０６２．８±７２．２Ｎ、２．６Ｎ·ｍ，后者为２３２±９２．４Ｎ、０．４９Ｎ·ｍ。ＢＭＤ与最大拔出力有正相关关系（ｒ＝０．９０７）。旋入螺钉时的最大扭力矩与轴向拔出力密切相关（ｒ＝０．８９４）。螺钉在椎体内摆动５°时正常组承受的最大弯矩为２．６Ｎ·ｍ，骨质疏松组为０．４９Ｎ·ｍ。结论：ＢＭＤ对椎弓根螺钉的稳定性具有重要影响，是预测螺钉牢固程度的重要指标，术前应常规测试脊柱的ＢＭＤ，尤其对于老年人更为重要，最大扭力矩是术中预测螺钉稳定性的一个较好的力学指标。     

经椎弓根内固定的形态与生物力学研究

目的：提高临床医师对椎弓根内固定技术的理论认识。方法：应用直径４．５ｍｍ,５．５ｍｍ,６．２５ｍｍ和７．０ｍｍ４种不同直径的椎弓根螺钉１６具Ｔ６～Ｓ１节段的新鲜尸体脊柱标本上观察：（１）穿钉失败率;（２）椎弓根膨胀变形率;（３）椎弓根螺钉把持力;（４）椎弓根椎体损伤分类。结果：穿钉失败率与操作技术和椎弓根横径相关,在下胸椎失败率高主要与椎弓根横径密切相关,没有发生穿钉失败的椎弓根膨胀率２８．６％～     

膨胀式脊柱内固定系统椎弓根螺钉翻修作用的生物力学研究

目的：评价自行设计的膨胀式脊柱同定系统（expansive spinal fixation system，ESFS）的椎弓根螺钉对椎弓根螺钉固定失败后的翻修作用。方法：将30个深低温冰冻的正常成人腰椎体标本随机分为A、B、C三组．每组10个椎体（20侧椎弓根）。各组标本每个椎体的两侧椎弓根均先拧入直径6．0mm、长45mm的CD-Ⅱ螺钉．行螺钉拔出试验，记录螺钉的最大旋入力矩和最大轴向拔出力。然后将CD-Ⅱ螺钉拔出，各组标本每一椎体随机经一侧椎弓根原钉道拧入直径7．0mm、长45mm的ESFS螺钉；A组另一侧椎弓根拧入直径7．0mm、长45mm的CD-Ⅱ螺钉，B组另一侧拧入直径7．0mm、长45mm的TSRH螺钉．C组另一侧拧入直径7．0mm、长45mm的GSS螺钉。分别测试螺钉最大旋入力矩和最大轴向拔出力。结果：A、B、C三组的ESFS螺钉最大轴向拔出力分别为6mm CD-Ⅱ螺钉的113％、110％和112％，而直径7．0mm、长45mm的CD-Ⅱ螺钉、TSRH螺钉和GSS螺钉的最大轴向拔出力分别只有6mm CD-Ⅱ螺钉的80％、82％和88％，各组ESFS螺钉最大轴向拔出力明显高于其它三种螺钉。差异有显著性（P〈0．01）。各组各螺钉最大旋入力矩之间差异无显著性（P〉0．05）。结论：ESFS螺钉具有很好的椎弓根锚固作用及翻修作用。     

100例国人腰椎弓根的CT测量及其临床意义

对１００例国人腰椎弓根进行了ＣＴ形态学测量。结果表明腰椎弓根厚度从Ｌ１～Ｌ５呈递增趋势，Ｌ１～Ｌ５椎弓很平均厚度分别是５．３、 ６．７、９．５、１１．５和１４．７ｍｍ。椎弓根轴线与椎体棘突中央矢状面夹角（倾斜角），从Ｌ１～Ｌ５亦呈递增趋势，Ｌ１～Ｌ５各椎弓根平均倾斜角分别为１５．９７、１５．９１、１９．１９、２２．７８和２８．４７度。本文亦对椎弓根厚度与椎弓根螺钉的直径及进钉倾斜角进行了探讨，并提出在Ｌ４～Ｌ５节段应使用直径７．０ｍｍ的椎弓根螺钉。     

钛合金及不锈钢椎弓根螺钉的骨—螺钉界面力学及组织学分析

目的 从组织学和力学上比较钛合金和不锈钢椎弓根螺钉的骨－螺钉界面的区别。方法：１８只成年微型猪随机平均分为两组,分别接受Ｌ４．５椎板切除,Ｌ４．５钛合金和不锈钢椎纽根螺钉内固定手术。两种装置都是ＣＣＤ类型,螺钉具有相同的形状和大小。术后观察３个月。Ｌ４的两个螺钉连同椎弓根一起取下进行组织计量学研究。Ｌ５的两个螺钉维持原位不动,进行力学测试。力学测试包括螺钉的扭转试验和拔出试验。结果 螺钉扭转试验表     

椎弓根螺钉把持椎弓根皮质骨对其固定强度的影响

目的：了解椎弓根螺钉把持椎弓根皮质骨对椎弓根螺钉固定强度的影响。方法：将成年羊腰椎椎弓根48个依据椎弓根皮质骨内径和椎弓根螺钉直径（6．25mm）的相对关系分为三组：A组，螺钉直径小于椎弓根皮质骨内径：B组．螺钉直径超出椎弓根皮质骨内径0.01～0．50mm；C组，螺钉直径超出椎弓根皮质骨内径0.51～1．00mm。每组再根据进钉深度与椎弓根长度（平均约8mm）的相对关系分为Ⅰ（进钉深度为16mm）、Ⅱ（进钉深度为8mm）两组。将椎弓根螺钉置入椎弓根中，观察钉道结构、膨胀情况，测量椎弓根螺钉最大轴向拔出力。结果：椎弓根螺钉置入后，椎弓根发生不同程度膨胀；椎弓根螺纹能够切入皮质骨中；C Ⅰ组最大轴向拔出力比A Ⅰ组和B Ⅰ组大（P〈0．05），C Ⅱ组最大轴向拔出力比A Ⅱ组和B Ⅱ组大（P〈0．05），B Ⅱ组比A Ⅱ组大（P〈0.05）。结论：椎弓根螺钉把持椎弓根皮质骨能够增加椎弓根螺钉的固定强度；且椎弓根螺钉把持椎弓根皮质骨量越大，固定强度越大。     

肝动脉栓塞加手术切除治疗大肝癌37例

作者报告３７例大肝癌采用肝动脉栓塞（ＴＡＥ）加手术切除的疗效及临床病理研究结果。３７例肝癌直径５～２４ｃｍ（平均１１．２Ｃｍ）。ＴＡＥ与动脉灌注化疗同时进行。化疗药物括氟尿嘧啶（５－ＦＵ）、阿霉素（ＡＤＭ）或表阿霉素（Ｅ－ＡＤＭ）、丝裂霉素（ＭＭＣ）和顺铂（ＣＤＤＰ）。多采用三种药物联合方案。肝动脉末梢栓塞剂采用国产或进口碘化油，用明胶海绵颗粒作近端栓塞。手术切除前进行１～４次ＴＡＥ，每次相隔４～６周。１７例ＡＦＰ值增高者ＴＡＥ后１０例降至正常水平。肿瘤直径由平均１１．２ｃｍ降至８．５ｃｍ（缩小２６％）。栓塞后手术切除病理标本显示９２％有肿瘤组织坏死，范围达４０％～１００％。１、２、３年生存率分别为８０％、６６．７％和５３．３％。作者认为ＴＡＥ加手术切除是大肝癌的有效治疗方法。     

氯胺酮对大鼠脑内cAMP信使系统的影响

本研究旨在动态观察氯胺酮对大鼠不同脑区３’,５－环腺昔酸（ｃＡＭＰ）含量、腺苷酸环化酶（ＡＣ）活性及磷酸二酯酶（ＰＤＥ）活性的影响,探讨氯胺酮麻醉与ｃＡＭＰ信使系统的相关性。材料和方法 药品和试剂：盐酸氯胺酮为江苏省连云港制药厂生产,批号为９８０３１１。ＡＴＰ、蛇毒、腺苷、ＱＡＥ．Ｓｅｐｈａｄｅｘ Ａ－２５为 ｓｉｇｍａ公司产品。３Ｈ－ｃＡＭＰ和ｃＣＡＭＰ测定试剂盒由中国原子能研究院同位素研究所提供。动物及分组 ＳＤ（Ｓｐｒａｇｕｅ Ｄａｗｌｅｙ）大鼠 ３２只,雌雄不限,体重２００～３００ｇ,随机各分…     

肿瘤浸润性淋巴细胞结合偶联半乳糖抗CD3单抗趋肝性初探

目的 探讨结合偶联半乳糖（Ｇａｌ）的大鼠抗小鼠ＣＤ３单克隆抗体（Ｍｏｕｓｅ－ａｎｔｉ－ｒａｔ－ＣＤ３ｍｏｎｏｃｌｏｎａｌ ａｎｔｉｂｏｄｙ Ａｎｔｉ－ＣＤ３－ＭｃＡｂ）肿瘤浸润性淋巴细胞的（ＴＩＬ）趋肝性，方法 本实验把小鼠抗小鼠ＣＤ３单克隆缺本和半乳糖（Ｇａｌ）偶联在一起，与＾３Ｈ－ＴｄＲ标记ＴＩＬ结合后，从尾静脉注入小鼠体内，分别在注射后不同时间抠眼取血０．５ｍｌ，然后处死，切除肝、脾、肺组织     

胶体金标记法测定烧伤性休克时外周血单核白细胞表面LFA-1的表达

研究证明,白细胞粘附于细静脉壁和嵌塞毛细血管是重症休克微循环灌流量不易恢复的重要原因［１］。并证明多形核粒细胞（Ｐｏｌｙｍｏｒｐｈｏｎｕｃｌｅａｒｌｅｕｋｏｃｙｔｅｓ,ＰＭＮｓ）粘附性的升高在缺血和再灌注后的血管组织损伤中起着重要的作用。ＰＭＮｓ对内皮细胞的粘附由ＰＭＮｓ表面的ＣＤ１８粘附受体复合物［包括ＬＦＡ１（ＬｙｍｐｈｏｃｙｔｅＦｕｎｃｔｉｏｎＡｓｓｏｃｉａｔｅｄＡｎｔｉｇｅｎ１,ＣＤ１１ａ／ＣＤ１８,淋巴细胞功能相关抗原１）、Ｍａｃ１（Ｍａｃｒｏｐｈａｇｅ１,ＣＤ１１ｂ／ＣＤ…     

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.     

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.     

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.     

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.