多发伤病人机械通气时营养支持

目的 :探讨营养支持在治疗并发有重度肺功能障碍的多发伤病人过程中的作用。方法 :2 5例多发伤病人在实施机械通气过程中予以营养支持 ,并检测营养支持前后的营养指标 ,其中 19例早期采用全胃肠外营养 ( TPN)支持 ,6例采用肠内营养 ( EN)。结果 :痊愈 16例 ,4例转手术科室 ,3例死亡 ,2例持续植物状态。 16例痊愈者营养支持前后血红蛋白、白蛋白、血清总蛋白、转铁蛋白、氮平衡均有显著提高 ( P<0 .0 5)。结论 :合理的营养支持有助于控制多发伤病人因高代谢状态导致的营养和免疫衰竭 ,合并严重肺功能障碍而实施机械通气者平稳脱机 ,并降低死亡率及致残率。     

肠外营养对机械通气患者撤机的意义研究

目的：探讨肠外营养（PN）支持对ICU内机械通气危重患者脱机的意义。方法：268例因各种病因致呼吸衰竭的危重患者,在机械通气撤机期间给予胃肠外营养支持治疗,并与124例撤机训练期间未行肠外营养支持治疗的机械通气患者进行比较。结果：与对照组相比,肠外营养支持组营养支持后有关营养状况的指标明显改善,负氮平衡减轻（P＜0．05）。撤离呼吸机的呼吸力学指标明显改善,呼吸机参数条件降低（P＜0．05）,该组脱机平均所需时间明显短于对照组,一次性脱机成功率显著高于对照组（P＜0．05）。结论：肠外营养支持有助于增强呼吸肌的质量和功能,有利于早期脱机。     

双门经颅多普勒检测机械心瓣膜患者微栓子信号的研究

目的 :研究脑动脉微栓子信号 (MES)的基本特征。方法 :采用双门深经颅多普勒 (TCD)检测了 2 1例机械心瓣膜患者的脑动脉 MES。结果 :MES阳性发现率为 80 .95 % (17/ 2 1) ,MES出现频率为 0～ 40 4(中位数 40 )个 /小时 ,MES相对强度为11～ 38(2 3.6 3± 5 .13) d B。84.89%的 MES在二个取样深度依次显示 ,时间延迟为 0 .4～ 2 8.4(中位数 6 .0 ) m s,15 .11% MES仅见于近端通道 ,而在远端通道未能显示。结论 :双门深 TCD是研究 MES基本特征的有效方法     

When is the right time to take an emergency surgery decision in Mechanical Intestinal Obstruction?

Background/Objective: Ischemia is a leading cause of morbidity in Mechanical Intestinal Obstruction (MIO) in which the timing of decisions of whether to proceed to surgical or conservative treatment is critical in emergency departments (ED). While advanced technological options are available, patients may be negatively affected by the application of contrast agents or radiation. The use of ultrasound is limited because of the air in the intestines does not allow a good field of vision. While biomarkers can be considered as a good alternative option at this point. In the present study we examine the effect of hemogram and blood gas parameters on early surgical decision-making in MIO patients.MethodInvolved in this observational prospective study were 264 patients diagnosed with MIO who presented to the Department of Emergency Medicine, Ataturk Research and Training Hospital, Katip Celebi University between February 2018 and February 2019. Contrast-enhanced tomography (CECT) and laboratory results of the patients were recorded. Pathology reports of the patients who underwent surgery were collected. Laboratory data were analyzed by comparing CECT and pathology reports.ResultsIn a ROC analysis of the laboratory values of the patients who were diagnosed with ileus, the sensitivity was calculated as 80% and the specificity was 57.7 in values above WBC>10.75 (10⁹/L), 96.6%, and the specificity was 31.1% in N/L > 2.9. For intestinal ischemia, the cut-off values were WBC> 12.6 and N/L > 3.2, Lactate >2.8 mmol/L and B.E < -3.6 mmol/L.ConclusionDiagnoses of ileus are based on the results examinations and imaging methods. More data are needed to support decisions on the timing of surgery in ED. WBC, N/L, Lactate and Base Excess indicate an ischemic segment. When the parameters are evaluated together, they strongly support early surgical decision-making regarding the treatment of intestinal ischemia.     

电阻抗断层成像技术用于呼气末正压滴定的研究进展

适当的呼气末正压（PEEP）是保护性肺通气策略的重要组成部分,PEEP可以保持肺泡开放,减少肺萎陷伤。尽管个体化PEEP已被越来越多的临床医师认可,但最佳的PEEP滴定方法尚存争议。电阻抗断层成像（EIT）是一种无创、无辐射的成像技术,可在床边实时动态评估肺功能,将肺通气过程中的阻抗变化以动态图像呈现,能够反映PEEP调整前后肺内通气及气体分布变化,因此,EIT可用于滴定个体化PEEP。本文简要概括EIT的基本原理及监测指标,阐述临床应用EIT指导下的PEEP（PEEPEIT）滴定方法,旨在加强对EIT的优点和局限性的理解,为优化个体化PEEP的设置提供参考。     

A physicomathematical approach to the structure of the mandible

Summary Classical methods of anatomical study and experimentation have reached an endpoint with respect to the advancement of our knowledge of certain aspects of bone, i.e. its mechanical properties, investigation of the constraints acting on bone and the organization of bone allowing resistance to such mechanical stress. Indeed, current knowledge is rather limited regarding bone as a material. Furthermore, bone from the cadaver cannot be considered a reliable source of study material since its physicochemical composition and mechanical properties are highly different from those of living bone. The types of experimentation used to date, although allowing to study the phenomena occuring on the surface of the bone, do not allow to evaluate those that occur within the bone without modification of its mechanical features. Finally, the number and complexity of the parameters to be taken into account in this respect largely supersede the possibilities of classical study techniques.Accordingly, new types of methodology are required to evaluate the many parameters involved, to perform the corresponding computations and resolve the great number of unknown variables. Such methodology must allow experimentation to be performed without modifying the object of study and to determine the phenomena occuring within the bone itself, i.e. the mandible.A method of computer assisted simulation of a physicomathematical model was used to analyse the structural properties of the mandible. This method was based on that used for the computation and elaboration of large metal structures (offshore drilling platforms), structures submitted to special stress (resistance to force 7 earthquake of the new extension to the radioactive waste disposal factory at the Hague) or aeronautical structures composed of composite material.

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Approche physico-mathématique structurale de la mandibule

Résumé L'étude des propriétés mécaniques de l'os, celle des contraintes qu'il subit, la manière dont il est organisé pour résister à ces contraintes s'avèrent déboucher sur une impasse si l'on se contente des méthodes classiques d'études et d'expérimentations.En effet, nous n'avons actuellement qu'une connaissance très limitée de l'os en qualité de matériau. Le matériau d'expérimentation, l'os de cadavre ne peut être considéré comme fiable, sa constitution physico-chimique et ses propriétés étant par trop différentes de celles de l'os vivant. Le type même des expérimentations utilisées, s'il permet bien d'étudier ce qui se passe à la surface de l'os ne permet pas de prendre en compte ce qui se passe à l'intérieur de celui-ci sans en modifier les caractéristiques mécaniques. Enfin, le nombre et la complexité des paramètres à prendre en compte dépassent largment les possibilités des techniques classiques. C'est pourquoi, il est nécessaire de faire appel à des méthodologies nouvelles capables de prendre en compte un nombre très élevé de paramètres, de les calculer et de résoudre un nombre très important d'inconnues. Ces méthodologies doivent permettre l'expérimentation sans modifier l'objet de l'expérience et de calculer ce qui se passe à l'intérieur même de la mandibule.Cette méthode de simulation sur modèle physico-mathématique par informatique utilisée pour le calcul et l'élaboration des grandes structures métalliques (plate-forme off shore), celui de structures placées dans des conditions de contraintes particulières (prise en compte des tremblements de terre de magnitude 7 pour l'extension de l'usine de La Hague) ou bien celui des structures aéronautiques à matériaux composites a été ici appliquée à l'étude structurale de la mandibule.

     

胞元结构形式、材料性质对松质骨力学性能的影响

将均匀化理论与有限元方法相结合 ,讨论了骨小梁的弹性模量、泊松比和构成松质骨微结构的形式对松质骨力学性质的影响。结果表明微结构的形式和固体体分比确定时 ,松质骨的弹性模量与骨小梁弹性模量之间存在着确定的数量关系 ;当微结构的固体体分比较小时 ,骨小梁的泊松比对松质骨的弹性模量几乎没有影响。讨论了微结构形式对松质骨弹性模量的影响。     

GK型机械瓣空化可视化研究

对国产GK27型机械二尖瓣进行了单次关闭方式的离体空化实验，采用数码相机拍摄了空泡照片。机械瓣阻塞体关闭后，云状空泡出现在挡座周围，呈放射状向外运动，空化原因是机械瓣关闭时阻塞体与挡座的撞击形成的局部挤压射流，挤压缝隙出口射流速度高达9m/s，局部低压造成空化，在机理上，这是附壁射流引起的旋涡空化。关闭速度是衡量机械瓣空化趋势的重要指标之一。空化历时随心室载荷率的增加而增加，在载荷率为2750mmHg/s时，最大空化历时达440μs。机械瓣空化临界载荷率为420mmHg/s，这比动物实验所得的正常生理条件750mmHg/s低，因此在人体正常生理条件下，机械二尖瓣存在空化的可能。     

Airway occlusion pressure (P0.1) — A useful predictor for the weaning outcome in patients with acute respiratory failure —

Twenty-five patients who required mechanical ventilatory support (MVS) after major surgery or severe burns were studied to determine whether airway occlusion pressure (P_0.1) is a clinically useful indicator to predict the success or failure of the weaning trial. A total of 33 weaning trials were attempted on these patients. Of the 33 trials, 24 were followed by successful weaning and 9 by failure. Although the success group, when compared with the failure group, had a lower respiratory rate (P 0.001), a lower minute ventilation (P 0.001), a higher maximal voluntary ventilation to minute ventilation ratio (P 0.01) and a higher forced vital capacity (P 0.05), no threshold values separated the success from the failure group. The alveolar-arterial P_{O 2} gradient, with an Fi _{O 2} of 1.0, in weaning success and failure showed no statistical difference. In contrast, all patients in the success group had a P_0.1 of less than 3.5cmH₂O and those in the failure group had a P_0.1 of greater than 3.5cmH₂O (P 0.001). We conclude that P_0.1 is a clinically superior indicator for discontinuing MVS in patients with acute respiratory failure.(Okamoto K, Sato T, Morioka T: Airway occlusion pressure (P_0.1)—A useful predictor for the weaning outcome in patients with acute respiratory failure—. J Anesth 4: 95–101, 1990)     

Evaluation of conventional weaning criteria in patients with acute respiratory failure

We evaluated the reliability of conventional weaning criteria from a ventilator during 33 weaning trials on 25 patients with acute respiratory failure (ARF). Of 13 criteria, a ratio of maximal voluntary ventilation to minute ventilation (MV) 2, a vital capacity 12ml·kg^–1, a spontaneous respiratory rate 25 breaths·min^–1, and a MV 10l·min^–1 appeared to be useful for predicting successful weaning outcome. However, even using those criteria, there were many falsely-negative cases. The alveolar-arterial P_{O 2} gradient 350mmHg at an Fi _{O 2} 1.0 was not useful as a predictor of weaning outcome. The present study demonstrates that conventional criteria are frequently inaccurate for predicting weaning outcomes and suggests that the use of some of these criteria may unnecessarily prolong the length of ventilator support. Since ventilation of most patients with poor oxygenation can be successfully discontinued by placing them on a continuous positive airway pressure system, these results suggest that the improvement of oxygenation is not an indispensable prerequisite for weaning from mechanical ventilators.(Okamoto K, Iwamasa H, Dogomori H, et al.: Evaluation of conventional weaning criteria in patients with acute respiratory failure. J Anesth 4: 213–218, 1990)