脊柱胸腰段应力分布与骨折相关性的三维有限元分析

【摘要】 目的：观察脊柱胸腰段骨折与椎体骨性结构及韧带间应力分布的相关性,探索脊柱胸腰段椎体骨折的力学机制。方法：招募8名健康男性青年志愿者,行脊柱全长X线片和CT检查排除脊柱畸形、肿瘤及骨病,对脊柱各椎体及股骨行骨密度测定排除骨质疏松。均行自T11椎体上终板至L2椎体下缘CT薄层扫描,将8名志愿者CT图像参数导入ABAQUS 2016软件中进行标准化,并进行有限元网格化构建。应用MIMICS 17.0、GEOMAGICS 15.0和PRO/ENGINEER 5.0软件处理,建立脊柱胸腰段有限元模型,测量模型相关参数,并验证模型有效性。在T11椎体上终板上加载竖直轴向载荷500N、附加扭矩10N·m模拟垂直压缩、前屈、后伸、左右侧屈、左右旋转7种运动状态,使用ABAQUS软件对有限元模型7种运动状态下的应力分布特点及变化规律进行分析,观察应力分布与脊柱胸腰段骨折的相关性。结果：建立的三维有限元模型共有309583个节点和428760个单元,包括4个椎体、3个椎间盘、前纵韧带、后纵韧带、横突间韧带、棘间韧带等结构。7种运动状态下的数据与文献报道的数据无明显偏差,模型有效。T11~L2椎体椎弓根截面积分别为135mm2、154mm2、105mm2、139.2mm2。应力云图结果显示各运动状态下高应力区存在于椎体的松质骨、椎弓根及其周围骨皮质。在垂直压缩状况下,T12椎体所受应力最大（617.4MPa）,前屈状态下T11所受应力最大（200.7MPa）,后伸、左右侧屈和左右旋转状态下L1椎体所受应力最大（314.2MPa、574.4MPa、626.2MPa、641.3MPa、527.1MPa）,且前屈体位时椎体所能承受的应力最小,左旋转时所能承受的应力最大。垂直压缩状况下T12椎体发生骨折, 前屈状态下T11发生骨折伴韧带损伤,后伸、左右侧屈和左右旋转状态下L1椎体发生骨折伴韧带损伤。骨折发生时,前纵韧带在后伸、左右侧屈状态下存在高应力区,后纵韧带在前屈状态下存在高应力区,横突间韧带和棘间韧带在前屈、左右侧屈、左右旋转状态下存在高应力区。结论：在构建包括重要韧带、椎间盘等软组织结构的脊柱胸腰段三维模型中,椎体松质骨、椎弓根及其周围骨皮质、韧带均存在高应力区,不同状态下所受应力最大椎体不同,发生骨折的椎体和韧带损伤也不同;L1椎弓根截面积最小,最易发生骨折。     

L5新型自稳定人工椎体生物力学性能的有限元分析

目的:采用有限元分析评估L5椎体次全切术后置入新型自稳定人工椎体的力学性能以及对周围组织的影响,为腰骶段脊柱结核等疾病的治疗提供新的选择.方法:提取1名健康志愿者腰骶段CT薄层扫描数据进行三维重建,构建腰骶段(L3-S1)脊柱生理组有限元模型并进行有效性验证.将L5椎体及邻近椎间盘切除后,分别置入新型自稳定人工椎体和钛...     

动力性胸腰保护器对中上胸椎保护的有限元研究

[目的]通过建立有限元模型,研究垂直坠地时中上胸椎(T1~7)在动力性胸腰保护器(简称胸腰护具)保护下所受的应力变化,评价其对中上胸椎(T1~7)的保护作用。[方法]根据中国力学可视人数据库,构建了加载胸腰护具与否的两组人体躯干部有限元模型,第一组模型没有加载胸腰护具,第二组模型加载胸腰护具,通过其垂直坠地与仿真地面的撞击试验,比较两组模型中上胸椎(T1~7)椎体上所受的应力,并进行统计学分析。[结果]在第二组模型中中上胸椎(T1~7)受到的应力比第一组明显减少,两组胸椎所受的最大应力经配对设计t检验,P<0.05,存在统计学意义。在第二组模型中加载护具的两侧肩带和腰围部所受的应力出现集中。[结论]胸腰护具可以明显减少垂直坠地时T1~7椎体所受的应力,具有预防老年人跌倒性中上胸椎骨折的作用。     

脊柱保护器对腰椎保护的有限元分析

[目的]应用三维有限元方法研究垂直加载状态下脊柱保护器对腰椎的保护作用。[方法]构建腰椎有限元模型和脊柱保护器有限元模型,将上述模型进行材料参数赋值。根据设定条件对研究对象进行垂直载荷的力学仿真试验,运算获得腰椎有限元模型的目标单元应力、应变。[结果]腰椎受垂直载荷条件下从接触瞬间到应力峰值过程中应力、应变随时间变化逐渐增大,两组比较L5椎体皮质骨承受等效应力最大,试验组为170 MPa,对照组为192 MPa。L2椎体松质骨承受等效应力最大,试验组为5.01 MPa,对照组为5.79 MPa。且L2椎体出现最大压缩主应变,试验组为2.66%,对照组为5.63%。统计分析,对照组与试验组的腰椎各节段皮质骨与松质骨应力均值比较,P0.05,差异有统计学意义。腰椎除第三节段压缩主应变P值为18.3,其余节段P0.05,差异有统计学意义。[结论]脊柱保护器可以明显减少垂直坠地时腰椎椎体所受的应力,分担载荷,对腰椎具有保护作用。     

胸腰段三维非线性有限元建模及临床意义

目的建立胸腰段三个椎体节段的三维非线性有限元模型并对模型的有效性进行验证。方法建立T12/L1/L2三个椎体节段的三维非线性有限元模型,该模型分别在垂直压缩力800N作用下,屈曲、后伸、侧弯、扭转力矩作用下,最大力矩皆为16N·m,分析模型的平均刚度、屈曲和后伸力矩与旋转角度的关系,观察椎间盘纤维环上的应力分布情况。结果模型的平均刚度及力矩-旋转角度关系曲线和其他作者的实测法所得结果基本一致;椎间盘纤维环上应力符合临床和其他作者有限元分析所得结果。结论本研究通过一种改良的测量建模法建立的胸腰段有限元模型符合脊柱生物力学的一般特点,可以对胸腰段和胸腰段内固定的生物力学进行研究。     

经皮骨移植增强的有限元研究

目的利用腰椎三维有限元模型,探讨松质骨粒(cancellous bone granule,CBG)和聚甲基丙烯酸甲酯(polymethylmethacrylate,PMMA)增强后对治疗节段和相邻非治疗节段椎体生物力学影响。方法 L1～L2的三维功能脊柱单位的有限元模型由脊柱尸体标本CT扫描后形成。分别模拟骨质疏松模型、CBG和PMMA增强,分析轴向压缩、前屈和后伸3种加载状态下手术前后治疗节段和相邻非治疗节段椎体应力和应变的变化。结果在压缩、前屈和后伸3种加载状态下,松质骨粒增强模型强化区最大的Von Mises应力/应变分别为0.457、0.469、0.499 MPa/0.459%、0.471%、0.501%;PMMA增强模型为0.864、0.824、0.966 MPa/0.029%、0.028%、0.033%;骨质疏松模型相应区域为0.237、0.253、0.258 MPa/0.698%、0.752%、0.759%。与骨质疏松模型比较,治疗节段增强区域的应力/应变明显改变。结论 CBG和PMMA均增强治疗节段的总体强度和刚度水平,有利于椎体功能的重建,但就材料力学相容性和生物相容性而言,CBG的增强优于PMMA增强。     

弯腰挺立手法治疗腰骶关节紊乱的有限元分析

目的:分析腰骶关节紊乱患者有限元模型及施加弯腰挺立手法后的位移、应力及作用机制。方法 :建立1例腰骶关节紊乱患者的三维有限模型,运用有限元分析方法对模型进行轴向、34°斜向上、垂直向上3种工况加载进行观察分析。结果:腰骶关节紊乱模型应力分布,L_5椎体集中在下终板中央、椎间盘集中在间盘中央,S_1及相关结构应力集中分布在椎体前后缘。模拟手法后应力主要集中在L_5椎体上终板前缘、后缘和下终板中央圆形区域,椎体后部相关结构集中在椎弓根腹侧、峡部和椎板背侧,椎间盘应力分散于椎体后缘;S_1椎体相关结构集中在骶骨椎体后缘和骶骨嵴上。位移结果:腰骶关节紊乱模型中左侧横突、上下关节突和棘突左侧部分向左明显移位,椎间盘向前突出移位。模拟手法后:L_5椎体下切迹向前上方移位,椎间孔面积增大,L_5椎体下关节突向前移行,骶骨上关节突向前下方移位,关节突关节距离加大,骶骨位移最大集中在椎体后缘和骶正中嵴上。结论:腰骶关节建模成功可进行有限元分析;弯腰挺立手法作用机制明确,用于治疗腰骶关节紊乱有效、安全可施。     

脊柱交界区终板抗压强度分布规律的生物力学研究

目的:探讨脊柱交界区终板不同位点抗压强度及其分布规律。方法:选用5具成年男性新鲜脊柱标本的颈胸段、胸腰段及腰骶段,共65个椎体125个终板,采用环形取点的方式,对每个终板平面的49个测试点用直径1.5mm的平底压头进行连续压缩加载试验,获得最大压缩力,所得数据进行统计分析。结果:以椎体为单位,颈胸段终板从C4开始抗压强度逐渐下降,至C7达到最低点,C7～T1明显升高。胸腰段各椎体终板的抗压强度呈依次上升趋势,腰骶段L3、L4终板抗压强度继续上升,L5出现降低,S1节段再次升高。颈胸段与胸腰段抗压强度均小于腰骶段(P<0.01)。上下终板抗压强度变化趋势相似。各段椎体抗压强度下终板强于上终板(P<0.01)。椎间隙相邻面上一椎体下终板的抗压强度大于下一椎体上终板(P<0.05)。由内至外,抗压强度逐渐增大(P<0.05)。颈胸段和腰骶段的后部终板抗压强度大于前部,而胸腰段为前部大于后部(P<0.05)。结论:不同节段终板的抗压强度分布规律不同,临床安放椎间置入物时需注意置入物的大小及放置位置。     

胸腰椎爆裂骨折手术治疗的研究进展

脊柱骨折中最常受累的节段是T10～L2，尤其是T11、L1、L2，脊柱胸腰段指T11～L2，爆裂骨折与高能创伤有关，常由于高处坠落伤所致。胸腰段椎体是胸椎后凸与腰椎前凸的转折点，又具有较大的活动度，因此最容易受到传导暴力造成损伤，其中垂直压缩暴力导致的爆裂骨折较多见。该型损伤的特点是脊柱中柱受累，在轴向应力的作用下使椎体呈爆     

骨质疏松性椎体压缩骨折强化术后骨组织-骨水泥界面生物力学应力再平衡机制的有限元研究

目的 ：明确脊柱骨质疏松性椎体压缩骨折（osteoporotic vertebral compression fracture,OVCF）骨水泥强化治疗后骨组织-骨水泥界面的生物力学应力再平衡机制及脊柱动态稳定重建效应。方法：选择甘肃中医药大学附属医院脊柱外科收治的OVCF患者（伤椎为T12和L1）为研究对象,提取薄层高精度的胸腰段CT影像数据,通过Mimics、Geomagic、Solidworks、Ansys Workbench有限元生物力学建模平台,建立三维数字化仿真生物力学模型,对伤椎运动节段在轴向、前屈、后伸、侧弯及旋转等不同运动工况下骨组织-骨水泥界面的等效应力进行量化研究。结果：脊柱OVCF骨水泥强化术后骨组织-骨水泥界面的等效应力极值和分布区间较术前明显优化,在轴向、前屈、后伸、侧弯及旋转等运动工况下,T12伤椎骨水泥强化治疗术后的最大主应力相比于术前显著下降,在相同的运动工况下分别为33.002MPa、35.639MPa、35.98MPa、60.458MPa、65.396MPa、60.177MPa、42.249MPa,尤其是前屈运动工况下,脊柱T12伤椎的最大主应力从...     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.