尿道细胞外基质在兔尿道重建中的应用

目的 评价尿道细胞外基质作为一种生物材料重建尿道的效果. 方法 切取新西兰兔的尿道制备尿道细胞外基质.手术切除实验组1～1.5 cm的尿道片段后用细胞外基质修复缺损,采用ELISA法检测术前、术后12、24及48 h血清TNFα的水平,评估术后兔的免疫反应状态.术后10d和3、6、24周取修复段尿道,行组织学观察并做尿道造影、尿道镜及尿流动力学检查. 结果 术后实验组血清TNFα水平较对照组略有升高,但无统计学意义(P>0.05).术后10 d,上皮细胞开始从边缘向细胞外基质移行并出现新生小血管;3周上皮细胞覆盖细胞外基质的整个管腔;6周出现排列不规则的平滑肌纤维;24周平滑肌数量明显增多,成束状排列.尿道造影、尿道镜及尿流动力学检测检查显示,尿道基质管壁光滑,排尿通畅. 结论 尿道细胞外基质是一种安全有效的尿道重建材料.     

血管细胞外基质和尿道细胞外基质修复兔尿道缺损的比较研究

目的　寻求较理想的尿道修复材料。　方法　切取 10只家兔的腹主动脉和尿道各 3cm ,制备成血管细胞外基质 (VECM)和尿道细胞外基质 (UECM)。另 2 0只分别切除尿道 2 .5cm并随机分为VECM修复组和UECM修复组。两组均于修复术后 10d、3周、6周及 2 4周行组织再生情况研究 ;另于术后 10周、2 4周各取 2只行膀胱尿道造影 ;2 4周两组各取 2只行尿动力学检测和尿道镜检查。　结果　制备的VECM和UECM均为白色透明状 ,但VECM较UECM弹性和机械强度好。缺损修复术后10d ,基质中见单层上皮细胞且有血管长入ECM ,基质和受体尿道连接处有炎性细胞浸润 ;3周时基质管腔已完全被上皮细胞覆盖 ;6周时可见平滑肌细胞再生 ,炎性细胞消失 ;2 4周后其组织结构与正常尿道组织结构一致。VECM修复组和UECM修复组相比其组织再生过程无差异。尿动力学检测VECM修复组和UECM修复组的膀胱容量分别为 (30 .2± 1.6 )ml和 (32 .1± 1.4 )ml、尿道最高压分别为(15 .2 7± 1.36 )mmHg和 (14 .6 8± 1.6 5 )mmHg、尿道最低压分别为 (12 .4 9± 1.2 3)mmHg和 (11.96±0 .98)mmHg ,差异无统计学意义 (P >0 .0 5 )。膀胱尿道造影可见尿道壁完整光滑通畅 ,不能分辨移植区与正常组织 ,无尿液外渗 ,无梗阻及结石形成 ;尿道镜检查证实VECM修复组和U     

冻干无细胞膀胱黏膜下基质修复兔尿道缺损

目的　探讨冻干无细胞膀胱黏膜下基质修复尿道缺损的效果。方法　应用反复冻融-酶法及冷冻干燥技术制备冻干无细胞人体膀胱黏膜下基质。 18只新西兰白兔建立尿道中段部分缺损模型 ,尿道缺损面积约 1 0cm× 0 5cm。其中 14只兔作为实验组 ,以冻干无细胞膀胱黏膜下基质修补尿道缺损 ,术后 1、2、3、4、8、12、2 4周分别取 2只行逆行性尿道造影 ,观察尿道情况 ,并采取尿道组织进行大体、组织学及超微结构观察 ;4只兔作为对照组 ,未采用任何材料修补尿道缺损 ,直接缝合尿道海绵体包膜、皮下组织及阴茎皮肤 ,术后 2、4周分别取 2只行逆行性尿道造影 ,采取尿道组织进行大体观察。结果　实验组 14只兔均未发现明显的尿道狭窄。冻干无细胞膀胱黏膜下基质组织相容性良好 ,移植后无细胞膀胱黏膜下基质内有细胞长入 ,新生血管形成 ,术后 2周无细胞膀胱黏膜下基质移植区完全上皮化。随着移植时间的延长 ,移植区胶原纤维排列由紊乱趋于规则。结论　冻干无细胞膀胱黏膜下基质能够诱导尿道黏膜细胞迁徙、生长和上皮化 ,初步认为可以作为尿道缺损修复材料。     

生物可降解性尿道内支架修复战伤性尿道狭窄的研究

目的建立战伤性尿道狭窄动物模型,探讨生物可降解性尿道内支架对其进行重建修复的可行性。方法将新西兰雄兔28只分为两组,实验组(n=20):以定位爆炸法建立尿道狭窄模型。一月后行逆行尿道造影、尿道镜检查,并切除狭窄段尿道,行病理组织学观察证实。后置入人工合成生物可降解尿道内支架,置入术后2、4、8、12周分别行逆行尿道造影、尿道镜检查以及尿流动力学检测。并在以上各时间点处死5只动物,取狭窄处尿道组织,观察组织学修复重建情况。对照组(n=8):于实验组爆炸处理后4周和支架置入12周,分别取对照组4只动物与实验组对比观察。结果实验组所有动物爆炸后4周在尿道球部狭窄形成稳定狭窄模型(狭窄段长5～10 mm,尿道腔缩窄50%以上)。尿道内支架置入后2周,组织学观察见黏膜上皮新生迹象,并有炎性细胞浸润;4周时上皮新生明显,炎性细胞消失;8周时出现尿道平滑肌细胞再生,12周时见损伤后尿道组织结构完全修复,与正常尿道组织比较差异无统计学意义(P>0.05)。。同时间点尿道镜检查证实尿道腔隙、黏膜形态结构无异于正常对照组。尿流动力学检测显示两组间差异无统计学意义(P>0.05)。。结论应用成功建立的战伤性尿道狭窄动物模型,证实生物可降解性尿道内支架能作为修复战伤性尿道狭窄的理想材料,具有损伤小,易操作,功能恢复快的特点。     

异体真皮细胞外基质重建尿道的实验和临床研究

目的：寻求理想的尿道修复材料。方法: 2只犬真皮脱细胞处理后制成真皮细胞外基质框架;18只犬分为2组;异体真皮细胞外基质（ECM）移植组（实验组）15只,异体真皮移植组（对照组）3只,全麻下将尿道中段切除5cm,将同样长度真皮ECM或异体真皮缝成直径0．3cm管状替代缺损尿道,8F硅塑管留置4周,实验组分别于术后1,3,6,12,24周每次3只取材行光镜,电镜及免疫组化检查。结果：组织学显示：1周时移植物边缘腔内面有尿上皮,管壁可见少量肌束,6周时移植物区尿路上皮达4－5层,肌层分布均匀,24周后移植物已无法与宿主尿道辨别,对照组术后8－10d移植物坏死出现尿瘘,在实验基础上用于临床2例均获成功。结论ECM为理想的尿道修复材料。     

尿道细胞外基质的研制

目的 探讨尿道细胞外基质(ECM)的制备方法。方法 采用4因素3水平，9次实验的正交设计[L9(3^4)]。切取37只兔的尿道，27条按正交设计随机分为9组行尿道脱细胞处理，试验重复3次。采用HE染色及计算机图像分析对尿道基质进行残余细胞成分计数，统计分析获得最佳方法：0．4％胰蛋白酶、l％甲醛加0．2％戊二醛、40U／ml DNA酶(A3B2C3方案)。另l0条兔尿道制备成尿道ECM并用于同种异体尿道缺损修复实验；分别于修复术后l0d，3、6及24周取材观察缺损修复处组织再生情况。结果 各组脱细胞后残余细胞成分量均不相同，第7、9组未发现细胞残余成分；制备的尿道ECM经扫描电镜分析未发观细胞残片。缺损修复实验术后10d，基质中见单层上皮细胞，且有血管长入ECM中，但管径较小，基质和受体尿道连接处有炎性细胞浸润；3周时尿道ECM管腔已完全被上皮细胞覆盖；6周时可见平滑肌细胞再生，炎性细胞消失。24周后基本结构近似正常。结论 制备尿道细胞外基质中3个关键条件的最佳水平为A3B2C3，即在尿道脱细胞处理过程中采用0．4％胰蛋白酶、1％甲醛加0．2％戊二醛、40U／ml DNA酶。     

应用异体脱细胞尿道基质修复尿道缺损

目的探讨应用同种脱细胞尿道基质修复尿道缺损的可行性。方法将14只雄性新西兰兔分为两组，切除实验组长约1.0～1．5cm的尿道，用相应长度脱细胞尿道基质修复；对照组行假手术。术后行尿道造影并取尿道标本作病理检查。结果12只实验兔的脱细胞基质移植物没有移位。除2例狭窄、2例尿瘘外，其余满意效果。病理检测示，术后3周尿道管腔上皮化，6个月基质中平滑肌及血管再生明显。结论同种脱细胞尿道基质材料可以修复兔尿道部分缺损。     

尿道上皮细胞/片状多孔丝素蛋白支架复合物修复兔尿道缺损的实验研究

目的探索用尿道上皮细胞/片状多孔丝素蛋白支架复合物修补长段尿道缺损的可行性及效果。方法取雄性新西兰兔(2.5kg)27只,随机分成3组:实验组:尿道上皮细胞/多孔丝素蛋白支架复合物组(n=9);对照组Ⅰ:假手术组(n=9);对照组Ⅱ:尿道缺损组(n=9)。三组共同饲养4周和16周后,分别对手术部位行病理学检查,8周后分别进行膀胱尿道造影、尿动力检测(尿道测压)和病理检测。结果 27只兔实验过程中无一例死亡。对照组Ⅰ术后4、8及16周,尿道组织结构无明显区别,尿道上皮细胞均匀覆盖,层数约4~5层,排列规则,未见炎症细胞。对照组Ⅱ术后4、8及16周瘢痕形成,组织质地坚韧,腔壁纤维化形成,可见大量的纤维组织及成纤维细胞,黏膜缺损:实验组术后4周时可见较多炎症细胞,材料表面细胞黏附,层数约6~8层,丝素蛋白复合体发生扭曲,术后8周片状多孔丝素蛋白支架降解成碎片状,组织均匀覆盖;术后16周尿道上皮细胞排列均匀,层数约4~5层,无明显炎症细胞浸润,可见较多血管,与对照组Ⅰ相似。术后8周,对照组Ⅰ膀胱尿道造影显示尿道黏膜连续性好,管腔光滑,管径均匀。对照组Ⅱ造影片显示尿道黏膜连续性的中断,管腔毛糙,尿道管径变细,呈现尿道狭窄的表现。实验组膀胱尿道造影提示尿道黏膜的连续性良好,管腔稍毛糙,管径与对照组Ⅰ基本一致。尿道测压:实验组术后8周手术部位的尿道阻力平均值(15.25±1.72)cmH_2O,对照组Ⅰ尿道阻力的平均值为(14.85±1.96)cmH_2O,两组对比无统计学差异(P0.05),对照组Ⅱ尿道阻力平均值为(27.83±3.71)cmH_2O,阻力明显增高,与实验组及对照组Ⅰ相比均有明显的统计学差异(P0.05)。结论尿道上皮细胞/多孔丝素蛋白支架复合物可以作为尿道修复的支架,具有促进尿道缺损修复的能力。     

口腔黏膜细胞与膀胱黏膜下脱细胞基质复合物构建组织工程化尿道的实验研究

目的 探讨以兔口腔黏膜细胞与同种异体膀胱黏膜下脱细胞基质(BAMG)复合物构建组织工程化尿道的可行性.方法 新西兰雄性兔24只,距尿道外口2.0 cm剥离尿道黏膜(2.0 cm×0.8 cm)后,随机分实验组和对照组,每组12只.切取实验组兔口腔黏膜组织分离细胞,在有灭活的3T3细胞培养皿上进行培养扩增,将培养获得的第2代口腔黏膜细胞种植于BAMG(2.2 cm×1.0 cm)上,植入实验组兔尿道缺损区域;对照组单纯采用无细胞植入的BAMG修复尿道.分别于术后1、2、6个月观察动物排尿情况,行尿道造影,8 F尿管插管确定有无狭窄;随后处死实验兔,取修复段尿道黏膜组织行组织学检查.结果 细胞培养获得的口腔黏膜细胞形态均一,生长良好;组织形态学、扫描电镜观察见口腔黏膜细胞与BAMG具有良好的相容性.实验组兔术后1、2、6个月伤口愈合良好、排尿通畅,无尿瘘发生,组织学和尿道造影检查显示带细胞修复的尿道形态完整、清晰宽敞,无狭窄发生;术后6个月植入的口腔黏膜细胞仍然存在,并明显扩增.对照组兔则出现排尿困难、尿道狭窄,光镜下发现黏膜及黏膜下存在严重的炎症反应.结论 兔口腔黏膜细胞与同种异体BAMG复合后,可成功用于尿道缺损的修复,构建组织工程化尿道.     

脱细胞尿道细胞外基质修复尿道缺损的临床研究

目的 总结新型替代材料修复尿道缺损的临床经验.方法 采用组织工程学材料脱细胞尿道细胞外基质(ECM)修复男性长段尿道缺损8例.患者平均年龄56岁.病程3～60个月,平均16.7个月.其中陈旧性前尿道狭窄4例、球部尿道狭窄2例、狭窄段从前尿道延伸到后尿道2例.狭窄长度3～8 cm,平均5 cm.结果 8例随访3～21个月,平均12.5个月.术后6周拔除尿管2例,8周拔管6例.无狭窄、尿瘘,排尿通畅7例,1例排尿不畅者定期行尿道扩张.术后8周尿道造影显示尿道通畅,未见吻合口狭窄.结论 脱细胞尿道细胞外基质为机体提供了良好的供宿主组织爬行替代的框架,在修补后可有效地与宿主组织融合,修补后的尿道愈合良好.     

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.