自体软骨细胞团块植入修复兔陈旧性关节软骨缺损的实验研究

目的 观察自体软骨细胞团块植入对兔关节软骨缺损的修复作用. 方法 24只成年新西兰大白兔48侧膝关节,随机分为三组(n=16)并制备双膝关节股骨滑车软骨缺损模型.空白对照组无特殊处理,骨膜移植组将骨膜覆盖缺损并缝合于缺损两侧的股骨髁上,实验组将自体软骨细胞团块植入缺损中.术后3、6个月分别取材(n=8),进行大体和组织学观察,修复组织行Wakitani评分并进行比较. 结果实验组共成功取材11个缺损关节,9个为透明软骨修复,2个因植入细胞生长状态差未修复;骨膜移植组修复组织为纤维软骨或纤维组织,修复组织薄,基质异染弱;空白对照组仅有少量纤维组织填充缺损底部.修复组织Wakitani评分:实验组3.82分,骨膜移植组6.71分,空白对照组9.23分,差异有统计学意义(F=5.96,P=0.00). 结论自体软骨细胞团块植入能较好修复关节软骨缺损,修复的质量与植入细胞的质量有关.     

骨髓间充质干细胞复合消旋聚乳酸/明胶修复兔关节软骨缺损的实验研究

目的 研究骨髓间充质干细胞（marrow mesenchymal stem cells，MSCs）复合消旋聚乳酸（poly-L-lacticacid，PLLA）／明胶修复兔膝关节全层软骨缺损的效果。方法 4～6月龄青紫兰兔36只，体重2．5～3．5kg，雌雄不拘。体外分离培养MSCs，取第2代MSCs种植于PLLA／明胶支架体外复合培养。将36只青紫兰兔制备双侧膝关节全层软骨缺损模型，根据修复方法不同随机分为A、B、C3组（n=12）。A组，将MSCs与PLLA／明胶支架材料复合物植入兔双膝缺损处；B组，将单纯PLLA／明胶支架材料植入兔双膝缺损处；C组，缺损处不作任何处理，作为对照。A、B组在植入时均加入25μg／L转化生长因子β（transforming growth factorp1，TGF-β1）0．4ml。分别于术后4、8和12周，取材行大体、组织学及免疫组织化学染色观察，并将12周大体及组织学标本按照O’driscoll等评分标准进行评分。结果大体观察：术后12周，A组修复组织与正常软骨结合处完整，表面光滑，界限模糊；B、C组缺损处修复组织呈纤维组织或无修复，表面不平整或呈虫蚀样改变。组织学观察：A组术后4周，细胞数较多，呈梭形、圆形或椭圆形；8周修复组织与周围软骨大部分结合，细胞呈圆形，以透明软骨样细胞为主，有软骨陷窝，表层有梭形纤维样细胞；12周修复组织细胞为透明软骨样细胞，柱状排列，与周围软骨及软骨下骨整合良好；B组，术后4～8周细胞数较少，细胞层次排列差；12周修复组织菲薄，呈纤维软骨样，基质染色接近正常；C组，术后4～8周缺损组织由薄层纤维组织覆盖；12周缺损区纤维组织进一步增厚，与周围软骨未结合。免疫组织化学染色显示，A组修复组织Ⅱ型胶原染色呈阳性，B组呈弱阳性，C组无表达。术后12周大体观察总评分，A、B及C组分别为2．75±0．89、4．88±1．25和7．38±1．18，A组优于B、C组，B组优于C组，且差异均有统计学意义（P〈0．05）；组织学观察总评分，A、B及C组分别为3．88±1．36、8．38±1．06和13．13±1．96，A组与B、C组以及B组与C组差异均有统计学意义（P〈0．05）。结论 应用软骨组织工程原理，以PLLA／明胶为支架材料复合自体MSCs移植是一种修复软骨缺损行之有效的方法。     

自体骨膜延迟游离移植修复成年后关节软骨缺损的实验研究

目的：研究年龄对自体骨膜游离移植修复关节软骨缺损的影响,探讨延迟游离移植能否提高成年后骨膜修复软骨能力。方法：选中国白兔,成年兔20只,幼兔10只,分3组。A组：成年兔左膝骨膜直接游离移植组;B组：成年兔右膝骨膜延迟游离移植组;C组：幼兔骨膜直接游离移植组,取骨膜或骨膜新生组织、行光镜、电镜组织学观察比较。结果：移植前B、C组骨膜厚度、细胞计数及细胞活跃程度均优于A组（均为P＜0．01）,移植后12周3组关节软骨缺损获得不同程度修复,C组优于A组（P＜0．01）及B组（P＜0．05）,B组优于A组（P＜0．01）。结论：自体骨膜局部剥离、原位激活,体内培养、延迟游离移植可提高成年骨膜成软骨能力,更好地修复成年后关节软骨缺损。     

自体软骨细胞修复关节软骨缺损的机制探讨

目的:观察团块样自体软骨细胞植入关节软骨缺损后的病理变化,探讨自体软骨细胞移植修复关节软骨缺损的病理生理机制。方法:24只3.0kg以上4～6月龄新西兰大白兔,雌雄不限,随机分为两组:实验组和对照组。实验组12只,20%的速眠新(1mg/kg)肌肉注射麻醉后取肩关节软骨组织,0.2%Ⅱ型胶原酶消化分离软骨细胞,体外单层培养,细胞长成肉眼可见的膜状后收集固体的组织样细胞团,动物再次麻醉制造双膝股骨滑车4.0mm×6.0mm方形缺损,植入细胞团块,骨膜覆盖,缝合骨膜于双股骨髁上。对照组12只,同实验组手术方法进行缺损单纯骨膜移植。1、3、12、24周两组各3只动物空气栓塞处死取材,观察细胞团块变化和缺损修复情况。结果:1周时软骨细胞朝向关节面部分细胞变大变圆,产生大量基质;3周时此种变化更加明显,但骨膜与细胞团块已然不能分开;12周时缺损为类透明软骨组织修复;24周时修复组织为透明软骨样组织,对照组为纤维软骨组织修复。结论:关节软骨细胞体外聚集培养形成的细胞团块内的细胞有迁移生长能力;细胞团块移植方法植入的细胞数量大,表型好,细胞在缺损内不会流失;关节软骨缺损修复是由植入的细胞团块生长分化而来;自体关节软骨细胞团块植入关节缺损内后,在关节应力的影响下,先从朝向关节面的一侧逐渐发生细胞成熟分化和软骨基质产生,逐渐完成缺损的修复。     

藻酸钙复合自体软骨细胞修复羊膝关节负重区软骨缺损的实验研究

[目的]以中国山羊为动物模型,观察藻酸钙复合自体软骨细胞修复膝关节负重区软骨缺损的可行性。[方法]取羊肩关节软骨,分离、培养软骨细胞,蕃红"O"、 Giemsa及Ⅱ型胶原免疫组织化学染色对其进行鉴定。将自体软骨细胞与藻酸钙凝胶复合,修复山羊股骨髁负重区全层软骨缺损(直径6 mm),实验分为四组:(1)缺损旷置组:缺损内未植入任何组织;(2)骨膜覆盖组:自体骨膜覆盖缺损区;(3)藻酸钙+骨膜组:凝胶植入软骨缺损区,并用自体骨膜覆盖;(4)藻酸钙+细胞+骨膜组:藻酸钙复合自体软骨细胞植入软骨缺损区,自体骨膜覆盖;分别于手术后3、6个月取材,通过大体观察及组织学评分检测修复效果。[结果]软骨细胞复合物蕃红"O"、 Giemsa染色及Ⅱ型胶原免疫组化染色结果均为阳性,将藻酸钙凝胶-软骨细胞复合物用于羊负重区关节面软骨缺损修复,从大体观察和组织学评分进行比较,发现各组均有不同程度的组织修复,藻酸钙+细胞+骨膜组效果最好,与其他组差异有统计学意义(P<0.05)。[结论]藻酸钙凝胶-软骨细胞复合物结合自体骨膜覆盖,可较好修复山羊膝关节负重区软骨缺损。     

胶原复合梯度TCP修复关节软骨的形态学观察

目的采用新型双向三维可降解生物活性材料胶原复合梯度TCP（collagen complexTCP，Col／TCP）对兔关节软骨缺损进行修复，并对再生软骨进行组织形态学观察。方法取30只成年大白兔，体重2．0～2．5kg，雌雄不限，于双侧股骨外侧髁制作关节软骨缺损模型。于右侧植入Col／TCP修复缺损，作为实验组，左侧不予处理作为对照组。术后4、6、8、12和24周分别处死6只动物，取股骨外侧髁关节面行大体、组织学、透射电镜及Ⅱ型胶原免疫组织化学染色观察。采用Wakitanifa法软骨组织形态学评分评价修复组织质量。结果大体观察：实验组术后4周，缺损区由白色组织完全充填，表面较光滑，有光泽；12周，修复关节软骨组织与周围正常软骨基本一致，且与关节下骨结合紧密；24周，再生软骨未见明显退变。对照组观察期内均未见软骨组织形成，缺损由纤维组织填充，修复组织表面粗糙，与正常组织界线清楚。实验组术后4、6、8、12和24周组织学评分分别为（7．60&#177;0．98）、（5．69&#177;0．58）、（4．46&#177;0．85）、（4．35&#177;0．12）、（4．41&#177;0．58）分，对照组分别为（10．25&#177;1．05）、（9．04&#177;0．96）、（8．96&#177;0．88）、（8．88&#177;0．68）、（8．66&#177;0．54）分；Ⅱ型胶原含量实验组分别为0．28％&#177;0．01％、0．59％&#177;0．03％、0．68％&#177;0．02％、0．89％&#177;0．02％和0．90％&#177;0．01％，对照组为0．08％&#177;0．02％、0、09％&#177;0．04％、0．11％&#177;0．03％、0．25％&#177;0．03％和0．29％&#177;0．01％；两组各指标比较差异均有统计学意义（P〈0．05）。透射电镜观察实验组可见典型软骨细胞，而对照组为粗大胶原纤维，细胞少见。结论双向三维可降解生物活性材料Col／TCP在动物体内可诱导关节软骨缺损后的软骨修复。     

骨膜移植和钻孔术修复关节软骨缺损的实验比较

用中国白兔２４只，在股骨关书面造成６ｍｍ×８ｍｍ全层软骨缺损，分别进行游离骨膜自体移植和钻孔术。术后４、８周取材做组织学及电镜观察并进行比较。结果表明：（１）钻孔、移植骨膜和对照组的优势修复组织分别为类透明软骨、幼稚软骨和纤维组织。（２）修复组织平均数量，移植骨膜明显优于钻孔和对照组。（３）骨膜移植、钻孔和对照组修复组织来源分别为骨膜本身、髓腔和软骨下骨及与缺损毗连的软骨。初步结论：移植骨膜和软骨下骨钻孔均能修复关节软骨缺员，单纯刮除后修复能力最差。     

胶原杂化去抗原松质骨载体复合自体间充质干细胞修复骨软骨缺损

目的制备胶原杂化去抗原松质骨载体并复合自体间充质干细胞修复关节骨软骨缺损。方法脱脂、脱蛋白和脱钙的方法来制备去抗原松质骨载体，酸解-酶解法制备胶原进而杂化松质骨载体。扩增间充质干细胞，接种到胶原杂化松质骨载体，植入左膝关节（实验侧），右膝关节植入没有复合细胞的胶原杂化去抗原松质骨载体（对照侧），在第6、12、24、48周时结合Pineda评分观察实验侧和对照侧的骨软骨缺损的组织修复情况。结果实验侧自12周时出现初步的软骨表型，24周时最为明显，48周有部分退变；软骨下骨部分逐渐恢复。对照侧软骨缺损一直以纤维组织充填，软骨下骨有部分恢复。上述各时间点实验侧和对照侧的Pineda评分为16．600±0．966。17．600±0．699（6周）；6．600±0．843、14．800±0．789（12周）；3．300±0．483、13．600±0．843（24周）；3．500±0．527、14．100±0．876（48周），差异均有统计学意义（P〈0．05）。结论胶原杂化的去抗原松质骨载体复合自体间充质干细胞能够修复关节的骨软骨缺损。     

自体骨膜移植治疗关节软骨损伤的研究现状

关节软骨损伤修复大致分两类，即内源性修复和外源性修复。内源性修复也称骨髓刺激术，外源性修复包括生物移植和组织工程化关节软骨，前者包括骨膜、软骨膜移植，软骨细胞移植和骨-软骨移植；后者是体外构建种子细胞-载体复合物注入缺损区或者利用种子细胞悬液注入缺损区再用骨膜或软骨膜覆盖封闭软骨缺损的开口。两者均涉及到骨膜的成软骨作用。骨膜移植应用于临床治疗软骨损伤已有近20a历史，它有取材方便、对机体损害小等特点，但存在许多影响因素，限制了它的应用。本文就骨膜移植治疗关节软骨损伤的现状作一综述。     

兔自体耳软骨膜复合游离移植形成工程化软骨的实验研究

目的：探求用软骨腹复合移植的方法形成自体软骨的可行性。方法：将兔自体耳软骨膜包裹异体耳软骨脱细胞基质材料复合游离移植于兔背部皮下（I组），并在移植物附近皮下游离移植双层耳软骨膜（Ⅱa组）及单纯脱细胞的异体耳软骨基质（Ⅱb组）作为对照。在术后3周、6周分别取标本进行研究。结果：在3周、6周时，I组与Ⅱa组成软骨细胞的增殖变化情况差异有显性（P＜0．05），I组比Ⅱa组成软骨细胞的增殖明显旺盛，有的已经向软骨细胞转化，并有少量细胞外基质分泌，基质内软骨囊出现。Ⅱb组无成软骨细胞及软骨囊出现。结论：自体耳软骨膜与异体耳软骨脱细胞后的基质材料复合移植促进自体软骨生成。提示该基质材料有促进软骨膜细胞分化和生长的作用。     

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.     

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.     

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.     

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.