分化型甲状腺癌术后甲状旁腺功能减退风险综合预测模型建立

目的 探讨分化型甲状腺癌术后甲状旁腺功能减退的影响因素,建立分化型甲状腺癌术后甲状旁腺功能减退风险综合预测模型。方法 回顾性分析2018年9月至2019年12月蚌埠医学院第一附属医院肿瘤外科收治的100例分化型甲状腺癌病人的临床资料。（1）根据术后4 h外周静脉血甲状旁腺激素值分为减退组（23例）与正常组（77例）。对两组指标进行多因素Logistic回归分析,用其中差异有统计学意义的指标构建分化型甲状腺癌术后甲状旁腺功能减退风险综合预测模型,并评估此模型的性能。（2）根据术后6个月外周静脉血甲状旁腺激素值将术后甲状旁腺功能减退病人分为暂时性减退组（17例）和永久性减退组（6例）,对两组指标进行比较分析。结果 多因素分析表明,淋巴结清扫方式、原位保留甲状旁腺情况及淋巴结转移情况是术后甲状旁腺功能减退的独立影响因素。术后甲状旁腺功能减退的预测模型为：P=Exp（2.271-2.274X1-1.934X2-1.425X3）/［1+Exp（2.271-2.274X1-1.934X2-1.425X3）］,其中X1=淋巴结清扫方式,X2=原位保留甲状旁腺情况,X3=淋巴结转移情况。曲线下面积为86.3%,截点值为0.312,敏感度为80.1%,特异度为 85.3%。永久性甲状旁腺功能减退的发生与有效原位保留甲状旁腺情况密切相关。结论 分化型甲状腺癌术后甲状旁腺功能减退综合预测模型对术后甲状旁腺功能减退风险具有较好的预测能力。     

双侧甲状腺切除术后甲状旁腺功能减退临床因素分析及防治

目的:探讨双侧甲状腺切除术后患者甲状旁腺功能减退与各临床因素的关系,总结术后甲状旁腺功能减退的预防和治疗。方法:2011年1—12月行双侧甲状腺手术患者193例,所有患者于术后第1、2天检测血钙及甲状旁腺素(PTH),术后1、3、6个月随访血钙和PTH。术后PTH低于正常值患者予口服碳酸钙和维生素D。结果:193例患者中25例(13.0%)出现甲状旁腺功能减退,其中19例(9.8%)为暂时性甲状旁腺功能减退,6例(3.1%)为永久性甲状旁腺功能减退。不同年龄、性别患者术后甲状旁腺功能减退发生率差异无统计学意义(P>0.05)。甲状腺恶性肿瘤、术中行淋巴结清除患者术后甲状旁腺功能减退发生率(24.7%、20.9%)高于良性肿瘤、未行淋巴结清除患者(5.2%、8.7%,P<0.01、P<0.05)。术中有甲状旁腺误切患者与无误切患者术后甲状旁腺功能减退发生率差异无统计学意义(24.0%vs 11.3%,P=0.08)。永久性甲状旁腺功能减退患者中行颈淋巴结清除者100%(6/6)、甲状旁腺误切者83.3%(5/6),两者比例均高于暂时性甲状旁腺功能减退患者(P<0.05、P<0.01)。25例甲状旁腺功能减退患者补充碳酸钙和维生素D后1例出现低钙血症。结论:甲状旁腺功能减退与患者的年龄、性别无关,与患者手术范围有关,颈淋巴结清除和甲状旁腺误切更易导致永久性甲状旁腺功能减退。术后选择性补充碳酸钙和维生素D可以有效减少低钙血症的发生。     

改良Miccoli术式下甲状腺全切除病人甲状旁腺功能保护的研究

目的:探讨甲状腺全切除术后病人甲状旁腺功能减退的影响因素及改良Miccoli术式对于甲状旁腺功能保护的作用。方法:回顾性分析2012年8月至2013年7月在我科行甲状腺全切除的206例病人临床病理资料,根据手术范围分为甲状腺全切除组、全切除+单侧中央区清扫组、全切除+双侧中央区清扫组,对术后甲状旁腺功能减退的可能因素进行分析。结果:206例病人中33例出现甲状旁腺功能减退(16.0%),其中1例为永久性甲状旁腺功能减退(0.5%)。不同年龄、性别、原发灶手术范围的病人术后甲状旁腺功能减退的发生无统计学差异(P0.05)。甲状腺恶性肿瘤(P=0.048)、原位保留甲状旁腺数量减少(P=0.003)、中央区淋巴结转移7枚(P=0.036)的病人,易发生甲状旁腺功能减退。结论:术后甲状旁腺功能减退与原发灶性质、原位保留甲状旁腺数量、中央区淋巴结转移数量有关,改良Miccoli术式在一定程度有利于术中更好地发现和保护甲状旁腺。     

甲状腺全切除术后暂时性甲状旁腺功能减退危险因素分析

目的 探讨甲状腺全切除术后暂时性甲状旁腺功能减退发生的危险因素及术后常规补钙的临床价值。方法 回顾性分析2017年1-10月于北京大学深圳医院行甲状腺全切除术的237例病人资料,所有病人术后当天给予预防性补钙,且于术后第1天均复查甲状腺素（PTH）、血钙,术后1、3、6个月随访PTH及血钙水平。统计所有病人的临床数据并进行数据分析。结果 （1）237例中出现术后甲状旁腺功能减退的病人139例（58.6%）,其中暂时性甲状旁腺功能减退的病人136例（57.3%）,永久性甲状旁腺功能减退3例（1.3%）。（2）不同年龄、性别、手术路径与术后暂时性甲状旁腺功能减退发生率差异无统计学意义（P＞0.05）。（3）淋巴结清扫范围、是否再次手术及是否误切甲状旁腺与术后暂时性甲状旁腺功能减退发生率差异有统计学意义（P＜0.05）。结论 （1）术后暂时性甲状旁腺功能减退与年龄、性别、手术路径无关,淋巴结清扫范围大、再次手术及甲状旁腺误切更容易导致甲状旁腺功能减退。（2）术后第1天检测PTH能较血钙更好地预测术后甲状旁腺功能减退的发生情况。（3）术后预防性使用钙剂及维生素D3可有效预防低钙血症的发生。     

甲状腺癌根治术致甲状旁腺功能减退的危险因素及预防

目的:探讨甲状腺癌根治术中可能导致甲状旁腺功能减退的危险因素及预防措施。方法:回顾性分析首都医科大学附属北京同仁医院普通外科2014年全年由同一外科医师实施的75例甲状腺癌手术的临床资料。结果:全组术后发生甲状旁腺功能减退20例(26.67%),其中暂时性甲状旁腺功能减退19例(25.33%),永久性甲状旁腺功能减退1例(1.33%)。甲状腺全切术患者甲状旁腺功能减退发生率明显高于甲状腺近全切除术患者(46.88%vs.11.63%,P0.05);行VI区淋巴结清扫患者甲状旁腺功能减退发生率明显高于未行VI区淋巴结清扫患者(45.71%vs.10.00%,P0.05);同时行自体甲状旁腺移植术患者甲状旁腺功能减退发生率高于未行甲状旁腺移植患者,但差异无统计学意义(50.00%vs.22.22%,P0.05)。结论:甲状腺全切和Ⅵ区淋巴结清扫是导致甲状旁腺功能减退的危险因素。术中精细解剖甲状腺后被膜,尤其是尽可能保留下甲状旁腺血运,术后应用预防性药物可能有助于甲状旁腺功能的保护。     

甲状旁腺的术中观察及术后甲状旁腺功能减退的探讨

目的在甲状腺手术中认识甲状旁腺的局部解剖及甲状腺手术切除范围和甲状旁腺功能减退的关系，探讨术后甲状旁腺功能减退的原因及预防治疗措施。方法回顾2582例甲状腺手术患者的临床资料并术后随访。结果其中对721例双侧甲状腺侧叶全切者行术中探察，发现甲状腺病理状态下甲状旁腺的局部解剖位置及数量变异大，探察到的每种情况术后暂时性甲状旁腺功能减退发生率各不相同，其中上下甲状旁腺双侧均不明显组永久性甲状旁腺功能减退发生1例。2453例手术中行甲状腺部分切除、单侧叶次全切除、单侧叶全切除、双侧叶全切除、双侧叶全切及颈淋巴结清扫者（即甲状腺癌根治）暂时性甲状旁腺功能减退发生率依次增高，其中以双侧叶次全切除暂时性甲状旁腺功能减退发生率最高。且又因甲状腺疾病病种各不相同，甲状旁腺功能减退发生率亦各不相同。结论术后甲状旁腺功能减退的发生与手术操作、甲状旁腺的局部解剖及其变异、甲状腺手术切除范围、巨大甲状腺及其内巨大包块对双侧甲状腺后被膜深面组织的压迫，甲状腺疾病病种不同而手术难度各异等皆有关系。     

甲状腺手术中甲状旁腺保护要点与技巧

随着甲状腺癌发病率逐年增长,甲状腺癌术后甲状旁腺功能减退的病人数量也逐年增高,如何预防甲状旁腺功能减退也成为了甲状腺外科医生最关注的焦点之一。手术医生应有强烈的甲状旁腺保护意识,精细化被膜解剖,选择恰当的手术方式,通过术中肉眼辨认、探查、甲状旁腺显影等技术确定其的位置,合理运用高级能量平台,避免对甲状旁腺造成伤害。对于无法原位保留或误切的甲状旁腺,也可通过移植的方法,尽可能降低发生永久性甲状旁腺功能减退的风险。     

甲状旁腺自体移植术发展历程及展望

正甲状旁腺功能减退是甲状腺与甲状旁腺术后常见并发症,其引起的顽固性低钙血症不仅影响病人生活质量,严重者甚至危及生命。全甲状腺切除术后,有14%~60%病人出现暂时性甲状旁腺功能减退,而1%~4%的病人出现永久性甲状旁腺功能减退~([1]);需要清扫双侧中央区淋巴结脂肪组织或再次手术病人更易出现甲状旁腺功能减退~([2])。甲状旁腺全切除或次全切除术后亦会出现暂时性或永久性甲状旁腺功能减退。钙剂与维生素D制剂只能暂时缓解     

达芬奇机器人甲状腺手术中甲状旁腺的损伤因素及保护

目的分析达芬奇机器人甲状腺手术中甲状旁腺损伤的相关因素,探讨甲状旁腺保护的方法,避免永久性甲状旁腺功能减退的发生。 方法回顾性分析2014年1月至2016年5月在济南军区总医院甲状腺乳腺外科行达芬奇机器人甲状腺手术的190例患者的临床资料,统计术后患者出现低甲状旁腺激素(PTH)及低血钙的发生率,分析术后发生甲状旁腺功能减退的相关因素,探讨术中如何保护甲状旁腺及其功能。 结果患者术后暂时性低PTH的发生率为20.53%(39/190),暂时性低血钙的发生率为23.68%(45/190),术后随访无永久性甲状旁腺功能减退发生。甲状腺全切术后低PTH、低血钙的发生率高于腺叶 ＋ 峡部切除术者(χ²＝14.789,11.604;P＝0.000,0.001)。行中央区淋巴结清扫的患者术后低PTH、低血钙的发生率高于未清扫者(χ²＝11.200,17.771;P＝0.001,0.000)。甲状旁腺原位保留者术后低PTH、低血钙的发生率低于切除后自体移植者(χ²＝5.536,4.851,6.140,5.453;P＝0.019,0.028,0.013,0.020)。 结论在达芬奇机器人甲状腺手术中,甲状腺全切除、中央区淋巴结清扫、甲状旁腺切除后自体移植是造成患者术后暂时性甲状旁腺功能减退的重要影响因素。在达芬奇机器人手术系统下,准确识别甲状旁腺,精细化手术操作,原位保护甲状旁腺及血供,是预防永久性甲状旁腺功能减退的有效方法。     

甲状腺切除术后甲状旁腺功能减退的危险因素分析

目的:旨在分析甲状腺切除术后甲状旁腺功能减退的危险因素。方法:收集上海交通大学医学院附属瑞金医院卢湾分院普外科2015年1月至2017年12月行甲状腺手术病人的临床资料,分析一般资料、手术相关资料以及围术期检查指标等。Logistic多因素回归分析采用Enter法,评估一过性(术后6个月)和长期(≥术后6个月)甲状旁腺功能减退的危险因素。结果:共收集1 381例病人资料,男343例(24.84%),女1 038例(75.16%),平均年龄为(47.8±13.0)岁。术后发生一过性甲状旁腺功能减退456例(33.02%),长期甲状旁腺功能减退21例(1.52%)。多因素分析发现,术后一过性甲状旁腺功能减退相关的危险因素是女性(P0.001,OR=2.049)、双侧甲状腺切除(P0.001,OR=2.999)、淋巴结清扫(P=0.001,OR=1.673)、手术时间(P=0.043,OR=1.004)、切除甲状腺最大径(P=0.040,OR=1.144)、术前血钙(P0.001,OR=0.018)。术后长期甲状旁腺功能减退相关的危险因素是双侧甲状腺切除(P0.046,OR=3.784)、术后第1天PTH(P0.001,OR=0.064)。结论:女性、双侧甲状腺切除、淋巴结清扫、手术时间、术前血钙是甲状腺术后一过性甲状旁腺功能减退的危险因素。双侧甲状腺切除是甲状腺术后长期甲状旁腺功能减退的危险因素,术后第1天PTH对于病人长期甲状旁腺功能减退有预测作用。     

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 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.     

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.     

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.     

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.     

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.