老年心脏手术后急性肾损伤可纠正的危险因素分析

目的 探讨老年心脏手术患者术后急性肾损伤(AKI)可纠正的危险因素,降低其发生率,改善预后.方法 收集广东省人民医院2007年1月至2009年12月年龄≥60岁心脏手术患者的临床资料.以RIFLE标准诊断的AKI为观察终点,术前最后一次血肌酐为基线值.Logistic回归分析确定心脏术后AKI的独立危险因素.结果 457例患者入组,313例(68.5％)术后发生AKI.Logistic回归分析显示,男性、年龄＞ 65岁、高血压、术前估算肾小球滤过率＜60 ml/min、术前尿酸＞450 μmol/L(OR 2.938,95％可信区间1.633 ～5.285)、体外循环＞120 min、机械通气时间延长、术后用血管紧张素抑制酶/血管紧张素受体抑制剂和利尿剂是心脏术后AKI的独立影响因素.结论 术前尿酸＞450 μmol/L是老年心脏手术患者术后AKI可纠正的危险因素.     

成人体外循环心脏手术后急性肾损伤的危险因素分析

目的 探讨成人体外循环心脏手术后急性肾损伤(AKI)的发病情况及危险因素.方法 回顾性分析2006年9月至2011年7月行体外循环心脏手术的成人患者6665例.根据术后是否发生AKI分为两组,AKI组1779例,非AKI组4886例.收集患者临床资料,采用单因素和多因素Logistic回归分析AKI发生的危险因素.结果 AKI组中102例(1.53％)进行了肾脏替代治疗(RRT),院内死亡44例;非AKI组死亡14例,AKI组住院病死率显著高于非AKI组患者(2.47％对0.29％,P＜0.01).多因素Logistic回归分析显示,男性、年龄(每增加10岁)、高血压史、糖尿病史、术前基础血肌酐值≥115μmol/L、术前血尿酸值≥420 μmol/L、术前左心室射血分数＜0.40、术前贫血、手术类型(主动脉瘤手术)、体外循环≥120 min、深低温停循环的应用、术后低血压、术后24 h内输血量≥1000 ml、术后机械通气≥72 h是体外循环心脏术后发生AKI的独立危险因素.结论 AKI是成人体外循环心脏手术后的常见并发症,与术后病死率的增加有关.AKI的发生与多种围手术期危险因素有关,应充分重视这些危险因素的评估和预防.     

1113例心脏瓣膜置换手术后急性肾损伤的临床分析

目的 研究不同类型心脏瓣膜置换手术后急性肾损伤（AKI）的发病情况及其危险因素。 方法 采用前瞻性队列研究。收集本院心外科2009年4月1日至2010年3月31日期间进行心脏瓣膜置换手术患者的临床资料,采用多因素回归方法筛选出各类心脏瓣膜置换患者术后发生AKI的危险因素。AKI诊断标准为48 h内Scr上升≥26.4 μmol/L或较基础值增加≥50%;和（或）尿量<0.5 ml?kg-1?h-1达6 h。结果 1113例瓣膜置换手术患者术后AKI发病率为33.24%,AKI患者住院病死率为6.49%,其死亡风险较非AKI患者增加5.373倍 （P < 0.01）。心脏瓣膜置换伴冠脉搭桥手术术后AKI发病率为75.00%,显著高于其它瓣膜置换手术类型（P < 0.01）。多因素非条件Logistic回归分析表明,年龄（每增加10岁）、男性、术中体外循环时间≥120 min以及心脏瓣膜置换合并冠脉搭桥手术是术后发生AKI的独立危险因素,OR值分别为1.455、2.110、1.768和2.994。 结论 AKI是心脏瓣膜置换手术后常见的严重并发症。心脏瓣膜置换合并冠脉搭桥手术术后更容易发生AKI。高龄、男性、术中体外循环时间≥120 min以及心脏瓣膜置换合并冠脉搭桥手术是心脏瓣膜置换术后发生AKI的独立危险因素。     

老年患者胃癌根治术后急性肾损伤的危险因素

目的 分析老年患者胃癌根治术后急性肾损伤(AKI)的危险因素。方法 回顾性收集接受胃癌根治手术老年患者691例的临床资料,男563例,女128例,年龄≥65岁,ASAⅠ—Ⅲ级。临床资料包括性别、年龄、体重、BMI、ASA分级、吸烟及饮酒史、术前合并症、手术时间、术中用药情况、术中液体出入量、术中尿量、术后住院时间、总住院时间等。根据患者术后是否发生AKI分为两组：AKI组和非AKI组。采用多因素Logistic回归分析发生术后AKI的危险因素。结果 有16例(2.3%)患者发生术后AKI。多因素Logistic回归分析结果显示,合并冠心病(OR=5.587,95%CI 1.355～23.029,P=0.017)和术中尿量减少(OR=0.997,95%CI 0.995～1.000,P=0.023)是老年患者胃癌根治术后AKI的独立危险因素。结论 术前合并冠心病及术中尿量减少是老年胃癌根治术患者术后发生AKI的独立危险因素。     

老年髋部骨折患者术后谵妄发生的危险因素分析

目的探讨老年髋部骨折患者术后谵妄发生的临床独立危险因素。方法回顾性分析自2013-04—2014-12诊治的272例老年髋部骨折,根据术后患者是否发生谵妄分为谵妄组和非谵妄组,相继采用单因素分析及Logistic多因素回归分析从14项可能危险因素中筛选出谵妄发生的独立危险因素。结果 63例术后发生谵妄,谵妄发生率为23.2%。单因素分析结果显示,高龄、术前白蛋白(35 g/L)、术前合并基础疾病数量(≥3种)、麻醉方式(全身麻醉/椎管内麻醉)、手术时间(≥2.5 h)、术后使用镇痛泵及术后发生低氧血症与谵妄的发生有显著的相关性关系,可能是谵妄发生的高危因素。Logistic多因素回归分析结果显示,高龄、术前白蛋白(35 g/L)、术前合并基础疾病数量(≥3种)及手术时间(≥2.5h)该4项危险因素为术后患者发生谵妄的高危独立危险因素。该4项危险因素的OR值分别为13.865、1.837、2.140、2.437。结论高龄、术前白蛋白35 g/L、术前合并基础疾病数量≥3种及手术时间≥2.5 h 4项危险因素为老年髋部患者术后发生谵妄的独立危险因素。     

DCD供肝肝移植术后早期急性肾损伤相关危险因素分析

目的分析心脏死亡器官捐献(DCD)供肝肝移植术后早期急性肾损伤(AKI)的相关危险因素。方法回顾性分析184例DCD供肝肝移植供、受体资料。根据术后早期是否发生AKI分为AKI组和非AKI组,并且对AKI组行AKI分期。比较两组一般资料和术前、术中、术后相关指标的差异。用Kaplan-Meier曲线分析非AKI组和AKI组不同分期累积存活率等预后情况。结果本研究纳入病例184例,术后早期发生AKI 68例(37.0%),其中AKI 1期31例,AKI 2期26例,AKI 3期11例,且发生多在术后3 d内。单因素分析结果显示术前白蛋白35 g/L、术前血清钠≤137 mmol/L、手术时间7.5 h、术中出血量3 000 m L、术中红细胞输注量15 U、术中尿量≤100 m L/h这6项指标为肝移植术后早期发生AKI的危险因素(均为P0.05)。Logistic多变量回归分析结果表明术中红细胞输注量15 U是肝移植术后早期发生AKI的独立危险因素[比值比(OR)1.061,95%可信区间(CI)1.008~1.118,P=0.024]。Kaplan-Meier生存曲线结果表明随着AKI程度不断加重,其累积存活率逐渐降低,差异有统计学意义(均为P0.05)。结论肝移植患者术后早期AKI的发生率较高,且严重程度与受体的短期和长期预后密切相关,术中大量输注红细胞是AKI发生的独立危险因素。     

腹膜后腹腔镜嗜铬细胞瘤切除术107例

目的 探讨腹膜后腹腔镜嗜铬细胞瘤切除术的安伞性及疗效.方法 回顾性分析107例嗜铬细胞瘤,肾上腺内102例,肾上腺外5例.采用腹膜后腹腔镜手术治疗,根据技术掌握程度分为3个时期:技术探索期、经验积累期及相对成熟期.结果 技术探索期完成10例:肿瘤平均直径4.2 cm,手术平均时间105 min,术中平均出血量620 ml.经验积累期完成66例,包括4例复发性嗜铬细胞瘤:肿瘤平均汽径5.7 cm,手术平均时间95 min,术中平均出血量350 ml.相对成熟期完成31例,包括5例肾上腺外嗜铬细胞瘤:肿瘤平均直径6.5 cm,手术平均时间75 min,术中平均出血量180rnl.各期均无围手术期死亡病例.结论 腹膜后腹腔镜嗜铬细胞瘤切除术安全可靠.肿瘤大小、是否复发及肿瘤部位不是决定能否采取腹腔镜手术的绝对因素.     

老年腰椎椎管狭窄症患者术后急性肾损伤的发生率及危险因素

目的探讨老年腰椎椎管狭窄症患者行经腰椎后路椎板切除椎间融合术后急性肾损伤(AKI)的发生率和危险因素。方法回顾性分析2017年6月—2019年6月因腰椎椎管狭窄症在本院接受后路腰椎椎板切除椎间融合术的老年(≥65岁)患者的临床资料,统计术后AKI的发生率。比较发生AKI的患者和未发生AKI的患者一般资料及术中资料,并采用单因素及多因素logistic回归模型分析术后发生AKI的危险因素。结果共纳入216例患者,其中男104例(48.15%)、女112例(51.85%),年龄65 ～ 76(69.32±3.58)岁。发生AKI 22例(10.19%),未发生AKI 194例(89.81%)。与未发生AKI的患者相比,发生AKI患者的年龄较大、术前血红蛋白和基础估计的肾小球滤过率(eGFR)较低、麻醉时间较长、术中尿量较少、术中出血量较多。单因素logistic回归分析显示,年龄、基础eGFR水平、术前血红蛋白水平、麻醉时间、术中尿量、术中出血量均为术后发生AKI的危险因素;多因素logistic回归分析显示,基础eGFR水平和术中尿量是术后发生AKI的独立危险因素。结论 AKI是老年腰椎椎管狭窄症患者术后常见并发症,基础eGFR水平和术中尿量是术后发生AKI的独立危险因素。     

腹腔镜切除5～10 cm肾上腺嗜铬细胞瘤的安全性分析

目的 探讨5～10 cm肾上腺嗜铬细胞瘤腹腔镜切除术的安全性. 方法 2001年1月至2007年6月在北京大学第一医院泌尿外科行肾上腺嗜铬细胞瘤切除的连续79例患者中肿瘤最大径5～10 cm者共41例,回顾分析其临床资料.腹腔镜组11例(其中2例中转开放,数据分析时排除在外),开放手术组30例.应用t检验、Mann-Whitney U检验对两组患者的临床资料及围手术期数据进行分析. 结果 两组患者年龄、肿瘤最大径、术前最高收缩压及舒张压、术前心率、血儿茶酚胺水平的差异均无统计学意义(P>0.05).腹腔镜组均经腹膜后途径.开放手术组经腹腔途径11例,经腹膜后途径19例.两组患者手术时间分别为(132±54)min和(178±64)min;术中出血量分别为100 ml(0～800 m1)和450 ml(0～9500 ml);术后住院时间分别为(7±2)d和(9±4)d,差异均有统计学意义(P<0.05).腹腔镜组术中均未输血,开放手术组术中输血量的中位值为225 ml(0～3800 ml).2组患者术中最高血压、最低血压、最快心率、最慢心率、收缩压增加基础血压30%的次数、收缩压≥200 mm Hg(1 mm Hg=0.133 kPa)次数、收缩压≤90 mm Hg次数、心率≥110次/min次数、心率≤50次/min次数的差异均无统计学意义(P>0.05).两组患者引流量、拔管时间、住ICU时间、术后开始进食时间、住院费用差异均无统计学意义(P>0.05). 结论 腹腔镜切除5～10 cm肾上腺嗜铬细胞瘤的手术时间、术中出血量、术中输血量、术后住院日较开放手术有优势,且术中血压、心率波动等指标不高于开放手术.因此,5～10 cm的肾上腺嗜铬细胞瘤不是腹腔镜的绝对禁忌,经验丰富的术者可以考虑开展腹腔镜手术切除较大肾上腺嗜铬细胞瘤.     

心脏死亡器官捐献肝移植术后并发急性肾损伤危险因素分析

目的探讨心脏死亡器官捐献(DCD)肝移植术后并发急性肾损伤(AKI)的危险因素。 方法回顾性分析2012年1月至2018年11月宁波市医疗中心李惠利医院肝胆胰外科159例DCD肝移植受者临床资料,根据改善全球肾脏病预后组织临床实践指南中AKI诊断标准将159例受者分为AKI组(34例)和对照组(125例)。采用两独立样本t检验比较两组受者年龄和术前血清白蛋白。采用Wilcoxon符号秩和检验比较两组受者术前终末期肝病模型(MELD)评分、术前体质指数(BMI)、供肝冷/热缺血时间、术中输液量、术中出血量、术中输血量、术中尿量、手术时间、术中去甲肾上腺素总用量及总住院天数。采用卡方检验比较两组受者性别、术前乙型肝炎、术中低血压、术后感染、肝移植术式及术后再次手术情况。将单因素分析中有统计学差异的变量纳入Logistic回归进行多因素分析。P<0.05为差异有统计学意义。 结果肝移植术后AKI发生率为21.4%(34/159)。单因素分析结果表明,AKI组与对照组受者术前MELD评分、术前血清白蛋白、术中输液量、术中出血量、术中尿量、手术时间、术中低血压及术后再次手术差异均有统计学意义(Z＝2.763, t＝－2.250, Z＝2.040, Z＝2.092, Z＝－3.303, Z＝－2.170, χ²＝8.227, χ²＝5.294, P均<0.05)。Logistic回归多因素分析结果显示：术前MELD评分、术前血清白蛋白、术中尿量和手术时间是DCD肝移植术后并发AKI的独立危险因素,差异均有统计学意义(P均<0.05)。 结论DCD肝移植术前应改善受者一般情况,提高围手术期营养水平,术中控制液体出入量,合理使用利尿剂和缩短手术时间,以降低受者术后AKI发生率。     

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.