鸡尾酒镇痛疗法对前交叉韧带重建术后镇痛和关节功能的影响研究

目的 评估在关节镜下前交叉韧带（anterior cruciate ligament,ACL）重建术中应用膝关节周围和关节腔注射鸡尾酒治疗的术后镇痛效果及其对术后关节功能的影响。方法 收集113例病人,随机分为对照组及鸡尾酒组。对照组在ACL重建术后、缝合切口之前在膝关节切口局部及关节腔注射75%罗哌卡因注射液10 mL+0.9%氯化钠注射液10 mL;鸡尾酒组在ACL重建术后、缝合切口之前注射鸡尾酒配方。术后定期随访,采用疼痛数字分级法（NRS）评估病人膝关节疼痛程度,膝关节Lysholm评分评估功能情况。结果 两组最终各有50例入组。鸡尾酒组术后引流量为（54.40±20.11） mL,低于对照组的（74.40±18.53） mL;术后第1日、第3日的NRS评分分别为（1.74±0.69）分、（1.16±0.37）分,均明显低于对照组;术后3个月膝关节Lysholm评分为（87.44±2.34）分,高于对照组的（83.72±2.58）分;上述指标组间比较,差异均有统计学意义（P＜0.05）。但两组术后6个月膝关节Lysholm评分比较,差异无统计学意义（P＞0.05）。结论 ACL重建术中使用鸡尾酒镇痛方法,能有效减轻患肢术后疼痛,且有助于患肢早期康复锻炼。     

关节镜下前交叉韧带袖套状保残重建的疗效研究

目的 探讨关节镜下前交叉韧带（anterior crueiate ligament,ACL）袖套状保残重建术的临床疗效。方法 回顾性分析我科2018年3月至2020年1月行关节镜下ACL袖套状保残重建术治疗的30例病人,其中男17例,女13例;年龄为17~43岁。术前及术后2、6、12个月分别采用Lachman试验和前抽屉试验评估膝关节的稳定性;记录Lysholm评分和Tegner运动功能评分,术后12个月时行患膝MRI检查评估重建的ACL。结果 病人随访（14.53±2.48）个月（12~18个月）。术中未出现神经血管损伤病人,术后未出现伤口感染及固定排异反应。术后门诊随访时,前抽屉试验及Lachman试验均为阴性。术后12个月Lysholm评分为（95.5±6.6）分,显著高于术前的（37.9±7.3）分;Tegner功能评分为（6.4±0.8）分,显著高于术前的（1.9±0.5）分,差异均有统计学意义（t=41.482,P＜0.001;t=25.819,P＜0.001）。术后12个月复查MRI显示ACL显影良好。结论 关节镜下ACL袖套状保残重建术安全、微创、并发症少,术后能早期改善病人膝关节功能,值得临床推广。     

强化本体感觉训练及等速肌力训练对前交叉韧带重建术患者康复效果的影响

目的 探讨强化本体感觉训练及等速肌力训练对前交叉韧带（ACL）重建术患者康复效果的影响。方法选取2020年1月至2022年12月在我院诊治的ACL重建术患者82例,随机分为2组,每组各41例。对照组给予常规训练,研究组给予强化本体感觉训练及等速肌力训练。比较两组训练前后的膝关节本体感觉功能、等速肌力、关节疼痛程度及膝关节稳定性,以及康复效果。结果 训练后,两组患侧15°重现差值、患侧45°重现差值、患侧75°重现差值较训练前均降低（P<0.05）,且研究组明显低于对照组（P<0.05）。训练后,两组伸屈膝相对峰力矩（PT/BW）、屈膝峰力矩值（PT）、伸膝PT、腘绳肌与股四头肌的肌力比值（H/Q）均较训练前升高（P<0.05）,且研究组明显高于对照组（P<0.05）。训练后,两组视觉模拟评分法（VAS）评分、Lachman试验胫骨前移较训练前均降低（P<0.05）,且研究组明显低于对照组（P<0.05）。研究组康复优良率为90.24%,明显高于对照组的73.17%(P<0.05)。结论 强化本体感觉训练及等速肌力训练应用于ACL重建术患者,可有...     

应用标准化视频指导ACL重建术后病人康复的效果评价

目的 探讨标准化康复视频在前交叉韧带（anterior cruciate ligament, ACL）重建术后病人功能锻炼中的指导效果。方法 以2015年2月至2016年10月于我科就诊的130例ACL重建术病人为研究对象,按照入院时间将其分为两组,观察组62例病人,术后应用我科制作的标准化视频指导康复;对照组68例病人,术后按照传统的方法,提供书面康复训练计划指导病人康复,比较两组病人的住院时间、膝关节Lysholm功能评分及康复知识熟练掌握率、术后锻炼依从率、住院满意率等指标。结果 观察组病人的康复知识熟练掌握率、术后锻炼依从率、住院满意率分别为95.1%、95.1%、100.0%,显著高于对照组（64.7%、61.7%、79.1%）;观察组的住院时间为（6.8±1.8） d,较对照组的（9.2±2.3） d显著下降;观察组术后6个月的膝关节Lysholm功能评分为（90.2±3.5）分,较对照组的（70.8±2.8）分显著升高。上述指标组间比较的差异均有统计学意义（P均＜0.001）。结论 使用标准化康复视频指导ACL重建术后病人功能锻炼能显著提高病人对于康复知识的熟练程度及康复锻炼依从性,有利于提升住院满意度,有效缩短住院时间,快速恢复病人膝关节功能。     

关节镜下双隧道技术不可吸收缝线固定治疗前交叉韧带胫骨止点撕脱骨折

目的 探讨关节镜下运用双隧道技术不可吸收缝线固定治疗前交叉韧带（anterior cruciate ligament, ACL）胫骨止点撕脱骨折的临床疗效。方法 回顾性分析我院2015年5月至2017年6月采用关节镜下双隧道技术不可吸收缝线固定治疗ACL胫骨止点撕脱骨折10例,收集手术时间、术中出血量、前抽屉试验及Lachman试验情况;比较其手术前后的国际膝关节文献委员会（the international knee documentation committee, IKDC）膝关节评分及Lysholm膝关节功能评分;通过X线片评价骨折复位及愈合情况。结果 本组病人术后均未出现严重并发症,前抽屉试验及Lachman试验均为阴性。术后随访12~24个月,平均17.7个月。末次随访时的Lysholm评分和IKDC评分分别为（86.60±5.10）分、（88.40±5.76）分,均较术前显著提高,差异具有统计学意义（t=18.515,P＜0.001;t=20.672,P＜0.001）;复查X线片示骨折复位及愈合满意。结论 关节镜下运用双隧道技术不可吸收缝线固定治疗ACL胫骨止点撕脱骨折,可有效恢复膝关节稳定性,疗效满意。     

早期或晚期行关节镜下前交叉韧带重建的临床疗效对比

目的 对比早期或晚期行关节镜下前交叉韧带（anterior cruciate ligament, ACL）重建的临床疗效。方法 选取2015年1月至2016年11月在我院进行关节镜下单束自体腘绳肌腱重建手术治疗ACL的34例病人进行回顾性分析。其中伤后2周内进行重建手术治疗的17例纳入早期重建组,伤后2~6个月内进行重建治疗的17例纳入晚期重建组,对比两组病人的术后疼痛消除时间、肿胀消除时间和关节恢复正常活动的时间等一般临床指标,收集并比较其术前和术后18个月的Lysholm评分、术前国际膝关节文献委员会（the international knee documentation committee, IKDC）膝关节评分。结果 两组病人的手术时间、术中出血量比较,差异均无统计学意义（P均＞0.05）;早期重建组的术后疼痛消除时间、肿胀消除时间和关节恢复正常活动时间分别为（34.06±3.27） d、（13.71±2.36） d和（50.18±4.65） d,均显著高于晚期重建组的[（25.29±3.96） d、（9.29±2.91） d和（33.41±3.48） d]差异均有统计学意义（t=7.033,t=4.850,t=1.892,P均＜0.001）;术后18个月,早期重建组的Lysholm评分和IKDC评分分别为（89.00±5.83）分、（90.06±5.03）分,与晚期重建组的（90.94±5.55）分、（91.47±4.23）分相比,差异均无统计学意义（P均＞0.05）,且两组病人Lysholm量表各单项评分之间的差异也无统计学意义（P均＞0.05）。结论 早期或晚期关节镜下单束自体腘绳肌腱重建手术治疗膝关节ACL损伤的近期临床疗效相近,但晚期重建治疗病人的术后恢复较快。     

射频治疗对关节镜下半月板部分切除术早期疗效的影响

目的 探讨半月板部分切除术后使用射频汽化修整残留半月板对病人术后膝关节预后的影响。方法 前瞻性地纳入60例病人,随机分为两组,观察组（26例）病人采用膝关节镜下半月板部分切除+射频修整术,对照组病人（34例）采用膝关节镜下单纯半月板部分切除术。对比两组病人术后48 h伤口引流量及疼痛视觉模拟量表（visual analogue scale, VAS）评分;采用膝关节Lysholm评分标准评估膝关节功能,记录并比较两组病人术前及术后6个月随访时的Lysholm评分。结果 观察组和对照组病人的术后引流量分别为（51.15±22.69） ml、（63.24±23.45） ml,VAS评分分别为（1.45±0.50）分、（1.62±0.55）分,两组间比较,差异均无统计学意义（t=0.264,P=0.610;t=0.259,P=0.613）;所有入组病人术后的Lysholm评分为（91.58±5.78）分,均优于术前的（73.53±4.52）分,差异有统计学意义（t=8.012,P=0.005）;观察组及对照组术后的Lysholm评分分别为（90.00±5.54）分、（92.79±5.75）分,差异无统计学意义（t=0.219,P=0.641）。结论 关节镜下行半月板部分切除术的出血量与使用射频汽化仪无关,无论是否使用射频汽化修整残留半月板,病人术后膝关节的功能都能得到较好的恢复。     

全内保残技术与标准化重建技术在前交叉韧带重建中的疗效比较

目的:探讨前交叉韧带重建手术中全内保残技术的疗效和临床结果。方法:回顾性分析2018年1月至2019年12月收治的56例行前交叉韧带重建手术的病例。根据手术方式不同分为全内重建组和标准胫骨隧道组,全内重建组21例,男15例,女6例,年龄20~48(35.6±6.7)岁;标准胫骨隧道组35例,男26例,女9例,年龄22~51(33.7±9.6)岁。术前查体Lachman试验阳性,磁共振均提示前交叉韧带断裂。比较两组手术时间、编织后移植肌腱的长度及直径,术后1、2年国际膝关节评分委员会(International Knee Documentation Committee,IKDC)评分、Lysholm评分、Tegner评分和围手术期相关并发症。结果:两组患者均获随访,时间24~30(26.9±3.4)个月。术后切口愈合良好,末次随访时未出现失效或关节感染病例。两组手术时间、韧带直径、韧带长度等一般资料比较,差异无统计学意义(P>0.05)。两组术前,术后1、2年IKDC评分、Lysholm评分、Tegner评分比较,差异无统计学意义(P>0.05),但术后1、2年IKDC评分、Lysholm评分、Tegner评分均高于术前(P<0.05)。结论:在前交叉韧带重建手术中,采用保残全内技术和标准化重建技术都能获得相似的术后功能及膝关节稳定性,但是相比于标准化重建方式,保残全内组只取半腱肌,保留股薄肌,更大地保留胫骨侧骨量。     

前交叉韧带重建术后运动员等速肌力训练的研究

目的采用等速肌力锻炼系统对膝关节前交叉韧带重建术后运动员进行康复训练,通过测量肌肉力量评估等速肌力训练对运动员术后恢复的作用。方法选择2014年3月至2015年12月膝关节前交叉韧带(anterior cruciate ligament,ACL)断裂、需行重建手术的30例运动员患者纳入研究,其中男26例,女4例,年龄16~23岁,受伤至手术时间1~6.5个月。随机分成训练组15例(等速训练患侧肌力)和对照组15例(常规康复训练)并分别进行功能训练,在术后第12、24周进行肌力测试。结果术后12周、24周训练组在60°/s、120°/s测试屈肌及伸肌峰力矩值都有明显高于对照组,差异有统计学意义(P0.05)。结论等速康复力量训练对运动员ACL重建术后肌肉功能恢复有较好的促进作用,值得进一步推广。     

前交叉韧带保残重建术中保残策略病例对照研究

目的：比较前交叉韧带保残重建与非保残重建、保留残端重建与保留残根重建的临床疗效。方法：自2014年3月至2017年12月采用自体腘绳肌腱单束重建前交叉韧带断裂患者204例,根据前交叉韧带重建方式不同分为保留残端重建组（A组）、保留残根重建组（B组）和清理残端残根的非保残重建组（C组）。A组76例,男37例,女39例,年龄16~43（28.80±5.41）岁,受伤至手术时间2~11（3.68±1.04）周,采用保留残端前交叉韧带重建术。B组64例,男39例,女25例,年龄18~41（28.42±5.60）岁,受伤至手术时间2~10（3.36±1.68）周,采用保留残根前交叉韧带重建术。C组64例,男37例,女27例,年龄18~43（29.10±6.11）岁,受伤至手术时间3~11（3.54±1.46）周,采用清理残端残根的非保残重建术。术前、术后24个月采用膝关节活动度（range of motion,ROM）观察膝关节屈伸活动范围。术前及术后6、12、24个月采用Lysholm评分和国际膝关节文献委员会（International Knee Documentation Committee,IKDC）评分评估膝关节功能。结果：所有患者术后伤口Ⅰ期愈合,无血管、神经损伤及关节感染等并发症发生。所有患者获随访,A组随访24.00~45.96（35.52±14.40）个月,B组27.96~48.00（37.56±10.68）个月,C组24.00~66.00（37.08±13.44）个月,3组随访时间比较差异无统计学意义（P>0.05）。术后6个月,A组Lysholm评分（82.52±5.24）分,IKDC评分（79.92±3.44）分,高于B组的（80.74±3.14）分和（78.21±4.63）分,且高于C组的（79.22±3.63）分和（76.63±3.80）分（P<0.05）;术后12个月,A组Lysholm评分（89.84±5.13）分,IKDC评分（87.90±3.93）分,高于B组的（85.74±6.04）分和（83.62±5.64）,且高于C组的（82.83±3.43）分和（79.21±4.04）分（P<0.05）。结论：前交叉韧带保残重建术与非保残重建术相比保留了前交叉韧带残端组织,有利于促进肌腱移植物愈合和重塑,加速关节功能恢复。保残重建术中妥善固定残端组织,恢复其张力,是影响术后疗效的关键因素。     

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.     

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.     

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.