关节镜治疗原发性冻结肩的疗效

目的观察关节镜下粘连松解术联合手法松解治疗原发性冻结肩的临床疗效。方法以84例原发性冻结肩患者为研究对象,按照随机数字表法分为研究组(42例)和对照组(42例),对照组实施手法松解治疗,研究组实施关节镜下粘连松解术术联合手法松解治疗,比较两组手治疗前后VAS、Constant-Murley、ASES和UCLA评分差异,测定两组肩关节活动度,观察治疗后12个月内冻结肩复发情况,评价患者治疗满意度。结果研究组治疗前12个月VAS评分显著低于对照组水平,Constant-Murley、ASES和UCLA评分显著高于对照组水平(P0.05),研究组肩关节各方向活动度均显著高于对照组水平(P0.05);研究组冻结肩复发率(14.29%)显著低于对照组水平(35.71%)(χ~2=5.143,P=0.0230.05);研究组治疗后治疗满意度水平(92.86%)显著高于对照组水平(76.19%)(χ~2=4.459,P=0.0350.05)。结论关节镜下粘连松解术联合手法松解可有效缓解原发性冻结肩患者疼痛反应,改善肩关节活动功能,降低冻结肩复发率,提高患者治疗满意度。     

关节镜下双后侧入路关节囊松解治疗顽固性冻结肩的临床研究

目的观察关节镜下双后侧入路关节囊松解治疗顽固性冻结肩的临床疗效。方法以130例顽固性冻结肩患者为研究对象,按照随机数字表法分为对照组(65例)和研究组(65例),对照组予以手法松解,研究组予以关节镜下双后侧入路关节囊松解,比较两组手术前后VAS、Constant-Murley和ASES评分差异,测定两组肩关节旋转角度,观察术后并发症。结果研究组术后6个月VAS评分显著低于对照组水平,Constant-Murley和ASES评分显著高于对照组水平(P0.05);研究组术后6个月外展、前屈、后伸和外旋等肩关节旋转角度均显著高于对照组水平(P0.05);研究组术后并发症总体发生率(9.23%)显著低于对照组水平(24.62%)(χ2=5.471,P=0.0190.05)。结论关节镜下双后侧入路关节囊松解术可有效缓解顽固性冻结肩患者疼痛反应,改善肩关节活动功能,降低术后并发症发生风险,安全性更高。     

一期手法松解关节镜下肩袖修补术治疗肩袖撕裂合并冻结肩的临床疗效

目的探讨一期手法松解联合关节镜下清理肩袖修补术治疗肩袖撕裂合并冻结肩的疗效。方法回顾分析2014年1月—2015年12月采用一期手法松解联合关节镜下清理肩袖修补术治疗的15例肩袖撕裂合并冻结肩患者(冻结肩组)临床资料,并与同期关节镜下肩袖修补术治疗的24例肩袖撕裂不合并冻结肩患者(非冻结肩组)进行比较。冻结肩组患者年龄大于非冻结肩组(P0.05);两组患者性别、肩袖撕裂分型、损伤侧别、合并糖尿病例数比较,差异均无统计学意义(P0.05)。术后肩关节疼痛程度采用疼痛视觉模拟评分(VAS),关节功能采用美国加州大学肩关节功能评分系统(UCLA)以及美国肩肘协会评分系统(ASES)评价。结果两组术后切口均Ⅰ期愈合,无手术早期相关并发症发生。两组患者均获随访,其中冻结肩组随访时间为13~31个月,平均19.2个月;非冻结肩组为12~33个月,平均20.3个月;两组随访时间比较,差异无统计学意义(t=–0.573,P=0.570)。冻结肩组术前VAS评分高于非冻结肩组(t=–2.166,P=0.037);术后3、6、12个月及末次随访时,两组间比较差异无统计学意义(P0.05)。冻结肩组术前及术后3个月肩关节活动范围(肩外旋及前屈)低于非冻结肩组(P0.05),术后6、12个月及末次随访时组间比较差异无统计学意义(P0.05)。末次随访时两组患者内旋均超过L3。两组术后UCLA、ASES评分均较术前明显改善(P0.05)。其中冻结肩组术前UCLA评分低于非冻结肩组(P=0.037),但末次随访时两组比较差异无统计学意义(P=0.786)。两组手术前后ASES评分比较差异均无统计学意义(P0.05)。结论一期手法松解联合关节镜下清理肩袖修补术治疗肩袖撕裂合并冻结肩,早期疗效略差于肩袖撕裂不合并冻结肩,但6个月后可获得相似疗效。     

经冈上肌入路全关节镜下松解治疗重度原发性冻结肩的疗效观察

目的探讨经冈上肌入路全关节镜下松解治疗重度原发性冻结肩的临床效果。方法将2012年6月—2015年1月收治并符合标准的28例重度原发性冻结肩患者纳入研究。男8例,女20例;年龄42~81岁,平均57岁。均为单肩发作,其中左侧16例,右侧12例。病程7~21个月,平均11个月。合并糖尿病6例。手术均经冈上肌入路后,进行关节镜下松解。术前及术后6周、24个月检查肩关节被动外展、前屈、内收位外旋活动度以及被动内旋情况,采用疼痛视觉模拟评分(VAS)以及美国肩肘外科协会(ASES)评分评价肩关节疼痛及功能情况。结果术后切口均Ⅰ期愈合,无感染、肩关节不稳、神经损伤等并发症发生;患者均获随访24个月。术后患者肩关节疼痛显著缓解,6周及24个月VAS评分均显著低于术前(P0.05),术后24个月VAS评分较术后6周进一步降低(P0.05)。术后6周及24个月,患者肩关节被动外展、前屈、内收位外旋活动度以及ASES评分均较术前显著提高(P0.05);术后6周及24个月间比较,ASES评分及被动前屈、内收位外旋活动度差异有统计学意义(P0.05),被动外展活动度差异无统计学意义(P0.05)。术前被动内旋达股骨大粗隆9例、臀区6例、骶骨7例、L4水平6例,术后6周及24周恢复至T12~T6水平,与健侧相当。结论对于重度原发性冻结肩患者,采用经冈上肌入路能顺利进入盂肱关节,精准定位后方入路,有效保障了全关节镜下松解的实施。     

关节镜下治疗肱骨近端骨折内固定术后冻结肩

目的探讨肩关节镜下治疗肱骨近端骨折术后冻结肩的疗效。方法对61例肱骨近端骨折切开复位内固定术后冻结肩患者采用全身麻醉肩关节镜下治疗联合关节松解、内固定装置取除术。比较手术前后肩关节活动范围、UCLA评分及ASES评分。结果关节镜下肱骨近端骨折内固定术后冻结肩常见有关节内病变。52例完成术后12~18个月的随访,9例失访。52例肩关节活动度、UCLA评分和ASES评分末次随访均较术前改善(P<0.05)。结论肩关节镜下治疗联合关节松解、内固定装置取除术有助于改善肱骨近端骨折内固定术后冻结肩患者的肩关节功能。     

肩关节镜松解术联合关节腔内几丁糖注射治疗原发性冻结肩

[目的]比较关节腔内注射医用几丁糖联合肩关节镜下松解术与单纯肩关节镜下松解术治疗原发性冻结肩的临床疗效。[方法]选取2014年6月～2015年12月本院收治的原发性冻结肩患者46例,均采用肩关节镜下行松解术,根据关节腔内是否注射医用几丁糖将患者分为两组,其中23例患者接受关节镜松解术联合几丁糖关节腔内注射治疗(几丁糖组);另外23例患者仅接受单纯关节镜松解术治疗,未行几丁糖关节腔内注射(非几丁糖组),比较两组术后肩关节疼痛视觉模拟评分(VAS)、美国肩肘外科医师协会(ASES)肩关节功能评分和UCLA肩关节功能评分等评估指标。[结果] 46例患者均顺利完成肩关节镜下松解术。术后1个月随访时,几丁糖组和非几丁糖组患者术后VAS评分、ASES评分、UCLA评分均较术前明显改善,差异有统计学意义(P0.05)。两组间比较丁糖组VAS评分、ASES评分及UCLA评分均优于非几丁糖组,差异具有统计学意义(P0.05);术后1年时,两组间VAS评分、ASES评分及UCLA评分差异均无统计学意义(P0.05)。[结论]肩关节镜下松解术治疗冻结肩可显著提高术后肩关节功能,术中及术后多次联合关节腔内注射医用几丁糖可在一定程度上提高冻结肩短期治疗效果。     

关节镜下改良弹性固定Latarjet术治疗一例慢性锁定性肩关节前脱位

目的总结关节镜下改良弹性固定Latarjet术治疗1例慢性锁定性肩关节前脱位的经验。方法 2016年7月收治1例因摔伤致右肩疼痛、畸形、活动受限8周的49岁男性患者。伤后曾于外院行肩关节复位,未成功。术前美国肩肘外科协会(ASES)评分22分,肩关节功能Constant-Murley评分37分,疼痛视觉模拟评分(VAS)8分。影像学检查示右肩关节锁定性前脱位、肩袖损伤、Hill-Sachs损伤。术前诊断右肩关节慢性锁定性前脱位伴肩袖损伤。全关节镜下彻底松解关节盂、肱骨头、肩胛下肌腱周围及肱三头肌止点软组织,关节复位后以改良双袢法弹性固定Latarjet术。结果术后切口Ⅰ期愈合,无重要血管及神经损伤等并发症发生。患者获随访24个月。影像学复查示盂肱关节恢复正常对位关系,无脱位复发。右肩关节功能恢复正常,24个月时ASES评分及Constant-Murley评分均为94分。结论关节镜下改良弹性固定Latarjet术治疗慢性锁定性肩关节前脱位疗效满意。     

肩关节镜下三联松解术结合自控镇痛治疗顽固性冻结肩

[目的]探讨肩关节镜下三联松解术结合患者自控镇痛(PCA,patient controlled analgesia)治疗顽固性冻结肩的可行性和疗效。[方法]2010年1月²011年8月收治45例顽固性冻结肩患者,男20例,女25例;年龄(58±7.1)岁,术前规范保守治疗效果差。所有患者接受肩关节镜下三联松解术,包括肩胛下肌腱270°解放术、关节囊-盂唇-韧带复合体360°松解术、扩大的肩峰下清理减压术,术后结合个体化的PCA镇痛进行功能康复。随访25.6个月(242011年8月收治45例顽固性冻结肩患者,男20例,女25例;年龄(58±7.1)岁,术前规范保守治疗效果差。所有患者接受肩关节镜下三联松解术,包括肩胛下肌腱270°解放术、关节囊-盂唇-韧带复合体360°松解术、扩大的肩峰下清理减压术,术后结合个体化的PCA镇痛进行功能康复。随访25.6个月(24³7个月),对肩关节活动度、ASES评分、VAS疼痛评分进行比较。[结果]以患者术前、术后3、12、24个月为随访节点,患肩ASES评分分别为(42±17.1)、(87±20.5)、(92±17.7)、(93±9.7)分;患肩主动活动度(前屈上举/外展/体侧外旋/体侧内旋)分别为59.4°±10.5°/40.2°±9.3°/2.3°±14.5°/臀部、153.2°±11.8°/149.4°±8.6°/44.5°±7.3°/T12、167.5°±11.6°/160.6°±7.7°/49.5°±13.3°/T7、169.5°±9.6°/162.6°±7.9°/50.4°±10.2°/T7;患肩VAS疼痛评分分别为6.7±4.5、3.5±7.2、1.4±3.1、1.2±1.8。与术前相比,所有患者在术后12、24个月的肩关节活动度、ASES评分、VAS评分均有明显改善(P<0.01)。患肩无继发性关节不稳定,无血管神经损伤。[结论]肩关节镜下三联松解术松解步骤较清晰,松解范围较彻底,结合个体化的自控镇痛康复训练,可显著改善关节活动度,有效缓解疼痛,恢复功能。手术指证把握得当有助于提高疗效。     

关节镜下双后入路结合前方入路盂肱关节囊松解治疗重度原发性冻结肩

目的研究肩关节镜双后入路结合前方入路盂肱关节囊松解治疗重度原发性冻结肩的临床效果。 方法2013年1月至2016年12月南京中医药大学附属医院对16例重度原发性冻结肩患者行关节镜下双后入路结合前方入路盂肱关节囊松解术,男2例、女14例,平均年龄46.6岁,左肩4例、右肩12例。所有患者术前均拍摄肩关节正位片、冈上肌出口位X线片和肩关节MRI检查,全部患者均行双后入路关节镜下盂肱关节囊松解术,所有病例均同时行肩峰下滑囊清理术,分别在术前和末次随访时采用视觉模拟评分（visual analogue scale,VAS）、Constant-Murley评分和美国加利福尼亚大学（University of California, Los Angeles,UCLA）肩关节评分标准进行评价。 结果随访时间10~37个月,平均26个月。术前、术后即刻和末次随访平均UCLA评分分别为（10.3±3.2）分、（28.2±3.3）分和（31.2±5.3）分,差异有统计学意义（P<0.01）;平均Constant-Murley评分为（38.3±4.2）分、（89.2±4.5）分和（95.2±3.3）分;VAS评分平均为（6.3±1.9）分、（1.3±0.3）分和（1.0±0.2）分（P<0.01）。所有患者均对手术效果表示满意。 结论关节镜下双后入路结合前方入路盂肱关节囊松解治疗重度原发性冻结肩,便于术中操作,可以显著地缓解疼痛、恢复肩关节功能。关节镜下双后入路结合前方入路盂肱关节囊松解为治疗重度原发性冻结肩提供有效方法。     

关节镜下手术松解治疗肩周炎的临床研究

目的 探讨关节镜下手术松解治疗肩周炎关节僵硬的临床效果.方法 2000年7月至2006年4月,对20例肩周炎关节僵硬的患者,其中10例为特发性肩周炎,10例为创伤性肩周炎,采用关节镜下手术选择性松解旋转肌袖间隙、盂肱韧带、关节囊和肩峰下间隙等进行治疗.并用VAS(visual analog pain scale)疼痛评分系统和改良美国肩肘关节外科协会评分系统((modified american shoulder and elbow society score,MASES)进行疗效评价.结果 全部患者获得13～73个月(平均28.1个月)的随访.术后肩关节活动度、VAS和MASES评分均较术前明显改善(P＜0.01),优7例,良10例,一般3例,优良率为85%,未发生任何手术并发症.特发性肩周炎患者在肩关节外展活动度、VAS和MASES评分的改善方面均优于创伤性肩周炎,两组差异有统计学意义(P＜0.01、P＜0.05和P＜0.01).结论 关节镜下松解术是治疗肩周炎关节僵硬的首选方法.肩周炎的手术疗效不但与病因有关,还与术前肩关节僵硬的程度有关.     

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.     

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.     

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.