脉冲电刺激促进周围神经再生的应用

目的探讨脉冲直流电刺激治疗周围神经损伤的疗效。方法应用直流脉冲电刺激仪针对周围神经损伤的病人进行电刺激治疗,通过随访观察３－６个月后神经功功能恢复情况。结果本组１２８例闭合性周围神经损伤及神经修复后的病人,经６０－１２０ｄ治疗,肌力皮肤感觉均取得满意效果。结论直流脉冲电能够提高神经肌肉的兴奋性,促进周围神经的再生,在闭合性神经损伤的观察,应用电刺激治疗,可观察神经的传导功能,为手术适应证的选择和预     

经皮电刺激促进周围神经再生的临床应用

目的观察电刺激对臂丛神经、桡神经损伤是否具有促进神经再生的作用。方法选择１９９３年１月～１９９６年１２月收治的臂丛神经损伤７６例、桡神经不完全损伤１７例，随机分为电刺激治疗组和对照组。电刺激组进行经皮电刺激治疗６个月，对照组则不作经皮电刺激治疗。电刺激６个月后观察肌皮神经、肩胛上神经及桡神经的功能恢复情况。结果肘关节屈曲度数、伸腕肌力，电刺激组均优于对照组（Ｐ＜０．０５）。结论经皮电刺激能促进周围神经的再生，可应用于宜保守治疗的周围神经损伤及神经修复后的辅助治疗。     

经皮电刺激促进腓总神经损伤后神经再生的临床研究

目的证实经皮电刺激对周围神经(本文选择腓总神经)完全损伤后神经再生的促进作用,并探讨最佳的电刺激的参数、波形优化组合等治疗方案。方法对30例腓总神经完全损伤患者,随机分为电刺激组和对照组,每组15例,在行神经缝合术后,各组同时服用神经营养药物治疗,电刺激组在术后4周石膏拆除后加用电刺激治疗。经过方波和变频波的交替使用,之后均使用变幅脉冲波+肌肉训练波,并适度增加肌肉训练波的治疗时间。术后随访内容:术后6个月进行足趾伸屈力,神经电生理检测。结果电刺激组的临床肌力与肌电图结果均优于对照组,两组差异有统计学意义(P<0.05)。电刺激组的肌力恢复时间与肌电图恢复时间也明显短于对照组,两组差异有统计学意义(P<0.05)。结论经皮电刺激治疗具有促进受损周围神经再生和传导功能恢复的作用,并且能减少受损骨骼肌的萎缩,尤其对电刺激仪的工作参数、电流波形进行优化组合后,可获得更好的疗效。     

经皮电刺激促进周围神经再生的实验研究

为了观察经皮电刺激能否促进周围神经再生，选用３６只大鼠坐骨神经，切断后的神经断端吻合与钳夹损伤后的神经干瘢痕模型，通过参数为２～５Ｈｚ，０．４ｍｓ，２４～４８Ｖ的经皮电刺激，分别于术后１～６周，进行电生理组织形态学观察。结果显示：电刺激组的神经传导速度、肌肉最大诱发电位波幅、神经纤维生长速度、吻合口轴突通过率、肌纤维截面积及肌重均优于同期对照侧。表明经皮电刺激能促进周围神经再生。     

经颅磁刺激和局部电刺激促进周围神经再生的组织学研究

目的　研究和比较经颅磁刺激和局部电刺激促进周围神经再生的组织学变化。方法　建立 2 0只大鼠坐骨神经损伤模型后 ,分别用经颅磁刺激动物头颅正上方 2cm处 (相当于运动皮层 ,为经颅磁刺激组 ) ,和直流点送电刺激坐骨神经缝合口近端 (局部电刺激组 )。刺激 2 0min·d-1× 2 0d ;每组 10只大鼠。术后 2 0d取材 ,观察 2组新生神经的形态学变化和有髓神经纤维数目。结果　电刺激组可见许多新生有髓神经纤维 ,但同时可见到有神经纤维髓鞘的退变现象。磁刺激组则有大量新生有髓神经纤维 ,髓鞘较薄但结构完整 ,板层清晰。经颅磁刺激组再生神经纤维的数目明显多于电刺激组 (P <0 0 5 )。结论　经颅磁刺激促进受损周围神经再生和恢复传导功能的作用优于局部电刺激。     

术中超强电刺激在周围神经损伤治疗中的应用

为了探索术中应用超强电刺激方法，能否提高手术治疗周围神经损伤的效果，１９９４年７月～１９９５年５月对１６例周围神经不全损伤或修复手术后神经再生不良患者，再手术时在术中持续肌电监测下进行神经松解术，并给予超强肌电刺激，分别测定超强电刺激前后潜伏期、波幅，以及比较其改善程度。结果发现，经超强电刺激前后肌电监测的结果，显示各相应神经之潜伏期及波幅均有改善。术后随访，神经所支配的相应肌肉功能均有提高。证明，超强电刺激为一种提高周围神经损伤疗效的好方法。     

经皮电刺激促进桡神经损伤后神经再生的临床研究

目的 探讨经皮电刺激对上臂桡神经完全损伤后神经再生的促进作用,并对电刺激的参数、波形进行优化组合,以寻求最佳治疗方案.方法 对28例上臂段桡神经完全损伤患者,随机分为电刺激组和对照组,每组14例,在行桡神经缝合术后,各组同时服用神经营养药物治疗,电刺激组在术后4～6周石膏拆除后加用电刺激治疗.第1个月使用方波治疗,脉冲频率为2 Hz;第2个月使用变幅脉冲波治疗,脉冲频率为15 Hz;第3个月起继续使用变幅脉冲波治疗,脉冲频率为15Hz,同时每次附加肌肉训练波,脉冲频率为60 Hz;之后均使用变幅脉冲波+肌肉训练波,并适度增加肌肉训练波的治疗时间.术后随访内容:伸腕、伸指肌力,神经电生理检测.结果 电刺激组的临床伸腕、伸指肌力与肌电图结果均优于对照组,两组差异有统计学意义(P＜0.05).电刺激组的肌力恢复时间与肌电图恢复时间也明显短于对照组,两组差异有统计学意义(P＜0.05).结论 经皮电刺激治疗对促进上臂段桡神经损伤后神经再生的效果明显,在对电刺激仪的工作参数、电流波形进行优化组合后,可获得良好的疗效.     

神经肌肉电刺激治疗周围神经损伤的研究进展

目的综述国内外应用神经肌肉电刺激(neurom uscular electrical stimulation,NMES)治疗周围神经损伤的机制、参数选择、临床应用等研究进展。方法检索近年来NMES治疗周围神经损伤的国内外相关文献,综述分析相关研究进展。结果NMES治疗周围神经损伤应在个体化参数、合适刺激方式下早期应用,具有促进神经再生、预防肌肉萎缩的作用。结论NMES临床应用安全、有效,植入式电刺激有望成为治疗神经断裂伤的较佳选择。     

脉冲电磁场对带血供周围神经移植修复脊髓损伤的作用

目的：探讨脉冲电磁场对带血供周围神经移植修复脊髓损伤的作用。方法：将４０只雌性Ｗｉｓｔａｒ成年鼠分为Ａ、Ｂ２组,Ａ组为单纯用带血供的正中神经移植修复脊髓损伤,Ｂ组为带血供正中神经移植后给予脉冲电磁场治疗,术后６０ｄ进行大体、组织学（光、电镜）观察、电生理检测及移植神经内再生轴突形态计量分析。结果：在组织学,神经传于单纯带血供周围神经移植的Ａ组。结论：带血供周围神经是修复脊髓损伤较为理想的移植材料,     

应用轴索修复技术治疗周围神经损伤的疗效分析

目的 评价轴索修复技术治疗周围神经损伤的临床疗效及应用前景。方法 采用特制保护液浸泡、液氮冷冻及断面修整、粘合与固定等轴索修复技术 ,对 12例周围神经 (13根神经 )损伤的患者进行轴索水平的修复,术后平均随访 9.7个月。结果 12例中, 4例行一期健侧 C 7移位术,术后 4～ 7个月神经再生达患侧胸锁关节或腋部,具备了二期行尺神经转位手术的条件; 5例行副神经移位于肩胛上神经,其中 3例术后 16个月冈上肌与冈下肌肌力达 3～ 4级 (按照 6级分类法 ), 2例术后 12个月神经功能有不同程度恢复; 1例行二期健侧 C 7移位手术 (尺神经移至正中神经 ),术后 4个月桡侧腕屈肌肌电图示神经再生; 1例行膈神经移位于肌皮神经,术后 15个月肌电图示神经再生; 1例行指神经修复,术后 3个月恢复保护性感觉。结论 轴索修复技术是一种有效的周围神经修复方法,具有一定的临床应用前景。     

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.