输尿管软镜钬激光碎石术治疗体外冲击波碎石术失败的输尿管上段结石

目的:评价输尿管软镜钬激光碎石术治疗体外冲击波碎石术(ESWL)失败的输尿管上段结石的疗效。方法:回顾性分析2013年6月～2017年6月我院采用输尿管软镜钬激光碎石术治疗ESWL失败的输尿管上段结石48例。结石最大直径为0.6～1.5 cm。手术方法首先将结石推入肾脏内,然后沿导丝直接置入纤维输尿管软镜到达肾盂,找到结石以200μm光纤和16 W功率钬激光碎石。结果:46例患者顺利一次性完成手术,手术成功率为95.83%。术后4周拔除双J管,2个月后复查B超和或平扫CT。37例结石全部排尽;7例复查有2～4 mm的小结石,无需再次行ESWL;2例残留结石直径4 mm,但未接受进一步治疗。所有患者无输尿管穿孔及大出血等并发症发生。结论:输尿管软镜钬激光碎石术治疗ESWL失败的输尿管上段结石可安全有效地清除结石,尤其适用于结石体积较小和无明显肾积水的结石。可作为输尿管上段结石ESWL失败后的一种有效补救性治疗措施。     

输尿管镜钬激光碎石术治疗体外冲击波碎石失败的输尿管结石89例报告

目的探讨输尿管镜钬激光碎石术治疗体外冲击波碎石(extracorporeal shock-wave lithotripsy,ESWL)失败的输尿管结石的临床效果。方法应用输尿管镜钬激光碎石术治疗ESWL失败的输尿管结石89例。69例合并息肉或被肉芽组织包裹,同时钬激光消融息肉;合并结石远端输尿管狭窄4例,开放手术切除狭窄段。结果一次碎石成功81例,成功率91%。1周内结石排净67例,其余14例2周内结石排净。4例结石被冲入肾盂,术后2周经ESWL后排出;4例输尿管镜置入失败,经开放手术治愈。结论输尿管镜钬激光碎石具有安全高效性,可作为ESWL治疗失败的输尿管结石首选治疗方法。     

输尿管结石ESWL失败改腔内钬激光碎石术的疗效观察

目的 探讨输尿管结石ESWL失败后采用腔内钬激光碎石术的临床疗效。方法 自2001年10月至2002年8月，对28例输尿管结石(ESWL失败)行输尿管镜下钬激光碎石术。结果 26例经输尿管镜下钬激光碎石术治愈，治愈率92．8％(26／28)；1例结石上移，辅以ESWL治愈；1例因输尿管纤维性扭曲改开放手术。结论 输尿管镜下钬激光碎石术安全、有效、方便，可以作为输尿管结石的首选治疗。     

钬激光治疗ESWL失败的输尿管上段结石78例分析

目的探讨输尿管镜钬激光碎石术治疗体外冲击波碎石（extracorporeal shockwave lithotripsy,ESWL）失败的输尿管上段结石的临床效果。方法回顾性分析应用输尿管镜钬激光碎石术治疗ESWL失败的输尿管上段结石78例患者资料。结果输尿管上段结石并发炎性息肉者67例（86%）,碎石同时钬激光消融息肉。有输尿管扭曲、狭窄者16例（21%）。一次碎石成功63例,成功率81%。1周内结石排净46例,其余17例4周内结石排净。无输尿管穿孔、撕脱等严重并发症。11例结石冲回肾盂,经EWSL或经皮肾镜钬激光碎石术成功。4例置镜失败,行开放手术治愈。结论输尿管镜钬激光碎石安全有效,可作为ESWL治疗失败的输尿管上段结石首选治疗方法。     

输尿管镜钬激光治疗ESWL失败输尿管结石85例

目的探讨经输尿管镜钬激光碎石治疗体外冲击波碎石（ESWL）失败的输尿管结石的临床效果。方法采用经输尿管镜钬激光碎石治疗ESWL失败的输尿管结石85例，总结其临床资料。结果85例中23例合并输尿管狭窄，64例有肉芽组织包裹。2例进镜失败改开放手术；83例碎石成功，2周结石排净率97．6％。结论经输尿管镜钬激光碎石治疗ESWL失败的输尿管结石效果理想，创伤小、并发症少，可以作为首选。     

钬激光碎石术治疗复杂性输尿管结石（附87例报告）

目的探讨复杂性输尿管结石经钬激光腔内治疗的有效性及安全性。方法回顾性分析2003年12月～2005年5月收治的经输尿管镜钬激光治疗复杂性输尿管结石87例的临床资料。87例均伴有患侧轻～中度肾盂积水，其中46例合并结石远端输尿管狭窄，69例合并有息肉或肉芽组织包裹，21例为ESWL治疗失败后。结果87例中83例单次手术碎石成功，单次手术结石粉碎率达95．4％（83／87），2例结石在钬激光碎石过程中移位于肾盏，术后再行ESWL治疗；1例进镜时输尿管穿孔，1例术中退镜时输尿管黏膜撕脱改为开放手术。结论输尿管镜下钬激光碎石术治疗复杂性输尿管结石安全、有效，尤其适用于体外冲击波碎石效果不佳的患者。     

钬激光碎石术治疗复杂性输尿管结石87例报告

目的：探讨复杂性输尿管结石经钬激光腔内治疗的有效性及安全性。方法：回顾性分析2003年12月-2004年12月收治的经输尿管镜钬激光治疗复杂性输尿管结石87例患者的临床资料。87例均伴有患侧轻～中度肾孟积水,其中46例合并结石远端输尿管狭窄,69例合并息肉或肉芽组织包裹,21例为ESWL治疗失败后。结果：87例中,83例单次手术碎石成功,单次手术结石粉碎率达95．4％（83／87）,2例结石在钬激光碎石过程中移位于肾盏,术后再行ESWL治疗;1例进镜时输尿管穿孔,1例术中退镜时输尿管黏膜撕脱改为开放手术。结论：输尿管镜下钬激光碎石术治疗复杂性输尿管结石安全、有效,尤其适用于ESWL治疗效果不佳的患者。     

输尿管结石ESWL原位治疗失败的原因与对策(附16例分析)

目的探讨ESWL原位治疗输尿管结石失败的原因与处理措施。方法与结果分析16例输尿管结石ESWL原位治疗失败的临床资料。16例中,8例改输尿管切开取石术,6例改输尿管镜下钬激光碎石术,2例改钬激光术后因少量碎石滑至肾脏又补充行ESWL治疗,均治愈。术中证实输尿管炎性狭窄6例,息肉2例,肉芽组织包裹2例。结论ESWL治疗输尿管结石疗效可靠,但要正确掌握好适应证。若病程长,肾积水严重,患肾功能差,或结石结构致密,且面积大,则不宜选择ESWL术。ESWL治疗失败后,输尿管上段结石首选输尿管切开取石术,输尿管下段结石首选输尿管镜下钬激光碎石术。     

输尿管镜钬激光联合两重双J管引流术处理ESWL治疗失败的输尿管结石

目的：评价输尿管镜钬激光碎石联合腔内两重双J管引流术处理ESWL治疗失败输尿管结石的临床疗效,并探讨其影响因素。方法：2005年1月～2010年6月对ESWL失败的21例输尿管结石患者行输尿管镜钬激光碎石术,碎石后置入两根双J管,术后常规留置2～4周后拔除。结石合并息肉形成的13例患者均同期采用钬激光汽化切割息肉。结果：21例输尿管结石行钬激光碎石成功率达95．2%（20／21）,手术时间10～70min,平均（40．4±10．3）min;术后住院时间1～7天,平均（3．1土1．2）天。结论：输尿管镜钬激光碎石联合腔内两重双J管引流术处理ESWL治疗失败输尿管结石是安全可行的,保证结石清除率的同时不增加并发症发生率。     

输尿管镜钬激光碎石术治疗输尿管上段结石52例报告

目的:探讨输尿管镜钬激光碎石术治疗输尿管上段结石的临床效果.方法:采用输尿管镜下钬激光碎石术治疗输尿管上段结石患者52例,其中双侧输尿管上段结石2例,共计左侧30例侧,右侧24例侧.结石大小(0.4～1.7)cm×(0.6～2.0)cm.结果:手术成功率98.1%,平均手术时间约28 min(17～65 min).1例侧因输尿管口狭窄进镜困难改行开放手术.术后1个月复查,一次性碎石排净率为90.6%,5例侧有结石残留患者保留双J管行ESWL治疗,结石排出.术后3个月复查,所有患者患侧肾积水均明显减轻.结论:在熟练掌握输尿管镜操作技术的前提下,采用输尿管镜钬激光治疗输尿管上段结石是一种安全、有效的方法.     

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.     

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.