肾窦内肾盂加肾实质切开治疗复杂性肾结石

目的探讨复杂性肾结石手术取石方法。方法对58例复杂性肾结石患者，采用肾窦内肾盂加肾实质切开取石术。结果全部病例均取出结石，术后肾功能恢复好，小结石残留9例，并发漏尿4例，继发出血1例而行肾切除。结论本术式操作简单、出血少、对肾功能影响小，适合于复杂性肾结石的治疗。     

指间阻断肾血流肾实质切开治疗复杂性肾结石

目的:探讨肾实质切开治疗复杂性肾结石的效果。方法:采用静脉滴注肌苷2.0,指间阻断肾血流肾实质切开治疗复杂性肾结石30例。十二肋缘下切口,游离肾脏,沿Brodel氏线纵行切开肾实质全层,直视下取石,冲洗。用4-0肠线或可吸收缝合线间断缝合肾盂肾盏粘膜,1-0肠线或可吸收缝合线缝合肾实质全层。结果:28例结石一次取净,2例小结石残留,经ESWL(体外冲击波碎石)治愈,1例为肾盂钙化灶。结论:手指间阻断肾血流肾实质切开适合于肾内型肾盂鹿角形(铸形)结石和复杂性肾结石手术治疗。     

肾Brodel线小切口切开取石术治疗鹿角状结石疗效观察(附32例报告)

目的:探讨肾Brodel线小切口切开取石术治疗肾鹿角状结石的疗效.方法:选择肾鹿角状结石患者32例,经患侧11肋间切口分离肾动脉,在低温下阻断肾动脉,取.肾外侧缘Brodel线上切开肾实质至结石,取出结石.结果:低温下肾动脉阻断时间15～32 min,平均19 min手术时间90～180 min,平均140 min;Brodel线切口长4～5 cm;出血量平均120 ml,有6例输血200～400 ml,术后漏尿2例,结石残留3例,经相应处理治愈.术后随访3～12个月,肾功能恢复良好.结论:低温下阻断肾动脉作肾Brodel线小切口取石术是治疗肾鹿角状结石的理想术式,结石取净率高,并发症少,肾功能恢复良好.     

原位低温阻断肾血管肾实质切开取石术

目的探讨原位低温阻断肾血管肾实质切开取石术治疗复杂性肾结石的效果。方法2000年3月～2005年1月采用原位低温阻断肾血管肾实质切开取石术治疗肾内型肾盂复杂性肾结石患者22例,术中快速静脉滴注肌苷2.0g,静滴20%甘露醇250ml。根据术前影像检查结果及术中所见选择肾切口径路:13例充填于各盏的鹿角状结石,行肾背侧Brodt线肾实质肾盏切开取石;5例肾下盏肾盂鹿角状结石,行肾盂肾实质联合切开取石;4例结石过多者,于肾皮质最薄处另作放射状切口取石。结果肾血管阻断时间平均45(30～60)min;手术时间平均110(90～180)min;平均失血量150(80～400)ml。结石一次取净21例,1例残余结石,术后2个月带双J管行ESWL碎石排出。术后1～2月复查肾功能,术前有肾功能损害的8例,血清Cr平均110.2μmol/L,血清BUN平均8.0mmol/L,均明显改善,其余患者肾功能无损害,无严重术后并发症。18例随访6个月～3年无一例复发。结论原位低温阻断肾血管肾实质切开取石术治疗复杂性肾结石安全有效、出血少、结石残留率低。     

低温下肾蒂阻断肾实质切开取石术治疗复杂性肾结石25例报告

目的：探讨低温下肾蒂阻断肾实质切开取石术在复杂性肾结石治疗中的应用。方法：选择复杂性肾结石患者25例，阻断前静脉注射肌苷2．0g，均采用低温下阻断肾蒂，沿Brodel线作肾实质切开取石术。结果：25例肾蒂阻断17～45min，术中出血150～450ml，手术时间100～160mln，结石残留2例。术后随访6个月～4年，术后肾功能恢复良好。结论：低温肾蒂阻断肾实质切开取石术是治疗复杂性肾结石的重要方法，结石取净率高，并发症少，对肾功能无影响。     

肾窦内肾盂切开取石38例临床研究

目的探讨肾窦内肾盂切开治疗复杂性鹿角状或铸状及多发性肾结石疗效。方法沿肾盂外间隙分离肾窦内肾盂，于肾中下1／3下盏上方无血管区用2-0合成可吸收缝线扣锁式全层缝合肾实质2排，其间切开肾实质，由肾上、下盏间作一弧形切口，取出较大的结石，直视下探查取出肾盏内小结石。结果30例结石一次性取净，占80％；8例有1—2粒小结石残留，术中仅2例输血200ml。随访6个月-6年，29例无肾积水，2例结石复发。结论肾窦内肾盂切开取石术具有出血少，不分离肾周脂肪，不阻断肾血流，肾功能受损轻，结石取净率高，无漏尿、易于掌握等优点。是肾内型肾盂内鹿角状或铸状及多发性结石的理想术式。     

4种术式治疗孤立肾复杂性结石比较(附72例报告)

目的探讨治疗孤立肾复杂性结石的适宜手术方式. 方法回顾性分析肾窦内肾盂切开取石术(术式1)、肾盂、肾实质切开取石术(术式2)、无萎缩性肾实质切开取石术(术式3)、肾盂切开气压弹道碎石术(术式4)等4种不同术式治疗72例孤立肾复杂性结石的临床资料,依据手术时间、术后住院天数、住院费用、结石清除率、手术并发症及肾功能改善情况评价其优缺点. 结果术式1、2、3、4中结石清除率分别为93.75%(15/16)、88.23%(15/17)、84.61%(11/13)、96.15%(25/26),输血例数分别为0、6、8、0例;21例肾功能不全患者分别采用术式2、3、4,其手术后肾功能恢复时间分别为3月、3月、2周. 结论肾窦内肾盂切开取石术是治疗孤立肾中小型复杂性结石的基本方法之一,肾盂切开气压弹道碎石术是治疗巨型复杂性孤立肾结石的最佳手术选择.     

肾窦内肾盂及肾后唇实质弧形切开取石术治疗复杂性鹿角形肾结石

目的 探讨肾窦内肾盂及肾后唇实质弧形切开取石术治疗复杂性鹿角形肾结石的疗效。方法 采用自行设计的肾窦内肾盂及肾后唇中下1／3肾实质弧形切开取石术治疗复杂性鹿角形肾结石86例97侧；右侧42例，左侧33例，双侧11例。合并输尿管结石17例，肾上盏、中盏和（或）多发性肾结石54例。肾功能不全25例，BUN12．3～76．0mmol／L，Scr 231～1721μmol／L。术中游离肾窦内肾盂后，2-0可吸收线在肾后唇中下1／3肾实质交界处作两排链扣式缝合肾实质全层，达肾下盏大组开口平面后继续弧形向上部作两排链扣式缝合，经肾中盏大组至其开口平面。沿此切口切开肾实质和肾盂及下中肾盏，边切边缝，用肾盂拉钩拉开肾实质即可取净肾盂、肾盏内结石。结果 86例97侧均一次取净结石。手术时间105～187min、平均129min。术中出血量120～460ml，平均220ml。43例输血．输血量120～200ml，平均140ml。术后1个月复查B超和KUB加IVU未几几残留结石，肾积水减轻，肾盏颈无狭窄。结论 肾窦内肾盂及肾后唇实质弧形切开取石术具有操作简单、安全，术野清晰，出血少，对肾损伤轻，一次性取净肾结石等优点，是治疗复杂性鹿角形肾结石较为理想的方法。     

常温下阻断肾蒂肾切开取石治疗复杂性铸型肾结石

目的 探讨常温下阻断肾蒂肾实质切开取石治疗复杂性铸型肾结石的临床疗效.方法 对20例复杂性铸型肾结石患者均采取常温下阻断肾蒂肾实质或+肾盂切开取石术.手术前、后检查包括腹部平片、静脉尿路造影、CT、B超、尿素氮、肌酐等项目并术后随访.结果 20例患者均顺利完成取石,一次性取净结石17例,结石残余残留率为15％.手术时间...     

肾窦内肾盂加肾后唇切开术治疗鹿角状肾结石

目的探讨肾窦内肾盂加肾后唇切开术治疗鹿角状肾结石的疗效。方法鹿角状肾结石患者40例，单侧36侧，双侧4侧，肾盂均为肾内型，肾实质无明显萎缩，肾功能均正常，均施行肾窦内肾盂加肾后唇中下段无血管区切开取石术。结果本组均在常温下手术，未阻断肾蒂，结石均安全取出，无术中严重并发症发生。平均手术时间115(90～140)min，平均失血量为100(90～120)ml，术后1月拔除双J管，复查3例(7．5％)有肾盂内小结石残留。结论肾窦内肾盂加肾后唇中下段区切开取石术适合肾鹿角状结石的治疗．具有操作较简单、易掌握．取石容易且结石一次性取出率高，出血少的优点。     

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.