输尿管镜气压弹道碎石术在梗阻性急性肾衰中的应用

目的探讨输尿管镜腔内气压弹道碎石术治疗上尿路结石所致梗阻性急性肾功能衰竭的可行性及疗效. 方法采用输尿管镜腔内气压弹道碎石术治疗由输尿管结石梗阻导致急性肾功能衰竭32例. 结果 32例均迅速解除梗阻,肾功能有效恢复.术后患者即进入多尿期,平均持续5(3～10)d.BUN 1周后平均达6.7(4.8～8.9)mmol/L,Cr 1月后达117(65～170)μmol/L. 结论输尿管镜气压弹道碎石术能迅速消除上尿路结石梗阻所致的急性肾功能衰竭,具有安全、高效、创伤小、术后恢复快的特点,同时可诊断及治疗输尿管阴性结石.     

输尿管镜气压弹道碎石术治疗上尿路结石梗阻性急性肾功能衰竭

目的探讨输尿管镜气压弹道碎石术治疗上尿路结石梗阻性急性肾功能衰竭的疗效。方法2002年8月-2006年4月我院对9例（14侧）上尿路结石梗阻性急性肾功能衰竭（血Cr〉443μmol／L）急诊行输尿管镜探查，气压弹道碎石。到达结石处后，使用瑞士EMS气压弹道碎石机击碎并取出结石，对于较大或碎石困难的结石，不求取净结石，快速打通输尿管腔，留置双J管引流。结果9例14侧均一次性打通输尿管腔，留置双J管。7例12侧输尿管结石一次取净；2例2侧肾盂残留少量结石，其中1例口服排石药后自行排出，1例体外冲击波碎石后自行排出。9例未出现输尿管撕脱、断裂、穿孔等严重并发症。9例血cr术后3—7d降至正常，肉眼血尿术后1-4d消失。9例术后3—7d，平均5d出院。双J管术后1-2个月拔除。7例随访2—30个月，平均14个月，血Cr正常，B超或KUB平片无泌尿系结石复发。结论对于上尿路结石梗阻性急性肾功能衰竭的患者，急诊输尿管镜下碎石，疗效确切，创伤小，可同时处理双侧输尿管结石。     

输尿管镜碎石治疗结石梗阻性急性肾功能衰竭的循证护理

目的:探讨循证护理在经尿道输尿管镜直视下钬激光碎石或气压弹道碎石治疗结石梗阻性急性肾功能衰竭的的作用.方法:对16例(20侧)上尿路结石并发急性肾功能衰竭患者采用急诊输尿管镜下钬激光碎石、输尿管放置双J管手术进行循证护理.包括健康指导、心理护理、各种引流管道管理、用药指导、排石指导、预防感染和出院指导.结果:所有病人接受手术及术前术后护理,患者全部治愈出院,无一例死亡及严重并发症.结论:循证护理明显提高输尿管镜碎石治疗结石梗阻性急性肾功能衰竭的护理质量,经尿道输尿管镜钦激光碎石取石术是一种便捷、安全、有效的治疗输尿管结石梗阻导致急性肾功能衰竭的方法.     

输尿管镜治疗输尿管结石梗阻并发急性肾功能衰竭

目的:探讨治疗上尿路结石性梗阻并发急性肾功能衰竭的方法。方法:用输尿管镜直视下气压弹道碎石术治疗输尿管结石梗阻并急性肾功能衰竭患者18例。结果:术后患者血清BUN、Cr均恢复正常或接近正常,尿量恢复。结论:输尿管镜诊治上尿路结石性梗阻并发急性肾功能衰竭,具有安全、疗效可靠、损伤小等优点,能同时处理双侧输尿管病变,可作为首选治疗方法。     

输尿管镜气压弹道碎石术治疗输尿管结石梗阻并发急性肾功能衰竭(附15例报告)

目的:分析15例输尿管结石致急性肾功能衰竭患者的急诊输尿管镜腔内碎石方法,探讨输尿管镜气压弹道碎石术治疗输尿管结石梗阻并发急性肾功能衰竭的临床疗效。方法:硬膜外阻滞麻醉,采用输尿管硬镜,在电视监视下,经尿道插入膀胱和输尿管,气压弹道碎石探杆将结石击碎。结果:15例碎石均获成功。13例术后3天肾功能复查正常;1例并发重度贫血者,术后2周血Cr168μmol/L;另1例并发糖尿病者术后出现持续高热,腰痛,有严重肾脏感染,感染控制后肾功能未明显好转而行血液透析治疗。结论:输尿管镜下气压弹道碎石术治疗输尿管结石并发急性肾功能衰竭安全、有效,对并发感染、慢性肾功能不全等基础疾病者,术后肾功能恢复程度及可能出现的并发症仍应予以重视。     

输尿管镜在上尿路结石性梗阻肾衰中的临床应用(附11例报告)

目的：探讨上尿路结石性梗阻并发急性肾功能衰竭的治疗方法。方法：应用输尿管镜直视下气压弹道碎石术治疗输尿管结石梗阻并急性肾功能衰竭11例。结果：术后患者血清BUN、Cr均恢复正常或接近正常，尿量恢复，结石排净率90％（18／20）。结论；输尿管镜诊治上尿路结石性梗阻并发急性肾功能衰竭，具有安全、疗效可靠、损伤小的优点，能同时处理双侧输尿管病变，可作为首选治疗方法。     

输尿管镜气压弹道碎石术治疗输尿管结石

目的：探讨输尿管镜气压弹道碎石术治疗输尿管结石的疗效。方法：采用输尿管镜气压弹道碎石术治疗输尿管结石患者128例，其中5例为ESWL后输尿管石街形成，6例并发急性梗阻性肾功能不全。结果：128例中，一次性碎石成功117例，占91．4％。碎石失败11例，占8．6％，其中6例输尿管上段结石移位至肾盂，留置双J管后行ESWL治愈，另外2例输尿管穿孔和3例进镜失败患者均立即改行开放手术治愈。6例并发急性梗阻性肾功能不全患者碎石术后即进入多尿期，2周后复查肾功能恢复正常。结论：输尿管镜气压弹道碎石术治疗输尿管结石具有微创、安全、效果好等优点，可作为输尿管中、下段结石的首选治疗方法。     

输尿管镜治疗结石引起的急性梗阻性肾功能衰竭

目的：探讨急诊应用输尿管镜治疗上尿路结石引起急性梗阻性肾功能衰竭的价值。方法对123例双侧上尿路结石梗阻导致急性肾功能衰竭患者均经输尿管镜下探查、气压弹道碎石取石、置管及经皮肾造瘘引流等微创治疗。结果100例（81．3％）术后2～10天BUN、Cr降至正常；22例术后10～15天Cr仍在188.6～232.3iμmol／L，1例因一侧先天独肾对侧输尿管结石慢性梗阻引起肾功能衰竭，术后3天血液透析1次，术后15天Cr810μmol／L，出院2个月Cr正常。4例因一侧肾切除或一侧先天独肾等对侧肾功能差，3个月复查仍处于氮质血症期。结论：使用输尿管镜急诊治疗结石梗阻性肾功能衰竭能及时解除梗阻，有效保护肾功能，损伤小，并发症少，操作简单，可以作为首选方法使用。     

腔内气压弹道碎石治疗双侧输尿管结石致肾后性肾衰25例

目的　探讨双侧输尿管结石致肾后性肾功能衰竭的治疗措施。方法　对 2 5例双侧输尿管结石致肾后性肾功能衰竭患者采用经输尿管镜气压弹道碎石术治疗 ,回顾性分析其治疗效果。结果　 2 5例患者碎石均获成功 ,2 4例痊愈出院 ,1例仍有氮质血症。 1例出现肉眼血尿 ,2d后自然消失 ,无尿瘘、输尿管穿孔等并发症。结论　经输尿管镜气压弹道碎石术是治疗双侧输尿管结石致肾后性肾功能衰竭比较理想和简单的治疗方法。     

孤立肾上尿路结石致梗阻性肾功能衰竭的1输尿管镜治疗

目的探讨输尿管镜下气压弹道碎石术治疗孤立肾上尿路结石所致梗阻性急性肾功能衰竭的安全性与有效性。方法采用输尿管镜下气压弹道碎石术治疗孤立肾并发输尿管结石致梗阻性急性肾功能衰竭15例。男6例，女9例。年龄23～72岁，平均40岁。输尿管上段结石6例，中下段结石9例。结石大小0．5cm×1．0cm～0．8cm×1．5cm，平均0．7cm×1．3cm。梗阻时间2～5d。血尿素氮（BUN）15．3～26．5mmol／L，平均19．3mmol／L；血肌酐（SCr）450～1600μmol／L，平均780μmol／L。结果15例手术均一次成功，均留置双J管。术后1周，12例患者结石排净，8例患者BUN和SCr恢复正常或接近正常。术后1个月，14例患者结石排净，1例因部分结石移至肾盂，加行体外冲击波碎石术（ESWL）治疗，2周后残石排净；10例患者BUN和SCr恢复正常或接近正常，BUN5．6～10．8mmol／L，SCr69～110μmol／L。5例病史较长者至术后6个月时肾功能仍未完全恢复正常，BUN12．6～15．8mmol／L，SCr160～290μmol／L。15例均未发生术中、术后并发症。结论输尿管镜下气压弹道碎石术治疗孤立肾上尿路结石致急性肾功能衰竭安全、有效。     

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.