彩色超声引导下腔静脉滤器置入术

目的 报道超声引导下腔静脉滤器置入新方式及其对深静脉血栓后肺栓塞的预防作用。方法自2002年5月～2003年1月对9例下肢深静脉血栓形成(其中1例入院时出现肺栓塞)在彩色超声引导下实施下腔静脉滤器置入术，其中5例在滤器置入术后立即实施下肢深静脉取栓术，另外4例行保守治疗。结果本组9例均获成功，随访1月～7月，平均2月，无并发症及肺栓塞发生，曾出现肺栓塞滤器置入后未再发生肺栓塞。结论彩色超声引导下腔静脉滤器置入术可有效地预防深静脉血拴形成后肺栓塞的发生，对不易搬动、危重、肾功能不全和对造影剂过敏的患是最佳的选择，免除了X射线的辐射，安全、方便、经济、易于普及。     

下肢静脉血栓形成后下腔静脉滤网置入预防肺栓塞14例报告

目的探讨数字减影血管造影（digital subtraction angiography，DSA）引导下置入腔静脉滤网对深静脉血栓形成后肺栓塞（pulmonary embolism，PE）的预防作用。方法2003年10月-2004年12月，我院对14例下肢深静脉血栓形成在DSA引导下行下腔静脉滤网置入术，其中12例在滤器置入术后立即行下肢深静脉取栓术，2例保守治疗。结果14例手术均获得成功，手术时问85～115min，平均95min。无并发症。随访1-14个月，平均6个月，均无PE发生。术前曾出现PE的5例滤器置入后未再发生PE。结论下腔静脉滤网置入是一种简便、安全措施，可有效预防深静脉血栓形成后PE的发生。     

临时滤器捕捉血栓预防肺栓塞的临床观察

目的　观察下肢深静脉血栓形成患者置入的腔静脉临时滤器后捕捉血栓和预防肺栓塞的效果。方法　对确诊单侧下肢深静脉血栓形成的 5 8例患者 ,治疗前经健侧肢体置入腔静脉临时滤器 (antheortemporaryfilter,ATF)并实施手术腔内治疗和 或抗凝溶栓治疗 ,临床观察有无出现肺栓塞症状和体征。治疗后拨除临时滤器观察血栓的捕捉。结果　下腔静脉滤器置入全部成功 ,下肢深静脉血栓形成患者治疗后效果良好 ,无症状性肺栓塞发生。置入滤器平均 (1 2 . 0± 2 . 0 )d取出。临时滤器捕捉血栓患者 4 6例 ,占 79. 3%,其中 2例捕捉到大于 1cm血栓 ,经切开股静脉将滤器和血栓一并取出。结论　临时滤器预防肺栓塞安全有效 ,无远期并发症之忧 ,下肢深静脉血栓形成患者为预防肺栓塞措施置入临时滤器是有必要的。     

超声引导下腔静脉滤器置入术的临床应用

目的探讨彩色多普勒超声引导下下腔静脉滤器置入术的临床应用价值。方法对我院收治的16例单侧下肢深静脉血栓（DVT）患者,在彩色多普勒超声经腹扫查实时动态引导下,行经健侧股静脉下腔静脉滤器置入术。结果 16例患者均在实时彩色多普勒超声引导下,置入VenaTechTMLP永久型下腔静脉滤器16只。术中出血少,无肺栓塞发生及滤器误置入其他血管。术后伤口均恢复良好,术后1周至半年超声及X线随访示滤器无变形、移位,无肺栓塞发生。结论超声引导下经皮穿刺下腔静脉滤器置入术是一种安全、可靠、简便、经济、无辐射的方法 ,具有较高的临床应用价值。     

下腔静脉滤器置入术预防肺栓塞的临床观察

目的：探讨下腔静脉滤器置入术对下肢深静脉血栓形成后引起肺栓塞的预防效果。方法：14例下肢静脉血栓形成患者采用Seldinger技术施行下腔静脉滤器置入术。结果：滤器全部安全置入肾静脉下方的下腔静脉内。随访1月～40月，10例无肺栓塞的患者，无肺栓塞发生，滤器无移位，4例已有肺栓塞者无加重。结论：下腔静脉滤器用于预防肺动脉栓塞是一种安全有效的方法。     

下腔静脉滤器在治疗下肢深静脉血栓中的应用

目的探讨下腔静脉滤器在治疗下肢深静脉血栓中的应用价值。方法46例下肢深静脉血栓患者在其他治疗前先置入下腔静脉滤器,然后其中20例采用抗凝、溶栓等药物治疗＋气压梯度治疗,另26例实施手术治疗,并同时采取抗凝、溶栓及气压梯度治疗。观察本组患者有无出现肺栓塞的症状及体症,定期透视滤器的形态与位置。结果下腔静脉滤器置入全部成功,其中置入永久性下腔静脉滤器38例,置入临时性下腔静脉滤器8例。经治疗46例患者中44例的下肢深静脉血栓症状及体征消失或缓解,无肺栓塞发生。对置入永久性下腔静脉滤器者中的36例进行2～24个月的随访（平均13个月）,滤器无移位,未发生肺栓塞。结论下腔静脉滤器置入方法简单、安全,可有效防止肺动脉栓塞的发生,可为下肢深静脉血栓治疗提供有效保障。     

永久性下腔静脉滤器置入后相关并发症探讨

目的　探讨永久性下腔静脉滤器置入术后 ,相关并发症出现的原因和预防措施。　方法　 1999年 12月～ 2 0 0 3年 6月 ,71例经彩色超声确诊下肢深静脉血栓 (deepveinthrombosis,DVT)置入永久性下腔静脉滤器 (venacavafilter ,VCF) ,其中急性下肢DVT 4 0例。术中常规行下腔静脉造影 ,确定下腔静脉和滤器释放途径静脉无血栓形成 ,将滤器放置平于肾静脉开口之下的下腔静脉。应用的滤器包括Titan -Greenfield滤器、Simon -Nitinol滤器、LGM滤器和TrapEase滤器。术后常规肝素和华法令抗凝。　结果　本组VCF均释放成功。术后 1～ 4 1个月随访 ,下腔静脉滤器放置部位血栓形成 2例 ,滤器倾斜 5例 ,倾斜角度 <15°。无滤器释放不全、穿孔、脱落、移位、出血和滤器释放通路血栓形成 ,无肺栓塞 (pulmonaryembolism ,PE)发生。　结论　不同类型滤器出现并发症的种类和发生率不同。滤器置入术前行彩色超声检查和术中下腔静脉造影 ,了解下腔静脉和VCF放置通路的情况 ,术中操作要点的实施 ,以及术后严格的抗凝治疗 ,是确保VCF放置成功、有效预防PE发生、避免或降低并发症的关键。     

下腔静脉滤器在下肢深静脉血栓治疗中的应用

目的 探讨下肢深静脉血栓形成患者置人下腔静脉滤器预防肺栓塞的作用。方法 55例下肢深静脉血栓患者治疗前置人下腔静脉滤器，其中Simon Nitiol滤器(SNF)25例，Trap Ease滤器(TEF)13例，Antheor Temporal滤器(ATF)17例。10例采用抗凝溶栓治疗，45例实施手术和腔内治疗，临床观察有无出现肺栓塞症状和体症，定期透视SNF和TEF的形态与位置。结果 下腔静脉滤器置人全部成功，经治疗下肢深静脉血栓症状及体征消失．无肺栓塞发生。1例置入SNFl6个月，出现下腔静脉阻塞；17例临时性置放滤器者ATF取出后发现有血栓性物质。结论 腔静脉滤器近期预防肺动脉栓塞简便安全有效，远期并发症要引起重视，并待进一步研究。     

下腔静脉滤器置入预防肺栓塞57例报告

[目的]探讨下腔静脉滤器置入术预防致命性肺动脉栓塞的疗效和安全性.[方法]在数字减影动脉造影(DSA)下57例下肢深静脉血栓形成的患者成功进行下腔静脉置人术,术巾观察和术后随访了解预防肺栓塞的发生及相关并发症.[结果]所有病例随访3～24个月(平均13.1个月),无1例患者出现肺栓塞和相关并发症.[结论]下腔静脉滤器置入是预防肺动脉栓塞发生的安全、有效的方法.     

下腔静脉滤器预防肺栓塞及其并发症

目的探讨放置下腔静脉滤器在预防下肢深静脉血栓导致肺栓塞中的临床作用。方法74例下肢深静脉血栓形成患者(42例已经发生肺栓塞),为预防肺栓塞或再次肺栓塞而置入下腔静脉滤器,65例患者放置永久滤器,9例年轻患者放置可回收滤器。除8例有抗凝禁忌证患者外,其他患者行抗凝溶栓治疗。可回收滤器在放置后6~15天取出。随访观察有无滤器并发症、肺栓塞或复发肺栓塞出现。结果滤器均成功放置,患者未出现滤器错位、移位、倾斜、血栓脱落、滤器折断、腔静脉穿孔等并发症,随访期内未发现肺栓塞或复发肺栓塞,2例放置永久滤器的患者出现滤器血栓形成,1例放置可回收滤器的患者下腔静脉造影发现滤器血栓形成,其他8例可回收滤器取出后肉眼可见血栓,虽然造影没有发现。结论下腔静脉滤器作为预防肺栓塞的方法其效果值得肯定,但应该注意滤器血栓形成,在放置前选择合适的适应证。     

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.