钢丝环形加“8”字内固定治疗髌骨骨折

为对髌骨骨折钢丝环形加“８”字内固定进行生物力学评价，本实验采用截肢获得的６个髌骨标本进行研究。保留股四头肌腱和髌韧带。于髌骨纵向中点横形锯开，造成横形骨折。髌骨骨折四种内固定方法即：钢丝环形加“８”字、钢丝“８”字、钢丝环形和克氏针加钢丝“８”字内固定。使固定的髌骨韧带标本屈曲９０°，应用电测法对固定性能进行测试。载荷—应变评价结果表明，钢丝环形加“８”字固定效果最好。因此，从１９８８年３月～１９９１年７月应用此法治疗１２７例髌骨骨折，获得随访９６例，优、良结果占９５．８％。     

两种张力带钢丝内固定治疗髌骨骨折的临床观察

髌骨骨折是比较常见的骨折，占全身各部骨折的1．65％左右，治疗上有多种内固定方法。我院自1996年以来分别采用了克氏针张力带钢丝与钢丝环形加“8”字张力带钢丝内固定治疗髌骨骨折，术后进行0．5～2年的随访，并分别对其疗效进行了回顾性的分析、比较。钢丝环形加“8”字张力带     

髌骨骨折几种内固定方法的临床疗效比较

髌骨骨折手术治疗内固定方法很多,疗效不一,自1995～2004年采用环形加张力带"8"字钢丝(环-袢钢丝)法、改良AO张力带(AO)法、张力带"8"字钢丝(袢钢)法、环形钢丝(环钢)法、环形丝线(环线)法、镍钛-聚髌钉(NT钉)法六种方法治疗新鲜髌骨骨折153例,评价以上几种内固定方法对髌骨骨折的治疗效果.     

横“U”加“8”字形张力带钢丝内固定治疗髌骨骨折

目的探讨单纯横“U”形加“8”字张力带钢丝内固定治疗Ⅱ型及Ⅲa型髌骨骨折的特点。方法据髌骨骨折的移位情况和骨折块的大小、数量将髌骨骨折分为Ⅰ～Ⅲ型，回顾2003年1月至2008年2月采用单纯横“U”形加“8”字张力带钢丝内固定方法治疗的135例Ⅱ型及Ⅲa型髌骨骨折患者。结果经6个月～5年的随访，135例骨折全部愈合，无内固定松动、感染及创伤性关节炎等并发症发生。结论单纯横“U”形加“8”字张力带钢丝内固定疗效可靠，方法简单，是一种简便有效的治疗Ⅱ型及Ⅲa型髌骨骨折的方法。     

髌骨骨折4种内固定方法比较

目的：分析306例髌骨骨折疗效。方法：采用环形钢丝、克氏针钢丝张力带、改良AO张力带、环形钢丝加“8”字张力带带治疗306例髌骨骨折。结果：术后平均随访18个月（6－72个月）,优193例,良83例,可23例, 差7例。结论：环形钢丝法不应作为治疗常规和首选。对于髌骨横断形骨折,环形钢丝加“8”字张力带及AO张力带法可取得良好效果,对于粉碎性髌骨骨性,环形钢丝加8字张力带法是有效,可靠的手术方式。     

环形加"8"字钢丝内固定治疗髌骨骨折15例

我科自2002年1月～2004年3月,采用环形加“8”字钢丝内固定治疗髌骨骨折15例,取得了良好效果,报道如下.     

钢丝“8”字加“0＂形环扎治疗髌骨骨折

目的探讨钢丝“8”字加“0”形环扎治疗髌骨骨折的应用价值。方法对76例髌骨骨折,采用单纯钢丝“8”字加“0”形环扎治疗。结果74例获得满意复位,骨折及膝关节功能恢复良好。结论钢丝“8”字加“0”形环扎治疗髌骨骨折具有确实可行性,治疗确切且费用低、下地时间早、关节功能恢复快等优点,是一种值得推广的方法。     

矩形钢丝环加8字型张力带钢丝固定术治疗髌骨骨折

自1988年8月以来,我院根据张力带钢丝治疗髌骨骨折的原理,对其固定方法加以改进。由原来的纵形钻洞固定,改为横形钻洞固定;由原来的双克氏针加单钢丝张力带或单纯的“8”字张力带固定,改用矩形钢丝环加“8”字型张力带固定。共治疗髌骨骨折36例,效果良好,现报道如下。     

胸骨针钢丝环扎加髌前“8”字结扎治疗髌骨骨折

目的探讨胸骨针钢丝环扎加髌前“8”字结扎治疗髌骨骨折的临床效果。方法对58例髌骨骨折采用胸骨针钢丝环扎加髌前“8”字结扎治疗。结果随访11—18个月。优51例,良7例。结论胸骨针钢丝环扎加髌前“8”字结扎具有手术创伤小、时间短、操作方便等优点．可作为不同类型髌骨骨折的常规选择。     

尺骨鹰嘴骨折钢丝环形加"8"字内固定的实验研究及其临床应用

[目的]本课题通过比较尺骨鹰嘴骨折钢丝环形加“8”字与常用的4种内固定的稳定性,探讨尺骨鹰嘴骨折不同内固定的生物力学效应,旨在寻求尺骨鹰嘴骨折理想的内固定方式,为临床选择内固定提供实验依据,从而验证和指导临床治疗。[方法]采用20只成年男性肘关节新鲜尸体标本,建立横形、斜形、粉碎形三种不同模型尺骨鹰嘴骨折模型,分别采用钢丝环形、钢丝“8”字、钢丝环形加“8”字、克氏针张力带及螺丝钉5种不同方法进行内固定,使固定的肘关节标本屈曲90°,运用高精度位移传感器对固定性能进行测量。[结果]位移-载荷关系表明,单环形钢丝固定强度最小,钢丝环形加“8”字比单“8”字钢丝及螺丝钉强,统计学上差异显著(P<0.05);在横形、斜形骨折模型中,钢丝环形加“8”字组与克氏针张力带组相差不显著(P>0.05),但在粉碎性骨折模型中,钢丝环形加“8”字组与克氏针张力带组有显著性差异(P<0.05);临床应用26例中,全部愈合,平均随访12个月,优良率达92.30%。[结论]钢丝环形加“8”字内固定可用于治疗横、斜形及粉碎性尺骨鹰嘴骨折,对粉碎性骨折效果优佳,且创伤小、操作简便、固定牢靠,是一种安全可靠,值得临床推广应用的内固定方法。     

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 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.     

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.