C2,3椎弓根固定治疗不稳定性Hangman骨折

目的 探讨C23椎弓根固定术治疗不稳定性Hangman骨折的疗效.方法 2001年10月至2005年10月,治疗不稳定性Hangman骨折患者26例,男18例,女8例;年龄21～56岁,平均38.5岁.根据Levine等分型标准Ⅱ型11例,ⅡA型10例,Ⅲ型5例.脊髓功能Frankel分级,D级6例,E级20例.采用后侧入路,在"C"型臂X线机监视下复位骨折后,采用Axis或Vertex系统经C2,3椎弓根螺钉固定,行椎板间和关节突间植骨融合.以C2侧块中点为进针点,进针方向为向头端倾斜15°～25°,向中线倾斜20°～25°;螺钉长度为26～30 mm,直径为3.5～4.0 mm.以C3侧块的外上象限中点为进针点,水平面上进针方向为向头端内侧倾斜35°～45°,矢状面上丝锥在C3向头侧倾斜约10°,进深为20～25mm,长度为18～24 mm,直径为3.5～4.0 mm.结果 术后骨折复位满意,且全部愈合,颈椎功能无明显受限,无一例发生脊髓及椎动脉损伤.6例术前有神经症状者术后1周均有不同程度恢复.随访6～54个月,平均29个月.6例术前脊髓功能Frankel分级为D级的患者术后恢复至E级.术后CT检查示C2椎弓根螺钉偏外3枚(3/52);C3椎弓根螺钉偏外进入横突孔7枚(7/52);未发现螺钉偏内病例.按Mayo(McGrory)颈椎创伤后临床评价标准评分,优16例,良7例,可3例,优良率88.46%.结论 经C2,3椎弓根固定治疗不稳定性Hangman骨折可获得满意疗效.     

枢椎椎弓根拉力螺钉内固定技术治疗Hangman骨折

目的：探讨枢椎椎弓根拉力螺钉内固定治疗Hangman骨折的适应证,并评价其临床应用价值。方法：2003年7月至2007年6月共收治Hangman骨折患者28例。Levine-Edwards分型：Ⅰ型6例,Ⅱ型17例,Ⅱa型5例。脊髓功能Frankel分级：D级3例,E级7例。取C2侧块中点为进针点,根据C2椎弓根的内缘和上缘走行确定进针方向,向头侧倾斜25°～30°,向中线倾斜30°～35°。应用测深器确定螺钉长度,一般为24～30mm。结果：术中未发生椎动脉损伤及其他并发症。术后所有患者随访4～48个月,平均20个月。神经功能恢复正常,所有骨折均在术后6个月愈合,颈椎活动范围接近正常,未出现颈椎不稳和螺钉松动。结论：单节段枢椎椎弓根拉力螺钉内固定技术可使Hangman骨折获得良好的即刻稳定性,且较少干扰上颈椎的生理功能。其适应证应限于骨折可复位的病例。     

椎弓根及侧块螺钉内固定治疗不稳定性Hangman骨折

目的通过手术与非手术治疗比较,探讨椎弓根及侧块螺钉内固定治疗不稳定性Hangman骨折的技术操作要领和临床疗效。方法从1999年1月～2005年7月共收治36例不稳定性Hangman骨折,根据Levine-Edwards分型:15例颅骨牵引,21例实施后路椎弓根及侧块螺钉内固定术(C2,3融合10例,C2-4颈融合11例)。暴露C2,3或C2-4后方结构,取C2侧块中点为进钉点,一般为向头端倾斜20°～30°,向内倾斜25°～35°。对于C3、C4采用外倾斜35°～40°,与椎体关节面平行。所有操作均在C型臂X线机透视下完成。结果术后所有患者随访5～28个月,平均18个月。15例颅骨牵引者6例丢失复位位置,21例椎弓根螺钉内固定术者2例内固定松动,余均获骨性愈合,无颈椎功能受限。结论经C2,3、C2-4后路椎弓根及侧块螺钉内固定术是治疗不稳定性Hangman骨折的一种有效方法,达到复位固定和早期康复的目的,但两术式无明显差别。     

椎弓根螺钉固定或联合侧块螺钉固定治疗Hangman骨折

目的：探讨C2椎弓根拉力螺钉或C2椎弓根螺钉联合C3侧块螺钉固定治疗Hangman骨折的适应证,并评价其临床应用价值。方法：2001年3月至2005年8月共收治Hangman骨折患者44例,Levine-EdwardsⅠ型12例,Ⅱ型15例,Ⅱa型11例,Ⅲ型6例。脊髓功能Frankel分级：C级4例,D级16例,E级24例。Ⅰ型Hangman骨折采用C2椎弓根拉力螺钉固定;Ⅱ型、Ⅱa型、Ⅲ型采用C2椎弓根螺钉联合C3侧块螺钉固定。结果：术中未发生椎动脉损伤及其他并发症。术后4例Frankel C级患者2例恢复至E级,2例恢复至D级;16例D级患者14例恢复至E级,2例神经症状无变化。3～6个月时复查X线片示骨折均愈合。结论：C2椎弓根拉力螺钉或C2椎弓根螺钉联合C3侧块螺钉治疗Hangman骨折可以取得良好疗效。     

C2椎弓根螺钉联合C3侧块螺钉固定治疗不稳定性Hangman骨折

目的探讨C2椎弓根螺钉联合C3侧块螺钉内固定治疗不稳定性Hangman骨折的临床效果及应用价值。方法 2005年8月至2010年12月采用后路C2椎弓根螺钉联合C3侧块螺钉内固定治疗16例不稳定性Hangman骨折患者,男11例,女5例;年龄19～59岁,平均35.4岁。骨折按Levine-Edwards分类,型9例,a型5例,型2例。脊髓损伤按Frankel分级,D级3例,E级13例。结果所有患者均获随访,随访时间9～36个月（平均18个月）。手术时间95～170 min（平均114 min）,术中出血290～450 mL（平均353 mL）,术后6个月复查时,骨折均愈合,无断钉、断棒及螺钉松动发生,颈部活动功能恢复良好。脊髓功能D级3例均恢复至E级。结论经后路C2椎弓根螺钉联合C3侧块螺钉内固定是治疗Hangman骨折的良好手术方式。     

后路短节段钉棒内固定系统治疗Hangman骨折

目的 探讨后路C2～3短节段植骨融合内固定术治疗Hangman骨折的临床疗效.方法 对22例Hangman骨折患者采用后路C2椎弓根螺钉、C3侧块螺钉短节段植骨融合内固定术治疗.结果 22例均获随访,时间12～36个月.2例术前脊髓功能Frankel分级为D级者术后均恢复至E级.X线提示患者均达到骨性愈合,复位良好.无椎动脉和脊髓损伤发生.结论 后路C2椎弓根螺钉、C3侧块螺钉短节段植骨融合内固定技术治疗Hangman骨折疗效确切.     

C2椎弓根拉力螺钉选择性治疗Hangman骨折

目的探讨C_2椎弓根拉力螺钉治疗Hangman骨折的适应证,并评估其疗效。方法1998年2月～2000年12月共收治Hangman骨折患者22例。经颅骨牵引有10例骨折获得解剖复位但不稳定,对其中椎体结构完整的8例进一步施行了3.5mmC2椎弓根拉力螺钉内固定。男6例,女2例;年龄18～42岁,平均28.2岁。Levine-EdwardsⅠ型5例,Ⅱ型2例,Ⅱa型1例。脊髓功能FrankelD级2例,E级6例。患者全麻后俯卧于预制好的头-颈-胸石膏床腹片上,取后正中切口,暴露C1～C3后方结构。取C2侧块中点为进钉点,根据C2椎弓根的内缘和上缘走行确定进钉方向,一般为向头端倾斜25°～30°,向中线倾斜30°～35°。应用测深器确定螺钉长度,一般为25～30mm。所有操作均在“C”型臂X线机透视下完成。结果手术平均时间70min。未发现术后的早期和晚期并发症,神经功能恢复正常,所有骨折均在术后3个月愈合,颈椎活动范围接近正常,未出现C2,3的脱位和拉力螺钉的松动。结论C2椎弓根拉力螺钉技术可使Hangman骨折获得良好的即刻复位,通过骨块间加压恢复C2,3节段的稳定性。其适应证应限于骨折可复位的病例。     

C2椎弓根钉结合 C3侧块螺钉内固定治疗不稳定 Hangman 骨折简

目的探讨颈椎后路C2椎弓根钉结合C3侧块螺钉内固定治疗不稳定Hangman骨折的临床效果。方法对不稳定Hangman骨折28例入院后均颅骨牵引,行C2椎弓根钉结合C3,侧块螺钉内固定术。结果经24—42个月随访．术后神经功能恢复按Frankel分级,8例D级恢复至E级,20例E级未变化;6个月后骨折均愈合,复位良好,无椎动脉损伤等并发症。结论C2椎弓根钉结合C3侧块螺钉内固定术治疗不稳定Hangman骨折可获得满意疗效。     

椎弓根拉力螺钉内固定治疗Hangman骨折

探讨应用椎弓根拉力螺钉技术治疗Hangman骨折的临床疗效.方法 对12例Hangman骨折患者经颅骨牵引获得复位后,行C2椎弓根拉力螺钉内固定术治疗.术后行X线片检查观察骨折复位及愈合情况.结果 手术时间50～90min,失血量100～300ml.术中无脊髓神经损伤,骨折复位满意.12例均获随访,时间3~36个月.骨折完全愈合,无迟发畸形.2例脊髓神经损伤者术前Franke1分级为D级,术后3~6个月均恢复至E级.结论 C2椎弓根拉力螺钉技术治疗Hangman骨折,复位满意,固定可靠,疗效满意.     

不稳定Hangman骨折的手术治疗

目的 探泔颈椎后路椎弓根螺钉内同定治疗不稳定Hangman骨折的临床效果.方法 2001年10月至2006年4月收治15例不稳定Hangman骨折患者,骨折按照Levine-Edwards分型:Ⅱ犁3例,ⅡA型4例,Ⅲ型8例.入院后均给予颅骨牵引,行颈后路切开复位、椎弓根螺钉内固定术治疗.在复位不完全时,脱位不严重者采用C2.3复位固定;脱位严重时,在C<.2>椎弓根钉和C3侧块螺钉固定的基础上,增加C4的侧块螺钉固定.结果 术后随访3～30个月,平均17个月.6例术前脊髓功能Frankel分级为D级的患者术后恢复至E级,所有患者术后复奋X线片示:骨折全部获得骨件愈合,无明显的颈椎功能受限.结论 C2.3或C2-4后路椎弓根螺钉内固定手术是治疗不稳定Hangman骨折的有效方法,可达到早期复位、坚强同定的目的 .     

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.