AF内固定治疗胸腰段骨折近期疗效评价

目的 评价AF椎弓根螺钉内固定系统治疗胸腰段骨折的近期疗效。方法 我科自2004年7月至2005年7月间采用AF椎弓根螺钉内固定系统治疗胸腰段骨折32例。部分患者行椎管减压，横突间植骨融合。结果经术后9～13个月的随访，与术前比较，术后及末次随访时的Cobb’s角及椎体前、后缘高度均明显恢复（P〈0．01）。本组患者脊髓损伤分级评判，除1例完全性瘫痪患者术后无功能恢复外，其余患者均获得了不同程度的功能恢复。结论 AF椎弓根内固定系统治疗胸腰段骨折，固定牢靠，椎体高度再丢失少。间接复位能使突入椎管腔内的伤椎椎体后壁精确复位，使椎管有效减压。     

椎弓根钉内固定治疗胸腰椎骨折

目的：探讨脊柱胸腰段骨折椎弓根钉内固定治疗效果。方法：临床收治脊柱胸腰段骨折72例，均采用后路减压，Dick或RF系统钉内固定手术治疗。比较手术前后骨折复位及神经功能恢复情况。结果：术后椎体高度完全或基本恢复占95．8％，神经功能有Frankel一级以上改善，不完全截瘫占90％，完全截瘫占53．1％。随访3—38个月，无螺钉折断、后退及脊柱矫正度丢失。结论：开放复位后路椎弓根钉内固定是治疗胸腰椎骨折的有效方法。     

后路椎弓根螺钉固定及经椎弓根植骨治疗胸腰段脊柱爆裂性骨折

目的探讨后路椎弓根螺钉固定及经椎弓根植骨治疗胸腰段脊柱爆裂性骨折的治疗效果。方法采用后路椎弓根螺钉固定及经椎弓根植骨治疗24例胸腰段脊柱爆裂性骨折的患者。分析术前、术后神经功能恢复情况,伤椎椎体高度变化、Cobb’S角、椎管占位情况比及腰背部疼痛情况。结果所有手术均顺利完成,随访术后12～24个月,未发现断钉及内固定物松动,椎体高度和后凸角无明显再丢失,术前和术后Cobb’S角、椎体前缘高度、椎体平移率、VAS的比较差异有统计学意义（P〈0．05）。结论后路椎弓根螺钉固定及经椎弓根植骨治疗胸腰段脊柱爆裂性骨折操作简单、安全可靠,不增加软组织刨伤,并发症少,并且能获得更好的骨折复位以及避免后期椎体高度丢失。     

椎体成形术在胸腰段不稳定骨折中的应用

目的探讨碳酸化羟基磷灰石水泥(CHC)作为充填材料在椎体成形术治疗胸腰段不稳定椎体压缩骨折手术中的应用效果。方法22例胸腰段椎体不稳定压缩骨折患者采用椎弓根螺钉系统撑开复位和内固定,通过骨折椎体的椎弓根进行椎体成形术,在椎体内注入CHC增强椎体,观察其治疗效果。结果术后X线片显示,CHC固化后充填在椎体中前柱,与骨界面结合紧密,椎体的高度平均恢复到80%~100%(95%±3·6%)。随访24~36个月,均未出现椎弓根钉棒断裂和弯曲。结论胸腰段椎体不稳定压缩骨折采用椎弓根螺钉内固定同时行椎体成形术,椎体充填CHC可以有效恢复椎体前柱力学强度,降低椎弓根钉棒断裂的风险。     

经伤椎椎弓根植骨加椎弓根螺钉固定治疗胸腰段爆裂性骨折

目的观察经伤椎椎弓根植骨加椎弓根螺钉固定治疗胸腰段爆裂性骨折的效果。方法对40例胸腰段爆裂性骨折患者实施经伤椎椎弓根植骨加椎弓根螺钉固定治疗。观察治疗前、术后第3天及12个月后的腰背部疼痛改善效果、伤椎椎体高度变化和末次随访神经功能恢复情况。结果术后第3天患者腰部疼痛VSA疼痛评分、伤椎椎体高度、Cobb角等指标均优于术前,差异有统计学意义(P 0. 05)。随访12个月,其间未出现断钉和内固定物松动的现象。复查CT,椎体内植骨颗粒均获骨性愈合。椎体高度和后凸角未发现再丢失,腰背疼痛未复发。末次随访神经功能优于术前。结论经伤椎椎弓根植骨加椎弓根螺钉内固定治疗胸腰段爆裂性骨折,伤椎高度重建理想,维持伤椎的三柱稳定性高,疼痛缓解及神经功能恢复好,效果可靠。     

胸腰段骨折病理特点及治疗

目的探讨胸腰段骨折的病理特点及椎弓根螺钉内固定系统在其治疗中的应用及临床效果。方法 2005年3月～2010年3月,共94例胸腰段骨折患者行根螺钉内固定治疗,其中行跨伤椎椎弓根螺钉内固定术76例,行经伤椎椎弓根螺钉内固定术18例。通过观察伤椎椎体高度、伤椎后凸Cobb角、疼痛视觉模拟量表（visual analoguescale,VAS）评分、美国脊髓损伤学会（American Spinal Injury Association,ASIA）评分及术后X线片对患者的恢复情况进行评价。结果所有患者术后随访6～24个月,平均15个月。患者椎体高度恢复率为89%～100%,平均为94%;Cobb角恢复到0°～6°,平均2.3°;VAS评分恢复至0～3分,平均1.3分;神经功能明显恢复,与术前相比差异有统计学意义（P〈0.05）。结论椎弓根螺钉内固定系统是治疗胸腰段骨折的有效方法,其中短节段经伤椎椎弓根内固定可能成为一种更具优势的内固定方式。     

单节段伤椎椎弓根螺钉内固定治疗胸腰段骨折

目的：探讨单节段伤椎椎弓根螺钉内固定治疗胸腰段骨折的可行性。方法：回顾性分析2008年3月。2011年2月对于AO分型A3．1,A1．2的胸腰段骨折38例患者进行了单节段伤椎椎弓根螺钉复位内固定,并抽取了35例同时间段AO分型A3．1,A1．2的胸腰段骨折应用短节段复位内固定的患者从复位效果进行了对比研究,随访3～36月,平均23月。结果：单节段组与单节段组从年龄、骨折节段、术前后凸角和椎体前高的丢失、术后后凸角和椎体前高的丢失的纠正均无显著性差异。结论：单节段伤椎椎弓根螺钉内固定治疗胸腰段骨折是一个可行的方法,但是适应症较窄,并且对螺钉的置入和复位都有一定的技术要求。     

椎弓根钉治疗胸腰段骨折的临床疗效

目的 :评价椎弓根螺钉内固定系统治疗胸腰段骨折的临床效果。方法 :分析 76例应用椎弓根内固定系统(Dick、RF或AF ,治疗的胸腰段骨折患者术前、术后和随诊时的临床表现、X线片和CT。平均随访 16个月。结果 :76例患者伤椎椎体高度比和Cobb′s角分别是术前 0 .48,2 8.5 ,术后 0 .91,6.5 ,随诊 0 .71,14 .5。在随访时有不同程度的丧失。结论 :椎弓根内固定系统是治疗胸腰段骨折的有效方法 ,但后期仍存在一些问题。     

AF椎弓根内固定系统治疗不稳定性胸腰段骨折合并截瘫

目的 评价AF推弓根螺钉内固定系统治疗不稳定性胸腰段骨折合并截瘫的疗效。方法 1997年5月至2001年5月,采用AF椎弓根螺钉内固定结合推移复位法治疗不稳定性胸腰段骨折合并截瘫38例。结果 Cobb’s角由术前平均23.8°(11°～43°)矫正到术后平均2.6°(0°～8°)。椎体前、后缘高度由术前46％(23％～68％)和70％(32％～80％)恢复到术后的92％(89％～100％)与97％(94％～100％)。三者均有显著统计学差异(P<0.01)。术后随访6～28个月,平均随访10.5个月,32例不完全性截瘫患者均有1～3级恢复,6例全瘫患者中,4例有1～2级恢复。结论 AF椎弓根内固定系统能使突入椎管腔内的伤椎椎体后壁精确复位,牢靠固定,并使椎管有效减压。在某些前、后纵韧带完整性已遭破坏的爆裂型骨折、脱位病例,推移复位法可作为AF内固定系统的必要补充。     

后路单节段椎弓根螺钉内固定选择性治疗胸腰椎骨折

目的：探讨后路单节段椎弓根螺钉内固定选择性治疗胸腰椎骨折的临床疗效。方法：自2005年6月至2008年6月,行后路单节段椎弓根螺钉内固定治疗胸腰椎骨折28例,男17例,女11例;年龄19-60岁,平均36岁。骨折根据AO分型：A1型19例,A2型9例。观察骨折椎的椎弓根螺钉位置及手术前后骨折椎的复位情况。结果：术后CT示骨折椎56枚椎弓根螺钉均在正常骨性结构内,均未通过骨折线。术后无脊髓损伤、感染等并发症发生。骨折椎体前缘压缩率从术前平均（42．0±5．6）％恢复至（12．4±1.4）％（P〈0．05）;骨折椎后凸Cobb角从术前平均（25．8±5．1）°废复至（1．9±1．3）°（P〈0．05）。28例患者术后均获随访,平均18.3个月（3-36个月）,骨折全部获得骨性愈合,骨折椎体高度无明显丢失,无钉棒弯曲、松动或断裂。结论：只要手术适应证选择正确,后路单节段椎弓根螺钉内固定可用于治疗胸腰椎骨折。     

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.     

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.