肌腱结嵌压双股腘绳肌腱重建前交叉韧带的动物实验模型:体外生物力学性能测定

目的 :建立肌腱结嵌压双股腘绳肌腱重建前交叉韧带 (ACL)的动物实验模型 ,对重建早期的生物力学性能进行测定和评价。方法 :在猪膝关节的股骨端 ,用自行设计的联合阶梯状钻头在与股骨干纵轴成 45°角向股骨髁间窝 1 1点处钻一瓶颈状骨性隧道。腘绳肌腱中间打结后并成双股穿过骨性隧道 ,肌腱结在隧道的阶梯处形成嵌压。测定肌腱结在骨性隧道内可承受的最大载荷和负载时的位移量。对照组用骨-髌腱-骨 (B PT B)进行ACL重建。结果 :肌腱结嵌压组可承受的最大载荷为 ( 680± 1 3 0 )N ,>B PT B组的 ( 4 59± 1 47)N (P <0 .0 1 )。在 40 0N的生理载荷下 ,肌腱结嵌压重建ACL产生的位移量为 ( 9.85± 2 .96)mm ,B PT B组为 ( 7.49± 2 .67)mm ,两组之间没有明显差异 (P >0 .0 5)。结论 :肌腱结在骨性隧道内的嵌压具有良好的生物力学性能 ,可以满足前交叉韧带重建的生物力学需要。     

肌腱结嵌压固定法重建前交叉韧带生物力学实验研究

目的探讨绳肌腱结嵌压固定法重建前交叉韧带(ACL)影响初始固定效果的相关因素及对策。方法采用猪膝关节模拟重建ACL不同术式,即绳肌腱结股骨隧道嵌压固定和胫骨端肌腱编织缝合骨桥打结固定法,与骨-髌腱-骨两端界面螺钉固定法,比较其生物力学初始固定最大拔出载荷、抗拉刚度和位移等生物力学指标。结果最大抗拉载荷肌腱结组与正常ACL组接近,无显著性差异;肌腱结组大于骨-髌腱-骨界面螺钉固定组。抗拉载荷在100N和400N时的位移两组无显著性差异。胫骨端肌腱编织缝合骨桥上打结固定组最大抗拉载荷大于BPTB界面螺钉固定组和肌腱编织缝合后界面螺钉固定组。抗拉刚度正常ACL组>骨-髌腱-骨组>绳肌腱结组。最大位移正常ACL<髌腱骨组<肌腱结组。结论绳肌腱结嵌压固定法抗拉强度和刚度完全可以满足重建后ACL的生理需求;术中克服位移因素,是有效防止ACL重建术后松弛的关键。     

嵌压固定法重建前交叉韧带不同肌腱移植物的选择

[目的]探讨嵌压固定法重建前交叉韧带(ACL)不同肌腱移植物的选择。[方法]采用嵌压固定法重建前交叉韧带101例,男68例,女33例。运动伤62例,交通伤22例,生活伤17例。采用绳肌腱结42例、骨栓绳肌腱结32例、带髌骨块的股四头肌腱27例。选用自体半腱肌腱和股薄肌腱,两端编织缝合预张力后在双股肌腱中间打结。将绳肌腱结内嵌入5 mm×11 mm的矩形骨栓,制成直径11 mm的骨栓肌腱结;带髌骨块的股四头肌腱全长70~80 mm,骨块11 mm×9 mm×7 mm。采用阶梯状联合钻建立股骨隧道,根据患者个体情况不同,选用自体绳肌腱结、骨栓绳肌腱结或带髌骨块的股四头肌腱,进行嵌压固定法重建ACL。将肌腱结或带髌骨块的股四头肌腱完全嵌入到瓶颈状股骨隧道内,在胫骨隧道外口分两股穿出,交叉打结固定在胫骨桥上。[结果]98例患者得到随访,膝关节稳定,功能恢复良好。按照膝关节疗效评定标准,优88例,良6例,可4例,优良率85.7%。[结论]根据患者个体情况选择绳肌腱结、骨栓肌腱结或带髌骨块的股四头肌腱,进行嵌压固定法重建ACL,生物固定、方法简便、固定可靠、创伤小、费用低。     

国人腘绳肌腱移植不同固定方式重建ACL的生物力学研究

[目的]探讨腘绳肌腱移植重建ACL股骨与胫骨侧采用不同固定方式的生物力学特性。[方法]采用新鲜冷冻尸体膝关节标本,腘绳肌腱移植,股骨侧分别用Endobutton(n=8)、Rigidfix(n=8)、肌腱结(n=8)和界面螺钉固定(n=8)。胫骨端采用可吸收界面螺钉(n=7)和Intrafix(n=7)固定,模拟ACL重建。进行循环载后位移、抗拉刚度、失效载荷、最大载荷等生物力学。[结果]失效载荷和最大载荷:EndobuttonRigidfix肌腱结界面螺钉固定法,差异有统计学意义(P0.01),Rigidfix和界面螺钉之间的差异有统计学意义(P0.05)。抗拉刚度:Rigidfix=肌腱结界面螺钉固定Endobutton。循环载荷位移:肌腱结固定组Rigidfix固定组Endobutton固定组界面螺钉固定组。胫骨端最大载荷:Intrafix固定组可吸收界面螺钉组,两者之间差异有统计学意义(P0.05);100 N、400 N抗拉刚度两组间差异无统计学意义(P0.05)。[结论]采用Endobutton、Rigidfix、intrafix、肌腱结和界面螺钉ACL重建固定均可满足力学需求;Rigidfix和Intrafix固定系统较界面螺钉固定更具有生物力学优势。     

腘绳肌腱结嵌压固定法重建交叉韧带的临床应用与生物力学研究

目的探讨腘绳肌腱结嵌压固定法重建交叉韧带的可行性。方法对52例陈旧性前、后交叉韧带损伤患者在关节镜下行双股腘绳肌腱中间打结,嵌入瓶颈状股骨隧道内固定,胫骨端采用肌腱编织缝合在骨桥上打结固定,重建交叉韧带。其中前交叉韧带25例,前、后十字韧带同时重建15例,后交叉韧带12例。生物力学实验采用猪膝关节。股骨端固定分为肌腱结嵌入组(n=13)和骨髌腱骨(B PT B)介面螺钉固定组(B PT B介面钉组,n=11)。胫骨端固定分为肌腱编织缝合线在骨桥打结组(n=7)、肌腱编织缝合介面螺钉组(n=8)。进行最大拔出强度、最大位移和固定刚度等力学实验。结果术后随访49例,平均14 6个月,Lanchman试验阴性46例,阳性3例。术后Lysholm评分由术前56 7分提高到92 8分。按膝关节疗效评定标准,优46例,良3例。生物力学实验最大拔出强度肌腱结嵌入组高于B PT B介面钉组;固定刚度肌腱结嵌入组小于B PT B介面钉组;最大位移肌腱结嵌入组大于B PT B介面钉组。胫骨端固定抗拉强度和刚度骨桥打结组优于介面螺钉组。结论腘绳肌腱结嵌压固定重建交叉韧带生物力学抗拉强度能满足生理需求,方法可行;可克服位移因素,降低韧带松弛率,提高疗效。     

Guo绳肌腱结嵌压固定法重建交叉韧带的临床应用与生物力学研究

目的探讨Guo绳肌腱结嵌压固定法重建交叉韧带的可行性。方法对52例陈旧性前、后交叉韧带损伤患者在关节镜下行双股Guo绳肌腱中间打结，嵌入瓶颈状股骨隧道内固定，胫骨端采用肌腱编织缝合在骨桥上打结固定，重建交叉韧带。其中前交叉韧带25例，前、后十字韧带同时重建15例，后交叉韧带12例。生物力学实验采用猪膝关节。股骨端固定分为肌腱结嵌入组(n=13)和骨-髌腱-骨(B-PT-B)介面螺钉固定组(B-PT-B介面钉组，n=11)。胫骨端固定分为肌腱编织缝合线在骨桥打结组(n=7)、肌腱编织缝合介面螺钉组(n=8)。进行最大拔出强度、最大位移和固定刚度等力学实验。结果术后随访49例，平均14．6个月，Lanchman试验阴性46例，阳性3例。术后Lysholm评分由术前56．7分提高到92．8分。按膝关节疗效评定标准，优46例，良3例。生物力学实验最大拔出强度：肌腱结嵌入组高于B-PT-B介面钉组；固定刚度肌腱结嵌入组小于B-PT-B介面钉组；最大位移肌腱结嵌入组大于B-PT-B介面钉组。胫骨端固定抗拉强度和刚度骨桥打结组优于介面螺钉组。结论Guo绳肌腱结嵌压固定重建交叉韧带生物力学抗拉强度能满足生理需求，方法可行；可克服位移因素，降低韧带松弛率，提高疗效。     

关节镜下自体腘绳肌腱重建前交叉韧带的康复与护理

[目的]对关节镜下胭绳肌腱结嵌压固定重建前交叉韧带（ACL）的康复与护理进行探讨。[方法]对14例ACL损伤行关节镜下胭绳肌腱结嵌压固定重建ACL的患者，分为4个阶段进行指导：术前指导、术后护理、术后功能锻炼、出院指导。[结果]14例患者得到随访，关节稳定，功能恢复正常。采用Lysholm膝关节功能评分，术前平均63．5分，终末随访平均94．5分，术后提高31．0分。[结论]阶段指导可操作性和针对性强，规范的康复护理为术后膝关节功能恢复提供了强有力的保证，有效促进关节镜TIN绳肌腱结嵌压固定重建ACL的功能康复。     

膨胀螺钉固定重建前交叉韧带的生物力学研究

背景:关节镜下重建前交叉韧带(ACL)的方法很多,且疗效较好。但目前尚无有关固定方法是否能提供坚强固定、恢复原有ACL生物力学特性的相关研究。目的:探讨股骨端膨胀界面螺钉固定腘绳肌腱移植重建ACL的生物力学。方法:取新鲜冰冻成人膝关节标本21具,采用4股腘绳肌腱移植重建ACL,股骨端分别使用膨胀界面螺钉(n=7)、可吸收界面螺钉(n=7)、金属界面螺钉(n=7)固定,测试循环载荷后位移、100 N位移、400 N位移、抗拉刚度、最大拔出载荷、失败模式以及肌腱切割程度等,并进行统计学分析。结果:循环载荷后位移:可吸收螺钉组<金属螺钉组<膨胀螺钉组,无统计学差异(P>0.05);最大拔出载荷:膨胀螺钉组>可吸收螺钉组>金属螺钉组,膨胀螺钉组与可吸收螺钉组比较无统计学差异(P>0.05),膨胀螺钉组与金属螺钉组比较有统计学差异(P<0.05);肌腱切割程度:膨胀螺钉切割伤最轻,可吸收螺钉次之,金属螺钉最重。结论:膨胀界面螺钉的最大拔出载荷、100 N位移、400 N位移以及抗拉刚度均超过普通界面螺钉,对移植肌腱损伤小,可以满足肌腱重建固定ACL的需要,并可实现单隧道ACL双束解剖重建。     

肌腱结嵌压固定保留胫骨止点的胭绳肌腱重建前交叉韧带

目的：探讨以自体骨栓肌腱结嵌压固定保留胫骨止点的胭绳肌腱重建膝前交叉韧带的临床效果及应用价值。方法：采用自体骨栓肌腱结嵌压固定保留胫骨止点的胭绳肌腱重建膝前交叉韧带断裂20例，男15例，女5例；年龄18～32岁，平均22岁；左、右膝各10例。取自体胭绳肌腱，保留肌腱的胫骨止点，两端编织缝合后预张。建立胫骨、股骨隧道，并制作胫骨骨桥结构，股骨隧道为内窄外宽结构。骨栓肌腱结嵌入股骨隧道内，牵引线带着肌腱结远端的腱束经股骨、胫骨隧道穿出，与胫骨止点上的肌腱交叉，在胫骨骨桥上打结并缝合固定。术后患膝以支具固定在屈曲45。位。结果：20例患者均获得随访，随访时间8—24个月，平均11个月。膝关节功能评估采用Lysholm功能评分标准，术前平均（61．5&#177;4．6）分，终末随访时平均（92．5&#177;3．7）分，差异有统计学意义，P〈0．05。结论：骨栓肌腱结嵌压固定保留胫骨止点的胭绳肌腱重建膝前交叉韧带的方法为生物学固定，避免使用高值耗材，降低了手术费用，且有利于腱-骨愈合。     

关节镜下骨栓胭绳肌腱结嵌入固定法重建膝前后十字韧带

目的探讨关节镜下以自体骨栓腘绳肌腱结嵌入固定法联合重建膝前、后十字韧带损伤的应用价值.方法 2000年2月-2003年6月,采用自体骨栓腘绳肌腱结嵌入固定法同期联合重建前、后十字韧带损伤15例,男10例,女5例;年龄19-31岁,平均23岁;左9例,右6例.取自体胭绳肌腱,断端编织缝合并预张力后,在双股肌腱的中间打结嵌入骨栓并缝合固定.股骨隧道采用阶梯联合钻一次成形,呈倒置的瓶颈状.然后定位并建立前、后十字韧带的胫骨隧道.将"T"形的骨栓肌腱结嵌入瓶颈状股骨隧道内,两组肌腱缝线经胫骨隧道穿出,反复屈伸膝关节20次,在胫骨骨桥上交叉打结并缝合固定.术后患膝以支具固定在屈曲0°-30°位.结果 15例患者均获得随访,随访时间5～26个月,平均9个月.膝关节功能评估采用Lysholm功能评分标准,术前平均(61.5±4.6)分,终末随访时平均(92.5±3.7)分,差异有显著性(P＜0.05).膝关节稳定,功能明显改善.结论骨栓胭绳肌腱结嵌入固定联合重建前、后十字韧带的方法为生物固定,避免使用高值耗材和分次手术,降低手术费用,利于术后功能康复.     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.     

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.