胸腰段特发性脊柱侧凸的前路矫正术

目的评价胸腰段/腰段特发性脊柱侧凸经前路矫正术的临床效果。方法1998年1月~2004年1月,76例胸腰段/腰段特发性脊柱侧凸患者接受前路选择性矫正融合术。患者共76例,男19例,女57例,平均年龄为16.2岁(13~27岁)。按照Lenke分型,Ⅴ型41例,Ⅵ型35例。其中Lenke Ⅴ型术前胸腰段侧凸Cobb角平均51.3°(38°~65°),胸段侧凸Cobb角平均35.5°(23°~41°);Lenke Ⅵ型术前胸腰段侧凸Cobb角平均53.4°(46°~68°),胸段侧凸Cobb角平均39.2°(27°~51°)。所有患者均接受侧前路矫正选择性胸腰段融合。术后以及随访中对胸腰段侧凸矫正以及胸段代偿矫正情况进行分析对比,同时采用SRS-22评分评价患者手术前后的功能状况。结果患者均安全完成手术,无严重并发症发生。所有患者均随访2年以上(2~5年)。Lenke Ⅴ型组术后胸腰段侧凸Cobb角平均11.2°(3°~15°),胸段侧凸Cobb角平均8.3°(2°~11°),最终随访时分别为13.2°(5°~17°)和10.1°(4°~15°),无躯干冠状面失代偿发生;LenkeⅥ型组术后Cobb角平均16.3°(8°~21°),胸段侧凸Cobb角平均13.7°(11°~19°),最终随访时分别为17.5°(11°~24°)和15.2°(14°~21°);仅1例发生躯干冠状面失代偿,但不需要进一步治疗。两组之间无统计学差异。所有患者均在术后以及最终随访时填写了SRS-22评分表,结果显示两组患者均对治疗结果表示满意。结论胸腰段/腰段特发性脊柱侧凸经前路矫正、选择性融合可以获得良好矫正,术后胸段弯曲能够获得较好的代偿矫正,并在远期随访中维持矫正效果和躯干冠状面的平衡。     

前路Moss Miami器械矫形治疗特发性胸腰段或腰段脊柱侧凸

目的:评价MossMiami前路矫形系统对特发性胸腰段或腰段脊柱侧凸的手术效果。方法:对21例胸腰段或腰段特发性脊柱侧凸患者经前路胸腹联合入路行MossMiami矫形内固定,自体肋骨椎间植骨融合术。测量手术前后Cobb角以及躯干侧方位移。结果:Cobb角术前平均53°,术后平均5°,矫正率为90%。上方代偿性胸椎侧凸术前平均17°,术后矫正至平均5°。下方代偿性腰骶椎侧凸术前平均43°,术后自发矫正至19°。随访12~24个月,Cobb角平均丢失19.7°,胸腰段(T11~L1)术前平均前凸0.3°(0~4°),术后平均后凸3°(0~5°)。躯干侧方位移从术前平均26mm矫正至术后5mm。1例术后出现一侧下肢交感神经切断症状,2例术后并发气胸。无感染、截瘫及内固定失败等并发症发生。结论:MossMiami前路器械具有操作简单和低切迹的优点。棒的预弯、去旋转矫形、正确选择螺钉置入部位和椎间植骨可防止固定节段后凸畸形的形成。对Risser征小于4度的患者应密切观察上方代偿性胸椎侧凸进展情况。     

前路半椎体切除截骨后路矫形固定治疗严重先天性脊柱侧凸

目的探讨分期前路半椎体切除截骨后路矫形手术治疗严重先天性脊柱侧凸的临床疗效。方法严重先天性脊柱侧凸14例,男4例,女10例;年龄8～13岁,平均11.2岁。其中形成缺陷2例,分节缺陷6例,混合型6例。半椎体位于T53例,T2、T8、T10、T11、L1、L4各1例。胸弯12例,胸腰弯2例。术前冠状面Cobb角63°～95°,平均72.1°。胸椎后凸减小或前凸8例,胸腰段后凸4例。一期采用前路半椎体切除、多节段椎体间楔形截骨及分节不全松解;二期采用后路椎弓根钉棒系统三维矫形固定。前后路手术均植骨,平均截骨5.5个节段。结果一期前路术后冠状面Cobb角48°～60°,平均51.5°;矫正率19.6%～37.8%,平均28.6%。二期术后冠状面Cobb角5°～45°,平均30.5°;矫正率52.6%～87.5%,平均62.5%。8例存在胸椎后凸减小或前凸的患者均恢复生理性后凸,4例胸腰段后凸患者3例达到矢状面矫正。全部病例随访8～30个月,平均12.1个月。无断钉、断棒及明显的矫正度丢失,植骨融合良好。发生并发症2例,椎弓根钉帽松动1例,T1神经根激惹1例。结论一期前路半椎体切除、多节段椎体间楔形截骨、分节不全松解,二期后路矫形固定及前后路植骨治疗先天性脊柱侧凸能够达到较满意的矫形效果,适合于8～12岁的青春期前患者。     

青少年特发性脊柱侧凸的选择性胸椎融合治疗

目的　探讨青少年特发性脊柱侧凸选择性胸椎融合治疗的适应证。方法　回顾性分析12例行选择性胸椎融合患者术前、术后及随访时的X光像 ,对侧凸类型、侧凸Cobb角、顶椎旋转度、顶椎偏距、侧凸柔韧性、躯干偏移及胸腰段矢状面Cobb角进行测量和分析。患者 12例中男 2例 ,女10例 ,平均年龄 15 1(13～ 18)岁。侧凸均为KingⅡ型 ,其中PUMCⅡb1型 9例 ,Ⅱc3型 3例。所有病例均行选择性胸椎融合 ,平均随访 3 5 (1～ 10 5 )年。结果　手术前后胸弯冠状面Cobb角分别为5 4 0°、19 0° ,平均矫正率 6 2 7% ;腰弯冠状面Cobb角分别为 34 6°、12 5° ,自动矫正率为 6 4 7%。最后随访时 ,胸、腰弯的冠状面Cobb角分别为 18 8°、15 9°;腰弯冠状面Cobb角、顶椎偏距及顶椎旋转度与术后相比无显著变化。术后发生胸腰段后凸 1例 ,最终随访时未见进一步加重。无躯干失平衡现象发生。选择性胸椎融合较后路融合双弯平均减少 3 5个融合节段。结论　对腰弯柔韧性好且度数较小的KingⅡ (PUMCⅡb1和部分Ⅱc3)型特发性脊柱侧凸 ,可安全有效地行选择性胸椎融合     

胸腰段骨折前路与后路手术对侧方成角的影响

[目的]探讨胸腰段骨折前路与后路手术纠正脊柱侧方成角的效果。[方法]回顾分析本院自2007年1月~2011年6月胸腰段骨折手术患者117例,行前路手术者42例,行后路手术者75例。术后随访时间3~19个月,平均11.5个月,随访率91.4%,行术前、术后早期、末次随访时冠状位Cobb角测量并比较。[结果]对于术前冠状面Cobb角5°病例,前路手术术后冠状面Cobb角减小值较后路手术大(t=5.94,P0.05);对于术前冠状面Cobb角5°病例,前路手术较后路手术术后侧方畸形发生率更高(x~2=4.88,P0.05);前或后路手术患者如术后冠状面Cobb角小于10°,当其骨性愈合时冠状面Cobb角并未明显进展(P0.05);如术后冠状面Cobb角≥10°,其骨性愈合时冠状面Cobb角较前有进展(P0.05)。[结论]胸腰椎前路手术较后路手术能更好矫正侧方成角畸形,但也增加发生医源性侧凸畸形的风险;胸腰椎骨折术后出现或存留轻度侧凸畸形通常不会导致畸形持续进展,亦不产生明显临床症状,可以保守观察。     

不同手术入路对青少年特发性胸腰段/腰段脊柱侧凸矫形术后椎间角变化的影响

目的 分析比较青少年特发性胸腰段/腰段脊柱侧凸前路或后路矫形固定融合术后椎间角的变化.方法 回顾性分析此类患者接受前路(组A)或后路(组B)矫形固定融合手术前后侧凸Cobb角及椎间角的变化.结果 组A共30例患者,组B共12例患者.组A与组B术前、术后主弯冠状面Cobb角分别为48.9°和11.7°,44.3°和5.3°,矫形率分别为76.1%和87.7%.随访时冠状面Cobb角分别为18.1°和7.7°.术前、术后及随访时椎间角组A分别为3.2°、5.6°和8.2°,组B分别为3.3°、3.6°和3.2°.二组间比较,术后侧凸冠状面Cobb角、侧凸矫形率、随访时侧凸冠状面Cobb角、冠状面Cobb角丢失组B均优于组A(P=0.022,P:0.022,P=0.005,P=0.019);术后椎间角组A与组B比较差异无统计学意义(P=0.068),随访时椎间角组A较组B大(P=0.001),随访时椎间角丢失组A较组B多(P=0.043).结论 对于青少年特发性脊柱胸腰段/腰段侧凸,采用后路全椎弓根螺钉矫形固定融合手术随访时椎间角及椎间角丢失优于前路手术.     

胸腔镜下前路矫形治疗青少年特发性胸椎侧凸

目的探讨胸腔镜下前路矫形治疗青少年特发性胸椎侧凸的疗效。方法青少年特发性胸椎侧凸33例,男7例,女26例;年龄10～18岁,平均13.6岁。Lenke分型均为Ⅰ型,其中24例为ⅠA型,9例为ⅠB型。术前Cobb角:冠状面原发性胸弯平均57.4°(43°～68°),代偿性腰弯平均32.0°(20°～47°);27例存在胸椎后凸不足畸形,胸椎后凸平均6.3°(0°～18°)。手术方法为前路胸腔镜下切除椎间盘进行松解,应用CDHorizonEclipse矫形内固定,同时在椎间隙植骨。随访期间测量冠状面Cobb角及矢状面胸椎后凸成角,了解冠状面和矢状面畸形矫正情况。结果固定节段包括T4～T12,平均7.4个。平均手术时间为3h48min,平均术中出血量为308ml,平均住院时间4.4d。全部病例随访6～36个月,平均20.6个月。末次随访时原发性胸弯平均矫正60.2%,代偿性腰弯自然矫正平均50.3%,胸椎后凸平均矫正20.4°。1例出现假关节形成及内固定折断,2例出现胸壁麻木。结论胸腔镜下前路矫形治疗胸椎侧凸具有创伤小、术后恢复快等优点,能达到与开胸前路矫形术同样的矫形效果。     

经后路多点锚定技术治疗Ⅰ型神经纤维瘤病伴营养不良性脊柱侧凸的临床疗效

[目的]探讨经后路多点锚定技术治疗Ⅰ型神经纤维瘤病伴营养不良性脊柱侧凸的临床疗效。[方法]回顾性研究2005年1月~2013年12月本科收治的Ⅰ型神经纤维瘤病伴营养不良性脊柱侧凸23例;年龄10~22岁,平均13.6岁;其中胸弯13例,胸腰双主弯4例,胸腰弯3例,双胸弯2例,腰弯1例;术前冠状面Cobb角48.9°~91.4°,平均68.3°;凸侧Bending相Cobb角40°~79.2°,平均57.4°;柔韧性8.3%~28.1%,平均15.7%;顶椎旋转度2°~3°,平均2.3°;矢状面胸椎后凸Cobb角46.4°~79.6°,平均58.2°,胸腰段后凸Cobb角21.1°~35.7°,平均28.3°。均采用经后路多点锚定技术进行矫形融合固定。[结果]随访12~96个月,平均52个月。术后冠状面Cobb角16.3°~46.7°,平均28.4°;顶椎旋转度1°~2°,平均1.2°;矢状面胸椎后凸Cobb角16.1°~38.3°,平均25.3°,胸腰段后凸Cobb角-4.3°~18.7°,平均8.9°;术后各指标均获得良好的矫正,侧凸矫正率为46.3%~74.1%,平均56.9%。末次随访时侧凸矫正丢失率仅3.1%,无神经系统并发症,仅1例假关节形成。[结论]经后路多点锚定技术治疗Ⅰ型神经纤维瘤病伴营养不良性脊柱侧凸可获得较满意的矫形融合效果。     

合并胸腰段后凸的青少年特发性脊柱侧凸的临床研究

目的 探讨合并胸腰段后凸的青少年特发性脊柱侧凸(AIS)的临床特点和手术治疗策略. 方法对2001年1月至2007年1月收治的413例AIS患者进行回顾性分析,合并胸腰段后凸者共10例,其中男2例,女8例;年龄12～18岁,平均14.3岁.侧凸类型包括PUMC Ⅱb2型3例,Ⅱc 3型4例,Ⅱd2型1例,Ⅲb型2例.单纯后路内固定术8例,前路松解+后路内固定术2例.术前、术后及随访时摄X线片,对侧凸类型、Cobb角、顶椎旋转度、顶椎偏距、侧凸柔韧性、胸腰段后凸、冠状面及矢状面躯干偏移进行评测和分析.结果 本组患者中双弯8例,三弯2例;胸腰弯/腰弯Cobb角≥45°者7例,柔韧性指数≤70%者6例,顶椎旋转度≥Ⅱ度者9例.所有病例的融合范围均符合PUMC分型原则.手术前后平均胸弯冠状面Cobb角分别为71.7°和37.4°,平均矫正率为47.8%;手术前后平均胸腰弯/腰弯冠状面Cobb角分别为65.0°和27.8°,平均矫正率为57.2%;手术前后平均胸腰段后凸分别为35.5°和4.2°,平均矫正率为88.2%.全部病例随访12～72个月,平均23.1个月;最终随访时无躯干失平衡发生. 结论 合并胸腰段后凸的AIS一般多为双弯或三弯,胸腰弯/腰弯畸形往往比较严重,并有明显的旋转畸形.对合并胸腰段后凸的AIS,应融合胸腰弯/腰弯以防止术后发生失代偿或后凸加重, PUMC分型可以有效识别病变类型并指导融合范围的选择.     

胸腔镜辅助下治疗特发性脊柱侧凸

[目的]评价胸腔镜下前路松解,前路或后路矫形治疗特发性脊柱侧凸的治疗效果。[方法]回顾本院自2003年7月~2005年12月施行的11例胸腔镜辅助下前路松解,前路或后路矫形治疗特发性脊柱侧凸病例。年龄12~16岁,平均14.6岁。LenkeⅠ型9例,术前冠状面Cobb s角54°~68°,平均59.7°;LenkeⅢ型2例,术前冠状面Cobb s角分别为58°和71°,平均64.5°。Bending X线片侧凸矫正率为21.8%~32.4%,平均26.4%。对11例患者在胸腔镜辅助下,采用等离子冷消融切除椎间盘松解,前或后路矫正。对手术后及随访时,冠状面和矢状面的Cobb s角进行测量,并对手术时间,术中出血量,围手术期并发症及矫正丢失等进行分析。[结果]平均手术时间290 min,平均术中出血171 ml。松解节段5~7个,平均4.4个。9例LenkeⅠ型术后Cobb s角平均20.4°,Cobb s角矫正率平均65.8%;2例LenkeⅢ型术后Cobb s角分别为20°和25°,Cobb s角矫正率平均65.1%;1例术后包裹性胸腔积液,术后平均随访18.6个月;1例出现矫正度丢失14°,无神经系统及血管损伤并发症。[结论]与传统开胸前路胸椎侧凸矫形手术相比,胸腔镜辅助下胸椎松解前后路矫形治疗脊柱侧凸是安全有效的微创手术,可达到与开胸手术同样效果。     

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.     

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.     

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.