颈后路侧块螺钉内固定术中曲度矫正对改善术后颈椎轴性症状的临床研究

目的探讨颈椎后路侧块螺钉内固定术中曲度矫正对术后颈椎曲度、椎间隙高度及轴性症状产生的长期影响及临床意义。方法自2009-05-2012-01,回顾性分析70例多节段脊髓型颈椎病患者,A组34例患者行常规颈后路椎板减压侧块螺钉内固定术。B组36例患者行颈后路椎板减压侧块螺钉内固定术并在C型臂X线机透视下进行颈椎曲度及高度矫正。对两组患者手术前后的JOA评分、颈椎曲度指数及轴性症状评分进行比较评估。结果两组患者JOA评分恢复率、颈椎曲度丢失情况对比,差异无统计学意义(P0.05)。两组有明显轴性症状的患者比例方面,差异有统计学意义(P0.05)。结论颈后路椎板减压侧块螺钉内固定术中,应用C型臂X线机透视进行颈椎曲度及高度矫正临床效果良好,可明显恢复颈椎生理曲度、适当恢复椎间隙高度、改善患者术后轴性症状。     

颈椎后路减压术后脊髓后移的临床意义

[目的]探讨颈后路减压术后脊髓后移位对多节段脊髓型颈椎病(cervical spondylotic myelopathy,CMS)的临床意义.[方法]2003年7月～2008年6月,回顾性分析65例多节段脊髓型颈椎病患者,其中,男41例,女24例;年龄40～75岁,平均58.4岁.行颈后路单开门椎管成形减压术后通过MRI比较其术前及术后的脊髓后移位距离.根据患者术后脊髓后移位的距离不同将其分为三组(A≤2 mm;2 mm＜B＜4 mm;C≥4 mm),对三组患者手术前后的JOA评分、颈椎曲度指数的丢失程度(curvature index,CI)及轴性症状(axial symptom,AS)的严重程度进行比较评估.[结果]随访时间24～55个月,平均31个月.JOA评分恢复率,A组患者为63.1哂±16.9%,B组患者为59.5%±22.3%,C组患者为54.3%±9.8%,三组差异无统计学意义.A组患者术后颈椎曲度丢失指数为3.2%±2.4%,B组患者为3.1%±2.7%,C组为4.2%±3.1%,三组患者手术前后颈椎曲度的变化差异无统计学意义.A组术后有明显轴性症状患者的比例为18.2%,B组为36.7%,C组为53.8%,三组比较差异有统计学意义(P＜0.05).[结论]颈后路椎板切除术后脊髓后移位程度与病人术后恢复程度无明显关联.脊髓后移距离与术后曲率指数亦无明显关联.脊髓后移位与术后轴性症状的程度存在相关性.     

两种颈后路单开门手术方法对颈椎曲度指数及活动度的影响

[目的]探讨两种颈后路单开门手术方法对术后患者神经功能改善率、颈椎曲度指数、颈椎活动度的影响及其临床意义.[方法]自2008年6月～2011年9月,78例脊髓型颈椎病患者接受颈后路单开门椎管扩大成形术.A组41例患者行改良术式,即保留颈半棘肌肌止,切除C3椎板,C4-7“锚定法”单开门椎管扩大成形术.B组37例患者行传统C3-7单开门椎管成形术.计算两组患者神经功能改善率及术前术后颈椎曲度指数、颈椎活动度的变化,研究两组间差异.[结果]两组患者术后神经功能改善恢复率,A组为(57.5±19.4)％,B组为56.3±19.8％,两组间差异无统计学意义,术后颈椎曲度指数丢失百分比,A组丢失(2.86±2.44)％,B组丢失(5.31±2.12)％,B患者手术前后颈椎曲度指数丢失明显多于A组.术后颈椎活动度,A组患者术后丢失(8.27±5.03).,B组患者术后丢失(11.06±6.97)°,两组差异有统计学意义(P＜0.01).[结论]保留颈半棘肌肌止,C3椎板切除,C4-7“锚定法”单开门椎管扩大椎管成形术,与传统术式相比具有同样的神经功能改善率,同时能有效防止颈椎曲度指数及颈椎活动度的丢失.     

颈后路椎管扩大减压微型钛板固定椎板成形术与传统颈椎后路单开门椎管扩大减压术治疗颈椎病的比较研究

[目的]比较观察研究颈后路椎管扩大减压微型钛板固定椎板成形术与传统颈椎后路单开门椎管扩大减压术治疗颈椎病的临床疗效。[方法]回顾分析32例脊髓型颈椎病患者的临床资料,按手术方式随机分为2组,其中观察组为微型钛板组16例,对照组为传统单开门组16例,对比分析两组患者手术情况、术后症状改善情况JOA评分,末次随访术后椎板开门角度,术后测量颈椎曲度(颈椎侧位X线片上C2与C7椎体后壁切线之间夹角)的改变,以及轴性症状发生率,观察手术时间、术中出血量对比情况。[结果]经术后6个月²年的随访,微型钛板固定组术后6个月JOA评分改善率为60.5%±17.0%,传统单开门组为58.2%±9.5%,两组比较差异无统计学意义(P>0.05)。微型钛板固定组末次随访时椎板开门角度为(42.3±3.5)°,传统单开门组为(39.5±4.1)°,两组比较差异无统计学意义(P>0.05)。微型钛板固定组术后6个月颈椎曲度为(18.5±4.8)°,与术前(18.2±4.8)°比较差异无统计学意义(P>0.05);传统单开门组术后6个月颈椎曲度为(16.9±5.6)°,与术前(19.5±6.2)°比较差异有统计学意义(P<0.05);微型钛板固定组术后6个月轴性症状发生率为4/16,明显低于传统单开门组的9/16,两组比较差异有统计学意义(P<0.05);两组患者无1例出现C5神经根麻痹。[结论]颈后路椎管扩大减压微型钛板固定椎板成形术和传统颈椎后路单开门椎管扩大减压术均是治疗脊髓型颈椎病的有效方法,但颈后路椎管扩大减压微型钛板固定椎板成形术更有效防止单开门椎管扩大椎板成形术后再关门,减少术后轴性症状的发生率和颈椎曲度的丢失,是治疗颈椎病的一种理想手术方式。     

两种颈后路术式治疗多节段脊髓型颈椎病术后C_5神经根麻痹分析

目的回顾分析两种颈后路手术术后C5神经根麻痹的发生与预后。方法回顾性分析自200-08-2011-01期间行手术治疗并获得随访的166例脊髓型颈椎病患者的临床资料,单纯行颈椎后路单开门椎管扩大成形术84例(A组):其中多节段椎间盘突出脊髓型颈椎病37例,发育性椎管狭窄28例,后纵韧带骨化19例。同期行颈椎后路全椎板切除、椎间孔扩大减压联合侧块螺钉内固定术82例(B组):其中多节段椎间盘突出脊髓型颈椎病39例,发育性椎管狭窄24例,后纵韧带骨化19例。记录术后C5神经根麻痹的发生情况,其诊断标准为:在无脊髓原有症状加重的情况下,颈椎管减压术后出现三角肌和/或肱二头肌肌力下降,伴或不伴肩部感觉减退或消失。结果两组术后神经功能改善率方面组间比较差异无统计学意义(P0.05)。两组术后颈椎曲度改变率以及术后C5神经麻痹发生率方面组间比较差异有统计学意义(P0.05)。结论颈椎后路全椎板切除联合侧块螺钉内固定术中,对椎间孔的减压降低了术后C5神经根麻痹的发生率。     

C3椎板切除并保留C7棘突的颈椎管扩大双开门成形术

[目的] 对传统C3～7椎板成形术进行改良,观察改良手术疗效,探讨其能否有效降低并发症的发生.[方法] 改良椎板成形术治疗脊髓型颈椎病20例(A组),A组患者平均年龄65.7岁(45～83岁);男14例,女6例;平均随访时间为18个月(12～27个月).传统术式对照组(B组)为本院同期行传统C3～7椎板成形术的18例患者,B组患者平均年龄59岁(46～75岁);男11例,女7例;平均随访时间为25 个月(12～50个月).对两组患者手术前后的JOA评分、颈椎曲度角度、颈椎活动度及轴性症状严重程度进行比较评估.[结果] JOA评分恢复率,A组患者为46.5%,B组患者为54.1%,两组差异无统计学意义( P>0.05).A组术后有明显轴性症状患者的比例为10%,B组为44.4%,两组比较差异有统计学意义(P<0.05).A组患者术后颈椎曲度Cobb's角11.2°±9.2°,B组患者术后颈椎曲度Cobb's角10.9°±10.1°,A组和B组患者手术前后颈椎曲度的变化差异无统计学意义(P>0.05).A组患者术后颈椎活动度丢失6.9°±4.0°,B组患者术后颈椎活动度丢失11.6°±7.8°,两组差异有统计学意义(P<0.01).[结论] C3椎板切除保留C2棘突半棘肌附着、同时保留C7棘突颈背肌肉附着的颈椎管扩大椎板成形术能获得良好神经减压效果,同时可以最大程度维持颈半棘肌和颈背肌结构和功能的完整性,减少对颈椎后伸机制和颈椎稳定机制的破坏,从而保留颈椎的活动度和降低术后颈椎轴性症状的发生.     

颈椎管成形术与椎板切除内固定术后C5神经根麻痹比较

目的 比较颈后路单开门椎管成形术与椎板切除内固定术治疗多节段脊髓型颈椎病术后颈5(C5)神经根麻痹的发生率,并分析其原因.方法 2005年1月至2010年6月,因多节段颈脊髓病变分别接受椎管成形术的患者27例(A组):男21例,女6例;年龄33～80岁,平均60.4岁;减压3～6个节段.同期接受椎板切除内固定术的患者41例(B组):男31例,女10例;年龄22～77岁,平均58.7岁;减压3-6个节段.术后随访12～46个月(平均22个月);两组手术前后以Cobb法测量颈椎前凸角度,以Ishihara法测定颈椎曲度指数(cervical curvature index,CCI),并记录术后C5神经根麻痹的发生情况.比较B组中9例C5神经根麻痹患者(B1组)与32例无C5神经根麻痹患者(B2组)的手术前后颈椎前凸角度及CCI.结果 A组C5神经麻痹发生率为3.7％( 1/27),B组发生率为22.0％(9/41),差异有统计学意义(x2=4.32,P＜ 0.05),10例C5神经根麻痹患者平均于术后14个月肌力恢复至4级以上.B1组手术前后CCI改变率为38.07％±18.03％,B2组为22.81％±12.71％,两组差异有统计学意义(t=2.88,P＜0.05).结论 相比颈后路椎板切除内固定术,椎管成形术后C5神经根麻痹发生率低.C5神经根麻痹可能与颈后路术后颈椎前凸增加有关,神经根拴系效应是其重要的发病机制之一.     

颈椎曲度及椎间高度变化对颈后路减压术后疗效的影响

 目的探讨颈椎曲度及椎间高度的变化对颈后路减压术治疗多节段脊髓型颈椎病疗效的影响。方法选取2006年7月至2009年1月行手术治疗的多节段脊髓型颈椎病(≧3个节段)患者50例为研究对象,分为侧块螺钉内固定组(侧块组)26例,单开门组24例,回顾性分析颈椎曲度和椎间高度的变化对术后疗效[日本骨科协会评分(Japanese Orthopaedic Association Scores,JOA)改善率和颈部疼痛视觉模拟评分(visual analog scale,VAS)]的影响。结果所有患者均获得8个月~4年随访,平均(24.0±5.5)个月。侧块组术前颈椎曲度与术后3天比较,差异有统计学意义;单开门组同期比较,差异无统计学意义。侧块组术后3天颈椎曲度与术后6个月、术后3年比较,差异无统计学意义;单开门组同期比较,差异有统计学意义。侧块组术后3年JOA评分改善率优于单开门组,差异有统计学意义。进一步以颈椎曲度及椎间高度丢失程度为标准进行分组分析显示,颈椎曲度和椎间高度低度丢失组术后3年JOA评分改善率及颈部VAS评分均优于高度丢失组,差异有统计学意义。结论颈椎后路全椎板减压侧块螺钉内固定能够改善术后颈椎曲度及保持术后椎间高度,能有效地降低轴性症状的严重程度及提高中期JOA评分改善率。     

颈椎后路三种手术方式对改善多节段颈椎病生理曲度及疗效的远期观察

[目的]本研究通过回顾性分析行颈椎后路手术的多节段脊髓型颈椎病合并后纵韧带骨化(ossificationofposteriorlongitudinalligament.OPLL)患者的颈椎曲率变化、JOA评分改善率以及颈肩轴性痛VAS评分改善率,比较颈椎后路三种手术方式对改善颈椎曲度、神经功能及轴性症状的远期影响.[方法]根据手术方式分三组:A组颈椎后路单开门椎管扩大成形术29例,B组颈椎后路全椎板切除术23例,C组颈椎后路全椎板切除侧块螺钉内固定术26例,记录术前、术后的颈椎曲度、JOA评分及轴性症状等.[结果]JOA评分改善率:3组患者术后与术前相比均有统计学意义(P＜0.05).末次随访时c组最高.颈椎曲度改善率:C组最好,A组次之,B组最差.并发症发生情况:在轴性症状上,3组的VAS评分两两比较有统计学意义(P＜0.05),B组最高,A组次之,C组最低.[结论]采用颈椎后路三种手术方式治疗多节段脊髓型颈椎病合并OPLL均能达到良好的疗效.颈椎后路全椎板切除侧块螺钉内固定术可有效改善神经功能,恢复和保持颈椎曲度,降低轴性症状及C5神经根麻痹发生率.     

颈椎后路改良单开门椎管扩大成形术治疗多节段脊髓型颈椎病的疗效分析

目的 :探讨颈椎后路改良单开门椎管扩大成形术治疗多节段脊髓型颈椎病的临床效果。方法 :回顾性分析2013年6月~2015年12月采颈椎后路单开门椎管扩大成形术治疗并获得随访的多节段脊髓型颈椎病患者,均采用相同的微型钛板固定单开门椎板,其中21例(男17例,女4例,年龄66.2±10.0岁)采用改良单开门椎管扩大成形术(改良组),39例(男36例,女3例,年龄57.3±10.5岁)采用传统单开门椎管扩大成形术(传统组),收集两组患者手术时间、术中出血量、术后住院时间、手术费用,随访两组患者神经功能改善情况、颈椎曲度、颈椎曲度指数、颈椎活动度及轴性症状等,并进行比较。结果:两组患者性别、年龄、病程、手术时间、术中出血量、术后住院时间均无显著性差异(P0.05),两组手术费用比较有显著性差异,改良组平均手术费用明显低于传统组(P0.05)。术后随访12~24个月,术后12个月两组患者均达到骨性融合,两组神经功能均明显改善,JOA评分改善率改良组为(60.46±9.65)%,传统组为(46.41±24.33)%,两组比较无显著性差异(P0.05)。改良组术后12个月时颈椎曲度丢失4.7°±1.9°,颈椎曲度指数丢失(3.09±.14)%,颈椎活动度丢失7.3°±2.3°;传统组颈椎曲度丢失8.9°±5.6°,颈椎曲度指数丢失(6.27±3.42)%,颈椎活动度丢失13.0°±3.9°,两组比较均有显著性差异(P0.01)。改良组术后出现轴性疼痛症状患者3例,传统组为19例,两组比较有显著性差异(P0.01)。随访期间两组均无再关门发生,两组均无钛板、螺钉松动移位。结论:与颈椎后路传统单开门椎管扩大成形术相比,改良单开门椎管扩大成形术在获得良好神经减压效果的同时,可减少手术费用,降低术后颈椎轴性症状的发生率,有利于颈椎曲度和颈椎活动度的维持。     

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.