人工颈椎间盘置换的近期临床疗效和影像学分析

目的分析人工颈椎间盘置换治疗神经根型颈椎病的临床疗效和影像学改变。方法回顾2012年9月至2014年3月收治的行单节段人工颈椎间盘置换术的神经根型颈椎病患者30例,其中获得完整随访资料的21例,于术前及术后7 d、1个月、3个月、6个月行临床评估和影像学数据采集。使用Odom评级、疼痛视觉模拟评分(visual analogue scale,VAS)、日本骨科协会(Japanese orthopaedic association,JOA)评分及颈椎功能障碍指数(neck disability index,NDI)评分评估临床疗效及神经功能的改善情况,通过颈椎正侧位、动力位X线片观察颈椎整体、置换节段脊柱功能单位的曲度及活动度,以及置换节段相邻节段的活动度。结果 21例患者获得完整随访,随访时间6~9个月,平均6.8个月。NDI评分自术前(40±8.4)分下降到末次随访的(12±7.3)分(P0.05),JOA评分由术前(9±3.2)分提高到末次随访的(13.6±3.0)分(P0.05),上肢疼痛VAS评分由术前(7.6±1.6)分下降至末次随访(1.8±0.4)分(P0.05)。术后3个月颈椎曲度、置换功能节段曲度、颈椎活动度及置换功能节段的活动度较术前明显改善。术后3、6个月邻近节段活动度无明显改变。结论人工颈椎间盘假体行椎间盘置换术临床效果可靠,影像学资料显示术后可改善颈椎整体及置换节段曲度和活动度,保留临近节段活动度。     

单节段ProDisc-C颈椎人工椎间盘置换术对颈椎曲度和活动度的影响

目的:观察单节段ProDisc-C颈椎人工椎间盘置换术后置换节段活动度和颈椎曲度变化情况,分析ProDisc-C人工椎间盘置换术的效果.方法:2006年6月～2008年9月对53例颈椎病患者行单节段前路减压、ProDisc-C人工椎间盘置换术,置换节段C3/4 7例,C4/5 10例,C5/6 27例,C6/7 9例.应用医学影像存储与传输系统(PACS)测量术前和末次随访时置换节段活动度(ROM)、置换节段脊柱功能单位(functional spinal unit,FSU)Cobb角和颈椎整体曲度(C2～C7 Cobb角).结果:随访3～36个月,平均13.8个月.术前置换节段ROM为8.60°±3.7°,末次随访时为9.7°±3.5°,有统计学差异(P<.05);术前PSU Cobb角(前凸为正值)为0.1°±4.8°,末次随访时为3.6°±4.5°,有统计学差异(P<.05);术前颈椎整体曲度为7.0°±10.2°,末次随访时为8.0°±10.4°,无统计学差异(P>.05).结论:单节段ProDisc-C颈椎人工椎间盘置换术后置换节段活动度较术前增大,颈椎整体曲度无明显变化,FSU前凸增大,对于术前病变节段FSU生理前凸变小或轻度后凸的拟行颈椎人工椎间盘置换的患者可选择ProDisc-C假体.     

人工颈椎间盘置换的疗效及其对相邻非责任节段失稳的影响

目的:观察相邻非责任节段失稳颈椎病患者Bryan人工颈椎间盘置换术后的临床疗效及失稳节段的影像学变化。方法:2005年7月～2009年1月在我院行Bryan人工颈椎间盘置换术且术后随访36个月以上的43例颈椎病患者中,9例术前存在置换相邻节段失稳,男4例,女5例;年龄26～43岁,平均33.5岁。术前JOA评分为7～13(10.16±3.17)分,颈痛VAS为1～7(4.3±2.7)分。术前均经颈椎正侧位与屈伸动力位X线片及颈椎MRI证实存在手术相邻节段影像学失稳,但为非责任节段。C4/5置换、C5/6失稳1例;C5/6置换4例,其中C4/5失稳3例,C6/7失稳1例;C6/7置换、C5/6失稳2例;双节段置换2例:C4/5、C5/6与C5/6、C6/7各1例,均为头端相邻节段失稳。术后1周及术后3、6、12、24、36个月行JOA评分、颈痛VAS评分及Odom评分评估手术临床疗效;术前及术后3、6、12、24、36个月在颈椎动力位X线片上测量置换节段、失稳节段、颈椎整体活动度(C2～C7)及颈椎曲度。结果:术后1周JOA评分、颈痛VAS评分与术前比较无统计学差异(P>0.05),术后3、6、12、24、36个月JOA评分、颈痛VAS评分较术前明显改善,差异有统计学意义(P<0.05)。术后1周和3个月时Odom评分均为优6例、良1例、可2例,优良率为77.8%;术后6个月优6例、良2例、可1例,优良率为88.9%;术后12、24及36个月,Odom评分均为优7例、良1例、可1例,优良率为88.9%。术后3、6、12个月置换节段、失稳节段的活动度和颈椎曲度与术前比较差异无统计学意义(P>0.05);术后24、36个月,失稳节段的活动度较术前明显减小(P<0.05),置换节段活动度及颈椎曲度较术前明显增大(P<0.05);术后各时间点C2～C7活动度较术前无统计学差异(P>0.05)。随访期间未发现假体松动、移位及下沉。结论:Bryan人工颈椎间盘置换治疗颈椎病的短中期临床疗效良好,能逐渐改善年轻颈椎病患者置换相邻节段的影像学失稳。     

单节段Prestige LP人工颈椎椎间盘置换术在骨量减少颈椎病患者中的应用

目的 探讨骨量减少的颈椎病患者行单节段Prestige LP人工颈椎椎间盘置换术的安全性和有效性.方法 回顾性分析2012年2月—2017年6月本院采用Prestige LP人工颈椎椎间盘单节段置换术治疗的22例骨量减少的颈椎病患者临床资料.在术前,术后3 d、3个月、6个月、12个月及末次随访时采用日本骨科学会(JOA)评分评价患者神经功能,采用疼痛视觉模拟量表(VAS)评分及颈椎功能障碍指数(NDI)评估患者颈肩部疼痛及颈椎功能情况.在术前,术后3 d、3个月、6个月、12个月及末次随访时测量患者颈椎整体曲度、颈椎整体活动度(C2～7 ROM)、置换节段椎间角度、置换节段ROM(rROM)、置换节段椎间隙高度、置换节段脊柱功能单位(FSU)高度、邻近节段ROM(aROM)及邻近节段椎间隙高度等.观察并记录假体下沉、移位情况.结果 所有手术顺利完成.所有患者随访26～78个月,平均38.2个月.末次随访时所有患者JOA评分、VAS评分及NDI均较术前显著改善,差异有统计学意义(P<0.05).末次随访时置换节段椎间隙高度及FSU高度与术前相比显著增加,差异均有统计学意义(P<0.05).末次随访时颈椎整体曲度、C2～7 ROM、置换节段椎间角度、rROM、aROM及邻近节段椎间隙高度等与术前相比,差异均无统计学意义(P>0.05).至末次随访时,发生假体下沉3例,移位2例.结论 采用单节段Prestige LP人工颈椎椎间盘置换术治疗骨量减少的颈椎病患者安全有效,可维持满意的椎间隙高度和ROM,但需警惕假体下沉和移位等并发症.     

颈前路人工颈椎间盘置换术与Zero-p椎间植骨融合内固定治疗双节段脊髓型颈椎病的疗效比较

目的比较颈前路人工颈椎间盘置换术和Zero-p椎间植骨融合内固定治疗双节段脊髓型颈椎病的临床疗效。方法回顾性分析自2014-05—2019-05诊治的55例双节段脊髓型颈椎病,26例采用颈前路人工椎间盘置换术治疗(观察组),29例采用Zero-p椎间植骨融合内固定治疗(对照组)。比较2组手术时间、术中出血量、术后引流量、邻近节段退变数,比较2组末次随访时疼痛VAS评分、JOA评分、NDI指数、伤椎Cobb角、C_(2～7)活动度、C_(2～7)颈椎曲度、手术节段活动度、上位相邻节段活动度、下位相邻节段活动度。结果 2组均顺利完成手术并获得至少24个月的随访。2组手术时间、术中出血量、术后引流量比较差异无统计学意义(P0.05)。观察组术后出现邻近节段退变数较对照组少,差异有统计学意义(P0.05)。末次随访时2组疼痛VAS评分、JOA评分、NDI指数、伤椎Cobb角比较差异无统计学意义(P0.05),观察组C_(2～7)活动度、C_(2～7)颈椎曲度、手术节段活动度、上位相邻节段活动度、下位相邻节段活动度较对照组大,差异有统计学意义(P0.05)。结论颈前路人工颈椎间盘置换术和Zero-p椎间植骨融合内固定治疗双节段脊髓型颈椎病均能改善脊髓功能,增加颈椎活动度,颈前路人工颈椎间盘置换术在维持颈椎活动度、减少术后相邻节段退变等方面有一定优势。     

Prestige LP颈椎人工椎间盘置换治疗颈椎病的初期疗效

目的探讨应用Prestige LP人工椎间盘置换治疗颈椎病的初期疗效。方法采用Prestige LP人工颈椎间盘置换术治疗颈椎病14例,统计并分析患者术前和术后随访时相关指标并进行比较。结果所有患者均为单节段置换,术后随访平均15.6个月。术后JOA评分由(10.3±2.1)分提高到(15.2±4.4)分,NDI评分由(42.30±10.15)%改善到(16.54±8.16)%,颈部疼痛VAS评分由(5.2±1.4)分改善到(1.6±0.7)分,上肢疼痛由(5.3±1.7)分改善到(1.7±0.8)分,差异均有统计学意义(P<0.05);术后患者生存质量明显改善,SF-36中物理评分从(34.2±5.1)%改善至(52.3±6.5)%,心理评分从(39.2±3.7)%改善至(55.3±4.6)%(P<0.05)。术后手术节段颈椎曲度由(7.1±2.4)°改善至(12.8±3.1)°(P<0.05),颈椎的整体曲度由前(15.7±5.3)°改善至(17.1±6.0)°(P>0.05);手术前后手术节段活动度、手术节段邻近节段活动度无明显变化(P>0.05)。结论应用Prestige LP人工椎间盘置换术治疗颈椎病初期临床疗效良好,中远期疗效有待进一步观察。     

双节段BRYAN人工颈间盘置换的中期疗效分析

[目的]观察相邻双节段BRYAN人工颈椎间盘置换术治疗相邻节段颈椎病的临床疗效与影像学结果.[方法]回顾2006年1月～ 2009年2月在本院行相邻双节段BRYAN人工颈椎间盘置换术并获得随访的颈椎病患者19例.术前及术后1周,术后3、6、12、24、36个月进行JOA评分、NDI评分及颈痛VAS评分,评估手术临床疗效;术前及术后3、6、12、24、36个月通过颈椎动力位X线片评定置换节段、上下相邻节段和C2-7颈椎活动度;术后12、24、36个月,通过X线椎间盘退变评分系统评估手术相邻节段退变.[结果]所有患者术后神经症状均明显好转,各随访点JOA评分、NDI评分、颈痛VAS评分较术前显著改善,差异有统计学意义(P＜0.05),3个月后各随访时点两两比较差异无统计学意义(P＞0.05).两置换节段活动度术后各随访点与术前比较差异有统计学意义(P＜0.05);3个月后随访,上下相邻节段活动度与术前相比略减小,C2-7活动度较术前略增加,差异无统计学意义(P＞0.05).至末次随访时,手术未导致相邻节段椎间盘退变加剧,无严重并发症发生.[结论]BRYAN人工颈椎间盘置换治疗相邻双节段颈椎间盘退变性疾病临床疗效良好,不仅保留了颈椎的运动学特性,防止置换节段与相邻节段退变,而且术后近中期无严重并发症.     

单节段ProDisc-CDisc-C人工颈椎间盘置换术后旋转中心的位置变化

目的探讨单节段Pro Disc-C人工颈椎间盘置换术的临床疗效以及术后置换节段屈伸活动旋转中心(center of rotation,COR)的位置变化及其临床意义。方法回顾分析2010年6月-2012年2月收治的23例行单节段Pro Disc-C人工颈椎间盘置换术患者临床资料。男9例,女14例;年龄27~65岁,平均45岁。病程10~84个月,平均25个月。其中神经根型颈椎病15例,脊髓型颈椎病5例,混合型颈椎病3例。病变节段:C4、5 5例,C5、6 14例,C6、7 4例。采用日本骨科学会评分(JOA)及颈椎功能障碍指数(NDI)评价临床疗效;比较术前和末次随访时颈椎整体活动度、置换节段及相邻节段活动度、椎间隙高度以及置换节段屈伸活动COR位置坐标(COR-X,COR-Y)的变化;比较分析COR位置变化与术后临床疗效以及影像学指标之间的关系。结果 23例患者均顺利完成手术,其中1例术后出现声嘶,术后3个月症状消失。患者均获随访6~36个月,平均18.3个月。末次随访时假体无移位、松动、下沉及断裂。末次随访时JOA评分较术前显著增加,NDI评分较术前显著减少,差异均有统计学意义(P0.05)。与术前比较,末次随访时颈椎整体活动度,置换节段活动度,上、下相邻节段活动度以及置换节段COR-Y差异均无统计学意义(P0.05);椎间隙高度、置换节段COR-X显著增加(P0.05)。置换节段COR-X变化与术后JOA、NDI、置换节段活动度均无明显相关性(P0.05)。根据手术前后COR-X之差是否小于均值1.86 mm将患者分为两组,两组间术后置换节段活动度差异有统计学意义(P0.05),而两组间术后JOA、NDI、颈椎整体活动度、邻近节段活动度及椎间隙高度差异均无统计学意义(P0.05)。结论单节段Pro Disc-C人工颈椎间盘置换术临床疗效满意,能有效维持颈椎整体活动度、置换节段和相邻节段活动度,增加置换节段的椎间隙高度。术后置换节段矢状面COR位置较术前显著前移,且术后置换节段活动度随COR前移距离增大而减小。     

Mobi-C人工颈椎间盘置换的临床疗效和影像学分析

[目的]分析Mobi-C人工颈椎间盘置换治疗颈椎病的临床疗效和影像学改变,探讨其重建或保留椎间高度及颈椎整体、置换节段、临近节段活动度的作用.[方法]回顾2009年10月～ 2010年6月本科收治的行Mobi-C单节段人工颈椎间盘置换术的颈椎病患者31例,其中获得完整随访资料的22例.于术前、术后7d,术后1、3、6、12、24个月行临床评估和影像学数据采集.使用Odom评级、VAS评分、JOA评分、NDI评分评估临床疗效及神经功能的改善情况;通过颈椎正侧位、动力位X线片观察椎间高度及颈椎整体、置换节段、临近节段、脊柱功能单位(FSU)的活动度.[结果]22例患者获得完整随访,随访时间24 ～30个月,平均26.3个月.与术前相比,24个月随访时,VAS评分、JOA评分、NDI评分均有改善(P＞0.05).术后颈椎活动度、FSU活动度、置换节段及临近节段活动度维持了术前水平.置换节段椎间高度均有恢复,上下临近节段椎间高度维持术前水平.[结论]使用Mobi-C人工颈椎间盘假体行椎间盘置换术临床效果可靠,影像学资料显示术后可重建或保留椎间高度及颈椎整体、置换节段、临近节段活动度.     

Bryan颈椎人工椎间盘置换术后5年随访结果

目的:观察Bryan颈椎人工椎间盘置换术后5年随访结果。方法:我院从2003年12月开展Bryan颈椎人工椎间盘置换术,术后达到5年的患者共70例,其中57例获得57～69个月(平均60个月)随访。单节段置换47例,双节段置换9例,3节段置换1例。C3/4 5例、C4/5 10例、C5/6 45例、C6/7 8例。术前和末次随访时进行mJOA、VAS、NDI评分,末次随访时进行Odom′s分级评估临床疗效;术前和末次随访时,在过伸过屈侧位X线片上测量置换节段活动度,在侧位X线片上采用McAfee异位骨化分级方法评定异位骨化情况,在MRIT2加权像上采用Miyazaki颈椎间盘退变分级方法评定相邻节段椎间盘退变情况,在MRI中矢状位T2加权像上测量相邻节段突出椎间盘对椎管的侵占率。结果:(1)mJOA评分术前为13.4±1.9分,末次随访时16.1±1.1分,平均改善率为75.0%;上肢痛VAS评分术前为3.3±1.9分,末次随访时0.9±1.2分;颈肩痛VAS评分术前为3.0±1.5分,末次随访时1.6±1.4分;NDI评分术前为14.8±8.6分,末次随访时5.7±4.2分;以上指标末次随访时与术前比较均有统计学差异(P<0.05)。末次随访时Odom′s分级优21例,良27例,可7例,差2例。(2)28例患者获得X线随访,术前置换节段活动度为6.9°±3.0°,末次随访时为7.2°±3.7°,无统计学差异(P>0.05);末次随访时,30个手术节段中12个(40%)出现异位骨化,其中3个(10%)节段丧失活动度。(3)25例患者获得MRI随访,末次随访时50个相邻节段中7个(14%)椎间盘退变分级加重1级,但无相关临床症状出现;相邻节段突出椎间盘对椎管侵占率的年度平均增幅为0.3%～0.5%。结论:Bryan颈椎人工椎间盘置换术后平均5年随访的临床和影像学结果满意,手术节段活动度得到较好保留,相邻节段退变发生率较低,无相邻节段疾病发生。     

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.     

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.     

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.