Topping-off技术治疗腰椎退变性疾病

目的 评价Topping-off技术治疗连续双节段腰椎退变性疾病的中期临床疗效及相关影像学改变.方法 2009年10月至2012年9月,采用Topping-off技术即后路腰椎椎间融合术(PLIF)联合Coflex棘突间动态固定装置置入术治疗18例连续双节段腰椎退变性疾病患者.男6例,女12例;年龄40～63岁,平均50.3岁;L5～S1融合和L4～5Coflex装置置入16例,L4～5融合和L3～4 Coflex装置置入2例.按照Oswestry 功能障碍指数(ODD、疼痛视觉模拟评分(VAS)、日本骨科协会(JOA)腰椎功能评分评价术前及术后随访时的临床疗效,计算恢复率.经X线片检测腰椎整体活动度(L2～S1 ROM)、Coflex装置置入节段活动度(ROM)及椎间盘高度指数(DHI),经MRI图像计算Coflex装置置入节段椎间盘髓核相对信号强度(RSI).结果 术后随访6～30个月,平均13.6个月.ODI由术前52.60±5.80降至末次随访时16.90±5.70,VAS由术前8.30±0.85降至末次随访时1.60±0.87,JOA腰椎功能评分由术前11.5±3.70提高至23.80±2.30,差异均有统计学意义(P＜0.001).18例患者术后恢复率评定均为显效,显效率为100％.L2～S1 ROM由术前20.10°±5.30°降至末次随访时16.30°±5.20°(P＜0.05),Coflex装置置入节段ROM由术前8.80°±1.90°降至末次随访时8.20°±1.80°(P＝0.19),DHI由术前0.25±0.03增加至末次随访时0.34±0.03(P＜0.001),RSI由术前0.701±0.058改善至末次随访时0.867±0.062(P＜0.01).结论 Topping-off技术治疗连续双节段腰椎退变性疾病可取得良好的中期疗效,Co flex装置对置入节段椎间盘修复及防止其退变的作用明显.     

腰椎Activ L人工椎间盘置换术后影像学表现与临床疗效的相关性分析

目的:探讨腰椎Activ L人工椎间盘置换术后的影像学表现与临床疗效的相关性。方法:2009年3月~2012年3月,应用Activ L假体对32例腰椎间盘退变性疾患的患者进行人工椎间盘置换术,其中30例患者共36个假体获得12~46个月(平均28.8个月)的随访,随访2年以上者20例(其中随访3年以上15例)。均在术前和末次随访时进行腰、腿痛VAS评分和Oswestry功能障碍指数(ODI)评分,同时测量手术节段和上、下相邻节段的活动度、椎间隙高度及腰椎前凸角。对术前及末次随访时的VAS评分、ODI评分,手术节段和上下相邻节段的活动度、椎间隙高度以及腰椎前凸角分别进行配对t检验,分别以每例患者末次随访时的VAS评分和ODI评分为应变量,以末次随访时的活动度、椎间隙高度以及腰椎前凸角为自变量,进行相关性分析。结果:末次随访时的腰痛VAS评分、腿痛VAS评分和ODI评分与术前比较均有显著改善(P0.0001)。末次随访时,手术节段、上位相邻节段活动度明显增加(P0.05),而下位相邻节段活动度无明显变化(P0.05);手术节段及其上、下相邻节段椎间隙高度与术前比较均无明显变化(P0.05);腰椎前凸角与术前比较无明显变化(P0.05)。末次随访时,手术节段、上下相邻节段的活动度和椎间隙高度及腰椎前凸角与VAS评分和ODI评分均无明显相关性(r0.2138,P0.05)。结论:腰椎Activ L人工椎间盘置换术治疗腰椎间盘退变性疾患的近中期疗效满意,近中期随访时手术节段、上下位相邻节段的活动度和椎间隙高度与临床疗效无明显相关性。     

腰椎单节段固定融合术后上位相邻节段退变及其与临床疗效的关系

目的:探讨腰椎单节段固定融合术后上位相邻节段退变及其与临床效果的关系,分析退变的相关因素。方法:回顾性分析2004年10月～2009年5月采用后路单节段椎弓根螺钉固定并椎体间cage植骨融合术治疗的49例L4/5退变性失稳患者,男22例,女27例,年龄28～72岁(平均53.4岁)。所有患者术前均行骨密度检测。在X线片上测量固定节段及其上位相邻节段椎间盘高度、椎间隙动态角度变化、椎体滑移距离以及固定节段和腰椎前凸角、腰骶关节角,并通过JOA评分及腰功能障碍指数(ODI)评价临床效果。根据末次随访时上位相邻节段有无影像学退变,分为退变组与非退变组,比较两组间临床效果及影像学测量结果。结果:随访时间为13～52个月,平均为29.3个月,所有患者术后均无神经损害加重症状。末次随访时11例患者(22%)出现上位相邻节段影像学退变。两组患者手术时的平均年龄有显著性差异(P<0.05);术前骨密度、腰椎前凸角、腰骶关节角、L4/5前凸角和椎体间滑移距离均无显著性差异(P>0.05);末次随访时L3/4椎体间滑移距离、L3/4椎间盘高度以及椎间隙动态成角变化值均存在显著性差异(P<0.05),ODI和JOA评分改善率无显著性差异(P>0.05)。患者年龄与末次随访时固定上位相邻节段椎间盘高度、椎间隙动态成角、椎体间滑移距离变化值存在正相关性,相关系数分别为0.353、0.521、0.472,余测量指标与固定上位相邻节段影像学指标变化均无显著相关性。结论:单节段腰椎固定融合术后上位相邻节段影像学退变与临床效果之间无显著相关性。此退变与患者年龄相关,而与骨密度和术前腰椎影像学测量指标无显著相关性。     

动态固定椎弓根螺钉在腰椎退行性疾病Topping-off手术中应用的早期临床疗效

目的:评价动态固定椎弓根螺钉在腰椎退行性疾病Topping-off手术中应用的早期临床疗效。方法 :2018年1月～2019年12月间在我院脊柱外科对43例因腰椎退行性疾病需要进行腰椎融合手术且相邻节段已出现影像学改变的患者通过动态固定椎弓根螺钉进行Topping-off手术,其中男性25例,女18例,平均年龄61±6岁(52～76岁);双节段手术32例,三节段手术11例;L2/3动态固定8例,L3/4动态固定19例,L4/5动态固定16例;头端动态固定39例,尾端动态固定4例。回顾性分析患者术前、术后的腰/腿痛疼痛视觉模拟评分(VAS)以及改良Oswestry功能障碍指数(ODI)以及动态固定节段与其相邻节段椎间盘改良Pfirrmann分级、椎间盘高度(DSH)和关节活动范围(ROM)等。结果:全组病例均顺利完成手术,术后随访时间均为12个月,均未出现神经损伤及内置物相关并发症;平均手术时间107±16min(90～150min),平均术中出血量平均280±72ml(200～450ml),平均住院时间9±2d(7～12d);腰/腿痛VAS和ODI术后、术后3个月及术后1年均较术前明显改善(P0.05);动态固定节段及其相邻节段椎间盘Pfirrmann分级在术前以及术后1年时均无明显差异(P0.05),但在术前动态固定节段椎间盘Pfirrmann分级低于或等于Ⅴ级时术前与术后1年椎间盘退变情况有差异(P0.05);动态固定节段及其相邻节段ROM、DSH在术前、术后3个月以及术后1年时均无明显差异(P0.05)。结论 :动态固定椎弓根螺钉在腰椎退行性疾病Topping-off手术中具有良好的早期临床疗效,能够保留腰椎融合术相邻节段一定的活动度,有效维持术后椎间隙高度以及椎间盘状态。     

Topping-off与融合固定治疗退行性腰椎疾病的临床疗效及邻近节段退变的对比研究

[目的]探讨Topping-off与融合固定治疗退行性腰椎疾病的临床疗效及对比性研究邻近节段的退变情况。[方法]回顾性研究2010年1月~2013年12月本院收治的99例L3~5退行性腰椎病变患者。根据手术方式不同,分为Topping-off组(L_(4~5)PLIF+L_(3~4)Coflex)45例,男21例,女24例,平均年龄61.50岁(46~77岁);融合固定组(L3~5PLIF)54例,男25例,女29例,平均年龄63.70岁(50~75岁)。记录手术时间、术中出血量及术后并发症。选用Oswestry功能障碍指数(Oswestry disability index,ODI)、视觉模拟评分(visual analogue scale,VAS)评价临床疗效。拍摄腰椎平扫MRI及站立位正侧屈伸位X线片,测量并记录术前、术后2年邻近节段L2-3椎间活动度及椎间盘MRI改良Pfirrmman分级,术前、术后2年Coflex置入节段L_(3~4)的椎间活动度,术后2年Topping-off组复合邻近节段活动度(Coflex置入节段L_(3~4)与其上位节段L_(2~3)椎间活动度之和)。[结果]平均随访时间(35.20±7.80)月(24~48月)。Topping-off组手术时间、出血量明显小于融合固定组(P<0.05)。术后2年腰痛及腿痛VAS、ODI评分与术前比较,两组均有明显好转(P<0.05)。术后2年L_(2~3)椎间活动度,与术前比较Topping-off组无明显变化(P>0.05),融和固定组明显增加(P<0.05);组间比较Topping-off组明显小于融合固定组(P<0.05)。术后2年Topping-off组复合邻近节段活动度与融合固定组L_(2~3)椎间活动度比较,差异无统计学意义(P>0.05)。术后2年腰椎MRI显示L_(2~3)椎间盘改良Pfirrman分级,Topping-off组明显优于融合固定组(P<0.05)。[结论]Topping-off对比融合固定治疗退行性腰椎疾病,具有创伤小、出血少、临床效果相似的特点,Coflex置入节段承担近端腰椎部分活动与应力,有助于减缓邻近节段的退变。     

Topping-off术后上位相邻节段的MRI表现及近期疗效

[目的]在MRI上观察采用Topping-off技术置入棘突间装置(Coflex)后椎间盘的退变情况,并评价近期临床效果。[方法]2007年8月~2014年11月,107例L5/S1间盘脱出合并L4、L5间盘退变,在本院行手术治疗并随访2年以上的患者纳入本研究。其中48例仅对L5S1行椎间融合术(融合组);59例采用Topping-off技术,L5、S1椎间融合术同时在L4、5棘突间置入Coflex(Topping-off组)。比较两组术前及随访时VAS、ODI及MRI上L4、5节段椎间盘相对信号强度(relative signal intensity,RSI)变化情况。[结果]融合组与Topping-off组患者临床症状均有显著改善,末次随访时两组的ODI及VAS评分均较术前明显下降,差异均有统计学意义(P<0.01),但相同时间点两组间的差异无统计学意义(P>0.05)。末次随访时MRI上Topping-off组L4、5节段椎间盘相对信号强度(RSI)显著高于融合组,两组间差异有统计学意义(P<0.05)。[结论]腰椎融合术及Topping-off技术对于伴节段不稳或伴有剧烈腰痛的腰椎间盘突出症均有良好且相似的临床疗效,但对于已合并上位邻近节段退变的患者,Topping-off技术缓解患者临床症状的同时更有助于延缓邻近节段椎间盘的退变。     

Coflex与融合治疗腰椎管狭窄症的中期疗效及对相邻节段退变影响的对比观察

[目的]对比分析棘突间动态非融合装置Coflex与腰椎后路融合固定治疗单节段腰椎管狭窄症的中期疗效,探讨Coflex在预防相邻节段退变中的作用。[方法]回顾性分析2009年12月~2012年6月应用棘突间动态非融合Coflex和椎弓根螺钉系统治疗L_(4、5)椎管狭窄症患者的临床资料,分为Coflex组和融合组。患者于术前及末次随访时进行视觉模拟评分(VAS)和Oswestry功能障碍指数评分(ODI)。对患者术前及术后随访时的腰椎侧位X线片及过伸、过屈侧位X线片和MRI片进行测量,用统计软件SPSS 18.0进行统计分析。[结果]Coflex组及融合组分别有20及22例患者被纳入本研究。两组患者术前性别、年龄、体质量指数及随访时间均匹配。两组VAS、ODI评分末次随访与术前相比差异均有统计学意义(P0.05),组间相比,差异无统计学意义(P0.05)。末次随访时,Coflex组L_(3、4)节段ROM与手术前无明显差异(P0.05),融合组L_(3、4)节段ROM末次随访(7.38±1.15)°比手术前增加(5.75±0.45)°,组间比较差异有统计学意义(P0.05)。末次随访两组L_(3~4)和L_5~S_1椎间隙高度与术前比较有降低趋势,但无统计学意义(P0.05)。Coflex组相邻节段椎间盘退变改良Pfirrmann分级,共有4例升高,融合组相邻节段椎间盘退变分级共有10例升高,组间差异有统计学意义(P0.05)。[结论]棘突间动态非融合Coflex治疗腰椎管狭窄症可达到与融合固定同样的中期临床疗效,并且在减少相邻节段退变方面具有一定优势。     

棘突间动态内固定装置治疗腰痛的临床应用评价

目的 评价采用Coflex棘突间动态内固定植入术治疗腰痛的临床疗效及相关影像学改变.方法 2007年2月至2009年6月,对45例患者行Coflex棘突间内固定植入术,男26例,女19例;年龄45～70岁,平均51.4岁.治疗节段:L4.5 32例,L5S111例,L4.5、L5S1双节段2例.手术采用椎板开窗或部分切除,椎管减压后棘突间植入Coflex装置.按照Oswestry功能障碍指数(Oswestry disabi1ity index,ODI)和日本矫形外科学会(Japanese Orthopaedic Association,JOA)评分评价术前及术后随访时的临床疗效,计算恢复率.同时行影像学观察,包括椎间隙高度和椎间孔形态,手术节段椎体活动度和腰椎生理曲度,手术及相邻节段的MRI信号改变.结果 术后随访时间1O-34个月,平均24个月.ODI由术前62.82±10.42降至末次随访时11.80±3.35;JOA评分由9.00±2.63提高至24.65±1.86;最终疗效评价为显效的患者共40例,显效率为89%.L4.5、L5S1节段术后Cobb角分别为15.1°±3.9°和16.3°±3.8°,均较术前减小,生理曲度改善.L4.5节段椎体活动度(range of motion,ROM)由术前6.5°±1.5°增加至术后8.4°±2.6°,而L5S1节段ROM手术前后没有明显改变.无论是L4.5或是L5S1节段,末次随访时其椎间隙背侧高度、棘突顶距、椎间孔高度和椎间孔面积均较术前显著增加.结论 Coflex棘突间动态内固定中期随访临床疗效显著,并且保留了腰椎生理曲度和节段运动,增加并维持椎间隙高度和椎间孔面积,在手术节段椎间盘修复及防止相邻节段椎间盘退变等方面作用显著.     

Dynesys非融合术后腰椎节段放射学改变及椎间盘再水化

[目的]分析Dynesys动态固定术后腰椎节段的放射学变化和残留椎间盘的再水化现象。[方法]回顾性分析2011年12月~2013年10月在本院接受Dynesys动态固定的38例腰椎间盘退行性疾病患者资料,记录患者术前,术后10 d,末次随访时VAS、ODI评分,采用腰椎X线片测量椎间隙前后缘高度、腰椎前凸角及屈伸活动度(range of motion,ROM),利用腰椎MRI计算手术节段椎间盘平均标准椎间盘信号(calibrated disc signal,CDS)。[结果]38例患者术后平均随访(25.11±6.96)个月。末次随访时,患者腰腿痛VAS评分和ODI指数较手术前后明显改善(P0.05)。手术节段椎间隙前、后缘高度较手术前后均明显降低(P0.05)。上位邻近节段椎间隙前缘高度与术前比较差异无统计学意义(P=0.47),后缘高度较手术前均显著下降(P0.05),平均丢失(10.34±9.81)%。下位邻近节段椎间隙前后缘高度及腰椎前凸角均无显著变化。手术节段屈伸ROM比术前明显减少(P0.05),但仍保留术前ROM的64.11%;相邻节段及腰椎整体ROM较术前差异无统计学意义。23例患者接受腰椎MRI复查,平均CDS由术前(42.74±13.15)%改善至(47.69±14.38)%,差异有统计学意义(P=0.004)。[结论]Dynesys非融合术后残留椎间盘出现再水化,表明其可能具有促进退变椎间盘修复的作用。该系统保留了固定节段一定ROM,不引起邻近节段过度活动。但是术后存在手术节段椎间隙高度丢失以及上位邻近节段代偿性前凸等问题。     

腰椎融合联合Coflex动态固定手术治疗腰椎退行性疾病

目的：总结腰椎后路椎间融合术联合Coflex动态固定术治疗腰椎退行性疾病的临床疗效。方法：对2008年3月至2010年3月应用腰椎后路椎间融合术联合Coflex动态固定治疗的18例腰椎退行性疾病患者（均为双节段）的临床资料进行回顾性总结分析。男11例,女7例;年龄41～62岁,平均50.2岁。分析内容包括：ODI指数、腰痛和下肢痛的VAS评分,并通过腰椎动力位X线观察活动度（ROM）、椎间隙高度（DHI）的变化情况。结果：所有患者获得随访,时间6～30个月,平均12个月。在末次随访时,腰痛VAS评分、下肢痛VAS评分及ODI指数均较术前明显改善（P〈0.001）。腰痛VAS评分术前（7.20±0.90）分,末次随访（1.50±0.90）分;下肢痛VAS评分术前（5.20±0.90）分,末次随访（1.10±0.80）分。ODI指数术前（52.50±5.90）%,末次随访（15.90±5.80）%。Coflex置入节段的DHI术前0.23±0.05,术后0.35±0.06,末次随访0.33±0.04,椎间隙高度未见明显丢失。Coflex置入节段的ROM术前（8.90±1.80）°,术后降至（8.30±1.90）°,末次随访（8.10±1.80）°,与术前差异无统计学意义（P=0.19）,Coflex置入节段活动度未见明显改变。L2-S1ROM术前为（20.20±5.60）°,术后（14.40±5.70）°,末次随访（15.50±5.20）°,与术前比较有统计学差异（P=0.01）。结论：腰椎后路椎间融合术联合Coflex动态固定治疗双节段腰椎退变性疾病能取得满意的中短期临床疗效,但没有充分证据证明这项技术优于多节段融合术。手术适应证的合理选择十分重要。     

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.