颈椎病椎板成形手术疗效及相关影响因素分析

目的 :观察脊髓性颈椎病 (cervicalspondyloticmyelopathy ,CSM )后路手术疗效 ,进而探讨相关影响因素。方法 :随访 2 5例行“单开门”椎板成形术 (open doorlaminoplasty ,ODLP)CSM病例 ,依据临床功能改善率分为疗效优良组和一般组 ,统计并比较各组临床及影像学资料 ,观察各因素与ODLP术后疗效的相关性。结果 :①手术前后及随访时临床JOA分值分别为 8.6 0± 2 .93、11.5 2± 2 .71、12 .5 2± 3 .15 ,呈明显增加趋势。②优良组中患者手术时年龄、病程明显短于一般组 ,手术前后JOA分值及术前最狭窄处脊髓面积明显大于一般组。③优良组中后突畸形、颈椎不稳及髓内信号改变者少于一般组。④术前椎管面积 <10 0mm2 或术后 <16 0mm2 时 ,预后较差 ;而当术前椎管面积 >12 0mm2 或术后 >2 0 0mm2 时 ,预后较好。结论 :①ODLP是较为成熟的外科技术 ,疗效满意。②患者年龄、病程、术前病情及受压脊髓面积是决定术后疗效的主要因素。③颈椎曲度、术前颈椎稳定性、髓内信号改变、手术前后椎管面积亦为判断预后的重要指标。     

甲基强的松龙在发育性颈椎管狭窄合并脊髓型颈椎病围手术期的应用

目的探讨围手术期预防性应用甲基强的松龙(MP)对发育性颈椎管狭窄(DCS)合并脊髓型颈椎病(CSM)患者脊髓减压术后神经功能恢复的影响.方法62例DCS合并CSM患者,根据围手术期是否应用MP分为2组,MP组32例,术中脊髓减压前30min以MP 30mg/kg静滴(15min内滴完),45min后继以5.4mg/kg/h维持用药23h;对照组30例,术中脊髓减压前给予地塞米松15mg静脉点滴,术后地塞米松10mg静滴×3d.术后3d、7d、1个月、6个月和12个月按JOA评分标准评定两组患者的神经功能改善率[(术后JOA评分-术前JOA评分)/(17-术前JOA评分)×100%],观察统计并发症.结果术后3d两组患者神经功能改善率比较无显著性差异(P＞0.05),术后7d时MP组与对照组神经功能改善率分别为(68.43±9.89)%、(49.67±11.45)%,有显著性差异(P＜0.05),术后1个月时分别为(77.32±11.24)%、(61.65±10.42)%(P＞0.05),术后6个月时分别为(81.12±10.42)%、(70.45±9.22)%(P＜0.05),术后12个月时分别为(83.15±8.57)%、(81.77±11.61)%(P＞0.05).术后对照组有4例出现肩痛,MP组无严重并发症出现.结论DCS合并CSM患者围手术期预防性应用MP能提高手术的安全性及术后近期神经功能改善率,未增加严重不良反应的发生.     

两种翻修术式治疗寰枢椎后路复位不足病例的临床疗效比较

【摘要】 目的：研究难复性寰枢关节脱位（irreducible atlantoaxial dislocation,IAAD）患者因寰枢椎术后复位不足而进行翻修手术的临床效果。方法：回顾性分析2000年4月～2021年8月因寰枢椎复位不足产生神经压迫症状而接受翻修手术患者的临床资料,根据翻修术式不同分为两组：A组（经口齿状突切除术）和B组（“后前后”联合入路,即后路内固定拆除及植骨块截骨、前路经口咽寰枢松解复位、再次后路固定融合术）。研究本组病例手术前后的脊髓功能的变化、住院时间、手术时间及术中出血量,手术过程有无并发症及并发症的种类和数量,手术前后延脊髓角（cervicomedullary angle,CMA）的大小。其中脊髓功能采用日本骨科协会（Japanese Orthopaedic Association,JOA）评分评价,脊髓功能的改善率（JOA改善率）= [（治疗后评分-治疗前评分）/（17-治疗前评分）]×100%。寰枢关节脱位的影像学改善率用延脊髓角改善率[CMA改善率=（术后角度-术前角度）/术前角度×100%]表示,并在组间进行对比研究。结果：32例因寰枢椎复位不足行翻修术的IAAD患者术前均存在脊髓病,其中A组14例,B组18例。A组术前JOA评分13.00±1.96分,术后末次随访JOA评分15.54±1.08分,术前CMA 132.66°±9.36°,术后末次随访CMA 144.74°±11.18°,住院时间21.93±14.07d,手术时间211.43±92.64min,术中出血量279.29±345.17mL。B组术前脊髓功能JOA评分11.78±3.23分,术后末次随访JOA评分14.97±1.47分,术前CMA 126.28°±11.06°,术后末次随访CMA 154.71°±6.50°,住院时间35.83±26.19d,手术时间368.83±118.55min,出血量534.50±324.66mL。A组翻修手术并发症率为57.1%,JOA改善率为（68.00±15.16）%,CMA改善率为（9.23±6.23）%;B组翻修手术并发症率为33.3%,JOA改善率（63.59±10.89）%,延脊髓角改善率（23.21±9.83）%。A组的手术时间及术中出血量显著低于B组,而两组的住院时间无显著差异性。B组的CMA改善率显著优于A组,而两组的脊髓病改善率（JOA改善率）及翻修手术的并发症发生率无显著差异。结论：寰枢椎后路复位不足病例的翻修术并发症较高、临床疗效较差。后前后联合手术相对于经口齿状突切除术的CMA改善率较优,其最大的优势在于解除脊髓压迫的同时可完全恢复颈椎力线。初次手术应做到寰枢解剖复位,尽量避免在寰枢复位不足状态下实行固定融合术。     

体感诱发电位监测在腰椎管狭窄症斜外侧椎间融合术中的应用

【摘要】 目的：探讨术中体感诱发电位（SEP）监测在退行性腰椎管狭窄症斜外侧椎间融合（OLIF）术中的应用价值。方法：选择2017年7月～2019年2月在宁夏医科大学总医院采用OLIF联合Wiltse入路单侧椎弓根螺钉固定术治疗的92例单节段退行性腰椎管狭窄症患者进行回顾性研究,手术全程给予SEP监测。随访时间15.6±1.8个月（12～23个月）。根据Lee等的腰椎管狭窄MRI分级将患者分为1级组（31例）、2级组（33例）和3级组（28例）。记录分析各组椎间隙处理前及融合器置入后的SEP波幅值;测量手术前、末次随访时责任间隙硬膜囊面积、椎间隙高度及椎间孔高度;临床疗效评价采用腰腿痛VAS评分和腰椎JOA评分。影像学结果及临床疗效改善率与SEP波幅改善率的相关性采用Pearson相关性分析。结果：3组椎间隙处理前与融合器置入后SEP平均波幅值的差异有统计学意义（P<0.05）;1级组、2级组和3级组SEP波幅平均改善率分别为（48.32±7.37）%、（112.34±18.67）%和（28.05±6.78）%,其中3级组有3例患者SEP波幅无任何变化。3组术后末次随访时的椎间隙高度、椎间孔高度、硬膜囊面积及腰腿痛VAS评分和腰椎JOA评分均较术前明显改善,差异有统计学意义（P<0.05）;2级组末次随访时椎间隙高度、椎间孔高度、硬膜囊面积改变值大于1级组和3级组,差异有统计学意义（P<0.05）;3组之间末次随访时腰腿痛VAS评分和腰椎JOA评分改变值差异有统计学意义（P<0.05）。末次随访时,1级组、2级组和3级组腰椎JOA评分改善率分别为（87.0±36.2）%、（85.8±35.3）%和（46.1±26.2）%,优良率分别为93.5%（29/31）、84.8%（28/33）和50%（14/28）。1级组和2级组SEP波幅改善率与末次随访时硬膜囊面积、椎间隙高度、椎间孔高度、腰腿痛VAS评分和腰椎JOA评分的改善率呈正相关;3级组SEP波幅改善率与末次随访时硬膜囊面积、腿痛VAS评分和腰椎JOA评分的改善率呈弱相关。1级组优良病例SEP改善率均大于25.6%,2级组优良病例SEP波幅改善率均大于85.3%。结论：OLIF治疗1、2级腰椎管狭窄症术中SEP波幅改善率可以作为判断间接减压是否有效的参考指标,对于手术中判断腰椎管狭窄间接减压的程度具有一定的参考意义。     

皮层体感诱发电位信号改善对脊髓型颈椎病手术预后的评价

[目的]研究皮层体感诱发电位(cortical somatosensory evoked potential,CSEP)在脊髓型颈椎病(cervicalspondylotic myelopathy,CSM)手术后出现信号改善(潜伏期缩短,或/和波幅增高)与临床症状恢复的相关性。[方法]对2008年7月～2010年5月本院收治的58例CSM患者,行术前、术中及术后CSEP监护并记录CSEP值,根据脊髓监护手术前后CSEP是否改善分为两组:波形改善组(A组),表现为波幅升高(>50%),或(和)潜伏期缩短(<5%);波形无改善组(B组)。于颈椎手术术前、术后1周和6个月分别行JOA评分(Japanese Orthopaedic As-sociation scoring system)评价神经功能,观察CSEP变化与神经功能恢复之间的关系。[结果]58例患者中36例(62.1%)CSEP出现改善;A组JOA评分术前、术后1周及术后6个月分别为8.42±1.06,14.71±1.31,15.43±1.26;B组分别为8.61±1.13,11.92±1.15,15.21±1.23。术后1周A组恢复高于B组(P<0.05...     

影响脊髓型颈椎病远期预后的相关因素分析

目的:探讨年龄、病程、MRI(脊髓受压程度、髓内信号)和皮层体感诱发电位(cortical somatosensory e-voked potential,CSEP)变化对脊髓型颈椎病(cervical spondylotic myelopathy,CSM)手术预后的影响。方法:选择颈前路减压植骨整合钛制带锁螺钉钢板固定治疗的28例CSM患者进行回顾性分析。年龄35～71岁,平均49.6岁;病程4个月～2年,平均18个月。分别依患者的年龄、病程、MRI(脊髓受压程度及有无信号异常)和CSEP等因素进行分组,根据日本矫形外科学会(JOA)制定的脊髓功能评分标准评价患者术后脊髓功能状态,分析各因素与脊髓型颈椎病手术预后的关系。结果:随访1.5～3年,平均2.3年。年龄>60岁与年龄≤60岁术后JOA评分差异有统计学意义(P<0.05),病程>6个月与病程≤6个月术后JOA评分差异有统计学意义(P<0.05),脊髓受压<1/3与脊髓受压≥1/3者术后JOA评分差异有统计学意义(P<0.05),MRIT2加权像和T1加权像信号正常者与T2加权像高信号者术后JOA评分差异有统计学意义(P<0.05),T2加权像高信号、T1加权像信号正常者与T2加权像高信号伴T1加权像信号减弱者术后JOA评分差异有统计学意义(P<0.01),CSEP正常者与异常者术后JOA评分差异无统计学意义(P>0.05)。结论:观察患者的年龄、病程、脊髓受压程度、髓内有无信号异常有助于预测CSM脊髓功能的预后,而不能仅依CSEP判断脊髓的功能状态。     

Charlson共病指数与单节段后路腰椎间融合手术预后的相关性分析

目的 探讨Charlson共病指数(Charlson comorbidity index, CCI)对单节段后路腰椎间融合手术临床疗效的预测价值。方法 选择2018年1月～2020年6月在我院接受单节段PLIF手术的357例患者资料进行回顾性分析,收集患者CCI指数、手术时间、术中出血量、JOA评分、JOA改善率、术后并发症、住院时间和住院费用等资料;根据CCI指数0分、1分、≥2分进行分组,观察患者临床资料差异。结果 357例患者根据CCI指数进行分组,0分组138例,1分组144例,≥2分组75例。≥2分组患者的住院时间、住院费用均显著高于0分组和1分组(P<0.05)。三组患者的手术时间、术中出血量和术后并发症差异均无统计学意义(P>0.05)。0分组的JOA改善率与≥2分组差异有统计学意义(P<0.05)。CCI指数与JOA改善率存在显著负相关(r=-0.301,P<0.05)。结论 CCI指数与单节段后路腰椎间融合手术预后存在一定相关性,CCI≥2分与患者JOA改善率降低、住院时间延长和住院费用增加相关。     

CSM患者术前磁共振DTI与术后神经功能康复的分析

目的 探讨脊髓型颈椎病(cervical spondylotic myelopathy,CSM)患者术前磁共振弥散张量成像(diffusion tensor imaging,DTI)量化参数与术后神经功能康复的关系.方法 选取2019年4月～2020年9月本院收治的CSM患者84例(CSM组),分为术后康复良好组59例和康复不佳组25例;同期选取无CSM病史的健康志愿者42例(健康对照组).分析两组术前的T1加权成像(T1 weighted imaging,T1 WI)、T2加权成像(T2 weighted imaging,T2 WI)及DTI成像影像学特征,比较两组的DTI量化参数[表观弥散系数(apparent dispersion coefficient,ADC)、各向异性系数(fractional anisotropy,FA)].术后功能康复采用JOA颈椎功能评分,计算其改善率.采用Pearson相关性分析评估术前ADC值、FA值与JOA评分的相关性.采用ROC曲线分析评估术前ADC值、FA值对CSM诊断及CSM术后功能康复不佳的预测价值.结果 CSM组术前ADC值显著高于健康对照组,FA值显著低于健康对照组(P<0.05).康复不佳组的术前ADC值显著高于康复良好组,FA值显著低于康复良好组(P<0.05).康复不佳组的术前JOA评分、术后JOA评分、JOA评分改善率均显著低于康复良好组(P<0.05).术前ADC值与术前JOA评分、术后JOA评分、JOA评分改善率均呈负相关(r=-0.467、-0.520、-0.572);术前FA值与术前JOA评分、术后JOA评分、JOA评分改善率均呈正相关(r=0.553、0.626、0.619).术前ADC值预测CSM术后功能康复不佳的灵敏度为80.00％,特异度为81.36％(AUC=0.828);术前FA值预测CSM术后功能康复不佳的灵敏度为80.00％,特异度为77.97％(AUC=0.819).结论 术前DTI量化参数ADC值、FA值与脊髓功能JOA评分存在关联,对诊断CSM以及评估术后功能康复效果有较好的预测价值.     

显微内窥镜下腰椎间盘突出症治疗

目的对比研究MED法与Love法治疗腰椎间盘突出症的临床效果. 方法 1999年12月以来手术治疗单一节段腰椎间盘突出70例,其中MED法与Love法各35例,比较手术前后JOA评分,术后改善率,手术切口长度,出血量,手术时间,髓核摘除量,术后发热,术后下地时间. 结果术前JOA评分MED组与Love组分别为12.2±1.8与12.1±1.4(t=0.437,p=0.663);术后JOA分别为26.9±1.6和26.1±5.3(t=1.80,p=0.077);改善率分别为87.8%和83.1%(t=1.84,p=0.069);手术切口长度分别为(2.0±0.1)cm和(5.0±0.6)cm(t=26.721,p＜0.001);出血量分别为(41±12)ml和(69±15)ml(t=11.167,p＜0.001);手术时间分别为(69±15)分钟和(56±9)分钟(t=4.057,p＜0.001);最高体温分别为(36.8±0.1)℃和(37.5±0.3)℃(t=10.80,p＜0.001);髓核摘除量分别为(1.6±0.4)g和(2.2±0.4)g(t=8.40,p＜0.001);术后下地时间分别为(1±0.5)天和(2.5±0.5)天(t=11.95,p＜0.001). 结论 MED组与Love组均取得了满意的效果,MED手术具有创伤小,恢复快.     

颈椎前路显微手术减压治疗脊髓型颈椎病临床疗效

目的 评价颈椎前路显微手术减压治疗脊髓型颈椎病安全性与有效性.方法 应用显微手术进行减压、植骨与内固定治疗.术中监测皮层体感诱发电位(CSEP)与运动诱发电位(MEP)改变及术后有无神经功能丢失.术后观察MRI图像,判断椎管减压的彻底性;根据手术前后MRI图像,测量并比较椎管与脊髓最狭窄处前后径与面积;神经功能JOA评分评价手术疗效.结果 临床治疗38例,2例减压过程出现CSEP一般预警,发生率为6%;无1例CSEP危险预警与MEP消失;术后无神经功能损害加重.32例术后获MRI检查,椎管内骨赘与突出的椎间盘均完全清除.椎管前后径术后增加58.95%;椎管面积增加48.12%;脊髓前后径术后增加33.68%;脊髓面积增加37.38%.JOA评分平均改善率为65.2%.结论 颈椎前路显微手术减压治疗脊髓型颈椎病安全性高、减压效果好.     

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.