动态牵引支架结合有限内固定与克氏针内固定治疗近指间关节Pilon骨折的病例对照研究

目的:比较动态牵引支架结合有限内固定与克氏针交叉内固定治疗近指间关节Pilon骨折的临床疗效及安全性。方法:自2012年6月至2014年6月,采用动态牵引支架结合有限内固定与克氏针交叉内固定两种手术方案治疗闭合近指间关节Pilon骨折41例45指,全部获得随访。动态牵引支架结合有限内固定组(A组)21例22指,男12例,女9例;平均年龄(30.6±5.6)岁。克氏针交叉内固定组(B组)20例23指,男11例,女9例;平均年龄(30.1±5.3)岁。定期复查X线片,评定关节主动活动范围、骨折愈合时间、感染率及术后关节活动疼痛等指标。结果:根据中华医学会手外科学会上肢部分功能评定试用标准评定,A组功能评定优良19例,B组13例,A组优于B组(Z=2.558,P=0.011).骨折平均愈合时间 A组(7.9±2.1)周,B组(8.1±2.3)周,两组差异无统计学意义(t=-0.304,P=0.762).A组感染5指,B组1指,A组感染率高于B组(χ²=3.287,P<0.05).术后关节活动疼痛VAS评分A组0.18±0.50,B组0.65±0.88,A组关节疼痛低于B组(t=-2.207,P<0.05).结论:动态牵引支架结合有限内固定治疗近指间关节Pilon骨折方法可靠,能有效固定骨折,进行早期功能锻炼,恢复关节功能。     

脊柱侧凸数字导航模板的准确性与安全性的病例对照研究

目的:设计新型脊柱侧凸个体化数字导航模板(简称导板)并在手术中应用,评价其置钉准确性和安全性。方法:2013年12月至2014年12月,对10例脊柱侧凸病例(观察组)进行CT扫描,应用计算机软件进行模型重建、模拟置钉和导板设计;应用快速成型技术制造导板;在手术中应用导板辅助置钉,记录其出血量、手术时间、术前与术后血肌酐含量变化、置钉相关并发症发生情况,术后CT扫描明确螺钉位置并进行分级,评价置钉准确率,并与同期行徒手置钉的10例脊柱侧凸病例(对照组)进行对比。观察组包括特发性侧凸5例,先天性侧凸5例;男3例,女7例;年龄4～18岁,平均11.9岁;主弯Cobb角42.1°～78.4°,平均54.9°。对照组包括特发性侧凸5例,先天性侧凸5例,男2例,女8例;年龄6～17岁,平均12.6岁;主弯Cobb角38.2°～93.4°,平均56.6°。结果:观察组置钉167枚,其中Ⅰ级138枚(82.6%),Ⅱ级25枚(15.0%),Ⅲ级4枚(2.4%),无Ⅳ级螺钉;穿破皮质29枚(17.4%),可接受螺钉163枚(97.6%).对照组置钉165枚,其中Ⅰ级98枚(59.4%),Ⅱ级39枚(23.6%),Ⅲ级21枚(12.7%),Ⅳ级7枚(4.2%);穿破皮质67枚(40.6%),可接受螺钉137枚(83.0%).两组病例置钉分级、穿破皮质比例、可接受螺钉比例均有差异(Z=-5.013,P=0.000;χ²=9.347,P=0.002;χ²=20.242,P=0.000).Cobb角矫正率[(74.1±10.0)% vs (69.7±17.6)%,出血量(455±447) ml vs (415±389) ml,手术时间 (163.5±53.7) min vs(164.0±48.7) min,术前与术后3 d血Cr变化(-5.3±3.2) vs (-3.4±3.1) μmol/L,差异均无统计学意义(t=0.696,P=0.496;t=0.214,P=0.833;t=0.022,P=0.983;t=1.375,P=0.192).两组均未见与置钉相关的并发症。结论:应用个体化数字导航模板辅助脊柱侧凸术中椎弓根螺钉置入,准确性较徒手置钉明显提高,且安全性良好。     

儿童肱骨髁上骨折保守治疗旋前或旋后固定后肘内翻畸形的病例对照研究

目的: 通过回顾性分析比较手法复位后旋前或旋后位石膏固定的儿童肱骨髁上骨折肘内翻畸形发生情况,从而指导临床治疗.方法: 收集2009年6月至2011年12月在我院急诊骨科行手法复位石膏固定的儿童肱骨髁上骨折病例,经筛选排除后共64例.按手法复位后固定位置不同分为两组：A组采用手法复位并旋前位石膏固定,B组采用手法复位并旋后位石膏固定.A组30例,男18 例,女12例;平均年龄(7.5±3.5) 岁;B组34例,男23 例,女11 例,平均年龄(7.0±2.6)岁.比较两组组间及组内的肘内翻发生率及提携角减小角度.结果: A组出现13例肘内翻,B组出现16例,两组差异无统计学意义(χ²=0.089,P=0.765).A组提携角减小角度(8±4)°,B组提携角减小角度(9±5)°,两组差异无统计学意义(t=0.584,P=0.564).A组组内桡偏型与尺偏型的肘内翻发生率与提携角减小角度差异均有统计学意义(χ²=6.160,P=0.013;t=-2.409,P=0.035);B组组内桡偏型与尺偏型的肘内翻发生率与提携角减小角度差异均有统计学意义(χ²=5.120,P=0.024;t=-2.250,P=0.041).两组肘关节功能Flynn评价差异无统计学意义(P=0.822).结论: 儿童肱骨髁上骨折旋前位固定和旋后位固定肘内翻发生率和提携角减小角度均无明显差异.而尺偏型儿童肱骨髁上骨折,旋前位固定有利于降低肘内翻率及其程度;桡偏型儿童肱骨髁上骨折,旋后位固定有利于降低肘内翻率及其程度.     

前交叉韧带重建术中界面螺钉在股骨侧的改良应用

目的：比较股骨侧袢钢板固定和界面螺钉由股骨侧进钉固定前交叉韧带股骨端的临床疗效。方法：回顾性分析2019年1至2021年9月行关节镜下前交叉韧带重建患者65例,按其股骨侧固定方式不同分为袢钢板组和界面钉组。袢钢板组(袢钢板固定)35例,男27例,女8例,年龄18~50(35.00±7.60)岁。界面钉组(界面钉固定)30例,男20例,女10例,年龄18~50(32.00±8.50)岁。比较两组患者住院时间、住院费用、手术时间、术中并发症,术后1、3、6 d的C反应蛋白及术后18个月Lysholm评分和国际膝关节文献委员会(International Knee Documentation Committee,IKDC)评分和CT测量的股骨隧道直径扩大值。结果：所有患者成功接受手术,并获得随访,时间18~36(25.16±4.50)个月。所有患者前抽屉试验和Lachman试验均转为阴性。两组患者住院时间、住院费用、并发症比较,差异无统计学意义(P>0.05);袢钢板组手术时间(74.00±6.84) min与界面钉组(91.67±6.34) min比较,差异有统计学意义(P<0.05);术后1、3 d袢钢板组C反应蛋白分别为(40.00±10.10)、(20.00±8.23) mg·L^-1,界面钉组分别为(60.00±8.93)、(30±8.66) mg·L^-1,两组比较差异有统计学意义(P<0.05);术后6 d两组C反应蛋白比较,差异无统计学意义(P>0.05)。术后18个月,Lysholm评分、IKDC评分比较,差异无统计学意义(P>0.05)。袢钢板组CT冠状位和矢状位股骨隧道直径扩大值分别为(2.75±0.19) mm、(1.55±0.25) mm,界面钉组分别为(2.81±0.22) mm、(1.61±0.20) mm,两组比较差异有统计学意义(P<0.05)。结论：采用界面螺钉由关节外向内中央挤压固定肌腱,虽然手术步骤较为繁琐、手术时间略长,早期术后炎症反应略重,但骨隧道扩大却明显小于袢钢板悬吊固定,同时术后无金属异物残留,且临床效果与袢钢板悬吊固定无差异,仍然不失为一种良好的选择。     

iGuide虚拟导航辅助C臂CT引导下125I粒子植入术治疗溶骨性骨转移癌所致疼痛

目的 观察iGuide虚拟导航辅助C臂CT引导下经皮穿刺¹²⁵I粒子植入术治疗溶骨性骨转移癌所致疼痛的效果。方法 回顾性分析86例115处溶骨性骨转移癌引发疼痛患者,经常规治疗后疼痛无缓解或拒绝常规治疗,接受iGuide虚拟导航辅助C臂CT引导下经皮穿刺¹²⁵I粒子植入术。记录技术成功率、手术并发症、90%体积肿瘤吸收剂量（D90）,比较术前及术后1、4、8周患者每日吗啡摄入量（DMC）和视觉模拟量表（VAS）评分,以及术前与术后8周Karnofsky评分。结果 ¹²⁵I粒子植入术技术成功率100%;D90为93.56~142.46 Gy,平均（110.54±3.41） Gy。术前DMC及VAS评分分别为（86.28±22.18） mg及（6.40±0.96）分,术后1周降至（54.88±12.05） mg及（4.48±0.76）分,之后逐渐下降,至术后8周降为（23.14±7.07） mg及（1.86±0.65）分（P均<0.05）;Karnofsky评分由术前的（74.19±7.27）分升高至术后8周（88.37±6.66）分（P<0.05）。主要和次要并发症发生率分别为2.33%（2/86）和11.63%（10/86）。结论 iGuide虚拟导航辅助C臂CT引导下经皮穿刺¹²⁵I粒子植入术可有效缓解溶骨性骨转移癌所致疼痛,且安全性高。     

Rotarex经皮机械血栓切除术与开放取栓治疗急性下肢动脉血栓形成

目的 对比Rotarex经皮机械血栓切除术(PMT)与开放取栓治疗急性下肢动脉血栓形成的效果。方法 回顾性分析32例接受Rotarex PMT(PMT组)及45例接受经股动脉切开取栓(开放组)治疗的急性单侧下肢动脉血栓患者,对比组间球囊使用率及支架植入率,治疗相关并发症发生率、踝肱指数(ABI)变化、疼痛缓解及血管恢复通畅情况,以及截肢率及死亡率。结果 对全部患者均成功完成治疗。PMT组球囊使用率及支架植入率均高于开放组(P均＜0.05)。组间治疗相关并发症发生率差异无统计学意义[3.13%(1/32) vs. 13.33%(6/45),χ²=2.358,P=0.229]。治疗前组间ABI差异无统计学意义(P＞0.05),治疗后3天PMT组ABI低于开放组[(0.77±0.01) vs. (0.84±0.17),P=0.013],治疗后1个月PMT组ABI高于开放组[ (0.80±0.15) vs. (0.72±0.12),P=0.010]。治疗后1个月,PMT组疼痛改善率为90.63%(29/32),高于开放组[77.78%(35/45),P=0.033]。治疗后1、3、6及12个月,组间血管通畅率差异均无统计学意义(P均＞0.05)。治疗后12个月,PMT组截肢率及死亡率[9.38%(3/32)、3.13%(1/32)]与开放组[8.89%(4/45)、4.44%(2/45)]差异均无统计学意义(P均＞0.05)。结论 Rotarex PMT治疗急性下肢动脉血栓与开放取栓效果相当,且更利于缓解症状。     

C形臂X线定位下多次小直径钻孔联合体外冲击波疗法治疗早期股骨头坏死的疗效观察

目的:探究C形臂X线定位下多次小直径钻孔联合体外冲击波疗法(extracorporeal shock wave therapy,ESWT)对早期股骨头坏死(osteonecrosis of the femoral head,ONFH)的临床疗效。方法:回顾分析2015年5月至2017年5月收治的早期ONFH患者106例,其中53例采用C形臂X线定位下多次小直径钻孔联合ESWT治疗作为观察组,男41例,女12例,年龄22~70(45.85±6.01)岁;另外53例仅采用ESWT治疗作为对照组,男34例,女19例,年龄20~68(45.12±5.83)岁。观察比较两组患者治疗前后髋关节屈曲范围、外展内收活动范围、ONFH面积比例,比较两组治疗前后改良Harris评分(modified Harris hip scores,mHHS),视觉模拟评分(visual analog scale,VAS)。采用Kaplan-Meier法绘制生存曲线,比较两组患者治疗后3年随访期间的股骨头生存率。结果:患者均无创口愈合不良及感染等并发症的发生。106例患者均获得随访,时间28~36(31.06±4.28)个月。观察组mHHS总分、髋关节屈曲范围、髋关节外展内收活动范围由治疗前(63.85±5.42)分、(23.79±2.21)°、(32.40±4.19)°分别增加至治疗后2年的(85.51±5.69)分、(34.65±2.73)°、(43.32±5.71)°(P<0.05);对照组分别由治疗前的(64.73±5.64)分、(23.82±2.18)°、(32.45±4.13)°增加至治疗后2年的(81.65±5.48)分、(32.79±2.87)°、(39.75±5.68)°(P<0.05)。观察组VAS、ONFH面积比例分别由治疗前的(5.76±1.41)分、(35.07±4.96)%降低至治疗后2年的(3.39±1.02)分、(22.04±3.23)%(P<0.05),对照组分别由治疗前的(5.73±1.45)分、(35.24±5.18)%降低至治疗后2年的(4.43±1.21)分、(28.32±3.76)%(P<0.05);治疗后两组间各项指标比较,差异均有统计学意义(P<0.05)。观察组患者治疗后3年的股骨头生存率明显高于对照组(P<0.05)。结论:C形臂X线定位下多次小直径钻孔联合ESWT治疗早期ONFH能够明显改善患者的临床症状,缓解疼痛,提高临床疗效。     

原发性中枢神经系统淋巴瘤Toll样受体4表达水平与弥散加权成像表观弥散系数值的相关性

目的 观察原发性中枢神经系统淋巴瘤(PCNSL)Toll样受体4(TLR4)表达水平与MR弥散加权成像(DWI)表观弥散系数(ADC)值的相关性。方法 回顾性分析17例经病理确诊的PCNSL患者,观察病灶ADC值、TLR4及NF-κB表达水平之间的相关性。结果 PCNSL病灶ADC值为460×10^－6~1 034×10^－6 mm²/s,平均(756±147)×10^－6 mm²/s;TLR4表达水平为0.02~0.11,平均0.06±0.03,NF-κB表达水平为0.04~0.15,平均0.08±0.03。TLR4表达水平与ADC值呈负相关(r=－0.76,P<0.01);NF-κB表达水平与TLR4及ADC值之间无明显相关性(P均>0.05)。结论 PCNSL的TLR4表达水平与其ADC值呈负相关。     

肝细胞癌伴严重门静脉高压并发症行TIPS治疗的安全性

目的 观察TIPS治疗巴塞罗那临床肝癌(BCLC)D期肝细胞癌(HCC)伴严重门静脉高压并发症的安全性。方法 纳入24例BCLC D期HCC伴严重门静脉高压并发症患者,观察TIPS及其后随访资料,分析TIPS技术成功率、门静脉压力梯度(PPG)变化、门静脉高压并发症缓解率、BCLD情况、并发症及死亡率等,评估其疗效。结果 TIPS技术成功率100%。TIPS前、后PPG分别为(32.13±6.93)mmHg及(18.75±5.05)mmHg,TIPS后PPG降低(t=12.604,P＜0.001)。TIPS 后次日,1例因支架内癌栓及血栓致支架急性闭塞,予补充性植入1枚覆膜支架后血流恢复;TIPS 后2周门静脉高压并发症缓解率100%,未见相关并发症及死亡。TIPS前及1个月后患者体力状况(PS)评分分别为3.08±0.28及1.97±1.01;肝功能Child-Pugh评分分别为7.50±1.79及5.71±2.22,差异均有统计学意义(t=6.273、5.033,P均＜0.001)。TIPS 后1个月,HCC BCLC C期15例、B期4例、A期3例,与TIPS前差异有统计学意义(χ²=13.565,P＜0.001);2例死于多器官功能衰竭。TIPS 后3个月2例发生Ⅲ级肝性脑病,均经对症处理后缓解;支架分流道通畅率及门静脉高压并发症缓解率均为100%。结论 TIPS治疗BCLC D期HCC伴严重门静脉高压并发症安全、有效。     

C臂CT辅助数字减影血管造影引导肾上腺静脉取血

目的 观察C臂CT辅助数字减影血管造影(DSA)引导肾上腺静脉取血(AVS)的价值。方法 回顾性分析57例原发性醛固酮增多症(PA)患者,其中25例接受DSA引导AVS(DSA-AVS组)、32例接受C臂CT辅助DSA引导AVS(C臂CT-AVS组),比较组间插管总成功率(双侧AVS均插管取血成功为总成功)、曝光时间及辐射剂量面积乘积(DAP)。结果 C臂CT-AVS组AVS插管总成功率为84.38%(27/32),DSA-AVS组为52.00%(13/25),组间差异有统计学意义(χ²=7.00,P=0.01);组间曝光时间及DAP差异均无统计学意义(P均＞0.05)。DSA-AVS组1例右肾上腺静脉(RAV)破裂出血,出血较少,后自行缓解;2组均未见肾上腺危象、严重出血、下腔静脉穿孔等严重并发症。结论 C臂CT辅助DSA引导可在不增加曝光时间和辐射剂量的前提下提高AVS技术成功率。     

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.