关节镜手术联合富血小板血浆治疗半月板损伤的Meta分析

目的：探讨关节镜手术联合富血小板血浆（platelet-rich plasma,PRP）治疗半月板损伤的临床疗效。方法：计算机检索PubMed、Science Direct、Cochrane library、中国期刊全文数据库、万方数据库和维普数据库中关节镜手术联合PRP与单纯关节镜手术修复半月板损伤的临床对照研究,检索时间自2015年1月至2019年12月。根据纳入和排除标准,进行文献筛查、数据提取并评价其方法学质量。采用RevMan 5.3软件比较两种治疗方式术后1,6,12个月的膝关节疼痛视觉模拟评分（visual analogue scale,VAS）,Lysholm评分和术后3,6,12个月西安大略和麦克马斯特大学骨关节炎指数（Western Ontario and McMaster University Osteoarthritis Index,WOMAC）。结果：共纳入9项研究,329例半月板损伤患者,关节镜手术联合PRP组146例,单纯关节镜手术组183例。两组术后1、6、12个月VAS评分比较差异无统计学意义（P>0.05）。两组术后1,6个月Lysholm评分[MD=3.85,95% CI （1.25,6.44）,P<0.05],[MD=2.88,95% CI （0.13,5.63）,P<0.05]比较差异有统计学意义;术后12个月Lysholm评分比较差异无统计学意义[MD=5.88,95% CI （-8.72,20.48）,P=0.43]。两组术后3、6个月WOMAC比较差异有统计学意义[MD=-8.07,95% CI （-11.17,-4.89）,P<0.000 01],[MD=-7.96,95% CI （-11.44,-4.48）,P<0.000 01];但术后12个月WOMAC评分比较差异无统计学意义[MD=-6.61,95% CI （-16.64,3.41）,P>0.05]。结论：关节镜手术联合PRP修复半月板损伤在改善膝关节功能,延缓关节炎方面短期疗效优于单纯关节镜手术,但两者长期疗效及缓解疼痛方面疗效相当。     

关节镜手术治疗对早期膝骨关节炎的中期临床疗效

目的：比较关节镜手术治疗与保守治疗对中老年人早期膝关节骨关节炎（early knee osteoarthritis,EKOA）的中期临床疗效,为中老年EKOA的个体化治疗提供临床依据。方法：回顾性纳入2015年1月至2016年12月行关节镜手术治疗或保守治疗的145例（182膝）中老年EKOA患者,其中男35例、女110例,年龄47~79（57.6±6.9）岁,病程6~48（14.6±8.9）个月。根据治疗方式分为关节镜治疗组（47例,58膝）和保守治疗组（98例,124膝）。治疗前患者主要临床症状包括膝关节疼痛、肿胀、交锁、屈伸受限及膝关节无力等,膝关节X线主要表现为关节间隙无狭窄或可疑狭窄、少量骨赘形成,膝关节MRI主要表现为关节软骨和半月板退变或损伤、关节内游离体及滑膜充血水肿等。收集两组患者治疗前的膝关节症状持续时间、半月板是否合并损伤、是否合并关节内游离体、是否存在膝关节交锁等机械性症状,以及治疗前和治疗后的疼痛视觉模拟评分（visual analogue scale,VAS）和Lysholm膝关节功能评分。统计分析组内和组间治疗前后VAS和Lysholm评分差异。结果：两组患者均获随访,时间60~76个月;关节镜手术组患者切口愈合良好,未发生手术并发症。两组间的年龄、性别、身体质量指数（body mass index,BMI）及随访时间差异无统计学意义（P>0.05）。治疗前,关节镜治疗组与保守治疗组相比,关节镜治疗组的症状持续时间更长（P<0.001）,合并半月板损伤（P<0.001）、游离体（P=0.001）及机械性症状（P<0.001）的比例更高,VAS评分（P<0.001）及Lysholm评分（P<0.001）更差。治疗后末次随访时,各组VAS评分、Lysholm评分均较治疗前明显改善（P<0.05）。末次随访时,VAS评分,关节镜治疗组（1.5±1.2）分,保守治疗组（1.6±1.0）分（P=0.549）;Lysholm评分,关节镜治疗组（84.9±12.5）分,保守治疗组（84.2±9.9）分（P=0.676）。结论：对中老年EKOA患者,关节镜手术治疗与保守治疗均具有较满意的中期临床疗效。尽管两组末次随访时疗效差异无统计学意义,但关节镜手术治疗组术前症状较重,多合并半月板损伤或游离体所导致的机械性交锁症状,故对于合并机械性交锁症状或保守治疗效果较差的中老年EKOA患者可考虑关节镜手术治疗。     

影响症状性外侧盘状半月板术后疗效的相关危险因素分析

目的：探讨关节镜治疗症状性外侧盘状半月板（discoid lateral meniscus,DLM）术后疗效的影响因素。方法：回顾性分析2008年9月至2015年9月于四川大学华西医院运动医学中心诊断为症状性DLM并行关节镜手术治疗的患者。膝关节功能由Lysholm评分系统进行评估,根据评分结果分为优（≥ 90分）、良（80~89分）、可（70~79分）、差（<70分）。收集患者临床资料,包括性别、手术年龄、体质量指数、工作强度、症状持续时间、膝关节创伤史、受累膝关节侧别、DLM分型、DLM损伤类型、DLM损伤部位、内侧半月板损伤、膝关节软骨损伤部位及损伤程度、Kellgren-Lawrence （K-L）分级、手术方式、末次随访时间共16项拟研究因素。根据数据类型,单因素分析采用Kruskall-Wallis秩和检验或χ²检验,多因素分析采用有序Logistic回归模型。单因素分析具有统计学意义的因素纳入多因素分析模型,最终获得影响症状性DLM术后疗效的独立危险因素。结果：根据纳入排除标准,共纳入502例患者。末次随访的Lysholm功能分级高于术前（P<0.001）。单因素分析显示：在Lysholm各功能分级之间,性别、体质量指数、工作强度、膝关节创伤史、手术年龄、症状持续时间、内侧半月板损伤、K-L分级、手术方式、膝关节软骨损伤部位及程度的差异均有统计学意义（P<0.05）。有序Logistic回归分析显示：女性是影响术后疗效的独立危险因素（P=0.002,OR=0.370）;体质量指数（P=0.007,OR=0.894）,工作强度（P=0.004,OR=0.525）,手术年龄（P<0.001,OR=0.953）,症状持续时间（P<0.001,OR=0.989）,膝关节软骨损伤程度（P=0.016,OR=0.631）与Lysholm膝关节功能分级呈负相关。结论：关节镜是治疗症状性DLM安全、有效的方法,性别、体质量指数、工作强度、手术年龄、症状持续时间以及膝关节软骨损伤程度是症状性DLM术后疗效的独立影响因素。     

射频治疗对关节镜下半月板部分切除术早期疗效的影响

目的 探讨半月板部分切除术后使用射频汽化修整残留半月板对病人术后膝关节预后的影响。方法 前瞻性地纳入60例病人,随机分为两组,观察组（26例）病人采用膝关节镜下半月板部分切除+射频修整术,对照组病人（34例）采用膝关节镜下单纯半月板部分切除术。对比两组病人术后48 h伤口引流量及疼痛视觉模拟量表（visual analogue scale, VAS）评分;采用膝关节Lysholm评分标准评估膝关节功能,记录并比较两组病人术前及术后6个月随访时的Lysholm评分。结果 观察组和对照组病人的术后引流量分别为（51.15±22.69） ml、（63.24±23.45） ml,VAS评分分别为（1.45±0.50）分、（1.62±0.55）分,两组间比较,差异均无统计学意义（t=0.264,P=0.610;t=0.259,P=0.613）;所有入组病人术后的Lysholm评分为（91.58±5.78）分,均优于术前的（73.53±4.52）分,差异有统计学意义（t=8.012,P=0.005）;观察组及对照组术后的Lysholm评分分别为（90.00±5.54）分、（92.79±5.75）分,差异无统计学意义（t=0.219,P=0.641）。结论 关节镜下行半月板部分切除术的出血量与使用射频汽化仪无关,无论是否使用射频汽化修整残留半月板,病人术后膝关节的功能都能得到较好的恢复。     

加速康复外科在关节镜下半月板损伤修复围术期护理中的应用

目的 探讨加速康复外科（enhanced recovery after surgery, ERAS）优化方案在关节镜下半月板损伤修复围术期护理的应用效果。方法 选取2017年1月至6月在北京积水潭医院运动医学科收治的膝关节半月板损伤病人90例,按照随机数字表法分为ERAS组和常规组,每组45例。ERAS组围术期在常规护理方法的基础上,给予改进的ERAS优化护理方案。比较两组病人术后疼痛视觉模拟量表（visual analogue score, VAS）评分、膝关节活动度恢复时间、Lysholm膝关节评分（Lysholm knee score scale, LKSS）、住院时间和费用、术后并发症及术后满意度情况。结果 两组病人术前至术后48 h各时间点的VAS评分均呈下降趋势（F_ERAS组=14.355,F_常规组=5.728,P均＜0.05）,从各个时间点看,ERAS组的VAS评分值显著低于常规组（F_组间=11.937,P_组间=0.001）,不同时间点与分组之间存在交互作用（F_交互=16.571,P_交互＜0.001）;ERAS组术后膝关节活动度恢复至30°、60°、90°及120°时间明显早于常规组（P＜0.001）,且病人住院时间短（t=-5.181,P＜0.001）、住院费用低（t=-3.263,P=0.002）、术后Lysholm膝关节评分更佳（t=10.682,P＜0.001）;ERAS组病人术后恶心、呕吐、尿潴留、关节积液等并发症发生率较常规组低（P＜0.05）,总体满意度明显高于常规组（Z=-2.455,P=0.014）。结论 ERAS优化方案应用于关节镜下半月板损伤修复的围术期护理中效果显著,可明显降低病人术后疼痛程度,缩短住院时间,减少住院总费用和并发症发生率,有效改善病人早期及远期膝关节活动情况,提高病人治疗综合满意度。     

3D弥散法MR膝关节造影对半月板损伤诊断价值的探讨

目的:探讨3D弥散法MR膝关节造影诊断半月板撕裂的临床应用价值。方法: 收集自2013年1月至2014年1月的42例临床怀疑半月板撕裂的患者,其中男31例,女11例;年龄21～67岁,平均38.4岁;病程2 h～15 d;临床症状是膝关节痛。首先采用膝关节常规MR平扫,然后进行3D弥散法MR膝关节造影检查,全部病例经关节镜或手术证实,将常规平扫结果和3D弥散法关节造影诊断结果与关节镜或手术结果对照,对比两种方法在显示半月板撕裂图像敏感性和特异性方面的差异。结果:3D弥散法MR膝关节造影使半月板撕裂处信号强度明显高于常规平扫,同时检查的敏感性从52.94%(54/102)提高到85.79%(87/102),特异性从67.78%(61/90)提高到86.67%(78/90).对两种方法进行χ²检验,敏感性及特异性之间差异有统计学意义(χ²=25.90,P<0.01; χ²=9.13,P<0.01).结论:3D弥散法膝关节造影对半月板撕裂图像敏感性及特异性均优于常规MR平扫。     

关节镜下缝合术治疗半月板前角损伤的疗效

目的:探讨关节镜下使用MenderⅡ缝合器修复半月板损伤的临床疗效。方法:半月板前角损伤47例,其中男29例(29膝),女18例(18膝);年龄12～31岁,平均(20.53±4.12)岁;病程3～35 d,平均(12.43±5.74) d.应用MenderⅡ缝合器在膝关节镜下行由外向内缝合术,并对患者术前、术后疼痛、跛行等采用Lysholm膝关节评分系统进行评估分析。结果:46例均获随访,时间12～48个月,平均(31.84±8.34)个月。所有患者手术切口Ⅰ期愈合,未出现重要血管、神经损伤等并发症,患膝关节交锁症状均消失,其疼痛、跛行、肿胀、活动受限等症状明显好转,Lysholm膝关节评分由术前52.33±7.31提高至术后86.74±6.92.结论:应用MenderⅡ缝合器对半月板前角损伤患者行由外向内缝合术,术后症状改善明显,近期疗效满意。     

高能量激光疗法联合本体感觉训练对半月板损伤病人术后膝关节疼痛及运动功能的疗效

目的 探讨高能量激光疗法（HILT）联合本体感觉训练对半月板损伤病人术后膝关节疼痛和功能的疗效。方法 选取2021年1月至2023年1月我院收治拟行关节镜半月板成形术的膝关节半月板损伤病人82例,采用随机数字表法分为观察组和对照组,每组41例。两组病人术后康复训练2周后,对照组采用本体感觉训练,观察组采用HILT联合本体感觉训练。观察两组治疗前后疼痛视觉模拟量表（VAS）评分,简版生活质量量表（SF-12）评分,美国膝关节协会（AKS）评分,膝关节主动活动度和下肢运动学指标（步频、步长、步速）,并发症发生率和病人满意度。结果 治疗10周后,两组VAS评分均较治疗前显著降低（P均＜0.05）,SF-12评分、AKS的膝关节评分和活动功能评分、膝关节屈曲和伸展角度以及下肢运动学指标均较治疗前显著提升（P均＜0.05）;观察组VAS评分显著低于对照组（P＜0.05）,SF-12评分、膝关节评分和活动功能评分、膝关节屈曲和伸展角度以及下肢运动学指标均显著高于对照组（P＜0.05）。结论 HILT联合本体感觉训练能够有效改善半月板损伤病人术后膝关节疼痛、运动功能和生活质量,并且还能够减少术后并发症、提高治疗满意度。     

多层螺旋CT与MRI在膝关节隐匿性骨折伴半月板及韧带损伤中的诊断比较

目的:探讨多层螺旋CT(multislice spiral CT,MSCT)和MRI对膝关节隐匿性骨折伴半月板及韧带损伤的诊断价值。方法:自2020年1月至2021年3月,经关节镜或手术定性确诊膝关节隐匿性骨折伴半月板及韧带损伤患者63例,男41例,女22例,年龄21~67(44.35±8.77)岁,病程1~6(4.64±1.75) d;体质量指数(body mass index,BMI)(19.85±2.78) kg/m²。收集63例患者的MSCT和MRI检查资料,统计分析相关数据并评价二者的诊断价值。结果:MRI对膝关节隐匿性骨折伴半月板及韧带损伤、关节腔积液、骨髓水肿和关节面损伤的检出率分别为100.00%(63/63),95.24%(60/63),42.86%(27/63)和36.51%(23/63),MSCT的检出率分别为49.21%(31/63),41.27%(26/63),0.00%(0/63)和1.59%(1/63),差异有统计学意义(P<0.05);MRI的诊断灵敏度、特异度和准确度高于MSCT(P<0.05)。结论:MRI对膝关节隐匿性骨折伴半月板及韧带损伤的诊断灵敏度、特异度和准确度明显优于多层螺旋CT,对关节腔、关节面及骨髓等周围组织病变诊断准确性较高,可降低临床误诊风险。     

关节镜下单通道双线技术治疗胫骨髁间棘骨折

目的:探讨关节镜下单通道双线技术治疗胫骨髁间棘骨折的临床疗效。方法:2016年1月至2020年4月,收治22例胫骨髁间棘骨折患者,男14例,女8例;年龄26~45(34.8±5.9)岁;手术时间为受伤后5~15(11.2±4.1) d。所有患者给予关节镜下骨块复位和单通道双线技术固定。术后根据X线片评估骨折愈合情况,术前及末次随访采用Lysholm评分、IKDC 2000评分和抽屉试验进行临床疗效评价。结果:22例患者全部获得随访,时间12~75(34.6±13.0)个月。Lysholm评分术前(30.80±9.55)分,末次随访(89.60±2.89)分,差异有统计学意义(t=9.67,P<0.01);IKDC 2000术前(24.60±7.21)分,末次随访(80.00±6.17)分,差异有统计学意义(t=11.41,P<0.01)。1例患者抽屉试验为弱阳性。结论:单通道双线技术可实现对髁间棘撕脱骨块的有效固定,操作简便、创伤小,适用于各种类型的髁间棘撕脱骨折。目的:探讨关节镜下单通道双线技术治疗胫骨髁间棘骨折的临床疗效。方法:2016年1月至2020年4月,收治22例胫骨髁间棘骨折患者,男14例,女8例;年龄26~45(34.8±5.9)岁;手术时间为受伤后5~15(11.2±4.1) d。所有患者给予关节镜下骨块复位和单通道双线技术固定。术后根据X线片评估骨折愈合情况,术前及末次随访采用Lysholm评分、IKDC 2000评分和抽屉试验进行临床疗效评价。结果:22例患者全部获得随访,时间12~75(34.6±13.0)个月。Lysholm评分术前(30.80±9.55)分,末次随访(89.60±2.89)分,差异有统计学意义(t=9.67,P<0.01);IKDC 2000术前(24.60±7.21)分,末次随访(80.00±6.17)分,差异有统计学意义(t=11.41,P<0.01)。1例患者抽屉试验为弱阳性。结论:单通道双线技术可实现对髁间棘撕脱骨块的有效固定,操作简便、创伤小,适用于各种类型的髁间棘撕脱骨折。     

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.