地舒单抗对绝经后骨质疏松性股骨颈骨折全髋关节置换术后股骨近端假体周围骨密度的影响

目的:研究地舒单抗对绝经后骨质疏松性股骨颈骨折患者全髋关节置换术后(total hip arthroplasty,THA)股骨近端假体周围骨密度的影响。方法:选取2020年10月至2021年10月绝经后女性骨质疏松性股骨颈骨折行THA术后54例,治疗组25例接受地舒单抗治疗,年龄(74.3±6.2)岁;对照组29例未接受地舒单抗治疗,年龄(75.2±4.8)岁。术后1周及3、6及12个月各个时间点,通过双能X线骨密度仪(DEXA型)测定股骨近端假体周围骨密度,并在不同时间点测量骨转换各项指标。结果:术后3、6及12个月对照组的抗酒石酸酸性磷酸酶(tartrate resistant acid phosphatase,TRACP-5b)高于治疗组(P<0.05);对照组术后12个月骨特异性碱性磷酸酶(bone-specific alkaline phosphatase,BALP)高于治疗组(P<0.05)。两组患者Gruen 1、7区的骨密度在术后3、6及12个月较术后1周(基线)均下降(P<0.05);对照组Gruen 7区术后各时间点比较,差异有统计学意义(P<0.05);治疗组各时间点比较,差异无统计学意义(P>0.05)。两组术后3个月Gruen 1、7区比较,差异无统计学意义(P>0.05);术后6个月Gruen 1、7区和术后12个月Gruen 1、7区,治疗组骨密度均明显高于对照组(P<0.05)。两组术后3个月Gruen 1、7区骨密度下降百分比比较,差异无统计学意义(P>0.05)。对照组术后6个月Gruen 1、7区,术后12个月Gruen 1、7区骨密度下降百分比明显高于治疗组(P<0.05)。提示在使用地舒单抗6个月后,即可降低骨密度丢失幅度,并且该效应可达至术后12个月。结论:绝经后骨质疏松性股骨颈骨折患者在THA术后,使用地舒单抗可减少股骨近端假体周围骨密度丢失,有效抑制骨吸收。     

老年人髋部骨折股骨近端骨质CT测量的意义

[目的]探讨老年人股骨近端松质骨CT值和皮质骨厚度值评估髋部骨折的意义。[方法]回顾性分析146例髋部CT检查患者,其中,73例髋部骨折,73例非髋部骨折。测量健侧股骨近端冠状位股骨头、股骨颈、转子间的松质骨CT值,以及股骨颈和转子间的皮质骨厚度值。[结果]骨折组股骨颈和转子间的CT值均显著低于非骨折组(P0.05),骨折组在股骨近端4个部位的皮质骨厚度值均显著低于非骨折组(P0.05)。ROC曲线下面积(area under curve, AUC)由大至小依次为:股骨颈外侧皮质厚度值转子间外侧皮质厚度值转子间CT值转子间内侧皮质厚度值股骨颈CT值股骨颈内侧皮质厚度值,P值均0.05。其中,股骨颈外侧皮质厚度及转子间外侧皮质骨厚度值的AUC分别为0.893及0.844。[结论]股骨颈和转子间的皮质骨厚度值及松质骨CT值可能具有预测骨质疏松髋部骨折的价值。     

高脂血症病人股骨颈骨折分型的临床研究

目的 探究高脂血症病人股骨颈骨折的分型特点。方法 将2012年8月至2017年11月在湖北省宜昌市第二人民医院骨外科和云南省中医医院骨科诊断为股骨近端骨折并符合纳入标准的196例病人作为研究对象,分为高血脂组（97例）和血脂正常组（99例）。根据股骨颈骨折部位及股骨转子间Evans骨折分型判断各例病人的骨折类型。入院及出院时分别检测各例病人的总胆固醇及低密度脂蛋白胆固醇（low density lipoprotein cholesterol, LDL-C）水平,将高血脂组按照高血脂病程分为短期组（≤1年）、中期组（＞1年,≤3年）和长期组（＞3年）。探究血脂水平与股骨颈骨折分型之间的潜在规律。结果 高血脂组股骨颈骨折者81例（83.5%）,显著高于血脂正常组的67例（67.7%）,差异有统计学意义（χ²=6.638,P=0.010）;长期组以颈中型骨折（19例,61.3%）最为多见,与短期组（1例,6.7%）、中期组（12例,23.5%）相比,差异有统计学意义（χ²=12.973,P=0.004;χ²=16.413,P均＜0.001）。高血脂组中,中、长期组血脂水平（总胆固醇、LDL-C）均高于短期组,差异均有统计学意义（P均＜0.05）。结论 合并长期（＞3年）高脂血症的股骨颈骨折病人中,以股骨颈颈中型骨折较为多见。     

股骨颈动力交叉螺钉系统与螺纹空心钉治疗垂直不稳定股骨颈骨折短期随访

目的：分析比较股骨颈动力交叉螺钉系统(femoral neck dynamic cross screw system,FNS)和螺纹空心钉(cannulated screws,CS)治疗垂直不稳定股骨颈骨折临床效果。方法：回顾分析2020年7月至2021年8月收治的40例垂直不稳定股骨颈骨折患者的临床数据和短期随访结果,根据不同的内固定治疗方法分为股骨颈动力交叉螺钉系统FNS组20例和螺纹空心钉CS组20例。FNS组中,男11例,女9例,年龄58.5(50.3,62.5)岁;CS组中,男9例,女11例,年龄52.0(40.5,58.0)岁。观察比较两组手术时间、手术刀口长度、手术中失血量、治疗费用。术后利用X线影像资料评价术后骨折愈合状况和手术内固定状况,并测量患侧股骨颈短缩状况。比较两组术后患侧大腿激惹症发生情况、术后部分负重以及完全负重时间、术后股骨头早期坏死、再次手术翻修情况以及Harris评分。结果：FNS组获随访18.0(15.0,19.0)个月,CS组随访17.0(15.0,18.8)个月。两组手术时间、手术切口长度、手术中失血量比较,差异均无统计学意义(P＞0.05)。FNS组的诊疗费用高于CS组(P＜0.001)。FNS组术后无患侧大腿激惹征,而CS组6例存在大腿外侧不适或大腿外激惹征(P＜0.05)。CS组术后平均部分负重活动时间和完全负重活动时间均长于FNS组(P＜0.05)。末次随访时,CS组术后患侧股骨颈短缩长度大于FNS组(P＜0.05)。两组均未发生术后股骨头早期坏死及再次手术翻修。两组术后12个月Harris评分比较,差异无统计学意义(P＞0.05)。结论：FNS治疗垂直不稳定股骨颈骨折可明显降低大腿外侧激惹征的发生率,并有效降低垂直不稳定股骨颈骨折术后短缩率,可提供较稳定的防旋力与抗切割力,使患者可以相对较早下地,有利于患者术后患侧髋关节功能恢复,是对于垂直不稳定股骨颈骨折手术治疗的一种全新选择,但由于治疗费用偏高,临床中因结合实际情况,选用恰当的手术治疗方式。     

股骨近端髓内钉微创治疗80岁以上高龄股骨粗隆间骨折

目的: 探讨股骨近端髓内钉(proximal femur intramedullary nail,PFNA)治疗高龄股骨粗隆间骨折的疗效. 方法: 对2008年1月至2010年12月收治的86例高龄(80～93岁)股骨粗隆间骨折患者的临床资料进行回顾性分析,其中采用闭合复位PFNA内固定治疗54例(PFNA组),男22例,女32例;采用传统开放复位钉板内固定术32例(对照组),男12例,女20例. 比较两组患者的手术时间、出血量、术后并发症、住院时间、骨折愈合时间及髋关节功能情况. 结果: 所有患者获得2年以上的随访,PFNA组的手术时间、出血量、术后并发症、住院时间均明显少于对照组(P<0.01);骨折愈合时间两组差异无统计学意义(P>0.05);髋关节功能Harris评分则明显优于对照组(P<0.01).结论: 应用PFNA治疗高龄患者股骨粗隆间骨折疗效优于传统手术.     

老年髋部骨折术后健侧骨折的危险因素分析

目的: 探讨老年髋部骨折术后健侧骨折的发生率及其相关危险因素为预防再次骨折提供依据。方法: 回顾分析2012年6月至2017年6月接受髋关节置换术或股骨近端髓内钉固定术治疗的65岁以上股骨颈骨折或转子间骨折452例患者的临床资料,男168例,女284例;年龄65~97(75.5±7.5)岁;股骨颈骨折191例,股骨转子间骨折261例;按照术后健侧髋部是否存在骨折,分为骨折组和无骨折组,记录两组患者性别、年龄、体质量指数、骨折类型、初次治疗方式、骨密度、医疗依从性、术后是否短期谵妄、伤前是否并存内科疾病及末次随访髋关节Harris评分。应用单因素Logostic回归分析筛选出术后健侧骨折的危险因素,再将有统计学意义的危险因素纳入多因素Logostic回归分析,筛选出老年髋部骨折术后健侧骨折的独立危险因素。结果: 452例患者中42例发生健侧髋部骨折,发生率为9.3%,两次骨折发生相隔时间平均(2.9±2.1)年。单因素Logistic回归分析结果示年龄、骨密度、医疗依从性、术后短期谵妄、伤前合并内科疾病及末次随访髋关节Harris评分差异均有统计学意义(P<0.05)。多因素Logistic分析显示年龄(OR=4.227)、骨密度(OR=4.313)、合并内科疾病(OR=5.616),以及末次随访髋关节Harris评分分级低(OR=3.891),是老年髋部骨折术后健侧骨折的独立危险因素(P<0.05)。结论: 年龄、骨密度、合并内科疾病以及末次随访髋关节Harris评分分级低是老年髋部骨折术后健侧骨折的主要危险因素,术后3年内要加强内科疾病的治疗,抗骨质疏松,改善髋关节功能,以预防健侧髋部骨折的发生。     

术中滑轨CT辅助在经皮骶髂关节螺钉治疗骨盆后环损伤中的应用

目的：比较术中滑轨CT联合C形臂X线机辅助与单纯使用C形臂X线机辅助透视下经皮骶髂关节螺钉治疗骨盆后环损伤临床疗效。方法：自2018年12月至2022年2月收治76例骨盆后环损伤患者,其中,C形臂联合滑轨CT辅助下行内固定治疗39例为CT组,男23例,女16例,年龄(44.98±7.33)岁;仅在C形臂透视下行内固定治疗37例为C形臂组,男24例,女13例,年龄(44.37±10.82)岁。合并有前环骨折患者42例,均采用经皮髂前下棘内置外固定架(internal fixation,INFIX)或耻骨上支螺钉固定骨盆前环。术后比较两组随访时间、置钉时间、并发症。比较两组Matta复位评价、Majeed疗效评价、CT分级及二次手术翻修率。结果：CT组置钉时间(32.63±7.33) min,短于C形臂组(52.95±10.64) min(t=-9.739,P＜0.05)。CT组随访时间(11.97±1.86)个月,C形臂组(12.03±1.71)个月,两组比较差异无统计学意义(P＞0.05)。两组术后并发症发生比较,差异无统计学意义(χ²=0.159,P＞0.05)。CT组Matta复位评价结果(Z=2.79,P＜0.05)、Majeed疗效评价结果(Z=2.79,P＜0.05)、CT分级(Z=2.83,P＜0.05)均优于C形臂组。CT组二次手术翻修率低于C形臂组(χ²=5.641,P＜0.05)。结论：术中滑轨CT联合C形臂辅助下经皮骶髂关节螺钉置入手术与传统C形臂透视相比,具有手术时间短、准确度及安全性高、术后二次翻修率显著下降等特点,是重建骨盆骨折后环稳定性的有效方法之一。     

超声引导下连续髂筋膜间隙阻滞用于老年髋部骨折患者围术期镇痛的研究

目的:研究超声引导下髂筋膜间隙阻滞对老年髋部骨折患者围手术期疼痛控制及术后并发症的影响。方法:选择2021年1月至2021年9月收治的老年髋部骨折手术患者127例,按照镇痛方法不同分为连续髂筋膜间隙阻滞组(F组)和静脉镇痛对照组(C组)。其中F组62例,男19例,女43例;年龄66~95(82.4±7.2)岁;股骨颈骨折25例,股骨转子间骨折37例。C组65例,男18例,女47例;年龄65~94(81.4±8.7)岁;股骨颈骨折29例,股骨转子间骨折36例。观察两组患者围术期不同时间点的疼痛视觉模拟评分(visual analogue scale,VAS)、简易精神状态评价量表(minimental state examination,MMSE)评分、警觉-镇静评分(observer''s assessment of alertness/sedation,OAA/S)、改良Bromage评分、术后并发症及患者住院期间情况。结果:F组实施阻滞后30 min、麻醉摆放体位时,术后6、24、48 h的静息及运动VAS低于C组(P<0.05)。F组术前12 h,术后1、3 d的MMSE评分及术后3 d的OAA/S评分高于C组(P<0.05)。F组不良反应发生率、需要额外镇痛人数低于C组(P<0.05)。F组围术期镇痛满意度及住院时间均优于C组(P<0.05)。两组患者在各时间点患肢Bromage评分及术后30 d死亡率比较,差异无统计学意义(P>0.05)。结论:超声引导下连续髂筋膜间隙阻滞可为老年髋部骨折患者提供安全、有效的围术期镇痛效果,改善术后认知功能,减少术后并发症,从而缩短住院时间,提高住院期间生活质量。     

股骨外侧壁在股骨粗隆间骨折的髓内与髓外固定中的生物力学研究

目的：观察股骨外侧壁的完整性对髓内与髓外固定治疗股骨粗隆间骨折的生物力学影响,指导临床选择内固定方式。方法：采用成人尸体同侧股骨标本12具,均造成股骨粗隆间骨折AO 分型A1型骨折,随机分为外侧壁完整PFNA组、外侧壁完整PF-LCP组、外侧壁破损PFNA组、外侧壁破损PF-LCP组,每组3具,4组股骨标本采用万能材料测试机进行压缩载荷实验,观察股骨标本的最大载荷力,并用游标卡尺测量骨折断端的压缩前后的间隔位移及骨折远、近端沿粗隆间的滑动位移进行相互比较。结果：外侧壁完整PFNA组的最大载荷力大于外侧壁完整PF-LCP组,并且外侧壁破损PFNA组的最大载荷力也大于外侧壁破损PF-LCP组,差异均具有统计学意义（P<0.05）;压缩前4组股骨标本的骨折端间隔距离相互比较差异无统计学意义（P>0.05）,压缩后外侧壁完整PFNA组的骨折端间隔距离、压缩前后的骨折端位移及骨折远、近端的滑动位移与外侧壁完整PF-LCP组相互比较差异均无统计学意义（P>0.05）,但外侧壁破损PFNA组的骨折端间隔距离、压缩前后的骨折端位移及骨折远、近端的滑动位移均小于外侧壁破损PF-LCP组,差异均具有统计学意义（P<0.05）.结论：髓内固定治疗股骨粗隆间骨折具有更强的载荷力,股骨外侧壁完整时髓内与髓外固定均有较强的稳固性,但股骨外侧壁破损时髓内固定具有更强的稳固性,可见髓内固定是治疗股骨粗隆间骨折的首选方式。     

颈椎椎体CT值在颈椎退行性疾病手术病人术前骨质量评估中的应用研究

目的 研究颈椎椎体CT值在颈椎退行性疾病术前骨质量评估中的应用价值。方法 回顾性分析2015年1月至2017年12月在北京大学第三医院骨科颈椎专业组接受颈椎手术治疗的939例颈椎退行性疾病病人,其中男484例,女455例,平均年龄为59岁。在PACS系统上测量C₂~C₇椎体中横断面的CT值,通过双能X线吸收法（dual-energy X-ray absorptiometry, DXA）获得L₁~L₄总的骨密度T值。分析C₂~C₇椎体CT值的变化规律、颈椎椎体CT值与L₁~L₄总的骨密度T值的相关性,并分别计算-2.5＜T值＜-1、T值≤-2.5时,C₂~C₇椎体CT均值的临界值。结果 C₂~C₇椎体的CT值分别为（363.43±92.52） HU、（340.44±80.73） HU、（338.37±86.92） HU、（333.43±87.49） HU、（289.98±76.60） HU、（259.43±62.59） HU,依次递减;C₂~C₇椎体CT值为（322.52±89.27） HU。L₁~L₄总的骨密度T值平均值为-0.73。C₂~C₇椎体的CT值与L₁~L₄总的骨密度T值呈正相关（r=0.487,P＜0.001）。-2.5＜T值＜-1时,C₂~C₇椎体CT均值的临界值为327 HU,采用该临界值筛查骨质减少的灵敏度为75.7%,特异度为59.8%。T值≤-2.5时,C₂~C₇椎体CT均值的临界值为269 HU,采用该临界值筛查骨质疏松的灵敏度为63.8%,特异度为80.8%。结论 颈椎退行性疾病手术病人的颈椎CT值自C₂至C₇递减;颈椎椎体CT值与DXA检查的骨密度T值呈正相关,有助于术前临床评估病人的骨质量。     

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.