单、双侧经皮椎体后凸成形术治疗骨质疏松性椎体压缩骨折的疗效

目的:探讨经单侧或双侧椎弓根途径行椎体后凸成形术(PKP)治疗骨质疏松性椎体压缩骨折的临床疗效。方法:回顾性分析2007年6月～2008年11月在我院行PKP治疗的97例(140个椎体)骨质疏松性椎体压缩骨折患者的临床资料,按术中经单侧或双侧椎弓根途径进行分组。单侧组均为单侧穿刺骨水泥注射过椎体中线者,共58例85个椎体,男13例,女45例,平均年龄65.3岁,单椎体36例,两椎体17例,三椎体5例。双侧组39例55个椎体,男5例,女34例,平均年龄67.1岁,单椎体24例,两椎体14例,三椎体1例。观察患者手术前后VAS评分变化、椎体平均高度、局部Cobb角改善及近远期并发症的发生情况。结果:所有患者均顺利完成手术。单侧组手术时间45±16min,骨水泥注入量3.1±1.7ml;双侧组手术时间62±27min,骨水泥注入量4.2±2.1ml,两组间比较有显著性差异(P<0.05);两组术后及末次随访时VAS评分均较术前明显降低(P<0.05),两组间比较差异无统计学意义(P>0.05);术后两组椎体平均高度及局部Cobb角较术前均有显著恢复(P<0.05),组间比较差异无显著性(P>0.05);单侧组骨水泥渗漏及邻近椎体再骨折的发生率为14.12%,双侧组为16.36%,差异亦无显著性(P>0.05)。结论:经单侧椎弓根途径穿刺骨水泥过椎体中线注射治疗骨质疏松性椎体压缩骨折可取得双侧穿刺同样满意的临床效果,且具有手术时间短、骨水泥渗漏率低等优点。     

单、双侧穿刺经皮椎体后凸成形术治疗老年骨质疏松性椎体压缩骨折的疗效比较

目的 比较单、双侧穿刺经皮椎体后凸成形术(PKP)治疗老年骨质疏松性椎体压缩骨折的疗效。方法 将62例行PKP治疗的老年骨质疏松性椎体压缩骨折患者按单、双侧穿刺不同分为单侧组(32例)和双侧组(30例)。比较两组骨水泥注入量及渗漏情况、术中X线透视时间、手术时间、术后疼痛VAS评分以及影像学指标。结果 患者均获得随访,时间6～13个月。骨水泥注入量、术中X线透视时间、手术时间单侧组均少(短)于双侧组(P<0.01)。术后疼痛VAS评分两组比较差异无统计学意义(P>0.05)。单侧组3例、双侧组7例发生骨水泥渗漏,但均无临床症状。伤椎前缘高度、伤椎中央高度、Cobb角两组术后均较术前改善(P<0.05),两组术后比较差异均无统计学意义(P>0.05)。结论 单、双侧穿刺PKP治疗老年骨质疏松性椎体压缩骨折均能改善患者疼痛症状、纠正脊柱后凸畸形,恢复伤椎高度,单侧穿刺术中X线透视时间和手术时间更短、骨水泥注入量更少。     

弯角椎体成形术治疗胸腰椎骨质疏松性椎体压缩骨折的疗效分析

目的 :评估分析弯角椎体成形术(percutaneous curved vertebroplasty,PCVP)治疗胸腰椎骨质疏松性椎体压缩骨折的临床疗效。方法:选取96例胸腰椎骨质疏松性椎体压缩骨折患者,共128节病椎,将其分为弯角组(36例,43节)、单侧组(32例,42节)及双侧组(28例,43节),分别行PCVP及单侧、双侧椎弓根入路椎体成形术。3组患者的性别、年龄、骨密度及病椎节段分布均无统计学差异(P0.05)。统计3组手术时间、X线曝光次数、骨水泥注入量及术前、术后24h、术后3个月疼痛视觉模拟评分(VAS评分),术后复查CT评价骨水泥渗漏率,进行统计学分析。结果:弯角组与单侧组的手术时间、X线曝光次数均明显少于双侧组,差异有统计学意义(P0.05),弯角组和单侧组无显著性差异(P0.05)。弯角组、单侧组、双侧组的骨水泥注入量比较,双侧组最多(6.2±1.5ml),弯角组次之(4.5±1.3ml),单侧组最少(3.4±1.2ml),组间两两比较差异有统计学意义(P0.05)。弯角组、单侧组、双侧组的骨水泥渗漏率比较,单侧组(28.6%,12/42)最高,双侧组(18.6%,8/43)次之,弯角组(9.3%,4/43)最低,组间两两比较差异有统计学意义(P0.05)。3组患者术后疼痛均明显缓解,术后24h及术后3个月VAS评分均明显低于术前(P0.05),术后24h及术后3个月VAS评分比较无显著性差异(P0.05),同时间点组间比较亦无显著性差异(P0.05)。结论:PCVP具有操作简单、手术时间短、X线透视次数少、创伤小、并发症少等优势,是治疗胸腰椎骨质疏松性椎体压缩骨折的有效微创手术方法。     

单侧与双侧经皮椎体成形术治疗椎体压缩性骨折的前瞻性研究

目的 对单侧和双侧经皮椎体成形术(PVP)治疗骨质疏松性椎体压缩性骨折的疗效进行分析比较.方法 对48例L1椎体骨质疏松性压缩骨折进行前瞻性随机对照,应用单双侧椎体成形术治疗各24例,对术后短期及长期疗效进行统计学分析对比.结果 无论是单侧还是双侧椎体成形术,均能够有效缓解疼痛,术后较术前,差异有统计学意义(P<0.05),且两组之间无显著性差异(P>0.05);两组均增加了术后邻近椎体骨折的风险,两组风险差异无统计学意义(P>0.05).结论 单侧椎体成形术在治疗骨质疏松性椎体压缩性骨折中,能取得和双侧椎体成形术相近似的效果.     

经皮椎体成形术和经皮椎体后凸成形术治疗骨质疏松性椎体压缩骨折

目的:观察经皮椎体成形术(percutaneous vertebroplasty,PVP)和经皮椎体后凸成形术(percutanous kyphoplasty,PKP)治疗骨质疏松性椎体压缩骨折的疗效。方法:2007年10月～2009年4月收治骨质疏松性椎体压缩骨折患者106例,其中61例82个椎体接受PVP治疗,男21例29个椎体,女40例53个椎体,年龄65～96岁,平均78.3岁;45例55个椎体接受PKP治疗,男17例21个椎体,女28例34个椎体,年龄68～90岁,平均77.1岁。术前及术后1d进行疼痛视觉类比评分(VAS),测量伤椎高度,随访伤椎高度丢失情况,记录骨水泥渗漏及随访期间邻近椎体骨折情况。结果:PVP组术前和术后1d VAS分别为6.7±1.4分和2.1±0.7分,PKP组分别为6.9±1.2分和2.2±0.9分,每组术后VAS与术前比较有统计学差异(P<0.05),同时间点组间比较无统计学差异(P>0.05)。PVP组55例、PKP组41例获得随访,随访时间为12～36个月,平均18个月。PVP组和PKP组术后伤椎高度分别较术前增加2.4±1.8mm和9.2±2.2mm,术后12个月随访伤椎高度分别丢失0.8±0.5mm和1.9±0.8mm,两组比较有统计学差异(P<0.05)。PVP组术中骨水泥渗漏28例33个椎体,PKP组15例17个椎体,PKP组骨水泥渗漏率明显低于PVP组(P<0.05)。随访期间PVP组发生相邻椎体骨折9例,PKP组6例,两组相邻椎体骨折发生率无统计学差异(P>0.05)。结论:PVP和PKP治疗骨质疏松性椎体压缩骨折的止痛效果均较好;PKP的复位效果优于PVP,较少发生骨水泥渗漏,但术后椎体高度再次丢失较明显;两者术后相邻椎体骨折发生率无明显差异。     

弯角经皮椎体成形术治疗骨质疏松性椎体压缩骨折的疗效分析

目的探讨弯角经皮椎体成形术(PCVP)治疗骨质疏松性椎体压缩骨折的临床疗效。方法回顾性分析自2018-04—2019-02诊治的75例骨质疏松性椎体压缩骨折,36例采用PCVP治疗(观察组),39例采用传统单侧经皮椎体成形术(PVP)治疗(对照组),比较2组手术时间、术中透视次数、骨水泥注入量、骨水泥双侧分布情况、骨水泥渗漏情况,以及术前、术后1个月、末次随访时疼痛VAS评分、ODI指数。结果 75例均获得随访,随访时间平均5.5(5~7)个月,无椎弓根刺破、神经、血管损伤等并发症。2组手术时间、术中透视次数比较差异无统计学意义(P>0.05)。观察组骨水泥注入量较对照组多,骨水泥渗漏例数较对照组少,骨水泥双侧分布情况较对照组优,差异有统计学意义(P <0.05)。观察组与对照组术后1个月、末次随访时疼痛VAS评分及ODI指数均较术前明显改善(P <0.05),而2组间比较差异无统计学意义(P>0.05)。结论采用PCVP治疗骨质疏松性椎体压缩骨折可增加骨水泥注入量及双侧分布率,降低骨水泥渗漏风险,术后可取得良好恢复效果,值得临床推广。     

单侧与双侧椎体后凸成形术治疗多椎体骨质疏松性压缩骨折疗效分析

目的 分析单侧与双侧球囊扩张椎体后凸成形术(KP)治疗多椎体骨质疏松性压缩骨折的疗效.方法 对2002年5月至2007年6月,采用KP治疗并且获得1年以上随访的41例多椎体骨质疏松性压缩骨折患者,按手术是单侧或双侧进行分组.单侧手术组17例40个椎体,其中男性3例,女性14例;年龄52～91岁,平均70.4岁.双侧手术组24例53个椎体,其中男性4例,女性20例;年龄61～87岁,平均72.4岁.所有患者均在"C"型臂X线机引导下,经皮穿刺完成手术.术后观察症状改善、骨折复位及后凸矫正、并发症发生等情况,并进行统计学对比分析.结果 所有患者手术均顺利完成.单侧手术组平均手术时间(86±32)min,平均每椎体注射骨水泥(3.9±1.6)ml,术后平均随访(32.5±17.2)个月;双侧手术组平均手术时间(120±26)min,平均每椎体注射骨水泥(5.4±2.1)ml,术后平均随访(30.7±14.3)个月.疼痛VAS评分:单侧手术组术前为7.4±2.1,术后为2.7±1.9,末次随访为3.1±2.2,手术前后差异有统计学意义(P＜0.05);双侧手术组术前为7.9 ±2.1,术后为2.3±2.5,末次随访为2.7±2.2,手术前后差异有统计学意义(P＜0.05).两组术后椎体前缘、中部高度均比术前有显著增加,且维持至末次随访,差异均有统计学意义(P＜0.05).椎体后凸角单侧手术组平均矫正7.2°±4.9°,双侧手术组平均矫正7.3°±5.9°,各组手术前后比较,差异有统计学意义(P＜0.05).而两组间上述各指标对应比较,差异无统计学意义.两组术后SF-36生命质量调查表8个领域中有6个显著提高.41例中发生骨水泥渗漏6例,肺栓塞1例.结论 单侧或双侧KP治疗多椎体骨质疏松性压缩骨折均可获得满意的治疗效果.     

手法复位联合经皮椎体成形术治疗合并椎体裂隙征骨质疏松性椎体压缩骨折

目的:探讨手法复位联合经皮椎体成形术治疗合并椎体裂隙征骨质疏松性椎体压缩骨折(OVCFs)的临床效果。方法:对2014年1月至2017年1月收治的合并椎体裂隙征骨质疏松性椎体压缩骨折94例患者进行回顾性分析,根据手术方式分为A、B两组。A组45例,采用单侧入路PVP治疗,其中男17例,女28例,年龄(75.35±11.82)岁,骨密度T值为(-4.28±0.65) g/cm~3;B组49例,采用手法复位联合单侧入路PVP治疗,其中男19例,女30例,年龄(76.79±9.64)岁,骨密度T值为(-4.33±0.72) g/cm~3。记录两组患者的手术时间、骨水泥注入量、并发症;分析两组患者术后1、12、18个月的VAS、ODI评分;比较两组患者术后即刻和术后12、18个月椎体高度、后凸Cobb角;观察骨水泥在椎体内的分布并计算其分布优良率。结果:两组患者的手术时间比较差异无统计学意义。骨水泥注入量A组为(8.42±1.24) ml,B组为(9.19±1.09) ml,两组差异有统计学意义(P0.05)。两组患者术中均无脊髓神经根损伤,术后均无肺栓塞、骨水泥毒性反应、感染等并发症。骨水泥渗漏A组出现5例,B组4例,均未引起相应临床症状,未予特殊处理。骨水泥分布A组优25例,良19例,差1例,B组优45例,良4例;骨水泥分布优良率B组高于A组(P0.05)。术前及术后1、12、18个月VAS、ODI评分A组分别为8.29±0.74、2.59±0.14、3.75±0.38、3.84±0.88和40.04±3.16、9.24±2.82、12.27±2.64、15.83±2.58,B组分别为8.22±0.82、2.54±0.19、2.81±0.23、2.82±0.45和39.98±2.05、9.16±2.10、9.46±2.41、9.76±2.46;术后1个月VAS、ODI评分两组比较差异无统计学意义(P0.05),但术后12、18个月A组高于B组(P0.05)。术前、术后即刻、术后12个月及18个月椎体高度、Cobb角A组分别为(59.17±1.42)%、(85.95±2.19)%、(75.27±3.45)%、(68.34±2.24)%和(23.83±3.37)°、(15.26±2.61)°、(17.63±2.16)°、(19.46±2.54)°,B组分别为(59.31±1.87)%、(89.19±2.53)%、(88.62±2.51)%、(88.59±2.62)%和(24.72±3.78)°、(14.91±2.28)°、(15.48±2.55)°、(15.86±2.81)°。术后即刻椎体高度B组大于A组,Cobb角B组小于A组(P0.05),在随访中,B组椎体高度无明显变化,A组椎体高度塌陷(P0.05)。结论:在治疗合并椎体裂隙征骨质疏松性椎体压缩骨折中,使用手法复位联合经皮椎体成形术较单独使用经皮椎体成形术,能够有效防止椎体再塌陷,提高患者的远期疗效。     

骨水泥单侧与双侧分布对椎体后凸成形术疗效影响

目的探讨骨水泥单侧与双侧分布对椎体后凸成形术治疗骨质疏松性椎体压缩骨折临床疗效的影响。方法对42例骨质疏松性椎体压缩骨折患者经单侧穿刺行经皮椎体后凸成形术,依据骨水泥是否过中线分布分为两组,单侧组12例(12个椎体),双侧组30例(30个椎体),观察两组手术前后VAS评分、椎体平均高度、局部Cobb角以及术椎、非术椎椎体再骨折发生情况。结果单侧组与双侧组术后及随访时VAS评分均较术前明显降低(P0.05),组间比较差异无统计学意义(P0.05);术后两组椎体平均高度及局部Cobb角较术前均有显著恢复(P0.05),组间比较差异无统计学意义(P0.05);两组邻近椎体再骨折的发生率比较差异无统计学意义(P0.05),而术椎椎体再骨折比较差异有统计学意义(P0.05)。结论无论骨水泥是否过中线分布,均可取得有效的临床效果,且并未增加邻近椎体骨折的发生率;但单侧骨水泥分布有可能造成强化椎体再骨折;骨水泥过中线分布时临床疗效良好。     

单、双侧经皮椎体成形术治疗骨质疏松性椎体压缩骨折

目的探讨经单、双侧椎弓根途径行经皮椎体成形术治疗骨质疏松性椎体压缩骨折的临床疗效。方法回顾分析2009年2月至2011年2月在我院行经皮椎体成形术治疗的47例骨质疏松性椎体压缩骨折患者的临床资料。随机分成两组,分别采用单侧或双侧椎弓根途径行经皮椎体成形术。单侧组25例51个椎体（T11 11个、T12 16个、L1 15个、L2 9个）,男10例,女15例,年龄56～77岁,平均66．9岁。双侧组22例45个椎体（T11 10个、T12 13个、L1 13个、L2 9个）,男8例,女14例,年龄57～80岁,平均68．7岁。随访1年,观察患者手术前后VAS评分、SF．36评分、椎体平均高度变化及骨水泥渗漏。结果所有病例均顺利完成,无肺栓塞、神经根损伤等严重并发症。单侧穿刺组每个椎体的手术时间为27～46min,平均36min。每个椎体骨水泥注入量为3—5mL,平均3．8mL。双侧穿刺组每个椎体的手术时间为48～89min,平均69min。每个椎体骨水泥注入量为4～7mL,平均5．9mL。单侧穿刺组51个椎体中10个椎体发生骨水泥渗漏（19．6％）,双侧穿刺组45个椎体中17个椎体发生骨水泥渗漏（37．8％）,两组骨水泥渗漏差异有统计学意义（P〈0．05）。术前两组VAS评分、SF-36评分无统计学意义,术后3d及术后1年两组VAS评分、sF一36评分均较术前明显改善（P〈0．05）,但两组间比较无统计学意义。两组手术前后椎体平均高度均无明显变化。结论单、双侧经皮椎体成形术治疗骨质疏松性椎体压缩骨折均可取得同样满意的临床效果,但单侧经皮椎体成形术在手术时间、安全性上更具优势,更适合在广大基层医院推广普及。     

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.