微创经皮椎弓根植钉并同切口通道下减压治疗A3型胸腰椎骨折

目的探讨微创经皮椎弓根植钉并同切口通道下减压治疗A3型(AO分型)胸腰椎骨折的临床疗效。方法回顾分析2014年5月—2016年2月收治的43例符合选择标准纳入研究的伴或不伴有神经损伤,但需椎管减压的A3型胸腰椎爆裂骨折患者临床资料,其中21例行微创经皮椎弓根植钉并同切口通道下减压治疗(经皮组),22例行传统开放手术椎弓根螺钉内固定并椎板切除椎管治疗(开放组)。两组患者性别、年龄、致伤原因、骨折累及节段及术前美国脊柱损伤协会(ASIA)脊髓损伤分级、胸腰椎损伤评分系统(TLICS)评分、载荷分享评分、伤椎前缘和后缘高度百分比、伤椎后凸Cobb角及椎管侵占率等一般资料比较差异均无统计学意义(P0.05),具有可比性。记录并比较两组患者棘旁肌肉剥离长度、手术时间、术中出血量、术后引流量、患者术中X射线暴露次数、术后1 d切口疼痛视觉模拟评分(VAS);末次随访时行日本骨科协会(JOA)评分及腰痛VAS评分,并评价ASIA损伤级别恢复情况;检测术后伤椎前缘和后缘高度百分比、伤椎后凸Cobb角、椎管侵占率等影像学指标。结果经皮组剥离肌肉长度、术中出血量、术后引流量、术后1 d切口VAS评分均优于开放组(P0.05);两组手术时间比较差异无统计学意义(P0.05);但患者X射线暴露次数开放组优于经皮组(P0.01)。两组患者均获随访,随访时间12~19个月,平均15.1个月。所有患者均获得良好减压;均未发生医源性神经损伤、感染、内固定物松动或断裂等并发症。两组术后3 d伤椎前缘高度百分比、伤椎后缘高度百分比、伤椎后凸Cobb角、椎管侵占率均较术前显著改善(P0.05);两组间术后3 d上述指标比较以及末次随访时后凸Cobb角矫正丢失度比较,差异均无统计学意义(P0.05)。末次随访时经皮组腰椎JOA评分、腰痛VAS评分均显著优于开放组(P0.05)。末次随访时两组ASIA脊髓神经损伤分级E级以下者均较术前有1级及以上改善,两组间比较差异无统计学意义(Z=0.480,P=0.961)。结论微创经皮椎弓根植钉并同切口通道下减压术治疗伴或不伴有神经功能损伤的A3型胸腰椎爆裂骨折临床效果满意,且创伤小、恢复快、安全可靠。     

减压与不减压治疗无神经损伤症状胸腰段爆裂性骨折的疗效比较

目的比较减压与不减压治疗无神经损伤症状胸腰段爆裂性骨折的疗效。方法将81例无神经损伤症状胸腰段爆裂性骨折患者根据是否行椎管减压分为减压组(采用椎管减压行椎弓根螺钉内固定术,37例)和不减压组(采用椎管不减压行椎弓根螺钉内固定术,44例)。记录两组患者手术时间、术中出血量、术后引流量、术后卧床时间、术后住院时间、伤椎前缘高度、椎管受压占椎管面积百分比、后凸Cobb角等。结果 81例均获得12个月的随访。手术时间、术中出血量及术后引流量不减压组均明显少于减压组(P 0. 001);两组术后卧床时间和住院时间比较差异无统计学意义(P 0. 05)。末次随访时,两组伤椎前缘高度、椎管受压占椎管面积百分比、后凸Cobb角比较差异均无统计学意义(P 0. 05)。结论无神经损伤症状胸腰段爆裂性骨折患者减压或不减压治疗均可获得满意的疗效,但不减压手术创伤更小。     

后路微创通道下椎管减压内固定治疗胸腰椎骨折合并神经损伤的疗效分析

目的探讨后路微创通道下椎管减压内固定对胸腰椎骨折合并神经损伤的临床疗效。方法纳入2015-01-2017-01,于我院骨科治疗的82例胸腰椎骨折合并神经损伤患者,根据就诊顺序随机分为观察组与对照组,分别采用后路通道微创与开放式椎管减压+椎弓根螺钉固定治疗,记录两组患者手术相关指标并进行疗效对比。结果观察组手术出血量、引流量均显著低于对照组,住院时间显著短语对照组,差异有统计学意义(P0.05);观察组术后1周、3月的VAS评分、ODI指数显著低于对照组(P0.05),组间Cobb角、伤椎椎体前缘高度比的差异无统计学意义(P0.05);两组术后ASIA神经功能分级均显著改善,组间差异无统计学意义(P0.05);观察组切口感染率显著低于对照组(P0.05)。结论后路微创通道下椎管减压内固定治疗胸腰椎骨折合并神经损伤能获得与开放手术相当的神经功能恢复及后凸畸形矫正效果,且创伤小、患者术后疼痛及腰椎功能恢复较快,明显降低了切口感染率。     

经皮椎弓根钉内固定治疗胸腰椎骨折

目的通过与开放椎弓根钉内固定手术相比较,探讨经皮微创普通椎弓根钉内固定辅助系统治疗胸腰椎骨折的临床效果。方法自2008年1月至2012年12月将86例胸腰椎骨折随机分为两组(n=43),分别采用经皮普通椎弓根钉内固定(微创组)和开放椎弓根钉内固定(开放组)治疗胸腰椎骨折,比较两组伤椎前缘高度比值、矢状面Cobb角、手术时间、出血量及并发症等情况。结果术后所有患者随访6~48个月,平均18.6个月。微创组伤椎前缘高度比值平均从术前(47.5±8.6)%恢复至术后(90.3±5.8)%,Cobb角平均从术前(17.6±6.20)°恢复至术后(2.0±1.30)°,微创组术后伤椎前缘高度比值与开放组(91.7±5.0)%相比较差异无统计学意义(P0.05),微创组术后伤椎矢状面Cobb角与开放组(1.9±1.20)°相比较差异无统计学意义(P0.05),微创组手术时间平均(94.0±21.3)min,与切开组(98.5±16.5)min比较差异无统计学意义(P0.05)。微创组术中出血量平均(54.4±12.6)mL,与切开组(289.1±20.5)mL比较差异有统计学意义(P0.05)。除开放组1例出现切口感染外,两组未出现其他手术相关并发症。结论经皮普通椎弓根钉内固定辅助系统治疗胸腰椎骨折与开放性椎弓根钉内固定手术相比创伤小,出血少,患者恢复快,可达到开放复位同样的疗效。     

微创经皮经伤椎椎弓根钉内固定治疗无神经损伤胸腰椎骨折

目的评价微创经皮经伤椎椎弓根钉内固定治疗无神经损伤的胸腰椎骨折的临床疗效。方法对自2012-01—2015-10采用微创经皮经伤椎椎弓根钉内固定治疗的60例无神经损伤单节段胸腰椎骨折进行回顾性分析。比较术前、术后1周、末次随访时疼痛VAS评分、ODI指数、伤椎前缘高度比值、后凸Cobb角。结果本组获得随访12~24个月,平均18.2个月。术后1周各观察指标较术前明显改善,差异有统计学意义(P0.05);而末次随访时与术后1周伤椎前缘高度比值、Cobb角比较差异无统计学意义(P0.05)。结论微创经皮经伤椎椎弓根钉内固定治疗无神经损伤胸腰椎骨折是安全有效的手术方法,与开放手术比较具有创伤小、出血少及术后恢复快等优点。     

减压和非减压治疗无神经症状椎管内占位胸腰椎骨折的对比研究

目的比较后路开窗减压与非减压手术治疗无神经症状椎管内占位胸腰椎骨折的疗效。方法回顾分析2008年10月—2015年10月收治的符合选择标准的97例椎管受压占椎管面积1/3~1/2的无神经症状胸腰椎骨折患者,其中采用后路开窗减压手术51例(减压组),采用后路非减压手术46例(非减压组)。两组患者性别、年龄、致伤原因、受伤节段、胸腰椎损伤分类及严重程度评分(TLICS)、合并伤、受伤至手术时间以及术前伤椎前缘相对高度、后凸Cobb角、椎管受压占椎管面积百分比、疼痛视觉模拟评分(VAS)、Oswestry功能障碍指数(ODI)、日本骨科协会(JOA)评分等一般资料比较,差异均无统计学意义(P0.05),具有可比性。记录并比较两组患者手术时间、术中出血量、术后引流量、术后卧床时间、住院时间;术前、术后3 d及术后1年伤椎前缘相对高度、后凸Cobb角、椎管受压占椎管面积百分比及VAS评分、ODI、JOA评分。结果非减压组手术时间、术中出血量及术后引流量均明显少于减压组(P0.05);两组术后卧床时间和住院时间比较差异无统计学意义(P0.05)。减压组有4例发生术后脑脊液漏,经保守治疗后治愈;两组切口均Ⅰ期愈合,均未发生神经损伤、切口感染并发症。所有患者均获随访,随访时间10~18个月,平均11.7个月。两组椎体高度恢复满意,均无继发后凸畸形及继发神经症状加重。两组术后3 d及1年各影像学指标及疗效评分均较术前显著改善,差异有统计学意义(P0.05);术后1年两组椎管受压占椎管面积百分比、VAS评分、ODI均显著低于术后3 d(P0.05),JOA评分均显著高于术后3 d(P0.05);术后1年伤椎前缘相对高度非减压组显著高于术后3 d(P0.05),减压组与术后3 d比较差异无统计学意义(P0.05)。除术后3 d非减压组椎管受压占椎管面积百分比及JOA评分高于减压组,VAS评分和ODI显著低于减压组,比较差异有统计学意义(P0.05)外,其余指标组间比较差异无统计学意义(P0.05)。结论与后路开窗减压手术相比,后路非减压手术具有术中出血少、手术创伤小、术后疼痛轻等优点;在严格掌握手术适应证情况下,后路非减压手术是治疗椎管内占位达椎管面积1/3~1/2的无神经症状胸腰椎骨折有效方法之一。     

微创置钉后通道入路椎管减压植骨融合术治疗胸腰椎骨折伴神经损伤研究

目的研究微创置钉后通道入路椎管减压植骨融合术治疗胸腰椎骨折伴神经损伤的临床效果。方法选取本院于2015年6月至2018年6月收治的70例胸腰椎骨折伴神经损伤患者进行研究,按照随机数字表法,随机分成研究组和对照组,每组各35例。对照组行传统开放手术,研究组行微创置钉后通道入路椎管减压植骨融合术。观察并比较两组患者围手术期各观察指标情况、影像学参数评价结果、神经功能恢复情况以及并发症发生情况。结果术后,研究组术中出血量、术后引流量、自体血回输、术后止痛药应用、住院时间以及视觉模拟评分法(VAS,Visual Analogue Score)评分情况均显著低于对照组,手术时间明显高于对照组(P0.05)。术后1周,两组患者矢状面Cobb角、伤椎前缘高度以及椎管容积均较术前显著改善(P0.05),但两组比较差异无统计学意义(P0.05)。术后,两组患者美国脊柱损伤协会(ASIA)神经功能分级较术前显著改善(χ_1~2=20.852,P0.001;χ_2~2=11.785,P=0.019),但两组比较差异无统计学意义(P0.05)。结论微创置钉后通道入路椎管减压植骨融合术治疗伴神经损伤的胸腰椎骨折患者疗效显著,且在出血量、住院时间、创伤等方面较传统开放术式更具优势。     

两种不同术式治疗胸腰椎骨折的对比研究

目的探讨微创经皮与开放短节段椎弓根螺钉固定结合伤椎内植骨治疗胸腰椎骨折的临床疗效。方法回顾性分析2013年1月至2015年1月收治的60例胸腰椎爆裂或压缩骨折患者的临床资料,其中30例采用微创经皮椎弓根螺钉固定结合伤椎内植骨治疗,30例采用开放短节段椎弓根螺钉固定结合伤椎内植骨治疗,观察两组患者的手术时间、术中出血量,比较两组患者手术前后疼痛视觉模拟评分(visual analog scale,VAS)、伤椎前缘高度压缩率、椎体Cobb角情况。结果 60例患者均获随访,随访时间8~18个月,平均12.8个月。所有患者术后切口均Ⅰ期愈合,无感染、深静脉血栓形成等并发症发生,无内固定物松动、断裂。微创组手术时间、术中出血量较开放组明显减少,差异有统计学意义(P0.05)。两组患者术后1周、末次随访VAS评分、伤椎前缘高度压缩率及椎体Cobb角较术前均有改善,差异有统计学意义(P0.05);术后同组内不同时间点伤椎前缘高度压缩率、椎体Cobb角比较差异无统计学意义(P0.05);术后两组患者同一时间点伤椎前缘高度压缩率、椎体Cobb角比较差异无统计学意义(P0.05)。微创组术后1周疼痛缓解较开放组明显,差异有统计学意义(P0.05);末次随访时两组患者疼痛程度相当,差异无统计学意义(P0.05)。结论微创经皮椎弓根螺钉固定结合伤椎内植骨治疗胸腰椎骨折具有出血少、创伤小、用时少等优点,能有效恢复并维持伤椎高度,矫正脊柱后凸畸形,对伤椎高度恢复及脊柱后凸畸形矫正与开放手术相当,短期内对术后患者疼痛缓解优于开放手术。     

经皮伤椎置入万向椎弓根螺钉治疗胸腰椎骨折

[目的]探讨经皮伤椎置入万向椎弓根螺钉治疗胸腰椎骨折的临床疗效。[方法]选择2015年1月～2016年12月收治的无神经损伤的胸腰椎骨折患者68例。随机分为两组:经伤椎组35例,经伤椎置入万向钉;跨伤椎组33例,跨伤椎置入万向钉。两组患者年龄、性别、骨折节段及类型、受伤原因等一般资料差异无统计学意义(P0.05)。比较两组患者不同时间点的VAS评分、JOA评分、ODI指数、Cobb角及伤椎前缘高度比。[结果]两组手术时间、术中出血量、下地时间比较差异均有统计学意义(P0.05),两组术后引流量比较差异无统计学意义(P0.05)。两组患者切口均一期愈合,无相关并发症。两组患者均获随访,经伤椎组随访18～28个月,平均(22.52±2.13)个月;跨伤椎组随访17～29个月,平均(21.23±2.35)个月。两组患者均无内固定断裂。两组患者VAS评分,术后1周、末次随访时较术前均明显改善(P0.05);但末次随访时VAS评分经伤椎组(0.57±0.502)和跨伤椎组(1.27±0.719)之间差异有统计学意义(P0.05)。影像测量方面,经伤椎组伤椎前缘高度比、Cobb角,术后1周、末次随访时均较术前明显改善,差异有统计学意义(P0.05)。组间比较伤椎前缘高度矫正度、Cobb角矫正度,经伤椎组优于跨伤椎组(P0.05);组间比较伤椎前缘高度丢失度、Cobb角丢失度,经伤椎组小于跨伤椎组(P0.05)。[结论]经皮伤椎置入万向钉治疗胸腰椎骨折可以良好矫正骨折局部后凸、防止矫正角度丢失;经皮伤椎置入万向钉治疗效果优于跨伤椎置入万向钉。     

270°椎管减压椎体前中柱重建治疗严重胸腰椎骨折

[目的]探讨270°椎管减压椎体前中柱重建治疗严重胸腰椎骨折的疗效。[方法]回顾分析2010年1月～2016年12月收治的46例严重胸腰椎骨折患者。根据减压范围,分为270°椎管减压组19例,360°椎管减压组27例。比较两组围手术期、随访与影像资料。[结果]所有患者均顺利完成手术,无严重并发症。270°组手术时间、术中出血量、术后引流量及异体血输入量均显著少于360°组(P0.05)。随访18～60个月,平均(45.34±10.41)个月。两组末次随访时VAS评分均较术前显著减少(P0.05),但相同时间点两组间差异均无统计学意义(P0.05)。两组患者末次随访AISA分级均较术前显著改善(P0.05),相同时间点两组间差异均无统计学意义(P0.05)。影像评估方面,与术前相比两组术后椎体前缘高度显著增加(P0.05),Cobb角显著减小,椎管占位率显著减小(P0.05)。相同时间点,两组间椎体前缘高度、伤椎Cobb角及椎管占位率的差异均无统计学意义(P0.05)。至末次随访时,两组损伤节段均达到骨性融合,未出现内固定失败。[结论]对于严重胸腰椎骨折,行270°与360°椎管减压均可彻底减压,取得良好的临床效果。但270°椎管减压具有手术时间短,术中出血、术后引流量及异体血输入量少及脊柱稳定性破坏小等优点。     

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.     

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.