改良跗骨窦切口解剖型锁定钢板内固定治疗Sanders Ⅲ-Ⅳ型跟骨骨折

目的:探讨改良跗骨窦切口解剖型锁定钢板内固定治疗SandersⅢ-Ⅳ型跟骨骨折临床疗效。方法:2015年2月至2016年10月采用改良跗骨窦切口解剖型锁定钢板内固定治疗SandersⅢ-Ⅳ型跟骨骨折35例,其中男22例,女13例;年龄22～68(42.3±12.7)岁;根据Sanders分型,Ⅲ型23例,Ⅳ型12例。观察术后并发症情况,比较手术前后跟骨B?hler角、Gissane角改变情况,并于术后12个月时采用Maryland足功能评分标准评价患足功能恢复情况。结果:35例患者获得随访,时间12～20(14.5±2.0)个月。切口长度4.0～5.5(4.7±0.4)cm。1例切口浅表感染,2例切口延迟愈合,腓肠神经损伤1例,随访无钢板外露、松动,无骨折复位丢失并发症。切口愈合时间14～28(15.4±4.7)d,骨折愈合时间8～14(9.8±1.9)周。B?hler角由术前的(9.81±14.28)°恢复至术后3 d的(26.35±11.04)°、术后12个月的(25.96±10.79)°,差异有统计学意义(P0.05)。Gissane角由术前的(122.54±16.79)°恢复至术后3 d的(120.85±11.88)°、术后12个月的(120.62±11.44)°,差异有统计学意义。Maryland评分由术前的12.66±4.10提高至术后12个月的92.20±7.82,其中优32例,良2例,可1例。结论 :改良跗骨窦切口解剖型锁定钢板内固定治疗SandersⅢ-Ⅳ型跟骨骨折,切口小,软组织损伤程度低,并可获得良好的骨折复位与固定,是SandersⅢ-Ⅳ型跟骨骨折有效的微创治疗方法。     

撬拨复位拉力螺钉内固定与小切口复位接骨板内固定治疗跟骨骨折的病例对照研究

目的:比较单纯撬拨复位拉力螺钉内固定与小切口复位接骨板内固定治疗跟骨骨折的临床疗效。方法 :回顾性分析2015年6月至2018年6月收治的88例(98足)跟骨骨折患者的临床资料。根据骨折分型及治疗方法不同分为撬拨复位拉力螺钉内固定术组(A组)50例,男32例,女18例;年龄(32.6±6.7)岁;SandersⅡ-Ⅲ型30例,SandersⅣ型20例。小切口复位接骨板内固定术组(B组)48例,男30例,女18例;年龄(31.9±7.2)岁;SandersⅡ-Ⅲ型28例,SandersⅣ型20例。分别于术前、术后1个月及1年比较两组患者的B觟hler角、Gissane角及AOFAS评分以评价其临床疗效。结果:所有患者获得随访,时间13～24(14.6±6.3)个月。术后两组B觟hler角、Gissane角及AOFAS评分均得到不同程度改善。对于SandersⅡ-Ⅲ型患者,两组术前、术后1个月及1年B觟hler角、Gissane角比较差异无统计学意义;术后1年AOFAS评分比较差异无统计学意义。对于SandersⅣ型患者,B组术后1个月、1年时B觟hler角[(35.40±1.85)°、(35.15±1.90)°]和Gissane角[(127.80±5.49)°、(127.00±3.06)°]高于A组B觟hler角[(27.85±3.42)°、(27.25±1.80)°]和Gissane角[(118.00±4.13)°、(117.50±5.04)°](P0.05);两组术后1个月、1年时B觟hler角、Gissane角均较术前提高(P0.05); B组术后1年AOFAS评分91.00±5.46高于A组84.50±4.64(P0.05)。结论:对于SandersⅡ-Ⅲ型中度跟骨骨折,两种治疗方法疗效相当;但对于SandersⅣ型重度跟骨骨折,与撬拨复位拉力螺钉内固定术相比,小切口复位接骨板内固定术可获得更好的复位和可靠固定,改善患足功能。     

锁定接骨板内固定治疗移位的关节内跟骨骨折

目的 探讨锁定接骨板内固定治疗移位的关节内跟骨骨折的效果。方法 对49例(58足)移位的跟骨关节内骨折(SandersⅡ、Ⅲ、Ⅳ型)采用切开复位锁定接骨板内固定术治疗,术中关节面复位后跟骨外侧放置跟骨锁定接骨板。手术前后测量Bhler角和Gissane角,评价跟骨骨折的复位情况。结果 患者均获随访,时间6~28个月。患者切口均无严重感染和广泛的皮肤坏死;骨折均愈合,时间3.5~4.5个月。术后6个月复查X线片显示Bhler角和Gissane角分别为28.3°±6.1°和125.7°±8.5°,与术前比较差异均有统计学意义(P<0.05)。术后功能按Maryland足部评价系统评分:优40足,良14足,差4足,优良率93.1%。结论 切开复位锁定接骨板内固定术治疗移位的关节内跟骨骨折手术方法简单,疗效满意。     

切开撬拨复位结合磷酸钙陶瓷植骨治疗Sanders Ⅱ型跟骨骨折

目的探讨切开撬拨复位结合磷酸钙陶瓷植骨治疗SandersⅡ型跟骨骨折的临床疗效。方法2003年1月～2007年3月,采用切开撬拨复位斯氏针固定并结合磷酸钙陶瓷植骨治疗SandersⅡ型跟骨骨折32例38足,手术前后评价跟骨B hler角,Gissane角、跟骨宽度的改善情况,随访期间观察并发症,采用Maryland评分评价患足功能。结果6例伤口愈合不良,2例术后足背外侧麻痛感,3例斯氏针松动脱出。术前B hler角、Gissane角、跟骨宽度分别为(14.3±5.2)°、(105.3±8.6)°、(39.6±3.4)mm,术后分别为(32.8±3.5)°、(123.2±6.5)°、(32.4±1.6)mm,经统计学分析手术前后差异有显著性(P<0.01)。经平均16个月的随访,按Maryland足功能评分标准:优16例,良12例,可4例,优良率87.5%。结论切开撬拨复位结合磷酸钙陶瓷植骨治疗SandersⅡ型跟骨骨折,可获得良好的复位和固定,仍可作为理想的治疗方法之一。     

跗骨窦小切口撬拨复位克氏针内固定治疗Sanders Ⅲ型跟骨骨折

目的 :探讨跗骨窦小切口撬拨复位克氏针内固定治疗SandersⅢ型跟骨骨折的疗效。方法:自2013年9月至2015年12月采用跗骨窦小切口撬拨复位克氏针固定治疗SandersⅢ型跟骨骨折患者22例,均为单足,其中男18例,女4例;年龄20~65(41.73±12.46)岁。观察并比较手术前后B?hler角、Gissane角及跟骨宽度的变化,术后12个月采用Maryland足部功能评分系统进行疗效评价,记录相关并发症。结果:所有患者获随访18~36(27.05±4.92)个月;患者骨折均正常愈合,愈合时间(10.73±1.24)周。B?hler角由术前的(11.36±5.92)°恢复到术后的(33.36±3.99)°,差异有统计学意义(P0.001);Gissane角术前(99.23±8.61)°与术后(114.64±6.93)°比较差异有统计学意义(P0.001);跟骨宽度由术前(46.59±1.40)mm恢复至术后3个月的(42.15±0.75)mm,差异有统计学意义(P0.001);术后12个月Maryland足部功能评分为95.05±6.86,优16例,良5例,差1例。患者术后无切口感染、皮缘坏死及骨髓炎发生。结论:跗骨窦小切口撬拨复位克氏针内固定治疗SandersⅢ型跟骨骨折疗效满意,具有手术创伤小、操作简单、跟距后关节面暴露充分、易于取出、切口并发症少等优点。同时,跗骨窦小切口术中需仔细操作辨认,保护腓肠神经、肌腱。     

骨折撑开器辅助开放复位治疗粉碎性跟骨骨折

[目的]探讨应用骨折撑开器辅助开放复位接骨板内固定治疗粉碎性跟骨骨折的方法及临床疗效。[方法]将2010年10月²012年10月期间收治的35例粉碎性跟骨骨折患者纳入研究,常规行影像学检查明确骨折类型,依据Sanders分型,本组最终获随访的31例患者中III型23例,Ⅳ型8例,所有患者均采用切开复位接骨板内固定方式治疗,术中应用骨折撑开器辅助复位,术后观察切口愈合及并发症情况,复查X线片及CT扫描评价骨折复位情况(Bhler角,Gissanes角,关节面台阶),末次随访时应用美国足踝外科学会AOFAS评分标准评估疗效。[结果]本组31例术后获得122012年10月期间收治的35例粉碎性跟骨骨折患者纳入研究,常规行影像学检查明确骨折类型,依据Sanders分型,本组最终获随访的31例患者中III型23例,Ⅳ型8例,所有患者均采用切开复位接骨板内固定方式治疗,术中应用骨折撑开器辅助复位,术后观察切口愈合及并发症情况,复查X线片及CT扫描评价骨折复位情况(Bhler角,Gissanes角,关节面台阶),末次随访时应用美国足踝外科学会AOFAS评分标准评估疗效。[结果]本组31例术后获得12²4个月的随访,平均(18.8±0.91)个月。2例患者术后出现了切口延迟愈合,经局部换药处理获得治愈,骨折均在1024个月的随访,平均(18.8±0.91)个月。2例患者术后出现了切口延迟愈合,经局部换药处理获得治愈,骨折均在10¹2周内获得愈合〔平均(10.6±0.45)周〕,至末次随访时未观察到感染、内固定失败、畸形愈合发生,9例观察到创伤性关节炎征象。AOFAS评分平均(79.7±1.54)分,其中优4例,良19例,可7例,差1例。[结论]应用骨折撑开器辅助开放复位接骨板内固定治疗跟骨结节明显上移的粉碎性跟骨骨折,可以简化操作,减少切口并发症,疗效满意。     

开窗直视下联合复位内固定治疗跟骨骨折

目的探讨跟骨外侧开窗直视下联合复位钢板内固定治疗跟骨骨折的临床疗效。方法对36例(38足)SandersⅡ~Ⅳ型跟骨骨折患者采用跟骨外侧切口,在跟骨外侧皮质开窗后直视下复位塌陷的关节面,尽量恢复Gissane角、Bhler角;对有骨缺损者行自体髂骨及异体骨植骨后钢板内固定。术后X线片上测量Bhler角、Gissane角及跟骨的长度、宽度、高度,与术前进行比较。按照Maryland足功能评分系统对患者术后功能进行评定。结果 31例患者(32足)获得随访,失访5例(6足),随访时间12~24个月。术后1年X线片示骨折处均达到骨性愈合。Bhler角:术前-3.6°±5.8°、术后29.4°±4.0°,差异有统计学意义(P0.05);Gissane角:术前88.9°±6.3°、术后115.9°±5.6°,差异有统计学意义(P0.05)。术后跟骨长度、宽度及结节部高度与术前比较差异均有统计学意义(P0.05)。采用Maryland足功能评分标准评估术后功能:优11足,良13足,可5足,差3足。结论跟骨外侧开窗直视下联合复位内固定治疗跟骨SandersⅡ、Ⅲ型骨折疗效满意,SandersⅣ型骨折疗效尚可。     

改良跗骨窦切口可塑形接骨板内固定治疗Sanders Ⅱ、Ⅲ型跟骨骨折疗效观察

目的观察改良跗骨窦切口可塑形接骨板内固定治疗Sanders Ⅱ、Ⅲ型跟骨骨折的临床疗效。方法回顾性分析自2015-01—2020-01诊治的34例Sanders Ⅱ、Ⅲ型跟骨骨折,采用改良跗骨窦切口(从外踝尖稍下1 cm至跟骰关节平面作一直切口长约5 cm,切口方向几乎与足底平行)复位骨折,于跟骨外侧骨膜下剥离后置入接骨板,采用模版定位法经皮置入导向器后钻孔并置入螺钉固定。结果 34例均获得随访,随访时间平均22.4(12～36)个月。术后12个月随访时所有患者均获得骨性愈合。术后1例出现皮肤浅表感染,应用抗生素并加强换药后痊愈。2例出现腓肠神经支配区麻木症状,经过4个月物理治疗和营养神经药物治疗后麻木症状消失。随访期间1例出现距下关节退行性改变。术后12个月踝与后足功能AOFAS评分:优26例,良5例,可3例。末次随访时所有患者跟骨B?hler角、Gissane角、跟骨高度、跟骨宽度较术前改善,B?hler角为(28.74±2.58)°,Gissane角为(118.69±4.13)°,跟骨高度为(38.58±1.87)mm,跟骨宽度为(30.12±1.54)mm。结论改良跗骨窦切口可塑形接骨板内固定治疗Sanders Ⅱ、Ⅲ型跟骨骨折疗效满意,切口并发症少,术后踝关节功能恢复良好,但是需要严格把握其适应证。     

跟骨外侧小切口联合撬拨复位中空钉内固定治疗Sanders Ⅱ型跟骨骨折的疗效分析

目的探讨跟骨外侧小切口联合撬拨复位中空钉内固定治疗Sanders Ⅱ型跟骨骨折的疗效。方法笔者自2012-08—2015-10采用跟骨外侧小切口联合撬拨复位中空钉内固定治疗10例Sanders Ⅱ型跟骨骨折,观察手术前后Bohler角、Gissane角改变,并按照Maryland足部功能评分标准观察术后足部功能情况。结果本组均获15~24(16.1±5.6)个月随访。均已经获骨性愈合并行内固定取出手术治疗。跟骨Bohler角由术前(9.6±5.3)°恢复至末次随访时(25.2±4.4)°,差异有统计学意义(t=-14.221,P0.001);跟骨Gissane角由术前(87.6±9.5)°恢复至末次随访时(126.3±6.6)°,差异有统计学意义(t=-23.731,P0.001)。末次随访疗效按Maryland足部功能评分系统进行术后功能评价,优9例,良1例。结论跟骨外侧小切口联合撬拨复位中空钉内固定治疗Sanders Ⅱ型跟骨骨折具有操作简单、创伤小、并发症少等优点,丰富了跟骨骨折微创治疗手术方案。     

足跟后方联合跗骨窦入路小切口切开复位接骨板内固定治疗跟骨闭合性骨折

目的探讨足跟后方联合跗骨窦入路小切口切开复位接骨板内固定治疗跟骨闭合性骨折的疗效。方法回顾性分析广东省云浮市人民医院骨科一区2016年2月至2019年2月采用足跟后方联合跗骨窦入路小切口切开复位接骨板内固定治疗的20例(25足)跟骨闭合性骨折患者。男16例,女4例;年龄16~60岁,平均41.8岁;骨折按Sanders分型:Ⅱ型3例,Ⅲ型15例,Ⅳ型2例。采用牵引、挤压、撬拨及跗骨窦窗直视下对骨折进行复位,足跟后方小切口置入接骨板,闭合拧入螺钉固定。术后观察骨折愈合情况及跟骨长度、宽度、高度、Böhler角、Gissane角及美国足踝外科协会(AOFAS)的踝-后足评分的改善情况。结果单足骨折手术时间45~70 min,平均64.5 min;术中单足透视3~6次,平均4.5次。术后1例1足局部出现约0.5 cm×0.3 cm的皮肤坏死,经换药处理后愈合,其余患者均未出现伤口并发症。所有患者术后随访6~36个月,平均17.3个月。骨折愈合,骨痂塑形好,后关节面平整,骨折愈合时间4~6个月。末次随访时跟骨长度(80.5±4.2)mm、宽度(44.8±5.2)mm、高度(44.4±3.0)mm、Böhler角25.0°±5.1°、Gissane角113.8°±8.6°较均术前[(79.4±4.5)mm、(50.5±6.3)mm、(40.0±4.5)mm、12.0°±13.8°、107.0°±13.3°]改善,差异有统计学意义(P<0.05)。足部功能恢复按AOFAS的踝-后足评分评价:优20足,良3足,可2足,优良率为92.0%。结论足跟后方联合跗骨窦入路小切口切开复位接骨板内固定治疗跟骨闭合性骨折,具有切口小、骨折复位好等优点,临床效果好。     

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.