锚钉固定位置与角度对肩关节前关节囊修复效果影响

目的探讨不同锚钉位置及角度对关节镜治疗复发性肩关节前向不稳临床疗效的影响。 方法回顾性分析85例于2018年1月至12月因复发性肩关节前向不稳在南部战区总医院接受肩关节镜手术治疗的患者排除严重骨缺损、翻修等其他损伤。使用术后肩关节CT测量锚钉位置及插入角度，采用视觉模拟评分系统(VAS评分)及Rowe评分系统对患者术后关节疼痛程度、稳定性、活动度及功能进行综合评价。不同锚钉位置及角度与VAS评分及Rowe评分的关系使用独立样本t检验分析。 结果在85例患者中，有57例患者的所有锚钉均在肩胛盂关节面上，28例患者的锚钉部分在肩胛盂关节面上，部分在肩胛盂边缘。两组的比较中，VAS评分差异无统计学意义(t ＝－0.829，P>0.05)；所有锚钉均在肩胛盂关节面上的患者Rowe评分较高(t＝－4.072，P<0.05)。通过术后Rowe评定分级对锚钉打入角度的反向比较中，2点、3点、4点和5点钟4个位点对应锚钉角度之间的比较均无统计学差异(t＝0.312、0.885、0.775、0.934，均为P>0.05)。 结论肩关节镜下缝合锚钉在合理插入角度范围内固定于肩胛盂边缘稍内侧的关节面上可以使复发性肩关节前向不稳的患者获得更好的近期疗效，而远期疗效需要进一步深入研究。     

双带线锚钉重建喙锁韧带治疗Tossy Ⅲ型肩锁关节脱位的CT测量及临床应用

目的 :通过对喙突的冠状面CT测量探讨双枚带线锚钉重建喙锁韧带治疗肩锁关节脱位的可行性和可靠性,为临床治疗肩锁关节脱位提供一种新的手术方法。方法:选18~50岁健康成年人,男女各30例,进行肩关节多层螺旋CT平扫。对喙突中部冠状面的宽度、厚度及外倾20°斜角线厚度等做CT解剖学测量。临床应用12例,均为TossyⅢ型肩锁关节脱位。结果 :喙突中部的左右宽度:男性左侧(17.65±1.82)mm,右侧(17.67±1.80)mm;女性左侧(16.55±1.78)mm,右侧(16.52±1.74)mm。垂直厚度:男性左侧(13.11±2.11)mm,右侧(13.16±2.09)mm;女性左侧(12.79±2.21)mm,右侧(12.76±2.19)mm。外倾20°斜角线厚度:男性左侧(16.32±1.74)mm,右侧(16.30±1.69)mm;女性左侧(15.68±1.44)mm,右侧(15.67±1.43)mm。临床应用12例,均按外倾20°置入锚钉,术后复查X线片示锚钉均位于喙突骨质内,未见骨质劈裂。结论:喙突可以接受直径5 mm的2枚带线锚钉,外倾20°置入锚钉可完全纳入骨质内,临床效果满意。     

6点位锚钉置入修复Bankart损伤的手术技巧

[目的]介绍关节镜下6点钟位锚钉置入盂唇缝合治疗肩关节前方不稳的手术技巧和临床疗效。[方法] 2018年1月1日—2021年1月1日,对51例成人肩关节脱位采用四入路技术进行关节镜下后方Remplissage修复与前方Bankart修复术。建立前上入路尽可能偏上,前下入路用止血钳测试能否到达6点位,2个入路不可太近。松解前方盂唇复合体至6点甚至后方7点位,盂缘表面去软骨5 mm。置入6点位锚钉,尽量全层修复盂唇复位体。[结果]所有患者均顺利完成手术,无严重术中并发症,随访12～24个月。所有患者均未再次出现肩关节脱位。末次随访时ASES评分、Constant-Murley评分和Rowe均较术前显著改善（P<0.05）。术后常规复查三维CT提示锚钉位置良好。[结论]关节镜下6点钟位锚钉置入盂唇缝合治疗盂肱关节不稳手术效果良好。手术的成功有赖于术前严格把握适应证,术中关节镜下操作技术的熟练程度。     

退变性腰椎侧凸患者腹主动脉与腰椎椎体相对位置的影像学测量

目的:探讨退变性腰椎侧凸(degenerative lumbar scoliosis,DLS)患者腰椎左侧凸和右侧凸情况下,腹主动脉与腰椎椎体的解剖关系。方法:回顾性分析我院2015年1月～2018年6月142例DLS患者和132例无脊柱侧凸的正常人群(对照组),DLS患者包含80例左侧凸患者(左侧凸组)和62例右侧凸患者(右侧凸组),观察对象均处于矢状位平衡,两组在性别、年龄和体重指数(body mass index,BMI)上与对照组匹配。通过X线片测量DLS患者腰椎侧凸方向、Cobb角、顶椎位置及冠状位偏移距离;通过MRI T1加权像建立笛卡尔坐标系,测量主动脉-椎体角度(α)、旋转角度(γ)、主动脉-椎体距离(d)及主动脉后壁-椎体前缘间隙(Int)。α、γ、d和Int分别在左侧凸组与对照组、右侧凸组与对照组的组间对比采用独立样本t检验;Cobb角及冠状位偏移距离与α、γ、d和Int的相关性检验采用Pearson相关分析。结果:左侧凸组Cobb角为23.7°±12.7°(10.4°～42.5°),冠状位偏移距离为45.2±10.7mm(25.5～77.7mm);右侧凸组Cobb角为20.8°±10.4°(11.0°～48.4°),冠状位偏移距离为47.8±15.1mm(25.4～77.5mm),两侧凸组的顶椎分布(P=0.280)、Cobb角(P=0.311)和冠状位偏移距离(P=0.394)均无统计学差异。对照组α平均为-2.96°±6.40°,从T12～L4逐渐减小,而左侧凸组α(-2.57°±6.14°)无该规律,两组α比较无统计学差异(P=0.554);左侧凸组γ平均为5.57°±5.32°;左侧凸组d(4.62±0.57cm)自T12～L4逐渐增大,且与对照组(4.44±0.43cm)比较有统计学差异(P0.001);左侧凸组Int与对照组比较无统计学差异(P=0.832),即相对于正常人群,DLS左侧凸患者腹主动脉相对于椎体角度无改变,但距离稍远离左侧椎体。右侧凸组α(-3.41°±9.44°)自T12～L4逐渐减小,与对照组比较无统计学差异(P=0.762);γ为-9.02°±6.71°;d为4.54±1.84cm,与对照组比较无统计学差异(P=0.530);Int与对照组比较无统计学差异(P=0.807),即相对于对照组,DLS右侧凸患者腹主动脉与椎体的角度和距离无明显变化。Pearson相关分析显示,左侧凸组和右侧凸组Cobb角和冠状位偏倚距离与γ均存在相关性(均为P0.001),而与α、d和Int无明确相关性。结论:DLS右侧凸患者腹主动脉与椎体相对位置维持正常的解剖关系,左侧凸患者腹主动脉稍远离左侧椎弓根。DLS患者腹主动脉与腰椎相对解剖关系较正常人变化不大,但腰椎手术尤其是侧凸矫形过程中仍需要警惕腹主动脉损伤。     

标杆型3D打印导板辅助寰枢椎椎弓根置钉准确度分析

目的探讨标杆型3D打印导板辅助寰枢椎椎弓根置钉的可行性,并进行置钉准确度分析。方法 2014年6月—2015年8月,本院收治寰枢椎脱位患者21例,男12例,女9例;年龄12~54岁,平均42.6岁。术前使用Mimics 17.0软件和3-matic 9.0软件为每例患者制作标杆型3D打印导板,术中使用标杆型3D打印导板辅助寰枢椎椎弓根置钉,术后患者行颈椎CT平扫。在Mimics 17.0软件中,将手术前后的寰枢椎模型及螺钉配对拟合,调整空间坐标轴,测量并比较术前预设钉道与术后实际钉道的内倾角、头倾角、进钉点坐标。结果 21例患者手术顺利,手术时间(193±51)min,术中出血量(384±127)m L。共置入寰椎椎弓根螺钉30枚,枢椎椎弓根螺钉42枚。除2枚寰椎椎弓根螺钉侵入椎管≤2 mm外,其他螺钉均位于椎弓根骨皮质内。寰椎左右侧预设最佳钉道内倾角度分别为9.4°±1.8°、9.8°±1.6°,实际钉道内倾角度分别为8.7°±1.6°、10.6°±2.2°;左右侧预设最佳钉道头倾角度分别为8.9°±2.5°、8.8°±2.3°,实际钉道头倾角度分别为9.3°±2.9°、9.4°±3.5°。枢椎左右侧预设最佳钉道内倾角度分别为21.9°±6.6°、22.4°±6.9°,左右侧实际钉道内倾角度分别为24.1°±6.3°、20.8°±6.4°;左右侧预设最佳钉道头倾角度分别为23.7°±7.3°、24.2°±7.2°,左右侧实际钉道头倾角度分别为22.1°±7.9°、22.3°±7.6°。寰枢椎术后实际钉道与术前预设最佳钉道的内倾角、头倾角、进钉点坐标差异均无统计学意义(P0.05)。结论标杆型3D打印导板辅助寰枢椎椎弓根置钉方向可调整性好,置钉准确度较高,为临床寰枢椎置钉提供了一种新的方法。     

虚拟手术系统支持下置入寰椎侧块螺钉的实验研究

目的:建立虚拟手术系统支持下经寰椎侧块内固定的标准体系及操作流程,探讨在其支持下置入寰椎侧块螺钉的可行性及准确性。方法:选取8例成年无破损和畸形的寰椎(C1)防腐头颈标本,CT扫描后,数据导入虚拟手术系统进行三维重建和螺旋CT多平面重建(MPR),测量寰椎侧块数据;选择侧块与后弓根部下方交界区和横突孔的内侧缘与寰椎后弓内侧壁中点为进钉点,分别测量横突孔的内侧缘与寰椎后弓内侧壁的距离(L1),进钉点与侧块前缘最高点的距离(L2),进钉点与侧块前缘的垂直距离(L3),进钉点的垂线与寰椎侧块上缘切线的角度(α),进钉点垂线与横突孔内侧缘切线的角度(β),进钉点垂线与侧块内侧缘切线的角度(γ),并计算内斜角度[δ=(β+γ)/2-β]。左右两侧均测量3次,取其均值,进行统计学分析。根据虚拟手术系统测量结果,在标本上模拟手术置入寰椎侧块螺钉,然后虚拟手术系统进行重建,测量置钉准确性。结果:建立了虚拟手术系统手术流程,虚拟手术系统测量寰椎侧块相关参数L1左侧为9.82±0.76mm,右侧为9.16±0.85mm;L2左侧为21.76±1.36mm,右侧为21.50±1.02mm;L3左侧为17.78±1.67mm,右侧为18.22±1.60mm;α左侧为36.78°±1.23°,右侧为35.78°±2.40°;β左侧为18.84°±1.80°,右侧为18.40°±1.71°;γ左侧为31.49°±0.60°,右侧为30.46°±1.56°;δ左侧为6.32°±1.08°,右侧为6.25°±1.11°;经统计学分析,左右侧测量值均无统计学差异(P>0.05)。尸体标本置钉16枚,全部位于侧块内,未伤及毗邻组织。结论:虚拟手术系统支持下置入寰枢椎侧块螺钉可行且准确性高。     

关节镜下带线锚钉垂直褥式缝合修复Bankart损伤

目的介绍关节镜下带线锚钉垂直褥式缝合修复Bankart损伤技术,并评价其临床疗效。方法关节镜下带线锚钉垂直褥式缝合修复Bankart损伤技术操作步骤：于肩胛盂缘3点和5点钟位置分别植入2枚带线锚钉,分别在盂唇2点、4点和6点位置将盂唇韧带复合体进行垂直褥式缝合,并将其前下方关节囊向上转移。2004年4月至2006年8月收治的9例盂肱关节前向不稳定患者均无严重的肩胛盂骨性缺损,手术时平均年龄28岁（21—46岁）。采用Rowe肩关节修正评分进行临床随访,平均随访时间14个月（6—26个月）。Rowe肩关节修正评分术前（40±16）分。结果手术时间平均为51min（40—75min）。术后Rowe肩关节修正评分上升至（92±19）分（75—94分）。随访期间无复发,也未发生并发症,0°外展时外旋平均减少5°,90°外展时外旋平均减少3°。结论关节镜下带线锚钉垂直褥式缝合修复Bankart损伤治疗盂肱关节前下不稳定手术技术相对简单、手术时间短、近期临床效果较好。     

应用MIMICS软件肩胛盂数字解剖研究

[目的]应用MIMICS软件测量肩胛盂形态参数,比较左右侧和男女两性间的差异。[方法]对2022年8月—2023年7月84例正常成人双侧肩关节CT扫描资料进行分析。研究对象男45例,女39例,年龄18～86岁,平均(53.8±17.9)岁。将CT数据导入MIMICS软件行三维重建,拟合出肩胛盂凹曲面、肩胛盂走行平面、肩胛骨走行平面,测量肩胛盂的高度、宽度、高宽比、上下深度、前后深度、深度比、凹曲面面积(盂表面积)、倾斜角。[结果]45例成年男性和39例女性左右两侧肩胛盂的高度、宽度、高宽比、上下深度、前后深度、上下与前后深度比(深度比)、盂表面积和倾斜角的差异均无统计学意义(P>0.05)。左侧男性肩胛盂的高度[(37.2±2.4) mm vs (32.6±2.4) mm, P<0.001]、宽度[(28.5±2.8) mm vs (23.2±2.3) mm, P<0.001]、上下深度[(3.6±0.9) mm vs (3.3±1.0) mm, P=0.013]、前后深度[(2.0±0.7) mm vs (1.7±0.8) mm, P=0.036]、盂表面积[(82...     

脊柱侧弯椎弓根螺钉和主动脉相对位置的研究

[摘要]目的：评估脊柱侧弯患者置入右侧椎弓根螺钉时主动脉的安全性。方法：评估137名脊柱侧弯患者,患者的平均年龄14岁。平均Cobb角（68．0±17．0）°。我们以CT数据评估主动脉相对于T3-L4节段以及自不同于理想钉道方向模拟置入的右侧椎弓根螺钉的位置。     

椎动脉的解剖研究及在上颈椎椎弓根置钉中的应用

目的：测量上颈椎椎弓根与椎动脉的位置关系,提高上颈椎椎弓根螺钉置入的安全性。方法：成人头颈部尸体标本6具（12侧）,解剖椎动脉,测量寰椎椎弓根螺钉进钉点处椎动脉下缘距椎动脉沟底部的距离,枢椎横突孔內缘与椎动脉內缘的距离,横突孔内椎动脉的外径,记录数据并进行统计学处理。结果：寰椎椎弓根螺钉进钉点处椎动脉下缘距椎动脉沟底部的距离为左侧（1.96±0.72）mm,右侧（1.99±0.61）mm,枢椎横突孔內缘与椎动脉外缘的距离为左侧（2.23±0.43）mm,右侧（2.30±0.39）mm,横突孔内椎动脉的外径为左侧（3.03±0.48）mm,右侧（2.98±0.75）mm。结论：除了椎动脉高跨病例外,正确置入上颈椎椎弓根螺钉无损伤椎动脉之虞,椎弓根钉置入时应尽量个体化。     

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.     

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.     

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.     

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.     

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.