颈椎前路融合术后假关节形成对疗效的影响

目的：观察颈椎前路减压融合术后假关节形成对神经功能和颈部症状的影响.方法：对109例颈椎前路减压融合术后患者进行平均11.1年的随访,常规拍摄颈椎屈伸侧位X线片,判断是否有假关节出现.采用JOA 17分法对手术前后的神经功能进行评定,观察术后患者的颈部症状并进行分级.对部分资料进行统计学分析.结果：109例患者的假关节发生率为26.61%（29/109）,单节段融合无假关节发生,而4节段融合的假关节发生率为36.36%.术后平均神经功能改善率为68.49%,颈部症状的发生率为35.78%.有假关节者与无假关节者比较,其神经功能改善率的差异有显著性意义（P＜0.05）,其颈部症状发生率相近.结论：假关节形成是颈椎前路手术后的常见远期并发症,其发生率与融合节段的多少有关.假关节形成可对术后远期神经功能恢复造成影响,但与患者术后颈部症状的发生无明显相关性.     

颈前路减压融合内固定治疗双节段脊髓型颈椎病术后轴性症状分析

目的:分析颈前路椎体次全切除融合内固定与颈前路双节段椎间盘摘除融合内固定治疗双节段脊髓型颈椎病术后轴性症状(AS)的发生情况。方法:2004年3月～2007年5月113例双节段脊髓型颈椎病患者分别行颈前路椎体次全切除融合内固定(A组,61例)和颈前路双节段椎间盘摘除融合内固定(B组,52例)。观察两组患者术前和末次随访时的JOA评分、融合节段高度和矢状面Cobb角,计算每组的神经功能改善率,统计每组术后颈部AS的发生率。结果:随访24～48个月,平均32.2个月。末次随访时A、B组神经功能改善率分别为(70.1±12.2)%、(63.5±4.7)%,无统计学差异(P0.05);融合节段高度变化值分别为-0.04±0.02cm、0.05±0.02cm,有统计学差异(P0.05);融合节段后凸率分别为34.4%、13.5%,有统计学差异(P0.05);颈部AS发生率分别为45.9%(28/61)、26.9%(14/52),有统计学差异(P0.05)。末次随访时融合节段高度降低者颈部AS发生率较高度增大者高(P0.05),A组中融合节段高度降低者的比例数明显大于B组(P0.05)。末次随访时,A组中融合节段明显后凸者的颈部AS发生率明显高于无后凸或轻度后凸者(P0.05),A组中融合节段明显后凸者的比例数明显大于B组(P0.05)。结论:颈前路减压融合内固定术后融合节段高度降低和明显后凸的患者AS发生率较高。与颈前路椎体次全切除融合内固定术相比,颈前路双节段椎间盘摘除融合内固定术治疗颈椎病在取得良好临床疗效的同时减少了术后颈部AS的发生。     

椎板切除融合治疗多节段脊髓型颈椎病伴节段不稳

目的评估后路颈椎板切除、植骨融合内固定治疗多节段脊髓型颈椎病伴节段不稳的疗效。方法对15例多节段颈椎病伴节段不稳的患者行后路颈椎板切除、减压、融合内固定术。分析手术前后JOA评分、轴性症状VAS评分、颈椎前凸角、颈椎曲度指数、脊髓向后漂移距离。结果 15例均获得随访,时间12~52个月。至末次随访,患者JOA评分、VAS评分、颈椎前凸角、颈椎曲度指数、脊髓向后漂移距离均较术前显著改善,差异均有统计学意义(P0.01)。1例术后切口感染,1例术后C5神经根麻痹,无脑脊液漏及内置物断裂发生。结论后路颈椎板切除、植骨融合内固定治疗多节段脊髓型颈椎病伴节段不稳能够改善神经功能,减少轴性症状发生,恢复颈椎生理性前凸。     

多节段脊髓型颈椎病伴后凸畸形不同入路方式的选择及疗效

目的 :探讨多节段脊髓型颈椎病伴后凸畸形的术式选择及疗效。方法 :回顾性分析2013年6月~2015年6月手术治疗的59例伴有后凸畸形的多节段脊髓型颈椎病患者的临床及影像学资料,其中55例获得随访。依据颈椎后凸Cobb角大小并结合影像学特点,分为轻度后凸(Cobb角5°但20°)、中度后凸(Cobb角20°~40°)和重度后凸(Cobb角40°)3组。依据致压因素和颈椎后凸角度采用前路或者后路手术治疗,其中轻度组29例,前路手术11例,后路手术18例;中度组18例,前路手术14例,后路手术4例;重度组8例,均行前路减压重建手术。比较各组内前路和后路手术时间、术中出血量、后凸矫正率及神经功能改善率的差异,比较组间前路手术后凸矫正率及神经功能改善率,比较轻度后凸组与中度后凸组间后路手术神经功能改善率。结果:轻度组和中度组中前、后路手术时间无统计学差异(P0.05),术中出血量后路手术大于前路手术(P0.05)。重度组1例术后6h发生颈部血肿,中度组1例术后12h发生硬膜外血肿;喉返神经牵拉伤4例,其中轻度组1例,中度组1例,重度组2例;11例出现术后四肢麻木、无力症状加重,轻度组2例,中度组5例,重度组4例;9例术后1周左右出现颈肩部疼痛症状加重,轻度组4例,中度组3例,重度组2例。3组间随访时间无统计学差异(P0.05)。轻度组中,末次随访时前路手术后凸畸形矫正率高于后路手术(P0.05),JOA评分改善率前路手术与后路手术无统计学差异(P0.05)。中度组中,末次随访时后凸畸形矫正率前路手术高于后路手术(P0.05),JOA评分改善率前、后路手术无统计学差异(P0.05)。末次随访时,轻度组的前路手术后凸畸形矫正率为223.1%,明显高于中度组(135.1%)与重度组(120.4%)(P0.05)。末次随访时,3组间前路手术JOA评分改善率无统计学差异(P0.05),轻度组与中度组后路手术JOA评分改善率无统计学差异(P0.05)。结论:伴有轻、中度后凸畸形的多节段脊髓型颈椎病,手术入路依据脊髓受压情况而定,后凸畸形不影响神经功能的改善;而重度后凸畸形,则应当兼顾减压和矫形,前路手术可同时达到减压和矫形的目的,获得较为满意的神经功能改善。     

颈椎前路融合术后颈部运动功能的评价

目的观察颈椎前路融合术后相邻节段的退变情况和颈部症状的关系,以及颈椎各节段和整体活动度在手术前后的变化。方法对66例颈椎前路融合术后的患者随访1-16年,平均10.5年,观察融合相邻节段在过伸、过屈侧位X线片上的活动度和成角、滑移程度,及其和颈部症状之间的关系。将其中59例患者的手术前后整体颈椎和未融合节段的活动度进行对比,寻找其变化规律。结果在随访期内观察到的相邻节段不稳定发生率为72.7％,有明显颈部症状者占40.9％。融合相邻节段不稳定的患者中有明显颈部症状者占48.0％,相邻节段稳定者中出现明显颈部症状者占18.8％,其差异有显著性意义(P<0.05),轻度不稳定和显著不稳定者发生明显颈部症状的差异无显著性意义(P>0.1)。患者手术后整体颈椎的活动度明显变小(P<0.001),相邻节段活动度显著增大(P<0.01),非相邻节段活动度无明显变化(P>0.05)。结论颈椎前路融合术后多数患者将出现相邻节段不稳定,但是多数患者颈部无明显症状,相邻节段不稳定是颈部症状发生的原因之一。     

颈椎前路椎间盘切除、植骨融合内固定术治疗脊髓型颈椎病术后轴性症状的前瞻性研究

【摘要】 目的：前瞻性分析若干临床因素与颈前路椎间盘切除、植骨融合内固定治疗脊髓型颈椎病术后颈部轴性症状发生的相关性。方法：2011年5月～2011年9月间接受由同一专业组术者完成的颈椎前路椎间盘切除、椎体间植骨融合、钛板内固定术患者107例,术前均无颈部疼痛、僵硬等轴性症状,均于术后3个月在门诊复查。采用日本骨科协会改良17分评分法（modified Japanese Orthopaedics Association,mJOA）改善率评价患者术后神经功能恢复情况,观察术后新出现的颈部轴性症状的发生率并使用视觉模拟评分法（visual analogue scale, VAS）评价轴性症状的程度。收集所有患者的年龄、性别、术前/术后手术节段曲度、手术节段椎间撑开高度、植骨融合情况、术后项背肌功能锻练及术后围领佩戴时间等八项临床相关因素,使用Logistic回归分析上述临床因素对术后出现颈部轴性症状的影响。使用独立样本t检验分析轴性症状与术后神经功能改善的关系。结果：本组107例患者中男性56例,女性51例,年龄29~80岁,平均52.2岁。手术节段：单节段49例（45.8%）,双节段47例（43.9%）,三节段11例（10.3%）。本组患者术后3个月复查时新出现的颈部轴性症状发生率为26.2%（28/107）,VAS平均为4分（2~8分）。所研究的八项临床相关因素中,术后项背肌功能锻练（P=0.0003,OR=185.6）、手术节段术前曲度（P=0.003,OR=8.1）和植骨融合情况（P=0.016,OR=37.1）与术后发生颈部轴性症状有相关性。术后出现新发轴性症状患者术后mJOA评分改善率为58.6%±32.8%,未发生轴性症状患者术后mJOA改善率为65.5%±30.6%,两组结果无统计学差异（P=0.317）。结论：颈椎前路术后新发颈部轴性症状并不少见。术后项背肌功能锻炼差、术前手术节段后凸和无植骨融合迹象与术后新发轴性症状有关。     

节段型严重颈椎后纵韧带骨化症前路、后路手术的疗效比较与选择策略

 目的 探讨前路和后路手术治疗节段型严重颈椎后纵韧带骨化症的疗效与选择策略。方法 2007年1月至2011年5月,手术治疗59例节段型严重颈椎后纵韧带骨化症患者,男41例,女18例;年龄43～73岁,平均55.7岁。24例行前路椎体次全切减压植骨融合内固定术,35例行后路全椎板减压侧块螺钉内固定术。比较两组患者的手术时间、出血量、整体和节段曲度变化、并发症等情况;采用日本骨科协会评分(Japanese Orthopaedic Association Scores,JOA)评估手术前后的神经功能并计算改善率。结果 所有患者随访12～18个月,平均15.4个月。前路手术组患者JOA评分术前平均为(7.33±1.09)分,末次随访时平均为(13.63±0.82)分,改善率为65.16%±7.50%;后路手术组患者JOA评分术前平均为(7.20±1.05)分,末次随访时平均为(12.23±1.11)分,改善率为51.46%±9.64%,两组间差异有统计学意义。手术部位的节段曲度术后即刻均较术前明显增加,前路手术组为5.38°±1.14°,后路手术组为3.89°±1.65°,差异有统计学意义。末次随访时颈部轴性症状发生率前路手术组为20.83%,后路手术组为51.43%,差异有统计学意义。结论 对于骨化范围在3个节段以内的严重后纵韧带骨化症患者,前路手术能直接去除压迫,神经功能恢复良好,并有效地恢复颈椎曲度,术后轴性症状发生率低;后路手术在减压同时应用侧块螺钉内固定,能较好地维持减压节段的曲度。     

颈椎前路术后融合节段椎间隙高度变化与轴性症状的相关性研究

[目的]探讨颈椎前路术后融合节段的椎间隙高度变化与颈部轴性症状发生率的关系.[方法]对122例颈椎前路融合手术患者进行2～5年随访,平均3.9年,分别于手术前、术后3个月和术后2年随访时拍摄颈椎中立侧位X线片,测量融合节段椎间隙高度,计算融合节段椎间隙高度的变化值,依据患者术后椎间隙高度变化情况将全部样本分为三组,对三组患者术后轴性症状发生率进行观察、分类及统计学分析.[结果]三组颈椎轴性症状发生率分别为54.55%、25.84%和45.45%,经过统计学分析,A组:B组x2值=7.18,P＜0.0125;B组:C组x2值=6.81,P＜0.0125,差异有统计学意义.A组:C组x2值=3.19,P＞0.0125,差异无统计学意义.[结论]颈椎前路术后融合节段椎间隙高度的变化与颈部轴性症状的发生率有显著相关性.     

颈椎前路融合节段相邻椎间盘压力与轴性症状关系初探

目的分析在生理前凸获得有效重建的颈椎前路减压融合术中,融合节段相邻椎间盘压力变化与颈椎术后轴性症状发生的关系。方法行前路单椎体次全切除减压内固定手术治疗颈椎伤病42例,术中测量融合节段相邻椎间盘内压力,计算颈椎融合前后压力差。以D值法(C4椎体后下缘到齿状突后上缘与C7椎体后下缘连线的垂直距离,正值表示前凸)测量手术前后颈椎曲度变化,同时观察术后轴性症状的发生。分析颈椎曲度及相邻椎间盘压力变化与术后发生轴性症状的相关性。结果全部病例术后D值均为正值,与术前差异有显著性(P<0.05)。术后颈椎曲度变化与轴性症状发生无相关性(P>0.05),而相邻椎间盘压力变化与轴性症状发生有显著相关性(P<0.05)。术后发生轴性症状组(12例)相邻椎间盘压力差与无轴性症状组(30例)差异有显著性(P<0.05)。结论在生理前凸获得有效重建的颈椎前路减压融合术中,融合节段相邻椎间盘压力变化与术后轴性症状发生的关系密切。术中相邻椎间盘压力监测有助于准确掌握撑开程度,减少术后轴性症状的发生。     

颈前路手术治疗3节段脊髓型颈椎病

目的分析颈前路减压融合手术治疗3节段脊髓型颈椎病的临床疗效。方法对124例3节段脊髓型颈椎病患者行颈前路手术治疗,78例行颈前路椎间盘切除减压融合术(ACDF),46例行颈前路椎体次全切除减压融合术(ACCF)。评估术后JOA评分及其改善率、植骨融合情况以及颈椎曲度。结果患者均获得随访,时间:ACDF组13~54(36.7±15.1)个月,ACCF组14~53(33.6±18.7)个月。两组患者术后JOA评分及颈椎Cobb角均较术前显著提高及恢复,差异均有统计学意义(P0.05)。ACDF组在手术时间、术中出血量及颈椎生理曲度恢复程度方面均优于ACCF组,且并发症发生率更低(P0.05)。两组术后JOA评分及其改善率、植骨融合率比较差异无统计学意义(P0.05)。结论 ACDF与ACCF治疗3节段脊髓型颈椎病均可达到满意的神经功能恢复;ACDF治疗后颈椎生理曲度恢复较好,且并发症发生率较低。     

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.     

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.