球囊扩张与Sky扩张椎体后凸成形术的对比研究

[目的]探讨球囊扩张与Sky扩张后凸成形术对椎体压缩骨折复位作用的差异,并评价后凸成形术的临床疗效.[方法]自2005年10月～2007年10月,对19例骨质疏松性椎体压缩骨折患者分别施行球囊扩张和Sky扩张椎体后凸成形术,将其中19例压缩骨折患者随机分为两组(A组为球囊组9例,B组为Sky组10例,分别施行两种手术方式),分别测量手术前后椎体高度和Cobb's角,行VAS评分,观察术后并发症,比较术后两组疗效的差异.[结果]所有患者术后疼痛明显减轻或消失,两组椎体高度与术前相比均有显著恢复,P<0.001,有显著统计学意义.其中A组术后椎体前缘、中央高度恢复率分别为20.82%±12.43%、12.51%±10.53%,Cobb's角术后恢复9.64%±8.27%,VAS评分术后缓解6.28±1.2分;B组术后椎体前缘、中央高度恢复率分别为21.93%±13.39%、13.02%±11.68%,Cobb's角术后恢复10.33%±9.28%,VAS评分术后缓解6.46±1.1分,两组比较P>0.05,差别无统计意义.[结论]无论采用球囊扩张椎体后凸成形术,还是Sky扩张椎体后凸成形术,均可有效恢复压缩椎体的高度,纠正后凸畸形,迅速缓解疼痛,两者疗效无明显差异性.     

单球囊与双球囊后凸成形术对椎体复位作用的研究

目的探讨单球囊与双球囊后凸成形术对椎体压缩骨折复位作用的差异,评价后凸成形术的临床疗效。方法对2000年5月～2004年5月应用球囊扩张后凸成形术(KP)施行椎体复位的58例胸腰椎椎体压缩性骨折(VCFs)患者(90个椎体)的临床资料进行了回顾性分析。58例患者90个椎体分为单球囊组(28个椎体)和双球囊组(62个椎体),两组均经双侧椎弓根穿刺,扩张后灌注骨水泥,分别采用单球囊双侧交替扩张和双球囊双侧同时扩张的方法。分别测量术前术后椎体高度和Cobb角,比较术前术后及两组之间的差异。结果患者术后疼痛均明显减轻或消失。椎体高度平均恢复率726%(229～100%);Cobb角由术前179°(31°～316°)矫正至术后96°(06°～282°),平均矫正87°(03°～272°),术前、术后相比差异有极显著性意义(P<0001)。单球囊组和双球囊组术后椎体高度平均恢复率分别为776%(553%～100%)和643%(229%～100%),术后平均矫正Cobb角分别为99°(03°～272°)和86°(06°～198°),两组相比差异无显著性意义(P>005)。结论后凸成形术可有效缓解椎体压缩骨折患者的疼痛,恢复椎体高度,改善后凸畸形;单球囊与双球囊后凸成形术同样能使压缩骨折的椎体获到较好复位。     

手法复位在骨质疏松性椎体压缩骨折经皮椎体后凸成形术中的应用

[目的]评价手法复位在骨质疏松性椎体压缩骨折经皮椎体后凸成形术中的临床应用.[方法] 2009年1月～2012年6月行经皮椎体后凸成形术的骨质疏松性椎体压缩骨折患者65例随机分为治疗组和对照组,分析比较两组骨水泥外漏发生率及术后2d、术后3个月、末次随访时疼痛恢复情况、椎体高度和脊柱后凸角(Cobb角)的变化.[结果]所有患者均获得6 ～21个月随访,平均11.3个月.于术后2 d、术后3个月及末次随访时进行测量,治疗组VAS评分较术前分别降低(4.32±1.01)、(4.97±0.70)、(5.45±1.95),椎体高度分别增加(6±1.12) mm、(6+1.12) mm、(5.97±1.13) mm,后凸cobb角分别减小(12.48+2.06)°、(12.35±1.96)°、(12.29±1.90)°,有6个椎体发生骨水泥外漏,对照组VAS评分较术前分别降低(4.74±1.24)、(5.21±1.01)、(5.38±0.89),椎体高度分别增加(3.18±0.87) mm、(3.18±0.87) mm、(3.15±O.86) mm,后凸Cobb角分别减小(5.85±1.81)°、(5.59±1.73)°、(5.29±1.45)°,有8个椎体发生骨水泥外漏.术后2d、术后3个月及末次随访时治疗组椎体高度恢复及脊柱后凸畸形矫正均明显优于对照组(P＜0.01),VAS评分变化及骨水泥泄漏率差异无统计学意义(P＞0.05).[结论]手法复位应用于骨质疏松性椎体压缩骨折经皮椎体后凸成形术是安全有效的,可以更好的恢复椎体高度和纠正脊柱后凸畸形,不增加骨水泥泄露的发生率,也不影响术后疼痛的改善.     

脊柱压缩骨折微创治疗的初步报告

目的探讨椎体成形术及椎体后凸成形术治疗脊柱压缩骨折(vertebral compression fractures,VCF)的初步疗效和安全性. 方法 2000年5月～2002年10月分别采用椎体成形术(vertebroplasty,VP)及椎体后凸成形术(kyphoplasty,KP)治疗脊柱压缩骨折43例69椎,分别为椎体后壁完整的疼痛性骨质疏松性压缩骨折及椎体血管瘤导致的椎体压缩骨折.先经双侧椎弓根或椎弓根旁置入导针或可扩张球囊使骨折塌陷椎体复位,然后骨水泥充填椎体,观察术后症状改善及骨折复位情况,分析并发症. 结果 43例手术均顺利,疼痛于术后48 h内均明显缓解.VP组椎体高度无明显改变,KP组骨折椎体前缘和中部高度的丢失分别由术前的(13.6±2.3)mm和(9.2±1.4)mm减少至(4.7±1.5)mm和(3.4±1.1)mm(t=2.85,3.27;P<0.01),后凸畸形Cobb角由术前的24.4°±5.2°矫正至9.5°±4.7°(t=3.21,P<0.01).1例一侧术中穿刺管内出现脑脊液,该侧当即停止手术.未发现其他严重并发症.随访3～28个月,平均13个月,SF-36评分由术前(187.5±10.3)分恢复至术后(376.4±15.9)分(t=4.36,P<0.01). 结论椎体成形术及椎体后凸成形术可迅速、有效缓解疼痛,改善功能,椎体后凸成形术可更有效地恢复脊柱序列.     

椎体后凸成形术与椎体成形术生物力学比较

目的比较椎体后凸成形术（KP）与椎体成形术（VP）对骨质疏松性椎体压缩骨折（OVCF）椎体力学性能的影响。方法5具尸体取20个胸腰段骨质疏松单椎体标本,按配对设计,分配为球囊扩张椎体后凸成形术组（KP组）和椎体成形术组（VP组）。经轴向加载压缩25%,制成椎体压缩骨折,记录制成骨折时的最大载荷及刚度数据。KP组将椎体压缩骨折标本行球囊扩张椎体后凸成形术;VP组将椎体压缩骨折标本行椎体成形术。然后将骨水泥强化治疗的椎体再次经万能力学试验机轴向加载,记录治疗后最大载荷及刚度数据。结果KP组和VP组骨折治疗后椎体最大载荷均分别明显高于骨折前（P〈0.01）,而椎体刚度差异无统计学意义（P〉0.05）。KP组与VP组间比较治疗后椎体最大载荷差异无统计学意义（P〉0.05）,椎体刚度差异无统计学意义（P〉0.05）。结论KP和VP均可明显增加OVCF椎体的抗压强度和恢复刚度。     

防腐标本椎体成形术与椎体后凸成形术骨水泥渗漏及其相关因素的研究

目的 探讨防腐标本椎体成形术与椎体后凸成形术骨水泥渗漏率的差异、渗漏的类型及其原因.方法 选用40个防腐标本椎体,将其制备成压缩骨折模型.其中20个防腐标本椎体行椎体成形术(A组),另外20个椎体行椎体后凸成形术(B组).对椎体骨水泥的渗漏及分布进行测定、记录,并对数据行统计学分析.通过CT对骨水泥的渗漏及分布进行评估.结果 A组8个椎体(40％)、B组3个椎体(15％)出现骨水泥渗漏;采用x2检验对椎体渗漏率进行比较,差异无统计学意义(P＞0.05),但提示椎体后凸成形术术后骨水泥渗漏率更低.结论 防腐标本椎体后凸成形术比椎体成形术渗漏率更低,安全性更高,但应在术中严密监测球囊撑开的压力及注入骨水泥的分布.此外,应用高黏度骨水泥能更有效的减少骨水泥渗漏.     

球囊与扩张矫形器辅助的椎体后凸成形术治疗骨质疏松性椎体压缩骨折的比较

[目的]比较球囊辅助椎体后凸成形术(balloon kyphoplasty,BKP)和扩张矫形器辅助椎体后凸成形术(expander kyphoplasty,EKP)在治疗骨质疏松性椎体压缩骨折(osteoporosis vertebral compression fractures,OVCFs)的临床疗效差异。[方法]2014年1月~2015年1月,120例骨质疏松症合并胸腰椎单节椎体压缩性骨折患者进行椎体成形术治疗,根据手术使用器材不同,分为EKP组(60例)和BKP组(60例),分析两组患者临床资料,包括性别、年龄、手术时间,观察骨水泥注入量、测量椎体后凸角度(Cobb角法)及并发症情况,术前、术后1 d,术后1、3、6个月、1年分别采用VAS(视觉模拟评分法)评分系统评估患者疼痛情况,椎体前缘高度压缩率恢复值及后凸角度改善情况比较两组的临床疗效。[结果]两组患者性别、年龄、手术时间、术后随访时间差异无统计学意义(P>0.05)。BKP组骨水泥注入量较EKP组大(5.64±0.57)ml vs.(4.28±0.51)ml(P<0.05)。PKP组椎体前缘高度压缩率改善率较EKP组明显(10.87±2.32)%vs.(9.48±1.43)%(P<0.05)。VAS评分改善、Cobb角改善情况、骨水泥渗漏率两组间差异无统计学意义(P>0.05)。[结论]椎体后凸成形术不同辅助方式手术治疗骨质疏松压缩骨折均能获得良好的临床疗效,EKP在恢复椎体前缘高度的作用上稍逊,但因其价格相对低廉,在椎体高度丢失较小、仅需缓解疼痛及强化椎体的患者可考虑使用。     

液压输送式椎体成形术与扩张球囊椎体后凸成形术治疗单节段骨质疏松性脊柱骨折的疗效比较

[目的]对比分析评估新型液压输送式椎体成形术与扩张球囊椎体后凸成形两种术式在治疗单节段骨质疏松性脊柱骨折中疗效的差异。[方法]对本院骨科一区2012年5月~2013年9月间符合条件的64例单节段骨质疏松性脊柱骨折患者术前随机分为液压输送式椎体成形(A组,34例)以及扩张球囊椎体成形(B组,30例)两组,分别进行相应的手术术式处理。术后随访1年,通过VAS评分、ODI评分评估患者手术前后症状改善、功能恢复情况;通过骨水泥渗漏与否、椎体高度恢复程度、骨水泥弥散情况等进一步分析比较两种不同椎体成形术式治疗脊柱骨折疗效及预后可能产生的差异。[结果]两组患者术后VAS评分及ODI评分均较术前明显改善,术后1年时椎体高度恢复率A、B两组分别为(27.84±2.12)%和(29.82±5.13)%。A、B两组患者均未出现骨水泥过敏、肺栓塞、椎管渗漏引起神经症状等严重并发症。无症状性骨水泥渗漏发生例数分别为7例和3例(P<0.05)。[结论]液压输送式椎体成形术与扩张球囊式椎体后凸成形术在改善单节段骨质疏松性脊柱骨折症状及功能方面疗效相当。二者骨水泥弥散情况和椎体高度恢复率的比较差异无统计意义,提示液压输送式椎体成形术在有着更简洁的手术过程、更简短的手术时间、更经济的手术花费的同时,在手术疗效以及结构恢复等方面都有着不差于扩张球囊式椎体后凸成形术的效果,而且对术后同椎、邻椎骨折的发生可能有着更好的预后。     

球囊扩张椎体后凸成形术治疗老年骨质疏松性椎体骨折

目的：探讨球囊扩张椎体后凸成形注入骨水泥治疗老年骨质疏松性椎体骨折的疗效。方法：对52例老年骨质疏松性单椎体骨折患者采用球囊扩张椎体后凸成形术治疗。在DSA透视引导下行单侧或双侧椎弓根穿刺,注入骨水泥。结果：发生骨水泥渗漏6例,术后1周腰背疼痛、后凸角度、伤椎高度、活动能力较术前明显改善（P〈0.05）,术后6个月、末次随访与术后1周,上述指标比较差异均无显著性（P〉0.05）。结论：球囊扩张椎体后凸成形注入骨水泥,不仅能够明显缓解骨质疏松性脊柱骨折导致的疼痛,而且可以部分恢复椎体高度和改善脊柱后凸畸形,有利于脊柱功能的恢复。     

经皮椎体后凸成形术骨水泥位置对术后疗效影响的对比分析

[目的]比较经皮椎体后凸成形术治疗骨质疏松压缩骨折术后骨水泥(poly methyl meth acrylate,PMMA)在椎体中的位置对疗效的影响.[方法]回顾性分析经皮椎体后凸成形术治疗骨质疏松椎体压缩骨折(单椎体)98例患者.根据术后骨水泥在椎体中的位置分为两组:侧方组(骨水泥偏于椎体一侧,未过中线)42例,中位组(骨水泥偏于椎体中央,越过中线)56例.测量并比较两组以下指标:手术前后VAS评分(10分制视觉模拟评分),ODI评分(Oswestry功能障碍指数,Oswestry disability index),SI(椎体矢状面指数,sagittal index,SI=椎体前缘高度/椎体后缘高度)及Cobb角.[结果]两组VAS、ODI评分、SI及Cobb角术前术后比较有统计学意义(P＜0.05);术前及术后两组间相比,VAS、ODI评分、SI及Cobb角均无统计学意义(P＞0.05);2组病例均未见患椎侧方再压缩.[结论]经皮椎体后凸成形术治疗骨质疏松椎体压缩骨折有较好的临床疗效,骨水泥在椎体中的分布位置对疗效没有显著影响,骨水泥偏一侧者不会增加椎体再次侧方压缩的风险.     

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.     

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.     

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.     

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.