胸椎椎弓根-肋骨单元与椎弓根的CT测量

目的:比较经胸椎椎弓根-肋骨单元(pedicle rib unit;PRU)置钉与传统经椎弓根置钉技术的相关径线;为临床应用提供依据.方法:对30例患者脊柱T1～T10节段进行薄层CT扫描;层厚为1mm;选择有完整PRU结构的CT横断面图像进行以下指标测量:(1)PRU宽度(PRU-W);椎弓根宽度(PW);(2)PRU钉道长度(PRU-L);椎弓根钉道长度(PL);(3)PRU中轴与矢状面夹角(PRU-A);椎弓根中轴与矢状面夹角(PA);(4)经PRU置钉的安全角度范围(△A).结果:PRU-W和PW均以T5最小;以T1为最大;由T1至T5逐渐减小;由T5至T10逐渐增大.PRU-L和PL以T1为最小;以T10为最大;由T1至T10逐渐增大.PRU-A和PA以T1为最大;以T10最小;由T1至T10逐渐缩小.PRU-L与PL、PRU-W与PW间均有显著性差异(P＜0.01).PRU-W、PRU-L在男女之间差异亦有统计学意义(P＜0.01).PRU置钉的安全角度范围△A为20°～30°.结论:胸椎PRU的横径、钉道长度均较同节段的椎弓根大;经PRU可置入更粗更长的螺钉;有更大的内倾角;安全置钉角度范围也较大.     

强直性脊柱炎伴胸腰椎后凸畸形腰椎及S1椎弓根的解剖特征及临床意义

目的:通过对强直性脊柱炎(ankylosing spondylitis,AS)伴胸腰椎后凸畸形和椎间盘退变性疾病(disc degenerative disease,DDD)患者L1-S1椎弓根CT扫描相关参数的测量,研究两者椎弓根解剖参数差异,为临床手术中置钉提供参考依据。方法:选取2012年3月至2014年11月行截骨矫形手术治疗并有完整术前临床及影像学资料的男性AS伴后凸畸形患者30例(AS组),年龄23~51岁,平均(35.7±9.5)岁,同时选取行手术治疗具有完整术前全腰椎及骶椎CT扫描全部附件结构影像清晰易辨的男性DDD患者30例(DDD组),年龄39~64岁,平均(52.4±8.9)岁。分别测量L1-S1节段椎弓根内聚角(pedicle transverse angle,EA),椎弓根矢状角(pedicle inclined angle,FA),椎弓根宽度(pedicle width,PW),椎弓根钉道长度(pedicle screw path length,PL),椎弓根高度(pedicle height,PH),统计比较是否存在差异。结果:AS组和DDD组椎弓根宽度(PW)自L1-S1均是逐渐增大的,AS组PW在L5、S1均显著大于DDD组,分别为(16.47±2.66)mm vs.(14.51±2.11)mm和(21.76±2.97)mm vs.(18.87±2.14)mm(P0.05);椎弓根钉道长度(PL)自L1-S1在AS组均大于DDD组(P0.05);PL两组最大值均在L3节段;AS组椎弓根内聚角(EA)在L1-S1均较DDD组小;AS矢状角(FA)在L3-S1显著小于DDD组(P0.05),分别为(-2.88±10.24)°,(-7.88±10.22)°,(-7.70±10.40)°,(-5.15±10.25)°vs.(4.05±2.21)°,(7.79±4.38)°,(7.07±3.21)°,(12.62±3.21)°。结论:在AS伴后凸畸形患者腰椎及S1椎弓根置钉时可选用更粗更长螺钉来增加内固定强度,需注意适当减小内聚角,并根据矢状面形态调整头尾向。     

超声骨动力椎弓根寻路器的研制及其引导置钉的可行性研究

目的 :探讨自行研制的超声骨动力椎弓根寻路器辅助椎弓根螺钉置入的准确度及安全性。方法 :自行研制一种超声骨动力椎弓根寻路器,选择2具成年人脊柱标本(T1～L5节段),男性1具,年龄62岁,女性1具,年龄57岁,排除畸形、外伤及骨质疏松症等骨科疾病,将标本左侧椎弓根设置为实验组,通过超声骨动力椎弓根寻路器引导下置钉;右侧椎弓根设置为对照组,直视下徒手置钉。术中及术后即刻分别对两组标本行CT扫描,通过术中CT测量定位针长轴中线距椎弓根内外侧皮质距离;通过术后CT测量椎弓根螺钉穿出椎弓根皮质的距离并依据Neo法对置钉进行分级,统计两组精确置钉(0级置钉)、可接受置钉(Neo分级0级或1级)和不良置钉(Neo分级2级或3级)的情况。通过比较两组精确置钉率与不良置钉率上的整体差异,以及分别在上、中、下胸椎及腰椎的穿破皮质螺钉(Neo分级1、2、3级螺钉)的差异,评估两组间置钉精确性与安全性的差异。结果:两组各置入34枚定位针。实验组与对照组的定位针在上胸椎距皮质骨最小距离分别为2.77mm±1.05mm和0.59±2.31mm,中胸椎为1.97±1.01mm和0.98±1.70mm,下胸椎为3.02±0.93mm和2.53±0.83mm,腰椎为4.14±1.04mm和3.80±0.59mm。实验组有6枚定位针存在穿出的风险,对照组有14枚存在穿出的风险。在置钉方面,实验组与对照组的精确置钉率分别为82.36%和58.82%,可接受置钉率分别为97.06%和82.36%,不良置钉率分别为2.94%和17.64%。在所有穿破皮质螺钉中,实验组有1枚位于上胸椎(1级),2枚位于中胸椎(1级、2级各1枚),2枚位于下胸椎(1级2枚),1枚位于腰椎(1级);而对照组有6枚位于上胸椎(1级2枚、2级2枚、3级2枚),5枚位于中胸椎(1级3枚、2级1枚、3级1枚),3枚位于下胸椎(1级)。实验组在胸腰椎精确置钉率、可接受置钉率上明显高于对照组,而在不良置钉率上明显低于对照组,且差异均具有统计学意义(P0.05)。实验组与对照组在上胸椎节段(T1～T4)穿破皮质螺钉比率存在统计学差异(P0.05),而在中下胸椎及腰椎无统计学差异(P0.05)。结论:与徒手置钉相比,超声骨动力椎弓根寻路器引导下置钉在胸腰椎节段具有较高的准确性与安全性。     

术中CT导航在脊柱侧凸后路胸椎椎弓根螺钉植入术中的应用

目的探讨术中CT导航在脊柱侧凸后路胸椎椎弓根螺钉植入术中的应用价值。方法回顾分析2009年10月-2011年12月行脊柱后路矫形融合术的46例胸弯脊柱侧凸患者临床资料,比较术中CT导航下(A组,21例)和传统C臂X线机下徒手(B组,25例)植入胸椎椎弓根螺钉的准确性和安全性。两组患者性别、年龄、脊柱侧凸类型、累及节段、主胸弯Cobb角等一般资料比较,差异均无统计学意义(P>0.05),具有可比性。A、B组各植入胸椎椎弓根螺钉273枚及308枚。采用Modi等方法,通过术中CT扫描对椎弓根螺钉位置分级,计算两组在上胸椎(T1～4)、中胸椎(T5～8)、下胸椎(T9～12)和整个胸椎(T1～12)的准确植钉率、安全植钉率和潜在危险植钉率。结果 A组整个胸椎的准确植钉率(93.4%)、安全植钉率(98.9%)均显著高于B组(83.8%、92.5%),潜在危险植钉率(1.1%)显著低于B组(7.5%),比较差异均有统计学意义(P<0.05)。两组上、中、下胸椎的准确植钉率、安全植钉率和潜在危险植钉率比较,差异均无统计学意义(P>0.05)。根据CT评估结果将潜在危险植钉重新植钉或去除。术后3 d根据神经系统体检评定两组均无神经功能缺失发生。结论与传统C臂X线机下徒手植钉技术相比,术中CT导航可提高胸椎椎弓根螺钉植入的准确性和安全性,可在术中发现危险螺钉并及时去除或修正,保障手术安全。     

图像处理系统在强直性脊柱炎胸椎椎弓根螺钉植入患者中的临床应用

目的:通过在图像处理系统引导下进行强直性脊柱炎胸椎椎弓根螺钉植入的研究,探讨图像处理系统在胸椎椎弓根螺钉植入的临床应用效果。方法:选取手术治疗的强直性脊柱炎合并胸椎管狭窄症患者5例,在图像处理系统引导下植入椎弓根螺钉。术后进行CT扫描判断置钉的效果。结果:5例患者共植入46枚椎弓根螺钉,术后判断置钉优良率为98%,与徒手置钉比较,差异有统计学意义(P0.05)。结论:应用图像处理系统在强直性脊柱炎胸椎椎弓根螺钉的植入能显著提高安全性,具有临床应用价值。     

脊柱手术机器人在胸腰段窄小椎弓根后路螺钉置入中的应用

目的 探讨Renaissance脊柱手术机器人在胸腰段窄小椎弓根后路螺钉置入中的应用。方法 对156例胸腰段窄小椎弓根的脊柱疾病患者行后路螺钉置入,窄小椎弓根双侧中一侧采用脊柱手术机器人辅助置入椎弓根螺钉,另一侧采用传统方法置入椎弓根螺钉。术后采用Abul-Kasimhierarchy分级系统评价椎弓根螺钉置入的优良性。结果 在T10～L3窄小椎弓根共置入椎弓根螺钉456枚,其中胸椎置钉60枚,置钉优良率机器人辅助侧为93. 3%(28/30),传统手术侧为80. 0%(24/30),两侧比较差异有统计学意义(P 0. 05);腰椎置钉396枚,置钉优良率机器人辅助侧为96. 0%(190/198),传统手术侧为81. 8%(162/198),两侧比较差异有统计学意义(P 0. 05)。结论 Renaissance脊柱手术机器人辅助胸腰段窄小椎弓根螺钉置入能提高置钉优良率。     

引导通道辅助下经皮椎弓根置钉与传统经皮椎弓根置钉的比较

目的 :比较引导通道辅助下经皮椎弓根置钉与传统透视下经皮椎弓根置钉的手术时间、射线暴露时间和置钉准确性。方法:70例无神经症状的胸腰椎骨折患者,随机分为A、B两组,A组35患者采用传统透视下经皮置入椎弓根螺钉,共置入180枚椎弓根螺钉;B组35例患者采用引导通道辅助下经皮置入椎弓根螺钉,共置入178枚椎弓根螺钉,均由同一术者完成置钉。记录两组椎弓根置钉时间、射线暴露时间,术后连续2次复查手术节段CT对两组病例置钉准确性进行评估并分级。比较两组患者单枚椎弓根螺钉置钉时间、射线暴露时间和置钉准确性。结果:两组患者年龄、体重指数、合并疾病、骨折类型、性别比例均无统计学差异(P0.05)。A组单枚椎弓根螺钉平均置钉时间为14.11±3.32min,B组为11.35±2.82min,两组比较差异有统计学意义(P=0.0042)。A组平均射线暴露时间为12.07±3.06s,B组为8.06±2.15s,两组比较差异有统计学意义(P=0.0031)。A组155枚(86.11%)螺钉为A级置钉,23枚螺钉(12.78%)为B级置钉,1枚螺钉(0.56%)为C级置钉,1枚螺钉(0.56%)为D级置钉;B组156枚螺钉(87.64%)为A级置钉,20枚螺钉(11.24%)为B级置钉,1枚螺钉(0.56%)为C级置钉,1枚螺钉(0.56%)为D级置钉,两组比较差异无统计学意义(P0.05)。结论 :引导通道辅助下经皮椎弓根置钉与传统经皮椎弓根置钉具有相同的准确性,但能明显减少置钉时间及辐射暴露时间。     

数字化导航模板辅助胸椎椎弓根螺钉置钉实验研究

目的探讨数字化导航模板辅助胸椎椎弓根螺钉置入的准确性和可行性。方法将20具尸体胸椎标本随机分为两组,每组10具标本,由同一位具有一定腰椎椎弓根螺钉置钉经验但无胸椎椎弓根螺钉置钉经验的骨外科医师分别采用导航模板法和徒手法进行胸椎椎弓根螺钉的置入手术。术后CT扫描比较两种方法的置钉准确性。结果导航模板法和徒手法各置入240枚螺钉。对两种方法的置钉准确率及风险螺钉发生率进行比较,导航模板法的置钉准确率高于徒手法,风险螺钉发生率低于徒手法,差异有统计学意义（P〈0.05）。徒手法学习曲线明显,导航模板法学习曲线不明显。结论数字化导航模板辅助胸椎椎弓根螺钉置入安全可行,手术操作简单,置钉准确率高,为胸椎椎弓根螺钉置入提供了一种新的方法。     

青少年特发性胸椎侧凸患者胸椎椎弓根横径的分型及其临床意义

目的 探讨胸椎椎弓根横径的测量及分型在青少年特发性胸椎侧凸患者治疗中的临床意义.方法 对2008年10月至2009年7月收治的30例青少年特发性胸椎侧凸患者(侧凸组)和2008年8月至2009年7月于本院就诊的20例年龄匹配的非侧凸青少年患者(对照组)采用螺旋CT行胸椎连续扫描,在图像编档和通信系统(PACS)上逐层阅片,选择胸椎椎弓根显示最清楚的层面对椎弓根横径进行测量,并根据测量结果将其分为4型.分别对侧凸组凹凸侧和对照组左右侧椎弓根横径进行对比,并对侧凸组与对照组椎弓根分型的构成比进行分析.结果 两组患者胸椎椎弓根横径T1～4逐渐减少,T5～12逐渐增加.对照组同节段双侧胸椎椎弓根横径差异无统计学意义(P>0.05).侧凸组顶椎区凹侧的椎弓根横径明显小于凸侧,差异有统计学意义(P<0.05).侧凸组中4型椎弓根的比例明显高于对照组,1型椎弓根的比例低于对照组,差异均有统计学意义(P<0.05).结论 青少年特发性胸椎侧凸患者胸椎椎弓根横径常较小,术前应根据CT胸椎椎弓根形态制定置钉策略,以减少经胸椎椎弓根置入螺钉的并发症的发生.     

颈胸段脊柱侧块螺钉和椎弓根螺钉的抗拔强度的研究

目的　分析颈胸段脊柱后路不同置钉方法的拔出强度。方法　 5例新鲜尸体脊柱C6～T4椎骨 ,分解为单个椎体 30个 ,共 6 0个椎弓根。对其中的颈椎分为两组 ,分别为侧块螺钉固定组 (Roy -Camille法 ,Magerl法 ,Anderson法 ,自行设计侧块螺钉植入法 )和椎弓根螺钉固定组。将 6 0个椎弓根分组进行拔出测试 (5mm/min的速度垂直方向拔出 )。胸椎全部用椎弓根螺钉固定。结果　Roy-Camille法和Magerl法最大的拔出力接近 ,自行设计侧块螺钉植入法较Magerl法明显增加 ,而椎弓根螺钉抗拔出力最大。结论　选用侧块后正中线中下 1 / 3作为进针点 ,其抗拔出强度明显增加 ,钉道增加 ,操作简便 ;而颈胸椎椎弓根螺钉的拔出强度均大于侧块螺钉     

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.     

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.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.