胸椎椎弓根形态测量研究

目的:观察不同节段胸椎椎弓根形态特征,探讨其临床意义。方法:测量40具国人胸椎标本的椎弓根横径、矢状径、矢状面夹角、椎弓根间距、椎弓根后缘皮质到椎体前缘皮质距离及椎弓根-椎板夹角,观察椎弓根后缘中点与相应横突根部的关系。结果:（1）除T1外,各节段椎弓根矢状径均明显大于横径（P<0.01）;（2）椎弓根矢状面夹角从T1到T9逐渐减小,T10以下为负角;（3）椎弓根后缘皮质沿其轴线到椎体前缘的长度从T1到T7逐渐增加,T7到T12基本相同;（4）T1与T12椎弓根螺钉拟进钉点位于横突根部中点,T2及T11位于横突根部中上1/3点,其余各节段均位于横突根部上缘。结论:进行胸椎椎弓根螺钉固定时,应根据不同节段椎弓根形态特点,结合X线片或CT片,选择相应的螺钉直径、长度、进钉部位及方向。     

强直性脊柱炎患者中下胸椎椎弓根的影像学特征及临床意义

目的 :比较强直性脊柱炎(ankylosing spondylitis,AS)患者与非AS患者T5～T12椎弓根CT扫描的影像学参数,为AS患者椎弓根螺钉置钉提供参考依据。方法:选取2003年1月～2017年6月我科收治的具有完整临床资料及中下胸椎CT平扫和三维重建的AS男性患者40例(AS组),年龄34～53岁(40.5±4.2岁);选取同期我科收治的具有完整临床资料及中下胸椎CT平扫和三维重建的胸椎骨折男性患者40例(非AS组),年龄32～48岁(38.5±3.7岁)。分别测量T5～T12的椎弓根宽度(pedicle width,PW)、椎弓根高度(pedicle height,PH)、椎弓根与椎体正中矢状面夹角即内倾角(pedicle transverse angle,PTA)、椎弓根间距(pedicles distance,PD)和椎弓根钉道长度(pedicle screw path length,PL)。比较两组患者的测量结果。结果:AS组和非AS组PW从T5～T12逐渐增大,AS组PW均小于非AS组,两组比较有统计学差异(P0.05);两组T5～T12的PH无统计学差异(P0.05);两组PTA变化趋势一致,从T5～T12逐渐变为负数(T5～T10为正,T11～T12为负),AS患者在T5～T10较非AS组小,而在T11、T12较非AS组大,两组间比较均有统计学差异(P0.05);两组PD和PL从T5～T12逐渐增大,AS患者大于非AS组患者,两组间比较有统计学差异(P0.05)。结论:AS患者中下胸椎椎弓根较细长,行中下胸椎椎弓根螺钉内固定时可选用较长椎弓根螺钉以增加内固定强度,但不适宜增加椎弓根螺钉直径,置钉角度接近垂直,必要时可经椎弓根-肋骨途径置钉。     

胸椎椎弓根-肋骨复合体的解剖及影像学研究

目的 探讨胸椎椎弓根-肋骨复合体的解剖结构影像学特点及其临床意义.方法 取4具成人新鲜尸体胸椎脊柱标本.主要测量参数(数据)包括:椎弓根及椎弓根-肋骨复合体的横径、螺钉最长值、矢状角,以及椎弓根、椎弓根-肋骨复合体以及椎弓根-肋骨重叠的纵径.测量中将尸体标本与CT影像测量(含二维、三维重建)相结合.结果 椎弓根-肋骨复合体是一立体结构,椎弓根与肋骨不在同一平面,且两者位置关系随不同节段而发生变化.椎弓根-肋骨复合体纵径值T1最小,为(12.6±0.8)mm,T11最大,为(16.9±1.1)mm.椎弓根-肋骨重叠纵径值T1最小,为(7.2±0.3)mm,T10最大,为(11.8±1.0)mm.椎弓根纵径与椎弓根-肋骨复合体纵径间差异无统计学意义(P＞0.05),椎弓根纵径、椎弓根-肋骨复合体纵径均与椎弓根-肋骨重叠纵径间差异有统计学意义(P＜0.05).结论 椎弓根-肋骨复合体是一较复杂的立体结构,椎弓根-肋骨重叠纵径应被视为该复合体的真实或有效纵径.     

上胸椎前路逆向椎弓根螺钉内固定技术的可行性研究

【摘要】 目的：通过放射解剖学研究及标本上的模拟手术操作来验证上胸椎（T1~T4）前路逆向椎弓根螺钉内固定技术的可行性及安全性。方法：在放射科CT数据库中选取40例层厚为0.625mm的正常上胸椎薄层CT扫描数据（男20例,女20例,年龄18～68岁,平均39.7岁）,对数据进行MPR重建,在每侧椎弓根轴心上选取其横切面和矢状面进行观察和测量,测得每侧椎弓根的横径、高度、横切面进钉点距离、进钉角度、矢状面进钉点距离、进钉角度、钉道长度,对所得数据进行统计学处理。选取10具（男5例、女5例,年龄不详）完整的成人上胸椎防腐标本（包括C7～T6）,外观无畸形和破损,完整保留T1～T4两旁肋椎关节及椎旁软组织,于椎体前方逆向置入椎弓根螺钉,通过X线透视、CT扫描、剖面观察、测量,参照Rao等的椎弓根螺钉穿破分级标准对置钉优良率进行评测。结果：T1～T4椎弓根横径逐渐减小8.14～3.47mm;椎弓根高度逐渐增大6.89～10.29mm;横切面进钉角度逐渐减小32.96°～11.64°;横切面进钉点距离逐渐增大1.80～5.50mm;矢状面进钉角度逐渐增大104.95°～115.74°;矢状面进钉点距离逐渐增大5.95～8.76mm;钉道长度32.95～35.96mm。T3、T4椎弓根横径过于细小,不适合逆向椎弓根螺钉的置入,但在T3、T4逆向置入椎弓根-肋骨复合体螺钉是可行的。T1、T2前路逆向椎弓根螺钉的规格为：直径4.0mm、长度35mm左右,T3、T4前路逆向椎弓根-肋骨复合体螺钉的规格为：直径5.0mm、长度35mm左右。在10具上胸椎标本上共置钉80枚,根据Rao等的椎弓根螺钉穿破分级标准,总体优良率达90%,其中椎弓根侧壁穿破小于2mm未造成脊髓压迫的共7枚;椎弓根内侧壁穿破距离在2～4mm的共有5枚,分别为T1椎体1枚,T3椎体1枚,T4椎体3枚,有不同程度脊髓压迫;椎弓根内侧壁穿破距离大于4mm的2枚,其中T2椎体1枚,T4椎体1枚,脊髓受压严重;T2椎体有1枚椎弓根外侧壁穿破。结论：T1、T2椎体前路逆向椎弓根螺钉内固定技术和T3、T4椎体前路逆向椎弓根-肋骨复合体螺钉内固定技术可达到双皮质固定的目的,但其安全性及临床实用性尚需进一步探讨。     

胸椎骨折椎弓根螺钉内固定的临床研究

目的总结分析胸椎骨折椎弓根螺钉入点和角度。方法对16例胸椎骨折行椎弓根螺钉内固定,术后经CT或MRI复查,总结分析T1～T10共108枚椎弓根螺钉位置。结果34枚螺钉穿出椎弓根或椎体,穿出率31.48%。74枚螺钉未穿出椎弓根及椎体,其中71枚矢状夹角在10°～20°之间,入钉点均在关节突关节外缘。结论胸椎椎弓根狭窄,经椎弓根螺钉容易穿出,选择关节突关节的外缘与横突基底的上缘交点,10°～20°矢状夹角进钉,必要时可运用椎弓根外螺钉置钉是安全牢靠的方法。     

经胸椎椎弓根-肋骨途径置入螺钉安全角度的CT测量

目的：探讨胸椎T1～T10经椎弓根-肋骨途径置入螺钉的安全角度及变化规律。方法：选取156例正常成人的胸椎CT薄层扫描资料，其中男96例，女60例；年龄18～54岁，平均39岁。在胸椎CT片上测量T1～T10椎弓根-肋骨的横径、经椎弓根-肋骨途径置入的螺钉与矢状面的最小与最大安全成角及安全角度范围。结果：从T1～T4椎弓根-肋骨的横径逐渐减小．T5～T10逐渐增大：置钉安全角度范围T1与T2比较及T5～T10无显著性差异（P〉0．05），而T2与，T3及T4与T5比较均有显著性差异（P〈0．05），T1、T2置钉安全角度范围最大，T5～T10次之，T3、T4最小；男性与女性比较无显著性差异（P〉0．05）。结论：T1～T10胸椎的椎弓根-肋骨横径大小不同。经此途径置钉安全角度的大小亦不完全相同。     

椎弓根螺钉置入对幼犬胸椎形态发育的影响

目的:通过动物实验观察椎弓根螺钉置入对胸椎形态发育的影响。方法:将16只2月龄幼犬随机分为3组,A组(3只)为空白对照组,自T7～T13后路切开,显露椎板;B组(5只)为对照组,以螺钉穿过神经弓中心软骨联合对目标椎椎弓根仅做隧道破坏,螺钉不置留;C组(8只)为实验组,螺钉穿过神经弓中心软骨联合并留置于椎弓根内。实验的目标椎设计为T8、T10、T12,目标椎的上下两个脊椎的各相应测量指标取平均值做为其自身对照。应用CT测量并观察脊椎的形态学指标变化。结果:术后3个月,C组目标椎椎管面积、椎管横径、椎管纵径、椎弓根长度与相邻脊椎平均值比较显著减少(P<0.05),而A组、B组间未发现明显差异;各组椎体横径、椎体纵径、椎体高度测量结果显示目标椎与相邻脊椎平均值无显著性差异(P>0.05)。结论:椎弓根螺钉内固定术对于幼犬胸椎椎管、椎弓的发育有显著影响,有可能导致医源性椎管狭窄;对于椎体发育无明确影响。     

T4椎弓根-肋骨复合体横纵径的相关测量

目的:测量T4椎弓根-肋骨复合体的横纵径相关数据并探讨其意义。方法:12例随机成人胸椎,男7例,女5例;平均年龄23岁(19～28岁)。采用病例自身对照分组,即同一病例、同侧T4椎弓根与椎弓根-肋骨复合体对照。所用设备为GE公司Lightspeed16排螺旋CT,自T3至T5行CT扫描及三维重建。测量参数:椎弓根横径、椎弓根-肋骨复合体横径、椎弓根纵径、椎弓根-肋骨复合体纵径、椎弓根-肋骨复合体重叠纵径。结果:T4椎弓根-肋骨复合体中的椎弓根与肋骨部分重叠,椎弓根横径与椎弓根-肋骨复合体的横径比较差异有统计学意义(P<0.05);椎弓根纵径与椎弓根-肋骨复合体纵径间比较差异无统计学意义(P>0.05),椎弓根-肋骨复合体重叠纵径与椎弓根纵径或复合体纵径间差异均有统计学意义(P<0.05)。结论:T4椎弓根-肋骨复合体中椎弓根与肋骨是部分而非完全重叠,且椎弓根或复合体的纵径均不能等同于重叠纵径。     

青少年胸椎椎弓根影像学特征及其临床意义

目的 :探讨青少年胸椎椎弓根影像学特征及其临床意义。方法 :随机选择正常青少年 42人 ,平均年龄12 .4岁 ,摄胸椎X线片 ,对 2 7人行全胸椎椎弓根CT扫描 ,分别测量各节段椎弓根横径、螺钉进钉点和深度 ,以及椎弓根轴线与矢状面夹角等 ,并根据X线测量方法 ,对 10 3例脊柱侧凸患者进行节段椎弓根螺钉器械矫正。结果 :正常C4椎弓根横径最小 (3 .9± 0 .66)mm ,胸椎椎弓根钉进钉点均位于横突根部上缘与中点之间 ,T11、12 椎弓根矢状角为负角 ,其余为正角。 10 3例患者共置入 10 82枚胸椎椎弓根螺钉 ,穿透椎弓根内外侧及椎前皮质的螺钉分别占 18.6%、 14 .5 %和 2 .1% ,仅 1例患者出现了与椎弓根穿透内侧皮质有关的神经系统症状 ,无其他相关并发症。结论 :认真阅读X线片 ,了解与掌握不同节段椎弓根形态特征及周围解剖关系 ,有助于进行正确的胸椎椎弓根螺钉置入。     

胸椎椎弓根螺钉治疗上胸椎严重骨折

目的：探讨胸椎椎弓根螺钉治疗上胸椎严重骨折的方法及疗效。方法：自2000年3月至2008年6月回顾性分析18例上胸椎严重骨折患者的临床资料,男10例,女8例;年龄20～76岁,平均34.3岁。按Denis分型：爆裂骨折15例,骨折伴脱位3例。损伤节段：T1-T22例,T32例,T3-T42例,T4-T58例,T5-T62例。Wolter外伤性椎管狭窄分型：Ⅰ型9例,Ⅱ型7例,Ⅲ型2例。Frankel分级：A级5例,B级4例,C级2例,D级4例,E级3例。均采用后路胸椎椎弓根螺钉固定治疗,手术前后通过影像观察Cobb角及椎管狭窄度,通过Frankel分级的变化评估神经症状,通过CT复查术后椎弓根螺钉与椎弓根的位置。结果：18例患者均获随访,时间1～6年,平均2.3年。Cobb角由术前的（26.50±5.62）°改善为术后的（21.20±3.54）°（P〈0.05）;椎管内占位改善率61%。术后Frankel分级：A级4例,B级2例,C级3例,D级3例,E级6例,手术前后Frankel分级有明显改善（P〈0.05）。CT复查示椎弓根螺钉88.5%（69/78）位于椎弓根内。结论：后路椎弓根螺钉固定方法是坚强、安全、有效的胸椎严重骨折的治疗方法。     

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.     

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.     

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.