腹腔镜下肝切除术的临床疗效及对细胞免疫功能的影响

目的:分析腹腔镜下肝切除术的临床疗效及对细胞免疫功能的影响。方法:回顾分析97例行肝切除术肝癌患者的临床资料,分为观察组(n=48,行腹腔镜下肝切除术)与对照组(n=49,行开腹肝切除术)。对比两组术中指标、术后近期疗效、远期疗效、并发症发生情况及手术前后不同时间点的外周血淋巴细胞亚群、血清白介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)表达水平。结果:两组转移率、复发率、死亡率、并发症发生率差异均无统计学意义(P0.05);术后72 h,观察组CD3、CD4、CD8、IL-6、TNF-α表达水平基本恢复至术前水平,对照组CD3、CD4、CD8仍低于术前水平,IL-6、TNF-α仍高于术前水平,差异有统计学意义(P0.05)。结论:腹腔镜下肝切除术治疗肝癌的临床疗效确切,创伤小,安全性较高,近期疗效优于开腹肝切除术,且对患者的细胞免疫功能影响小,术后康复快。     

腹腔镜与开腹结直肠癌根治术对机体免疫系统影响的比较研究

目的:比较腹腔镜手术与传统开腹手术对患者免疫机能的影响。方法:2006年12月至2007年7月收治结直肠癌患者60例,分别行腹腔镜手术和开腹手术各30例,于术前1d和术后第3天、第7天抽取外周静脉血,比较两组患者的C反应蛋白,IgA,IgM,IgG,IL-6,CD3+,CD4+,CD8+细胞和NK细胞,比较术前1d和术后第1天、第3天TNF-α细胞活性。结果:术后第3天患者CD3+,CD4+,CD8+细胞活性及CD4+/CD8+差异无显著性,但术后第7天腹腔镜较开腹组明显低。术后第3天IL-6开腹组明显高于腹腔镜组。C反应蛋白于术后第3天开腹组高于腹腔镜组。IgM于术后第3天开腹组高于腹腔镜组,IgA、IgG无显著统计学意义。TNF-α于术后第3天开腹组高于腹腔镜组。结论:腹腔镜结直肠癌根治术较传统开腹手术对机体免疫机能影响较小。     

三孔法腹腔镜与开腹直肠癌根治术后应激及免疫功能的对比研究

目的:比较三孔法腹腔镜与开腹直肠癌根治术对应激及免疫功能的影响。方法:选取2013年6月至2014年4月收治的直肠癌患者,其中26例行改良三孔法腹腔镜直肠癌根治术(三孔组),47例行开腹直肠癌根治术(开腹组)。两组患者分别于术前1 d及术后第1天、第3天、第7天清晨抽取外周静脉血,测定白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor,TNF-α)、C反应蛋白(C-reactive protein,CRP)、免疫球蛋白A(immunoglobulin A,Ig A)、免疫球蛋白G(immunoglobulin G,Ig G)、免疫球蛋白M(immunoglobulin M,Ig M)及CD4+、CD8+水平的变化。结果:术前两组患者血清学检测指标差异均无统计学意义(P0.05)。术后第1天、第3天,IL-6、TNF-α逐渐升高,此后下降,三孔组术后第3天IL-6、TNF-α水平明显低于同期开腹组(P0.05)。术后CRP水平均升高,且术后第3天达到峰值;术后第7天,三孔组明显低于同期开腹组,差异有统计学意义(P0.05)。两组患者术后Ig A、Ig G、Ig M及CD4+、CD8+含量较术前降低;术后第3天,三孔组Ig M含量明显高于同期开腹组,差异有统计学意义(P0.05);术后第7天,CD4+、CD8+水平明显高于同期开腹组,差异有统计学意义(P0.05)。结论:与开腹手术相比,三孔法腹腔镜直肠癌根治术患者的应激反应轻,免疫抑制程度低,进一步体现了腹腔镜手术的优越性。     

腹腔镜辅助与开腹进展期胃癌根治术对机体免疫功能影响的比较

目的:腹腔镜辅助下与开腹行进展期胃癌根治术对机体免疫功能的影响.方法:将94例进展期胃癌患者按意愿分为腹腔镜组(n=47)与开腹组(n=47),测定2组术前及术后第3、7、14天患者血清IL-6、CRP、IgG、IgM、IgA、CD3+、CD4+,CD8+,CD4+/CD8+、人类白细胞抗原Ⅱ型(HLA-DR)、中性粒细胞(PMN)的数量.结果:2组术后第3天免疫球蛋白较术前均降低(P<0.05),开腹组术后第7天免疫球蛋白较术前低(P<0.05),腹腔镜组术后第7天免疫球蛋白较术前比较差异无统计学意义(P>0.05),除术后第3、7天IgM腹腔镜组高于开腹组(P<0.05),2组间IgA、IgG术后差异无统计学意义(P>0.05);2组术后第3、7天2组IL-6、CRP较术前明显升高(P<0.01),开腹组升高较腹腔镜组更明显(P<0.01);术后第3、7、14天腹腔镜组HLA-DR较术前明显升高(P<0.01),2组间差异有统计学意义(P<0.01,表5);2组术后第3天PMN较术前明显升高(P<0.01);2组外周血CD3+、CD4+,CD4+/CD8+术后第7、14天较术前均明显下降(P<0.01),术后腹腔镜组明显高于开腹组(P<0.01),且腹腔镜组较早恢复正常.结论:与开腹手术相比,腹腔镜手术对机体术后的免疫功能影响小,术后恢复快.     

腹腔镜直肠前切除术对机体和局部免疫应激反应的影响

目的:比较腹腔镜和开腹直肠前切除术对患者机体和局部免疫应激反应的影响.方法:选择同期腹腔镜和开腹直肠前切除术患者各25例,于术前1 d和术后第1、3、5 d测定血清IL-6、IL-8、C反应蛋白、TNF-α.术后第1、2、3 d测定腹腔引流液中IL-6、IL-8、TNF-α.结果:腹腔镜组术后血清IL-6、C反应蛋白水平明显低于开腹组(P<0.05),但腹腔引流液中IL-6、IL-8水平未见明显差别(P>0.05).结论:腹腔镜直肠前切除术相对开腹手术对机体全身的免疫功能影响小,但对患者局部免疫应激反应的影响差异无显著性意义.     

腹腔镜与开腹肝癌左外叶切除术对患者围术期指标、免疫功能及术后康复的影响

目的观察腹腔镜与开腹肝癌左外叶切除术对患者围术期指标、免疫功能及术后康复的影响。方法回顾性分析2014年1月～2019年3月于本院行左外叶肝癌切除术患者临床资料,经倾向性匹配后得到腔镜组(行腹腔镜肝左外叶切除术)与开腹组(行开腹肝左外叶切除术)各46例,比较两组围术期指标,分析两组术前1d、术后第1天、术后第3天细胞免疫淋巴细胞亚群(CD3、CD19、NK、CD4/CD8)及体液免疫免疫球蛋白(IgG、IgA、IgM)变化,同时对比两组术后康复情况及并发症发生情况。结果腔镜组手术切口长度、术中失血量及术后镇痛药使用时间均显著低于开腹组(P0.05);两组术后第1天细胞免疫指标(CD3、CD19、NK、CD4/CD8)、体液免疫指标(IgA、IgM、IgG)均显著低于术前1d(P0.05),术后第3天,两组上述指标均有回升趋势,但腔镜组CD3、CD19、NK、CD4/CD8及血清IgA、IgM、IgG水平均显著高于开腹组(P0.05);腔镜组术后疼痛评分、术后首次排气时间、首次下床活动时间、首次进食流食时间、腹腔引流管拔除时间及术后住院时间均显著低于开腹组(P0.05);腔镜组术后并发症总发生率10.87%,显著低于开腹组的30.43%(P0.05)。结论腹腔镜肝癌左外叶切除术相较传统开腹手术而言,能减轻患者创伤,降低手术对患者免疫功能的影响,利于术后恢复,同时减少并发症发生几率。     

腹腔镜和开腹直肠癌全直肠系膜切除对机体免疫功能的影响

目的比较经腹腔镜和开腹行直肠癌全直肠系膜切除保留肛门手术对患者免疫功能的影响。方法将 37例行直肠癌全直肠系膜切除保肛术患者分为开腹组 (n =2 1)和腹腔镜组 (n =16 ) ,于术前 1天、术后第 1天、术后第 5天检测血清IL 2、IL 6、TNFα值。术前 1天和术后第 5天检测全血CD3 CD5 6 T细胞和CD3-CD5 6 NK细胞的百分比 ,血清免疫球蛋白IgG、IgM、IgA值。IL 2、IL 6、TNFα值的检测用酶联免疫吸附法 (ELISA) ,Ig的测定用免疫散射比浊法 ,CD3 CD5 6 T细胞和CD3-CD5 6 NK细胞用流式细胞仪进行检测。结果两组手术对CD3 CD5 6 T细胞、CD3-CD5 6 NK细胞、IL 2、IL 6、TNFα和免疫球蛋白的影响差异无显著性意义 (P >0 0 5 )。结论腹腔镜和开腹直肠癌全直肠系膜切除术对患者免疫功能的影响差异无显著性意义。     

腹腔镜与开腹结直肠癌手术对机体应激反应及细胞免疫功能影响的比较

比较腹腔镜与开腹结直肠癌根治术对机体应激反应及细胞免疫功能的影响,为腹腔镜手术在结直肠肿瘤中的优势提供依据。选择同一手术组的结直肠癌患者45例,随机分为腹腔镜手术组21例(LCR组)和开腹手术组24例(OCR组),分别在术前1 d和术后第1、6天取外周静脉血,测定CRP、血清淀粉样蛋白A(SAA)、IL-6水平和CD3+、CD4+、CD8+细胞并进行比较。术后第1、6天LCR组的CRP、SAA、IL-6均明显低于OCR组,2组比较差异均有统计学意义(P0.01);术后第6天OCR组的CD3+、CD4+、CD4+/CD8+明显低于LCR组,2组比较差异有统计学意义(P0.01);2组患者手术前后不同时相点的CRP、SAA、CD3+、CD4+、CD4+/CD8+组内比较,差异均有统计学意义(P0.01),LCR组IL-6在术后第1天明显高于术前(P0.01),第6天接近术前水平(P0.05)。腹腔镜结直肠癌根治术对机体细胞免疫功能和应激反应的影响明显小于开腹手术。     

腹腔镜肝癌切除术对患者术后临床康复和体液免疫影响的临床对照研究

目的探讨腹腔镜与开腹肝癌切除术对患者临床康复和体液免疫功能的影响。方法选取2010年1月至2012年6月期间徐州医学院附属医院、江苏省肿瘤医院及南京中医药大学第二附属医院行腹腔镜及开腹肝癌左外叶切除术患者44例,其中腹腔镜组22例,常规开腹组22例。采用ELISA法测定患者术前1 d以及术后第l天和第5天外周血中IgG、IgA、IgM、C3、C4、C反应蛋白（CRP）、IL-2、IL-6及TNF-α水平的变化,同时比较2组患者的手术时间、术中出血量、住院时间及并发症发生情况。结果腹腔镜组患者术后镇痛剂使用时间为（1.9±0.8）d,首次进食时间为（2.2±0.5）d,住院时间为（6.3±1.3）d,均短于开腹组（P〈0.05）,但2组间的手术时间、术中失血量、并发症发生率及死亡率差异均无统计学意义（P〉0.05）。与术前相比,术后第1天2组患者的C3、C4、lgA、IgG、lgM和IL-2均明显降低（P〈0.05）,CRP、IL-6及TNF-α均明显升高（P〈0.05）;开腹组患者术后第l天的C3、C4、lgA、IgG、lgM和IL-2的下降幅度较腹腔镜组更明显（P〈0.05）。术后第5天,腹腔镜组患者的C3、C4、lgA、IgG、lgM及IL-2水平上升和CRP、IL-6及TNF-α水平下降并均接近术前水平;而开腹组患者的C3、C4、lgA、IgG、lgM及IL-2仍低于术前水平（P〈0.05）,CRP、IL-6及TNF-α仍仍高于术前水平（P〈0.05）。结论腹腔镜肝癌切除术后患者的恢复较快,且对患者机体体液免疫功能的影响小于开腹肝癌切除术。     

腹腔镜巨脾切除术对患者术后免疫功能的影响

目的 观察腹腔镜巨脾切除术对患者免疫功能的影响.方法 将26例巨脾、脾功能亢进患者随机分为腹腔镜巨脾切除组(LS)12例和开腹脾切除组(OS)14例,比较两组病例术前、术后1、7 d外周血淋巴细胞亚群及免疫球蛋白变化.结果 腹腔镜组术后1、7 d的成熟T淋巴细胞(CD3)、辅助T淋巴细胞(CD4)、CD4与抑制淋巴细胞(CD8)的比值及免疫球蛋白IgG、IgA、IgM与术前比较差异无统计学意义(P>0.05).开腹组术后1、7 d的CD3、CD4、CD4/CD8及IgG与术前比较明显下降(P<0.05).结论 腹腔镜巨脾切除术较开放脾切除术对患者免疫抑制程度轻.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

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.     

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.