地佐辛复合罗哌卡因在腹腔镜胆囊切除术后的作用

目的:观察地佐辛复合腹腔内喷洒罗哌卡因用于腹腔镜胆囊切除术(LC)后的镇痛效果.方法:选择60例择期行LC的患者,随机分为地佐辛复合罗哌卡因组(观察组)和单纯地佐辛组(对照组),每组30例.两组均于缝合戳口前静脉注射地佐辛5 mg,观察组于气腹建立后向胆囊表面、胆囊床、肝膈间隙喷洒0.5%罗哌卡因14 mL,在缝合腹壁戳口前向每个戳口局部注射相同药液2 mL.结果:观察组术后2 h、6 h、12 h、24 h的VAS评分显著小于对照组(P＜ 0.01),术后2 h和次日晨8时Cor、ACTH、CRP低于对照组(P＜ 0.05);术后镇痛药的使用例数小于对照组(P＜ 0.05);对照组术后镇痛药首次应用时间早于观察组(P＜ 0.05).结论:LC中腹腔内喷洒罗哌卡因复合地佐辛术后镇痛,减少了术后镇痛药的使用量,且能有效地抑制围术期应激反应.     

腹壁局麻复合胆囊床浸润麻醉对术后疼痛的影响

目的 探讨气腹前腹壁用罗哌卡因局麻和胆囊床放置含罗哌卡因、芬太尼混合液的明胶海绵对腹腔镜胆囊切除术后疼痛的影响.方法 腹腔镜胆囊切除术的患者50例,随机均分为研究组和对照组.研究组采用0.45罗哌卡因20 ml在腹壁三个打孔处局部麻醉,并于胆囊切除止血后,胆囊床处放置明胶海绵两片(含0.9%的罗哌卡因和0.05 mg芬太尼的混合液5 ml).对照组除腹壁浸润注射生理盐水外,并在胆囊切除后,静脉给予芬太尼0.05 mg.记录术后1、2、3、6、9和24 h的VAS评分.结果 研究组术后各时点静息、运动VAS评分小于对照组(P<0.05).术后研究组右肩痛发生率、镇痛药使用率明显低于对照组(P<0.05).结论 腹壁局部麻醉和胆囊床放置含罗哌卡因和芬太尼的明胶海绵,对腹腔镜胆囊切除术后的疼痛有减轻作用.     

罗哌卡因对腹腔镜胆囊切除术患者的镇痛效果

目的探讨切口内浸润及胆囊床喷洒盐酸罗哌卡因对腹腔镜胆囊切除术患者术后镇痛效果和安全性。方法选择在全麻下行腹腔镜胆囊切除术患者160例,随机分为4组。A组:在作腹壁切口前切口预定点注入0.75%盐酸罗哌卡因2 mL;B组:手术结束前向胆囊床喷洒盐酸罗哌卡因10 mL;C组:联合应用A/B组的处理;D组:不做任何以上处理。各组在术后均持续监测患者血氧饱和度、呼吸、血压、心电图,记录术后2、6、12、24 h的VAS评分、Ramsay评分和术后额外镇痛药使用情况及副作用发生情况。观察术前30 min、术后180min静脉血皮质醇含量。结果A、B、C三组术后12 h的VAS评分低于D组(P0.05);4组患者各时间点Ramsay评分差异无统计学意义(P0.05);A、B、C三组额外镇痛药使用次数少于D组(P0.05);4组患者副作用发生情况差异无统计学意义(P0.05);A、B、C三组在术后180 min血液中皮质醇含量少于D组(P0.05)。结论罗哌卡因对腹腔镜胆囊切除术患者具有很好的镇痛效果,联合切口处浸润和胆囊床表面喷洒罗哌卡因的效果更佳,具有较好的安全性。     

经腹膜腔给局麻药对腹腔镜胆囊切除术后镇痛效果的影响

目的探讨腹腔镜胆囊切除（laparoscopic cholecystectomy,LC）术中腹腔内应用局麻药的镇痛效果及其对LC不良反应的影响。方法36例ASAⅠ～Ⅱ级行择期LC患者据随机数字表分为3组,Ⅰ组LC术前腹膜腔喷洒0.5%罗哌卡因30 ml;Ⅱ组LC术毕腹膜腔喷洒0.5%罗哌卡因30 ml;Ⅲ组为对照组,LC术后腹膜腔内喷洒生理盐水30 ml。麻醉方法均为全凭静脉麻醉。术后6、24、48 h三个时点记录患者术后疼痛视觉模拟评分（VAS）。并观察3组术后使用镇痛药物的例数和肩背痛、恶心呕吐发生率。结果术后6、24、48 h VAS评分Ⅱ组〈Ⅰ组〈Ⅲ组（P〈0.01）。Ⅲ组术后使用镇痛药物的例数（7例）明显高于Ⅰ组和Ⅱ组（2例,0例,P〈0.05）。3组术后肩背痛、恶心呕吐发生率差异无显著性（P〉0.05）。结论经腹膜腔给局麻药镇痛效果明显,术毕给药镇痛效果优于术前给药。     

术后镇痛对剖宫产术后母乳喂养及新生儿的影响

目的 研究剖宫产术后不同镇痛模式对母乳喂养及新生儿神经和适应能力评分(NACS)的影响.方法 120例单胎足月妊娠拟行剖宫产的产妇,采用持续硬膜外麻醉.依术后镇痛用药不同,随机均分为四组.Ⅰ组:0.2%甲磺酸罗哌卡因;Ⅱ组:吗啡80 μg/h+0.2%甲磺酸罗哌卡因;Ⅲ组:芬太尼3 μg/h+0.2%甲磺酸罗哌卡因;Ⅳ组:术后疼痛时采用盐酸哌替啶肌注作为对照.Ⅰ～Ⅲ组均采用镇痛泵,负荷量为0.2%甲磺酸罗哌卡因5 ml.记录术后2、6、24、48 h的疼痛视觉模拟(VAS)评分.观察恶心、呕吐等不良反应发生情况;随访术后24 h内及术后6w母乳喂养情况;记录术后24 h内新生儿NACS.结果 Ⅰ组术后24、48 h VAS评分高于Ⅱ、Ⅲ组(P＜0.05),Ⅳ组术后各时点VAS评分均高于Ⅱ、Ⅲ组(P＜0.05),且术后2、6 h VAS评分高于Ⅰ组(P＜0.05).术后24 h内及术后6 W母乳喂养情况以及术后24 h内新生儿NACS各组差异无统计学意义.结论 吗啡或芬太尼复合甲磺酸罗哌卡因持续硬膜外镇痛均可有效用于剖宫产产妇术后镇痛,对新生儿和母乳喂养无不良影响.     

罗哌卡因对腹腔镜胆囊切除术中术区不同位置镇痛效果的研究

目的:探讨罗哌卡因用于腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)中切口及腹膜内局部浸润、术区表面麻醉的术后镇痛效果。方法:选择全麻下行LC的60例患者,随机、双盲分为4组。A组:不进行任何处理;B组:手术结束前分别于脐部、剑突下、右肋缘下切口注入0.75%盐酸罗哌卡因2 ml;C组:手术结束前分别于脐部、剑突下、右肋缘下切口下周围腹膜注入0.75%盐酸罗哌卡因2 ml;D组:手术结束前分别在脐部、剑突下、右肋缘下皮肤切口及周围腹膜联合胆囊床、肝膈面喷洒0.75%盐酸罗哌卡因2 ml。4组患者的麻醉诱导、维持方法相同,术后均持续监测呼吸、血压、心率、血氧饱和度,记录术后2 h、6 h、12 h、24 h的疼痛视觉模拟评分及术后恶心、呕吐不良反应的发生率。结果:B、C、D组术后2~12 h的疼痛评分低于A组(P<0.05),D组疼痛评分低于B、C两组(P<0.05);术后恶心、呕吐发生率四组差异无统计学意义(P>0.05)。结论:罗哌卡因用于LC具有良好的镇痛效果,同时联合切口、切口周围腹膜及胆囊床、肝膈面表面喷洒罗哌卡因效果更佳,具有良好的安全性。     

罗哌卡因联合地塞米松腹腔内喷洒对腹腔镜胆囊切除术后疼痛的影响

目的探讨罗哌卡因联合地塞米松腹腔内喷洒对腹腔镜胆囊切除术(LC)后疼痛的影响。方法择期全凭静脉麻醉下行LC患者75例,随机均分为三组,建立气腹后向腹腔胆囊床分别喷洒生理盐水30ml(C组)、0.5%罗哌卡因30ml(R组)或0.5%罗哌卡因30ml复合地塞米松10mg(D组)。记录患者术后4、24、48h的切口、内脏、肩部静息和活动时VAS评分、术后恶心呕吐(PONV)的分级和术后追加镇痛药情况。结果 (1)与C组相比,D组患者术后24h和48h的切口静息和活动时VAS评分均明显降低(P<0.01),R组患者仅术后24h的切口静息和活动时VAS评分明显降低(P<0.05或P<0.01);与R组相比,D组患者术后24h和48h的切口静息和活动时VAS评分均明显降低(P<0.01)。(2)与C组相比,R、D组术后4h和24h的内脏静息和活动时VAS评分均明显降低(P<0.01),D组术后24h和48h的肩部静息和活动时VAS评分均明显降低(P<0.01);与R组相比,D组术后48h的肩部静息和活动时VAS评分均明显降低(P<0.05)。结论罗哌卡因联合地塞米松腹腔内喷洒可增强罗哌卡因的术后镇痛效果和延长镇痛时间,但对术后早期(术后4h)切口痛缓解不明显。     

帕瑞昔布钠超前镇痛联合罗哌卡因局部浸润用于腹腔镜胆囊切除术患者术后镇痛的效果

目的 探讨帕瑞昔布钠超前镇痛联合罗哌卡因局部浸润用于腹腔镜胆囊切除术患者术后镇痛的效果.方法 选取拟在全麻下行腹腔镜胆囊切除术的患者150例,年龄41 ～ 63岁,体重55～87 kg,ASA分级Ⅰ级或Ⅱ级,采用随机数字表法,将患者随机分为3组(n=50):帕瑞昔布钠+0.9％生理盐水组(A组)、帕瑞昔布钠+0.5％罗哌卡因组(B组)和帕瑞昔布钠+0.75％罗哌卡因组(C组).于麻醉诱导前30 min静脉注射帕瑞昔布钠40 mg.采用瑞芬太尼和异丙酚双通道靶控输注麻醉.于缝皮前即刻,A组给予生理盐水12 ml,B组和C组分别给予0.5％和0.75％罗哌卡因12 ml行切口周围、皮下、肌肉、腹膜4点浸润麻醉.术后维持VAS评分≤3分,当VAS评分＞3分时,肌肉注射哌替啶75 mg.于术毕、术后2、4、8、12、24h时记录Ramsay镇静评分,记录术后24h内不良反应(恶心呕吐、过敏、呼吸抑制等)的发生情况、哌替啶使用情况、疼痛部位(切口痛、上腹痛、右肩牵涉痛)、切口愈合情况.结果 与A组相比,B组和C组Ramsay镇静评分、恶心和呕吐发生率、哌替啶使用率和总用量及切口痛发生率降低(P＜0.05或0.01);与B组相比,C组哌替啶使用率和总用量及切口痛发生率降低(P＜ 0.05或0.01),Ramsay镇静评分差异无统计学意义(P＞0.05);3组切口愈合情况、上腹痛和右肩部牵涉痛的发生率比较差异无统计学意义(P＞0.05).结论 对于腹腔镜胆囊切除术患者,罗哌卡因局部浸润麻醉可优化帕瑞昔布钠超前镇痛的效果,且采用0.75％罗哌卡因时可产生良好的术后镇痛效果.     

胆囊三角区局部浸润对腹腔镜胆囊切除术患者术后镇痛的安全性及有效性研究

目的:探讨胆囊三角区局部浸润对腹腔镜胆囊切除术(LC)患者术后镇痛的安全性与有效性。方法:选择ASA分级为Ⅰ或Ⅱ级的140例腹腔镜胆囊切除患者,18～64岁,随机分为A组与B组,每组70例。B组于胆囊分离前在胆囊三角区软组织注射1%盐酸罗哌卡因10 mL,A组则予以等容量的0.9%生理盐水。记录两组术后2 h、4 h、6 h、12 h、24 h、48 h静态与动态VAS疼痛评分,以及术后3、6个月静态与动态NRS评分,慢性疼痛发生率。结果:术后2 h、4 h、6 h、12 h、24 h,B组静态与动态VAS评分低于A组,术后48 h动态VAS评分低于A组(P<0.01)。术后139例获得远期随访,术后3个月,A组慢性疼痛发生率为46.38%,内脏痛为33.33%;B组分别为24.29%与14.29%;B组发生率低于A组(P<0.05)。术后6个月,A组慢性疼痛发生率为26.09%,内脏痛为15.94%;B组分别为12.86%与7.14%;B组慢性疼痛发生率低于A组(P<0.05)。结论:罗哌卡因胆囊三角区局部浸润可优化腹腔镜胆囊切除术后患者自控静脉镇痛的效果,有效减轻术后急性疼痛,降低术后慢性疼痛发生率。     

罗哌卡因局部浸润联合舒芬太尼静脉镇痛用于胸科术后镇痛

目的:观察胸外科手术后应用罗哌卡因切口周围浸润麻醉联合舒芬太尼静脉镇痛对术后疼痛的缓解作用.方法:40例胸外科手术患者,随机分2组,Ⅰ组术后使用舒芬太尼,Ⅱ组在Ⅰ组的基础上,于缝皮前切口周围0.375％罗哌卡因浸润麻醉.记录术后VAS评分及肺部并发症的发生率.结果:术后10min、30min、1h、6h,Ⅱ组患者VAS评分低于Ⅰ组,术后Ⅱ组患者要求追加镇痛药的数量低于Ⅰ组,Ⅱ组术后肺部并发症发生率低于Ⅰ组.结论:罗哌卡因局部浸润联合舒芬太尼术后静脉镇痛可显著减轻胸外科皇者术后疼痛,减少肺部并发症的发生率.     

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.