髋部骨折老年患者发生严重术后谵妄的多因素分析

目的探讨髋部骨折老年患者发生严重术后谵妄的危险因素。方法回顾性分析我院骨科2005年1月~2014年12月572例髋部骨折老年患者接受内固定手术的临床资料,对性别、年龄、术前内科合并症、术前卧床时间、手术方式、麻醉方式、手术时间和术中出血量进行单因素分析,多因素logistic回归模型分析髋部骨折老年患者发生严重术后谵妄的危险因素。结果 25例发生严重术后谵妄(25/572,发生率4.4%)。单因素分析结果显示年龄和麻醉方式有统计学差异(P0.05);多因素logistic回归分析显示年龄(OR=1.12,95%CI:1.05~1.19,P=0.001)和全身麻醉(OR=5.03,95%CI:2.10~12.04,P=0.000)是髋部骨折老年患者发生严重术后谵妄的独立危险因素。结论年龄和全身麻醉是髋部骨折老年患者发生严重术后谵妄的独立危险因素。     

帕金森病脑深部电刺激植入术患者术后谵妄的危险因素分析

目的探索帕金森病(PD)患者行脑深部电刺激植入术(DBS)术后谵妄(POD)相关危险因素。方法前瞻性收集2020年10月至2022年5月择期行DBS的PD患者的术前资料、术中资料、术后资料及POD的发生情况。根据术后是否发生谵妄将患者分为谵妄组(52例)及非谵妄组(155例)。对两组患者资料进行组间比较, 并通过logistic回归分析发生POD的危险因素。结果共207例患者纳入研究, 其中有52例(25.1%)患者发生POD。与非谵妄组比较, 谵妄组患者的年龄较大, 术前改良Hoehn-Yahr(H-Y)分级较高, 术后第1天数字分级评分法(NRS)疼痛评分明显较高(均P<0.05)。多因素logistic回归分析显示年龄[校正比值比(OR)1.09, 95%置信区间(CI)1.03～1.16, P=0.002]、术前改良H-Y分级(校正OR 2.67, 95%CI 1.42～5.00, P=0.002)以及术后第1天NRS疼痛评分(校正OR 1.44, 95%CI 1.22～1.70, P<0.001)是DBS POD发生的独立危险因素。结论 PD患者行DBS后谵妄的发...     

非心脏手术患者全麻后早期谵妄的危险因素分析

目的 分析非心脏手术全身麻醉后早期谵妄发生的术前和术中危险因素.方法 2009年6月全身麻醉下接受择期非心脏手术且术后在麻醉恢复室留观患者228例符合研究入选标准,根据CAM-ICU诊断标准分为谵妄组和非谵妄组,收集21个术前因素,14个术中因素,分析与早期术后谵妄相关的危险因素.结果 两组间8个术前变量(年龄、ASA分级、术前血钙、血肌酐、血糖、总胆红素和/或直接胆红素、血清总蛋白和/或白蛋白、恶性疾病)和6个术中变量(手术类型、手术部位、麻醉维持方式、术中总输液量,术中总体液丢失量和手术时间)差异有统计学意义(P<0.05).Logistic回归分析显示吸入麻醉(OR＝6.3,P<0.05)、恶性疾病(OR=3.5,P<0.01)、高ASA分级(OR=3.4,P<0.01)、直接或间接胆红素增高(OR=2.5,P<0.05)以及开放手术(OR＝2.4,P<0.05)是早期术后谵妄的危险因素.结论 吸入麻醉、恶性疾病、高ASA分级、术前直接或间接胆红素增高和开放手术是择期非心脏手术后早期谵妄发生的危险因素.     

非心脏手术老年患者术后谵妄与术前衰弱的关系

目的评价非心脏手术老年患者术后谵妄与术前衰弱的关系。方法收集2019年3月至2022年7月于本院行非心脏手术老年患者, 收集患者年龄、合并疾病、性别、吸烟史、手术类型、术前白蛋白、手术时间、麻醉时间、术后低血压、文化程度、营养状况、ASA分级、术后是否入ICU、术中出血量、术前衰弱状态等病历资料。根据是否发生术后谵妄分为谵妄组和无谵妄组。采用多因素logistic回归分析法筛选术后谵妄发生的危险因素, 绘制受试者工作特征(ROC)曲线分析危险因素对术后谵妄的预测价值。结果谵妄组74例, 无谵妄组321例, 术后谵妄发生率为18.7%。与无谵妄组相比, 谵妄组年龄≥70岁、文化程度初中及以下、营养状况差、ASA分级Ⅲ级、术后入ICU、衰弱患者比例和术中出血量差异有统计学意义(P<0.05)。logistic回归分析结果显示, 年龄、文化程度、营养状况、ASA分级、术中出血量及衰弱均是谵妄的独立危险因素(P<0.05)。术前衰弱预测术后谵妄的ROC曲线下面积及其95%可信区间为0.672(0.605～0.740)。结论术前衰弱是非心脏手术老年患者术后谵妄的独立危险因素, 可在一...     

老年脊柱手术患者术后发生谵妄的危险因素分析

[目的]探讨老年脊柱手术患者术后发生谵妄的危险因素。[方法]回顾分析2014年8月～2016年10月在本院行脊柱内固定手术的老年患者(年龄65岁)共846例的临床资料,其中,术后出现谵妄者92例,男58例,女44例,其中颈椎手术38例,腰椎手术54例,而其余745例患者术后无谵妄。比较两组间性别、年龄、体重指数、吸烟史,术前主要内科合并症、手术部位、手术时间、术中失血量、术后是否发生低氧血症以及术后是否使用止痛泵等,寻找谵妄相关危险因素。并应用Logistic回归进行多因素分析。[结果]单因素分析结果显示年龄、术前血红蛋白值、糖尿病史、脑卒中病史、手术时间及术后低氧血症在谵妄组和非谵妄组之间的差异有统计学意义(P0.05)。多因素logistic回归分析表明术前血红蛋白低(OR=2.026,95%CI 1.229～3.338,P=0.006),高血压病史(OR=1.633,95%CI 1.008～2.646,P=0.046)、慢阻肺疾病史(OR=2.222,95%CI 1.147～4.302,P=0.018)、颈椎手术(OR=1.544,95%CI 1.298～1.994,P=0.048)、手术时间长(OR=1.010,95%CI 1.004～1.016,P=0.002)是术后发生谵妄的独立危险因素。[结论]术前血红蛋白低、高血压病史、慢阻肺疾病史、颈椎手术、手术时间长是术后发生谵妄的独立危险因素。     

老年患者脊柱手术术后谵妄危险因素分析的回顾性研究

目的:探讨老年患者脊柱手术术后谵妄的发生率及相关危险因素。方法:采用回顾性分析2016年1月至2018年11月收治的老年脊柱手术病例436例,根据术后是否发生谵妄分为谵妄组和非谵妄组。记录患者的性别、年龄、身体质量指数,糖尿病史,冠心病史,慢性阻塞性肺疾病史,术前白细胞计数,术前红细胞比容,术前血红蛋白水平,手术方式,手术时间,麻醉时间,美国麻醉医师协会(ASA)评分,心功能分级,术中失血量,术中输血量,术中芬太尼、异丙酚和地佐辛的用量,术后白细胞计数,术后红细胞比容,术后血红蛋白水平,术后电解质(钠离子、钾离子),采用单因素Logistic回归分析有统计学意义的危险因素后进行多元Logistic回归分析进一步探讨独立危险因素。结果:纳入436例中112例老年患者术后出现谵妄,发生率25.68%。谵妄组与非谵妄组在年龄、术前白细胞计数、术前红细胞比容、术后红细胞比容、术后血红蛋白水平、术后钠离子浓度、麻醉时间、ASA评分、心功能评分、术中失血量、术后地佐辛使用量、糖尿病史、冠心病史、慢性阻塞性肺疾病史方面差异有统计学意义(P0.05),通过多因素Logistic回归分析显示年龄、ASA评分、术后地佐辛量、慢性阻塞性肺疾病史是老年患者脊柱手术术后谵妄发生的独立危险因素。结论:患者高龄72岁、ASA评分2分、地佐辛镇痛药物的使用以及患者合并慢性阻塞性肺疾病史是术后谵妄发生的独立危险因素。     

老年股骨转子间骨折术后一年死亡率及其危险因素分析

目的 总结老年股骨转子间骨折患者术后1年的死亡率,并探讨与死亡相关的危险因素.方法 回顾性分析2005年8月至2011年8月杭州地区6家医院经手术治疗且获得随访的1854例老年股骨转子间骨折患者资料,男705例,女1149例;年龄65 ～98岁,平均79.4岁.统计患者术后1年内的死亡率及主要死亡原因,并应用logistic回归模型分析与术后1年死亡相关的危险因素. 结果 术后1年内共有297例患者死亡,死亡率为16.0％ (297/1854).主要死亡原因包括感染93例,心脏疾患38例,神经系统疾患53例,肿瘤63例.Logistic回归分析结果显示:患者年龄[OR=5.053,95％CI(1.517,16.829),P=0.000]、性别[OR=0.376,95％ CI (0.122,1.161),P=0.002]、术前内科合并症[OR =3.236,95％CI (1.553,6.746),P=0.001]、美国麻醉医师协会(ASA)分级[OR=6.057,95％CI (1.968,18.641),P=0.000]、受伤至手术时间[OR=1.928,95％CI(0.979,3.796),P=0.009]和住院时间[OR=3.875,95％CI(0.368,6.542),P=0.001]是术后1年死亡的独立危险因素. 结论 年龄、性别、术前内科合并症、ASA分级、受伤至手术时间及住院时间为老年股骨转子间骨折患者术后1年死亡的独立危险因素.     

老年患者胃癌根治术后急性肾损伤的危险因素

目的 分析老年患者胃癌根治术后急性肾损伤(AKI)的危险因素。方法 回顾性收集接受胃癌根治手术老年患者691例的临床资料,男563例,女128例,年龄≥65岁,ASAⅠ—Ⅲ级。临床资料包括性别、年龄、体重、BMI、ASA分级、吸烟及饮酒史、术前合并症、手术时间、术中用药情况、术中液体出入量、术中尿量、术后住院时间、总住院时间等。根据患者术后是否发生AKI分为两组：AKI组和非AKI组。采用多因素Logistic回归分析发生术后AKI的危险因素。结果 有16例(2.3%)患者发生术后AKI。多因素Logistic回归分析结果显示,合并冠心病(OR=5.587,95%CI 1.355～23.029,P=0.017)和术中尿量减少(OR=0.997,95%CI 0.995～1.000,P=0.023)是老年患者胃癌根治术后AKI的独立危险因素。结论 术前合并冠心病及术中尿量减少是老年胃癌根治术患者术后发生AKI的独立危险因素。     

Stanford A型主动脉夹层患者术后谵妄的危险因素分析

目的分析Stanford A型主动脉夹层患者术后谵妄的危险因素。方法回顾性分析广东省心血管病研究所2012年1月至2014年12月行手术治疗的A型主动脉夹层335例患者的临床资料,其中男280例、女55例,年龄(48.5±10.3)岁。根据患者术后是否出现谵妄,分为谵妄组与对照组,研究术后谵妄发生的独立危险因素。结果全组发生谵妄共169例,发生率为50.4%。单因素及logistic多因素分析结果显示,术前D二聚体水平(OR=2.480,95%CI 1.347~4.564,P0.01)、术中最低平均动脉压(OR=0.667,95%CI 0.612~0.727,P0.01),术后机械通气时间(OR=2.771,95%CI 1.506~5.101,P0.01),术后急性肾功能衰竭(OR=1.911,95%CI 1.065~3.430,P0.05)是Stanford A型主动脉夹层患者术后谵妄的独立危险因素。结论术后谵妄在Stanford A型主动脉夹层术后患者中有较高的发生率。术前D二聚体升高、术中平均动脉压过低、术后机械通气时间延长、合并急性肾功能衰竭的患者,术后谵妄的发生率明显升高。认识上述危险因素,积极干预可控因素,对减少术后谵妄的发生具有积极的意义。     

个体化预测老年髋部骨折患者术后谵妄风险

[目的]通过分析老年髋部骨折患者术后谵妄的相关危险因素,建立并验证个体化预测老年髋部骨折术后谵妄风险的列线图模型。[方法]纳入2013年1月～2018年3月于淄博市中心医院行手术治疗的老年髋部骨折患者257例,收集临床资料。应用单因素及多因素Logistic回归模型,分析老年髋部骨折患者术后谵妄的独立危险因素。应用R软件构建预测老年髋部骨折患者术后谵妄风险的列线图模型,并进行验证。[结果]多因素Logistic回归分析显示,年龄(OR=1.143,95%CI:1.076～1.214)、2型糖尿病(OR=4.591,95%CI:2.14～9.846)、ASA评分III级(OR=4.262,95%CI:1.600～11.352)、ASA评分IV级(OR=5.396,95%CI:1.868～15.583)、全身麻醉(OR=1.281,95%CI:1.066～1.540)及手术时间(OR=1.018,95%CI:1.001～1.035)是老年髋部骨折患者术后谵妄的独立危险因素(P0.05)。对列线图模型进行验证,ROC曲线显示该模型预测老年髋部骨折患者术后谵妄风险的曲线下面积为0.818(95%CI:0.752～0.885);校准曲线为斜率接近于1的直线,Hosmer-Lemeshow拟合优度检验(x~2=8.760,P=0.363)均显示该模型预测老年髋部骨折患者术后谵妄风险具有良好准确度。[结论]本研究基于年龄、2型糖尿病、ASA分级、麻醉方式及手术时间这5项老年髋部骨折患者术后谵妄的独立危险因素,构建的预测老年髋部骨折患者术后谵妄风险的列线图模型,具有良好的区分度与准确度,可为临床个体化防治老年髋部骨折患者术后谵妄提供科学指导。     

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.