电视胸腔镜与开胸手术治疗自发性气胸疗效比较

目的：比较电视胸腔镜手术（video—assisted thoracoscopic surgery，VATS）与开胸手术治疗自发性气胸的疗效。方法：1996年10月～2004年10月将210例自发性气胸按手术方式分为VATS组和开胸组，比较2组在手术时间、术中出血量、术后并发症、术后胸管放置时间、术后住院时间及费用。结果：VATS组手术时间（46±21）min显著短于开胸组（80±37）min（t=-8．209，P=0．000）；术中出血量（41±23）ml显著少于开胸组（175±104）ml（t=-12．947，P=0．000）；术后胸管放置时间（1．8±1．2）d显著短于开胸组（2．4±1．6）d（t=-3．078，P=0．000）；术后住院时间（3．0±1．5）d显著短于开胸组（9．3±3．2）d（t=-18．322，P=0．000）。VATS组手术并发症发生率（8／106，7．5％）显著低于开胸组（33／104，31．7％）（，=19．540，P=0．000）。VATS组无术后复发，开胸组复发2例（1．9％），2组均无死亡。VATS组手术费用（9562±782）元和住院费用（16036±914）元均显著高于开胸组（5165±671）元和（135374-826）元（t=43．692，P=0．000；t=20．775，P=0．000）。结论：电视胸腔镜手术具有术中出血少、手术时间短、术后恢复快和住院时间短的优点，手术效果好，对治疗自发性气胸应作为首选方法，缺点手术费用和住院总费用偏高。     

胸腔镜辅助小切口开胸术和电视胸腔镜手术治疗自发性气胸的比较

目的比较胸腔镜辅助小切口开胸术（VAMT）和电视胸腔镜手术（VATS）治疗自发性气胸的疗效。方法56例按手术方式分为VAMT组（n=34）和VATS组（n=22）。疗效评价指标包括手术时间、术后疼痛评分、术后引流量、住院时间、复发率。结果与VATS组相比，VAMT组手术时间短[（45±12）minvs（80±10）min，t=-11．356，P=0．000）；术后疼痛评分、术后引流量、住院时间和复发率无显著差异（P〉0．05）。结论VAMT和VATS治疗自发性气胸疗效相同，但VAMT比VATS手术时间短。     

电视辅助胸腔镜手术治疗孤立性肺结节临床效果研究

目的探讨电视辅助胸腔镜手术治疗孤立性肺结节临床效果。方法回顾性分析2012年1月~2013年3月我院手术治疗的60例孤立性肺结节患者的临床资料,其中40例患者行VATS手术(VATS组),20例患者行传统开胸手术(开胸组)。比较两组患者孤立性肺结节病理性质、术中出血量、手术时间、胸管留置时间、胸腔引流量、住院时间、住院总费用及术后并发症率。结果两组患者孤立性肺结节的病理特征比较无统计学差异(χ2=6.3442,P=0.5002)。VATS组患者术中出血量、胸腔引流量明显少于开胸组(P0.01或P0.05),手术时间、胸管留置时间及住院时间明显短于开胸组(P0.01),住院总费用与开胸组比较无统计学差异(P0.05)。两组术后并发症发生率比较差异无统计学意义(χ2=3.5337,P=0.0601)。结论电视辅助胸腔镜手术治疗孤立性肺结节损伤小,患者恢复快,效果确切,值得临床推广应用。     

电视胸腔镜手术在纵隔肿瘤切除中的应用

目的探讨电视胸腔镜手术在纵隔肿瘤切除中的临床应用价值。方法回顾性比较我院2007年11月～2011年8月20例电视胸腔镜手术（video—assistedthoracoscopicsurgery,VATS）和20例标准开胸手术（标准开胸组）行纵隔肿瘤切除的开胸时间、开胸出血量、实际手术时间、关胸时间、总手术时间、术后引流量、带管时间、术后住院时间、术后肩关节活动障碍、术后肺部并发症以及术后随访。结果VATS组1例胸腔粘连较重,行胸腔镜辅助小切口手术（video—assistedminithoracomoty,VAMT）。与开胸组相比,VATS组开胸时间短[（12．1±2．0）rainVS．（18．1±2．4）rain,t=-8．589,P=0．000],关胸时间短[（11．4±1．7）min vs．（21．4±2．7）min,t=-14．017,P=0．000],开胸出血量少[（13．2±4．3）mlVS．（25．2±11．4）ml,t=-4．405,P=0．000],术后引流量少[（355．6±110．8）ml VS．（655．6±135．8）ml,t=-7．655,P=0．000],带管时间短[（3．2±0．5）dVS．（4．5±1．1）d,t=-4．812,P=0．000]。2组术后肩关节功能障碍发生率无统计学差异[5％（1／20）VS．25％（5／20）,P=0．182]。40例随访8～12个月,均无肿瘤复发。结论VATS对大多数纵隔良性肿瘤,特别是大部分囊性病变及后纵隔神经源性肿瘤的切除较开胸手术具有明显优势。     

电视胸腔镜与传统开胸肺叶切除术治疗原发性非小细胞肺癌

目的 为了使电视胸腔镜手术(video-assisted thoracoscopic surgery,VATS)在临床中得到更好地应用,探讨电视胸腔镜肺叶切除术(VATS lobectomy)治疗原发性非小细胞肺癌(NSCLC)的临床价值.方法 2007年9月至2008年12月我科手术治疗NSCLC患者76例,其中37例接受电视胸腔镜肺叶切除术(VATS组),男21例,女16例;平均年龄60.4岁;采用胸腔镜辅助小切口肺叶切除术20例,全胸腔镜肺叶切除术17例.39例接受传统开胸肺叶切除术(传统开胸组),男32例,女7例; 平均年龄58.7岁.比较分析两组患者围手术期相关临床和实验室指标的变化.结果 两组患者均无严重并发症和围手术期死亡.VATS组与传统开胸组比较,在切口长度(7.6±1.9 cm vs. 28.5±3.6 cm, t=-31.390,P=0.000),术后杜冷丁用量(160±125 mg vs.232±101 mg,t=-2.789,P=0.007),术后胸腔引流量多于100 ml的天数(4.8±2.5 d vs. 8.1±3.2 d,t=-4.944,P=0.000)和术后住院时间(12.1±3.0 d vs. 15.7±4.7d,t=-3.945,P=0.000)等方面差异有统计学意义;两组在手术时间(t=1.732,P=0.087)、术中出血量(t=-1.645,P=0.105),淋巴结清扫数量(t=-0.088,P=0.930)等方面差异无统计学意义,VATS组的住院总费用略高于传统开胸组,但差异无统计学意义(t=1.303,P=0.197);VATS组术后第1 d血糖(7.2±1.2 mmol/L vs. 8.4±2.2 mmol/L,t=5.603,P=0.000)和白细胞总数(12.7±3.8×109/L vs. 15.1±5.9×109/L, t=5.082,P=0.004)均显著低于传统开胸组,前白蛋白值显著高于传统开胸组(215.0±45.5 mg/L vs.147.3±50.8 mg/L,t=-7.931,P=0.000).结论 电视胸腔镜肺叶切除术可彻底清扫淋巴结,术后创伤较小、急性期反应较低、疼痛轻、恢复较快、住院时间短且不明显增加患者经济负担,在严格选择患者的条件下,可以作为治疗早期NSCLC的一种手术途径.     

全胸腔镜与开胸手术治疗肺隔离症的疗效对比

目的探讨全胸腔镜与开胸手术治疗肺隔离症(pulmonary sequestration,PS)的疗效。方法回顾性分析我院2003年1月~2016年3月手术治疗的48例肺隔离症资料,根据患者经济条件,行全胸腔镜手术18例,开胸手术30例。行肺叶切除或隔离肺切除术。比较2组的术中出血量、术后当日胸腔引流量、术后镇痛时间、胸腔引流时间及术后住院时间。结果与开胸组比较,全胸腔镜组术中出血少[(56.1±50.4)ml vs.(120.0±54.2)ml,t=-3.813,P=0.000],术后当日胸腔引流量少[(160.0±56.0)ml vs.(280.0±65.0)ml,t=-6.100,P=0.000],术后镇痛时间短[(2.4±1.2)d vs.(7.6±1.9)d,t=-9.650,P=0.000],胸腔引流时间短[(2.8±1.0)d vs.(5.7±1.5)d,t=-6.755,P=0.000],术后住院时间短[(6.5±2.6)d vs.(10.1±2.8)d,t=-4.160,P=0.000]。2组手术时间差异无统计学意义(P0.05)。术后发生肺部感染、心律失常、肺不张全胸腔镜组分别为1、0、1例,开胸组为3、2、1例,2组差异无统计学意义(P0.05)。结论全胸腔镜手术治疗肺隔离症较传统开胸手术创伤小,术中出血少,疼痛轻,恢复快,住院时间短,是一种可靠安全的手术方式。     

电视胸腔镜辅助小切口与传统开胸肺叶切除术的比较

目的探讨电视胸腔镜下肺叶切除术的临床效果。方法比较2005年1月至2010年12月105例电视胸腔镜辅助小切口行肺叶切除术（胸腔镜组）与84例常规开胸行肺叶切除术（开胸组）手术及术后并发症发生情况。结果胸腔镜组手术时间（144．77±23．75）min,与开胸组（152．25±19．96）min比较差异无统计学意义（k=-1．331,P=0．188）;胸腔镜组术后住院时间（10．03±2．13）d,明显短于开胸组（12．14±2．46）d（r=-3．650,P=0．001）;并发症的比较：术后漏气的发生率两组比较差异无统计学意义（r=0．021,P=0．886）;胸腔镜组术中出血量（193．71±44．66）ml,明显少于开胸组（228．57±41．96）ml（t=-3．161,P=0．002）;胸腔镜组术后第1天的引流量（234．29±44．97）ml,明显少于开胸组（272．86±40．72）ml（t=-3．526,P=0．001）;术后疼痛程度的比较两组差异有统计学意义（X2=35．080,P=0）;术后上肢活动是否受限两组比较差异有统计学意义（r=20．160,P=0）;胸腔镜组术后拔管时间（7．17±2．12）d,明显短于开胸组（9．00±2．41）d（t=-3．194,P=0．002）。结论电视胸腔镜辅助胸壁小切口肺叶切除术安全、可靠,与开胸手术比较,具有手术出血少、术后引流量少、术后疼痛轻、上肢活动不受限及术后胸管引流时间短等优点。     

传统外科开胸术与电视胸腔镜手术治疗外伤后凝固性血胸的对比研究

目的探讨电视胸腔镜手术(video-assisted thoracoscopic surgery,VATS)在凝固性血胸治疗中的价值。方法应用随机对照研究前瞻性分析2005年7月~2007年7月间开展的VATS和传统开胸手术治疗凝固性血胸各31例,比较临床病理生理参数。结果2组性别、年龄、开放伤、伤侧及合并伤发生率无显著差异。与开胸组相比,VATS组手术时间短[(52.1±24.4)minvs(120.2±47.2)min,t=-7.136,P=0.000],术中出血少[(137.1±14.6)mlvs(203.2±53.4)ml,t=-6.648,P=0.000],术后引流量少[(181.3±37.9)mlvs(253.9±64.0)ml,t=-5.435,P=0.000],术后引流时间短[(1.7±0.7)dvs(4.8±1.8)d,t=-8.937,P=0.000],术后住院时间短[(12.6±2.4)dvs(18.0±8.9)d,t=-3.262,P=0.002]。2组并发症发生率无显著差异(0例vs1例,χ2=0.000,P=0.000)。结论VATS治疗凝固性血胸安全有效,有一定的推广价值。     

完全电视辅助胸腔镜与常规开胸行二尖瓣置换术的临床效果比较

目的比较完全电视辅助胸腔镜与常规开胸行二尖瓣手术临床疗效的优缺点。方法 2012年3月~2013年10月,238例单纯二尖瓣病变分别经完全电视辅助胸腔镜(胸腔镜组,n=110)与常规开胸(常规开胸组,n=128)二尖瓣置换术。比较2组患者手术时间、升主动脉阻断时间、心肺转流时间、术后机械呼吸时间、监护室停留时间、术后住院时间和胸液引流量,术后半年复查二尖瓣返流情况。结果胸腔镜组与常规开胸组手术时间[(256.2±28.5)min vs.(251.2±30.0)min,t=1.312,P=0.191],升主动脉阻断时间[(40.0±2.7)min vs.(39.4±2.7)min,t=1.709,P=0.089],心肺转流时间[(74.2±4.1)min vs.(73.7±4.9)min,t=0.846,P=0.399]无显著性差异。胸腔镜组术后机械呼吸时间(716.4±79.1)min,明显短于常规开胸组(811.9±58.8)min(t=-10.657,P=0.000);监护室停留时间(26.2±3.6)h,明显短于常规开胸组(29.3±4.7)h(t=-5.640,P=0.000);术后住院时间(9.6±1.2)d,明显短于常规开胸组(10.9±2.5)d(t=-4.982,P=0.000);胸液引流量(328.1±83.2)ml,明显少于常规开胸组(561.3±143.9)ml(t=-14.978,P=0.000)。2组患者无死亡,术后半年复查,二尖瓣均无明显返流。结论完全电视辅助胸腔镜下行二尖瓣置换术给患者造成的手术创伤明显轻于常规开胸手术。     

全胸腔镜肺叶切除与开胸肺叶切除对非小细胞肺癌病人术后化疗的影响对比

目的 对比全胸腔镜(VATS)肺叶切除术与开胸肺叶切除术对非小细胞肺癌病人术后化疗情况的影响.方法 回顾性分析2005年4月至2009年6月102例行肺叶切除并术后化疗的非小细胞肺癌病人资料.按手术方式分为VATS组和开胸组,总结病人术前一般资料、手术相关指标和化疗的完成情况.结果 VATS组45例,开胸组57例;两组病人年龄,术前肺功能、合并症,术后分期、肿瘤大小、胸腔引流时间、住院天数等差异无统计学意义.VATS组在术中出血、手术时间、术后并发症略少.与开胸组比较,VATS组完成3个或3个以上疗程的术后化疗的病人比例(86.7%对70.2%,P=0.048)、按期全剂量、全疗程完成化疗病人比例(48.9%对29.8%,P=0.049)均高于开胸组,因化疗不耐受而减量化疗比例低于开胸组(0对10.5%,P=0.033).两组间术后开始化疗的时间、化疗毒性反应级别差异无统计学意义.结论 胸腔镜肺叶切除术后病人有更好的化疗依从性,按计划完成化疗者比例高.     

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.