不停跳冠状动脉旁路移植术中血流动力学的改变及处理

目的分析不停跳冠状动脉旁路移植（OPCAB）术中血流动力学变化特点,探讨维持血流动力学稳定的管理措施。方法2005年1月至8月连续100例病人接受OPCAB。共完成旁路血管313支,平均（3．1±0．7）支。术中监测每支冠脉远端吻合时的血流动力学指标,分析其变化特点。术中采取了心包悬吊、心脏位置改变、确保吻合口质量及合理应用血管活性药物等一系列管理措施,维持术中血流动力学稳定。结果前降支（LAD）远端吻合时,血流动力学变化较小。重建LAD血供后,平均动脉压（MAP）、左室运动指数（INSWI）、每搏输出指数（SI）、心排指数（CI）等指标升高。侧壁、下壁冠脉回旋支（LCX）、后降支（PDA）、左室后支（PLB）、钝缘支（OM）的远端吻合时,血流动力学波动大,心率（HR）、中心静脉压（CVP）明显升高,MAP、CI、右室舒张末容积（RVEDV）、LVSWI、右室做功指数（RVSWI）有明显下降。术毕CI明显改善。全组无死亡,除1例术中因血流动力学持续不稳定改为体外循环下手术和术后2例发生二次开胸止血外,无其他严重并发症,心绞痛缓解,心功能明显改善,均顺利出院。结论OPCAB术中,LAD远端吻合时血流动力学波动小,重建血供后,心肌收缩功能改善。侧壁、下壁冠脉远端吻合时血流动力学波动大。术中采用心包悬吊、心脏体位改变、保证吻合口质量及血管活性药物的合理应用等一系列措施是确保手术成功的关键。     

非体外循环冠状动脉旁路移植术的手术策略对术中血流动力学的影响

目的 研究非体外循环冠状动脉旁路移植术(CABG)的术中手术策略在吻合不同部位靶血管时对血流动力学的影响,探讨非体外循环CABG术中稳定血流动力学的措施.方法 2005年3月至2007年3月进行手术治疗的67例冠状动脉粥样硬化性心脏病患者,男性45例,女性22例,年龄44～81岁,均为严重三支病变.所有患者均先作左胸廓内动脉一前降支(LIMA-LAD)吻合,再作钝缘支(OM)及后降支(PDA)的序贯吻合.根据吻合的顺序不同将患者分为三组:组Ⅰ吻合顺序为PDA-OM-主动脉(Ao),共22例;组Ⅱ吻合顺序为Ao-PDA-OM,共14例;组Ⅲ为Ao-OM-PDA,共31例.以LIMA-LAD吻合前的血流动力学指标为基础值,在LAD吻合时及吻合后、PDA吻合时、OM吻合时各时间点测定血流动力学指标,并与基础值相比较.结果 67例患者均顺利施行了非体外循环CABG,无手术死亡.行LIMA-LAD吻合时,各项血流动力学指标变化不显著.LIMA-LAD完成后,各项指标显著改善.吻合OM时,组Ⅰ、组Ⅲ的心率(HR)、中心静脉压(CVP)显著升高(P＜0.05),平均动脉压(MAP)、心指数(CI)、左室做功指数(LVSWI)及右室做功指数(RVSWI)均显著降低(P＜0.05),但组Ⅱ上述指标变化均不显著(P＞0.05).吻合PDA时,组Ⅰ、组Ⅱ的HR、CVP均显著升高(P＜0.05),MAP、CI、LVSWI及RVSWI均显著降低(P＜0.05),但组Ⅲ上述指标变化不显著(P＞0.05).结论 先吻合桥血管的近端,再序贯吻合靶血管,这样的手术策略有利于非体外循环CABG时完成显露、吻合困难的OM、PDA部位的手术.     

非停跳冠脉搭桥术中病人心脏形态和功能的变化

目的观察非停跳冠脉搭桥术（OPCAB）中病人心脏形态和功能的变化。方法择期行OPCAB病人30例，ASAll或Ⅲ级。麻醉诱导后气管插管，经右侧颈内静脉放置CCO／SVO，／CEDV导管，连续监测血液动力学参数，经口放人多平面经食管彩色超声诊断仪探头，监测食管超声心动图（TEE）参数。分别于打开心包时（基础值）、前降支（LAD）搭桥、回旋支（LCX）搭桥、右冠状动脉（RCA）搭桥、吻合完毕时测定TEE参数及血液动力学参数。结果与基础值比较，LAD搭桥时二尖瓣血流E波减速时间（DL）缩短，经过二尖瓣口的左心流量（Q；）降低，MAP、HR下降，CVP升高；LCX搭桥时左心室舒张末直径（LVEDD）、右心室舒张末直径（RVEDD）、三尖瓣环直径（TVD）、射血分数（EF）、Q，、经过中尖瓣口的右心流量（Q2）、左心室流出道舒张变化率[（DDL—SDL）／DDL]、三尖瓣血流E／A比值（E2／A2）、TVD降低，二尖瓣血流E／A比值（E1／A1）升高，DL、三尖瓣血流E波减速时间（DT2）缩短，HR、MAP、每搏量（sV）、混合静脉血氧饱和度（蹄01）、右心室舒张末容积（RVEDV）、右心室收缩末容积（RVESV）、右心室射血分数（RVEF）、右心室舒经末容积指数（RVEDVI）降低，CVP升高；RCA搭桥时LVEDD、LVESD、二尖瓣环直径、Q，、E2／A2、HR、MAP、平均肺动脉压、SV、SvO2、RVEVD、RVESV、RVEF、RVEDVI降低，CVP升高，DT1缩短，右心室流出道舒张直径（RVOTDD）、右心室流出道收缩直径（RVOTSD）增加（P＜0．05）；吻合完毕时各指标恢复到基础值水平（P＞0．05）。心脏形态学表明LAD、RCA搭桥时以左心室直接受压为主，LCX搭桥时以右心室受压为主。结论在OPCAB中LAD、LCX、RCA搭桥时左右心室同时受压，但左右心室受压的程度随着搭桥血管、心脏位置不同而不同；心功能呈一过性的损害，在完成血管搭桥后均能恢复。     

非体外循环冠状动脉旁路移植术的血流动力学研究

目的：分析非体外循环冠状动脉旁路移植术中血流动力学的变化。方法：2000年6月至2001年1月，连续32例病人接受非体外循环冠状动脉旁路移植术，术中、术后对各吻合血管的血流动力学指标进行持续监测。全组完成前降支吻合32例、右冠状动脉26例、回旋支28例、对角支8例。结果：本组死亡例。行前降支冠状动脉吻合时血流动力学指标无明显变化。右冠状动脉吻合时影响右心功能。回旋支及对角支冠状动脉吻合时对血流动力学有明显的影响，导致平均肺动脉压（MPAP）、肺毛细血管楔压（PAWP）、中心静脉压（CVP）明显升高，每搏指数（SVI）及左室每搏功指数（LVSWI）有明显下降；心排指数（CI）有一定的下降趋势。行主动脉近心端吻合时尽管已无心脏搬动，但MPAP、SVRI及肺循环阻力指数（PVRI）仍较诱导后有明显升高，CI有明显下降。术毕及术的2、6、16h各血流动力学指标趋于正常，CI有明显改善。结论：非体外循环冠状动脉旁路移植行前降支及右冠状动脉吻合时对血流动力学影响较小，回旋支及对角支冠状动脉吻合时对血流动力学有明显的影响，术毕及术后2、6、16h各血流动力学指标趋于正常，心脏功能有明显改善。     

不同射血分数患者非体外循环冠状动脉旁路移植术中右心功能变化

目的研究不同射血分数患者非体外循环冠状动脉旁路移植术(OPCABG)术中右心功能变化规律。方法选择50例择期行OPCABG的患者,ASAⅡ或Ⅲ级,其中EF≥50%组30例,EF≤35%组20例,麻醉诱导后放置肺动脉导管,分别记录开心包后(基础值)、前降支(LAD)搭桥、回旋支(LCX)搭桥、后降支(PDA)搭桥及关胸骨后的CVP、平均肺动脉压(MPAP)、肺动脉楔压(PAWP)、心脏指数(CI)、右室射血分数(RVEF)、右室舒张末容积指数(RVEDVI)等。结果与基础值比较,LAD、LCX、PDA搭桥两组CVP、MPAP、PAWP明显升高(P<0.05);LCX、PDA搭桥两组CI、RVEF明显降低(P<0.05);而EF≥50%组RVEDVI明显降低、EF≤35%组RVEDVI明显升高(P<0.05)。与EF≤35%组比较,LCX、PDA搭桥、关胸后EF≥50%组RVEF明显升高(P<0.05);而LCX、PDA搭桥EF≥50%组RVEDVI明显降低(P<0.05)。结论在OPCABG术中行LCX和PDA搭桥期间可见右心功能受限,而不同射血分数患者之间右心功能变化规律有不同。     

尼卡地平联合艾司洛尔对冠状动脉搭桥期间全身和组织氧合的影响

目的探讨尼卡地平联合艾司洛尔(N E)是否对非心肺转流(CPB)冠状动脉搭桥术(OPCAB)期间全身和组织氧合具有保护作用。方法选择20例行OPCAB病人,随机分为尼卡地平联合艾司洛尔组(N E组)和硝酸甘油联合艾司洛尔组(X E组),每组10例。麻醉诱导后,输注N E或X E混合液维持MAP 70~80 mmHg。于麻醉诱导后(T1)、搭桥前(T2)、前降支(LAD)搭桥(T3)、后降支(PDA)搭桥(T4)、回旋支(LCX)搭桥(T5)、搭桥结束(T6)和术毕(T7)测定血液动力学、动脉血乳酸(Lac)含量和胃粘膜二氧化碳压力(PgCO2)等参数,计算氧供(DO2)、氧耗(VO2)和胃粘膜pH(pHi)。结果OPCAB期间,N E组病人的心指数(CI)明显高于(P<0.05)或等于基线水平;而X E组病人则轻度下降。N E组病人在T4、T5,X E组病人从T3至T6的心脏每搏量指数(SVI)均明显下降(P<0.05);N E组病人的周围血管阻力指数(SVR1)明显下降,且明显低于X E组病人(P<0.05);两组病人的HR术中均明显增加(P<0.05)。输注N E混合液后DO2均高于或等于基线水平(P<0.05),血Lac含量处于正常范围;X E组病人的DO2搭桥期间均下降,特别是LCX搭桥时(P<0.05),而且血Lac含量显著升高并超出正常范围(P<0.05)。N E组病人OPCAB期间的pHi均高于7.35,而X E组病人从T4至T7则低于7.35。结论尼卡地平联合艾司洛尔配方对OPCAB期间全身和组织氧合具有保护作用。     

60岁以上男性多支冠状动脉病变旁路移植术后血流动力学研究

目的研究60岁以上男性多支冠状动脉病变旁路移植术后早期血流动力学的变化。方法对20例60岁以上男性体外循环下多支冠状动脉病变旁路移植术患者术前及术后血流动力学变化进行监测。结果术后2～6小时心脏指数（CI）、每搏指数（SVI）明显降低（P〈0.05）,肺循环指数（PVRI）、体循环指数（SVRI）明显升高（P〈0.05）;24～48小时后心功能明显改善,CI、左室每搏做功指数（LVSWI）明显增高（P〈0.05）。结论多支冠状动脉病变旁路移植术后早期CI明显下降,术后24小时内应有效降低体循环阻力,以降低左心室后负荷并以此增强左心室收缩功能及心排出量     

急诊冠状动脉旁路移植术一例

患者男,63岁.因持续心绞痛入院,心电图诊断急性前壁心肌梗死,临床上血流动力学不稳定.急行冠状动脉造影示冠状动脉3支病变,即左前降支(LAD)狭窄95%,左回旋支主干(LCX)90%,对角支(Diag)95%以及右冠状动脉(RCA)两处狭窄均大于90%.心尖部心肌运动减弱.直接送入手术室,术中见心尖部心肌颜色变暗,心肌运动消失.手术在全身麻醉低温体外循环及间断灌注4∶1冷血心脏停搏液下进行.建立低温体外循环后,用大隐静脉行LCX,Diag和RCA血管移植,左胸乳内动脉与LAD吻合.开放升主动脉后,心脏自动复跳,顺利停机.术后心绞痛症状消失,心电图示心肌缺血改善.术后10天恢复出院.     

OPCAB即时与关胸时乳内动脉桥血流的对比研究

目的　使用即时超声血流探测仪对比观察非体外循环冠状动脉旁路移植术 (OPCAB)术中左乳内动脉 (LIMA)桥吻合完毕当时 (早期 )与关胸时 (晚期 )桥血流变化规律。方法　 2 0 0 2年 1月至 8月 ,对 6 5例OPCAB病人进行了早期与晚期动脉桥血流的对比研究。其中男 5 0例 ,女 15例 ;年龄 47～ 75岁 ,70岁以上病人 19例 ( 2 9 2 %)。病人均为不稳定型心绞痛 ,其中冠状动脉三支病变 32例 ( 49 2 %) ,二支病变 2 6例 ( 40 0 %) ,单支病变 7例 ( 10 8%)。OPCAB术中常规使用LIMA与左前降支 (LAD)吻合。于LIMA与LAD吻合完毕和手术结束关胸前 ,用即时血流测量仪 (transit timeflowmeter)直接测量并记录LIMA桥血流波形、平均流量、舒张期流量、收缩期流量、搏动指数及平均动脉压。结果　两组平均动脉压差异无显著性 (P =0 0 5 ) ;LIMA桥平均血流量早期 ( 2 9 91± 3 32 )ml min显著高于晚期 ( 2 5 12± 2 5 6 )ml min ,P =0 0 3;舒张期流量早期 ( 5 9 2 6± 5 2 1)ml min与晚期 ( 5 4 36± 4 2 7)ml min差异无显著性 ,P =0 0 8;收缩期流量早期 ( 12 98± 1 6 4)ml min显著高于晚期 ( 6 17± 1 93)ml min ,P <0 0 0 1;搏动指数早期 2 6 9± 0 12明显小于晚期 3 36± 0 37,P =0 0 2。结论　LIMA与LAD吻合     

非体外循环冠状动脉搭桥术术后早期心脏功能评价

目的 评价非体外循环冠状动脉搭桥术（OPCAB）术后早期心脏功能。方法 OPCAB组42例，体外循环冠脉搭桥术组63例（对照组），对比两组血浆心肌酶水平和心电图变化，利用Wwan-Ganz导管分析术中和术后血液动力学变化趋势，并评价早期临床效果。结果 两组临床资料无差别。OPCAB组中CK、CK－MB、AST、LDH的平均血浓度在术后当天、术后1d、3d和术后1周均正常，而对照组则有升高。OPCAB组心电图阳性变化数目较对照组少见。血液动力学指标显示，OPCAB组的心排指数、每搏输出量指数和左室作功能指数匀较对照组恢复迅速，而肺动脉楔压和中心静脉压水平偏低。OPCAB组近期临床效果也较对照组优越。结论 OPCAB组术后早期心脏功能优于体外循环下的冠状动脉搭桥术，提示OPCAB手术心肌保护效果好，血管吻合的精确性也令人满意。     

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.     

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.     

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.     

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.     

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.     

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.