重组生长激素对腹部大手术患者血浆蛋白的影响

目的研究重组人生长激素(rhGH)对腹部大手术患者术后代谢、免疫功能和术后并发症的影响。方法回顾性分析腹部大手术患者79人,其中37人为治疗组,42人为对照组。治疗组手术后第2天开始,每天皮下注射思真(重组人生长激素,瑞士雪兰诺公司生产)8U,对照组给予安慰剂(生理盐水),共用7d;分别在治疗前,治疗后3、7、10、14d检测血浆白蛋白、前白蛋白及转铁蛋白水平。记录切口愈合情况及术后并发症情况。结果(1)治疗前,两组白蛋白、前白蛋白及转铁蛋白水平差异无统计学意义(P>0.05);治疗后3d,两组白蛋白水平差异无统计学意义(P>0.05),且均低于治疗前;治疗组前白蛋白、转铁蛋白均高于对照组(P<0.05);治疗后7d,治疗组3项指标均高于对照组。(2)治疗组切口愈合情况明显优于对照组(P<0.05)。(3)治疗组术后并发症发生率明显低于对照组(P<0.05)。结论腹部大手术患者术后应用重组人生长激素可以提高免疫功能,促进切口愈合,减少术后并发症的发生。     

重组人生长激素在肝硬变围手术期应用的临床研究

目的探讨重组人生长激素（rhGH）对肝硬变门静脉高压症患者术后肝功能和营养代谢的影响。方法将2003年2月至2004年1月期间我院收治的48例肝硬变患者随机均分为rhGH组和对照组，2组患者分别于术后第2d给予rhGH或生理盐水，共7d，检测2组患者的白蛋白水平、肝功能及血糖水平。结果rhGH组治疗后第7d起，血浆白蛋白水平明显高于对照组相应时相（P〈0．05）；血ALT、AST明显低于对照组相应时相（P〈0．05）；2组血糖含量随治疗时间延长逐渐降低，治疗后第14d恢复正常，但2组血糖治疗前、后相应时相比较差异无统计学意义（P〉0．05）；2组血浆胆红素水平于治疗前、后相应时相比较差异无统计学意义（P〉0．05）。结论rhGH可促进肝硬变门静脉高压症患者术后蛋白质的合成，纠正低蛋白血症，改善肝功能。     

危重患者术后血浆蛋白和免疫功能的变化及重组人生长激素的治疗作用

目的 观察外科危重患者术后血浆蛋白和免疫功能变化及重组人生长激素（rhGH）的治疗作用。方法 将45例外科危重患者术后随机分为对照组30例和rhGH组15例。两组患者术后治病和营养支持方案相同。rhGH组术后48h开始加用rhGH8U／d肌注,连续7d。观察两组患者血浆蛋白浓度、细胞免疫、体液免疫功能变化及临床结果。结果 两组患者术后血清转铁蛋白、前白蛋白、白蛋白水平;CD3、VD4、VD8、NK活性及CD4／CD8比值均用于正常。rhGH组使用rhGH后第4天血清前白蛋白浓度明显高于治疗前和对照组（P＜0．05）,使用rhGH后第8天血清转铁蛋白、前白蛋白、白蛋白浓度均显著高于对照组（P＜0．05,P＜0．01,P＜0．05）,CD4、NK活性及CD4／CD8比值均明显高于对照组（P＜0．05,P＜0．01,P＜0．05）。结论 术后营养支持加rhGH迅速改善外科危重患者的营养状况和免疫功能。     

胰岛素强化治疗对胃癌术后胰岛素抵抗和血清蛋白的影响

目的探讨胃癌患者术后胰岛素强化治疗对胰岛素抵抗（IR）及血清蛋白的影响。方法将22例行根治性远端胃次全切除术的胃癌患者随机分为对照组（11例）和胰岛素强化治疗组（11例）。分别于术前和术后第1、3、7天测量空腹血糖（FBG）、胰岛素（FINS）和血清白蛋白、血清转铁蛋白（TRF）、前白蛋白（PRE）和视黄醇结合蛋白（RBP），使用稳态模式评估法（HOMA）计算IR指数（HOMA—IR），记录患者住院天数和术后并发症等。结果术后第1、3、7天，对照组和胰岛素强化治疗组IR发生率分别为54．55％和36．36％、9．09％和36．36％、18．18％和0，两组比较差异有统计学意义（P〈0．05）。胰岛素强化治疗组术后第1、3天FBG、FINS和InHOMA—IR明显低于对照组（P〈0．01，P〈0．05）；术后第7天TRF、PRE、RBP高于对照组（P〈0．05）；术后发热时间、抗生素使用时间、肛门排气时间和住院天数明显少于对照组（P〈0．01，P〈0．05），术后并发症发生率明显低于对照组（P〈0．05）。结论胰岛素强化治疗有利于降低胃癌患者术后IR发生率，改善患者的营养状态，防止术后并发症的发生。     

重组人生长激素对肝癌切除术后患者低蛋白血症的调理作用的研究

目的观察重组人生长激素（rhGH）对肝癌切除术后患者低蛋白血症的调理作用。方法40例肝癌切除术后并低蛋白血症患者随机分为治疗组（20例,基础治疗＋低热量肠外营养支持＋rhGH）和对照组（20例,基础治疗＋低热量肠外营养支持）,观察两组患者营养指标、血浆蛋白浓度变化及并发症发生率。结果治疗7d后,治疗组血浆白蛋白、前白蛋白、转铁蛋白明显升高,对照组变化不明显。两组间比较,差异显著（P〈0．01）。治疗组较对照组并发症明显减少。结论低热量营养支持加rhGH联合应用能迅速有效改善肝癌切除术后患者的营养代谢障碍,增强肝脏合成蛋白能力,提高血浆蛋白含量,降低并发症的发生率,改善肝癌切除术后患者的预后。     

乌司他丁对胃癌患者术后肝肾功能保护作用的临床观察

目的观察乌司他丁对胃癌患者术后肝肾功能保护作用的临床疗效。方法选择同期行D2式胃癌根治性手术患者40例，随机分为治疗组（n=20）和对照组（n=20）。治疗组在术后1—3d每天予以生理盐水100ml加乌司他丁20万U静脉滴注，对照组仅给100ml生理盐水静脉滴注。同期检测治疗组和对照组手术前后血红蛋白、血清白蛋白、肝肾功能。结果治疗组术后第5天血红蛋白较术前明显升高（P〈0．05），而对照组血红蛋白无明显改变；治疗组白蛋白仅在术后1d显著下降（P〈0．01），术后3、5d与术前无明显差异，对照组术后1、3、5d白蛋白较术前显著下降（P〈0．01）；两组术后血清ALT水平较术前均有所升高但无统计学意义，但治疗组升高的幅度均小于对照组，治疗组TBIL水平术后第一天明显上升（P〈0．01），随后即下降与术前无差异，对照组TBIL水平无明显改变；治疗组术后1—3d血清Cr水平明显下降与术前相比差异有统计学意义（P〈0．01），而BUN较术后无明显下降，差异无统计学意义（P〉0．05）；对照组术后血清Cr、BUN水平较术前明显升高（P〈0．01），但与治疗组同期相比差异无统计学意义（P〉0．05）。结论乌司他丁可以明显改善胃癌患者的蛋白质代谢异常并对患者的肝肾功能有一定的保护作用。     

严重烧伤患者术后应用重组人生长激素的代谢效应

目的 从代谢角度评估大面积烧伤患者术后应用重组人生长激素（rhGH)的临床价值。方法 选择50例严重烧伤患者,随机等分为生长激素治疗组（rhGH组）和对照组,伤后3d内手术切痂植皮,rhGH组术后每天皮下注射rhGH共10d,动态观察不同时间点的血生长激素、血糖、血胰岛素、抗胰岛素抗体、血胰高血糖素、皮质醇、血浆氨基酸谱、转铁蛋白、转铁蛋白、前白蛋白、总蛋白、电解质及静息能量消耗（REE）和尿中3－三甲基组氨酸（3－MH）水平的变化。结果 2组患者术前血生长激素浓度较正常值降低,差异有显著性意义（t＝2．806,P＜0．05）,应用rhGH后血生长激素浓度较对照组增高,差异有显著性意义（t＝2．014,P＜0．05）;血胰岛素水平2组均高于正常,rhGH组胰岛素水平增高,较对照组差异有显著性意义(t＝3．142,P＜0．05）;胰高血糖素水平、抗胰岛素抗体和皮质醇虽有不同程度的增高,但2组差异无显著性意义;血浆氨基酸水平都低于正常值,rhGH组下降较对照组差异有显著意义（t＝2．714,P＜0．05）;同时尿3－MH排出明显减少（t＝3．044,P＜0．05）;rhGH组血糖、前白蛋白、转移蛋白自应用rhGH后显著高于对照组（t＝2．624－3．044,P＜0．05）;应用rhGH后REE峰值前移,但自应用rhGH第10天开始rhGH组REE值显著低于对照组（t＝2．314,P＜0．05）;rhGH治疗组24h尿中Na^ 、Cl^-较对照组减少（t值分别为2．562＝2．746,P＜0．05）。结论 大面积烧伤患者术后应用rhGH可促进蛋白合成,降低肌肉蛋白分散速率,降低静息能耗,对应激激素无明显影响,有益于危重烧伤后高代谢的调节,但易加重烧伤后的高血糖反应,并可能出现轻度的水钠潴留。     

保留齿状线痔上黏膜套扎外痔切剥术治疗混合痔

目的：评价保留齿状线痔上黏膜套扎外痔切剥治疗混合痔的疗效。方法：将172例混合痔患者采用随机对照单盲法分为2组,治疗组行保留齿状线痔上黏膜套扎外痔切剥术治疗（86例）,对照组行外剥内扎术治疗（86例）。观察2组患者术前、术后1月的症状评分及疗效,观察2组患者的术后并发症及切口愈合时间。结果：治疗后2组症状评分均较治疗前降低（P〈0．05）,2组疗效差异无统计学差异意义（P〉0．05）;2组患者的术后并发症差异无统计学意义（P〉0．05）,但在术后疼痛及切口愈合时间方面治疗组优于对照组,2组差异有统计学意义（P〈0．05）。结论：保留齿状线痔上黏膜套扎外痔切剥术能有效治疗混合痔,减少术后疼痛、缩短愈合时间,为广大肛肠科医师门诊手术提供一种简便安全有效的新治疗方法。     

重组人生长激素联合低热量营养支持对胃肠外科术后氮平衡和血糖的影响

目的观察重组人生长激素（rhGH）联合低热量营养对胃肠外科择期手术后患者的营养支持效果及对血糖的影响。方法将48例择期胃肠外科术后患者随机分为rhGH组和对照组，两组治疗和营养支持方案相同，rhGH组于术后第3-9天给予rhGH。在术前1d、术后3d和10d分别测定两组患者的体质量、血常规、肝肾功能和血浆蛋白指标，并每日检测氮平衡和血糖水平，观察并发症及不良反应，同时记录每日胰岛素用量。结果术后第10天，rhGH组累计氮平衡（13．21g）和血浆纤连蛋白水平[（104．77±19．94）mg/L]优于对照组[-6．88g和（93．03±16．03）mg/L]（P〈0．05）；术后第4天和第6-9天，rhGH组每日氮平衡均优于对照组（P〈0．05）；rhGH组治疗期间血糖水平升高[术后6d（7．68±2．15）mmol／L比（5．95±2．34）mmol／L，P〈0．05]，可为胰岛素有效控制，未发生严重并发症。结论rhGH联合低热量营养支持可以安全地促进蛋白合成和维持正氮平衡。改善营养状况和预后。     

腹腔镜直肠癌根治术围手术期对机体应激、能量代谢及内脏蛋白的影响

目的探讨腹腔镜与开腹直肠癌根治术围手术期c反应蛋白、能量代谢及血清内脏蛋白的差异。方法将45例行直肠癌根治术患者按患者意愿分为腹腔镜组（n=20）和开腹组（n=25），于术前、术后第1天、术后第2天、术后第3天晨检测血C反应蛋白（C-reactive protein，CRP）及内脏蛋白：白蛋白（albumin，ALB）、前白蛋白（prealbumin，PRE）、转铁蛋白（transferrin，TRF）、视黄醇结合蛋白（retinal-binding protein，RbP）的变化，同时应用间接能量测定仪测定静息能量消耗（resting energy expenditure，REE）。结果两组CRP在术后1、2、3d均较术前明显升高（P〈0．01），术后2d达到峰值，腹腔镜组术后CRP明显低于开腹组（P〈0．01）。两组术后1、2、3dREE亦较术前明显升高（P〈0．05，P〈0．01），术后1、3d腹腔镜组明显低于开腹组（P〈0．05）。ALB、PRE、TRF、RbP两组术后均较术前有明显下降（P〈0．01）。术后1d两组各指标差异无显著性（P〉0．05）；术后2d腹腔镜组PRE明显高于开腹组（P〈0．05）；术后3d腹腔镜组4种蛋白指标均明显高于开腹组（P〈0．01）。结论腹腔镜直肠癌根治术较开腹手术创伤小，应激水平低，有利于机体能量代谢及内脏蛋白的恢复，但其同传统开腹手术均可导致术后早期机体营养不良状态的发生。     

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.