雷米芬太尼分别复合丙泊酚与异氟醚用于阻塞性睡眠呼吸暂停综合征手术的麻醉效果

目的比较雷米芬太尼、丙泊酚全凭静脉麻醉与雷米芬太尼、异氟醚静吸复合麻醉用于阻塞性睡眠呼吸暂停综合征手术时的麻醉效果。方法择期行悬雍垂、鄂咽成形术或鄂咽成形术患者40例,性别不限,年龄30～55岁,ASA分级Ⅰ或Ⅱ级,按照随机数字表法,将其分为2组(n=20):雷米芬太尼、丙泊酚全凭静脉麻醉组(A组)和雷米芬太尼异氟醚静吸复合麻醉组(B组)。麻醉诱导完成后,A组靶控输注丙泊酚4～8 mg/(kg·h),B组吸入0.5%～1%异氟醚,两组持续静脉输注雷米芬太尼0.2～0.3 g/(kg·min)。记录患者诱导前即刻(T1)、诱导完成后即刻(T2)、插管后即刻(T3)以及手术开始20 min时(T4)的血流动力学变化。记录自主呼吸恢复时间、气管导管拔除时间和PACU停留时间。记录术后呛咳、躁动和恶心呕吐等不良反应的发生率。结果与B组比较,T4时A组BP和HR显著降低(P0.01),A组自主呼吸恢复时间、拔管时间和PACU停留时间均显著缩短(P0.05),A组剧烈呛咳和躁动发生率显著降低(P0.01)。结论雷米芬太尼复合丙泊酚更适合用于阻塞性睡眠呼吸暂停综合征手术的麻醉。     

麻醉方式对鼻内镜手术鼻黏膜血流及术野的影响

目的 研究相同麻醉深度下雷米芬太尼-丙泊酚静脉麻醉及异氟醚吸入麻醉对血流动力学、鼻黏膜血流及术野清晰度的影响.方法 择期鼻内镜手术(ESS)患者30例,随机均分为雷米芬太尼-丙泊酚静脉麻醉组(T组)及氧化亚氮-氧-异氟醚吸入麻醉组(Ⅰ组).观察两组麻醉前、麻醉后10 min BP、HR、鼻黏膜血流灌注量(PU)、运动的血细胞浓度(CMBC)、血细胞平均运动速率(Ⅴ)及术野清晰度.结果 T组麻醉后10 min BP低于、HR慢于、PU、Ⅴ低于麻醉前(P<0.05);Ⅰ组麻醉后10 min BP低于麻醉前(P<0.05),但HR快于麻醉前(P<0.05),PU及Ⅴ麻醉前后差异无统计学意义.T组术野清晰度优于Ⅰ组(P<0.05).结论 与异氟醚吸入麻醉相比,雷米芬太尼-丙泊酚静脉麻醉可降低鼻黏膜血流,提高术野清晰度,适于ESS.     

七氟醚不同吸入方式对瓣膜置换术患者血清肌钙蛋白-T及炎性细胞因子的影响

目的观察七氟醚不同吸入方式对心肺转流(CPB)下心脏瓣膜置换术中血清肌钙蛋白T(cTnT)和炎性细胞因子IL-6、IL-8浓度的影响,探讨不同七氟醚处理方法的心肌保护作用及其机制。方法 52例拟行全身麻醉下CPB心脏瓣膜置换术的患者,随机均分为:七氟醚预处理组(S1组)、七氟醚后处理组(S2组)和七氟醚预处理联合后处理组(S3组)和对照组(C组)。S1组:麻醉诱导后连续吸入1%七氟醚至主动脉阻断;S2组:主动脉、腔静脉开放后连续吸入1%七氟醚至手术结束;S3组:麻醉诱导后连续吸入1%七氟醚至主动脉阻断时停止,主动脉、腔静脉开放后再连续吸入1%七氟醚至手术结束;C组在整个麻醉手术期间不吸入七氟醚。于麻醉诱导后即刻(T0)、主动脉开放后2h(T1)、6h(T2)、12h(T3)和24h(T4)分别采集桡动脉血3ml,测定cTnT、IL-6和IL-8浓度。结果与T0时比较,T1~T3时S1组、S2组和S3组血清cTnT、IL-6和IL-8浓度明显升高(P0.05)。与C组比较,T1~T3时S1组、S2组和S3组血清cTnT、IL-6和IL-8浓度明显降低(P0.05);而T4时S1组、S3组血清cTnT浓度和S1组、S2组和S3组血清IL-6、IL-8浓度明显降低(P0.05)。结论七氟醚预处理、七氟醚后处理和七氟醚预处理联合后处理三种方式均可有效显减轻瓣膜置换术中心肌缺血-再灌注损伤,心肌保护作用相近,机制可能与抑制全身炎症反应有关。     

七氟醚后处理对瓣膜置换术中血清肌钙蛋白T及IL-6、IL-8浓度的影响

目的 观察七氟醚后处理对瓣膜置换术中血清心肌损伤标志物肌钙蛋白T(cTnT)及白细胞介素( IL)-6、IL-8浓度的影响,探讨其心肌保护作用.方法 24例拟行单瓣膜置换术的风湿性心脏病患者,随机均分为七氟醚组(S组)和对照组(C组).两组采用相同麻醉及体外循环方法.S组在主动脉开放后即刻吸人5％七氟醚,呼气末浓度达1 MAC后调整吸入浓度并维持1 MAC 10min,C组不吸入七氟醚.麻醉后即刻(T1)和主动脉开放后1 h(T2)、2 h(T3)、4 h(T4)经桡动脉采血3ml,分别用电化学发光法和放射免疫法测定血清cTnT和IL-6、IL-8浓度.结果 两组T2～T4时血清cTnT、IL-6、IL-8浓度均明显高于T1时,但S组明显低于C组(P＜0.05).结论 七氟醚后处理能明显减轻瓣膜置换术中心肌缺血-再灌注损伤,其机制可能与抑制全身炎症反应有关.     

异氟醚预处理对心脏瓣膜置换术病人血清一氧化氮与肌钙蛋白Ⅰ的影响

目的探讨异氟醚预处理对心肌缺血-再灌注损伤的保护效应及机制。方法择期行心脏瓣膜置换术的风湿性心脏瓣膜病病人32例,随机分为异氟醚组和对照组,每组16例。异氟醚组以1.5%~2%异氟醚吸入复合芬太尼维持麻醉,心肺转流(CPB)开始前洗脱10min,CPB后以芬太尼维持麻醉;对照组以芬太尼维持麻醉。分别于麻醉前(T0)、CPB前(T1)、CPB30min(T2)、术后8h(T3)、24h(T4)抽取中心静脉血测定一氧化氮(NO)、NO合酶(NOS)与心肌肌钙蛋白I(cTnI)浓度。结果两组病人T0时NO、NOS与cTnI浓度差异无显著意义;异氟醚组T1、T2时NO、NOS浓度明显高于对照组(P<0·05),T3、T4时cTnI浓度明显低于对照组(P<0·05)。结论异氟醚具有心肌预适应作用,其机制可能与增加NO释放有关。     

不同麻醉方式对不停跳冠状动脉旁路移植术患者应激反应的影响

目的比较三种不同麻醉方式对不停跳冠状动脉旁路移植术(OPCABG)患者应激反应的影响。方法ASAⅡ~Ⅲ级行OPCABG患者54例,随机分三组:丙泊酚靶控输注(TCI)组(Ⅰ组)、异氟醚组(Ⅱ组)、丙泊酚TCI复合异氟醚吸入组(Ⅲ组),每组18例。在麻醉诱导前(T0)、切皮后(T1)、劈胸骨后(T2)、手术结束时(T3)观察HR、MAP,在T0、T2、T3及术后18 h(T4)测定血糖(Glu)、血浆肾上腺素(E)、血清促肾上腺皮质激素(ACTH)、皮质醇(Cor)及白细胞介素-6(IL-6)浓度。结果Ⅱ组在T1、T2及T3时的HR均明显高于Ⅰ组和Ⅲ组(P<0.05)。三组患者T3时Glu、血清ACTH、Cor及IL-6均明显高于T0时(P<0.05);而Ⅲ组患者Glu、血浆E、血清ACTH、Cor及IL-6都明显低于Ⅰ组和Ⅱ组(P<0.05)。结论丙泊酚TCI复合异氟醚吸入维持OPCABG麻醉能明显地抑制手术引起机体的应激反应。     

异氟醚与咪唑安定或丙泊酚联合应用对心肌缺血-再灌注期心肌肌钙蛋白Ⅰ的影响

目的　观察异氟醚与咪唑安定或丙泊酚联合应用对心肺转流 (CPB)心内直视手术心肌缺血 /再灌注期血清心肌肌钙蛋白Ⅰ (cTnⅠ )的影响。方法　 5 0例先心、房或室间隔缺损择期行心内直视手术患者 ,随机分为五组 ,每组 10例。Ⅰ组泵注咪唑安定 2 0～ 4 0mg·kg-1·h-1维持麻醉 ;Ⅱ组丙泊酚 0 2～ 0 4mg·kg-1·h-1;Ⅲ组转流前、主动脉开放后持续吸入 0 8～ 1 3MAC异氟醚 ;Ⅳ组转流前吸入异氟醚同Ⅲ组 ,主动脉阻断后泵注咪唑安定同Ⅰ组 ;Ⅴ组转流前同Ⅲ组 ,主动脉阻断后微泵静注丙泊酚同Ⅱ组。分别在术前、停CPB后 30分钟、2小时和术后 2 4小时取中心静脉血 ,测定血清cTnⅠ水平 ,并观察开放主动脉后心脏复跳情况。结果　与术前比较 ,五组患者停CPB后各时点cTnⅠ明显升高 (P <0 0 1)。各组术后 2 4小时值与停CPB 2小时值比较已显著下降 (P <0 0 1) ,Ⅰ组与其他各组比较升高更为显著 (P <0 0 1)。异氟醚与咪唑安定或丙泊酚联合应用 ,与异氟醚组各时点值比较 ,血清cTnⅠ未见明显降低。Ⅳ组与Ⅴ组间相比也无显著差异。各组心脏自动复跳率无差异。结论　丙泊酚减轻心肌缺血再灌注损伤的作用明显强于等效剂量的咪唑安定 ;异氟醚具有明显的心肌保护作用 ;异氟醚和丙泊酚或咪唑安定合用 ,cTnⅠ水平接近异氟     

氟马西尼对异氟醚麻醉后清醒恢复的影响

氟马西尼是苯二氮类药物的特异性拮抗药 ,用于安定类药物的催醒已有多年历史。而且文献报道氟马西尼对常用吸入麻醉药氟烷、安氟醚、异氟醚麻醉后也有催醒作用[1 ] 。我们对此进行临床研究。资料与方法一般资料　选用 5 6例 1 7～ 4 8岁整形外科病人 ,男 1 5例 ,女 4 0例 ,ASAⅠ级 ,择期在气管插管全身麻醉下行整形外科手术。病人被随机分为三组 ,观察Ⅰ组 (n =2 1 )和对照组 (n =1 8) :手术结束前 1h停用静脉麻醉药 ,单纯吸入异氟醚、氧化亚氮加氧气到手术结束。观察Ⅱ组 (n =1 7) :手术结束前 1h停用丙泊酚、芬太尼和异氟醚 ,静脉给咪…     

雷米芬太尼复合丙泊酚与芬太尼复合异氟醚在实施心脏手术快通道麻醉的比较

目的比较雷米芬太尼复合丙泊酚与芬太尼、丙泊酚复合异氟醚用于不停跳心脏手术患者麻醉的应激激素及血流动力学变化。方法26例患者随机均分为雷米芬太尼复合丙泊酚(RP组)和芬太尼复合异氟醚(FI组)两组。分别记录不同时点HR、MAP和血糖(Glu)数值,同时观察相应时点血浆皮质醇(Cor)及促肾上腺皮质激素(ACTH)反应。结果两组患者各观察点血流动力学及应激激素变化组间比较差异无统计学意义。两组患者血浆Cor、ACTH、Glu在心肺转流(CPB)后15min、停CPB后10min与诱导前比较差异有统计学意义(P<0.01),RP组患者术后清醒时间及拔管时间明显早于FI组(P<0.01),但ICU留观时间组间比较差异无统计学意义,且RP组术后疼痛发生率高于FI组(P<0.05)。结论雷米芬太尼复合丙泊酚实施不停跳心内直视手术麻醉,可维持术中血流动力学平稳,停药后清醒快,符合快通道心脏手术麻醉要求,但应加强术后镇痛。     

比较丙泊酚与七氟醚麻醉对梗阻性黄疸患者苏醒和术后恶心呕吐的影响

目的 比较丙泊酚靶控输注(TCI)与七氟醚吸入麻醉对梗阻性黄疽患者苏醒时间和术后恶心呕吐(PONV)的影响.方法 梗阻性黄疸患者60例,ASA Ⅰ或Ⅱ级,随机均分为丙泊酚组(P组)和七氟醚组(S组).术中均维持脑电双频指数(BIS)在40～55.记录患者麻醉前(T1)、气管插管后即刻(T2)、手术开始即刻(T3)及手术结束即刻(T4)的MAP、HR和BIS,记录停药后苏醒时间、苏醒时BIS和PONV发生率.结果 P组苏醒时间明显短于S组(P<0.05),苏醒时BIS明显低于S组(P<0.05).P组分别有3例和2例发生术后恶心和呕吐,S组分别有6例和4例(P<0.05).结论 在梗阻性黄疽患者丙泊酚TCI麻醉较七氟醚吸入麻醉PONV发生率较低,清醒较迅速.     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

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.