不同全麻诱导药对高血压病人围诱导期血浆R-A-A-S系统的影响

在全身动脉血压的调节中,肾素-血管紧张素-醛固酮系统（Renin-angiotensin-aldosterone system,R-A-A-S）具有非常关键性的作用,围手术期对血浆肾素活性（Plasmarenin activity,PRA）、血管紧张素 Ⅱ（angiotensin Ⅱ,A Ⅱ）和醛固酮（aldosterone,Ald）系统的研究较多[1,2],本研究旨在观察不同全麻诱导药对原发性高血压病人围诱导期血     

硬膜外阻滞复合异氟醚降压对动脉导管结扎术病人肾素-血管紧张素-醛固酮系统的影响

观察比较胸段硬膜外阻滞复合异氟醚麻醉与硝普钠(SNP)+异氟醚麻醉在动脉导管未闻(PDA)结扎术中控制性降压的效果和对血浆肾素活性(PRA)、血管紧张素Ⅱ(AⅡ)、醛固酮(ALD)的影响。     

地氟醚对手术病人肾素—血管紧张素—醛固酮系统及皮质醇的影响

目的 观察地氟醚在手术中对肾素-血管紧张素-醛固酮系统（RAAS）及皮质醇的影响。方法 选择30例择期在全麻下实施上腹部手术病人，随机分为地氟醚组和安氟醚组，每组15例。术中分五个时点采集静脉血，以放免法测定血浆肾素活性（PRA）、血管紧张素Ⅱ（AⅡ）、醛固酮（Al）及皮质醇（Cor）。结果 地氟醚组在切皮时即出现PRA、AⅡ、Al的升高，尤以Al显著，术中继续升高。两组Cor术中均升高，但无明显组间差异。地氟醚组中血压及心率增加明显。结论 地氟醚可早期激活RAAS，并有交感兴奋作用；但不能抑制手术刺激引起的Cor升高。     

乙型肝炎肝硬化患者血钠水平与肾血流量的关系的研究

将90例乙型肝炎肝硬化腹水患者分为低血钠和正常血钠两组,对两组患者的肾血流量、肾素活性(PRA)、血管紧张素Ⅱ(AⅡ)、醛固酮(ALD)及肾功能损害情况作对比研究,以探讨乙型肝炎肝硬化患者血钠水平与肾血流量及肾功能损害的关系,现报道如下.     

监测肾素-血管紧张素Ⅱ-醛固酮变化评估咪唑安定-芬太尼-阿曲库铵全恁静脉麻醉下的机体应激反应

目的：通过监测肾素-血管紧张素-醛固酮浓度，评估机体在咪唑安定-芬太尼-阿曲库铵静胍复合麻醉下对伤害性刺激的应激反应。方法：选择40例上腹部和胸部手术病人，随机分为咪唑安定组和异氟醚组。在麻醉前、气管插管后1min、手术探查时及病电切除抽取中心静脉血。用放免法测定血浆肾素活性(PRA)，血管紧张素Ⅱ(AⅡ)和醛固酮(ALD)浓度，同时记录各时点的血流动力学变化。结果：咪唑安定组和异氟醚组各时点的肾素活性、血管紧张素Ⅱ和醛固酮水平均无显著性差异。血流动力学变化也无显著性差异。结论：机体在咪唑安定、芬太尼、阿曲库铵静脉复合麻醉下的应激反应与异氟醚吸入麻醉者相似，能较好抑制伤害性刺激引起的应激反应。     

环孢素A对大鼠慢性肾毒性模型肾素-血管紧张素系统的影响

目的　探讨环孢素A (CsA)慢性肾毒性的发生机理。方法　采用放射免疫分析的方法 ,观察进低盐饮食的大鼠在灌服CsA 30mg·kg- 1 ·d- 1 2 8d后血浆肾素活性 (PRA)、血管紧张素Ⅱ(AngⅡ )、醛固酮水平的变化 ,以及复方丹参注射液、贝那普利对上述改变的防护作用。结果　CsA可引起大鼠血浆PRA、AngⅡ水平明显升高 ;丹参对这些改变影响不明显 ,而贝那普利对大鼠PRA、AngⅡ水平的升高有明显的抑制作用。血浆醛固酮水平 ,各组比较 ,只有给予贝那普利者明显下降 ,其余各组之间血浆醛固酮水平的差异无显著性 (P >0 .0 5)。结论　CsA的慢性肾毒性损伤可能与肾素 血管紧张素系统 (RAS)的激活 ,尤其是与AngⅡ的增加有关 ;CsA不引起血浆醛固酮水平的升高     

硬膜外麻醉下妇科腹腔镜手术血浆肾素—血管紧张素系统和β微球蛋白含量的变化

目的观察硬膜外麻醉下,妇科腹腔镜手术患者在低CO2气腹压和15.头低脚高体位时肾素-血管紧张素系统(RAAS)和肾小球滤过率(GFR)的变化。方法监测20例患者气腹前、腹内压达1.33～1.59kPa后10、30、60分钟及解除气腹后10分钟五个时点血浆肾素(PRA)、血管紧张素Ⅱ(AⅡ)、醛固酮(ALD))和β     

5/6肾切除大鼠肾组织肾素-血管紧张素-醛固酮系统的昼夜节律

目的：研究慢性肾衰竭大鼠循环及肾局部肾素-血管紧张素-醛固酮（RAAS）的近日节律。方法：60只Wistar大鼠建立5/6肾衰竭大鼠模型,随机分为两组：肾衰组（A组,30只）,假手术组（B组,30只）。大鼠在恒温（22±2）℃,12：12h明（L）：暗（D）交替的环境中饲养12周。早上7：00开灯,记为ZT0时,依次类推,晚上19：00时关灯,记为ZT12时。在11周时留尿测24h尿蛋白定量。12周时分别留取血及肾标本。放免法检测血及肾脏肾素活性、血管紧张素Ⅱ（AngⅡ）及醛固酮（Ald）浓度。结果：与假手术组比较,肾衰组血肌酐水平及24h尿蛋白定量明显升高（P〈0.001）。无论是A组还是B组,肾组织肾素活性（KRA）、AngⅡ及Ald的近日节律与血浆中肾素活性（PRA）、AngⅡ及Ald节律不一致。如A、B组KPA的谷、峰值时间与PRA相反;血浆AngⅡ峰值时间A组在ZT20,B组在ZT16时,A、B组肾脏中AngⅡ峰值时间则在ZT4时。B组的血浆及肾RAAS各组分的近日节律与A组差异也有统计学意义。结论：大鼠肾局部RAAS节律与血浆中RAAS节律不同,慢性肾衰竭组RAAS节律与假手术组比较也发生改变。     

卡托普利对急性胰腺炎大鼠肾素血管紧张素Ⅱ水平的影响

目的 观察急性胰腺炎大鼠血浆肾素、血管紧张素Ⅱ水平变化以及卡托普利的干预效应。方法 63只SD大鼠分对照组、急性胰腺炎组、卡托普利干预组三组,进行不同处理。急性胰腺炎组用十二指肠闭襻法制作急件胰腺炎模型,干预组在制模后立即腹腔注射卡托普利（5 mg/kg）,在病程不同时点测定血浆淀粉酶（AMY）、血浆肾素活性（PRA）、血管紧张素Ⅱ（Ang Ⅱ）水平,并观察胰腺组织病理学改变。结果（1）急性胰腺炎组随着病变的进展,胰腺炎病理由水肿向出血坏死发展,病程10h内,PRA、Ang Ⅱ水平升高,胰腺炎病理呈水肿性改变;10h后,Ang　Ⅱ继续升;苟,PRA却升高不显著,但仍保持高水平,病程24h胰腺炎病理呈出血坏死性改变,胰腺组织病理学评分的会高于10h（P<0.05）。（2）卡托普利干预组随着胰腺炎病变进展,血浆PRA、Ang Ⅱ水平低于急性胰腺炎组,胰腺组织病理学评分低于急性胰腺炎组（P<0.05）。结论 早期运用卡托普利可降低血浆肾素血管紧张素Ⅱ水平,对大鼠急性胰腺炎病变有保护作用。     

颈髓损伤患者低渗血症的原因及治疗

目的：探讨急性颈髓损伤后低渗血症的相关因素及治疗方法.方法：1998年10月～2002年2月共收治114例急性颈髓损伤患者,其中完全性颈髓损伤患者42例（A组）;不完全性颈髓损伤72例（B组）;同期收治的不伴颈髓损伤的其它损伤患者41例（C组）.测定各组患者的血浆渗透压、Na^＋、K^＋、Cl^-、Ca^2＋、二氧化碳结合力（CO2CP）、血糖（Glu）、血尿素氮（Bun）、血浆蛋白质总量（TP）、白蛋白（ALB）及球蛋白（GLB）含量.对42例完全性颈髓损伤患者中35例严重低钠血症患者（血钠=120～125mmol/L）20例每天采用3%氯化钠盐水400ml静脉点滴（D组）,15例每天采用3%氯化钠盐水400ml加血浆200ml静脉点滴（E组）进行1周治疗.结果：A、B、C三组间血浆渗透压、Na^＋、Cl^-、TP及ALB、GLB含量存在显著性差异（P＜0.05）.D、E组间治疗效果存在显著性差异（P＜0.05）,E组优于D组.结论：急性颈髓损伤易并发低渗血症,其发生率与损伤的程度、低钠及低蛋白有关.同时补充盐和血浆治疗效果较好.     

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.     

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.     

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.