安氟醚和异氟醚对肝脏缺血/再灌注损害的影响

目的 研究安氟醚和异氟醚预处理对肝脏缺血／再灌注损害的影响。方法 １８只家兔随机分３组,对照组阻断肝劝脉和门静脉血流形成肝缺血４５ｍｉｎ,开放再灌注１２０ｍｉｎ;安氟醚和异氟醚预处理组,于缺血再灌注前分别吸入１．６８％安氟醚和１．１５％异氟醚２０ｍｉｎ和药物清除１０ｍｉｎ。结果 缺血前,三组血清谷丙转氨酶（ＡＬＴ）,谷草转氨酶（ＡＳＴ）、乳酸脱氢酶（ＬＤＨ）、碱性磷酸酶（ＡＬＰ）和谷氨酰酶（ＧＣＴ     

大鼠脊髓损伤后兴奋性氨基酸的变化及其对血流量的影响

采用Ａｌｌｅｎ＇ｓ打击法复制大鼠脊髓损伤（ＳＣＩ）模型，氨基酸微量检测技术和氢清除法分别测定伤段脊髓组织２４ｈ内兴奋性氨基酸（ＥＡＡ）即谷氨酸（Ｇｌｕ）、天冬氨酸（Ａｓｐ）含量和脊髓灰质血流量（ＳＣＢＦ）的变化，并观察脊髓蛛网膜下腔注射ＥＡＡ受体激动剂Ｎ－甲基－Ｄ－天冬氨酸（ＮＭＤＡ）对ＳＣＢＦ的影响，探讨ＥＡＡ在ＳＣＩ中的作用。结果发现：ＳＣＢＦ在伤后１０ｍｉｎ即有明显下降，２ｈ较１ｈ略有回升，４～８ｈ又进一步下降，第二次下降与第一次下降相差显著。伤后脊髓蛛网膜下腔注射ＮＭＤＡ明显加剧ＳＣＩ后脊髓缺血。Ｇｌｕ、Ａｓｐ伤后１０ｍｉｎ均明显升高，１～２４ｈＡｓｐ较对照组明显降低，８ｈ较２ｈ略有回升；Ｇｌｕ在伤后１０ｍｉｎ有所下降，但仍高于对照组，４ｈ、８ｈ较２ｈ略增加。ＥＡＡ变化与ＳＣＢＦ呈显著负相关。结果提示ＳＣＩ后ＥＡＡ的过度释放是ＳＣＩ后继发损伤的重要因素。     

蛋白酶抑制剂对大鼠肝缺血再灌注和原位肝移植后肝功能的保护作用

目的 探讨中性粒细胞及蛋白酶抑制剂在大鼠肝脏缺血再灌注损伤中的作用。方法 建立大鼠热缺血再灌注及原位肝移植模型。检测血清谷丙转氨酶（ＡＬＴ）、乳酸脱氢酶（ＬＤＨ）、肝脏髓过氧化物酶（ＭＰＯ）含量,观察肝脏病理组织学改变,定量计数浸润的中性粒细胞等,热缺血组于缺血前用药,缺血４５ｍｉｎ后再灌注４ｈ取样,移植组于受体术前１ｈ用药,移植４ｈ后取样。结果 对照组ＡＬＴ,ＬＤＨ,ＭＰＯ均较实验组显著升高（Ｐ〈０．０１）。组织学观察肝组织损害较重,中性粒细胞浸润明显,与实验组相比有显著差异（Ｐ〈０．０１）。结论 肝脏冷、热缺血再灌注损伤时中性粒细胞参与并起了重要的作用。而应用蛋白酶掏剂抑肽酶（ＡＰ）可以减轻缺血再灌注损伤的程度。并对肝脏功能有保护作用。     

体外循环下心肌缺血再灌注后血清过氧化脂质及前列腺素的变化

观察１０例体外循环下心内直视手术得血清过氧化脂质及前列环素的变化。结果表明，体外循环开始后血清脂质过氧化产物丙二醛（ＭＤＡ）渐进性升高，各时期ＭＤＡ均显著高于其术前（Ｔ０）值，尤其再灌注后ＭＤＡ增加迅速，于再灌注后３０ｍｉｎ（Ｔ４）显著高于心肌缺血３０ｍｉｎ（Ｔ２）时值；而体外循环开始后血清前列环素急剧增加，于Ｔ２时达高峰。再灌注后前列环素值逐渐下降，Ｔ４时前列环素值显著低于Ｔ２时的值（Ｐ〈０．０     

前列腺素E1及硝酸甘油在离体脑保护中应用的实验研究

应用兔离体肺再灌注模型研究前列腺素Ｅ１（ＰＧＥ１）及硝酸甘油ＮＴＧ）在离体肺保护中的作用。１８只随机平均分为两组，对照组以ＬＰＤ液进行肺灌洗及保存，用药组以ＰＧＥ１１００μｇ．Ｌ＾－１及ＮＴＧ１０ｍｇ．Ｌ＾－１加入ＬＰＤ液中进行肺灌洗及保存。每组再分为三小组分别保存２、４、８小时后进行再灌注，测定再灌注后肺血管阻力（ＰＶＲ）、肺通所阻力ＬＲ，肺含水量及动脉发压以了解肺保护效果。结果示；用药组再灌注     

前列腺素E1及硝酸甘油在离体肺保护中应用的实验研究

应用兔离体肺再灌注模型研究前列腺素Ｅ１（ＰＧＥ１）及硝酸甘油（ＮＴＧ）在离体肺保护中的作用。１８只兔随机平均分为两组，对照组以ＬＰＤ液进行肺灌洗及保存，用药组以ＰＧＥ１１００μｇＬ－１及ＮＴＧ１０ｍｇＬ－１加入ＬＰＤ液中进行肺灌洗及保存。每组再分为三小组（各含６个肺）分别保存２、４、８小时后进行再灌注，测定再灌注后肺血管阻力（ＰＶＲ），肺通气阻力（ＬＲ），肺含水量（ＬＷ）及动脉血氧分压（ＰａＯ２）以了解肺保护效果。结果示：用药组再灌注后ＰＶＲ明显低于对照组（Ｐ＜０．０５）。ＬＲ、ＬＷ及ＰａＯ２两组无差别。说明ＰＧＥ１及ＮＴＧ在保护肺血管内皮细胞及降低再灌注后肺血管阻力方面明显优于对照组。ＰＧＥ１及ＮＴＧ作用机理可能是通过肺动脉扩张改善肺早期灌洗及抵制中性粒细胞，血小板在肺内聚集而减轻肺再灌注损伤     

缺血再灌注对大鼠肺细胞间粘附分子-1表达的影响

目的 观察缺血再灌注（Ｉ／Ｒ）对肺组织细胞间粘附分子－１（ＩＣＡＭ－１）表达的影响，分析ＩＣＡＭ－１表达与肺内中性粒细胞浸润的关系。方法 Ｗｉｓｔａｒ大鼠单肺原位热缺血再灌注损伤模型分７组，左肺缺血９０ｍｉｎ，再灌注时间分别为０、１、２、４、８、１６、２４ｈ。逆转录－聚合酶链式反应（ＲＴ－ＰＣＲ）法及Ｗｅｓｔｅｒｎ ｂｌｏｔ法检测肺组织ＩＣＡＭ－１ｍＲＮＡ及蛋白表达，测定各组肺组织髓过氧化物酶活性     

大鼠肝脏缺血再灌注及低温保存过程中氧自由基变化的实 …

目的 观察大鼠肝脏缺血再灌注及低温保存过程中氧自由基的变化。方法 建立大鼠肝脏假手术、热缺血再灌注和原位肝移植模型,分别测定再灌注１ｈ和移植术后２ｈ下腔静脉血中超氧化物歧化酶（ＳＯＤ）、乳酸脱氢酶（ＬＤＨ）和血清中指质过氧化物（ＬＰＯ）的变化,并进行组织学观察。结果 术前３０ｍｉｎ静脉注射别嘌呤或灌洗液及保存液中加别嘌呤的实验组大鼠,其全血中ＳＯＤ的活力高于条件相同、但不给予别嘌醇的对照组,ＬＰＯ     

麻醉和手术对肾小球和肾小管功能的影响

目的 了解麻醉与手术对肾小球和肾小管功能的影响。方法 病人分为４组；１、全身麻醉＋较大手术组（Ｇ＋Ｂ）；２、全身麻醉＋较小手术组（Ｇ＋Ｓ）；３、硬膜外阻滞＋较大手术组（Ｅ＋Ｂ）；４、硬膜外阻滞＋较小手术组（Ｅ＋Ｓ）。每组１０例。检测术前、术中１ｈ和术后２４ｈ尿中β２－微球蛋白（β２－ＭＧ）、白蛋白Ａｌｂ）和免疫球蛋白Ｇ（ＩｇＧ）浓度。结果 在不同麻醉方法下行较小手术时，术中及术后尿中β２－ＭＧ、Ａ     

磷脂酶A2抑制剂对肠缺血再灌注致多器官功能损伤的保护作用

采用大鼠肠系膜上动脉阻断模型，初步探讨磷脂酶Ａ２（ＰＬＡ２）抑制剂阿的平对肠缺血再灌注（Ｉ／４）致多器官损伤的保护作用。结果发现：肠Ｉ／Ｒ诱发的肠源性内毒素血症、菌血症与肠ＰＬＡ２活性升高密切相关；预防性静脉给予阿的平１０ｍｇ／ｋｇ，肠ＰＬＡ２活性及其产生的脂质介质ＴＸＡ２、ＰＧＩ２水平下降，细菌、内毒素易位减轻，同时肝、肺、肾等脏器功能指标明显改善，动物致伤２４ｈ存活率提高２５％。     

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.