不同Fontan手术的动物实验对比研究

目的 通过动物实验模似右房－右室连接术、全腔静脉肺动脉连接术及右房－肺动脉吻合术,对比研究３种术式的血流动力学效果及能量损耗情况。方法 选１５只成年杂种犬,随机分成右房－右室连接、全腔静脉肺动脉连接及右房－肺动脉吻合３种,每组５只。右房－右室连接组分别利用５０％及２５％的右室容积参与Ｆｏｎｔａｎ循环。比较三间组的血流动力学参数及能量损耗。结果 与右房－肺动脉连接组相比,无论是５０％还是２５％的右室     

改良全腔静脉-肺动脉连接术治疗功能性单心室

目的 为了进一步改善全腔静脉－肺动脉连接手术的效果,探讨其经典手术方式的改良方法。方法 对１３例功能性单心室施行了改良全腔静脉－肺动脉妆手术 上腔静脉远心民右肺动脉上缘作端侧吻合,吻合口尽量偏左,近心端与右肺动脉下缘吻合,吻合口尽量偏右。其中５便在心脏不停跳下用Ｇｏｒｅ－Ｔｅｘ心外管道连接下腔静脉与右肺动脉下缘,８例采用心房内隧道。结果 术后早期死亡１例（７．７％）,１２例（９２．３％）存活者术后     

全腔肺动脉连接术在复杂先心病手术中的应用

１９９２～１９９３年为９例复杂先心病病人行全腔肺动脉连接术。均在心脏跳动下作双向上腔静脉—肺动脉吻合；１例作上腔静脉近心端与右肺动脉侧侧吻合，８例作右房上腔静脉开口与主肺动脉端端吻合。心房内管道置入５例，复合性内通道２例，心房内分隔２例。平均主动脉阻断时间３０分钟，平均心肌温度１０℃，全部心脏自动复跳，病人均痊愈出院。结论：对于复杂的先心病，全腔肺动脉吻合术的姑息性效果较其它改良Ｆｏｎｔａｎ术式要好，但远期效果有待进一步观察和评估     

非体外循环下改良全腔静脉-肺动脉连接术

目的：探讨非体外循环下行改良全腔静脉－肺动脉连接手术治疗功能性单心室技术。方法：3例功能性单心室病儿在非体外循环下施行了改良全腔静脉－肺动脉连接手术。术中先作上、下腔静脉插管并与右房插管连接，静脉血分流入右房，然后置右肺动脉侧壁钳，上腔静脉远心端与右肺动脉上缘行端侧吻合，吻合口尽量偏左；下腔静脉通过心外管道与右肺动脉下缘连接，吻合口尽量偏右。最后缝扎肺动脉口。结果：术后无早、晚期死亡，仅1例发生低心输出量综合征及胸腔渗出。动脉血氧饱和度0．94－0．97。术后随访1－3个月，心功能I级2例，Ⅱ级1例。结论：非体外循环下行改良全腔静脉－肺动脉连接术，是治疗功能性单心室的有效技术，可取得良好的手术效果。     

不同全腔静脉肺动脉连接术式对腔静脉回流、肺血分布以及能量消耗的影响

目的：探讨不同的全腔静脉肺动脉连接（TCPC）术式对腔静脉回流、肺血分布以及能量消耗的影响。方法：建立接近临床TCPC术的实验动脉模型，采用3种不同的TCPC术式：（1）上、下腔静脉与右肺动脉吻合口相对；（2）下腔静脉与右肺动脉吻合口偏向上腔静脉与右肺动脉吻合口的右侧；（3）下腔静脉与主肺动脉吻合口位于上腔静脉与右肺动脉吻合口左侧。术后测量上、下腔静脉血流量，左、右肺动脉血流量，进行肺血管造影了解肺血分布，通过伯努力公式计算能量消耗。结果：3种TCPC术后上、下腔静脉血流量的分布发生了变化，上腔静脉／下腔静脉血流量比值在1．0左右；通过测定左、右肺动脉流量以及造影发现，术式（3）下腔静脉血基本进入左肺；术式（2）下腔静脉血较多进入右肺；右肺动脉／左肺动脉血流量与术前比差异有显著性（P＜0．01）；术式（3）能量消耗较术式（1）显著降低（P＜0．01）。结论：TCPC术后，体静脉回流情况发生了变化；不同TCPC术后，腔静脉位置决定了静脉回流的方向；右肺动脉／左肺动脉血流量比值较术前差异有显著性（P＜0．01）；TCPC术后，上、下腔静脉吻合口相对时能量消耗最大，完全错开时能量消耗小。     

全腔静脉肺动脉连接术的疗效与术式评价

目的 探讨全腔静脉肺动脉连接术（TCPC）的外科治疗效果并对相关术式进行评价。方法 1998年2月至2006年6月，对51例复杂先天性心脏病病儿采用TCPC予以纠治，15例采用心内隧道术式、29例采用心外管道术式、7例采用主肺动脉与下腔静脉直接吻合术式。结果 手术死亡4例（7.8％）。此外，术后低心排出量综合征6例（12．8％）、心律失常14例（29．8％）。80．1％术后24h内撤离呼吸机。术后48．9％留置胸引流管超过7d。随访1个月至8年，9例（19．1％）术后6个月后仍需长期或间断服用强心、利尿剂，7例（14．7％）有房性心律失常。结论 全腔静脉肺动脉连接术可取得满意的外科治疗效果。应用主肺动脉下腔静脉直接吻合术式，在部分病例中可望成为理想术式。     

心外管道全腔静脉肺动脉吻合术的临床应用进展

自1971年首次报道Fontan手术应用临床以来，该术式经过不断改良，已经逐渐成为许多不能进行双心室矫治的复杂性先天性心脏病(先心病)的主要治疗方法。全腔静脉肺动脉吻合术(TCPC)因具有良好的血流动力学特征和较好的临床治疗效果、较少的术后并发症，成为该类术式中应用比较广泛的手术方式，并且也有了较大发展。心外管道全腔静脉肺动脉吻合术(ECTCPC)由于其良好的治疗结果及相对简单的手术操作，被认为是目前最好的右心旁路手术。现就其应用进展综述如下。     

心外管道全腔静脉肺动脉连接术

目的 报告心管道全腔静脉肺动脉连接术（TECPC）应用经验。方法 横断上腔静脉与右肺动脉端侧吻合,切断下腔静脉前壁,保留原位吻合口,将下腔静脉通过人工血管与主肺动脉吻合,共治疗9例复杂性先天性心脏病,其中1例单心室改良Fontan术后4年频发室上性心动过速而改行TECPC。结果 全组手术后均生存。3例术后出现胸腔积液、乳糜胸并发症、均治愈。血流动力学指标满意,术后随访心功能Ⅰ-Ⅱ级,无心律紊乱发生。结论 TECPC手术操作简单,并发症少,适应证广泛,优于改良Fontan手术和传统的全腔静脉肺动脉连接术。     

心外管道全腔静脉-肺动脉连接术在复杂先天性心脏病外科治疗中的应用

目的总结心外管道全腔静脉-肺动脉连接术治疗复杂先天性心脏病的应用经验及其治疗效果。方法回顾性分析2006年9月至2012年12月间广州军区广州总医院心脏外科中心52例行心外管道全腔静脉-肺动脉连接术患者的临床资料。12例行一期心外管道全腔静脉-肺动脉连接术,40例为双向Glenn手术后行二期心外管道全腔静脉-肺动脉连接术。分析所有患者的临床资料,并比较两种手术方式患者的死亡率、并发症发生率、住院时间、住重症监护室（ICU）时间、机械辅助通气时间、动脉血氧饱和度的改善情况等。结果围术期死亡2例,死亡率3．8％。其中1例术后因严重低心排血量综合征死亡,1例术后因多器官功能衰竭死亡;50例治愈出院。二期心外管道全腔静脉．肺动脉连接术患者（40例肌械辅助通气时间、住ICU时间、住院时间明显短于一期心外管道全腔静脉-肺动脉连接术患者（12例）,但两种手术方式患者术后并发症发生率及术后动脉血氧饱和度（二期手术与一期手术比较：93％±3％vs．94％±3％）、死亡率（二期手术与一期手术比较：2．5％vs．8．3％）差异均无统计学意义（P〉0．05）。随访45例（90％）,随访时间6～52个月,随访期间无死亡。术后3个月,存活患者心功能均为Ⅰ～Ⅱ级,心脏彩色超声心动图显示：腔静脉肺动脉吻合口血流通畅。结论心外管道全腔静脉．肺动脉连接术血流动力学更符合生理血流动力学特点,手术操作简捷,是不能进行双心室治疗时的有效手术术式;分期心外管道全腔静脉-肺动脉连接术较一期心外管道全腔静脉-肺动脉连接术手术适应证广泛,术后恢复较好,更易推广。     

上腔静脉肺动脉双向分流合并双心室的实验研究

我们通过动物实验 ,研究上腔静脉 肺动脉双向分流 (ＢＣＰＳ)合并右心室来源的搏动性肺血流的血流动力学特点 ,为临床应用提供实验资料 ,现将结果报道如下。一、材料和方法实验犬全麻气管插管接呼吸机 ,正中开胸 ,作为分流管道的同种异体动脉 ,一端同上腔静脉 (ｓｕｐｅｒｉｏｒｖｅｎｏｃａｖａ ,ＳＶＣ)、另一端右肺动脉行端侧吻合 ,结扎ＳＶＣ近右心房处 ,建立合并右心室搏动性血流的ＢＣＰＳ模型 (ＢＣＰＳ组 ) ;再结扎右肺动脉近心端 ,则建立上腔静脉 肺动脉单向分流模型 (ＳＣＰＳ组 ) ;对照组 (Ｃ组 )仅行开胸操作。 3组实验犬均为…     

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.