体外膜肺氧合技术在心脏死亡器官捐献中的应用

由于心脏死亡器官捐献(DCD)供者经历长时间热缺血损伤,术后原发性移植物无功能(PNF)和移植物功能丧失发生率较高,曾一度摒弃不用.20世纪90年代,随着等待移植的患者数量迅速增加,等待移植患者的死亡率不断攀升,DCD再度作为扩大标准的供者(ECD)被用于临床.为了减轻热缺血损伤,部分移植中心利用体外膜肺氧合(ECMO)技术对来自DCD的器官进行保护,认为ECMO对保障DCD的移植受者安全有着积极的作用.本文就ECMO在DCD中的应用进行综述.     

心死亡器官捐献实施过程中使用体外膜肺氧合技术的相关技术问题

由于器官短缺问题的日趋严重,心死亡/循环死亡(donation after cardiac/circulatory death,DCD)器官捐献日益增多.但是,DCD器官捐献面临的一项重要问题是长时间的热缺血对器官的损伤.经历较长时间的热缺血损伤后器官的可用性明显降低,术后移植物发生器官原发性无功能(primary nonfunction PNF)和移植物功能恢复延迟(delayed graft function,DGF)的几率增加,也影响移植物存活率.体外膜肺氧合技术(extracorporeal membrane oxygenation,ECMO)应用于DCD器官捐献,氧合自体血再灌注对器官起到了保护作用,也明显缩短了热缺血时间,在提高器官可用性及改善术后移植物功能方面效果明显.本文就DCD实施过程中使用ECMO支持的相关技术问题及争议进行综述.     

心脏死亡器官捐献获取流程探讨

目的总结并进一步探讨心脏死亡器官捐献(DCD)获取流程的初步经验。方法回顾性分析2009年7月至2012年1月期间广州军区总医院28例DCD者的临床资料、供体入选标准及器官获取流程。结果 28例DCD供体均成功实施了器官捐献,其中MaastrichtⅢ类3例(10.7%),MaastrichtⅣ类1例(3.6%),脑-心双死亡捐献(DBCD)供体24例(85.7%)。3例MaastrichtⅢ类供体实施了标准DCD器官获取流程(简称DCD流程),1例MaastrichtⅣ类供体采用DBCD器官获取流程(简称DBCD流程)非体外膜肺氧合(ECMO)模式,24例DBCD采用了DBCD流程ECMO模式。供体器官热缺血时间:DBCD为0 min,MaastrichtⅣ类为18 min,MaastrichtⅢ类平均25 min(22～28 min)。本组共获取了28个肝脏、40个肾脏、2个心脏,分别成功用于肝移植、肾移植和心脏移植。结论我国DCD器官获取可分为DCD流程和DBCD流程,后者又分为ECMO模式和非ECMO模式。ECMO模式可避免器官热缺血损伤且没有伦理学争议,对我国公民DCD器官有着十分重要的作用。     

心脏死亡供肾评估和保存的现状及进展

由于心脏死亡捐献(DCD)器官较脑死亡捐献(DBD)器官的热缺血时间更长,组织缺氧、缺血再灌注损伤也较严重,这就增加了不可逆的移植物原发性无功能(PNF)和移植肾功能恢复延迟(DGF)的发生.因此,对DCD器官进行科学的评估和保存,选择质量较好的供肾,缩短供肾的热缺血时间,从而减轻组织缺氧和炎症反应等不利因素,是减少PNF和DGF,增加移植物活力及受者存活率的有效手段.现就此作如下综述.     

中国心脏死亡器官捐献工作发展及影响因素:单中心经验

目的总结中国心脏死亡器官捐献(DCD)发展概况、影响潜在DCD供者捐献因素及体外膜肺氧合(ECMO)技术应用的单中心经验。方法回顾性分析2010年1月至2015年12月广州军区总医院器官获取组织(OPO)服务范围内所有DCD供者资料。总结我院DCD例数、年均增长率、每百万人口器官捐献率、DCD来源供肝丢弃情况、中国Ⅰ、Ⅱ、Ⅲ类捐献比例、我院OPO服务范围内潜在DCD供者捐献影响因素及ECMO在DCD中的应用情况。同时查阅同一时期中国及广东省DCD数据。我院与全国中国Ⅰ类供者比例、我院和广东省DCD例数年均增长率比较分别采用卡方检验和Man-Whitney U检验。P0.05为差异有统计学意义。结果2010年1月至2015年12月,我院共实现241例DCD,中国Ⅰ、Ⅱ、Ⅲ类捐献比例分别为29.9%(72/241)、26.6%(64/241)、43.5%(105/241)。我院中国Ⅰ类捐献比例(29.9%)高于全国水平(13%)(χ2=55.381,P0.05)。241例DCD共获取供肝234例,因供肝因素放弃移植26例,丢弃率为11.1%(26/234),影响供肝丢弃主要因素为冷/热缺血时间过长、供肝肝硬化、灌注不良、肝功能异常和挫裂伤。期间,我院和广东省DCD例数年均增长率分别为67.78%和104.50%(U=11.0,P0.05),差异无统计学意义;我院和广东省每百万人口(PMP)器官捐献率分别从0.407、0.144 PMP升高至3.948、4.145 PMP。同期我院OPO服务范围内医院上报潜在DCD供者778例,捐献转化率为31.0%(241/778)。影响潜在DCD供者捐献的因素主要包括家属及社会因素、供者自身病情及医患关系。2010年1月至2015年12月,我院共完成145例ECMO辅助下DCD器官获取,其中中国Ⅰ、Ⅱ、Ⅲ类捐献供器官中应用率分别为58.3%(42/72)、62.5%(40/64)和60.0%(63/105)。结论提高公众对器官捐献的关注度和接受度,合理应用器官保存技术,将有助于推动DCD肝移植发展。     

体外膜肺氧合技术在心脏死亡或脑死亡器官捐赠中应用的进展

由于对供者器官的需求量日益增多,而标准脑死亡器官捐赠(DBD)的来源并未增加,供移植器官短缺的问题日趋严重,因而扩大标准的供者(ECD)不断增多.ECD的重要来源包括难以维持循环功能稳定等基本条件的部分DBD,以及心脏死亡器官捐赠(DCD).作为ECD,无疑会增加热缺血时间,使得器官移植后的存活能力降低,发生器官原发性无功能(PNF)的几率较高.将体外膜肺氧合(ECMO)技术应用于DCD和DBD中,能够有效缩短器官的热缺血时间,对已受热缺血损伤的器官可通过相应的体外循环支持措施,使其功能恢复.目前,ECMO技术在DCD和DBD中逐渐应用,有效地提高了ECD的使用率.     

体外膜肺氧合在心脏死亡器官捐献供体肝移植中的应用进展

供肝短缺已经成为制约肝移植发展的重要因素,心脏死亡器官捐献(DCD)供体是扩大供体池的一个重要来源。应用体外膜肺氧合(ECMO)技术可提高DCD供肝的质量,增加器官捐献供体池,改善肝移植受体的预后。本文综述了ECMO对DCD供体器官支持的基本原理和操作技术、ECMO用于DCD供体肝移植的研究进展及存在的问题,提示ECMO在我国DCD供体肝移植中具备较大的发展潜力和应用前景。     

体外膜肺氧合用于尸体供器官保护的技术操作规范(2019版)

为了进一步规范临床将体外膜肺氧合(ECMO)用于尸体供器官保护的技术操作,中华医学会器官移植学分会组织器官移植学专家从ECMO应用基本原则,ECMO在脑死亡器官捐献(DBD)、心脏死亡器官捐献(DCD)、脑-心双死亡器官捐献(DBCD)中的应用规范等方面,制订各类供体应用ECMO的技术规范。     

DCD供肝术前评估应注意的问题

<正>心脏死亡器官捐献(Donation after cardiacdeath,DCD)已成为我国器官来源的主要途径。除了器官获取和运输过程中通常关注的热缺血、冷缺血时间等因素影响外,DCD捐献者还受到原发病及救治过程中多种不确定因素的影响,国外甚至将DCD供肝作为边缘供肝~([1]),认为其具有较高的移植肝无功能、缺血性胆道病变发生率。因此如何对DCD供肝质量进行准确评估是保证保障较好移植效果的关键     

10例心脏死亡器官捐献移植总结

目的通过分析我院实施的心脏死亡器官捐献(DCD)移植病例,探讨国内DCD器官和移植方面的问题。方法对我院2010～2011年期间参与实施的DCD器官移植的临床资料进行回顾性总结。结果本组有4例DCD者共实施了7例肾移植和3例肝移植。捐献者1属于中国DCD器官分类标准(中国标准)二类(MaastrichtⅣ类),热缺血时间40 min,经快速病理检查后放弃了肝脏和左侧肾脏,右侧肾脏进行了移植后患者出现移植肾功能延迟恢复,最终移植肾因破裂出血而被切除。捐献者2～4属于中国标准三类(MaastrichtⅢ类),热缺血时间分别为15、15、10 min,其中捐献者4在器官捐献前已经出现血压下降,需要大剂量多巴胺维持血压,供肝进行了快速病理检查,确认可以使用;捐献者2和3由于是在手术室进行可控性心跳及呼吸终止,热缺血时间均为15 min,未进行病理学检查;共实施了3例肝移植和6例肾移植,手术顺利,移植物功能恢复良好,无并发症发生,无移植患者死亡。结论通过选择符合中国标准三类的捐献者,实施可控的DCD程序,DCD器官移植可以获得满意的效果。供体器官的快速病理检查有利于器官质量的判断,减少移植手术后并发症的发生。     

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.     

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.     

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.     

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.