血管内氧合器的研制

为了探索呼吸辅助的新方法，我们采用国产聚丙烯中空纤维，自行设计、制造模具，研制出一种血管内氧合器。该氧合器是一个小的、细长的可经单侧股静脉或颈静脉切开，置入腔静脉内的装置。氧合器有效长度４０ｃｍ，膜交换面积０．０９ｍ＾２。经负压调节通过血管内氧合器的氧流量，以防止纤维破裂造成的血管内气栓的危险。一根双腔导气管使气体经同一静脉切开部位循环，气体经内芯管流经血管内氧合器尖端，然后经中空纤维束流出。目前     

两种氧合器对心肺转流炎症反应的影响

目的动态监测室间隔缺损修补术患者在心肺转流(CPB)各时段血清可溶性细胞间粘附分子(sICAM-1)、可溶性E-选择素(sE-selection)及肿瘤坏死因子α(TNF-α)的变化规律,并比较西京-90鼓泡式氧合器和希健-Ⅱ膜式氧合器对其的影响。方法选择择期行室间隔缺损修补术的患者30例,随机均分为鼓泡式氧合器组(B组)和膜式氧合器组(M组)。所有患者分别在麻醉后CPB开始前(T1)、主动脉阻断开放前(T2)、CPB结束时(T3)、术后2h(T4)、6h(T5)、24h(T6)及48h(T7)取静脉血5ml用ELISA法测定sICAM-1、sE-selection及TNF-α的浓度。结果两组患者血清中的TNF-α于T2时开始显著升高,T4时达到峰值(P<0·01)。sICAM-1于T5时开始升高,T6时达峰值。sE-selection于T4时开始升高,T5时达峰值(P<0·01)。M组大部分时点TNF-α、sICAM-1、sE-selection的浓度均低于B组。结论希健-Ⅱ膜式氧合器引起的炎症反应较轻。     

不同氧合器对体外循环心脏手术患儿中性粒细胞凋亡的影响

目的 研究小儿体外循环(cardiopulmonary bypass,CPB)中不同氧合器对中性粒细胞(PMN)凋亡的影响,为减轻体外循环伞身炎症反应提供新的思路.方法 将60例室间隔缺损患儿随机分为两组(n=30):西京-90鼓泡式氧合器组(B组)和希健-Ⅱ膜式氧合器组(M组).分别于CPB前、CPB结束时、CPB结束后4、8、24 h 5个时点采取静脉血,以伞血细胞计数仪测定PMN数量,流式细胞仪测定PMN凋亡率和PMN表面黏附分子CD11b表达变化,ELISA法测定血浆弹性蛋白酶浓度.结果 两组患者CPB结束后PMN凋亡率明显降低(P<0.05),PMN数量、CD11b表达、血浆弹性蛋白酶浓度明显升高(P<0.05),在CPB结束时及CPB结束后4、8 h PMN凋亡率M组均高于B组(P<0.05);而PMN数量、CD11b表达、血浆弹性蛋白酶水平B组均高于M组(P<0.05).CPB结束后24 h PMN数量B组高于M组(P<0.05).结论 与西京-90鼓泡氧合器相比,应用希健-Ⅱ膜式氧合器可以减轻CPB对PMN凋亡的抑制,进而减轻全身炎症反应.     

不同氧合器对体外循环心脏手术患儿中性粒细胞凋亡的影响

Objective To evaluate the effect of two kind oxygenators on polymorphonuclear neutrophil (PMN) apoptosis, and to give a method of inhibting the systemic inflammatory response syndrome(SIRS) to cardiopulmonary bypass(CPB). Methods Sixty VSD patients undergoing open heart surgery with CPB were randomly divided into two groups(n = 30): group B(bubble oxygenator), group M(membrane oxygenator). Blood samples were drawn from the central venous line before starting CPB, at the end of CPB, 4, 8 and 24 h after CPB. The PMN counts were performed by blood cell counter. PMN apoptosis and the expression of CD11b were evaluated by flow eytometry. The plasma concentration of elastase was determined by enzyme linked immunosorbent assays. Results The rates of PMN apoptosis were significantly reduced (P<0.05) and the PMN counts, the expression of CD11b and the plasma con-centration of elastase were remarkably increased after CPB(P<0.05), but at the end of CPB, 4 h and 8 h after CPB the rate of PMN apoptosis was higher in group M than that in group B. PMN counts, the expression of CDI lb and the plasma concentration of elastase were higher in group B than in group M (P<0.05). The PMN counts were higher in group B than in group M 24 h after CPB (P< 0.05). Conclusion XiJian-Ⅱ membrane oxygenator can increase PMN apoptosis and depress systemic inflammatory response better than XIJing-90 bubble oxygenator.     

不同氧合器对体外循环心脏手术患儿中性粒细胞凋亡的影响

Objective To evaluate the effect of two kind oxygenators on polymorphonuclear neutrophil (PMN) apoptosis, and to give a method of inhibting the systemic inflammatory response syndrome(SIRS) to cardiopulmonary bypass(CPB). Methods Sixty VSD patients undergoing open heart surgery with CPB were randomly divided into two groups(n = 30): group B(bubble oxygenator), group M(membrane oxygenator). Blood samples were drawn from the central venous line before starting CPB, at the end of CPB, 4, 8 and 24 h after CPB. The PMN counts were performed by blood cell counter. PMN apoptosis and the expression of CD11b were evaluated by flow eytometry. The plasma concentration of elastase was determined by enzyme linked immunosorbent assays. Results The rates of PMN apoptosis were significantly reduced (P<0.05) and the PMN counts, the expression of CD11b and the plasma con-centration of elastase were remarkably increased after CPB(P<0.05), but at the end of CPB, 4 h and 8 h after CPB the rate of PMN apoptosis was higher in group M than that in group B. PMN counts, the expression of CDI lb and the plasma concentration of elastase were higher in group B than in group M (P<0.05). The PMN counts were higher in group B than in group M 24 h after CPB (P< 0.05). Conclusion XiJian-Ⅱ membrane oxygenator can increase PMN apoptosis and depress systemic inflammatory response better than XIJing-90 bubble oxygenator.     

不同氧合器对体外循环心脏手术患儿中性粒细胞凋亡的影响

Objective To evaluate the effect of two kind oxygenators on polymorphonuclear neutrophil (PMN) apoptosis, and to give a method of inhibting the systemic inflammatory response syndrome(SIRS) to cardiopulmonary bypass(CPB). Methods Sixty VSD patients undergoing open heart surgery with CPB were randomly divided into two groups(n = 30): group B(bubble oxygenator), group M(membrane oxygenator). Blood samples were drawn from the central venous line before starting CPB, at the end of CPB, 4, 8 and 24 h after CPB. The PMN counts were performed by blood cell counter. PMN apoptosis and the expression of CD11b were evaluated by flow eytometry. The plasma concentration of elastase was determined by enzyme linked immunosorbent assays. Results The rates of PMN apoptosis were significantly reduced (P<0.05) and the PMN counts, the expression of CD11b and the plasma con-centration of elastase were remarkably increased after CPB(P<0.05), but at the end of CPB, 4 h and 8 h after CPB the rate of PMN apoptosis was higher in group M than that in group B. PMN counts, the expression of CDI lb and the plasma concentration of elastase were higher in group B than in group M (P<0.05). The PMN counts were higher in group B than in group M 24 h after CPB (P< 0.05). Conclusion XiJian-Ⅱ membrane oxygenator can increase PMN apoptosis and depress systemic inflammatory response better than XIJing-90 bubble oxygenator.     

不同氧合器对体外循环心脏手术患儿中性粒细胞凋亡的影响

Objective To evaluate the effect of two kind oxygenators on polymorphonuclear neutrophil (PMN) apoptosis, and to give a method of inhibting the systemic inflammatory response syndrome(SIRS) to cardiopulmonary bypass(CPB). Methods Sixty VSD patients undergoing open heart surgery with CPB were randomly divided into two groups(n = 30): group B(bubble oxygenator), group M(membrane oxygenator). Blood samples were drawn from the central venous line before starting CPB, at the end of CPB, 4, 8 and 24 h after CPB. The PMN counts were performed by blood cell counter. PMN apoptosis and the expression of CD11b were evaluated by flow eytometry. The plasma concentration of elastase was determined by enzyme linked immunosorbent assays. Results The rates of PMN apoptosis were significantly reduced (P<0.05) and the PMN counts, the expression of CD11b and the plasma con-centration of elastase were remarkably increased after CPB(P<0.05), but at the end of CPB, 4 h and 8 h after CPB the rate of PMN apoptosis was higher in group M than that in group B. PMN counts, the expression of CDI lb and the plasma concentration of elastase were higher in group B than in group M (P<0.05). The PMN counts were higher in group B than in group M 24 h after CPB (P< 0.05). Conclusion XiJian-Ⅱ membrane oxygenator can increase PMN apoptosis and depress systemic inflammatory response better than XIJing-90 bubble oxygenator.     

Clinical evaluation of the microporous hollow fiber oxygenator

This report concerns a clinical evaluation for a newly devised hollow fiber oxygenator, Capiox II. It functions on a one-pump system, and is simple to set up and operate. This equipment was used for 118 patients undergoing cardiac surgery at Tokyo University Hospital from February 1982 through February 1983. The gas transfer capacity proved to be satisfactory. The employment of an air-oxygen blender prevented overoxygenation, and reasonable levels of PaO₂ and PaCO₂ were demonstrated with a FiO₂ 0.7, ratio 0.7 at normothermia. The destruction of platelets was much less with the use of this oxygenator, as compared to findings with the BOS-10. Hemolysis by Capiox II appeared to be lower than that by BOS-10, but the difference was not statistically significant. Differences were distinct in the amount of microbubbles; strikingly, no bubble was evidenced in Capiox II by the ultrasound bubble detector, during general procedures. We conclude that Capiox II is of excellent clinical value, and should be used especially for infants as well as adult patients with possible long perfusions. The merits and demerits of this equipment are given attention.     

Water condensation from gas outlet of oxygenator

Condensation and water loss from gas output of the cardiopulmonary bypass (CPB) oxygenator has been the study object of several research. However, little is known about the propagation of the condensation formed at the level of oxygenator and how potentially it can contaminate the surrounding environment. We aimed to document the moment of formation of the ‘gas steam’ derived from the CPB oxygenator during cardiac surgery with thermography imaging. Thermographic camera is a device that creates an image using infrared radiation, similar to a common camera that forms an image using visible light. The brightest (warmest) parts of the image are customarily colored white, the intermediate temperatures reds and yellows, and the dimmest (coolest) parts black. Thermal image captures the condensation phenomenon around the oxygenator perimeter with the same color/temperature code (yellow) of gas outlet. The use of aspiration at the level of the gas outlet could also favor the elimination of the condensation, improve gas exchanges, and potentially reduce the spread of hazardous substances in the operating room.     

Intravascular Oxygenator: A New Alternative Method for Augmenting Blood Gas Transfer in Patients With Acute Respiratory Failure

A unique hollow fiber membrane oxygenator (IVOX) has been developed, which is inserted into the vena caval blood stream to transfer O2/CO2 to/from circulating blood in an intact subject without involving the natural lungs. Extensive laboratory testing has demonstrated that the device can transfer significant quantities of O2 and CO2 for up to 3 weeks without significant harmful sequelae or complications. Clinical trials are in progress under FDA supervision, in which IVOX has been utilized to date in 56 patients with ARDS. Preliminary findings indicate that risks and hazards from IVOX are nil, and evidence of benefit to the patient has been demonstrated in 86% of the patients. At this time, clinical utilization of IVOX is in the experimental, data collecting mode to determine its proper role or niche as a method for temporary augmentation of blood gas transfer in patients with advanced acute respiratory failure.     

Experimental use of a compact centrifugal pump and membrane oxygenator as a cardiopulmonary support system

Compactness and high performance are the most important requirements for a cardiopulmonary support system. The Nikkiso (HPM-15) centrifugal pump is the smallest (priming volume; 25 ml, impeller diameter; 50 mm) in clinically available centrifugal pumps. The Kuraray Menox (AL-2000) membrane oxygenator, made of double-layer polyolefin hollow fiber, has a minimum priming volume (80 ml) and a low pressure loss (65 mm Hg at 2.0 L/min of blood flow) compared with other oxygenators. The aim of this study was to evaluate the performance of the most compact cardiopulmonary support system (total priming volume: 125 ml) in animal experiments. The cardiopulmonary bypass was constructed in a canine model with the Nikkiso pump and Menox oxygenator in comparison with a conventional cardiopulmonary support system. The partial cardiopulmonary bypass was performed for 4 h to evaluate the gas exchange ability, blood trauma, serum leakage, hemodynamics, and blood coagulative parameters. The postoperative plasma free hemoglobin level of the compact cardiopulmonary system was 29.5 +/- 10.21 mg/dl (mean +/- SD), which was lower than that of the conventional cardiopulmonary system, 48.75 +/- 27.39 mg/dl (mean +/- SD). This compact cardiopulmonary system provided the advantage in terms of reduction of the priming volume and less blood damage. These results suggested the possibility of miniaturization for the cardiopulmonary bypass support system in open-heart surgery in the near future.     

Acute oxygenator occlusion in two cases of polycythemia vera: Bailout strategies

Polycytemia vera (PV) is a rare myeloproliferative neoplasm associated with microcirculatory disturbances, thrombosis and bleeding. Patients suffering from PV have a high risk of perioperative adverse events, but the literature regarding on-pump procedures in PV patients is scarce. We report two cases of acute and severe oxygenator failure during cardiopulmonary bypass and present valid exit scenarios.     

In vitro validation of the Affinity NT oxygenator arterial outlet temperatures

During cardiopulmonary bypass, the rates of cooling and rewarming and the maximum temperatures attained are implicated in patient morbidity. Thus, accurate oxygenator arterial outlet temperature measurements are needed. The purpose of this study was to determine the accuracy of the arterial outlet temperature probe on the "Affinity NT" membrane oxygenator in measuring perfusate temperatures. An in vitro circuit was used. Crystalloid solution was recirculated through an Affinity NT membrane oxygenator and, to simulate the patient, a second oxygenator. Water was recirculated through the heat exchanger of the second oxygenator via a reservoir. A myocardial temperature probe was inserted in-line 4 cm distal to the Affinity NT oxygenator arterial outlet temperature probe and was considered to measure the actual temperature of the perfusate. Temperatures were simultaneously recorded from the in-line probe, arterial outlet probe, and reservoir every second. Twenty-seven trials were run using random combinations of three Affinity NT oxygenators and three in-line probes. Each trial entailed cooling an initially normothermic reservoir to 28 degrees C and then rewarming it to normothermia again. The arterial outlet temperature probe on the Affinity NT membrane oxygenator underestimated the perfusate temperatures during early rewarming (bias of 0.72 degrees C; precision of +/-1.15 degrees C) and late rewarming (bias of 0.52 degrees C; precision of +/-0.97 degrees C). An overestimation of the perfusate temperatures occurred during early cooling (bias of -0.57 degrees C; precision of +/-1.37 degrees C). Only during the late cooling phase was the arterial outlet temperature probe accurate (bias of -0.02 degrees C; precision of +/-0.3 degrees C). The perfusionist should be aware of the temperature probe monitoring characteristics of the oxygenator to safely perfuse the patient.     

Successful management of membrane oxygenator failure during cardiopulmonary bypass--the importance of safety algorithm and simulation drills

With a high risk to time ratio, the advent of cardiopulmonary bypass has facilitated greater advances in technical procedures in cardiac surgery. This, however, has not come without its own complication risk and previous near misses have been reported with regard to various technical aspects of the cardiopulmonary bypass circuit. We present a case of a failed membrane oxygenator and discuss the real-life aspects to managing this complication without added risk to the patient.     

Development of a novel polyimide hollow-fiber oxygenator

We have developed a membrane oxygenator using a novel asymmetric polyimide hollow fiber. The hollow fibers are prepared using a dry/wet phase-inversion process. The gas transfer rates of O(2) and CO(2) through the hollow fibers are investigated in gas-gas and gas-liquid systems. The polyimide hollow fiber has an asymmetric structure characterized by the presence of macrovoids, and the outer diameter of the hollow fiber is 330 microm. It is found that the polyimide hollow-fiber oxygenator can enhance the gas transfer rates of O(2) and CO(2), and that the hollow fiber provides excellent blood compatibility in vitro and in vivo.     

Development of an Intravascular Pumping Oxygenator Using a New Silicone Membrane

Abstract: A new intravascular pumping oxygenator (IVPO) was developed for intravascular gas exchange and circulatory assistance in critically ill patients with respiratory and circulatory failure. The IVPO utilizes new silicone hollow fibers (diameter. 1 mm: membrane width, 50 μm) and consists of two driving tubes for the oxygenation and pumping of circulating blood. The performance characteristics of the IVPO were studied using an experimental ex vivo model. With a mean hemoglobin concentration of 10.5 ± 2.3 g/dl, total oxygen transfer was 5.6 ± 1.5 ml/min at a blood flow of 200 ml/min and 6.3 ± 2.2 ml/min at a blood flow of 250 ml/min. Total CO₂ transfer was 3.8 ± 1.4 ml/min at a blood flow of 200 ml/min and 4.2 ± 1.6 ml/min at a blood flow of 250 ml/min during IVPO pumping. This preliminary experiment demonstrated that the IVPO has the capacity to function both as a circulatory assist pump and as an intravascular hollow fiber oxygenator.     

Late Pathophysiologic Sequelae after Utilization of an Intravenacaval Oxygenator in Experimental Animals

Abstract: The intravenacaval hollow fiber oxygenator (IVOX) has been shown to be remarkably free from acute adverse effects on the venae cavae, right heart, and lungs when indwelling experimentally in sheep and in human clinical trial patients. However, all pathophysiologic assessments reported to date have been carried out during or immediately after IVOX utilization. It is recognized that IVOX indwelling in the venae cavae for up to 3 weeks could produce minor or unrecognized acute injury that could become more evident or more harmful after several weeks had elapsed following removal of the device. Therefore, this current study was designed and carried out to assess any pathophysiologic sequelae that could be recognized on follow–up examination 4 months after removal of an IVOX device that had been indwelling in the venae cavae for from 7 to 13 days. Extensive clinical and physiologic assessments of the blood, hemody namics, and pulmonary functional status of 8 sheep were carried out 4 months after removal of IVOX devices that had been indwelling for 7 to 13 days. Each animal was then euthanized and complete necropsy examination was conducted looking especially for gross or histologic lesions in the venae cavae, access veins, right heart, and lungs. Findings indicated that all animals were normal, without clinically or pathologically significant pathophysiologic abnormalities or adverse effects from the IVOX utilization. Detailed hematologic, hemodynamic, blood chemistry, pulmonary function, and gross and histopathologic findings, presented in graphic, tabular, and photographic form, document the conclusion that utilization of an IVOX device in normal sheep for from 7 to 13 days produces no significant adverse late pathophysiologic sequelae.