Comparative study of the protective effect using hypothermic cardiopulmonary bypass and normothermic cardiopulmonary bypass

Objective To explore the detrimental influence of normothermic and hypothermic cardiopulmonary bypass during open-heart surgery on immunity function,cytokines and complements.Methods Forty patients with congenital or rheumatic heart disease were randomized to receive the two strategies:normothermic CPB(study group)and hypothermic CPB(control group),20 cases in each group.Venous blood samples were collected at each time points of preoperation,end of CPB,day 1,4,7,14 postoperatively to examine the plasma level of IL-2,TNF-α,C3,C4,IgG,IgM,IgA,CD3,CD4,CD8.Results IL-2 in both groups decreased significantly at day 1,4,and returned to normal at day 7 postoperatively.IL-2 in control group was significantly lower than that in study group postoperatively.TNF-α in two groups was all higher at time points of end of CPB,day 1,4 postoperatively;in study group,it returned to normal level at day 7 postoperatively,whereas in control group,it was still higher at day 7 postoperatively than that before operation,and returned to normal at day 14 postoperatively.C3 in study group was significantly lower at time points of end of CPB,day 1,7 postoperatively than that in control group;C3 in both groups was all higher at time points of end of CPB,day 1,4 postoperatively;in study group,it returned to normal level at day 7 postoperatively,whereas in control group,it was still higher at day 7 postoperatively than that before operation and returned to normal at day 14 postoperatively.C4 in study group at time points of end of CPB,day 1 postoperatively was significantly lower than that in control group;C4 in both groups was all lower at time points of end of CPB,day 1,4 postoperatively than that before operation.The results showed that IgA after operation in both groups was significantly lower than that before operation,and returned to normal at day 7 postoperatively;IgA in study group at day 1 postoperatively was higher than that in control group.IgG in both group at time points of end of CPB,day 1,4 postoperatively was significantly lower than that before operation.IgG in control group was significantly higher at time points of end of CPB,day 1,4 postoperatively was significantly higher than that in control group.IgM in study group was significantly lower at time points of end of CPB,day 1,4 postoperatively.In control group,IgM was significantly lower at time points of end of CPB,day 1,4,7 postoperatively and returned to normal at day 14 postoperatively.IgM in study group was significantly higher at day 1,4 postoperatively than that in control group.CD3,CD4 in both groups decreased significantly at time points of end of CPB,day 1,4,and CD3、CD4 in study group and CD3 in control group returned to normal at day 7 postoperatively,CD4 in control group still lower than that before operation at day 7 postoperatively,and returned to normal at day 14 postoperatively.CD3,CD4 in control group was significantly lower at time points of end of CPB,day 1,4 than that in study group.CD8 in both groups increased significantly at day 1 postoperatively;there was no significant difference between the two groups.Conclusions The detrimental influence of open-heart surgery under normothermic CPB on humoral and cellular immunity function,cytokines and complements is less than that under hypothermic CPB,so normothermic CPB is beneficial for the postoperative recovery and anti-inflammation function.     

Hemoglobin substitute and cardiopulmonary bypass

The effects of diaspirin crosslinked hemoglobin (DCLHb, Baxter Health Care Corp., Round Lake, IL) on oxygen exchange in the setting of cardiopulmonary bypass (CPB) are unknown. Six calves (71.2 +/- 1.3 kg) were connected to CPB by jugular venous and carotid arterial cannulation for 5 hours. Each 1 hour period included 45 min of partial CPB (mean flow rate of 50 ml/kg per min) followed by 15 min without CPB, at the end of which 500 ml of blood were substituted for with either 500 ml of hydroxyethyl starch (Haes; n = 3) or 500 ml of DCLHb (n = 3). A total of 2 liters of blood was, thus, exchanged (28 ml/kg of blood substitute). Values are expressed as mean +/- 1 SD. Analysis of variance for repeated measurements was used. The cardiac output (CO) values at 1 h, 3 h, and 5 h were in the Haes group: 5.7 +/- 2, 6.7 +/- 2.5, and 7.7 +/- 2.5L/min, and in the DCLHb group: 5.7 +/- 0.6, 4 +/- 1, and 4.7 +/- 1.2 L/min, respectively. The arteriovenous oxygen content difference (Ca-Cvo2) values at 1 h, 3 h, and 5 h were in the Haes group: 4.6 +/- 1, 3.3 +/- 1.5, and 3.5 +/- 1.5 ml/dl, and in the DCLHb group: 4.9 +/- 0.6, 7.4 +/- 0.7, and 6.6 +/- 0.6 ml/dl, respectively. The oxygen consumption (Vo2) values at 1 h, 3 h, and 5 h were in the Haes group: 244 +/- 29, 198 +/- 58, and 249 +/- 42 ml/min, and in the DCLHb group: 273 +/- 28, 296 +/- 75, and 306 +/- 65 ml/min, respectively. CO and Ca-Cvo2 showed a significant difference (p < 0.01), whereas Vo2 did not (p = 0.52). In the DCLHb group of this CPB animal model, the cardiac output is lower and the arteriovenous oxygen content difference higher than in the Haes group, allowing for preserved oxygen consumption.     

Antioxidant trace element reduction in an in vitro cardiopulmonary bypass circuit

Many complications occurring after cardiac surgery are attributed to an acute increase in reactive oxygen and reactive nitrogen species, which under normal conditions are balanced by the antioxidant response. Two key enzymes of the antioxidant response, glutathione peroxidase (GPx) and superoxide dismutase (SOD), rely on trace elements for normal function. It was hypothesized that circulation of blood through the cardiopulmonary bypass (CPB) circuit would 1) reduce trace element levels and antioxidant function, 2) increase oxidative stress, and that 3) prepriming circuits with albumin would ameliorate trace element loss. This hypothesis was investigated by circulating fresh human whole blood in an in vitro CPB circuit. Plasma selenium, copper, and zinc levels were measured, as were SOD and GPx and oxidative stress by thiobarbituric acid reactive substances (TBARS). In spite of significant decreases in copper and zinc levels, SOD levels increased with time. Significant decreases in selenium were associated with a trend to increase TBARS but no change in GPx. Prepriming with albumin provided no benefit as it did not reduce trace element loss nor alter levels of oxidative stress. This study confirms that CPB circuits cause significant depletion of trace elements (selenium, copper, and zinc) necessary to maintain redox homeostasis. The loss of trace elements is a potential contributor to cardiac surgical morbidities, and further studies in the cardiac patient population are needed to investigate this.     

Pediatric cardiopulmonary bypass devices: trends in device use for cardiopulmonary bypass and postcardiotomy support

Cardiopulmonary bypass (CPB) devices and techniques have continuously evolved. We have conducted surveys that chronicle the changes in CPB devices and techniques used at North American pediatric cardiac surgery centers since 1989. The aim of this article is to describe trends in cardiopulmonary bypass device use during cardiac surgery and changes in the devices used for extracorporeal life support (ECLS) following cardiac surgery for pediatric patients. The diffusion of innovation in pediatric cardiovascular surgery has not been solely driven by the availability of scientific evidence to support change but rather it has often been related to other factors that influence clinicians willingness to change including; tradition, ease of use, and cost related pressures. The current CPB systems used for cardiac surgery are more homogenous than in previous years. Most centers use a heparin coated or modified surface system comprised of a "hard shell" open venous reservoir, a roller pump, a hollow fiber membrane oxygenator, and arterial line filter. ECLS systems comprised of hollow fiber oxygenators and centrifugal pumps for are gradually replacing the classical ECLS circuit, servo regulated roller pumps and silicone rubber membranes. Nearly 40% of centers use these alternate components in their ECLS systems. Costs, utility, safety and measurable benefit to the patient should guide decisions related to device selection.     

对体外循环技术的一些认识和思考

体外循环（Extracorporeal circulation,ECC）,也称心肺转流（Cardiopulmonary bypass,CPB）,是指将回心血液引流至体外,经特殊装置使血液氧合并交换出二氧化碳后再回输人体,从而实现完全或部分代替心脏和肺的循环呼吸功能的复杂的技术过程。体外循环技术的诞生开创了现代心血管外科学的新纪元,其发展和完善促进了心脏和血管疾病外科治疗的快速发展和进步。     

Successful removal of an infected pacemaker lead using cardiopulmonary bypass in an 89-year-old patient

We report the case of an 89-year-old patient suffering from endocarditis with septicemia caused by a growth on a pacemaker lead. The entire pacemaker system was successfully removed using cardiopulmonary bypass. Although the patient was an octogenarian in poor condition with a systemic infection, an aggressive operation with careful perioperative management gave a good clinical result. As far as we know, this is the oldest patient in whom a pacemaker system has been removed using cardiopulmonary bypass.     

Fluid distribution kinetics during cardiopulmonary bypass

OBJECTIVE:

The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass.

METHODS:

Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer''s acetate 1470 ml and mannitol 15% 200 ml) and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT01115166","term_id":"NCT01115166"}}NCT01115166.

RESULTS:

The distribution half-time of Ringer''s acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean) at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (p<0.02). The mass balance of sodium indicated a translocation from the intracellular to the extracellular fluid space in 8 of the 10 patients, with a median volume of 236 ml.

CONCLUSIONS:

The distribution half-time of Ringer''s solution during isovolumetric cardiopulmonary bypass was 8 minutes, which is the same as for crystalloid fluid infusions in healthy subjects. The intravascular albumin mass increased. Most patients were hypovolemic prior to the start of anesthesia. Intracellular edema did not occur.     

体外循环后全身炎性反应

全身炎性反应(SIRS)是体外循环手术后的常见并发症.体外循环中由于血液与体外循环装置中的气体界面及管道的作用,启动三个相交的血浆蛋白酶旁路的激活,这些旁路包括激肽-激肽释放酶系统、凝血-纤溶系统、补体系统,通过一系列的蛋白分解产生活化的致炎性介质,激活白细胞、内皮细胞及血小板,促使血管扩张及通透性增加.激活的细胞成分能分泌炎性介质包括细胞因子,增强这一反应过程,最终导致组织损伤及器官功能失调.     

Altered lymphocyte subsets during cardiopulmonary bypass

Peripheral blood lymphocyte subsets were quantified by immunofluorescence in nine patients undergoing open heart surgery for coronary artery, valvular, and congenital heart disease. Compared with normal preoperative values, all patients developed an absolute lymphopenia, a reduction in T4 (helper) lymphocytes, and a statistically significant reversal of the T4/T8 ratio two hours after cardiopulmonary bypass (CPB). These changes could be caused by mechanical or immunogenic injury. A return to normal of the T4 subset and T4/T8 proportion occurred 24 hours after surgery. Whereas transient inactivation of immunoreactive lymphocyte clones may prevent unwanted immunization to blood products received during surgery, such temporary immune dysfunction could make certain patients liable to infectious sequelae. Viral-induced postperfusion syndromes, transmission of human T lymphotropic virus (HTLV) III by blood products, and reports of acquired immune deficiency syndrome after CPB foster a concern regarding postoperative infections under these circumstances.     

体外循环中的肝素涂层技术

肝素涂层技术是改进医疗设备血液、生物相容性的一种方法 ,首先应用于体外循环设备中。目前在美国及欧洲一些国家已经广泛应用于临床 ,取得了良好效果。本文针对肝素涂层技术的原理、实验研究、临床应用以及商品化设备等方面做一综述 ,并展望了肝素涂层技术的应用前景     

Nonocclusive mesenteric ischemia after cardiopulmonary bypass

Nonocclusive mesenteric ischemia (NOMI) is a rare abdominal pathology caused by mucosal hypoperfusion without actual obstruction to the mesenteric arteries. We present a case of NOMI after a cardiopulmonary bypass operation. The patient was a 79-year-old woman with a history of hypertension and diabetes mellitus. A coronary bypass operation was performed with stable hemodynamic conditions, and continuous venovenous hemodialysis was performed on the second postoperative day because of renal insufficiency. After 24h of hemodialysis, the hematocrit level increased from 29.1% to 36.1%. The patient had some vague abdominal pain on the third postoperative day with abnormal laboratory values: leukocytes 17.10 × 10³/µl, creatine kinase 1085U/l, glutamic-oxyloacetic transaminase 6188U/l, and lactate dehydrogenase 8695U/l. Selective angiography showed diffuse stenosis of the superior mesenteric artery (SMA) without any occlusive findings on the major branches; the patient was therefore diagnosed with NOMI. An infusion of urokinase and prostaglandin E1 was started; however, disseminated intravascular coagulopathy had developed and the patient died on the 21st postoperative day as a result of multiple organ failure. The autopsy demonstrated extensive necrosis and hemorrhage in the small intestine without any occlusive findings on the major branches of the SMA.     

体外循环管理中的感染监测

体外循环（cardiopulmonary bypass,CPB）是心脏外科手术中的一个重要环节。体外循环管理工作均在手术室中进行,而手术室是感染的高危科室之一,从事体外循环工作的医务人员除了做好体外循环灌注管理外,还应做好体外循环期感染监控的工作[1]。我科长期以来规范无菌物品监管制度,     

体外循环肺部炎症反应的研究

目的：探讨体外循环过程中应用丝裂原激活蛋白激酶的特异性阻滞剂后观察肺组织损伤程度的变化及对术后肺功能的影响。方法：将18只乳猪随机分为3组，每组6只。实验组（Ⅱ组）体外循环术中用P38丝裂原激活蛋白激酶（p38MAPK）的特异性阻滞剂（SB203580）行肺灌注；Ⅰ组、Ⅲ组为对照组。分别在不同时段取三组动物的肺脏标本，以免疫印迹方法测量肺组织p38MAPK活性。组织学观察肺损伤改变，测量肺组织干湿重比，术后采集动脉血行血气分析，估测肺换气功能。结果：Ⅰ组p38MAPK活性明显增高，Ⅰ组肺损伤与Ⅱ、Ⅲ组相比明显加重。肺换气功能Ⅱ组好于Ⅰ组。结论：体外循环过程中，应用p38MAPK特异性阻断剂有抑制肺损伤的作用，改善术后肺功能。