Haemodynamic effects of heparin during coronary bypass surgery

Heparin has been suggested as an activator of the plasma kallikrein-kinin system, with possible formation of bradykinin, a potent vasodilator. Haemodynamic effects and changes in the kallikrein-kinin system were studied after heparin- and saline-injections in ten patients undergoing coronary bypass surgery. A moderate decrease in mean arterial pressure was found in all patients in the observation period, but significantly more at 2 and 3 min after heparin-injection compared with saline-injection. None of the other haemodynamic variables measured were significantly different when comparing heparin- to saline-injection. Heparin-injection resulted in significant changes in the kallikrein-kinin system, with a marked increase in spontaneous kallikrein-like activity as the most prominent feature, while no changes were found after saline-injection. Liberation of bradykinin would be expected to give a decrease in systemic vascular resistance with an increase in cardiac output. The results indicate that the plasma kallikrein-kinin system, though apparently activated after heparin-injection, does not contribute significantly to the decrease in arterial pressure in the patients studied.     

非体外循环冠脉搭桥术中心脏移位对血液动力学的影响

目的 观察非体外循环冠脉搭桥术(OPCABG)中暴露术野时心脏位置改变对心血管功能的影响。方法 冠心病多支病变患者47例,年龄50～82岁,术前左室射血分数为0.55±0.14,择期行OPCABG,平均移植血管桥3.2条。采用漂浮导管方法监测血液动力学,分别在麻醉诱导后循环稳定时(T_1)、搬动心脏前(T_2)、吻合前降支时(T_3)、吻合右冠状动脉或后降支时(T_4)、吻合左旋支或对角支时(T_5)、血管吻合完成、心脏恢复自然位置后(T_6)、及手术结束时(T_7)作参数测定。结果 吻合前降支时(T_3),SI和LVSWI有所降低(P<0.01),但CI和SvO_2保持在基础水平。吻合后降支或右冠状动脉、左旋支或对角支时(T4、T5),CI、SI、LVWI、LVSWI、RVWI和RVSWI等明显降低(P<0.01),其中CI较对照值降低18％,LVWI和RVWI降低均为25％,MAP和SvO_2也显著下降(P<0.05～0.01),而HR、RAP、MPAP、PAWP和PVRI则显著增高(P<0.05～0.01)。心脏恢复自然位置后(T_6),CI、LVWI和RVWI恢复到对照值水平。结论 OPCABG术中由于心脏被搬动及移位,可导致明显的心功能损害和血压下降;麻醉手术期间采取可靠的血液动力学监测和有效的心血管功能支持十分必要。     

心肺转流围术期血浆肝素浓度的变化

目的　心肺转流 (CPB)围术期血浆肝素浓度的变化及其与抗凝监测、肝素中和及肝素反跳的关系。方法　 10例成人CPB心脏手术病人 ,于麻醉后肝素前、肝素 1、2、3、4、5、10min、CPB前、CPB后 5、10、30min、停机、中和 1∶0 5、1∶0 75、1∶1、中和结束及术后 1～ 6h采血。分别测定血浆肝素浓度 (应用发色底物抗Xa方法 ) ,激活部分凝血致活酶时间 (APTT)、凝血酶时间 (TT)及激活全血凝固时间 (ACT)。结果　静注肝素 (4 0 0U/kg)后 1min血浆浓度达高峰为 (6 4 6± 1 0 5 )U/ml,到CPB开始时为 (4 2 8± 0 30 )U/ml,停机时为 (2 82± 0 4 1)U/ml。CPB前血浆肝素浓度与ACT显著相关 (r =0 896 ,P <0 0 1)。首次中和 (比值为 1∶0 5 )后肝素浓度为 (0 12± 0 10 )U/ml。术后 3～ 4h肝素浓度重新升高 (与基础值相比P <0 0 1) ,但与ACT、APTT及TT均无相关性 (P >0 0 5 )。结论　CPB前ACT能可靠监测肝素抗凝 ;CPB后鱼精蛋白首次按 1∶0 5已基本能中和游离的肝素 ;总比例 1∶1 5后 ,无肝素反跳     

Predictors of inotropic support during weaning from cardiopulmonary bypass in coronary artery bypass grafting surgery

Early or prophylactic inotropic drug administration is occasionally required to facilitate separation from cardiopulmonary bypass (CPB) in cardiac surgery. However, it is not without untoward effects and should be conducted on the basis of rational criteria. The purpose of our study was to clarify variables associated with the requirement for inotropic support during separation from CPB and to testify whether pre-CPB left ventricular (LV) function, as evaluated by transesophageal echocardiography (TEE), is one of the significant variables. Clinical profile data and TEE findings were retrospectively analyzed for 91 patients who had received elective primary isolated coronary artery bypass grafting (CABG) surgery. Post-CPB inotropic drug administration initiated prior to aortic decannulation was considered inotropic support for terminating CPB. Stepwise multiple logistic regression analysis identified pre-CPB LV regional wall motion abnormalities (RWMA), NYHA class, age, and duration of CPB (in order of significance) as factors associated with inotropic support for discontinuing CPB. Pre-CPB LV enddiastolic area or fractional area change was not a significant variable in the multivariate model. Our result suggests that evaluation of pre-CPB LV RWMA is useful in predicting the need of inotropic intervention during separation from CPB in patients undergoing CABG surgery. This study was performed at The Weiler Hospital of The Albert Einstein College of Medicine, and was presented in part at the 17th annual meeting of The Society of Cardiovascular Anesthesiologists, Philadelphia, Pennsylvania, May 8–10, 1995     

Effects of atorvastatin on arterial endothelial function in coronary bypass surgery

Objective: Endothelial dysfunction represents a critical early component of organ injury following cardiopulmonary bypass. Recent studies demonstrate that the treatment with atorvastatin is associated with a significant improvement of endothelial function independently of its efficacy on cholesterol levels. Therefore, we investigated the effects of preoperative atorvastatin treatment on endothelium function after coronary surgery. Methods: Forty patients undergoing coronary surgery were randomized to treatment with atorvastatin (20 mg/die; N = 20) or placebo (N = 20) 3 weeks before surgery. Twenty normal patients served as control group. The flow-mediated dilations (FMD) of the brachial artery after both reactive hyperemia (endothelium dependent) and nitroglycerin administration (endothelium independent) were evaluated at baseline, at 48 h, and 5 days postoperatively. Results: At baseline, the endothelium-dependent FMD was significantly attenuated in coronary versus normal patients (normal 10.3 ± 1.8% vs coronary 4.1 ± 1.6%, p < 0.01). At 48 h postoperatively all patients exhibited a reduced FMD compared with baseline values: the endothelium-dependent dilatation showed a drop of 60.1 + 15% in the patients of the placebo group compared with 45.8 + 16.6% (p < 0.05) those in the atorvastatin group. At the univariate analysis, no significant correlation was found between serum levels of either total cholesterol or HDL cholesterol and FMD. The nitroglycerin-induced dilation was not significantly influenced by extracorporeal circulation as well as by atorvastatin treatment. Conclusions: The endothelial dysfunction following cardiopulmonary bypass is improved by the treatment with atorvastatin, by a mechanism unrelated to the drug efficacy of controlling serum cholesterol levels.     

体外循环与非体外循环冠状动脉旁路移植术补钾影响因素的比较

目的 探讨常规冠状动脉旁路移植术(CCABG)与非体外循环冠状动脉旁路移植术(OPCABG)围术期钾离子变化特点与补钾影响因素.方法 50例接受CABG患者,分为CCABG组和OPCABG组,每组25例.术中根据血气结果补钾,维持血清钾离子浓度在4.0～5.0mmol/L.记录并比较两组术中及术后液体出入量、补钾量、单位时间补钾量(补钾量/手术时间)、尿钾浓度、尿排钾量(总尿量×平均尿钾浓度)以及心肺转流(CPB)指标,分析两组术中补钾量的独立影响因素.结果 CCABG组术中补钾量及单位时间补钾量均高于OPCABG组,但其CPB前后单位时间补钾量低于OPCABG组(P＜0.05);CCABG组桥血管数、手术时间、术中尿量、尿排钾量及术后24 h补钾量均大于OPCABG组,术中平均尿钾浓度和最低体温低于OPCABG组(P＜0.05).多元线性回归分析显示尿量和入室血钾浓度是OPCABG组术中补钾量的独立影响因素;年龄和CPB转机时间是CCABG组术中补钾量的独立影响因素(P＜0.05).结论 CABG围术期需积极补钾.OPCABG中应根据基础血清钾水平结合尿量尽早开始补钾;CCABG中应根据CPB时间合理补钾.     

Normothermic cardiopulmonary bypass and cardioplegia reduce inotropic requirements and creatine kinase-MB after coronary artery bypass graft surgery

Purpose To determine whether normothermic cardiopulmonary bypass (CPB) and cardioplegia preserve myocardial function, reduce inotropic requirements, and reduce markers of myocardial ischemia following coronary artery bypass graft surgery (CABG). Methods We retrospectively reviewed the charts of 171 consecutive patients undergoing elective CABG by a single surgeon from April 1994 to December 1995. Hypothermic CPB with intermittent cold cardioplegia was used in 83 patients and normothermic CPB with intermittent warm cardioplegia in 88 patients. Demographic, surgical, hemodynamic, and inotropic requirements and laboratory data were reviewed. Results The duration of CPB was significantly shorter in the normothermic group (113±27vs 90±21 min;P<0.0001). After CPB the cardiac index was similar between groups, but significantly larger doses of both dopamine and dobutamine were required (8vs 5μg·kg⁻¹·min⁻¹,P<0.0001), and significantly more patients required norepinephrine administration in the hypothermic group (18%vs 6%;P=0.01). Postoperative peak values of creatine kinase MB fraction (CK-MB) were significantly lower in the normothermic group (80±60vs 55±54 IU·I⁻¹;P<0.0001). Conclusion Normothermic CPB and cardioplegia reduce inotropic requirements and CK-MB following CABG.     

尼卡地平或乌拉地尔在冠状动脉旁路移植术转流中控制血压效果的研究

目的　比较尼卡地平或乌拉地尔在体外循环中控制血压的效果及其对血液动力学的影响。方法　 60例冠状动脉旁路移植术 ( CABG)病人在体外循环 ( CPB)中平均动脉压 ( MAP)升至80 mm Hg( 1k Pa=7.5 mm Hg)时接受尼卡地平或乌拉地尔治疗。60例病人随机分为尼卡地平组或乌拉地尔组 ,每组 3 0例 ;另设同时期同类病人 3 0例作为对照组。观察两药起效时间 ,维持 MAP在 ( 70±5 ) mm Hg所需剂量 ,降压期间对人工肺血面的影响 ,停机后的血液动力学及混合静脉血氧饱和度( SvO2 )变化。结果　将 MAP从 80 m m Hg降至 70 m m Hg,应用尼卡地平 4μg· kg- 1 · min- 1 所需时间为 ( 2 .4± 1.1)分 ,维持 MAP在 ( 70± 5 ) m m Hg所需剂量为 ( 1.1± 0 .5 ) μg·kg- 1· m in- 1。应用乌拉地尔 90 μg· kg- 1· min- 1所需时间为 ( 2 .8± 1.0 )分 ,维持 MAP在 ( 70± 5 ) mm Hg所需剂量为 ( 5 0 .8±14 .4 ) μg· kg- 1· min- 1 ,但有 2例耐药 ,需不断增加剂量方能控制血压。尼卡地平组 19例 ( 63 % ) ,乌拉地尔组 2 2例 ( 73 % )心脏自动复跳 ,两组的自动复跳率均高于对照组 ( 4 6.2 % ) ( P<0 .0 5 ) ,但两组之间无差异 ( P>0 .0 5 )。停机后两组外周阻力 ( SVR)较 CPB前均明显下降 ( P<0 .0 1) ,每搏量 ( SV)     

瑞芬太尼预处理对冠状动脉旁路移植术患者体外循环期间的脑保护作用

目的 探讨瑞芬太尼预处理对冠状动脉旁路移植术患者体外循环期间的脑保护作用.方法 择期行体外循环(CPB)冠状动脉旁路移植术的患者40例,ASA Ⅱ或Ⅲ级,随机分为4组(n=10):对照组(C组)和不同剂量瑞芬太尼预处理组(R_(1～3)组).R_(1～3)组于麻醉诱导后30 min时分别静脉输注瑞芬太尼0.6、1.2和1.8 μg·kg~(-1)min~(-1),输注时间5 min,重复3次,间隔5 min;C组以生理盐水代替瑞芬太尼.于麻醉诱导前(T_0)、CPB开始前(T_1)、CPB 30 min(T_2)、CPB结束(T_3)时取颈内静脉血样3 ml,采用ELISA法测定血浆S-100β蛋白浓度,采用比色法测定血浆超氧化物歧化酶(SOD)活性和丙二醛(MDA)浓度.结果 与T_0时比较,T_(1～3)时各组血浆S-100β蛋白和MDA浓度升高,SOD活性降低(P<0.05或0.01);与C组比较,R_3组T_(2,3)时血浆S-100β蛋折和MDA浓度降低,SOD活性升高(P<0.05),R_1组和R_2组上述指标差异无统计学意义(P>0.05).结论 瑞芬太尼(1.8μg·kg~(-1)min~(-1))预处理可减轻冠状动脉旁路移植术患者CPB诱发脑损伤,其机制可能与抑制脑脂质过氧化反应有关.     

Plasma fibronectin and complement activation in coronary bypass surgery

In patients with severe sepsis, plasma fibronectin concentrations are reduced and complement is activated. It is not known whether complement activation interferes with plasma fibronectin. Cardiopulmonary bypass is known to activate complement. We have therefore used this operation to study the effect of complement activation on plasma fibronectin in the absence of sepsis. After 15 min of bypass the percentage changes of plasma fibronectin and haematocrit were similar (65.9 +/- s.e.m. 4.8 and 67.0 per cent +/- s.e.m. 2.3, respectively), but the changes in C3 and C5 (58.4 +/- s.e.m. 4.8 per cent and 52.5 per cent +/- s.e.m. 2.1) were significantly greater than those of the haematocrit, indicating complement consumption. During the first 60 min of bypass there was a significant increase in the neutrophil count which is compatible with complement activation. It is unlikely that complement activation alone, in the absence of sepsis, contributes to the reduction of plasma fibronectin concentrations.     

非体外循环冠状动脉搭桥手术的麻醉方法及血液动力学和氧代谢的变化

目的 观察非体外循环冠状动脉搭桥手术的麻醉方法、术中病人血液动力学和氧代谢的变化以及术后病人的早期.非体外循环冠状动脉搭桥手术闰人20例，麻醉用咪唑安定0.1-0.2mg/kg、芬太尼15－30μg/kg及0.5%-2%的吸入麻醉药等，在切皮前、开心包后、心脏操作中、操作完成后10min及术毕观察血液动力学指标及脑氧饱和度，同时采集桡动脉和肺动脉血，测定血气及动脉血乳酸（ABL），计算氧供DO2）、氧耗（VO2）和氧摄取率（ERO2）。术后早期观察术后拔除气管插管、ICU停留及术后住院时间、并发症及死亡等情况。结果 心脏操作中MAP、SV、SI下降，HR、CVP升高，MAP下降以搭回旋支时最明显（P＜0.01），HR升高以搭右冠时最明显（P＜0.01）；心脏操作中DO2降低（P＜0.05），VO2无变化，ERO2升高（P＜0.01）；操作后DO2、ERO2恢复至操作前水平；操作后ABL升高（P＜0.01）。结论 本组麻醉方法使病人完全度过非体外循环搭桥术，在心脏操作期易出现血压、每搏量、心指数下降，伴心率、静脉压升高，但时间短暂无严重后果，氧代谢紊乱及缺氧程度较轻。     

Metabolic changes and clinical outcomes in patients undergoing on and off pump coronary artery bypass surgery

Objective Though the advent of cardiopulmonary bypass saw a dramatic increase in the number of coronary bypass surgeries performed annually, a few surgeons continued to use off pump technique mainly for economic reasons. But the adverse effects of cardiopulmonary bypass necessitated a relook at the off pump technique. The study aims to assess the metabolic changes and clinical outcomes in patients undergoing on or off pump coronary bypass surgery. Methods One hundred patients with severe left ventricular dysfunction undergoing coronary bypass surgery on or off pump, fifty in each group, were studied for the metabolic changes and clinical outcomes. The results were statistically analysed using student’s t test. Results The off pump group showed better postoperative renal function, and less incidence of lactic acidosis and oxidative stress than the cardiopulmonary bypass group. The former also had lesser need for ventilator support, shorter intensive care and hospital stay. Conclusions The off pump technique is associated with reduced myocardial injury, inflammatory response, and postoperative morbidity. This study was supported by a financial grant from Rameshwardas Birla Smarak Kosh, and Dr. P.K. Sen Research Society, Mumbai.     

体外循环下心脏手术肺保护策略

背景 肺损伤是心脏手术体外循环(cardiopulmonary bypass,CPB)的主要并发症之一,肺保护一直是临床、实验研究热点.目的 为CPB下心脏手术肺保护提供参考.内容 就近年来心脏手术CPB期间通气策略和麻醉药物、CPB设备和技术、肺动脉灌注技术、药物干预对肺保护作用的进展进行综述.趋向 CPB下心脏手术...     

心内直视手术期间血浆P物质的变化

目的：了解血浆Ｐ物质（ＳＰ）在心内直视手术期间的水平变化。方法：采用放免法对１２例心内直视手术患者的血浆ＳＰ浓度分别在麻醉前、麻醉后、转机前、转机中、转机后、术毕及术后第二天七个时间点进行了动态观察。结果：在体外循环期间血浆ＳＰ水平非常显著高于麻醉前基础值（Ｐ＜０．０１）。结论：ＳＰ参与了体外循环心内直视手术期间心血管活动的调节。     

冠状动脉搭桥术后血浆可溶性Fas及其配体的变化

目的比较在心肺转流（CPB）或非CPB下冠状动脉搭桥术（cABG）后可溶性Fas（sFas）和可溶性Fas配体（sFasL）的血浆浓度变化。方法19例病人分别在CPB（CPB组，n=9）或非CPB（非CPB组，n=10）下行择期cABG。术前、术毕和术后取血测定白细胞介素-6（IL-6）、中性粒细胞弹性蛋白酶、sFas、sFasL血浆浓度。结果术毕、术后4h的IL-6和术毕、术后4、12h的中性粒细胞弹性蛋白酶非CPB组明显低于CPB组（P〈0．05或P〈0．01）。CPB组的sFas在术后4、12h明显升高（P〈0．05或P〈0．01），非CPB组在术后12h明显升高（P〈0．01），术后24h恢复至术前水平。两组的sFasL在术毕和术后4、12h均明显升高（P〈0．05或P〈0．01），术后24h恢复至术前水平；其中术后12h非CPB组明显低于CPB组（P〈0．05）。结论CPB或非CPB下行cABG均导致sFas和sFasL血浆浓度升高，但CPB的应用使sFasL血浆浓度升高得更多。sFasL血浆浓度可反映机体炎性反应的程度。     

冠状动脉搭桥术患者围手术期皮质醇昼夜人泌节律与神经心理状态的研究

目的研究冠状动脉搭桥术患者围手术期皮质醇昼夜节律变化与神经心理状态的关系.方法选择在低温体外循环或非体外循环下行冠状动脉搭桥术的男性患者40例,分为体外循环组和非体外循环组,每组20例.在术中特定时点和术后每3 h抽血1次持续到术后24 h.用放射免疫法检测血浆皮质醇的含量.于术前1 d、术后7～10 d及术后3个月,应用抑郁自评量表、焦虑状态/特性询问表和神经心理量表评估抑郁和焦虑程度以及认知功能.结果术后24 h体外循环组和非体外循环组分别有3例和7例患者表现为昼夜节律性分泌,其余患者则无昼夜节律性分泌.体外循环组和非体外循环组患者术后抑郁评分高于术前(P<0.01),而体外循环组患者术后7～10 d焦虑状态显著重于非体外循环组患者(P<0.05);体外循环组患者的数字广度测验(逆向)评分低于非体外循环组患者(P<0.05);斯特鲁字色干扰测验的改正反应和阻塞反应较非体外循环组患者显著减退(P<0.05).体外循环组患者术后皮质醇昼夜分泌节律紊乱与抑郁程度和斯特鲁字色干扰测验的改正反应相关, 而非体外循环组患者皮质醇分泌节律紊乱则与抑郁程度、数字广度测验(顺向)、符号数字模式测验和斯特鲁字色干扰测验的改正反应相关.抑郁程度与认知功能的某些项目相关.结论冠状动脉搭桥术患者围手术期皮质醇昼夜分泌节律紊乱,这种紊乱直接或通过情感状态间接与认知功能相关.     

Antiinflammatory effect of heparin-coated circuits with leukocyte-depleting filters in coronary bypass surgery

Cardiac surgery with cardiopulmonary bypass is associated with a systemic inflammatory response. We examined combined use of heparin coating of the cardiopulmonary bypass circuit and a leukocyte-depleting arterial line filter to reduce this response. Thirty patients were allocated randomly to equal groups with a conventional circuit and arterial line filter (C group), a heparin-coated circuit with a conventional filter (H group), or a heparin-coated circuit with a leukocyte-depleting arterial line filter (HF group). Cytokines and respiratory function were repeatedly measured perioperatively. Plasma interleukin (IL)-6 concentrations in the HF group were lower than in the C group immediately following bypass and operation, at 4 h, and 12 h (p < 0.05). Plasma IL-8 was lower in the HF group than in the C group at 4 h (p < 0.05). The respiratory index was lower immediately after bypass in the HF group than the C group (0.61 +/- 0.2 versus 1.05 +/- 0.4, p < 0.05). Heparin-coated circuits with leukocyte-depleting filters decrease inflammatory responses and improve pulmonary function during operation.