A Case Of Prolonged Deep Hypothermia During Cardiopulmonary Bypass

Observations made during and after prolonged deep hypothermia (7 hours between 6–20°C) are reported in a case operated for a rhinopharyngeal haemangioma with severe blood loss during cardiopulmonary bypass. Near normal numerical values of the acid-base parameters when corrected to the current temperature were aimed at. No organic damages could with certainty be described to the hypothermia itself or to the prolonged perfusion.     

异丙酚对低温体外循环期间脑氧合的影响

目的：观察异丙酚对低温ＣＰＢ期间脑氧合的影响。方法：心内直视手术病人２０例,随机分为对照组为异丙酚组,通过测定颈内静脉血氧饱和度（ＳｊＯ２）、动－颈内静脉血氧含量差、脑氧摄取率（ＣＥＯ２）和动－颈内静脉血乳酸含量差,分析ＣＰＢ期间脑氧合状况。结果：异丙酚组ＳｊＯ２在ＣＰＢ降温期较前升高、Ｄａ－ｖＯ２减少,复温时与降温期比较无显著变化。与对照组相比,降温和低温期差异显著。两组病人Ｄａ－ｖＬ在ＣＰＢ期     

Pyruvate Effects on Red Blood Cells During In Vitro Cardiopulmonary Bypass With Dogs’ Blood

To investigate the effects of pyruvate (Pyr) on adenosine triphosphate (ATP), endothelial nitric oxide synthase (eNOS), and nitric oxide (NO) in red blood cells (RBCs) during the cardiopulmonary bypass procedure (CPB), blood, 500 mL, was collected from each of 10 healthy dogs (weight 12–18 kg). The blood was divided into two parts (250 mL each) and randomly assigned into the control group (Group C, n = 10) or the Pyr group (Group P, n = 10). The blood was commingled with an equal volume of 0.9% NaCl and pyruvated isotonic solution (Pyr 50 mM) in the extracorporeal circuit in the two groups, respectively. The CPB procedure was fixed at 120 min, and the transferring flow was 4 L/min. Contents of ATP in RBCs, eNOS activities, and NO productions in plasma were measured before CPB and during CPB at 30, 60, 90, and 120 min in both groups. The ATP level, eNOS activity, and NO production were not different prior to CPB between the two groups. A decline of ATP levels was shown in both groups but remained significantly higher in Group P than in Group C at the same time points during in vitro CPB (P < 0.01). Values of eNOS and NO were significantly increased in Group C but markedly reduced in Group P during CPB, compared with pre‐CPB (P < 0.01). The CPB procedure significantly damaged dogs’ RBCs in the ATP level, eNOS activity, and NO production, in vitro, but Pyr effectively protected RBCs in these functions during CPB. Pyr would be clinically protective for RBCs during CPB.     

体外循环中人参二醇组皂甙的心肌保护作用

为观察人参二醇组皂甙（ＰＤＳ）对体外循环（ＣＰＢ）手术病人的心肌保护作用，将６０例ＣＰＢ手术病人，随机均分为对照组与ＰＤＳ组。ＰＤＳ组术前２天和术前３０分钟，按１５ｍｇ／ｋｇ，共３次，静脉滴注ＰＤＳ。测定两组ＣＰＢ期间（转流前、转流１５、３０分钟、再灌注１５、３０、６０分钟）血清超氧化物歧化酶（ＳＯＤ）和丙二醛（ＭＤＡ）含量。结果发现ＣＰＢ时间与ＳＯＤ活性成反比，与ＭＤＡ含量成正比。两组ＳＯＤ活性总均数ＰＤＳ组较对照组高，差异显著（Ｐ＜０．０１）；两组ＭＤＡ含量总均数ＰＤＳ组较对照组低，差异有显著性（Ｐ＜０．０１）。结论：术前应用ＰＤＳ可显著提高ＣＢＰ手术病人ＳＯＤ活性，减少ＭＤＡ生成，从而防治心肌再灌注损伤。     

Blood-Surface Interactions During Cardiopulmonary Bypass

A bstract The interaction between blood and the synthetic surfaces of the heart-lung machine activates plasma protein systems and blood cells to produce a host of vasoactive substances that mediate the "whole body inflammatory response" associated with cardiopulmonary bypass (CPB). Plasma proteins are instantaneously adsorbed onto nonendothelial surfaces; plasma factor XII is cleaved into two serine proteases; and platelets are activated to aggregate, adhere to adsorbed fibrinogen, and release granule contents. Activation of factor XII initiates coagulation by the intrinsic coagulation pathway and activates complement. Complement stimulates neutrophils to release vasoactive and cytotoxic substances. Endothelial cells, perhaps stimulated by formation of minute quantities of thrombin, produce tissue plasminogen activator, which generates plasmin, a fibrolytic enzyme. Blood becomes a stew of powerful enzymes and chemicals that alters vascular smooth muscle and endothelial cell contraction. Capillary permeability increases, fluid is retained, and function of essentially every organ is temporarily impaired. Attempts to control the morbidity of CPB have focused on reversible inhibitors of specific reactions in blood. Prostanoids and new disintegrins are promising platelet inhibitors that are reversible. Aprotinin and other serine protease inhibitors partially control fibrinolysis and activation of neutrophils. Alternatives to heparin also show promise. Eventually control of the interaction of blood and synthetic surfaces will control the adverse reactions of the heart-lung machine and reduce the bleeding, thrombotic and inflammatory complications of open heart operations.     

参附注射液对体外循环中炎性反应的影响

目的：观察参附注射液对体外循环（CPB）中肿瘤坏死因子－α（TNF－α）和白细胞介素－6（IL－6）的影响。方法：将20例人工心脏瓣膜置换术患者随机分成参附组和对照组（每组10例）。参附组分别于麻醉诱导前、CPB前及主动脉开放10分钟内分别静脉滴注参附注射液20ml、40ml和40ml，于CPB前、主动脉阻断前、主动脉阻断30分钟，主动脉开放15分钟和60分钟时采用放射免疫法测定两组血心中TNF－α和IL－6的含量。结果：主动脉阻断前、主动脉阻断30分钟、主动脉开放后15分钟和60分钟，对照组TNF－α值均明显高于参附组（P＜0．05），各时点IL－6组间比较差别无显著性意义（P＞0．05）。结论：参附注射液可降低主动脉开放后血浆TNF－α的含量，具有对抗CPB所致的炎性反应的作用，而对CPB中IL－6作用不明显。     

间断肺通气对体外循环肺损伤的保护作用

目的研究间断肺通气对体外循环(CPB)肺损伤的保护作用,并探讨其机制。方法将24例风湿性心脏病患者采用随机数字表法分为两组,处理组(n=13)CPB期间每5min间断肺通气一次;对照组(n=11)CPB期间不通气。所有患者均在术前留取血液标本,术后2h行支气管肺泡灌洗,分别测定支气管肺泡灌洗液(BALF)中的中性粒细胞、总蛋白(TP)、肿瘤坏死因子-α(TNF-α)含量、血清总蛋白以及术前、CPB后1h、4h肺氧合指数(OI)。结果处理组BALF中的中性粒细胞、TP、TNF-α含量较对照组显著降低(P<0.01,P=0.02,0.02),CPB后OI较对照组显著降低(P<0.05);两组CPB后1h、4h其OI均较同组CPB前显著增高(P<0.05)。结论间断肺通气可通过减少白细胞与血管内皮的黏附,减轻肺部炎症反应、内皮细胞损伤等,对CPB所致的肺损伤有保护作用。     

Blood Anesthesia for Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) causes bleeding and thrombotic complications, fluid retention and temporary dysfunction of every organ system. This morbidity of CPB is primarily do to activation of blood proteins and cells by contact with nonendothelial cell surfaces of the wound and biomaterials of the extracorporeal perfusion circuit. CPB is not possible without heparin, yet heparin is not an ideal anticoagulant and does not prevent activation of at least five plasma protein systems and five blood cells. Stimulation of these blood elements produces over 25 vasoactive substances that alter vascular tone, capillary permeability, and cardiac myocyte contractility. In addition, CPB produces showers of microemboli that pass filters to obstruct arterioles and precapillaries to produce necrosis of widely dispersed, small groups of cells. Attempts to develop nonthrombogenic synthetic materials have failed; only the endothelial cell is nonthrombogenic and achieves this property by active metabolic processes. Although some biomaterials are less thrombogenic than others, all activate blood elements to initiate clotting and the body's defense reaction. The concept of “blood anesthesia” envisions the use of reversible inhibitors of key blood reactions to temporarily prevent activation of blood elements during CPB. If the initial reactions of blood with nonendothelial surfaces are blocked, production of many vasoactive substances and microemboli by CPB is suppressed. This conserves blood elements that are normally consumed during CPB and makes them available after the inhibitor is reversed. Effective, reversible inhibitors of platelets are entering clinical trials; reversible inhibitors of other key blood relations are being developed and tested at a rapid rate. Within the next decade “blood anesthesia” for CPB promises to substantially reduce the morbidity associated with open heat surgery.     

L-精氨酸对体外循环病人术后血浆IL-6水平的影响及意义

目的　通过比较应用L 精氨酸与否对体外循环 (CPB)术后白细胞介素 6(IL 6)血浆浓度的影响 ,探讨L 精氨酸在CPB心脏手术中的抗炎作用。　方法　将 2 9例拟行心脏瓣膜置换手术的风湿性心脏病患者术前随机分成两组 :处理组 (n =15 ) ,术中给予L 精氨酸治疗 3 0 0mg/kg ;对照组 (n =14) ,未给予L 精氨酸。分别于术前、CPB停机后 2h、2 4h用酶联免疫吸附法测定两组血浆IL 6浓度。结果　①两组病例CPB后 2h、2 4hIL 6水平与同组术前基础值比较有显著的升高 (P <0 .0 5 ) ;②CPB后 2 4hIL 6水平 ,处理组明显低于对照组 (P <0 .0 5 )。　结论　①CPB可引起促炎症细胞因子IL 6血浆水平的显著性升高 ;②L 精氨酸可以降低CPB术后IL 6血浆水平 ,具有抗炎作用     

Serum Cefazolin Levels during Cardiopulmonary Bypass

This study was done to assess the adequacy of a regimen using cefazolin as a prophylactic antibiotic for patients undergoing open-heart operation. At the time of the preoperative medication, adult patients received 1 gm of cefazolin intramuscularly, and pediatric patients were given a dose of 20 mg per kilogram of body weight. Group I consisted of 10 adults undergoing a variety of cardiac procedures. The mean serum cefazolin level after institution of cardiopulmonary bypass was 27.36 μg/ml (range, 13.1 to 40.3 μg/ml). This level remained fairly stable throughout cardiopulmonary bypass. Group II consisted of 10 pediatric patients undergoing cardiac procedures for repair of a variety of congenital anomalies. The mean serum cefazolin level after institution of cardiopulmonary bypass was 20.01 μg/ml (range, 11.4 to 28.9 μg/ml) and remained stable for the duration of the procedure. In both groups perfusion pressure, urinary output, and body temperature did not seem to have any influence on these levels.It is concluded that the administration of one dose of cefazolin intramuscularly before operation results in an adequate and stable serum cefazolin level in patients undergoing cardiopulmonary bypass for up to three hours, possibly longer.     

新型白细胞滤器LD-1对体外循环中红细胞的保护作用

目的研究一种新型白细胞滤器LD-1在体外循环(CPB)中对红细胞的保护作用。方法将25～30kg蒙古犬12只按随机数字表法分为对照组和LD-1过滤组(LD组),每组6只。对照组不使用白细胞滤器;LD组将白细胞滤器LD-1安装于CPB的静脉回流端,在CPB开始2min后打开滤器,过滤5min。分别于CPB前、CPB10min、40min、75min、停CPB和CPB后2h取静脉血测定白细胞(WBC)数量、血浆丙二醛(MDA)、超氧化物歧化酶(SOD)和游离血红蛋白(FHB)水平,并测定红细胞脆性。结果在CPB中各时间点LD组WBC数量均显著低于CPB前(P<0.01),且明显低于对照组(P<0.05);对照组血浆SOD水平在CPB75min后显著降低,而LD组血浆SOD水平在CPB75min、停CPB及CPB后2h均显著高于对照组(P<0.05,0.01);在CPB后各时间点LD组MDA水平均低于对照组,但无统计学意义;对照组在停CPB和CPB后2h,红细胞开始溶血和完全溶血所需的氯化钠浓度明显高于LD组(P<0.05);CPB后两组血浆FHB浓度均升高(P<0.01),但LD组在CPB40min后各时点均显著低于对照组(P<0.05)。结论新型白细胞滤器LD-1在CPB中能有效去除白细胞,保存血浆的抗氧化能力,抑制氧自由基对红细胞的破坏。     

Brain Protection During Pediatric Cardiopulmonary Bypass

Improvements in peri‐ and postoperative surgical techniques have greatly improved outcomes for pediatric patients undergoing cardiopulmonary bypass (CPB) in the treatment of congenital heart defects (CHDs). With decreased mortality rates, the incidence of adverse neurological outcomes, comprising cognitive and speech impairments, motor deficits, and behavioral abnormalities, has increased in those patients surviving bypass. A number of mechanisms, including ischemia, reperfusion injury, hypothermia, inflammation, and hemodilution, contribute to brain insult, which is further confounded by unique challenges presented in the pediatric population. However, a number of brain monitoring and preventative techniques have been developed or are being currently evaluated in the practice of pediatric CPB. Monitoring techniques include electroencephalography, near‐infrared as well as visible light spectroscopy, transcranial Doppler ultrasound, and emboli detection and classification quantitation. Preventative measures include hypothermic perfusion techniques such as deep hypothermic circulatory arrest, low‐flow CPB, blood gas management, and pharmacologic prophylaxes, among others. The present review summarizes the principles of brain insult, neurodevelopmental abnormalities, monitoring techniques, methods of prevention, as well as preexisting morbidities and risk factors in pediatric CPB, with a focus on brain protection. Clinical and translational research is presented with the aim of determining methods that may optimize neurological outcomes post CPB and guiding further study.     

Myocardial Antioxidant Defenses During Cardiopulmonary Bypass

A bstract In 31 male patients undergoing coronary bypass surgery who underwent different periods of cardioplegic hypothermic arrest, the activities of glutathione peroxidase, glutathione reductase, glutathione transferase, copper/zinc-containing and manganese-containing super-oxide dismutases, and catalase were studied in the right atrial myocardium, before and 5 minutes after aortic cross-clamping. The levels of thiobarbituric acid reactive substances (TBARS) and nonproteic thiol compounds (NP-SH) were also assessed. Prolonged ischemia followed by reperfusion induced activation of the major myocardial antioxidant enzymes with marked NP-SH depression and TBARS increase, despite cold crystalloid cardioplegic protection. These changes were significantly related to the duration of the ischemic arrest, suggesting: (1) that reperfusion free radical generation is dependent on the severity of the previous ischemic period; and (2) the occurrence of myocardial oxidative stress during cardiopulmonary bypass.