Improved hemostasis with the combination of a heparin-coated circuit and aprotinin prime during open-heart surgery: potentiating effect on platelet preservation

Aprotinin administration with or without a heparin-coated circuit is expected to modulate subclinical plasma coagulation and fibrinolysis and platelet function during cardiopulmonary bypass. We studied the effect of the application of both, either one, or neither of an aprotinin prime (100 million KIU) and heparin-coated circuit in 32 consecutive patients undergoing coronary artery bypass surgery randomly divided into four groups of 8 patients each. Aprotinin was not used with the non-heparin-coated circuit in the control group. Levels of fibrinopeptide A were significantly lower in the heparin-coated circuit groups (P<0.05–0.01), irrespective of an aprotinin prime. D-dimer levels in the control group were significantly higher than in the other groups (P<0.05–0.01). The preservation rates of platelet count and function (acceleration of coagulation by platelet activating factor) in the control group were significantly lower than in the other three groups (P<0.05–0.01). Platelet preservation in the aprotinin plus heparin-coated group was significantly better than in the aprotinin only and the heparin-coated only groups (P<0.05). The amount of mediastinal drainage and the units of blood transfusion were significantly reduced in the two aprotinin groups, irrespective of heparin-coated use (P<0.01). The values in the aprotinin plus heparin-coated group were significantly less than the values in the heparin-coated only group (P<0.05). The heparin-coated circuit was beneficial for suppressing subclinical plasma coagulation and fibrinolysis and for preserving platelets. Addition of the minimal-dose aprotinin prime further preserved about a further reduction in postoperative blood loss and blood requirements.     

不同剂量肝素在体外循环心脏手术中应用的比较研究

目的观察两种不同剂量的肝素在体外循环心脏手术的一系列相关指标的差异,以评估低剂量肝素用于该手术的临床应用效果。方法将60例需要体外循环（CPB）心脏外科手术的患者随机分成两组,分别采用2mg／kg（n=30）和3mg／kg（n=30）的初始肝素剂量,比较两绀患行在术中和术后凝血功能、肝素化后活化凝血时间（ACT）、肝素总用量、鱼精蛋白量、微栓过滤网黏附度、_术中和术后输血量、血小板数量、术后24h胸引量以及手术并发症等相关指标。结果2mg／kg组（低利量组）中有1例患者肝素化ACT未达400S,3mg／kg组（常规组）中ACT全部达到400S以一L。两组患肯术中及术后均无心梗、脑梗及肺栓塞等血栓栓塞并发症发生,微栓过滤器黏附度、术后输血量、血小板数量、术后24h胸引量等指标均无统计学差异（P〉0．05）。相对于常规组,低剂量组的肝素化ACT较低（P〈0．05）,总肝素量、鱼精蛋白量和术中库血输入量明显减少（P〈0．05）。2组在血浆凝血酶原时间（PT,CPB20min和术后24h）、纤维蛋白原（Fib,CPB40rain和术后24h）指标上也存在差异（P〈0．05）。结论与常规剂量肝素相比,采用低剂量肝素同样能使多数患者肝素化ACT值大于400S,满足体外循环手术需求,减轻凝血功能紊乱,并减少术中输血量。     

Use of a soft reservoir bag in a fully heparin-coated closed-loop cardiopulmonary bypass system for distal aortic perfusion during aortic surgery

A fully heparin-coated closed-loop cardiopulmonary bypass system has recently been introduced into clinical practice. Without a venous reservoir, however, it does not allow control of the preload to the heart. We connected a soft reservoir bag in parallel with a centrifugal pump to enable preload control and clinically evaluated this modified system for distal aortic perfusion during aortic surgery. We have used the modified system in 17 patients since November 2002. For venous drainage, we use long narrow cannulae (21 ± 2 French). We administered 1 mg/kg heparin without cardiotomy suction and 2 mg/kg heparin with suction. We compared the clinical results with those in 13 patients who underwent distal aortic perfusion with an open cardiopulmonary bypass circuit between January 2002 and February 2004. We also analyzed factors affecting the coagulation system in these 30 patients using multiple regression analysis. With the modified system, venous drainage was adequate despite the use of smaller cannulae, and heparin reduction was not associated with thrombotic complication or elevated D-D dimer levels. Abrupt rises in proximal aortic pressure on aortic cross-clamping could be avoided by allowing blood to drain into the soft reservoir bag. Clinical results were not different from those with an open system. In the multiple regression analysis, the peak activated clotting time tended to correlate with postoperative platelet counts. This system is effective in controlling the preload to the heart and allows the safe reduction of heparin dosage. It therefore seems useful for distal aortic perfusion during aortic surgery.     

Blood transfusion requirements in coronary artery surgery with and without the activated clotting time (ACT) technique

Summary Control of anticoagulation during cardiopulmonary bypass (CPB) with the automated activated whole blood clotting time (ACT) and reversal of heparin after CPB using a computerized ACT dose-response curve method resulted in significant reductions of blood transfusion requirements, surgical time, and protamine doses in 150 patients undergoing coronary artery bypass grafting procedures (ACT group) as compared to 200 patients for whom a standard fixed dose protocol for heparin and protamine was used (control patients). Mean transfusion requirements were 1,938±60 SEM ml whole blood and 853±48.3 SEM ml red blood cells for control patients and 1,397±59 SEM ml whole blood (P<0.001) and 695±34 SEM ml red blood cells (P<0.01) in the ACT group. ACT group patients also required less protamine with 26.2±0.60 SEM ml Protamine 1,000 (Roche) as compared to 33.9±0.49 SEM ml for control patients (P<0.001) but more heparin with 31,440±783 SEM I.U. versus 26,760±263 SEM I.U. (P<0.001). Surgical time decreased from 321±5.5 SEM min for control patients to 289±5.4 SEM min for ACT group patients (P<0.001).Abbreviations AB autologous blood - ACD right coronary artery - ACT activated clotting time - ACT_o ACT — before heparin administration - ACT₃₆₀ ACT — 5 min. after 360 I.U. heparin/kg body wt. - CPB cardiopulmonary bypass - Cx circumflex branch of the left coronary artery - DIAG diagonal branch of the left coronary artery - ECC extracorporeal circulation - FB fresh blood - FFP fresh frozen plasma - POD postoperative day - RBC red blood cells - RIA descending branch of the left coronary artery - RIP posterior descending branch of the right coronary artery - WB whole blood     

Impact of non-di-(2-ethylhexyl)phthalate cardiopulmonary bypass tubes on inflammatory cytokines and coagulation-fibrinolysis systems during cardiopulmonary bypass

Di-(2-ethylhexyl)phthalate (DEHP), an excellent plasticizer for poly(vinyl chloride) (PVC), is a known endocrine-disrupting chemical. This study was designed to investigate whether a new non-DEHP bilayer tube reduced the release of DEHP, suppressed inflammatory cytokines, and altered coagulation-fibrinolysis systems. Sixteen patients undergoing coronary artery bypass grafting (CABG) were randomly assigned to the non-DEHP bilayer group (group B, n = 8), or the noncoated PVC group (group N, n = 8). The level of DEHP in the blood was measured before and after cardiopulmonary bypass (CPB). The levels of interleukin-6 (IL-6), D-dimer, and thrombin-antithrombin complex (TAT) were also measured at six points during and after CPB. DEHP was significantly lower in group B (472 ± 141 ng/ml) after CPB compared with group N (2094 ± 1046 ng/ml). The IL-6 level was significantly lower in group B (151 ± 131 pg/ml) than group N (206 ± 224 pg/ml) 180 min after protamine administration. The D-dimer level was significantly lower in group B 60 min after protamine administration (6.2 ± 2.4 μg/ml in group B vs 10.4 ± 4.5 μg/ml in group N) and 180 min after protamine administration (4.4 ± 0.7 μg/ml in group B vs 7.3 ± 2.7 μg/ml in group N). Group B had a tendency toward reduced postoperative bleeding compared with group N at any time. The bilayer tube was superior to the noncoated tube in terms of the inhibition of DEHP release, inflammatory cytokines, and the fibrinolysis system.     

Effect of myocardial protection on plasma histamine in the cardiotomy suction effluent during cardiopulmonary bypass in open heart surgery

Plasma histamine concentrations in samples obtained simultaneously from the extracorporeal circuit and the cardiotomy suction line were measured in two groups of patients undergoing cardiopulmonary bypass (CPB). In Group A patients, the technique for myocardial protection involved the use of intra-aortic instilled cardioplegic solution and extracorporeal cooling. Plasma histamine concentrations in the cardiotomy suction effluent (CSE) (median: 1.20 ng/ml; range: 0.31–8.42) were significantly higher than those in the extracorporeal circuit (ECC) (median: 0.53 ng/ml; range: 0.17–1.52) (p<0.02). In Group B patients, temperature drift and an intermittent cross-clamp fibrillation technique was employed. Plasma histamine concentrations in the CSE (median: 9.12 ng/ml; range: 1.88–15.46) and in the ECC (median: 9.66 ng/ml; range: 0.24–15.70) were comparable and directly related. Both groups of patients had histamine concentrations over 1 ng/ml in the CSE and contributed to the elevated circulatory histamine observed during CPB. This might contribute to possible haemodynamic consequences during the perioperative period.     

Clinical trial of argatroban, a direct thrombin inhibitor, as an anticoagulant in cardiopulmonary support and apheresis in emergency patients: a preliminary report

 To evaluate the safe and effective use of argatroban, a competitive direct thrombin inhibitor, as an alternative anticoagulant for percutaneous cardiopulmonary support (PCPS) and continuous hemofiltration or hemodiafiltration (CHF/CHDF), a preliminary multicenter clinical trial was conducted between October 1999 and September 2000. Nine patients who underwent PCPS and/or CHF/CHDF were enrolled in the study during this period. The dosage of argatroban was controlled so that the activated clotting time (ACT) was maintained at around 180 to 200 s. The mean duration of argatroban administration was 82 ± 92 h, and the mean dose was 0.67 ± 0.40 μg kg⁺¹ min⁻¹. Severe hemorrhagic complications requiring the discontinuation of argatroban administration were not observed in any of the patients. Platelet loss was prevented to some degree, and plasma levels of fibrinogen were well preserved during PCPS/CHDF. Except for two patients undergoing CHDF, clot formation within the extracorporeal circulation circuit was not identified macroscopically after the discontinuation of the procedures. We conclude that argatroban might be useful as an alternative anticoagulant in cases where heparin cannot be safely used because of the increased risk of bleeding complications, thrombocytopenia, and/or hypofibrinogenemia. Although the optimal dose of argatroban has not been established, we propose an initial starting dose of 0.7 to 1.0 μg kg⁻¹ min⁻¹, followed by adjustments to maintain an ACT of between 180 and 250 s. Received: December 17, 2001 / Accepted: June 1, 2002 Acknowledgments We thank Dr. S. Miyamoto (St. Marianna University School of Medicine), Dr. Y. Okada (Showa University School of Medicine), Dr. M. Shimizu, and Dr. J. Ishikawa (Yokohama City University School of Medicine) for providing data used in this study. We also thank Dr. S. Kanesaka (Showa University School of Medicine Fujigaoka Hospital) and Dr. S. Imaki (St. Marianna University School of Medicine, Yokohama City Seibu Hospital) for their helpful advice. Correspondence to:K. Akashi     

Use of argatroban as an alternative anticoagulant in cardiopulmonary support with an oxygenator: experimental study

 Argatroban, a selective and competitive antithrombin agent synthesized in Japan, was assessed for use as an alternative anticoagulant for partial venoarterial bypass with an oxygenator, by determining serial changes in hemostatic molecular markers. Fourteen dogs were divided into 3 groups in which partial veno-arterial bypass was carried out: a group in which no anticoagulant was used (group N, n = 3), a group in which 200 IU/kg of bolus heparin was used (group H, n = 5), and a group in which 10 μg/kg per min of intravenous argatroban was used (group A, n = 6). Both thrombin-antithrombin complex and fibrinopeptide A increased significantly in group N; they did not increase in group H. Group A showed high thrombin-antithrombin complex levels and significantly high fibrinopeptide A levels throughout the bypass procedure in comparison to levels in group H. However, plasma fibrinogen was maintained at higher levels in group A than in group H. Platelet count decreased significantly immediately after the start of bypass in groups N and H, but no significant change in platelet count was observed in group A. In conclusion, argatroban at a dose that prolongs activated clotting time to 200 s suppressed thrombin and fibrin generation less effectively than did full-dose heparin. However, excessive consumption of fibrinogen and accelerated fibrinolysis were not observed, and more platelets were preserved, suggesting that argatroban can be used safely in partial cardiopulmonary bypass with an oxygenator. Received: January 7, 2002 / Accepted: May 30, 2002 Correspondence to:M. Yokoyama     

Heparin coating of extracorporeal circuits inhibits cytokine release from mononuclear cells during cardiac operations

PURPOSE: To evaluate whether the production of interleukin 2 (IL 2), interleukin 6 (IL 6) and interleukin 10 (IL 10) from stimulated peripheral blood mononuclear cells (PBMC) was affected by coating extracorporeal circuits in patients undergoing cardiopulmonary bypass (CPB). In addition, postoperative clinical parameters were compared between patients with heparin-coated and uncoated CPB. DESIGN: Prospective, controlled in vivo/ex vivo study. PROCEDURE: Blood samples were drawn immediately before, at the end and 24 hours after the end of CPB using either a conventional circuit (n=10) or a heparin-coated circuit (n=10) in patients undergoing CPB. Cytokine release on the supernatants of activated PBMC was detected. Cardiopulmonary parameters were measured before CPB, at ICU admission, 3 hours and 24 hours after ICU admission in both groups of patients. Statistical difference intragroups and between groups were investigated with the analysis of variance for repeated measures. RESULTS: IL 6 and IL 10 release was significantly less (p<0.05) in the heparin-coated group. No differences in clinical parameters were observed between the two groups. CONCLUSIONS: These results suggest that with the use of heparin-coated circuits there is a lower production of IL 6 and IL 10 from isolated PBMC than with uncoated circuits.     

海藻酸钠交联肝素涂层在体外循环及人工心肺支持装置管路中的应用

背景：目前国内体外循环心脏手术使用的非肝素涂层管路和插管对血液破坏大、炎性反应重,影响心脏手术后患者的恢复和生存。 目的：采用生物医用高分子材料研制新型体外循环管道肝素涂层技术,并对其稳定性及抗凝血性能进行研究。 方法：利用CaCl₂将活化医用聚氯乙烯体外循环管道内表面修饰形成Ca2+膜,并与海藻酸钠和肝素交联;其中Ca²⁺与海藻酸钠、肝素钠中的Na+反应,从而使线型聚合物分子发生交联,形成化学交联海藻酸钠-肝素复合物的网状结构,实现生物型材料肝素化涂层。 结果与结论：CaCl₂修饰活化医用聚氯乙烯体外循环管道并与海藻酸钠和肝素交联反应,形成生物型高分子材料肝素化涂层管道,试验证明肝素化涂层管道具有良好的血液相容性、稳定性、抗凝血性能,可满足体外循环中短期转流的要求。     

Measurement of plasma fibrin D-dimer levels with the use of a monoclonal antibody coupled to latex beads

Recently, monoclonal antibody (DD-3B6) to fibrin D-dimer was prepared and coupled to latex beads to provide a specific test (Dimertest) for fibrinolysis. The purpose of this study was to evaluate the Dimertest assay as a clinical laboratory test for the measurement of plasma fibrin D-dimer derivatives. The Dimer-test assay specifically detected 2 micrograms/mL of purified fibrin D-dimer or fibrin D-dimer/fragment E complex added to afibrinogenemic plasma but did not detect 500 micrograms/mL of either fibrinogen fragments X, D, E, or 160 micrograms/mL cross-linked fibrinogen. The fibrin(ogen) degradation product (FDP) assays of American Dade or Wellcome Diagnostics detected 5.0 micrograms/mL of fibrin D-dimer and from 1 to 10 micrograms/mL of the other FDPs. Twenty-eight percent of 150 random plasma samples assayed from hospitalized patients were positive for fibrin D-dimer derivatives. Plasma samples from 152 patients suspected of having disseminated intravascular coagulation (DIC) were assayed for serum FDP (Wellcome Diagnostics) and plasma fibrin D-dimer derivatives. Samples from 69% of patients with serum FDP levels less than 10 micrograms/mL, and more than 90% of those with serum FDP levels greater than 10 micrograms/mL, were positive for fibrin D-dimer derivatives. Dimertest results were not modified by heparin, streptokinase, freeze-thawing, or clotting plasma. Serum fibrinogen-related antigens were immunoadsorbed from Dimer-test positive sera by anti-fibrinogen antibody and formalin-fixed Cowan I strain Staphylococcus aureus. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting with the use of monoclonal antibody DD-3B6 demonstrated a protein band with similar mobility to purified D-dimer. The measurement of plasma fibrin D-dimer derivatives by the Dimertest assay is a rapid, sensitive, and specific laboratory test for fibrinolysis. The Dimertest assay has proven to be a useful addition to the clinical laboratory and should be helpful in the diagnosis and management of patients with diseases associated with fibrinolysis.     

PMEA coating of pump circuit and oxygenator may attenuate the early systemic inflammatory response in cardiopulmonary bypass surgery

We investigated the effects of coating a cardiopulmonary bypass (CPB) circuit and oxygenator with poly-2-methoxy-ethyl acrylate (PMEA) on the systemic inflammatory response during and after CPB. Thirty patients undergoing elective cardiac surgery were randomized into three groups (each group n = 10): noncoated (group N), heparin coated (group H), and PMEA coated circuit and oxygenator (group X). Bradykinin (BK), complement 3 activation (C3a) and interleukin-6 (IL-6) levels were measured as early phase indicators of inflammatory response, as were maximum C reactive proteins (CRP) and white blood cell (WBC) levels. The alveolar-arterial oxygen gradient (A-a DO2) was measured as a parameter of respiratory function. IL-6 levels after CPB were significantly higher in group N than in groups H and X (p < 0.05). Serum BK and C3a levels showed similar patterns in all groups. A-a DO2 was lower at the end of and 3 hours after CPB in groups H and X than in group N (p < 0.05). Maximum CRP levels were lower in group X than in groups N (p < 0.05). This prospective study suggests that PMEA coated CPB may improve respiratory function and decrease systemic inflammatory response after cardiac surgery, possibly because this circuit is as biocompatible as heparin coated CPB circuit.     

The impact of heparin coated circuits upon metabolism in vital organs: effect upon cerebral and renal function during and after cardiopulmonary bypass

During cardiopulmonary bypass (CPB), the brain and the kidneys may be damaged because of microemboli, ischemia, and inflammation. The latter has been reduced by the use of heparin coated circuits. We questioned whether heparin coated circuits could also reduce cerebral and renal damage and whether inflammatory markers correlate with damage to the brain and the kidneys. Fifty-one patients scheduled for coronary artery bypass grafting were perfused with either a heparin coated or an uncoated circuit. To compare the effect of a heparin coated circuit with an uncoated circuit upon cerebral and renal function in relation to inflammation, we assessed markers of cerebral (S100beta) and renal (N-acetyl-beta-D-glucosaminidase [NAG], creatinine, and urea) function, inflammation, and oxygen metabolism. S100beta levels and NAG levels increased during CPB in both groups as compared with baseline levels (p < 0.01), without differences between the groups. After 15 minutes on CPB, C4b/c levels were significantly higher in the coated group compared with the uncoated group (p < 0.02). C4b/c correlated with S100beta (p < 0.01). Total body oxygen delivery (DO2) and consumption (VO2) decreased significantly in both groups during CPB (p < 0.01), but recovery was better in the coated group. After protamine infusion, total body oxygen delivery and consumption correlated negatively with S100beta levels (both p < 0.05) and with NAG levels (both p < 0.01). This study suggests that, if adequate tissue perfusion is not maintained, the use of a heparin coated circuit gives no additional benefit beyond that of the uncoated circuit. The inverse relationship of both cerebral and renal markers with DO2 and VO2 suggests that increased levels of S100beta and NAG during CPB may primarily be caused by an oxygen deficit and secondary to the inflammatory response.     

Clinical study of biocompatibility between open and closed heparin-coated cardiopulmonary bypass circuits

The objective of this study was to investigate the difference between the closed circuit system and the open circuit system in clinical heparin-coated cardiopulmonary bypass (CPB) circuits with a centrifugal pump. We evaluated the coagulation, fibrinolysis, and inflammatory response in valvular heart surgery. Nineteen patients were assigned at random to a group for the closed circuit system or the open circuit system. This is the first report on the effect of a closed circuit in valvular surgery. We measured the platelet count, white blood cell count, plasma fibrinogen concentration, thrombin–antithrombin III complex, plasmin-2 plasmin inhibitor complex, D-dimer, interleukin-6, polymorphic neutrophil-elastase, and the plasma free hemoglobin. Blood samples were collected before the start of perfusion, 15 and 60min after the start of perfusion, 60min after the administration of protamine, and 1 day after the operation. During the perfusion, coagulation, fibrinolysis, and inflammatory responses were activated; however, no significant differences between the two groups were noted. In this clinical investigation with suction and the cell saving system, the closed circuit was not found to be superior to the open circuit with regard to biocompatibility.     

Effect of heparin reversal and fresh platelet transfusion on platelet emboli post-cardiopulmonary bypass in a pig model

Heparin reversal by protamine and fresh platelet transfusion may decrease bleeding complications post-cardiopulmonary bypass (CPB) and may increase the level of organ trapped platelet emboli. Platelet emboli were quantified in two groups of 12 Yorkshire pigs (30-35 kg), where 111indium labeled autologous platelets (INPLT: 850-1,200 microCi) were injected intravenously before and after CPB (BCPB, ACPB), and the platelet emboli level in intact organs and their samples (brain, heart, kidneys, lung, liver, and spleen) was quantified with an ion chamber and a gamma counter, respectively. All pigs were systemically heparinized (ACT > 400 sec). CPB was carried out at 2.5-3.5 L/min at 28 degrees C using a centrifugal pump, an oxygenator (OX:Bentley Univox 1.8 m2), an arterial filter (AF:0.25 m2), and a cardiotomy reservoir (CR: BMR 250) for 90 min. Heparin was reversed with an equivalent dose of protamine. The percent of INPLT dose (ID%, mean +/- SD) in organs of BCPB and ACPB pigs was calculated. The sequence of platelet emboli on a unit weight basis (ID%/g) had the following order: Spleen > Liver > Lung > Kidneys > Heart > Brain. The presence of significantly higher levels of emboli in brain, heart, and kidneys in the ACPB than the BCPB group suggest that platelet transfusion after heparin reversal with protamine may increase the risk of platelet emboli. However, it is an acceptable risk for patients having bleeding complications post-CPB.     

Poly-2-methoxyethylacrylate-coated cardiopulmonary bypass circuit can reduce transfusion of platelet products compared to heparin-coated circuit during aortic arch surgery

Several coating techniques for extracorporeal circulation have been developed to reduce the systemic inflammatory response during cardiopulmonary bypass (CPB). We compared the clinical effectiveness and biocompatibility of poly-2-methoxyethylacrylate (PMEA)- and heparin-coated CPB circuits in total aortic arch replacement (TAR) with the prolonged use of the bypass technique. Twenty patients who underwent elective TAR were divided randomly into two equal groups: group P (n = 10) to use PMEA-coated circuits and group H (n = 10) to use heparin-coated circuits. Clinical outcomes, hematological variables, and acute phase inflammatory response were analyzed perioperatively. Demographic, CPB, and clinical outcome data were similar for both groups. Hemoglobin and platelet count showed similar time-course curves. However, the amount of platelet products transfused intraoperatively was significantly larger in group H (group P 26.0 ± 7.0 units; group H 33.0 ± 6.7 units, p = 0.04). Total protein, and albumin levels were significantly higher in group P during and after the operation (total protein, p = 0.04; albumin, p = 0.02). The use of PMEA-coated circuit is associated with retainment of perioperative plasma proteins levels and may help to reduce transfusion of platelet products in TAR in comparison with the heparin-coated circuit.     

Clinical usefulness of the measurement of plasma D-dimer levels

To evaluate the clinical usefulness of D-dimer, various effects on the measurement of D-dimer were examined. Although both fibrinolytic and fibrinogenolytic products were detected by the measurement of FDP, only fibrinolytic products were detected by the measurement of D-dimer. In patients with DIC and other thrombo-embolic diseases, plasma D-dimer levels were significantly higher than in normal persons. A significant positive correlation between plasma D-dimer and serum FDP was found in DIC patients. In patients with DIC associated with acute promyelocytic leukemia, which is thought to be an increased fibrinogenolysis state, serum FDP was higher than the plasma D-dimer which suggests that increased fibrinogenolysis affects the result of serum FDP measurement. Plasma D-dimer significantly increased 5 minutes after endoscopic embolization with thrombin in the patients with esophageal varices. However serum FDP increased 30 minutes after the treatment, which suggests that the D-dimer is more useful for rapid detection of coagulo-fibrinolytic change than serum FDP. Plasma D-dimer was significantly higher in patients with cerebral infarction and increased with age. These finding suggest the usefulness of plasma D-dimer measurement for the specific and rapid evaluation of coagulo-fibrinolytic activation and thrombo-embolic state.     

Changes in platelet aggregation during cardiopulmonary bypass: comparison of poly-2-methoxyethylacrylate and heparin as a circuit coating material

At present, there are various biomaterials that have high biocompatibility. In particular, there are many types of coated circuits in cardiopulmonary bypass (CPB) systems. However, only a few clinical studies have investigated platelet aggregation caused by these coated circuits. In this study, a CPB system coated with poly-2-methoxyethylacrylate (X coating) was used to ascertain whether platelet aggregation could be suppressed during CPB, and a comparison was made between X coating and ordinary (covalently bonded) heparin coating. The subjects were 19 adult patients who were scheduled to undergo valve replacement or valvuloplasty. They were divided into two groups: group X (X coating) and group H (heparin coating). The platelet aggregation threshold index (PATI, grading curve) and β-thromboglobulin and plalelet factor IV levels were assessed preoperatively (control), 5 min after heparin administration, 10 and 60 min after the start of CPB, and 0 and 2 h after the end of CPB. The results indicated that platelet aggregation was reduced during CPB and that platelets were activated. The changes in platelet aggregation associated with the X coating were shown to be similar to those associated with heparin coating.     

下肢骨折围手术期凝血-抗凝及纤溶指标动态变化的意义

目的：探讨下肢骨折患者围手术期凝血一抗凝及纤溶指标动态变化规律,指导临床有针对性预防下肢深静脉血栓形成。方法：选择下肢骨折需卧床治疗患者35例为实验组,选择上肢骨折患者30例为对照组。分别于术前、术后1d、术后3d及术后14d采集静脉血,检测血浆凝血酶原时间（PT）、活化部分凝血活酶时间（AFIT）、纤维蛋白原（FIB）、纤维蛋白（原）降解产物（FDP）、D．二聚体（D-D）、抗凝血酶活性（AT）。结果：FIB、FDP和D-D：实验组术后1d和术后14d与术前比较差异有非常显著性意义（P〈0．01）,对照组术后1d与术前比较差异有非常显著性意义（P〈0．01）;AT：实验组术后14d与术前比较差异有非常显著性意义（P〈0．01）。结论：下肢骨折患者术后局部血流减慢,FIB、FDP和D-D增高,AT降低,提示机体可能处于血栓前状态或有血栓形成。