Systemic hemostatic medications for reducing surgical blood loss

OBJECTIVE: To review randomized trials involving the use of systemic hemostatic medications for reducing surgical blood loss. DATA SOURCES: Articles were obtained through searches of MEDLINE (1966-September 2000). The bibliographies of retrieved publications were reviewed for additional references. STUDY SELECTION: All randomized studies and pharmacoeconomic evaluations that involved medications used for systemic hemostasis in the perioperative period were included. DATA EXTRACTION: Randomized studies involving conjugated estrogens, aminocaproic acid, tranexamic acid, desmopressin, and aprotinin for systemic hemostasis were extracted. Studies of proton-pump inhibitors for upper gastrointestinal bleeding and octreotide for variceal bleeding were excluded, as were trials involving the use of any hemostatic agent for cardiovascular surgery. The primary outcome under review was a reduction in bleeding as defined by reduced transfusion requirements. DATA SYNTHESIS: There is limited efficacy and toxicity information concerning the use of conjugated estrogens for reducing surgery-related bleeding. Similarly, there are a limited number of randomized studies involving aminocaproic acid and tranexamic acid, and with the exception of tranexamic acid for reducing transfusion requirements with knee surgery, the study results are either conflicting or negative. For desmopressin, evidence from a substantial number of randomized trials documents its lack of efficacy. Aprotinin has reduced bleeding and transfusion requirements in a number of randomized studies involving patients undergoing orthopedic surgery, but cost-effectiveness studies are needed to better define its therapeutic role. Trials of aprotinin during hepatic surgery have yielded conflicting results. CONCLUSIONS: Most hemostatic medications used for reducing surgery-related bleeding have limited or contradictory evidence of efficacy.     

A Review of Post--Cardiopulmonary Bypass Bleeding, Aminocaproic Acid, Tranexamic Acid, and Aprotinin

OBJECTIVE: To review the mechanism and cause of hemostatic defects following cardiopulmonary bypass (CPB) and determine the safety and efficacy of antifibrinolytic agents for use in cardiac surgery and patients likely to benefit. DATA SOURCES: A MEDLINE search (1966 to present) of the English-language literature pertaining to aminocaproic acid (ACA), tranexamic acid (TA), and aprotinin was performed. Additional literature was obtained from reference citations of pertinent articles identified through the search. STUDY SELECTION AND DATA EXTRACTION: While all articles of relevance were considered for inclusion, this review evaluates only clinical trials with emphasis on prospective, randomized, controlled studies. DATA SYNTHESIS: In reported trials, ACA and TA each reduce mediastinal blood losses by about one-third, while transfusion needs remain unchanged. ACA and TA dosing inconsistencies, omission of transfusion criteria, and unidentified surgical risk factors prevent optimal findings. Thromboembolic complications could not be ascribed to either ACA or TA in more than 950 patients studied. Aprotinin decreased mean mediastinal blood losses by 42%, 67% and 48% in primary coronary artery bypass grafting (CABG), reoperative CABG, and in CABG patients receiving aspirin, respectively. Transfusion needs were reduced 42% in primary CABG patients and 55% to 88% in high-risk patients. Patients at high risk of bleeding (i.e., reoperative CABG and patients on aspirin) demonstrated greater transfusion needs and blood loss than primary CABG patients. As blood conservation measures may eliminate the need for transfusions among primary CABG patients, patients at higher risk may benefit most from the addition of antifibrinolytic prophylaxis. CONCLUSION: The efficacy of all antifibrinolytic agents in cardiac surgery has been established, but comparative data is inconclusive to suggest an agent of choice. Thromboembolic complications have been rare and difficult to ascribe to antifibrinolytic agents. Future trials comparing efficacy of agents in high risk patients and rigorously evaluating thromboembolic events will allow unconditional recommendations.     

Proton-pump inhibitors for acute peptic ulcer bleeding

OBJECTIVE: To review the use of proton-pump inhibitors for acute peptic ulcer bleeding. DATA SOURCES: Articles were obtained through computerized searches of MEDLINE (1966-September 2000). Additionally, several textbooks containing information on the diagnosis and management of acute peptic ulcer bleeding were reviewed. The bibliographies of retrieved publications and textbooks were reviewed for additional references. STUDY SELECTION: All randomized studies and pharmacoeconomic evaluations that used proton-pump inhibitor therapy for acute peptic ulcer bleeding were included. Randomized controlled trials and meta-analyses involving other therapies for treating peptic ulcer bleeding were also reviewed for possible inclusion. DATA EXTRACTION: The primary outcomes extracted from the literature were persistent or recurrent bleeding, transfusion requirements, need for endoscopic intervention or surgery, length of stay, and mortality. DATA SYNTHESIS: Data from double-blind, placebo-controlled trials involving more than 1000 patients demonstrate that short-term, high-dose omeprazole therapy is effective for reducing bleeding and transfusion requirements in patients with acute peptic ulcer bleeding. The patients most likely to benefit from this therapy are hospitalized patients at high risk for rebleeding and patients in whom endoscopic evaluation must be delayed or is unavailable. CONCLUSIONS: Omeprazole (and likely other proton-pump inhibitors) is useful in reducing bleeding and transfusion requirements in patients with acute peptic ulcer bleeding, although better delineation of appropriate candidates is needed.     

Effects of cardiac surgery on hemostasis

Cardiac surgery affects both coagulation and platelet function. Revision of surgery due to bleeding has to be performed in 2% to 6% of patients undergoing cardiac surgery and is generally associated with a marked deterioration in prognosis. Factors contributing to acquired hemostatic abnormalities in cardiac surgery include the use of anticoagulants as well as the activation and consumption of coagulation factors and platelets induced by the extracorporeal circulation. Prophylactic use of antifibrinolytic agents such as aprotinin and tranexamic acid has been demonstrated to reduce the blood loss by half. Adequacy of heparin-induced anticoagulation in the perioperative setting is commonly controlled by the activated clotting time. This method also indicates the correct reversal of the heparin effect by protamine. In recent years, thrombelastography has proved to be valuable for diagnosis of coagulopathy associated with cardiac surgery. In addition, the use of thrombelastography-based algorithms has been shown to reduce transfusion requirements. In contrast to point of care methods, laboratory assessment of hemostasis is more time-consuming and, thus, often not as rapidly available as required. At this time, the therapy for perioperative hemostatic abnormalities is based mainly on the administration of blood components (fresh frozen plasma and platelet concentrates). In the future, recombinant activated factor VIIa might prove to be a therapeutic option in patients with otherwise untractable bleeding, but the efficacy of recombinant activated factor VIIa has yet to be defined for this indication.     

A propensity score case-control comparison of aprotinin and tranexamic acid in high-transfusion-risk cardiac surgery

BACKGROUND: Cardiac surgery with cardiopulmonary bypass may result in excessive fibrinolysis and platelet (PLT) dysfunction, resulting in impaired hemostasis and excessive blood loss. Prophylactic use of the antifibrinolytic drugs aprotinin and tranexamic acid is thought to prevent these hemostatic defects. Their relative clinical utility and safety in high-transfusion-risk cardiac surgery, however, is not known. STUDY DESIGN AND METHODS: Using propensity scores, 449 patients who received aprotinin for high-transfusion-risk cardiac surgery were matched to 449 patients who received tranexamic acid from a pool of 10,870 consecutive patients who underwent cardiac surgery at a single center, 586 of whom received aprotinin and the remainder of whom received tranexamic acid. RESULTS: The two matched groups were well balanced in terms of measured perioperative variables. Blood product transfusion rates were similar in the aprotinin and tranexamic acid groups: red blood cells, 79 percent versus 76 percent (p = 0.3); PLTs, 56 percent versus 50 percent (p = 0.06); and plasma, 66 percent versus 61 percent (p = 0.1). Adverse events rates were comparable in the two groups, except for renal dysfunction (defined as a greater than 50% increase in creatinine concentration during the first postoperative week to >100 micromol/L in women and >110 micromol/L in men or a new requirement for dialysis support), which occurred in 24 percent (107/449) of aprotinin patients and 17 percent (75/449) of tranexamic acid patients (p = 0.01). CONCLUSIONS: Aprotinin and tranexamic acid have similar hemostatic effectiveness in high-transfusion-risk cardiac surgery. Within the confines of propensity score matching, our results suggest that aprotinin may be associated with renal dysfunction.     

Octreotide for acute variceal bleeding

OBJECTIVE: To review the use o f octreotide for acute variceal bleeding. DATA SOURCES: Articles were obtained through computerized searches involving MEDLINE (from 1997 to October 2000). Additionally, several textbooks containing information on the diagnosis and management of acute variceal bleeding were reviewed. The bibliographies of retrieved publications and textbooks were reviewed for additional references. STUDY SELECTION: All randomized studies and pharmacoeconomic evaluations that used octreotide therapy for acute variceal bleeding were considered. Randomized controlled trials and meta-analyses involving other therapies for treating variceal bleeding were also reviewed for possible inclusion. DATA EXTRACTION: The primary outcomes extracted from the literature were persistent or recurrent bleeding, need for endoscopic intervention or balloon tamponade, and mortality. DATA SYNTHESIS: Although both endoscopic therapies and medications are used to control bleeding and rebleeding episodes, the endoscopic approach has the additional goal of obliterating the varix. Since rebleeding episodes are common as long as the varix is present, endoscopic and medication therapies cannot be considered interchangeable based on bleeding control alone. However, octreotide by continuous intravenous infusion has demonstrated effectiveness in reducing blood loss and transfusion requirements as both an initial intervention (until definitive sclerotherapy can be performed) or as adjunctive therapy to endoscopic measures. Octreotide can be started quickly, has a relatively rapid onset of action, and does not require someone with endoscopy training to initiate. Additionally, octreotide is relatively free of significant adverse effects. CONCLUSIONS: While additional investigations are needed, particularly in the area of pharmacoeconomics, there is substantial evidence that octreotide is an efficacious therapy with relatively few adverse effects when used in the management of acute variceal bleeding.     

Blood transfusion support in pediatric cardiovascular surgery

The majority of children who undergo open-heart surgery with cardiopulmonary bypass (CPB) require perioperative blood transfusion. Blood product requirements are affected by factors such as patient age, underlying cardiac disease, complexity of the surgical procedure, and hemostatic alterations induced by CPB. Transfusion support may include the use of whole blood and/or individual blood components with transfusion practices varying widely based on individual preferences and blood product availability. Approaches to limit allogeneic blood exposure include the use of modified ultrafiltration and smaller bypass circuits, preoperative autologous blood donation and intraoperative blood salvage, and adjunctive antifibrinolytic agents. Potential advantages and disadvantages of the different blood products and pharmacological agents must be considered in managing the pediatric cardiac surgery patient.     

Hemostatic Resuscitation in Children

Trauma is a major source of morbidity and mortality for children worldwide; life-threatening hemorrhage is a primary cause of preventable death. Essential interventions in children with life-threatening hemorrhage include hemostatic resuscitation and mechanical control of bleeding. Herein we review pediatric hemostatic resuscitation, a strategy that addresses both hemorrhagic shock and the coagulopathic complications described in patients with major hemorrhage. Some components of hemostatic resuscitation may include: early and aggressive resuscitation with blood products, minimizing crystalloid and hemodilution, antifibrinolytic adjuncts such as tranexamic acid, and the novel use of low-titer group O whole-blood (LTOWB) transfusion in injured children. The following selection of important publications address the current state of hemostatic resuscitation strategies in pediatric trauma patients as well as the remaining knowledge gaps and areas for further research.     

氨甲环酸减少脊柱矫形术围术期出血的临床观察

目的观察抗纤溶药物氨甲环酸在减少脊柱矫形术围术期出血的疗效与安全性。方法收集2008年1月至2011年10月接受脊柱矫形手术92例随机分成两组,治疗组41例手术开始前15 min给于氨甲环酸1 g负荷量缓慢静脉注射10 min,手术开始后持续给以10 mg/(kg.h)的氨甲环酸维持量TXA[10 mg/(kg.h)]至手术结束。对照组51例给予相应生理盐水;比较两组患者术中、术后24 h失血量、输血量并观察出凝血功能及药物副反应。结果①与照组相比,治疗组术中失血量、输血量、术后24 h引流量均显著减少;②两组凝血酶原时间(PT)、凝血活酶时间(APTT)、国际标准化比值(INR)、纤维蛋白原(FIB)差异无统计学意义(P>0.05)。术后无深静脉血栓、肾功能衰竭、心肌梗死、脑梗塞、伤口感染等并发症的发生。结论静脉应用氨甲环酸抗纤溶治疗对脊柱矫形术围术期止血安全有效。     

Comparison of the effects of aprotinin and tranexamic acid on blood loss and red blood cell transfusion requirements during the late stages of liver transplantation

BACKGROUND: During liver transplantation (LT), profound activation of the fibrinolytic system can contribute significantly to perioperative bleeding. Prophylactic administration of antifibrinolytic agents has been shown to reduce blood loss and the need for allogeneic transfusion in these conditions. STUDY DESIGN AND METHODS: This prospective randomized trial included 51 cirrhotic patients undergoing LT. Patients were randomly assigned to receive either 280 mg of aprotinin (AP) followed by 70 mg per hour or 40 mg per kg tranexamic acid (TA) followed by 40 mg per kg per hour, administered from the end of the anhepatic phase until 2 hours after reperfusion of the graft, and the effects on blood loss and red blood cell (RBC) transfusion requirements were compared. Transfusion policy was standardized in all patients. In addition, the biological effects of the two drugs, as assessed by coagulation and fibrinolytic markers obtained during surgery, were evaluated in a subgroup of patients from each treatment group and compared with an historical control group that did not receive antifibrinolytic drugs. RESULTS: There was no significant difference between the two groups in perioperative blood losses (AP, 6200 [4620-8735] mL; TA, 5945 [4495-8527] mL; median [range]) or in RBC transfusions requirements (AP, 9 [6.75-15.25] units; TA, 10 [6.5-13.5] units). Inhibition of fibrinolysis was observed with both drugs compared with the control group. Coagulation appeared to be activated more with AP, however, whereas fibrinolysis was inhibited more by TA. CONCLUSION: Blood losses and RBC transfusion requirements were comparable regardless of the drug administered. TA may be as valuable as AP for controlling fibrinolysis in LT.     

Mortality associated with administration of high-dose tranexamic acid and aprotinin in primary open-heart procedures: a retrospective analysis

Introduction  

Antifibrinolytic agents are commonly used during cardiac surgery to minimize bleeding. Because of safety concerns, aprotinin was withdrawn from the market in 2007. Since then, tranexamic acid (TXA) has become the antifibrinolytic treatment of choice in many heart centers. The safety profile of TXA has not been extensively studied. Therefore, the aim of this study was to evaluate safety and efficiency of TXA compared with aprotinin in cardiac surgery.     

Over-the-counter medications in cardiac transplant recipients: guidelines for use.

OBJECTIVE: The purpose of this article is to review the pathophysiology of the denervated heart and the factors that need to be considered before recommending the use of over-the-counter (OTC) medications in the cardiac transplant recipient. DATA SOURCES: Pharmacology and therapeutic textbooks, English-language journal articles, and physiology textbooks published between 1969 and 1991. DATA EXTRACTION: Case reports, controlled case studies, and textbook chapters evaluating drug interactions with immunosuppressive agents were reviewed. The effects of various OTC medications on the denervated heart were examined and relevant material was extrapolated. DATA ANALYSIS: The number of cases or studies in which a particular effect or interaction occurred was reported. Those findings that were less well documented were either identified as such or were not included in the review. DATA SYNTHESIS: Common pharmacokinetic and pharmacodynamic interactions with the primary immunosuppressive agents (e.g., cyclosporine, azathioprine, prednisone) are reviewed. The physiology and altered responses of the denervated heart to various medications are also explained. Using this information recommendations are given for the use and monitoring of OTC analgesics, antacids, laxatives, sleep aids, stimulants, and other medications that may be used in the cardiac transplant recipient. CONCLUSIONS: Many OTC medications can be used safely in the cardiac transplant recipient. In each situation, risk/benefit assessments must always be made and therapy should be monitored closely. Most important, patients should always notify the transplant team before adding an OTC product to their immunosuppressive regimen.     

Epsilon aminocaproic acid is associated with acute kidney injury after life-threatening hemorrhage in children

Background

Antifibrinolytic medications have been associated with reduced mortality in pediatric hemorrhage but may contribute to adverse events such as acute kidney injury (AKI).

Study Design and Methods

We conducted a secondary analysis of the MAssive Transfusion in Children (MATIC), a prospectively collected database of children with life-threatening hemorrhage (LTH), and evaluated for risk of adverse events with either antifibrinolytic treatment, epsilon aminocaproic acid (EACA) or tranexamic acid (TXA). The primary outcome was AKI and secondary outcomes were acute respiratory distress syndrome (ARDS) and sepsis.

Results

Of 448 children included, median (interquartile range) age was 7 (2–15) years, 55% were male, and LTH etiology was 46% trauma, 34% operative, and 20% medical. Three hundred and ninety-three patients did not receive an antifibrinolytic (88%); 37 (8%) received TXA and 18 (4%) received EACA. Sixty-seven (17.1%) patients in the no antifibrinolytic group developed AKI, 6 (16.2%) patients in the TXA group, and 9 (50%) patients in the EACA group (p = .002). After adjusting for cardiothoracic surgery, cyanotic heart disease, preexisting renal disease, lowest hemoglobin pre-LTH, and total weight-adjusted transfusion volume during the LTH, the EACA group had increased risk of AKI (adjusted odds ratio 3.3 [95% CI: 1.0–10.3]) compared to no antifibrinolytic. TXA was not associated with AKI. Neither antifibrinolytic treatment was associated with ARDS or sepsis.

Conclusion

Administration of EACA during LTH may increase the risk of AKI. Additional studies are needed to compare the risk of AKI between EACA and TXA in pediatric patients.     

Lack of efficacy of tranexamic acid in thrombocytopenic bleeding

A controlled, randomized, double-blind study was performed to assess the effect of the oral antifibrinolytic agent tranexamic acid in patients with amegakaryocytic thrombocytopenia as regards their need for platelet transfusions and the number of bleeding episodes experienced. Each patient served as his or her own control and received sequential, randomized courses of either tranexamic acid or an identical placebo. The need for platelet transfusions due to bleeding and the total number of bleeding episodes were compared for tranexamic acid and placebo courses. Patients received platelet transfusions at the discretion of their personal physician and kept detailed records of bleeding episodes. Of three patients who completed the full study, none had a reduction in the need for platelet transfusions. Moreover, in the eight patients who participated in the study, there was no reduction in number of bleeding episodes during tranexamic acid treatment as compared to the number with placebo. Our data indicate that the prophylactic administration of tranexamic acid does not decrease dependence on platelet transfusions or decrease bleeding episodes in patients with bleeding due to amegakaryocytic thrombocytopenia.     

Tranexamic acid for gastrointestinal bleeding: A systematic review with meta-analysis of randomized clinical trials

BackgroundAcute gastrointestinal bleeding is a common life-threatening emergent condition. Immediate tranexamic acid is useful for reducing hemorrhage following operation and bleeding trauma, but evidence on the effects of tranexamic acid in patients with gastrointestinal bleeding is limited or highly heterogeneous. It is still unclear about using tranexamic acid in the emergent condition of gastrointestinal bleeding. This study, therefore, aimed to determine whether or not tranexamic acid should be used in gastrointestinal bleeding management through systematic review and meta-analysis.MethodsWe searched three biomedical databases for relevant randomized controlled trials on this topic. Two authors independently selected studies and extracted data for bias assessment and meta-analysis of bleeding, further intervention, mortality, transfusion, and intensive care unit admission. Available data were pooled using a random-effects model, and the results were presented as risk ratios (RRs) with 95% confidence intervals (CIs). Heterogeneity and small study effects were also assessed.ResultsThirteen randomized controlled trials (n = 2271) were included in the present synthesis. Our meta-analysis revealed that tranexamic acid significantly reduced the rates of continued bleeding (RR = 0.60; 95%CI, 0.43–0.84), urgent endoscopic intervention (RR = 0.35; 95%CI, 0.24–0.50), and mortality (RR = 0.60; 95%CI, 0.45–0.80) compared with the placebo.ConclusionAccording to the available evidence, the present synthesis confirms that tranexamic acid is an effective medication for patients with upper gastrointestinal bleeding. Early administration of tranexamic acid may be worth to be recommended for treating upper gastrointestinal bleeding in the emergency department. However, the effects of tranexamic acid on lower gastrointestinal bleeding warrant further clarification.     

氨甲环酸与体外循环下心脏手术患者出血的相关性

目的研究和分析氨甲环酸与体外循环下心脏手术病人出血的相关性。方法选取185例体外循环心脏手术患者作为研究对象,根据患者术中是否应用氨甲环酸将患者分为观察组81例(术中应用氨甲环酸)和对照组104例(术中未应用氨甲环酸)。对2组患者术前和术后24h的红细胞压积(HCT)、血小板计数(PLT)、凝血酶原时间(PT)、活化部分凝血酶原时间(APTT)、纤维蛋白原(FIB)等血常规及凝血功能指标水平进行检测和比较。对2组患者的体外循环时间、主动脉阻断时间、术中肝素应用量、术中鱼精蛋白应用量进行记录和比较。对2组患者术中和术后24 h出血量、输注浓缩红细胞量、输注血浆量、输注血小板量、因出血行二次开胸手术发生率进行观察和比较。对2组患者术后急性肾功能衰竭、肾功能不全、神经系统并发症、低心排综合征、二次插管、肺部感染的发生率及住院死亡率进行观察和比较。结果 2组患者术后24 h的HCT水平、PLT水平、FIB水平均较治疗前显著下降(P0.05),对照组患者术后24 h的PLT水平显著低于观察组(P0.05)。对照组患者的术中和术后出血量、各项输血量及因出血行二次开胸手术发生率均显著高于观察组(P0.05)。2组患者的各项手术相关指标的差异均无统计学意义(P0.05)。2组患者术后各项并发症发生率及住院死亡率的差异均无统计学意义(P0.05)。结论在体外循环心脏手术中应用氨甲环酸可有效减少患者的术中、术后出血量和输血量,保护患者的凝血功能。     

氨甲环酸在婴儿先心手术中的应用

目的：观察和评价在小婴儿先心手术中应用抗纤溶药物氨甲环酸的疗效和安全性。方法：80例1岁以内的先天性房缺或室缺患儿。随机分为两组,氨甲环酸组（组Ⅰ,n=40）,氨甲环酸90mg·kg^-1,分3次给予,每次30mg·kg^-1,依次为术前、预充液中、体外循环后。安慰荆组（组Ⅱ,n=40）给予0．9％氯化钠液9mg·kg^-1,给药方式同组Ⅰ观察项目：手术前后血细胞压积、血小板计数、常规凝血功能、D-二聚体数值;术后24h胸腔引流量、输血量、心血管重症监护室停留时间、肾功能指标、血栓形成和过敏反应。结果：氨甲环酸组术后24h出血量为（9．0±4．8）mL·kg,安慰剂组为（11．9±9．3）mL·kg^-1（P〈0．05）,术后24h出血量减少24％;两组术后输血量无差别;两组术后及24hD-二聚体值均明显增加,氨甲环酸组增加程度明显小于安慰剂组（P〈0．05）;两组术后凝血功能指标治化部分凝血酶时间（APTT）显著延长,凝血酶原活动度（PTA）显著下降,血小板数量明显降低,组内差异显著,组间无显著差异,常规凝血指标术后24h基本恢复。术后无肾功能不全及血栓形成、过敏反应。结论：婴儿先天性房缺或室缺手术中90mg·kg^-1氨甲环酸能使术后出血量减少24％。     

Acute Management of Hemostasis in Patients With Neurological Injury

Neurological injuries can be divided into those with traumatic and nontraumatic causes. The largest groups are traumatic brain injury (TBI) and nontraumatic stroke. TBI patients may present with intracranial hemorrhages (contusions, or subdural or epidural hematomas). Strokes are ischemic or hemorrhagic. In all these disorders, thrombosis and hemostasis play a major role. Treatment aims to either cease bleeding and/or restore perfusion. We reviewed hemostatic and thrombolytic therapies in patients with neurological injuries by MEDLINE and EMBASE search using various key words for neurological disorders and hemostatic therapies restricted to English language and human adults. Review of articles fulfilling inclusion criteria and relevant references revealed that, in patients with ischemic stroke, intravenous thrombolytic therapy with recombinant tissue plasminogen activator within 4.5-5 hours after onset of symptoms improves clinical outcome. In contrast, there are no hemostatic therapies that are proven to improve clinical outcome of patients with hemorrhagic stroke or TBI. In patients with hemorrhagic stroke who use vitamin K antagonist or direct oral anticoagulants, there is evidence that specific reversal therapies improve hemostatic laboratory parameters but without an effect on clinical recovery. In patients with hemorrhagic stroke or TBI who use concomitant antiplatelet therapy, there is evidence for harm of platelet transfusion. In patients with aneurysmal subarachnoid hemorrhage, tranexamic acid was shown to reduce rebleeding rate without improving clinical outcome. The effects of tranexamic acid in patients with TBI are still under investigation. We conclude that, in patients with ischemic stroke, thrombolytic therapy improves outcome when given within 4.5-5 hours. In hemorrhagic stroke and TBI, most hemostatic therapies improved or corrected laboratory parameters but not clinical outcome. Currently, in several trials, the effects of tranexamic acid are being studied of which the results are eagerly awaited. Because improving clinical outcome should be the goal of new therapies, we encourage to use clinical outcome scales as the primary outcome measure in trials that investigate effects of hemostatic therapies in patients with neurological injury.     

Prediction and management of bleeding in cardiac surgery

Summary.  Excessive bleeding after cardiac surgery can result in increased morbidity and mortality related to transfusion- and hypoperfusion-related injuries to critical organ systems.
Our objective was to review mechanisms that result in bleeding after cardiac surgery as well as current and emerging interventions to reduce bleeding and transfusion.
We discovered that of point-of-care (POC) tests of hemostatic function can facilitate the optimal management of excessive bleeding and reduce transfusion by facilitating administration of specific pharmacologic or transfusion-based therapy and by allowing physicians to better differentiate between microvascular bleeding and surgical bleeding. Emerging interventions like recombinant FVIIa have the potential to reduce bleeding and transfusion-related sequelae and may be life-saving; however, randomized, controlled trials are needed to confirm safety before they can be used as either first-line therapies for bleeding or bleeding prophylaxis.
In conclusion, careful investigation of the role of new interventions is essential as the ability to reduce use of blood products, to decrease operative time and/or re-exploration rates has important implications for overall patient safety and health care costs.     

氨甲环酸对减少肝切除术中出血的临床研究

目的观察氨甲环酸在肝切除术中止血的有效性和安全性及对凝血功能的影响。方法将2009年311月间收治的50例肝切除患者,随机分为对照组（C组）和氨甲环酸组（T组）各25例。T组给予氨甲环酸100mg/kg（总量≤5g）,C组给予等量生理盐水。于术前30min先给予负荷量20mL,剩下的则静脉泵入,泵注速度均为15mL/h。观察患者术中及术后出血和输血总量,比较患者术前和术后24h血常规和凝血功能状态。结果患者术前的一般情况无统计学差异（P〉0.05）。T组患者的术中出血和输血量均低于C组（P〈0.05）,且术后凝血功能改变无统计学意义（P〉0.05）。结论氨甲环酸在肝切除术中可以有效减少出血和输血量,且对术后凝血功能无显著影响,无严重不良反应,是一种安全有效的止血药物。