Intravascular thrombosis and thromboembolism during liver transplantation: antifibrinolytic therapy implicated? (73/402)

This case report describes a patient who underwent orthotopic liver transplantation and developed extensive hyperacute venous and arterial intravascular thromboses and thromboemboli intraoperatively. The patient was receiving antifibrinolytic therapy with aprotinin. The safety of routine aprotinin therapy in liver transplantation is examined. The value of the thrombelastograph (TEG) as a qualitative assessment of the coagulation system is emphasized.  (+info)

Low-dose oral vitamin K therapy for the management of asymptomatic patients with elevated international normalized ratios: a brief review. (74/402)

Asymptomatic elevation of the international normalized ratio (INR) is a common problem associated with hemorrhage. Evidence from randomized controlled trials supports the use of low-dose oral vitamin K therapy as a treatment that promptly reduces the INR. Vitamin K given orally is more effective than subcutaneous vitamin K injection, and as effective as intravenous administration when INR values are compared 24 hours after administration. A 1.0-mg vitamin K dose is likely most appropriate for patients with INR values between 4.5 and 10. The fear of over-correction of the INR has limited the widespread use of vitamin K; however, our review suggests that this occurs infrequently when small doses are administered orally.  (+info)

Tranexamic acid in primary CABG surgery: high vs low dose. (75/402)

AIM: Prophylactic administration of tranexamic acid decreases bleeding and transfusions after cardiac procedures but it is still unclear what the best dose and the most appropriate timing to get the best results are. METHODS: We enrolled 250 patients scheduled for elective, primary coronary revascularization. They were randomly divided into 2 groups. Group H received tranexamic 30 mg x kg(-1) soon after the induction of anaesthesia and a further same dose was added to the prime solution of cardiopulmonary bypass (CPB). Group L received tranexamic acid 15 mg x kg(-1) after systemic heparinization followed by an infusion of 1 mg x kg(-1) h(-1) till the end of the operation. Transfusions of bank blood products, bleeding in the postoperative period and coagulation profile were recorded. RESULTS: We did not find any difference between the groups either with respect to transfusion requirements or with respect to blood loss. CONCLUSION: For elective, first time coronary artery bypass surgery, both dosages of tranexamic acid are equally effective. Theoretically, it seems safer to administer it when patients are protected from thrombus formation by full heparinization.  (+info)

The effect of some epsilon-aminocaproic acid derivatives on platelet responses. (76/402)

epsilon-Aminocaproic acid (EACA) is a synthetic low molecular drug with antifibrinolytic activity. However, treatment with this drug can be incidentally associated with an increased thrombotic tendency. The aim of the present work was to test synthetic EACA derivatives for their antiplatelet activities. We investigated the effect of three EACA derivatives with antifibrinolytic activity: I. epsilon-aminocaproyl-L-leucine hydrochloride (HCl*H-EACA-L-Leu-OH), II. epsilon-aminocaproyl-L-(S-benzyl)-cysteine hydrochloride (HCl*H-EACA-L-Cys(S-Bzl)-OH) and III. epsilon-aminocaproyl-L-norleucine (H-EACA-L-Nle-OH) on platelet responses (aggregation and adhesion) and on their integrity. It was found that: 1. as judged by LDH release test, none of the tested compounds, up to 20 mM, was toxic to platelets, 2. in comparison with EACA, all the synthetic derivatives inhibited much stronger the ADP- and collagen-induced aggregation of platelets suspended in plasma (platelet rich plasma) and aggregation of these cells in whole blood, 3. EACA and its derivatives exerted a similar inhibitory effect on the thrombin-induced adhesion of platelets to fibrinogen-coated surfaces. Since platelet activation and blood coagulation are tightly associated processes, the antiplatelet properties of EACA derivatives are expected to indicate reduced thrombotic properties of these derivatives compared to EACA.  (+info)

Differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed normal or low calcium diet. (77/402)

The purpose of this study was to clarify the differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed a normal or low calcium diet. Ninety female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into nine groups with 10 rats in each group: baseline control, and 0.5% (normal) or 0.1% (low) calcium diet, either alone, or with vitamin K (30 mg/100g, food intake), vitamin D (25 micro g/100 g, food intake), or vitamin K + vitamin D. After 10 weeks of feeding, bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. Vitamin K supplementation increased the maturation-related cancellous bone gain and retarded the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation-related cortical bone gain in rats fed a normal calcium diet. Vitamin D supplementation reduced the maturation-related cancellous bone gain, prevented the reduction in periosteal bone gain, and enhanced the enlargement of the marrow cavity, with no significant effect on the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation- related cancellous and cortical bone gains with increased periosteal bone gain in rats fed a normal calcium diet. An additive effect of vitamin K and vitamin D on the maturation- related cortical bone gain was found in rats fed a normal calcium diet. This study shows the differential effects of vitamin K and vitamin D supplementation on cancellous and cortical bone mass in young rats fed a normal or low calcium diet, as well as the additive effect on cortical bone under calcium sufficient condition.  (+info)

Tranexamic acid for major spinal surgery. (78/402)

Patients who undergo major spinal surgery often require multiple blood transfusions. The antifibrinolytics are medications that can reduce blood-transfusion requirements in cardiac surgery and total knee arthroplasty. The present role of synthetic antifibrinolytics, especially tranexamic acid, in reducing peri-operative blood-transfusion requirements in spine surgery is still unclear. The majority of studies exploring the role of these drugs in spine surgery have limited patient enrollment and report mixed results. The goal of the present review is to discuss the pharmacology of tranexamic acid briefly. A brief synopsis of the studies using the synthetic antifibrinolytics for spine surgery is presented. Finally, the potential risks and the benefits of antifibrinolytics are discussed.  (+info)

Tranexamic acid reduces blood loss after cementless total hip arthroplasty-prospective randomized study in 40 cases. (79/402)

We investigated the effects of tranexamic acid in 40 patients who had received cementless total hip arthroplasty (THA) in a prospective, randomized study. In 20 patients, 1000 mg of whole-body tranexamic acid was administered intravenously 5 min before the operation started. The other 20 patients served as a control group and were operated on without tranexamic acid. Perioperative blood loss was similar in the tranexamic acid group and in the control group. Postoperative blood loss of the tranexamic acid group was significantly less than that of the control group at 2, 4, 6, 8, 10, and 12 h. Regarding time-related changes of postoperative blood loss, significant reduction was observed during the first 2 h after surgery in the tranexamic acid group ( P<0.001). After the first 2 h, there was no significant difference between the tranexamic acid group and the control group. Preoperative administration of tranexamic acid decreased postoperative blood loss until 12 h and total bleeding in cementless THA by reduction of blood loss during the first 2 h after surgery.  (+info)

Management of coumarin-associated coagulopathy in the non-bleeding patient: a systematic review. (80/402)

BACKGROUND AND OBJECTIVES: Excessive anticoagulation is a frequent complication of anticoagulant therapy. The risk of hemorrhage approximately doubles for each one point increase in the International Normalized Ratio (INR) above 3.0. Reducing a prolonged INR to within the desired therapeutic range requires that oral anticoagulants be withheld. In addition, vitamin K may be administered. Since this latter treatment can produce rapid reductions in the INR, it must be carefully tailored to meet individual needs, balancing the risk of bleeding against the potential risk of causing thromboembolism. METHODS: To review available literature on the management of coumarin-associated coagulopathy in asymptomatic patients, a Medline search was carried out and papers published in English from 1966 and 2003 were identified. All available information on the management of asymptomatic patients presenting with coumarin-associated coagulopathy was analyzed. RESULTS: Following the results of clinical studies that only used an elevated INR as a surrogate end-point for the risk of bleeding, low dose oral vitamin K appears as the preferable strategy for rapidly restoring therapeutic INR levels in asymptomatic patients who present with an excessively prolonged INR due to warfarin therapy. For the treatment of patients with asymptomatic acenocoumarol-induced coagulopathy, vitamin K does not add any benefit to the strategy of simply withholding oral anticoagulant treatment. INTERPRETATION AND CONCLUSIONS: Large randomized trials using clinical end-points are now required to provide evidence-based treatment recommendations for patients with coumarin-associated coagulopathy.  (+info)