Bleeding with anticoagulant therapy

Bleeding during anticoagulant therapy does not always correlate with prothrombin activity. Bleeding that occurs when the PT or INR is within the therapeutic range warrants investigation because it may unmask a previously unsuspected lesion (eg, tumor, ulcer). 

Pennir -van Beest F, Erkens J, Peteraen K-U, Koelz Herii R. Main ccxnedications associated with bleeding during anticoagulant therapy with coumarins. EurJ Clin Pharmacol (2005)61,439-44... 

Aging is one of the major risk factors for developing gastric ulcers because of an increased incidence of Helicobacter pylori infections and a widely spread use of non-steroidal anti-inflammatory drugs (NSAID). Co-morbidity, with the need for prophylactic medication with antiplatelet therapy, warfarin and other anticoagulants, also increases the risk of gastrointestinal bleeding and ulcerations (Murakami et al. 1968). 

Contraindications Epidural contraindicated in those patients with bleeding diathesis or infection at the injection site, those receiving anticoagulation therapy... 

The maternal rate of bleeding comphcations during heparin treatment is about 2%. This is consistent with the reported rates of bleeding associated with heparin therapy in non-pregnant women, and in warfarin therapy when used for the treatment of venous thrombosis (95). Subcutaneous heparin given just before labor can also cause a persistent anticoagulant effect at the time of delivery the mechanism of this prolonged effect is unclear (96). 

The prothrombin time (PT), as proposed by Quick, is the most commonly performed coagulation function test. It is used to monitor oral anticoagulant therapy and also as a preoperative screening test to warn of possible bleeding risk in patients with a personal or family history of bleeding (Table 36-2). Measured clotting times are extremely dependent on the animal and tissue source and the quality of the thromboplastin used. Variability can be expected because of the assay s dependence on the number of tissue factor molecules and the quantity of... 

Data from two large, randomized trials demonstrate that the use of low, fixed-dose warfarin (mean INR 1.4) combined with aspirin or of low-intensity anticoagulation (mean INR 1.8) monotherapy provides no significant clinical benefit compared with aspirin monotherapy but significantly increases the risk of major bleeding. Therefore, warfarin therapy targeted to an INR of less than 2 cannot be recommended for secondary prevention of CHD events following MI. 

In the absence of contraindications, the treatment of VTE initially should include a rapid-acting anticoagulant (e.g., unfractionated heparin [UFH], a low-molecular-weight heparin [LMWH], or fondaparinux) overlapped with warfarin for at least 5 days and until the patient s international normalized ratio (INR) is greater than 2.0. Anticoagulation therapy should be continued for a minimum of 3 months. The duration of anticoagulation therapy should be based on the patient s risk of VTE recurrence and major bleeding. 

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