Temporary interruption of warfarin ...

Temporary interruption of warfarin treatment is sometimes necessary when patients who require anticoagulant therapy ne surgery or other invasive measures Interruption of anticoagulant therapy can come in a significant increased risk for thromboembolic morbidity and mortality. Many different strategies for bridge therapy use short-acting anticoagulants in patients taking warfarin. single in kind strategy is to hospitalize patients and stop warfarin therapy four to five days before surgery using intravenous unfractionated heparin as the bridge anticoagulation. Another strategy uses low-molecular-weight heparin (LMWH) as the bridging anticoagulant. Despite these suggestions and the oftenness of this problem before surgery or an invasive act these strategies have not been studied vigorously. Douketis and colleagues evaluated the safety and efficacy of a standardized periprocedural anticoagulation regimen using LMWH

The consideration included consecutive adult patients who were onward warfarin therapy for thromboembolism prevention and had scheduled an elective surgery or invasive operation that required the normalization of the International Normalized Ratio (INR). All patients received a standard anti-coagulation regimen. Warfarin was stopped five to six days before the performance (see accompanying table). Three days before the operation LMWH (dalteparin) at a dosage of 100 IU by kg twice daily was started. The last dose of dalteparin was given no les than 12 hours before the action On the day of the management if hemostasis was adequate, warfarin was restarted, usually in the evening. If patients had a subdued risk for bleeding, dalteparin was restarted the following day at the preprocedural dosage and continued until the INR was at least 20 If the patient was at high risk for bleeding, no dalteparin was used, and the warfarin was continued. The major results measured during the study included thromboembolic circumstances major bleeding problems, and death. A secondary consequence was increased wound-related blood los in patients who were not at high risk for bleeding.

Of the 798 patients assessed, 650 participated in the cogitation Patients were followed for a mean of 138 days before and after the surgery or invasive course Two patients who were not at high risk for bleeding had throm-boembolic adventures (0.4 percent), and four had major bleeding episodes (07 percent) In this same assign places to there were 32 episodes (59 percent) of increased wound-related vital current loss that precluded the use of dalteparin after the measure The group of patients who had high-bleeding-risk deeds had two major bleeding disorders (18 percent) and sum of two units deaths (1.8 percent), which possibly were related to thromboem-bolic events

The authors infer that patients who receive chronic warfarin therapy and require temporary interruption of treatment can be managed with LMWH They note that this management strategy can be used with a depressed risk for thromboembolic and major bleeding complications.

Douketis JD et al. Low-molecular-weight heparin as bridging anticoagulation during interruption of warfarin: assessment of a standardized periprocedural anticoagulant regimen. Arch Intern M June 28 2004;164:1319-26

COPYRIGHT 2005 American Academy of Family Physicians

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