Warfarin toxicity in the emergency department: Recommendations for management

Abstract

Objective: To examine patients who presented to a hospital emergency department with evidence of warfarin toxicity, and to review the available published literature to determine what guidelines are available for management of this problem. Method: A retrospective analysis of all adult patients who presented to The Geelong Hospital Emergency Department between 1 January 1996 and 30 June 1998 with international normalized ratio > 6 due to warfarin toxicity. Results: A total of 84 patients with international normalized ratio > 6 were included in the study. The average age was 68.3 years. Fifty‐three per cent were women. The international normalized ratio was between 6 and 10 in 33 patients (39%), and greater than 10 in 51 patients (61%). Major bleeding occurred in 16.7% of patients, minor bleeding in 17.8%. Sixty‐five per cent had no bleeding. Seven patients died, four of those with bleeding. Patients with an international normalized ratio > 10 were more likely to receive fresh frozen plasma (77.6%vs 28.6%; P < 0.001) and in greater amounts (3.0 units vs 0.8 units; P < 0.001) than those with an international normalized ratio of 6–10. There were also more episodes of major bleeding, although not significant. Patients with major bleeding were older (mean 75.4 years vs 67.5 years; P = 0.04), more likely to be admitted (P = 0.046), were more often given fresh frozen plasma (P = 0.003) and in greater amounts (3.28 units vs 2.0 units; P = 0.02). Conclusion: Warfarin toxicity is a common problem, and variation in management is not surprising considering the lack of consensus in the literature on this topic. Current recommendations are summarized and a simple flowchart for management of this problem is provided.