Warfarin toxicity in the emergency department: recommendations for management

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.

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.

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).

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.