Are patients on warfarin with high INR treated according to published guidelines?

摘要

Objective: Australasian guidelines for the treatment of over-anticoagulation have been published. We aimed to determine whether emergency department [ED] patients taking warfarin who have high INR were treated according to guidelines.Methods: This retrospective observational study included ED patients taking warfarin with INR ≥ 4. Data included demographics, warfarin indication, bleeding evidence and subsequent management. Outcome of interest was proportion treated according to guidelines; analysed by descriptive statistics.Results: 201 patients were studied; median age 74 years, 47% female. Atrial fibrillation was the main indication for warfarin [63%]. 48 patients [24%] presented with bleeding, of which 22 were classified as major bleeds. All patients with major bleeding received reversal treatment; with 64% receiving recommended triple therapy. 33% in the non-bleeding group received reversal treatment.Conclusion: There was reasonably good compliance with the guidelines, especially for patients with major bleeding. Vitamin K doses were suboptimal in a significant proportion of cases. Support: This work was undertaken with departmental funds only. No external support was received. Introduction An elevated INR is a major determinant in the risk of bleeding in anticoagulated patients. 1 , 2 Previous research has established a high prevalence of a supra-therapeutic INR in the Emergency Department [ED] population taking warfarin. 3 In 2004, the Warfarin Reversal Consensus Group, on behalf of the Australasian Society of Thrombosis and Haemostasis, published consensus guidelines for warfarin reversal. 1 The aim of this study was to determine whether patients taking warfarin who have an abnormally high INR measured in the ED are being treated according to those guidelines. Methods This observational study was conducted by explicit retrospective medical record review. 4 Participants were patients on warfarin presenting to the ED of Western or Sunshine Hospitals [community teaching hospitals with annual ED census of 33,000 and 60,000 respectively] during the period January 2006 and June 2007 who had an INR reading of ≥4. Patients were identified from a pathology database. Data was collected onto an explicit data form. Data collectors were not blinded to the study hypothesis. Data collected included demographics, indication for warfarin, evidence of bleeding, subsequent treatment and ED disposal. Patients who experienced bleeding were categorised as major and minor. Major bleeding was defined as gastrointestinal bleeding [haematemesis and/or malaena], intracranial haemorrhage and any bleeds that led to subsequent haemodynamic compromise or need for surgery. This group was considered to correlate with the ‘clinically significant' category identified in the guidelines. Minor bleeds were defined as uncomplicated bleeds which self ceased and did not have any of the above features. This group included bruising. INR was measured by the hospital pathology service. The upper extreme could only be set at the highest reporting point of the laboratory: [INR>8.5]. The guideline treatment of INR >9 was interpreted as applying to INR>8.5. Treatment was classified as reduction or cessation of warfarin therapy, administration of Vitamin K, Fresh Frozen Plasma [FFP], Prothrombinex or combinations of these.The primary outcome of interest was the proportion of patients treated according to the Australasian guidelines for management of over-anticoagulation. Data was analysed using descriptive statistics. A study period, starting a year after the guidelines were disseminated, was chosen to allow time for the guidelines to have been implemented while giving a sample size such that reasonable conclusions could be drawn. Our aim was 150 patients. The study was approved as a quality improvement activity under the NHMRC Quality Assurance guidelines and formal ethics approval was not required. Results 201 patients were included in the analysis. The derivation of