Management of Over‐Anticoagulation in Warfarinised Hospital Patients

Abstract

Aim To determine the number of warfarinised hospital patients experiencing over‐anticoagulation; to identify how over‐anticoagulation is managed and whether local guidelines are adhered to. Method 2 prospective one‐week clinical audits were conducted in 2005 (Audit 1) and 2008 (Audit 2). The medical notes, drug charts and anticoagulation charts of warfarinised patients admitted to hospital were reviewed. The following data were collected: medical histories, warfarin regimen, international normalised ratio results, clinical events and over‐anticoagulation clinical management and treatment options. Results Data were collected for 58 patients (Audit 1: n = 30; Audit 2: n = 28). At least one‐third of all patients experienced over‐anticoagulation (Audit 1: 53%; Audit 2: 36%). Haemorrhagic events occurred in 40% of patients in Audit 1 and 18% in Audit 2 (p = 0.06) – not all were associated with elevated international normalised ratios. Most cases of over‐anticoagulation were managed by withholding warfarin doses and one case (Audit 2) required Prothrombinex. Drug interactions were the most common risk factor (> 50% of patients) for over‐anticoagulation in both audits. Problems with documentation were more prevalent in Audit 1 than in Audit 2. Conclusion Over‐anticoagulation is a common occurrence in warfarinised hospital patients. Hospital over‐anticoagulation management practices need to be reviewed to ensure safe and efficacious anticoagulation.

Documentation of Warfarin Education provided to Hospital Patients: A Clinical Audit

“…omeprazole, aspirin) and, if not monitored could affect the patient's warfarin therapy, including increasing the risk of major bleeding. 5,6,16,17,20 These results, reinforce the need for warfarin education for this group of hospitalised patients.…”

“…1,2 However, warfarin use is challenged by its narrow therapeutic index, complex pharmacology and preventable adverse events. [3][4][5][6] Consequently, education for patients prescribed warfarin is critical to ensure optimum efficacy and medication safety. 7,8 Provision of warfarin education to patients in different clinical settings is inadequate with over 50% of hospital patients receiving little or no warfarin education from health professionals during their admission.…”

“…6,8,9 This is concerning because patients who are started on warfarin in hospital are at an increased risk of warfarinrelated adverse events while in hospital, and are at a tenfold increased risk of serious bleeding within the first month of therapy post-discharge. 5,10 The Australian National Inpatient Medication Chart (NIMC) highlights the importance of warfarin education by the inclusion of a Warfarin Education Record (WER). 11 It is not known to what extent the NIMC guidelines, with respect to the provision and documentation of warfarin education to hospital patients, are followed.…”

Prothrombin complex concentrates used alone in urgent reversal of warfarin anticoagulation

“…As anticoagulation with warfarin is effective in the treatment and prevention of thromboembolic events, it is the most widely used oral anticoagulant worldwide. There are almost one‐quarter of a million patients prescribed warfarin therapy in Australia, 1 with this number expected to grow by approximately 9% per year 2 …”

“…There are almost one-quarter of a million patients prescribed warfarin therapy in Australia, 1 with this number expected to grow by approximately 9% per year. 2 Warfarin has a narrow therapeutic index, hence regular monitoring is required, with the typical therapeutic international normalized ratio (INR) range defined as between 2.0 and 3.0 (extending up to 3.5 for some indications, e.g. mechanical mitral valve).…”