AN AUDIT: THROMBOPROPHYLAXIS FOR TOTAL HIP REPLACEMENT PATIENTS AT NORTHWICK PARK AND CENTRAL MIDDLESEX HOSPITALS

It is well documented that hip replacement surgery is associated with a high rate of post-operative venous thromboembolism (VTE). A review of the literature performed by the National Institute of Clinical Excellence (NICE) revealed that after elective hip replacement surgery the DVT incidence was found to be 44% and the PE incidence to be 3%. In addition, compared to no prophylaxis, 28 randomised controlled trials found LMWH to reduce the risk of DVT by 51% and that of PE by 64%. NICE recommended that patients undergoing total hip replacement (THR) surgery with one or more risk factors for VTE should receive four weeks of either low molecular weight heparin or fondaparinux therapy post-operatively. The British Orthopaedic Association (BOA) subsequently reported this guidance as generic and not context or operation specific. This has lead to confusion amongst Orthopaedic surgeons with regard to the duration of anticoagulation following a THR. We performed an audit to determine whether patients undergoing a THR at Central Middlesex (CMH) and Northwick Park Hospitals (NPH) receive the trust policy of low molecular weight heparin for 10 days post-operatively. We retrospectively analysed 94 patients over the age of 60 who had a THR (both electively and after a fractured neck of femur) between April 1 st 2007 and August 21 st 2008 at CMH and NPH. Only 43% of patients received prophylactic anticoagulation for 10 days or more after their THR. Four of the ninety-four patients suffered a VTE post-operatively. The rate of deep vein thrombosis was 2.1% and of pulmonary embolus was 3.2%. It is possible that the poor adherence to the trust guideline for post-THR thromboprophylaxis accounted for the high incidence of VTE noted in the study. It is important that VTE incidence is reduced to prevent significant mortality and morbidities. In addition, there can also be costly medico-legal implications if a patient develops a VTE and their caregivers have not complied with prophylactic guidelines. Better education of healthcare professionals regarding existing hospital policies may help to reduce the poor compliance rates found. Further guidance from the BOA may provide a gold standard policy for anticoagulation following THRs to ensure a lower incidence of VTE in the future. Abbreviations: VTE - Venous thromboembolism DVT - Deep Vein Thrombosis PE - Pulmonary Embolus NICE - National Institute of Clinical Excellence LMWH - Low Molecular Weight Heparin BOA - British Orthopaedic Association CMH - Central Middlesex Hospital NPH - Northwick Park Hospital THR - Total Hip Replacement KeyWords: Orthopaedic, Hip replacement, Thromboprophylaxis, Venous thromboembolism, Deep vein thrombosis, Pulmonary embolism