Patterns of thromboprophylaxis among orthopaedic surgery patients at Kenyatta National Hospital, Kenya

Abstract

Introduction: Venous thromboembolism (VTE) is an important complication of major orthopaedicsurgery and is associated with short and long term morbidity and increased mortality. Current international data suggest that in the absence of thromboprophylaxis, deep vein thrombosisoccurs in about 50 % of patients undergoing elective hipor knee arthroplasty and fatal pulmonary embolism may occur in approximately (1.7 %) of patients undergoing knee arthroplasty.Current management guidelines recommend that thromboprophylaxis should be used routinely in such patients. Despite the existence of national and international guidelines, thromboprophylaxis is underutilised in orthopaedic surgery patients. The significance of such under use of thromboprophylaxis therapy is underscored by the fact that pulmonary embolism remainsthe most common preventable cause of death in hospitalized patients. There was limited datafrom the resource challenged countries, including all East African countries on the extent and pattern of thromboprophylaxis in orthopaedic surgery, and hence the impetus for the present study. Purpose: The purpose of this study was to find out the trends of prophylaxis of venous thromboembolism among orthopaedic surgery patients at Kenyatta National Hospital. Study setting: Kenyatta National Hospital Medical Records Department. Study area: The study was carried out at the Kenyatta National Hospital, medical records unit. Kenyatta National Hospital serves as a public referral and the teaching hospital. It is the largest hospital in Eastern Africa. Study design and Methodology: A retrospective descriptive study of medical records. Medical records data of patients who had undergone orthopaedic surgery between January, 2009 and December, 2010 and met the study inclusion criteria were reviewed and abstracted using a validated data collection tool. Study population: Adults aged 18 years and above who underwent orthopaedic surgery as inpatients between January, 2009 and December, 2010. Data analysis: Information obtained was coded and entered into a computer database using excel package program and analysed using Statistical Package of Social Science (SPSS) version 13.0. The results were then presented in form of graphs, charts and tables. Descriptive statistics were used to summarize the results. Statistical significance were determined using Odds ratio (OR) and p, value. Results: A total of 175 files were retrieved for the study based on sample size required and the eligibility criteria. The mean age of participants was 43.7 years with standard deviation of 17.9 (95 % Cl: 41.1-46.4). Sixty six percent of the participants were male while forty four percent were female. VTE prophylaxis was used in 31 (17.7 %) of the participants during pre operative procedure and 66 (37.7 %) of the participants during post operative procedure. Enoxaparinand UFH was prescribed to 63 (95.5 %) and 3 (4.5 %) participants respectively. No mechanical prophylaxis was employed. Out of 66 participants who received thromboprophylaxis during post operative procedure only 41.8% received adequate prophylaxis. Three participants were identified with clinical contraindications to VTE prophylaxis, 2 (2.5 %) participants were due to active bleeding and I (1.3 %) was due to hypersensitivity. The common reported risk factors for VTE were immobility (>4 days) (100 %), trauma 98.9 %, increasing age (>40 years) (48.6 %) and wound infection (10.9 %). The odds ratio of VTE were high to those participants with increasing age >40years and heart failure, 3.26 (95 % CI: 0.26- 82.91) and 18.67 (95 % CI: 0.00- 367.92). Conclusion: Venous Thromboembolism prophylaxis is underutilized at KNH orthopaedic surgery and there is a significant gap between evidence based thromboprophylaxis recommendations and actual clinical practice. Recommendation: All patients undergoing major orthopaedic surgical procedures should routinely receive anticoagulant prophylaxis unless they have contraindications to anticoagulation. However, patients should be encouraged to ambulate as early as possible and as frequent as possible. Kenyatta National Hospital should have a formal written thromboprophylaxis protocol of it is own, as advised by American College of Chest Physicians, which will close the gap between guideline recommendations and clinical practice.