Risk of Venous Thromboembolism and Thrombophylaxis in Surgical Patients at a Tertiary Hospital in South-west Nigeria

Abstract

Venous thromboembolism (VTE) is an important complication of major surgery that may result in high morbidity and mortality. There is still however paucity of information on the prevalence, risk factors, prophylaxis and mode of treatment in this environment.

Aims and Objectives: The aim of this study is to determine the risk of developing VTE among major surgery patients and to evaluate the pattern of the thromboprophylaxis administered. 

Materials and Methods: All case notes of patients who underwent major surgery over a twelve month period were reviewed for clinical and radiological evidence of VTE and the pattern of thromboprophylaxis employed. 

Results: Three thousand and thirty-eight (3,038) casenotes were obtained and reviewed. The mean age was 43±16.3 years and 2,043 (67.2%) were females, 1209 from O&G. Of the 589 (19.4%) patients that received thromboprophylaxis, 531 (90.1%) were orthopaedic patients.  The most commonly used thromboprophylactic agent was LMW heparin (77.4%). The thromboprophylactic regimen was taken for less than a week in 459 (77.9%) patients. Clinically overt VTE occurred in 17 (0.56%) patients; 12 (0.39%) had deep venous thrombosis (DVT) while five (0.17%) developed PE. Six of the 17 (35.3%) had thromboprophylaxis (LMW heparin), but still developed DVT. Patients with clinically overt VTE had a significantly higher BMI than those without 28.5±0.86 vs 26.9±0.84 (p = 0.01).  

Conclusion: Although the prevalence of clinically overt VTE was low in this study, it was higher in overweight/obese patients, especially those with orthopaedic surgical intervention. The use of thromboprophylaxis was lower than expected.