LAUSR

Hospital-acquired venous thromboembolism (VTE) incurs significant morbidity and mortality. Chemoprophylaxis is proven to reduce the risk of VTE and is recommended by guidelines. However, chemoprophylaxis increases the risk of bleeding. Therefore, chemoprophylaxis prescription requires balancing the risk of bleeding with thromboembolic protection. Currently, chemoprophylaxis usage is associated with the following issues: (1) Guidelines are outdated, unclear or poorly utilized. (2) Compliance is suboptimal, increasing the risk of VTE. (3) The optimal timing of perioperative administration is unclear leading to significant variations in practice. (4) The lack of standardization of chemoprophylaxis may adversely affect bleeding and/or VTE risks. The Perioperative Timing of Elective Chemical Thromboprophylaxis in General surgery (PROTECTinG) investigators, through the Victorian collaborative for Education, Research, Innovation, Training and Audit by Surgical trainees (VERITAS) has recently addressed these issues. PROTECTinG has delivered seven multi-site cohort studies and one multi-site survey over 2 years, including a total of 36 hospitals and 10 374 major elective abdominal surgeries across a variety of general surgery craft groups. These include abdominal wall, endocrine, colorectal, hepatobiliarypancreas and upper gastrointestinal surgery. The key findings from these studies are summarized below (Table 1): (1) Chemoprophylaxis administered before skin closure (preoperative and intraoperative initiation) offered no additional protection against VTE but increased the risk of major postoperative bleeding, blood transfusion and re-intervention, compared to postoperative chemoprophylaxis. (2) In patients with the highest baseline VTE risk, postoperative chemoprophylaxis, compared with its administration before skin closure, was still found to offer equivalent VTE protection whilst reducing the risk of postoperative bleeding. (3) Chemoprophylaxis can be safely administered at any time within the first 24 h post-surgery without adversely affecting VTE and bleeding risks.