Assessment of VTE prophylaxis using hematological parameters upon admission at a cancer care centre in London, England

Abstract

Introduction: Venous thromboembolism (VTE) risk assessments are essential for identifying patients at higher risk of developing VTE and minimising bleeding risk in those with lower risk. At St. Bartholomew's Hospital VTE risk assessments are conducted upon admission to the oncology wards. If prophylaxis is indicated, prescriptions for enoxaparin or direct oral anticoagulants (DOACs) should be documented in their chart, with doses administered unless platelet <75 x 109/L or clinicians recommend withholding them for upcoming surgical procedures. Inconsistencies in adherence to standardised protocols have been identified, resulting in some patients receiving inappropriate prophylaxis, while others in need have not been prescribed any, contributing to VTE development. This audit aims to identify current baseline VTE risk assessment documentation and whether patients receive prophylactic doses when clinically appropriate. Method(s): A prospective snapshot chart review was conducted using the electronic health record (CRS Millenium). All oncology patients on the 5A, 5B, 5C, 5D, and 6DA wards on Thursday May 20, 2024, were included in data collection. Data collected using a Microsoft Excel spreadsheet included VTE risk assessment results, prophylaxis indications, prescriptions and dosages, reasons for any withheld doses, and platelet counts. Chart notes, drug charts, and lab results found within CRS were utilised for data collection. Data were analysed using descriptive statistics. This audit was conducted as part of an NHS clinical service evaluation and did not require formal ethics approval. Result(s): A total of 85 patients were analysed, and 83 (97.6%) had a VTE risk assessment completed. Of these 72 (86.7%) were indicated for VTE prophylaxis and 56 had a prescription in their drug chart for a prophylactic agent. Of the 16 without a prescription in their drug chart despite indicating prophylaxis, 14 had platelets < 75 x 109/L, one needed further review, and one did not have a reason for not being on prophylactic therapy. Of the 56 that had prophylaxis indicated and a prescription in their drug chart, 46 had a prescription for enoxaparin, five for apixaban, two for edoxaban, one for aspirin and mechanical prophylaxis (anti-embolism stockings), and two for mechanical prophylaxis. Conclusion(s): In the oncology population at St. Bartholomew's Hospital, there was a lack of adherence to standardised VTE protocols. One patient received inappropriate prophylaxis, and two patients were not given their required prophylactic therapy doses. Data from this project will be utilised and distributed to oncology clinicians to emphasise the importance of following standardised protocols to prevent future VTE and bleeding events.