Venous thromboembolism after total knee replacement or total hip replacement: what can be learnt from root-cause analysis?

INTRODUCTION Because of the high risk of venous thromboembolism (VTE) in total hip replacement (THR) and total knee replacement (TKR), guidelines are used widely to enhance effective (yet safe) prophylaxis. If patients develop VTEs despite use of such guidelines, then the reasons are that the guidelines were: (i) followed but the VTE occurred anyway; (ii) not implemented appropriately. All VTEs are assessed routinely by root-cause analysis (RCA). METHODS The records and subsequent RCA reports for each patient who experienced clinically significant VTE after THR or TKR were reviewed. We established adherence to the guidelines (deemed to be 'unavoidable' with scope to improve the guidelines) and non-adherence (deemed to be 'avoidable' with scope to improve implementation). RESULTS Of 2,214 patients undergoing THR (n=1,330) or TKR (n=884), 25 (1.13%) experienced VTE. Four THR patients experienced VTE (2 of which were avoidable) and 21 TKR patients experienced VTE (5 of which were avoidable). There were significantly more VTEs in TKR patients than THR patients (p<0.0001). CONCLUSIONS A proportion of patients will experience VTE even if guidelines are followed (a baseline effect). Administration of chemical prophylaxis earlier might reduce this baseline effect further. This approach should be taken cautiously with due respect for the alternative risk of bleeding. Improvement in hospital routine may reduce the risk of VTE yet further.