Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis — A 12year study

The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital. We utilised a prospective audit database to identify those that had died within 42 and 90days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90day mortality rates. There were a total of 8277 elective primary TKR performed over the 12year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results. The mortality rates at 42 and 90days were 0.36 and 0.46%. There was one fatal PE within 42days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE’s occurred at 48 and 57days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%). Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.