Anticoagulation management in patient undergoing elective and emergency orthopaedic procedures

Abstract

INTRODUCTION Warfarin remains the treatment of choice for the majority of patients with venous thromboembolism, atrial fibrillation and valvular heart disease or valve replacement unless contraindicated. Poor management of patients on warfarin often leads to delay in surgery, life threatening bleeding during or after operation and unnecessary delay in discharge from hospitals in United Kingdom. METHODS We carried out a prospective study on patients who were on warfarin and underwent elective and emergency orthopaedic procedures during period of study- August 2007 to April 2008. All patients included in the study were identified from admission notes during period of study. All data regarding indications for warfarin, pre and post procedures INR, elective or emergency orthopaedic procedures and complications were collected using a standard proforma. RESULTS 18 patients, 12 male and 6 female were included into the study. Patients9 age ranged from 47-87 with mean of 76. The indications for warfarin therapy were atrial fibrillation in 12 patients, deep vein thrombosis in 5 patients and left ventricular aneurysm in 1 patient. 18 procedures, 10 elective and 8 emergency orthopaedic procedures were carried out during period of study. Elective procedures - 7 primary joint arthroplasty, 1 revision hip arthroplasty, 1 removal of metalwork and 1 metatarsophalangeal joint fusion. Emergency procedures - 4 hip hemiarthroplasty, 2 dynamic hip screw fixation, 1 external fixator application and 1 open reduction and internal fixation of ankle. All elective admission patients were pre-assessed in clinic prior to admission and were advised to stop warfarin based on their INR level. Patients with INR 2-3 had their warfarin stopped 4 days prior to surgery while patients with INR 3-4.5 had their warfarin stopped 5 days prior to surgery. This group of patients had their INR check on admission and ranged from 1.1-1.5. This group of patients had no reversal therapy and no cancellations were made to their operation. 8 emergency admission patients had INR of 1.4-4.7 on admission with mean of 2.7. 5 patients had reversal therapy while 3 patients had no reversal therapy. Pharmacological methods used to reduce the INR were fresh frozen plasma in 1 patient and Vitamin K in 4 other patients. 2 patients that received reversal therapy had operation on day 1, 2 on day 3 and 1 on day 5. 1 patient that had no reversal therapy was operated on day 1, 1 on day 3 and 1 on day 5. Patient that received no reversal therapy and operated on day 5 of admission died post-operatively from medical complications. Mean delay for patient that had reversal therapy was 2.2 days compared to 3 days in patient with no reversal therapy. All patients in this study had prophylactic low molecular weight heparin while off warfarin. Patients were recommenced on their normal dose of warfarin the day after their operation. DISCUSSION & CONCLUSIONS We conclude that patients on warfarin with INR 2-3 should have their warfarin stopped 4 days prior to surgery while patients with INR 3-4.5 should stop their warfarin 5 days prior to elective surgery. Trauma patients on warfarin requiring operation should have their INR reversed on admission to shorten delay in waiting time and improve outcomes.