Background Historically, patients on warfarin who required invasive procedures were managed using intravenous heparin infusions. Warfarinised patients spent, on average, 6 more days in hospital.

Purpose To improve the management of patients on oral anticoagulation requiring invasive procedures.

Material and methods A new guideline replaced intravenous heparin with subcutaneous low molecular weight heparin (LMWH), allowing patients to return home before their oral anticoagulation had re-stabilised. Patients were stratified into high (HR), intermediate (IR) or low (LR) risk of thrombosis. All patients received a prophylactic dose LMWH immediately post-procedure: IR and HR patients had the dose escalated over 3 or 5 days. Pre-printed bridging plans gave guidance on reversal of anticoagulation, LMWH dosing and restarting warfarin. The appropriate plan was included in the patient’s notes or attached to the drug chart.

Following audit and review of incident reports, the anticoagulation pharmacist and consultant haematologist reviewed the guideline. LR and IR were combined into ‘standard risk’ (SR). A double sided ‘bridging prescription chart’ was developed, with tick boxes for risk stratification and LMWH dosing guide, and a pre-printed prescription for completion by the prescriber. It included information on reversal of oral anticoagulation pre-procedure, management of epidurals and restarting oral anticoagulation. The chart was piloted in the orthopaedic department and re-audited.

Results Initial audit identified incorrect risk stratification (8%), no bridging plan in notes (4%), incorrect LMWH doses (26%), high dose LMWH started immediately post-procedure (9% of IR and HR) leading to bleeding complications (10% major bleeding complication rate, expected 1–2%), LMWH doses not escalated in IR and HR patients (5%), co-prescription of LMWH when INR was therapeutic (2%) and incorrect warfarin prescription (10%).

Re-audit showed all patients were correctly risk stratified, prescribed and administered the correct LMWH doses, with a small improvement in warfarin prescription (8% incorrect). There were no thrombotic or bleeding complications. User feedback indicated that doctors, nurses and pharmacists felt more confident that they were giving appropriate treatment.

Conclusion Combining the clinical guideline and prescription appeared to improve the management of patients requiring peri-procedural anticoagulation bridging. It has now been introduced to all three hospitals.

References and/or Acknowledgements Dr Joost Van Veen, consultant haematologist.

Dr Peter Toth, associate specialist.

Claire Jarman, staff nurse.

Conflict of interest.