Continuous Lumbar Plexus Catheter Removal in Postoperative Total Hip Replacement Patients Receiving Warfarin Thromboprophylaxis: A Retrospective Analysis

Background and Objectives: Based on the case reports of hemorrhagic complications, recommendations for the removal of lumbar plexus catheters in anticoagulated patients were created. These guidelines are controversial as they limit the use of lumbar plexus blocks in postoperative anticoagulated patients. This study was designed to evaluate the incidence of hemorrhagic complications and coagulation status using International Normalized Ratio (INR) at the time of lumbar plexus catheter removal in patients receiving warfarin after total hip replacement. Methods: A retrospective study of 371 patients on warfarin thromboprophylaxis who received continuous lumbar plexus catheters for postoperative analgesia after total hip surgery was performed. The primary outcome measure was the incidence of bleeding complications after catheter removal; secondary outcome measures included warfarin dose, bridge therapy, incidence of deep vein thrombosis, pulmonary embolism (DVT/PE) and INR values upon catheter removal. Results: Almost all lumbar plexus catheters (93%; 344/371) were removed at 72 hours. At the time of catheter removal, mean INR was 1.99 [1.42-2.41] (p = 0.015); 67% of patients had an INR > 1.5 and half of these patients had INRs between 2.0-3.0; 5% had INR’s between 3.0-4.0. There were no adverse bleeding complications or nerve injury after the removal of catheters. Conclusions: We observed no incidence of bleeding after lumbar plexus catheter removal despite 67 % of patients demonstrating INR’s > 1.5. Our retrospective analysis illustrates the relative safety of catheter removal in anticoagulated patients and suggests that the removal of lumbar plexus catheters can be safely performed with an INR > 1.5 in patients receiving warfarin.