International normalized ratio and prothrombin time values before the removal of a lumbar plexus catheter in patients receiving warfarin after total hip replacement.
BACKGROUND
There is a paucity of data regarding the coagulation status when discontinuing perineural catheters in patients receiving anticoagulant after operation. This retrospective study was designed to establish international normalized ratio (INR) and prothrombin time (PT) at the time of removal of lumbar plexus perineural catheters in patients receiving warfarin after total hip replacement.


METHODS
Patients who received a continuous lumbar plexus nerve block for postoperative analgesia and received warfarin after total hip surgery between August 2002 and June 2007 were included in this retrospective study. PT and INRs were recorded before surgery and every day after operation along with any post-surgical nerve injury and bleeding related to the removal of the perineural catheter.


RESULTS
Six hundred and seventy patients met the inclusion criteria. Almost all lumbar plexus catheters (89%) were removed on postoperative day 2. At the time of the perineural catheter removal, 36.2% of patients had an INR >1.4 (range: 1.5-3.9). One case of local bleeding was recorded at the time of the catheter removal with an INR of 3.0. This was managed with a direct pressure at the site.


CONCLUSIONS
Although in this retrospective analysis, we demonstrated that lumbar plexus catheters were removed with an INR > or =1.5, additional data are required to confirm the safety of such an approach.
Department of Anesthesiology, University of Pittsburgh Medical Center, UPMC Shadyside Hospital, Suite M104 (Posner Pain Center), 5230 Centre Avenue, Pittsburgh, PA 15232, USA. chelje@anes.upmc.edu
J E
JE
Chelly
D M
DM
Szczodry
K J
KJ
Neumann
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage*; D019644:Arthroplasty, Replacement, Hip; D001777:Blood Coagulation / Q000187:drug effects*; D002406:Catheterization, Peripheral / Q000295:instrumentation; D020878:Device Removal; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008160:Lumbosacral Plexus; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000295:instrumentation*; D010149:Postoperative Pain / Q000628:therapy; D011182:Postoperative Care / Q000379:methods; D011517:Prothrombin Time; D012189:Retrospective Studies; D014859:Warfarin / Q000008:administration & dosage*
D000925:Anticoagulants; D014859:Warfarin