Three-Times-Daily Subcutaneous Unfractionated Heparin and Neuraxial Anesthesia

Abstract

Subcutaneous (SC) unfractionated heparin (UFH) administered 3 times daily (TID) is widely used for venous thromboembolism prophylaxis in the perioperative period. There are no data in the literature regarding the incidence of adverse outcomes with neuraxial analgesia in the setting of this regimen. In this retrospective review, we report the incidence of untoward events related to anticoagulation with SC UFH TID in patients with indwelling epidural catheters. We queried the electronic hospital databases to identify patients receiving thoracic epidural analgesia in conjunction with 5000 U UFH SC TID from July 2008 to October 2010. In this group, we identified the diagnoses of neuraxial hematoma, deep vein thrombosis, or pulmonary embolism and examined measured blood coagulation parameters. In addition, we determined the percentage of patients receiving concomitant therapy with ketorolac. We identified 928 patients who received thoracic epidural analgesia in conjunction with 5000 U UFH SC TID during this period. There were no cases of neuraxial bleeding. Seven patients had a diagnosed deep vein thrombosis or pulmonary embolism. Thirty-four percent (315/928) of patients received ketorolac. The measured activated thromboplastin time was more than 40 seconds (35 seconds being the upper limit of normal) in 115 patients (12%). Given the rare incidence of neuraxial hematoma, statements regarding the appropriateness of epidural analgesia in the setting of TID SC UFH cannot be made from this limited sample size. At present, information regarding epidural hematoma in the setting of a TID SC UFH dosing regimen does not exist in the literature. Our study represents an initial step in the accumulation of data needed to prove or disprove the safety of this practice.