The safe use of epidural anesthesia after subcutaneous injection of low-dose heparin in general abdominal surgery

OBJECTIVE: To determine if epidural anesthesia after the subcutaneous injec tion of low-dose unfractionated heparin (LDUH) in patients who undergo elec tive bowel surgery is safe with respect to hemorrhagic complications. DESIGN: A prospective cohort study. SETTING: Two hospitals affiliated with the Universite de Montreal. PATIENTS: Fifty patients scheduled for elective bowel surgery, INTERVENTION: Subcutaneous injection of 5000 units of LDUH and elective sur gery for colonic carcinoma, chronic diverticulosis or inflammatory bowel di sease. MAIN OUTCOME MEASURES: Activated partial thromboplastin time (APTT), anti I Ia and anti-Xa heparin levels measured before and 2 and 4 hours after injec tion of LDUH. RESULTS: In no case was the heparin anti-IIa or anti-Xa level higher than 0 .20 U/mL, which is considered a significant detectable level of heparin. CONCLUSION: LDUH given subcutaneously is not associated with significant de tectable heparin levels, so epidural anesthesia should be safe when perform ed 2 hours after LDUH injection in patients who undergo general abdominal s urgery in the absence of any other impairment of hemostasis.