Safe removal of an epidural catheter 72 hours after clopidogrel and aspirin administrations guided by platelet function analysis and thromboelastography
A 62-years-old man with a palpable mass in the popliteal fossa was found on magnetic resonance imaging (MRI) to have a thrombus-containing popliteal aneurysm. The patient had history of coronary artery disease for which percutaneous coronary intervention with single bare metal stent placement was done. Patient also suffered from hypertension, obstructive sleep apnea, paroxysmal atrial fibrillation, and a small infrarenal abdominal aortic aneurysm. Angiography demonstrated complete occlusion of the right popliteal artery caused by the aneurysm. Review of a recent 2D transthoracic echocardiography revealed normal left ventricular wall motion with ejection fraction (EF) of 55% and mild mitral regurgitation. He had completed a one-month course of clopidogrel therapy following bare metal coronary artery stent placement and was currently on aspirin 325 mg daily, which he discontinued 72 hours prior to surgery. Pre-operative laboratory tests were unremarkable including a hematocrit of 41%, platelet count of 166,000, and normal PTT, PT and INR.\nA lumbar epidural catheter was placed at the L3-L4 inter-space uneventfully on first attempt using an 18 G Tuohy needle with loss of resistance technique. A test dose of 3 mL of 1% lidocaine with epinephrine 1:200,000 was negative. The catheter was intermittently dosed to a total of 25 mL of 0.5% bupivacaine and a sensory blockade level of T6 was obtained. The patient underwent the resection of the thrombosed popliteal aneurysm with a saphenous vein graft interposition. He was hemodynamically stable throughout the procedure. Intra-operatively the patient received 10,000 units of heparin which was reversed after approximately 1 hour of anticoagulation with 75 mg of protamine. Following surgery he was transported to the ICU in stable condition. His pain was adequately managed postoperatively with Patient-Controlled Epidural Analgesia using a basal infusion of 0.2% ropivacaine at 10 mL/hour and a patient controlled bolus dose of 5 mL with a 30 minute lockout period. Immediately on arrival to the ICU he was started on enoxaparin 90 mg twice a day subcutaneously. The following morning he received one oral dose of clopidogrel 75 mg and Aspirin 325 mg accidentally.\nSeveral hours later anesthesia consult was sought to evaluate for epidural catheter removal. Aspirin and clopidogrel were then immediately discontinued in preparation for epidural catheter removal. Due to concerns for bleeding complications with epidural catheter removal in the setting of anticoagulation and antiplatelet therapy, the decision was made to remove epidural catheter 72 hours after the clopidogrel and aspirin dose contingent upon acceptable coagulation and platelet function parameters. The patient continued to receive subcutaneous enoxaparin 90 mg twice a day with the last dose being 24 hours before the planned epidural catheter removal. After approximately 72 hours had elapsed since receiving a dose of clopidogrel 75 mg and aspirin 325 mg, routine coagulation tests, platelet function assay (PFA) and thromboelastography (TEG) were obtained as shown in . The exact times medications were administered (last doses) relative to time of catheter removal are as following: Aspirin 325 mg orally at 0859 h on postoperative day 1; Clopidogrel 75 mg orally at 0859 h on postoperative day 1; Enoxaparin 90 mg subcutaneously at 0920 h on postoperative day 3 and epidural catheter removal at 0926 h on postoperative day 4.\nAfter a thorough discussion was made with the patient regarding the risk of epidural hematoma and patient's consent was obtained, the catheter was removed uneventfully. He was monitored in the surgical intensive care for two hours following catheter removal and was discharged home that evening in stable condition. Following discharge the patient was contacted by phone daily for one week to evaluate for symptoms of epidural hematoma. He remained asymptomatic and was restarted on clopidogrel 75 mg daily as an outpatient.