Intraoperative Epidural Catheter Malfunction

A 62-yr-old obese male (120 kg, 190 cm tall, body mass index 33.2 kg/m²), American Society of Anesthesiologists physical status II, is scheduled for a colectomy secondary to ulcerative colitis. You plan a combined general anesthetic technique with an epidural. When the patient is in the operating room, you place an epidural catheter (20-gauge closed tip) (B. Braun Medical, Inc., Bethlehem, PA) uneventfully in the L4-5 interspace. The length of the epidural catheter in the epidural space is 4 cm. As is your practice, the epidural catheter, as it leaves the patient’s back, is led in a semicircle over a folded 2 × 2 inch swab. This is then covered with an OpSite (Flexigrid; Smith and Nephew, Hull, England). The catheter is attached to the patient’s back and over his right shoulder using Compound Benzoin Tincture U.S.P. (The Clinipad Corporation, Guilford, CT) and tape (Hytape Surgical Produce Corporation, Yonkers, NY). There is a negative test to 3 ml of lidocaine 2% with epinephrine 1:200,000. A total of 22 ml of lidocaine 2% is then injected and a block to T-4 is achieved. The patient is placed in a supine position and routine general anesthesia commenced. Two additional boluses are injected into the epidural space with good effect and no problem. Forty minutes after the last dose, the surgeon requests that the patient be placed in a steep head-down position. Shortly thereafter, it becomes impossible to inject anything through the epidural catheter, despite the use of a small syringe. You suggest that the surgeon puts the table back in the original position, but he is unwilling to do so at that time. You are reluctant to abandon your epidural. Is there anything else you could do to get the epidural to function adequately again?