To the Editor:—

We Support was provided solely from institutional and/or department sources. report the unnecessary removal of a correctly inserted epidural catheter. A 47-yr-old man underwent colostomy. After the surgery, a continuous epidural infusion of 0.25% bupivacaine (95 ml), to which buprenorphine 0.5 mg (2.5 ml) and droperidol 2.5 mg (1.0 ml) were added, was started at a rate of 2 ml/h. Before the patient left the postanesthesia care unit to the ward (2 h after the start of epidural infusion), we did an aspiration test, and 2.5 ml of clear fluid was relatively easily aspirated through the catheter. The glucose concentration of the aspirated fluid was 83 mg/dl and the blood glucose concentration was 73 mg/dl. Two hours later, 1.8 ml of clear fluid was again easily aspirated through the catheter. It contained 100 mg/dl of glucose. Although there was no definite motor block of the lower limbs, the epidural catheter was removed because subarachnoid catheter migration could not completely be ruled out due to the high glucose concentration of the fluid. After removing the epidural catheter, we checked the insert packed with the buprenorphine. It stated that this commercial buprenorphine contained “50 mg per ml of glucose.” The glucose concentration of the fluid in the infuser we used was calculated to be 127 mg/dl (125 mg of glucose in 98.5 ml). Buprenorphine used in the United States and United Kingdom also contains 50 mg/ml of glucose.