False-positive epidural catheter aspiration tests in needle through needle combined spinal-epidural anaesthesia.

Abstract

We describe two separate episodes of free aspiration of clear fluid through epidural catheters during needle-through-needle combined spinal-epidural anaesthesia in the lateral position. Although both catheters were assumed to have been located intrathecally, both subsequently gave negative test doses and were used as epidural catheters. In the second patient, the position of the catheter was investigated using contrast spiral computerised tomography scanning, which showed epidural contrast spread only. This is the first time such an occurrence has been recognised, and we consider its significance for catheter site confirmation testing in combined spinal-epidural anaesthesia.