RADIOLOGICAL EXAMINATION OF THE INTRATHECAL POSITION OF MICROCATHETERS IN CONTINUOUS SPINAL ANAESTHESIA

There have been few studies of the intrathecal position of spinalcatheters in continuous spinal anaesthesia. This prospectivestudy was designed to examine radiologically the intrathecalposition of 28-gauge spinal catheters. We studied the entryinto the subarachnoid space and the intrathecal position of68 spinal catheters. In 50%, the catheters passed in a cranialdirection, in 34% the catheters remained at the level of thepuncture site and in 16% the catheters were directed caudally.The intrathecal position of the catheters did not depend onthe level of the lumbar puncture (P = 0.6246), but was dependenton the position of the patient during insertion of the catheter(P = 0 0093), and on the depth of insertion (P = 0.0099). Ourstudy sug gests that patients should be in a sitting positionduring insertion of a subarachnoid microcatheter and that thedepth of insertion should not exceed 4cm. (Br. J. Anaesth. 1993;71: 803–806)