Restricted spread of analgesia following epidural blood patch. Case report with a review of possible complications.

A complete restriction of upward spread of local analgesic solution in the epidural space is reported in a patient who three years earlier had received an epidural blood patch for post-spinal headache. Organisation of the blood clot with fibrous tethering of the dura to the wall of the spinal canal is suggested as the most likely cause of this apparent obstruction to spread. Other potential complications of epidural blood patch are presented. It is concluded from the literature on the subject that there is a need for a multi-centre analysis of the factors which might influence the incidence of inadvertent dural tap with an epidural needle.