Spinal subdural haematoma as a complication of immediate epidural blood patch.

PURPOSE: The authors report a case of a patient who developed spinal subdural haematoma after a series of epidural blood patches to alert anaesthetists to this rare complication.

CLINICAL FEATURES: The patient was a 35-yr-old woman without coagulopathy and was initially treated elsewhere for chronic pain by repetitive epidural phenol injections. When the dura was inadvertently punctured during subsequent attempts to inject phenol, immediate epidural blood patch was performed to treat or prevent headache. The patient developed cauda equina syndrome after six epidural blood patches. The clinical diagnosis was confirmed by magnetic resonance imaging and the intradural haematoma was evacuated surgically. The patient made a complete recovery.

CONCLUSIONS: Epidural blood patch is not without complications. Transient backache and/or radiculopathy may occur in up to one-third of patients receiving a blood patch. If signs and symptoms continue or worsen, a spinal subarachnoid and/or subdural haematoma should be suspected and neurosurgical opinion sought. The technique used to identify the epidural space is important in preventing subdural injection of blood. The needle should be withdrawn after dural puncture and the epidural space identified at a different level. Blood patches may carry a higher risk of serious complications after multiple epidural phenol injections because of fibrosis and obliteration of the epidural space. Magnetic resonance scans reliably demonstrate the extent of the pathology. If diagnosed and treated before irreversible changes occur, spinal intradural haematoma can result in complete recovery.