Cauda equina syndrome following combined spinal and epidural anesthesia: a case report.

Purpose: To describe a case of complete neurological recovery from cauda equina syndrome lasting ten months following spinal anesthesia with 0.5% hyperbaric bupivacaine and epidural anesthesia with ropivacaine, and to discuss the possible mechanisms involved.

Clinical Findings: A 79-yr-old man with Paget's disease was scheduled for surgery to remove a skin tumour below his scrotum. He had no history of radicular pain or back pain and no pre-existing neurologic disorder. Surgery was performed with the patient in the supine position. He received 0.5% hyperbaric bupivacaine intrathecally for the procedure and ropivacaine through an epidural catheter for postoperative pain management. After catheter removal, the patient developed urinary retention, fecal incontinence, and perianal hypoesthesia. A lumbosacral magnetic resonance imaging (MRI) revealed no tumour, infarction, degeneration, spinal stenosis, or compression on the cauda equina nerve roots. A diagnosis of cauda equina syndrome was made, and the etiology was thought to be toxicity of bupivacaine either alone or in combination with ropivacaine. After three months, the patient reported some return of sensation at the perianal area, with complete resolution at four months. At the ten-month follow-up visit, the patient had recovered from his urinary retention and fecal incontinence.

Conclusion: This case suggests that spinal anesthesia, even with an ordinary dose of hyperbaric 0.5% bupivacaine, might induce cauda equina syndrome in older patients.