Poster 179: Cauda Equina syndrome after spinal anesthesia with bupivacaine: a case report.

Abstract

Setting: Tertiary care hospital. Patient: A 83-year-old man. Case Description: The patient was admitted for orchiectomy. He received spinal anesthesia with 15mg of bupivacaine at the L5-S1 level. Approximately 24 hours later he developed severe pain, weakness, and sensory deficits in his lower extremities. Lower-extremity arterial and venous studies were unremarkable. The patient was diagnosed with probable cauda equina syndrome secondary to bupivacaine neurotoxicity. Assessment/Results: The patient was treated with steroids with little improvement. Subsequently, he was admitted to inpatient rehabilitation. Exam revealed hypersensitivity in the lower extremities. He had 3/5 lower-extremity strength bilaterally and was nonambulatory. Sensory exam and range of motion were limited by severe hyperesthesia. A catheter was required for urinary retention. The patient was started on a fentanyl patch, gabapentin (Neurontin), and physical and occupational therapy. By discharge, his pain, strength, and function had improved. He was ambulating 100ft with a walker, transferring with stand by assist, and was continent of bowel and bladder. He did, however, have persistent mild lower-extremity weakness and sensory deficits. Discussion: Spinal anesthesia with local anesthetics has been associated with cauda equina syndrome. Increased risk occurs with continuous spinal anesthesia, high doses, and use of lidocaine. Patients with underlying neurologic conditions may also have a higher susceptibility. The risk of cauda equina injury after bupivacaine spinal anesthesia is 1 in 10,000. The mechanism of neurotoxicity is unknown. Treatment is supportive and narcotic analgesics are typically required to control pain. Conclusion: Cauda equina syndrome is a rare complication of spinal anesthesia. It can cause significant pain and impairment.