[Spinal anesthesia in a patient with SMON disease]

Area of Science:

• Neurology
• Anesthesiology
• Geriatric Medicine

Background:

• Subacute myelo-optico-neuropathy (SMON) is a neurological disorder.
• General anesthesia is often preferred for SMON patients due to potential complications with spinal anesthesia.
• This case involves an elderly patient with SMON and a femur neck fracture, who also presented with hypoxemia.

Observation:

• An 87-year-old female with a history of SMON (diagnosed at age 45) sustained a femur neck fracture.
• The patient exhibited significant hypoxemia (SpO2 77% on room air), making general anesthesia a less suitable option.
• Spinal anesthesia using bupivacaine and fentanyl was administered for the fracture repair.

Findings:

• The spinal anesthesia procedure at L3-4 resulted in a T4 sensory level.
• No severe lower limb pain was reported during the surgery.
• Post-operatively, the patient's neurological status (dysesthesia and reflexes) remained stable, similar to pre-operative levels.
• The neurotoxicity of bupivacaine is considered weaker than that of dibucaine, a factor in its selection.

Implications:

• This case suggests that spinal anesthesia with bupivacaine and fentanyl can be a viable and safe alternative to general anesthesia in select SMON patients, particularly those with respiratory compromise.
• Careful selection of anesthetic agents and monitoring are crucial for managing SMON patients undergoing surgery.
• Further research may explore the safety and efficacy of different anesthetic techniques in SMON patients.