Background and Objectives The authors report a case of unintentional subdural block in a parturient with prior Harrington rod insertion.

Methods The epidural technique was performed successfully at the L5-S1 interspace using the loss-of-resistance technique after two failed attempts at the L3-4 interspace.

Results Twenty to 30 minutes after total initial dose of 9 mL 0.25% bupivacaine with 1/200,000 epinephrine, the patient developed hypotension and a high sensory block involving the trigeminal nerve. The patient also complained of difficulties in swallowing and breathing. Signs and symptoms strongly suggested an unintentional subdural block. After careful monitoring and reassurance, the patient’s sensory level receded and she could breathe and swallow comfortably. Intubation was not required. The epidural catheter was maintained in the same space. The amount of 0.25% bupivacaine was reduced to 2 mL for subsequent top-ups. Adequate analgesia was provided throughout the course of her labor and delivery without other complications.

Conclusions Lumbar epidural anesthesia is not always an easily performed technique and is known to be associated with a higher incidence of complications in patients with prior Harrington rod insertion. Prompt recognition and proper management of subdurally placed needle and catheter avoided more serious complications.