Incidental detection of pneumorrhachis in a young trauma patient following combined spinal–epidural anaesthesia: a case report

Pneumorrhachis — the presence of gas within the spinal canal — is an uncommon radiological finding that most clinicians encounter only once or twice during a career. At one end of the spectrum, it resolves without residual neurological deficit while on the other end, it may signal serious neurological deficit that demands prompt attention. In patients who have sustained trauma and subsequently require neuraxial anaesthesia, the aetiology of intraspinal air is rarely straightforward, since both mechanisms can independently contribute. A 19-year-old male presented following a road traffic accident with fractures of the left femoral shaft and multiple foot and hand bones. He underwent open reduction and internal fixation of the left femur under combined spinal–epidural anaesthesia. On the first postoperative day, he developed bilateral lower limb paraesthesia and left-sided motor weakness (3/5). Urgent CT of the dorsolumbar spine demonstrated epidural air at L2–L4 with paraspinal extension from L3 to S1. Subsequent MRI revealed paraspinal muscle oedema and an L4–L5 disc bulge indenting the thecal sac. The epidural catheter was removed, and high-flow oxygen with supportive analgesia was commenced. Neurological improvement was evident by the third postoperative day, and the patient was discharged on postoperative day 12 neurologically intact. This case draws attention to pneumorrhachis as an underappreciated complication at the intersection of trauma and regional anaesthesia. Conservative management produced a complete recovery, but the diagnosis required a structured clinical and radiological approach. Anaesthesiologists working with multiply injured patients should maintain awareness of this entity, particularly when postoperative neurological signs do not follow an expected pattern.