Traumatic pneumomyelogram. Implications for the anaesthetist.

A 70-year-old man sustained a severe head injury following a fall downstairs, which resulted in him being found in a head down position. In the accident and emergency department he was noted to have subarachnoid air on a lateral cervical spine radiograph. This drew attention to the presence of fractures in the middle cranial fossa and nitrous oxide was immediately discontinued. The presence of a traumatic pneumomylogram implies a base of skull or middle cranial fossa fracture, and is almost certainly associated with intracranial subarachnoid air. Early recognition of the condition, and cessation of nitrous oxide, is essential to prevent dangerous increases in intracranial pressure secondary to the diffusion of gas into the air filled cavity.