Computed tomography head scans prior to lumbar punctures in suspected meningitis

The literature suggests that certain clinical criteria to determine raised intracranial pressure (ICP) should be met if a patient suspected of meningitis is to undergo a computed tomography (CT) head scan prior to having a lumbar puncture (LP).

To evaluate whether these criteria were being used by the general medicine department of Auckland City Hospital when requesting CT scans prior to LPs in patients with suspected meningitis.

A total of 37 patients admitted under general medicine with suspected meningitis from 1 January to 31 July 2016 were retrospectively audited based on the clinical evidence justifying the decision to do a CT scan prior to a LP.

Only 7 of 24 patients who underwent CT scans had met clinical criteria for raised ICP. There were no abnormalities found on any of the CT scans and approximately two-thirds of these patients had a final diagnosis of viral illness or headache.

A large number of patients with suspected meningitis under general medicine at Auckland City Hospital are having CT scans without clinical evidence suggestive of raised ICP.