Documentation of SIGN 157 indications on CT head requests for delirium in ED, OPED and AMU

Introduction: Older patients admitted with delirium are often sent for a CT head. SIGN 157 says the scan should only be requested if there is new focal neurology, unexplained reduced consciousness, a recent fall, a head injury or anticoagulation. Without one of those, the scan very rarely shows anything that explains the delirium, This may lead to issues such as unnecessary radiation exposure, delay in treatment/diagnosis and cost etc. We wanted to know how often requests recorded a valid reason for the scan.

Method: We looked at every CT head requested for patients aged 65 and over with coded delirium from the Emergency Department, the older people's ED and the Acute Medical Unit at one teaching hospital. Cycle one covered September to December 2025 and cycle two March to June 2026. Each request was assessed against the SIGN 157 indications. The standard was 100%. After cycle one we fed the results back to acute medicine and older people's medicine and put the SIGN criteria up where scans are requested.

Results: There were 118 scans in cycle one and 127 in cycle two. Compliance rose from 72% to 82%. A recent fall was the commonest reason given in both cycles. The diagnostic yield was low, with acute intracranial pathology found in 2 scans in cycle one and 7 in cycle two. Several requests recorded a reason that did not hold up e.g confusion with background of dementia, anti-platelet therapy, a scan requested after no infection was found/normal bloods etc.

Conclusions: Feedback and a poster improved documentation by ten points, but nearly one in five requests still gave no valid reason for the scan, and the scans themselves rarely changed the picture. A third cycle will be led by older people's medicine team.