107YIELD OF CT BRAIN SCANS IN VERY ELDERLY PATIENTS WITH ACUTE CONFUSION: A RETROSPECTIVE STUDY AT A DISTRICT GENERAL HOSPITAL

Abstract

Background: Delirium is a common complaint in hospital with inpatient prevalence of delirium of up to 30 percent (Ryan et al, 2013). Many patients with delirium have neuroimaging performed, typically a CT Brain. Limited retrospective studies have shown that the yield of neuroimaging in this population is low (Hufschmidt et al, 2008) Method: This retrospective study considered patients over the age of 85 who underwent a CT head with the indication of new onset confusion (or related term) when seen in the Hereford County Hospital Emergency Department over a period of a year. Patients with lateralising neurology or clearly witnessed trauma/head injury were excluded. Main outcome measured was the presence of an acute abnormality on the CT (e.g. bleed, fracture, stroke). We also recorded use of anticoagulants and its association with a positive finding on CT, the number of CT scans done during the typical hours of sleep (10pm to 8am) and to what extent the CT scans with a positive finding impacted on management (qualitatively assessed). Result(s): There was a significant finding in 12/111 scans that were eligible for inclusion in the study (10.8%). In 12 patients due to inadequate or unobtainable documentation we were unable to accurately determine if the patient was on an anticoagulant at the time of CT. 15/99 (15.1%) of those scanned were on an anticoagulant although in our study only 1/11 positive scans were in patients on an anticoagulant (9.1%). 30/111 (27.0%) of scans were performed between 10pm and 8am and these were not more likely to have positive findings. Of the 12 positive scans, 7 were intracranial, subdural or subarachnoid haemorrhages, none of which had neurosurgical intervention and all of which were managed conservatively with a high mortality. 4 were ischaemic strokes (some subacute) given secondary stroke prevention and 1 showed a fracture (due to unwitnessed head injury). Discussion(s): The yield of CT Head in the very elderly (>85 years of age) presenting to our rural DGH was relatively low (10.8%) and as such this test could be reserved for those with a high index of suspicion for an intracranial cause and should not be considered a routine investigation.