LO059: CT head scans yield no relevant findings in patients presenting to the emergency department with bizarre behavior

Abstract

Introduction: The standard approach between Emergency Departments (EDs) and Psychiatric Emergency Services is to medically “clear” a stable patient of organic pathology prior to psychiatric consultation. Medical clearance involves neuroimaging, typically in the form of a computed tomography (CT) head scan. This study examines the clinical impact of ordering CT head scans for patients presenting with bizarre behaviour. Methods: A 5-year retrospective chart review was conducted at 3 academic, urban ED sites. Inclusion criteria were patients ≥18 years of age triaged as “mental health - bizarre behavior” (defined as deviating from normal cognitive behaviour with no obvious cause) with a CT head scan ordered while under the care of the ED. Exclusion criteria were focal neurologic deficits on exam, alternative medical etiology (i.e. delirium, trauma) and/or pre-existing CNS disease. Demographic, administrative, and neuroimaging data were extracted with 10% of charts independently reviewed by a staff Emergency Physician for inter-rater reliability. Results: 270 cases met study criteria. CT results were unavailable in 3, leaving 267 cases studied. The population demographics were: 49% percent female, average age 51 years old, 28% homeless, 59% arrived by police and/or ambulance. CT head results demonstrated 1 (0.4%) case with possible acute findings on CT. 108 (40%) had incidental findings (i.e. cerebral atrophy, small hypodensities), none of which impacted clinical management. Average time to physician assessment was 1 hour 58 minutes (sd 1:17) and time to CT head completion was 6 hours 50 minutes (sd 7:20) leaving an average of 4 hours 52 minutes awaiting these results. Ultimately 86% of patients were referred to a consultant of which 92% were to Psychiatry. Conclusion: This study of CT head scans for bizarre behavior ED presentations showed that the CT results did not change the clinical management of the patient. Furthermore, awaiting these results prolonged ED length of stay and delayed patient disposition. A prospective trial of a clinical decision tool for ordering CT head scans in these patients is warranted.