1. CT Head Scans Yield No Acute
Findings and Increase ED
Length of Stay in Patients
Presenting with Bizarre Behavior
P Ng1 M McGowan1 B Steinhart1, 2
1
2
Department of Medicine, University of Toronto
Emergency Medicine, St. Michael’s Hospital

2. Impact of Obtaining CT Head in the ED among Bizarre Behaviour Patients
Context
• Psychiatric presentations represent a growing proportion of Emergency visits
• Collaborative Emergency Department – Psychiatric Emergency Services approach is to
“medically clear” (ensure there is no organic cause) stable patients, including blood work
and CT Head prior to transfer of care to Psychiatric Emergency Services (PES)
St. Michael’s Hospital, Toronto, ON
• Urban, academic, inner city, level-1 trauma centre (ED volume 72,000 in 2012)
~ 10% annual volume increase
~ 15 % sheltered and/or homeless
~ 20% mental illness and/or addiction
Problem and Issue
• Canadian and American Psychiatric Association recommend CT Head with disease
onset despite no studies demonstrating causality
• CT Head scans, most commonly used in the Emergency Department, pose a radiation
risk to the patient and may require the use of chemical sedation (medications) or
physical restraints to obtain quality neuroimaging
• Are CT Head scans necessary and what is the impact on clinical management and time
spent in the Emergency Department?

3. Impact of Obtaining CT Head in the ED among Bizarre Behaviour Patients
Measurement
• Single-site 5-year retrospective review (2007-12) of patients > 18 years of age, triaged
as “mental health – bizarre behaviour” with a CT Head scan while under the care of ED
• “Mental health – bizarre behavior” defined as any deviation from normal cognitive
behavior with no obvious external or structural cause
• Exclusion criteria: focal neurologic deficits on exam; alternative medical etiology for
bizarre behavior (i.e. delirium, trauma); and/or pre-existing CNS disease
• 10% of all charts were reviewed by a staff Emergency Physician for inter-rater reliability
Table 1. Clinical Administrative Time Metrics
Physician Initial Assessment (PIA) mean (SD)
1:22 + 1:10 hr
PIA to CT Result
mean (SD)
9:09 + 10:37 hr
Consult Request
n (%)
75 (90%)
Psychiatry
71 (95%)
Consultant Service
Internal Medicine
mean (SD)
PIA to Consult Request
Consult Request Prior to CT
n (%)
Result
Consult Attend Prior to CT Result n (%)
Home
Departure Destination
Admit
4 (5.3%)
3:19 + 3:51 hr
47 (57%)
43 (52%)
34 (41%)
49 (59%)

4. Impact of Obtaining CT Head in the ED among Bizarre Behaviour Patients
Contribution to Patient Safety & Quality Improvement
CT Head scans did not yield acute findings
•While there was no change in clinical management of the patient based on CT Head findings, it
did potentiate radiation exposure and delayed consultant evaluation, which in turn postpones
initiation of definitive management
Acquiring CT Head prolongs ED Length of Stay
•Prolonged length of stay contributes to Emergency Department crowding which increases patient
wait times and impairs the evaluation and treatment of patients waiting to be seen
Table 2. Impact on ED Length of Stay and Consult Attending
MD assessment to
consult attending
Total ED length of
stay
Waiting for CT result prior to
assessment
9:09 ± 10:37hr
(0:33-68:58)
23:02 ± 17:28hr
(1:09-97:59)
Patient seen before CT result
3:19 ± 7:42hr
(0:00-97:24)
18:14 ± 18:25hr
(0:45-166:30)
Partners for Knowledge Translation
•Multi-centre review underway with 4 urban, academic Toronto Emergency Departments
•Collaborations with Psychiatry, Neurology, and Medical Imaging are in place to look at evidenceinformed patient-centred process improvement