Head Computed Tomography Findings in Geriatric Emergency Department Patients with Delirium, Altered Mental Status, and Confusion: A Systematic Review.

BACKGROUND: Delirium, altered mental status or confusion among older adults are common presentations to the emergency department (ED). We aimed to report the proportion of older ED patients presenting with delirium who have acute abnormal findings on head imaging. We also assessed whether anticoagulation, neurological deficits, trauma or headache were associated with head imaging abnormalities in these patients. METHODS: A systematic review was performed using Ovid Medline, Embase, Clinicaltrials.gov, Web of Science, and Cochrane Central from conception to April 8th , 2021. Citations were included if they described patients aged 65 years or older who received neuroimaging at the time of ED assessment for delirium, confusion, or altered mental status. Screening, data extraction, and bias assessment were performed in duplicate. The estimated proportion of patients with abnormal neuroimaging and odds ratios for each predictor were calculated. RESULTS: The search strategy identified 3,014 unique citations, of which six studies reporting on 909 patients with confusion or altered mental status were included. None of the studies formally diagnosed delirium. Overall, the proportion of older ED patients with altered mental status or confusion were found to have an abnormal head CT was 15.6% (95% CI 7.3-26.2%). The prevalence of focal neurologic findings was 0.13 and for anticoagulation was 0.09 among the studies who reported them. The presence of a focal neurological deficit was associated with abnormal head CT (odds ratio [OR] 101.8; 95% CI 30.5-340.1). Anticoagulation was not associated with abnormal head CT (OR 1.2; 95% CI 0.4-3.3). No studies reported on the association between headache or trauma and abnormal neuroimaging. CONCLUSION: The proportion of abnormal findings on CT neuroimaging in older ED patients with altered mental status or confusion was 15.6%. The presence of a focal neurological deficit was a strong predictor for the presence of acute abnormality, whereas anticoagulation was not.