Computed tomography scanning and delirium in elder patients

Objective: 1) To examine the ordering of head CT scans in elder patients with delirium and cognitive impairment; and 2) to report CT scan findings associated with these conditions. Methods: This was a 2-part study. Part 1 was a prospective, observational study of 560 adults >70 years of age evaluated at 3 separate EDs using a 200-hour stratified sampling process at each ED. During Part 1, the frequencies of specific findings (i.e., delirium, impaired consciousness, and impaired cognition) and CT scan rates for these groups were determined. Part 2 was a retrospective analysis of CT scan reports and medical records (n = 279) for patients >70 years of age in the prospective sample (n = 79) and from a sample (n = 200) of CT scans obtained at a fourth ED. Part 2 examined clinical findings detected in the ED to determine those factors that were associated with acute findings on CT scan. Results: Part 1: There were 333 (59.4%) patients prospectively classified as having impaired cognition, impaired consciousness, or delirium; 79 (23.7%) of these patients had a head CT scan. Of these 3 groups, delirious patients were more frequently scanned (p < 0.001). Part 2: Of 279 CT scans, 42 (15.0%) were positive for an acute condition (hemorrhage, hematoma, space-occupying lesion, infarct). Of 42 positive scans, 40 (95.1%) were found in the 102 (36.6%) patients with either impaired consciousness or a new focal neurologic finding detected in the ED. Conclusions: Considerable variability in ED CT scan ordering exists for elder patients with neurologic findings, impaired consciousness and/or new focal neurologic signs are associated with acute findings on CT scan in elder patients. Acute CT abnormalities are uncommon in elder ED patients with other neurologic findings. Additional prospective evaluation is warranted prior to guideline development for CT scans in this patient population.