Rapid Response: To Scan or Not to Scan? The Utility of Noncontrast CT Head for Altered Mental Status

The aims of the study were the following: (1) to determine how often computed tomography (CT) scans of the head are obtained on rapid responses called for altered mental status (AMS), (2) to determine whether CT imaging of the head is required during all rapid responses called for AMS, (3) to determine which patients would benefit from CT scans of the head in this setting, (4) to note whether an adequate neurologic exam was documented, (5) to determine the cost of CT scans that did not change management, and (6) to examine the role of medications leading to AMS.

The study was a retrospective chart review at Abington Jefferson Hospital. Data collected included the age, sex, time of rapid response, clinical condition of the patient, whether an arterial blood gas and blood glucose were done, and whether a neurological exam was documented in the resident's rapid response team note. The patien's medications were also reviewed. Computed tomography scan findings as well as changes made in a patient's care as a result of the scan were recorded. Any findings that did not lead to a change in management were considered a "negative" scan.

Overall, 610 rapid responses were activated from January to August 2016. One hundred four (17.04%) of the total rapid responses were for AMS and 83 (79.8%) of these patients underwent noncontrast CT scan of the head. The mean (SD) age of the patients was 74.7 (13.6) years. A total of 56.6% were female. The most frequent clinical conditions documented at the time of rapid responses were noted as confused (33.7%, 28/83), either lethargic or unconscious (32.5%, 27/83), and concern for stroke (21.7%, 18/83). A total of 96.4% (80/83) of the CT scans done were negative for any acute changes. The three patients with positive scans (3/83) had a change in management as a result of the scans. If patients with symptoms concerning for stroke and unconscious patients are excluded, the total number of remaining patients is 56. Of these, zero patients had a positive scan. A total of 64.7% of the rapid response teams were activated either in the afternoon (31.3%) or at night (33.7%). A total of 33.7% had a complete neurological exam documented. A total of 66.2% were either incomplete (34.9%) or absent (31.3%). Sixty percent of the patients who had a CT head for AMS also had a blood sugar checked at bedside. Thirty-eight percent had an arterial blood gas. More than half the patients were taking one or more sedating medications (45/83, 57.8%). Most patients were not on anticoagulants (79.5%).

The findings of this study suggest that CT scan of the head is useful in older patients, patients with symptoms concerning for stroke, or cases of sudden onset of impaired consciousness. Noncontrast CT scans of the head are not useful for other presentations of AMS.