Background: Delirium is a well know post-operative complication that has been shown to increase mortality, length of stay, and post-operative complications. Despite extensive study, there is limited treatment for delirium once it occurs. Emphasis on preventing delirium and identifying patients at risk is an important part of reducing its impact on the individual and the health system. In attempt to identify patients at risk for delirium, our hospital utilizes the Mini-Cog cognitive screening tool in the pre-operative clinic. Starting in 2016, our hospital began conducting the Confusion Assessment Method (CAM) on all adult inpatients.
Methods: The medical records of 316 patients seen in the pre-operative clinic were reviewed manually. We evaluated patients for demographic information, discharge disposition, and scoring for various perioperative screening tools, including Mini-Cog, Revised Cardiac Risk Index, and CAM. Inclusion criteria included any adult over age 18 seen in the pre-operative clinic. A positive delirium screen was defined as any positive CAM during the admission. Exclusion criteria included surgery cancellation, absent Mini-Cog score, or lack of recorded CAM score during the admission. Outcomes were compared using a paired t-test, comparing low Mini-Cog and high Mini-Cog as well as CAM positive and CAM negative.
Results: Of the 316 patients initially enrolled, 154 patients completed pre-admission Mini-Cog screening, had documented postoperative CAM scores, and were discharged after their procedures were completed. The average age of patients enrolled was 73.8 years. 52 (19.7%) patients had a Mini-Cog score ≤2, which has been shown to indicate probable cognitive impairment. Of the 154 patients with recorded CAM scores, 4 (2.6%) had a positive screen during their admission. The average LOS was 3.02 ± 12.02 days. There was no significant difference in patient disposition destination based upon Mini-Cog score. There was no significant difference between LOS with Mini-Cog less than or equal to 2.
Conclusions: The role of the hospitalist in managing post-operative delirium is in the pre-operative setting and in co-management and consultation post-operatively. Identifying patients at risk for delirium is challenging. Our analysis of Mini-Cog score and CAM results post-operatively did not show a correlation between high risk Mini-Cog and increased occurrence of positive CAM. This may reflect the multifactorial nature of perioperative care, as anesthesiologists were notified of positive Mini-Cog scoring and encouraged to avoid high risk medication use, in response. Alternatively, the Mini-Cog may not an adequate tool to identify at risk patients in this population. The patients included in this study underwent elective surgery and generally were physiologically optimized prior to surgery. The presence of dementia or other preoperative cognitive disorders is a well described risk factor for delirium; therefore, the Mini-Cog may still be a valuable tool in identifying patients would potentially benefit from further optimization. Identification of such conditions and appropriate optimization would benefit all patients undergoing the physiologic stress associated with hospitalization that can precipitate delirium.