Abstract Title The Impact of Altered Mental Status on Intensive Care Unit Outcomes: A Retrospective Cohort Study

Background Altered Mental Status (AMS) ranges from confusion to coma and is frequently encountered in patients admitted to the Intensive Care Unit (ICU). Etiologies include metabolic disturbances, neurological insults, and systemic illnesses. The precise impact of AMS on in-ICU mortality remains an area of ongoing research, necessitating comprehensive evaluation and elucidation. The objective of our study was to identify significant patterns and outcomes associated with the presence of AMS upon initial Emergency Department (ED) presentation to better inform ICU management and enhance patient care.

Methods A retrospective cohort study was conducted using patient data from the Northwell Health network, focusing on adult ICU admissions between July 1, 2022, and July 1, 2023. The study included 21,900 unique patients. The primary variables were AMS presence and in-ICU mortality, both recorded as binary outcomes. Descriptive statistics were analyzed for patient demographics and clinical characteristics, including gender distribution and racial composition. The association between AMS and in-ICU mortality was tested using a Chi-square test of independence, with statistical significance set at p < 0.05. The impact of AMS on ICU and hospital stays, treatments (steroids and vasopressors), and acute renal failure incidence was further assessed using Chi-square tests with relative risks and 95% confidence intervals calculated.

Results Patients with AMS experienced longer ICU and hospital stays, averaging 144.3 hours in the ICU and 13.6 days in the hospital compared to 111.3 hours and 10.1 days for those without AMS, respectively. Patients with AMS were more likely to receive steroids, χ2(1, N = 21,900) = 40.0, p < .001, RR = 1.13, 95% CI 1.08, 1.18. They were also more likely to be on vasopressors, χ2(1, N = 21,900) = 98.2, p < .001, RR = 1.24, 95% CI 1.18, 1.31, and to develop acute renal failure, χ2(1, N = 21,900) = 53.1, p < .001, RR = 1.15, 95% CI 1.10, 1.20. The Chi-square test demonstrated a significant association between AMS and in-ICU mortality, χ2(1, N = 21,900) = 111, p < .001, RR = 1.13, 95% CI 1.10, 1.17.

Conclusion AMS presence was significantly associated with longer ICU and hospital length of stay, more frequent need for vasopressors and steroids, a higher occurrence of acute renal failure, and increased in-ICU mortality rates. These findings underline the importance of AMS as a prognostic indicator in ICU settings and stress the need for increased awareness and proactive management of AMS to potentially improve patient outcomes in the ICU.