Development of Hypoactive Delirium in the Intensive Care Unit Is Associated with Poor Functional Outcomes

This study aimed to determine whether delirium subtypes are associated with the ability to ambulate and independence during hospital discharge.

This was a retrospective study. Patients were admitted to our ICU between August 2023 and July 2024 with the following inclusion criteria: 18 years of age or older, activities of daily living independence before admission, and no history of dementia, higher brain dysfunction, or psychiatric illness. Exclusion criteria were death, discharge within 48 h of admission to the ICU, central nervous system diseases (cerebrovascular disease, spinal cord injury, etc.) that directly affected functional prognosis, and severely ill patients with a Glasgow Coma Scale score of 8 or less, which made evaluation difficult. The final sample consisted of 83 participants (age 70 ± 15.8 years). The Intensive Care Delirium Screening Checklist (ICDSC) and delirium classification criteria of Meagher D et al. (2008) were used to detect hypoactive delirium. Patients were classified as independent (mRS ≤ 2) or assisted (mRS ≥ 3) on the modified Rankin Scale (mRS) at discharge and as ambulatory independent (Functional Ambulation Categories [FAC] ≥ 4) or assisted (FAC ≤ 3) on the (FAC). Age, body mass index, ICU mobility scale score, ICDSC score, and the presence of hypoactive delirium were compared between the two groups.To examine the factors associated with mRS and FAC, logistic regression analysis was performed using items that were significant in the univariate analysis as explanatory variables. The significance level was set at less than 5%.

Logistic regression analysis revealed a significant difference in FAC between patients with and without hypoactive delirium (odds ratio 0.0056, 95% confidence interval 0.0046-0.68) (p0.05). The mRS score showed a significant difference according to age (p0.05).

Patients with hypoactive delirium have difficulty walking independently at hospital discharge, suggesting that hypoactive delirium may contribute to a poor functional prognosis.

In this study, Hypoactive delirium was identified as a factor contributing to poor functional prognosis. It is necessary to detect hypoactivity delirium, which is often overlooked, using assessment scales such as the ICDSC, and to prevent and respond to delirium early in the intervention period.