Delirium in critical care: a study of incidence, prevalence, and associated factors in the tertiary care hospital of older Thai adults.

Objectives: Delirium is a common condition in older adults which can have devastating outcomes. The studies about delirium in intensive care units (ICU) are relatively rare compared to studies in the non-ICU setting. This study aimed to study the prevalence, incidence, and risk factors of delirium among older Thai adults in ICU.

Method: Participants were older patients who were admitted to the ICU of Srinagarind Medical School, KhonKaen, Thailand from May 2013 to August 2014. Baseline characteristics were collected. Delirium was rated by trained clinical researchers using the Confusion Assessment Method for the ICU (CAM-ICU). Demographic data were analyzed using descriptive statistics. Regression analyses were used to analyze the outcomes.

Results: Delirium occurred in 44 of 99 patients (44.4%) with an incidence rate of 22.2% (22/99). The prevalence of delirium in mechanically ventilated patients was 62.5% (30/48). The majority of the patients had delirium within five days of ICU admission. Seven independent predisposing factors were identified using bivariate regressions: age, functional status, disease severity, having pneumonia, cognitive impairment, depression, or previous stroke. Numbers of additional drugs, bed changes, physical restraints, sleep deprivation, use of bladder catheters, and patients with mechanical ventilators were independent precipitating factors. For multivariate regressions, previous stroke, multiple bed changes, and physical restraints were the significant factors.

Conclusion: The prevalence and incidence of delirium of older adults in the ICU setting in this study was high and comparable to prior studies. There are several significant risk factors associated with delirium which could be modified. These factors should be considered when designing effective preventive strategies of delirium.