Incidence and Risk Factors for Delirium in Older Patients Following Intensive Care Unit Admission: A Prospective Observational Study.

Abstract

Both high prevalence and incidence rates of delirium occur frequently among patients aged 65 years or older in intensive care units (ICUs) and are accompanied by adverse outcomes. Because of lack of nursing staff resources and imperfect humanistic care, delirium is easily overlooked by both physicians and nurses in the ICU in Mainland China. This study aimed to explore the incidence rate of delirium and to determine the risk factors among critically ill older patients. A prospective observational study was conducted on patients aged 65 years and older who were admitted consecutively to two ICUs of a university-affiliated hospital in China. The Confusion Assessment Method for the Intensive Care Unit and the Richmond Agitation-Sedation Scale were used to assess delirium status twice daily. Patient demographic, laboratory, medical, therapeutic, and prognostic data were collected. One hundred fifteen patients were included as participants, with a median age of 70 years (range 65-93 years). Seventy-six (66.1%) patients presented with delirium. Half of the sample had a hypoactive subtype. Patients who developed delirium had a longer mean length of ICU stay, greater chance of physical restraints use, greater use of fentanyl, and poorer sleep quality. A logistic regression analysis revealed that poor sleep quality (OR = 10.74, 95% CI [1.59, 72.47]) and physical restraints (OR = 13.04, 95% CI [1.57, 107.94]) were significantly associated with delirium. Delirium is a common aggravation in older patients following ICU admission. The factors found in this study to be independently associated with delirium include poor sleep quality and physical restraints. Both critical care physicians and nurses should pay greater attention to the quality of the ICU stay experienced by their older patients.