Delirium During Acute Events in Nursing Home Patients

Abstract

Objectives: Assess the frequency of delirium during any acute event, its risk factors, and the duration of delirium in nursing home patients.

Design: Prospective 2-month follow-up study.

Setting and participants: 145 nursing home patients living in 3 Norwegian nursing homes.

Methods: At baseline, known risk factors for delirium were obtained from medical records. During any acute events where the nurses decided that a physician had to be alerted, the Confusion Assessment Method was used to identify delirium on days 1, 2, 4, and 6 and thereafter weekly if delirium was present on day 6. The precipitating cause of delirium was registered based on diagnostics performed and treatment given.

Results: One or more acute events occurred in 57 patients, and 34 (60%) of these patients developed delirium. In 91% of the patients with delirium, the delirium was present when the physician was alerted about the acute change. Delirium lasted for more than 1 week in 15 of the 34 patients. In 18 of the 34 patients with delirium, an infection was its precipitating factor. Regular use of benzodiazepines and a diagnosis of vascular dementia were significantly associated with delirium in the logistic regression model adjusted for age, number of drugs, and comorbidity [adjusted odds ratio (95% confidence interval) 3.75 (1.44-9.74) and 5.59 (1.53-20.43), respectively].

Conclusions and implications: Acute events and illness were common in nursing home patients, and in our study, 60% had delirium associated with the event. In 9 of 10 patients, the delirium was present when the physician was alerted about the acute change, and infection was the most frequent cause of the delirium. Regular use of benzodiazepines and a diagnosis of vascular dementia were independent predisposing factors for delirium.

Keywords: Delirium; acute disease; benzodiazepines; nursing home.