Prevalence and risk factors of delirium in the intensive care unit: An observational study

Background: Several risk factors, such as age, alcohol abuse, dementia, and severe illness, can contribute to the development of delirium. However, limited information is available in the literature regarding the risk of delirium among surgical, trauma, neurological, and medical intensive care patients. Aims and objectives: To describe the prevalence of risk factors associated with delirium in intensive care units. Design: This study used an observational design. Methods: We enrolled 165 patients hospitalized in two intensive care units in Italy. Patients were first evaluated using the Prediction of Delirium model and were subsequently evaluated using the Intensive Care Delirium Screening Checklist; evaluation lasted a maximum of 5 days for each admitted patient after sedation. A logistic regression model was used to identify the prevalence and risk factors of delirium. Results: The average age of the patients was 57.6 (SD = 18.3) years, and the patients were predominantly male (65.0%). The majority of patients had been subjected to trauma (38.8%); 37.6% had undergone general surgical interventions, and 23.6% had undergone medical interventions. Delirium occurred in 55.8% of the 165 patients. The risk of delirium was independently associated with coma (odds ratio = 10.6; 95% confidence interval, 3.08-39.9) and the Acute Physiology and Chronic Health Evaluation II score (odds ratio = 4.27; 95% confidence interval, 1.58-11.53). Conclusions: This study confirmed that coma and the Acute Physiology and Chronic Health Evaluation II score were non-modifiable risk factors for delirium. Further studies could categorize the different types of coma. Proper delirium management could limit the impact on the recovery of these patients, their autonomy, and their reintegration into the social and professional world. Relevance to clinical practice: Delirium increases intensive care unit and hospital length of stay. Early identification and risk factor assessment by critical care nurses are considered the key factors in the treatment of delirium.