Incidence, prevalence, risk factors and outcome of delirium in the intensive care unit of a tertiary care hospital

Context: Delirium is an acute fluctuating disorder. Impairment in attention and awareness is considered a core symptom. Data from the west suggests that up to 80% of ventilated patients have delirium. Aims: The aim of this study was to evaluate the incidence, prevalence, risk factors, and outcome of delirium in the intensive care unit (ICU) of a tertiary care hospital. Settings and Design: The study was carried out in various ICUs of a multidisciplinary tertiary care hospital after approval from the Institutional Ethics Committee. Written informed consent was obtained from the patients or family members of the patients before enrolling in the study. Subjects and Methods: Consecutive patients aged 16 years or more admitted to the ICUs were recruited for the study. Patients with bilateral deafness and blindness, neurosurgical and neurological cases, and patients or relatives refusing consent were excluded. All the patients were assessed between 9 am and 5 pm daily on the Richmond Agitation and Sedation Scale (RASS) to assess the level of sedation and agitation. The patients found to be arousable (-3 to + 4) were screened using the Confusion Assessment Method for ICU (CAM-ICU) for the presence of delirium. Those patients who screened positive for delirium on CAM-ICU were further assessed by the psychiatrist for the diagnosis of delirium as per the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision ( DSM-IV-TR) diagnostic criteria. All the enrolled patients were administered an etiological checklist specifically designed for the study. The patients were followed until the point of discharge from ICU or death. Statistical Analysis Used: Data analysis was performed using Epidata Analysis version 2.2.2 and Epilnfo 3.5.4 software. Results: Out of 109 patients, 18 (16.5%) patients had delirium within 24 h of admission in ICU, and 36 (33%) developed delirium after 24 h of ICU stay. Conclusions: Thus a total of 49.5% of patients developed delirium during ICU stay. History of delirium in the past, the use of invasive ventilation, and hypocalcemia were significantly more in delirious patients as compared to nondelirious patients. The mean stay of delirious patients in ICU was significantly more. Restraints were used more in delirious patients, and the difference was statistically significant.