Prevalence of Delirium and Its Association with Risk Factors in Intensive Care Unit Patients

Objectives: Delirium is a common acute brain dysfunction in critically ill patients and is associated with poor short- and long-term outcomes, yet it often remains under-recognized. This study aimed to determine the prevalence of delirium in adult ICU patients and to examine its association with clinical and laboratory risk factors.
Methods: In this prospective observational study, we evaluated 60 consecutive adults (≥18 years) admitted to a tertiary ICU with a Richmond Agitation–Sedation Scale (RASS) score between −3 and +4. Sedation was assessed using RASS; delirium using the Confusion Assessment Method for the ICU (CAM-ICU) and the Delirium Rating Scale–Revised-98 (DRS-R-98); organ dysfunction using the Sequential Organ Failure Assessment (SOFA); and illness severity using APACHE II. Demographics, comorbidities, basic laboratory tests, and sedative and analgesic drug use were obtained from medical records.
Results: The mean age was 65±18 years, and 59.4% of the patients were male. Delirium was diagnosed by CAM-ICU in 28 patients (46.7%). Compared with non-delirious patients, those with delirium were older (70±15 vs. 60±19 years) and had higher DRS-R-98, C-reactive protein, APACHE II, and SOFA scores, as well as lower platelet count, Glasgow Coma Scale (GCS), and RASS scores (all p<0.05).
Conclusion: Delirium is frequent among ICU patients and is associated with advanced age, greater disease severity, organ dysfunction, deeper sedation, and adverse inflammatory and hematological profiles. The combined use of CAM-ICU and DRS-R-98 appears reliable for identifying delirium and monitoring its severity in the ICU.

Keywords: CAM-ICU, delirium, DRS-R-98, intensive care unit, risk factors