Factors Related to the Severity of Delirium in the Elderly Patients With Infection

Objective: Delirium is a common neuropsychiatric syndrome in the elderly characterized by concurrent impairments in cognition and behavior. Infection is one of the most important risk factors for delirium. The objective of this study is to elaborate the factors related to the severity of delirium in the elderly patients with infection. Method: An observational study on the relationship of several clinical parameters and the severity of delirium in elderly patients (more than 60 years) with infection was conducted at Geriatric Inpatient Ward, Sanglah Hospital. Delirium was defined by the Memorial Delirium Assessment Scale (MDAS). Charlson Age Comorbidity Index (CACI) scores were calculated as proposed by Charlson et al. Infection was confirmed by clinical, laboratory, and radiographic findings. Results: During 3 months, there were 60 elderly patients (35 men and 25 women) who were hospitalized with infection and delirium. In all, 33 (55.0%), 16 (26.7%), and 11 (18.3%) patients had pneumonia, urinary tract infection, and other infections, respectively, and 44 out of 60 (73.3%) patients had sepsis. There was no significant difference found in MDAS score between male and female patients and among different types of infection, but patients with sepsis had higher MDAS score significantly compared with patients without sepsis (19.48 ± 3.72 vs. 15.88 ± 2.82; p < .001). This study revealed that of several clinical parameters, only CACI (R = .533; p < .001), blood urea nitrogen (BUN; R = .230; p = .040), and interleukin 6 (IL-6) levels (R = .499; p < .001) were correlated with MDAS score significantly. By multiple linear regression test, CACI, IL-6, and sepsis have significant role, meanwhile, BUN has no role, on the severity of delirium. Conclusions: The CACI score, IL-6 levels, and sepsis have strong relationship with the severity of delirium, but BUN only has weak role in the severity of delirium in the elderly patients with infection.