Risk Factors for Delirium During Acute and Subacute Stages of Various Disorders in Patients Admitted to Rehabilitation Units

OBJECTIVE: To assess the risk factors for delirium in patients admitted to a rehabilitation unit for acute or subacute neurological or musculoskeletal disorders. METHODS: We reviewed the medical records of 537 patients admitted to a rehabilitation unit and selected 398 patients in the acute or subacute stage of various neurological or musculoskeletal disorders. Among them, patients who had suffered from delirium were categorized into the delirium group (n=65), and the other patients were categorized into the non-delirium group (n=333). As potential risk factors for delirium, the patients' diagnosis, underlying disease, demographic data, hospital stay duration, surgery, and laboratory findings were reviewed, and the differences between the two groups with respect to independent risk factors were analyzed. RESULTS: The average age in the delirium group was higher; the hospital stay and pre-transfer periods were longer. A large proportion of the patients were admitted for musculoskeletal disorders, and many patients had diabetes mellitus, dementia, and depression as underlying diseases. Laboratory tests revealed increases in the white blood cells (WBC), glucose, blood urea nitrogen (BUN), total bilirubin, aspartate transaminase (AST), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels in the delirium group, while the hemoglobin, calcium, phosphorus, protein, albumin, and potassium levels were decreased. Depression, musculoskeletal disorders, traumatic brain injury, elevated WBC, BUN, AST, and CRP levels, and decreased potassium and phosphorus levels were identified as independent risk factors for delirium. CONCLUSION: Risk factors treatable before delirium onset were identified in rehabilitation patients in acute and subacute stages of various disorders. Early diagnosis and prevention of these risk factors could decrease delirium occurrence and increase rehabilitation effectiveness.