Underlying pathologies and their associations with clinical features in terminal delirium of cancer patients

Delirium is a common complication in terminally ill cancer patients. Identification of underlying pathologies and prediction of clinical features may improve effective symptom alleviation. This study aims to clarify precipitating factors and their associations with clinical features of terminal delirium. Consecutive hospice inpatients who developed delirium were prospectively evaluated following a structured protocol. Among 237 patients followed until death, 245 episodes of delirium were identified in 213 patients. Precipitating factors for delirium were disclosed in 93% of the 153 cases in which investigations were completed. Mean number of etiologies was 1.8 +/- 1.1 per patient, and two or more factors were recognized in 52%. The main pathologies identified were hepatic failure, medications, prerenal azotemia, hyperosmolality, hypoxia, disseminated intravascular coagulation, organic damage to the central nervous system, infection, and hypercalcemia. Occurrence of hyperactive delirium and the requirement for symptomatic sedation significantly correlated with hepatic failure, opioids, and steroids, while dehydration-related pathologies were significantly associated with hypoactive delirium. Complete recovery was frequently achieved in cases with medication- and hypercalcemia-induced delirium, whereas a low remission rate was related to hepatic failure, dehydration, hypoxia, and disseminated intravascular coagulation. In conclusion, standard examinations can confirm factors potentially contributing to delirium and thereby predict the severity of agitation and clinical outcomes.