Background: Delirium is often a distressing symptom for both patients and their families, and its prevention is important. The primary aim of this study was to clarify the effects of partial opioid substitution and hydration on the occurrence of agitated delirium in the final stage of cancer.
Methods: An historical control study on consecutive terminally ill cancer patients admitted to a palliative care unit (164 in 1996-1997 and 120 in 2000-2001). In 2000-2001, we actively performed hydration and partial opioid substitution from morphine with fentanyl on individual grounds. Two independent raters evaluated the degree of agitation and cognitive impairment during the final week, using the Memorial Delirium Assessment Scale, the Agitation Distress Scale, the Communication Capacity Scale, and a consciousness scale.
Results: Compared to 1996-1997, in 2000-2001, the use of artificial hydration (33% to 44%, p = 0.053) and opioid rotation (3.0% to 41%, p < 0.01) increased, while there were no statistically significant differences in hydration volume, the mean dose, and the high-dose requirements of morphine. The prevalence of agitated delirium, the agitation score, the percentage of patients achieving clear-complex communication, and the percentage of patients who maintained clear consciousness did not significantly change.
Conclusions: Partial opioid substitution with fentanyl and moderate levels of hydration had no significant preventive effects on the occurrence of agitated delirium in the last week on a mass level. We should explore new strategies to prevent agitated delirium that are practically available in Japan.