Reversible, narcotic-associated mental status impairment in patients with metastatic cancer

Pain and mental status were assessed in a series of 35 consecutive hospitalized patients with metastatic cancer receiving narcotics for pain that was difficult to control. Forty-five episodes of mental status impairment were detected in 27 of these patients. Fifteen patients had dose-related oversedation or organic brain syndrome. In only 4 could the narcotic dose be decreased without exacerbating the pain. Eleven patients had mental status impairment associated with factors other than the narcotic dose. These factors were: concurrent CNS-depressant drugs, presence of fever or infection, or changing from parental to average oral equianalgesic dose of narcotic. When these factors were corrected, mental function improved and remained stable despite resumption of the previous narcotic dose. Delirium occurred more frequently in patients over 65, while oversedation without delirium was more frequent in the younger group. For some patients with advanced metastatic cancer, pain relief and intact mental status cannot coexist. For others, correction of factors other than narcotics which can impair function can often lead to improved mental status without decreasing narcotic dose or decreasing the degree of pain control.