In patients with terminal cancer, researchers have found that certain subtypes of delirium — specifically, hypoactive and “mixed” delirium — are a strong indicator that death will come soon, according to a new study published in Psychosomatic Medicine: Journal of Biobehavioral Medicine.
Delirium refers to confusion, altered awareness, or altered thoughts. It can result from many different illnesses, medications, and other causes.
For the study, the investigators analyzed the connection between delirium and survival time in 322 patients with terminal cancer entering palliative care.
Delirium was divided into three subtypes according to standard DSM-5 criteria: hyperactive delirium, in which patients exhibit increased motor activity, loss of control, and restlessness; hypoactive delirium, which is characterized by decreased activity, decreased speech, and reduced awareness; and “mixed delirium, in which patients exhibit fluctuating activity levels or show normal psychomotor activity.
“Terminally ill patients with the hypoactive or mixed subtypes of delirium showed a higher probability of imminent death, with even earlier mortality among younger patients,” said researcher Sung-Wan Kim, M.D., and colleagues of Chonnam National University Medical School Gwangju, Republic of Korea.
About 30 percent of patients were diagnosed with delirium upon entering palliative care. Of these, the delirium subtype was hyperactive in about 15 percent of patients, hypoactive in 34 percent, and mixed in 51 percent.
Survival time after entering palliative care was shorter for patients with delirium: median 17 days, compared to 28 days for those without delirium. However, the difference was significant only for patients with hypoactive or mixed delirium, with median survival times of 14 and 15 days, respectively.
After adjusting for other potential factors, the findings remained the same. Although delirium was more common in older patients, the effects on time to death were actually stronger in younger patients. This is consistent with earlier research findings suggesting shorter survival times in younger patients with delirium. For patients with hyperactive delirium, survival time was similar to patients without delirium.
Why are different delirium subtypes linked to differing survival times? The researchers say it may have to do with differences in the underlying causes of and treatment responses. For example, hyperactive delirium is commonly related to reversible causes, such as medication side effects.
“In contrast, hypoactive delirium is generally related to hypoxia [decreased oxygen levels], metabolic disturbances, and multi-organ failure,” Kim said. “Therefore, hypoactive delirium could be associated with a higher mortality rate than hyperactive delirium.”
“Also, the earlier mortality in younger patients overturns a conventional assumption for survival prediction of delirium. Although delirium was more prevalent in older patients, as known, the irony is that delirium predicted shorter survival in younger patients,” Kim said.
Accurate predictions of survival time in terminally ill patients are important for many reasons; “in terms of ensuring good clinical decision making, developing care strategies, and preparing for the end of life in a dignified manner.”
“Thus, the present findings could facilitate more precise predictions of survival, allowing families to prepare for the patient’s death,” concluded the researchers.
Source: Wolters Kluwer Health