Delirium often is missed in overcrowded emergency departments, and diagnosing the condition in advanced cancer patients is especially important, according to a new study.

The report in The Oncologist explains why: Those patients diagnosed with delirium in the ED are more likely to be admitted to the hospital and are also more likely die earlier than patients who don’t exhibit signs of the condition.

Lead author Ahmed Elsayem, MD, of the University of Texas MD Anderson Cancer Center in Houston suggested that delirium can have a variety of causes in patients with advanced cancer. In addition to the cancer itself being a cause, medications and infection are other factors that can trigger delirium, Elsayem explained.

Previous research has linked delirium with poor survival in advanced cancer patients being treated in intensive care units (ICUs) or receiving palliative care in hospices. This study is touted as the first investigation of whether that outcome also is more likely for those patients presenting to the oncology ED.

This study follows a prior study in which Elsayem and his colleagues analyzed the frequency of delirium in advanced cancer patients at MD Anderson’s ED. Two separate questionnaires were employed to test for delirium, and 18% of 224 patients were classified as having it based on a positive result from at least one of the questionnaires.

For the current study, the researchers focused on how many of the cancer patients in the ED with and without delirium were admitted to hospitals and ICUs and how long they survived. Results indicate that 80% of cancer patients with delirium were admitted compared to 49% of those without. Only 2% of patients without delirium were admitted to the ICU, while admission rates ranged from 14% to 18% for those determined to have delirium.

In addition, advanced cancer patients with delirium were also likely to have shorter survival times, dying one to four months after their visit to the ED on average, compared with a median survival time of more than 10 months for patients without delirium, the report notes.  

Although about half of the patients with delirium had advanced directives, no link was found between those and rates of hospitalization or survival.

Elsayem pointed out that after prompt diagnosis, delirium in advanced cancer patients often can be resolved by stopping or modifying medication or by treating infections.