According to a new study published in The Oncologist, patients with advanced cancer who are diagnosed with delirium when turning up in emergency departments are more likely to be admitted to hospital and more likely to die earlier than patients without delirium. This shows the importance of accurately diagnosing delirium in advanced cancer patients, says lead author Ahmed Elsayem, MD, associate professor in the department of emergency medicine at the University of Texas MD Anderson Cancer Center in Houston, even though delirium can easily be missed in busy emergency departments.

In patients with advanced cancer, delirium can be caused by various different factors. “Advanced cancer itself is a major cause, and other problems such as medications or infection are triggers that can precipitate the full blown syndrome,” explains Dr. Elsayem. Previous studies have shown that delirium is associated with poor survival in advanced cancer patients being treated in intensive care units (ICUs) or receiving palliative care in hospices, but no one had investigated whether the same was true for those reporting to emergency departments.

“To the best our knowledge this is the first study to show the poor survival of advanced cancer patients in the emergency department setting,” says Dr. Elsayem.

This study follows on from an earlier study conducted by Dr. Elsayem and his colleagues in which they assessed the frequency of delirium in advanced cancer patients visiting the emergency department at MD Anderson. They tested for delirium using two separate questionnaires, classifying patients as suffering from delirium if at least one of the questionnaires gave a positive result.

Questioning 243 patients in total, they found that 44, or 18 percent, were suffering with delirium according to at least one of the questionnaires. In this current study, they investigated the proportion of these cancer patients with and without delirium that were subsequently admitted to hospital and ICUs, and recorded how long they lived after their visit to the emergency department. They also looked at whether possessing advanced directives, which specify the treatments a patient wants to receive if they are no longer able to make decisions for themselves, influenced the rates of hospitalization and survival.

They discovered that the majority of cancer patients with delirium were admitted to hospital (80 percent), whereas only 49 percent of those without delirium were admitted; patients with delirium were also much more likely to be admitted into the ICU. Advanced cancer patients with delirium were also likely to die earlier, surviving for a median time of between one and four months after their visit to the emergency department, compared with a median survival time of over 10 months for patients without delirium. Although around half of the patients had advanced directives, these did not seem to have any effect on the rates of hospitalization or survival.