Delirium in advanced cancer patients often goes undetected in the emergency department

A new study indicates that delirium is relatively frequent and underdiagnosed by physicians in patients with advanced cancer visiting the emergency department. Delirium was similarly common among older and younger patients, which suggests that in the setting of advanced cancer, all patients should be considered at higher risk for delirium. The findings are published early online in Cancer, a peer-reviewed journal of the American Cancer Society.

Delirium is the most common neuro-psychiatric syndrome in patients with advanced cancer, but most delirium studies in cancer patients have been limited to the palliative care setting, while those in the emergency department setting have been limited to elderly patients. To investigate the frequency of delirium among patients with cancer presenting to the emergency department, a team led by Knox Todd, MD, MPH, of The University of Texas MD Anderson Cancer Center in Houston, assessed a random sample of English-speaking advanced cancer patients who presented to the emergency department. All patients were assessed with two methods: the Confusion Assessment Method (CAM) to screen for delirium and the Memorial Delirium Assessment Scale (MDAS) to measure delirium severity (mild <15, moderate 16-22, and severe >23).

Of 243 enrolled patients with an age range of 19 to 89 years, 22 (9 percent) had CAM-positive delirium and a median MDAS score of 14. Among CAM-positive patients, delirium was mild in 18 (82 percent) and moderate in four (18 percent) according to the MDAS.

Of 99 patients aged 65 years and older, ten (10 percent) had CAM-positive delirium, compared with 12 (8 percent) of 144 patients younger than 65 years. When emergency department physicians were asked whether their patients were delirious, they failed to detect delirium in nine (41 percent) of CAM-positive delirious patients.

"We found evidence of delirium in one of every ten patients with advanced cancer who are treated in the emergency department. Given that we could only study patients who were able to give consent to enter our study, even ten percent is likely to be a low estimate," said Dr. Todd. "We also identified many psychoactive medications that could have contributed to delirium, and sharing this information with treating oncologists may help them avoid such complications in the next patient they treat." This is an example of the importance of the emergency department as a setting for monitoring the quality of cancer-related care and its potential role in preventing complications of cancer treatment.