NEW YORK--About 30% of the cancer patients he is asked to evaluate for depression turn out to have delirium, said Memorial Sloan-Kettering psychiatrist William S. Breitbart, MD, at a conference sponsored by Cancer Care, Inc.
"That's because some patients with delirium are hypoalert, lethargic as opposed to agitated. They're lying in bed curled up in the fetal position, looking sad, but the patients' mental status has not been evaluated," he said. "No one has asked the patient--Do you know where you are? Do you know the name of this place? Do you know what room you're in?"
Such patients may have trouble talking and naming things, or may have frank aphasia. They may hallucinate. "The disturbance often develops over a short period of time, and the symptoms may fluctuate," Dr. Breitbart pointed out.
The delirium usually exists in the context of some physical cause, and is common in cancer patients who are in pain and receiving opiates. He pointed out that most patients on stable doses of oral opioids have completely intact mental function.
"They're oriented, alert, and able to think clearly. But uncontrolled pain can interfere dramatically with the ability to concentrate," he said. "Patients are more likely to get confused and disoriented during periods of rapid dose escalation, whether orally or intravenously."
Intravenous or subcutaneous infusions are often used to get rapid control over exacerbation of pain in the hospital, and sometimes in the home setting. "So it's really during these periods of rapid escalation of dose that oncologists see delirium," he said.