CLEVELANDDelirium, although common in patients with
advanced cancer, is poorly understood, Donna S. Zhukovsky, MD, said
at a conference on palliative medicine held at the Cleveland Clinic
Foundation. Properly identifying delirium can be difficult, and the
literature shows that it frequently goes unrecognized by physicians
and nurses, said Dr. Zhukovsky, of the Cleveland Clinic
Foundations Harry R. Horvitz Center for Palliative Medicine.
Delirium is characterized by a disturbance in consciousness and a
change in cognition that develop in a brief period of time, she said.
It tends to fluctuate over the course of the day, so that patients
with delirium may have periods of normality interspersed with delirium.
In cancer patients, treatment side effects of drugs or radiation can
cause delirium. Other possible causes include metabolic
encephalopathies, infection, anemias, nutritional deficiencies, and
Although impaired thinking and memory are common to both delirium and
dementia, patients with dementia tend to have a more stable course,
Dr. Zhukovsky said. They have a more gradual onset of cognitive
impairment, and their impairment does not fluctuate throughout the
day. They usually have no clouding of consciousness and deteriorate
over longer periods of time.
Delirium is present in 8% to 85% of cancer patients, according to the
literature, with the variation explained by different study
populations and assessment tools. Delirium is found in 20% to
40% of people with advanced cancer, Dr. Zhukovsky said.
Delirium is extremely common preceding death, which raises
implications for obtaining patient consent to medical treatment. In
one study, patients developed cognitive failure, on average, 16 days
prior to death. The cause of the delirium could not be identified in
56% of these patients (Bruera E et al: J Pain Symptom Manage
When treating delirium, the clinician must recognize that the
situation is often related to multiple factors, including the disease
process, medical comorbidities, and medications, Dr. Zhukovsky said.
There are three delirium subtypes: hypoalert, hyperalert, and mixed.
These different subtypes have different prognoses, with hyperalert
having the best prognosis in terms of mortality, she said.
Patients with hyperalert (or hyperactive) delirium are agitated,
often with hallucinations and delusions. This is the most common type
of delirium, she said, and it is often quickly identified because of
the patients behavioral problems.
With hypoalert (or lethargic) delirium, patients are sleepy and
withdrawn. Hypoalert delirium is frequently undiagnosed or
misdiagnosed as depression. People with the hypoalert form are
often not recognized because they are not behavioral problems and
therefore are not treated, Dr. Zhukovsky said.
People with delirium may have periods of normal cognition. This
further complicates the diagnosis. In the Bruera study, cognitive
failure identified by the Mini-Mental Status Exam (see box) was
overlooked by the physician on the same day in 23% of cases and by
the nurse in 20% of cases.
Assessment Tools for Delirium
The Mini-Mental Status Examination (MMSE) is the gold
Zhukovsky said at the conference on palliative care. In addition, the
Many other tools exist for the assessment of delirium, each with its
She recommended the study of Smith et al for a look at more than 20
Treatment for delirium includes adding orienting devices to the
environment, such as clocks, calendars, and nightlights, she said.
However, the mainstay of treatment is dopamine-blocking agents such
as haloperidol, while correcting the contributing causes whenever possible.