Unique presentation of delirium after stem cell transplantation

In the first study of its kind, researchers say half of patients undergoing stem cell transplantation exhibit signs of delirium, but the warning signs are subtler and can be easily missed by clinicians. The study, which appears in the February 15, 2005 issue of CANCER, a peer-reviewed journal of the American Cancer Society, says the level of distress, fatigue, and pain are associated with the severity of delirium.

Delirium is a temporary, acute change in a patient’s level of consciousness and cognition or perception that is caused by a medical condition. Classically, clinicians identify delirium by the presence of hallucinations, delusions, agitation, and disorientation. However, delirium appears to present itself in two prognostic categories: transient with less clinical significance and prolonged with greater clinical significance. Delirium is associated with a higher risk of falls, wound infections, and aspiration pneumonia. In cancer patients, delirium is further associated with increased risk of death during hospitalization and within five years of follow-up. While treatable with medications and appropriate care, delirium is underdiagnosed and undertreated, which can result in poor outcomes, patient and caregiver distress, and over-utilization of healthcare resources.

In order to improve clinical recognition of delirium in patients undergoing hematopoietic stem cell treatment (HSCT), Jesse R. Fann, M.D., M.P.H. of the University of Washington’s Department of Psychiatry and Behavioral Sciences and Fred Hutchinson Cancer Research Center’s Division of Clinical Research and his colleagues followed 90 patients from before transplant to 30 days post-transplant and described the symptoms and time course as well as risk factors associated with delirium.

The authors found 50 percent of patients had delirium episodes, which could be categorized into three distinct clusters of symptoms: 1) psychotic and behavioral problems, 2) cognitive impairment, and 3) disturbance of mood and consciousness. Early symptoms began about four days prior to the start of the episode and lasted an average of 10 days, peaking at the end of the second week after transplantation. These symptoms included hypoactive behavior, sleep-wake cycle disturbance, and cognitive impairment. Simultaneous complaints of emotional distress, fatigue, and pain were strongly associated with delirium occurrence.

This study demonstrates that clinicians cannot rely on classic presentations such as hallucinations and agitation to recognize delirium in this patient population. Instead, the authors conclude, “more subtle symptoms of hypoactive psychomotor behavior, altered sleep-wake cycle, and impaired attention and working memory should be early indicators for increased monitoring and identification of possible causes of delirium.”