The most common neuropsychiatric symptom in patients with advanced cancer is delirium1; however, it frequently goes undetected and untreated. Most studies of delirium to date have focused on palliative care settings. Within inpatient oncology units, up to 40% of patients may experience delirium,2 and more than 80% of patients at the end of life exhibit delirium in their final days.3,4
The emergency department (ED) is a critically important assessment venue within the cancer trajectory. Patients evaluated in this setting are often those with advanced disease and high symptom burden. A recent study undertaken at MD Anderson Cancer Center in Houston, Texas sought to evaluate the incidence of delirium in their ED.5 Approximately 2,000 patients were screened for delirium using both the 4-item Confusion Assessment Method (CAM) instrument and the 10-item Memorial Delirium Assessment Scale (MDAS).6,7
Patients who were screened positive for delirium using the CAM instrument were similarly identified as such with the MDAS tool. However, the MDAS seemed more sensitive. There were 22 instances where patients had negative delirium results with CAM but were rated positive for delirium with the MDAS. Most of the delirium scores were indicative of mild delirium, and medications were the major contributing factor in 91% of cases. Age was not a distinguishing factor. ED physicians missed diagnosing delirium in 41% of patients despite having received education about the symptoms and characteristics prior to the study’s implementation. Hence, there are numerous implications for clinical practice based on these results.
Within the cancer patient’s point of entry into the health care system—the ED, clinic, or direct admit to the inpatient unit—clinicians should screen for delirium as an element of symptom distress. Undertaking a medication inventory, especially in the context of polypharmacy, is critical not only for the potential identification of altered cognition, but also for other pharmacologic indices of symptom distress related to drug-drug interactions and altered pharmacokinetics. Medication adjustment often works to address delirium intensity and prevalence especially if identified early. Other etiologic factors to consider include brain metastases, fever and infection (especially in the elderly), electrolyte imbalance, and some chemotherapies.8
Clinicians must be cognizant of the continuum of delirium’s presentation. With mild delirium, patients may be aware of subtle compromise and answer questions with simple yes or no responses to disguise their altered cognition. The clinical scenario of extreme agitation, not recognizing loved ones, and disorientation to place and time are late signs of delirium that has been evolving for some time.8 Lastly, while the MD Anderson researchers did not include this variable in their study, families are key historians in the identification of delirium. The timing and pattern of cognitive changes as well as examples of such are key determinants of a delirium diagnosis that can be provided by the patient’s loved ones.
Delirium is an under-recognized yet important element of symptom distress. By increasing awareness of its presentation, diagnosis, and early treatment, hospital admissions may be reduced, length of stay minimized, and quality of both patients’ and families’ lives enhanced.
1. Mehta RD, Roth AJ. Psychiatric considerations in the oncology setting. CA Cancer J Clin. 2015;65:300-14.
2. Braiteh F, El Osta B, Palmer JL, et al. Characteristics, findings, and outcomes of palliative care inpatient consultations at a comprehensive cancer center. J Palliat Med. 2007;10:948-55.
3. Bush SH, Leonard MM, Agar M, et al. End-of-life delirium: Issues regarding recognition, optimal management, and the role of sedation in the dying phase. J Pain Symptom Man. 2014;48:215-30.
4. Lawlor PG, Gagnon B, Mancini IL, et al. Occurrence, causes, and outcome of delirium in patients with advanced cancer: A prospective study. Arch Intern Med. 2000;160:786-94.
5. Elsayem AF, Bruera E, Valentine AD, et al. Delirium frequency among advanced cancer patients presenting to an emergency department: A prospective, randomized observational study. Cancer. 2016;122:2918-24.
6. Inouye SK, van Dyck CH, Alessi CA, et al. Clarifying confusion: The Confusion Assessment Method: A new method for detection for delirium. Ann Intern Med. 1990;113:941-8.
7. Breitbart W, Rosenfeld B, Roth A, et al. The Memorial Delirium Assessment Scale. J Pain Symptom Manage. 1997;13:128-37.
8. Boyle DA, Abernathy G, Baker L, Wall AC. End of life confusion in the patient with cancer. Oncol Nurs Forum. 1998;25:1335-43.