Management of Delirium in Palliative Care: a Review

Because no rigorously validated, simple yet accurate continuous delirium assessment instrument exists, we developed the Nursing Delirium Screening Scale (Nu-DESC). The Nu-DESC is an observational five-item scale that can be completed quickly. To test the validity of the Nu-DESC, 146 consecutive hospitalized patients from a prospective cohort study were continuously assessed for delirium symptoms by bedside nurses using the Nu-DESC. Psychometric properties of Nu-DESC screening were established using 59 blinded Confusion Assessment Method (CAM) ratings made by research nurses and psychiatrists. DSM-IV criteria and the Memorial Delirium Assessment Scale (MDAS) were rated along with CAM assessments. Analysis of these data showed that the Nu-DESC is psychometrically valid and has a sensitivity and specificity of 85.7% and 86.8%, respectively. These values are comparable to those of the MDAS, a longer instrument. Nu-DESC and DSM-IV sensitivities were similar. The Nu-DESC appears to be well-suited for widespread clinical use in busy oncology inpatient settings and shows promise as a research instrument.

Deficits in cholinergic function have been postulated to cause delirium and cognitive decline. This review examines current understanding of the cholinergic deficiency hypothesis in delirium by synthesizing evidence on potential pathophysiological pathways. Acetylcholine synthesis involves various precursors, enzymes, and receptors, and dysfunction in these components can lead to delirium. Insults to the brain, like ischemia and immunological stressors, can precipitously alter acetylcholine levels. Imbalances between cholinergic and other neurotransmitter pathways may result in delirium. Furthermore, genetic, enzymatic, and immunological overlaps exist between delirium and dementia related to the cholinergic pathway. Important areas for future research include identifying biomarkers, determining genetic contributions, and evaluating response to cholinergic drugs in delirium. Understanding how the cholinergic pathway relates to delirium may yield innovative approaches in the diagnosis, prevention, and treatment of this common, costly, and morbid condition.

To demonstrate the feasibility of a placebo-controlled trial of antipsychotics for delirium in the intensive care unit and to test the hypothesis that antipsychotics would improve days alive without delirium or coma. Randomized, double-blind, placebo-controlled trial. Six tertiary care medical centers in the US. One hundred one mechanically ventilated medical and surgical intensive care unit patients. Patients were randomly assigned to receive haloperidol or ziprasidone or placebo every 6 hrs for up to 14 days. Twice each day, frequency of study drug administration was adjusted according to delirium status, level of sedation, and side effects. The primary end point was the number of days patients were alive without delirium or coma. During the 21-day study period, patients in the haloperidol group spent a similar number days alive without delirium or coma (median [interquartile range], 14.0 [6.0-18.0] days) as did patients in the ziprasidone (15.0 [9.1-18.0] days) and placebo groups (12.5 [1.2-17.2] days; p = 0.66). No differences were found in secondary clinical outcomes, including ventilator-free days (p = .25), hospital length of stay (p = .68), and mortality (p = .81). Ten (29%) patients in the haloperidol group reported symptoms consistent with akathisia, compared with six (20%) patients in the ziprasidone group and seven (19%) patients in the placebo group (p = .60), and a global measure of extrapyramidal symptoms was similar between treatment groups (p = .46). A randomized, placebo-controlled trial of antipsychotics for delirium in mechanically ventilated intensive care unit patients is feasible. Treatment with antipsychotics in this limited pilot trial did not improve the number of days alive without delirium or coma, nor did it increase adverse outcomes. Thus, a large trial is needed to determine whether use of antipsychotics for intensive care unit delirium is appropriate.