Occurrence, causes, and outcome of delirium in patients with advanced cancer - A prospective study

Context: Delirium impedes communication and contributes to symptom distress in patients with advanced cancer. There are few prospective data on the re versal of delirium in this population. Objectives: To evaluate the occurrence, precipitating factors, and reversib ility of delirium in patients with advanced cancer. Design: Prospective serial assessment in a consecutive cohort of 113 patien ts with advanced cancer. Precipitating factors were examined using standard ized criteria; 104 patients met eligibility criteria. Setting: Acute palliative care unit in a university-affiliated teaching hos pital. Main Outcome Measures: Delirium occurrence and reversal rates, duration, an d patient survival. Strengths of association of various precipitating facto rs with reversal were expressed as hazard ratios (HRs) in univariate and mu ltivariate analyses. Results: On admission, delirium was diagnosed in 44 patients (42%), and of the remaining 60, delirium developed in 27 (45%). Reversal of delirium occu rred in 46 (49%) of 94 episodes in 71 patients. Terminal delirium occurred in 46 (88%) of the 52 deaths. In univariate analysis, psychoactive medicati ons, predominantly opioids (HR, 8.85; 95% confidence interval [CI], 2.13-36 .74), and dehydration (HR, 2.35; 95% CI, 1.20-4.62) were associated with re versibility. Hypoxic encephalopathy (HR, 0.39; 95% CI, 0.19-0.80) and metab olic factors (HR, 0.44; 95% CI, 0.21-0.91) were associated with nonreversib ility. In mulitivariate analysis, psychoactive medications (HR, 6.65; 95%; CI, 1.49-29.62), hypoxic encephalopathy (HR, 0.32; 95% CI, 0.15-0.70), and nonrespiratory infection (HR, 0.23; 95% CI, 0.08-0.64) had independent asso ciations. Patients with delirium had poorer survival rates than controls (P < .001). Conclusions: Delirium is a frequent, multifactorial complication in advance d cancer. Despite its terminal presentation in most patients, delirium is r eversible in approximately 50% of episodes. Delirium precipitated by opioid s and other psychoactive medications and dehydration is frequently reversib le with change of opioid or dose reduction, discontinuation of unnecessary psychoactive medication, or hydration, respectively.