Occurrence, causes, and outcome of delirium in patients with advanced cancer: a prospective study

Delirium impedes communication and contributes to symptom distress in patients with advanced cancer. There are few prospective data on the reversal of delirium in this population.

To evaluate the occurrence, precipitating factors, and reversibility of delirium in patients with advanced cancer.

Prospective serial assessment in a consecutive cohort of 113 patients with advanced cancer. Precipitating factors were examined using standardized criteria; 104 patients met eligibility criteria.

Acute palliative care unit in a university-affiliated teaching hospital.

Delirium occurrence and reversal rates, duration, and patient survival. Strengths of association of various precipitating factors with reversal were expressed as hazard ratios (HRs) in univariate and multivariate analyses.

On admission, delirium was diagnosed in 44 patients (42%), and of the remaining 60, delirium developed in 27 (45%). Reversal of delirium occurred in 46 (49%) of 94 episodes in 71 patients. Terminal delirium occurred in 46 (88%) of the 52 deaths. In univariate analysis, psychoactive medications, 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 reversibility. Hypoxic encephalopathy (HR, 0.39; 95% CI, 0.19-0.80) and metabolic factors (HR, 0.44; 95% CI, 0.21-0.91) were associated with nonreversibility. 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 associations. Patients with delirium had poorer survival rates than controls (P<.001).

Delirium is a frequent, multifactorial complication in advanced cancer. Despite its terminal presentation in most patients, delirium is reversible in approximately 50% of episodes. Delirium precipitated by opioids and other psychoactive medications and dehydration is frequently reversible with change of opioid or dose reduction, discontinuation of unnecessary psychoactive medication, or hydration, respectively.