Outcome, demography and resource utilization in ICU Patients with delirium and malignancy

Delirium in the general intensive care unit (ICU) population is common, associated with adverse outcomes and well studied. However, knowledge on delirium in the increasing number of ICU patients with malignancy is scarce. The aim was to assess the frequency of delirium and its impact on resource utilizations and outcomes in ICU patients with malignancy. This retrospective, single-center longitudinal cohort study included all patients with malignancy admitted to ICUs of a University Hospital during one year. Delirium was diagnosed by an Intensive Care Delirium Screening Checklist (ICDSC) score ≥ 4. Of 488 ICU patients with malignancy, 176/488 (36%) developed delirium. Delirious patients were older (66 [55-72] vs. 61 [51-69] years, p = 0.001), had higher SAPS II (41 [27-68] vs. 24 [17-32], p < 0.001) and more frequently sepsis (26/176 [15%] vs. 6/312 [1.9%], p < 0.001) and/or shock (30/176 [6.1%] vs. 6/312 [1.9%], p < 0.001). In multivariate analysis, delirium was independently associated with lower discharge home (OR [95% CI] 0.37 [0.24-0.57], p < 0.001), longer ICU (HR [95% CI] 0.30 [0.23-0.37], p < 0.001) and hospital length of stay (HR [95% CI] 0.62 [0.50-0.77], p < 0.001), longer mechanical ventilation (HR [95% CI] 0.40 [0.28-0.57], p < 0.001), higher ICU nursing workload (B [95% CI] 1.92 [1.67-2.21], p < 0.001) and ICU (B [95% CI] 2.08 [1.81-2.38], p < 0.001) and total costs (B [95% CI] 1.44 [1.30-1.60], p < 0.001). However, delirium was not independently associated with in-hospital mortality (OR [95% CI] 2.26 [0.93-5.54], p = 0.074). In conclusion, delirium was a frequent complication in ICU patients with malignancy independently associated with high resource utilizations, however, it was not independently associated with in-hospital mortality.