Delirium in older patients in surgical intensive care units.

PURPOSE: To examine the frequency and course of delirium in older adults admitted to a surgical intensive care unit (SICU).

DESIGN AND METHODS: Prospective, observational cohort study of 114 English-speaking participants and their surrogates, aged 65 and older, admitted to an SICU, and managed by a surgical critical care service. Chart reviews and surrogate interviews were conducted within 24 hours of SICU admission to collect information regarding evidence of dementia using the short form of the Informant Questionnaire on Cognitive Decline in the Elderly. Participants were also screened for delirium daily throughout their hospitalization with either the Confusion Assessment Method-ICU (CAM-ICU) while in the SICU or the CAM while on medical/surgical units.

RESULTS: In this population of older adults, 18.4% had evidence of dementia on admission to the SICU. Few older adults (2.6%) were admitted to the hospital with evidence of preexisting delirium, but 28.3% developed delirium in the SICU and 22.7% during the post-SICU period. A total of 52 of 114 (45.6%) participants were delirious sometime during their hospital stay or 24 hours before hospital admission. Episodes of deep sedation and nonarousal were uncommon, occurring in only 9.7% of the sample.

CONCLUSIONS: Older adults admitted to SICUs were at high risk for developing delirium during hospitalization. Further research is needed to elucidate the risk factors for, and outcomes of, delirium in this uniquely vulnerable population.