July 8, 2021

Delirium and mortality reexamined

A multicenter study of ICU patients found that in the hospital, delirium was associated with a nearly three-fold increase in risk of death the following day, but after discharge there was no association between delirium and mortality.

Studies in critical care settings have produced somewhat inconsistent findings regarding delirium and mortality. For a fresh look, Christopher Hughes, MD, MS, Mayur Patel, MD, MPH, and colleagues conducted a secondary analysis of a multicenter study in which ICU patients with respiratory failure or shock, or both, had received twice-daily delirium assessments.

Appearing in Anesthesia & Analgesia, the new study is based on 1,040 patients seen at five health systems from 2007 to 2010, 21% of whom died in the hospital, an additional 20% dying within a year. 

Occurrences of delirium had been categorized according to two psychomotoric subtypes, with some individuals exhibiting contrasting subtypes in consecutive evaluations. Delirium occurred in 71% of enrolled patients. 

In the hospital, delirium was associated with a nearly three-fold increase in the risk of death the following day, with the hypoactive subtype especially implicated. Over the first year after discharge, neither delirium presence nor delirium duration were associated with mortality.

Also on the study from Vanderbilt University Medical Center were Christina Hayhurst, MD, Pratik Pandharipande, MD, MSCI, Matthew Shotwell, PhD, Xiaoke Feng, MS, Jo Ellen Wilson, MD, MPH, James Jackson, PsyD, and Wesley Ely, MD, MPH. They were joined by researchers from Ohio State University and the University of Pittsburgh. The study was supported in part by the National Institutes of Health (AG027472, AG045085).