Severe sepsis in older patients was independently associated with substantial and persistent new cognitive impairment and functional disability among survivors.
Older adults who survive severe sepsis were more likely to develop substantial cognitive impairment and functional disability, according to data published in the October 27 JAMA.
“Cognitive and functional declines of the magnitude seen after severe sepsis are associated with significant increases in caregiver time, nursing home placement, depression, and mortality. [Our] data argue that the burden of sepsis survivorship is a substantial, underrecognized public health problem with major implications for patients, families, and the health care system,” said Theodore J. Iwashyna, MD, PhD, of the University of Michigan Medical School, Ann Arbor, and colleagues.
The researchers examined whether an episode of severe sepsis increased the odds of subsequent worsened cognitive impairment and functional disability among survivors. Their study involved 1,194 patients (average age at hospitalization, 76.9) with 1,520 hospitalizations for severe sepsis between 1998 and 2006. The study cohort was drawn from the larger Health and Retirement Study, a population-based survey of US residents. A total of 9,223 respondents had a cognitive functional assessment at the beginning of the study and also had linked Medicare claims; 516 survived severe sepsis and 4,517 survived a nonsepsis hospitalization to at least one follow-up survey and were included in the final analysis. Cognitive impairment was assessed, as was the number of activities of daily living (ADL) and instrumental ADLs (IADLs) for which patients needed assistance.
The researchers found that the prevalence of moderate to severe cognitive impairment increased 10.6% among patients who survived severe sepsis, and their odds of acquiring moderate to severe cognitive impairment were 3.3 times higher. Also, a high rate of new functional limitations was seen following sepsis, with an additional average increase of 1.5 new functional limitations per person among those with no mild to moderate pre-existing functional limitations. Nonsepsis general hospitalizations were associated with no change in moderate to severe cognitive impairment and with the development of fewer new limitations.
Dr. Iwashyna and colleagues commented that given published dementia and sepsis incidence rates for those 65 and older in the United States, their results suggest that nearly 20,000 new cases per year of moderate to severe cognitive impairment in the elderly may be attributable to sepsis. “Thus, an episode of severe sepsis, even when survived, may represent a sentinel event in the lives of patients and their families, resulting in new and often persistent disability, in some cases resembling dementia.”
A Hidden Health Disaster?
In an accompanying editorial, Derek C. Angus, MD, MPH, from the University of Pittsburgh School of Medicine, commented that the information provided by this study can help physicians when assessing care options and discussing outcomes with patients and families. Also, the development of preclinical models could help establish a better understanding of causality, potential mechanisms, and therapeutic targets. He also suggested that a number of relatively simple strategies used in other areas of medicine to promote physical rehabilitation and minimize cognitive dysfunction could potentially be adapted to the ICU and post-ICU setting. Finally, Dr. Angus suggested that the traditional end point of 28-day mortality in most trials of sepsis therapies should be replaced with longer-term survival data and functional outcomes.
—Glenn S. Williams