50+: Live Better, Longer

Sepsis Linked to Dementia in Elderly

Long-Term Impact of Sepsis

The study included older people enrolled in a larger, nationally representative ongoing health study that included periodic assessment of mental functioning. About 1,500 episodes of severe sepsis occurred among the enrollees between 1998 and 2005, and about 40% of these episodes ended in death within 90 days.

Researchers compared outcomes among 516 people who survived sepsis to 4,517 people who survived a non-sepsis related hospitalization during about the same period. The average age of the survivors in both groups during hospitalization was 77.

Close to 60% of the hospitalizations for severe sepsis were associated with worsened mental and physical function, or both, in the years following the event.

Moderate to severe cognitive impairment almost tripled in the sepsis survivors, from 6% before sepsis to almost 17% after.

“Among people with no mental or physical limitations before sepsis, around 40% could not walk without assistance in the years after,” Iwashyna says.

Vaccination Prevents Sepsis

The findings highlight the importance of preventing sepsis in older patients, Iwashyna and Angus say.

One of the best strategies for doing this is to vaccinate vulnerable elderly populations against diseases like flu and pneumonia.

Studies are also needed to determine if ICU practices contribute to the long-term problems identified in the study, Iwashyna says.

“We know that a core part of sepsis is delirium and that delirium is associated with progression of Alzheimer’s disease and cognitive decline,” he says. “It may be that preventing delirium in the ICU could have real benefits later on.”

Treatments designed to reduce inflammation may also affect long-term outcomes, Angus says.

“Inflammation has been implicated in all kinds of health issues, including cognitive decline, and it is a hallmark of severe sepsis,” he says. “Sepsis causes a huge inflammatory response, and we don’t know what the long-term impact is.”