A new US study found that older patients who survived severe sepsis were more likely to experience signficant mental and physical decline, in some cases not unlike dementia, and suggested this was an unrecognized public health problem with major implications not only for patients but also for families and healthcare providers.
You can read how first author Dr Theodore J Iwashyna, assistant professor of internal medicine at the University of Michigan Medical School, Ann Arbor, and colleagues arrived at these findings in the 27 October issue of JAMA.
Sepsis is a severe condition that affects the whole body and occurs when the bloodstream is overwhelmed by bacteria: it can result in failure of multiple organ systems. The infection can start anywhere in the body, the more common places being the bowel, kidneys, liver, gall bladder, lungs or skin. About 40 per cent of people with severe sepsis die from it.
Although anyone can get sepsis, older people and those with weak immune systems are the most susceptible. Every year, hundreds of thousands of Americans survive sepsis, and researchers believe the numbers are rising.
Sepsis is the most common non-cardiac cause of critical illness, but we don’t know much about its long term mental and physical effects, wrote the authors, who decided to investigate whether surviving an episode of severe sepsis increased older people’s odds of mental and physical decline.
For the study, Iwashyna and colleagues reviewed data on 1194 patients with 1520 hospitalizations for severe sepsis drawn from the Health and Retirement Study, a nationally representative survey that followed US residents from 1998 to 2006.
From those records they found a total of 9223 patients who had undergone an assessment of cognitive and physical functioning at the start of the study period, and for whom they could access their Medicare claims.
Of these patients, 516 had survived severe sepsis (their average age was 76.9 when in hospital), and a further 4517 had also been hospitalized but did not have sepsis, and all took part in at least one follow-up survey, which included assessments of cognitive impairment and the number of activities of daily living (ADLs), and activities where they also needed help (“instrumental ADLs” or “IADLs”).
The researchers found that 60 per cent of of hospitalizations for severe sepsis were linked with worsened cognitive and physical function among surviving older adults.
They calculated the odds of acquiring moderate to severe cognitive impairment to be 3.3 times higher among sepsis survivors compared with counterparts who had also been hospitalized but not for sepsis.
In terms of physical impairment, the researchers found a high level of “new functional limitations” among the sepsis survivors: on average this equated to 1.5 new limitations per patient who previously either had no limitations or only mild to moderate limitations.
For example, among patients who had no limitations before they had sepsis, more than 40 per cent developed problems with walking, and nearly 1 in 5 experienced new difficulties with shopping or preparing a meal. Patients also developed new problems in basic areas of daily functioning like bathing themselves and going to the toilet on their own.
In contrast, there was no link in the non-sepsis group between hospitalization and change in moderate to severe cognitive impairment, and although hospitalization was linked with new limitations, these were fewer than in the sepsis group.
Iwashyna told the media that:
“We used to think of sepsis as just a medical emergency, an infection that you get sick with and then recover.”
“But we discovered a significant number of people face years of problems afterwards,” he added, explaining that these problems are “bigger and more common than we expected”.
“Most older Americans suffer real brain and body problems. We need new treatments, not just for the sepsis infection, but to prevent these new disabilities afterwards,” urged Iwashyna.
These findings show that most older patients who survive sepsis suffer with life-changing burdens, said Iwashyna.
“This is an underrecognized public health problem with major implications for patients, families and the health care system,” he added, explaining that we need to make sure families get the help they need to care for sepsis survivors when they come out of hospital.
“It’s not enough just to get them through the acute episode. We need to start preparing them for the years of problems they may have afterwards,” said Iwashyna.
One way to decrease risk of infection is to make sure older people get their flu and pneumonia vaccines, said co-author Dr Kenneth M. Langa, a professor of internal medicine at the University of Michigan.
“Physicians need to be aware of the long-term risk for cognitive and physical disabilities that many patients may face,” he added.
Langa, who is also a core investigator for the Ann Arbor Veterans Administration Health Services Research and Development Service’s Center of Excellence, said that unlike Alzheimer’s and other types of dementia, the cognitive impairment that follows sepsis is likely to be at least partly preventable, and to do this we need better acute care of the sepsis episode and improved rehab once the patient leaves hospital.
“This research underscores the need for physicians who care for older adults to focus early on preventing infections that can lead to sepsis,” he added.
Iwashyna said “we need to start working early”, from when the sepsis patients come into hospital, so they don’t develop new disabilities.
In an editorial accompanying the study, Dr Derek C. Angus, of the University of Pittsburgh School of Medicine, and Contributing Editor of JAMA, wrote that the study raises several important points.
First, the findings can help doctors assess care options and discuss them with patients and their families. Second, it should help the development of better models and ways of understanding sepsis, since currently these are limited to what happens in the ICU and rarely take into account long-term outcomes.
Third, we can borrow and adapt from a number of relatively simple approaches used in other areas of medicine to improve physical rehab and minimize the effect of mental dysfunction, and these could be evaluated in clinical trials. And fourth, the current narrow mortality measurement used in evaluating therapies for sepsis, which is limited to an end point of 28 days, should be replaced by a measure of long term survival coupled with functional outcomes.
“Assessing detailed physical and cognitive function is challenging and costly in the multicenter trial environment. However, the larger cost may be from failure to measure these outcomes and miss important benefits or harms of therapies on the lingering consequences of sepsis,” wrote Angus.
Funds from the National Institute on Aging and the National Heart, Lung and Blood Institute helped pay for the study.
“Long-term Cognitive Impairment and Functional Disability Among Survivors of Severe Sepsis.”
Theodore J. Iwashyna; E. Wesley Ely; Dylan M. Smith; Kenneth M. Langa.
DOI:10.1001/jama.2010.1553
Additional sources: University of Michigan Health System, JAMA and Archives Journals, MedLine Plus.
Written by: Catharine Paddock, PhD