Sepsis a 'Hidden Public Health Disaster'

Other areas that posed additional problems included dressing, eating, using the telephone, managing money, taking medications, or getting into bed. "There was wide range of new difficulties across the array of activities," the authors wrote.

The authors did not say definitively what mechanism deteriorates function or cognition, but they hypothesized some pathways:

• There could be a direct inflammatory and hypoperfusion mediated degradation of muscle fibers and neurons for patients who have been hospitalized in the intensive care unit.
• Hypotension or hypoperfusion may directly contribute to brain injury
• Inflammation, a byproduct of sepsis' pathophysiology, could provoke vascular dementia and Alzheimer's disease.
• Delirium, common in sepsis, is associated with cognitive decline and long-term cognitive impairment in patients treated with mechanical ventilation.

The authors also discussed the cost to society.

"Cognitive and functional declines of the magnitude seen after severe sepsis are associated with significant increases in caregiver time, nursing home admission, depression, and mortality," they wrote. "These data argue that the burden of sepsis survivorship is a substantial, under recognized public health problem with major implications for patients, families and the healthcare system." 

They added that patients with this severe cognitive impairment "[have] been associated with an additional 40 hours per week of informal care provided by families, analogous to an additional fulltime job."

Iwashyna and colleagues called sepsis "a sentinel event" and said that future research to identify mechanisms leading from sepsis to cognitive impairment and functional disability, as well as interventions to prevent or slow the process, "is especially important now given the aging of the population."