Additionally, he says, "one in four patients had scores very similar to what would be seen in patients with Alzheimer's disease."
The researchers then looked at what factors provoked the loss of mental function in these patients. They found that the longer a patient endured an episode of delirium in the ICU, measured by altered levels of consciousness, inattention, and disorganized thinking—a relatively common occurrence during extended hospitalization—the more likely the patient was to have a significant decline in ability to think, a correlation noted up to a year after patients were discharged.
"The cause of their loss of cognitive function was definitely not what brought them into the ICU," Pandharipande, says.
That may be good news in a way, Pandharipande says, "because there are many ways we think we can reduce delirium," as some hospital protocols are beginning to show.
For example, when patients need sedation, light sedatives can be used instead of heavier drugs like benzodiazepines. Patients can be prompted to be kept awake, alert, and interactive. And when they are supposed to go to sleep, they can be left alone to sleep instead of being awakened repeatedly for tests or to be checked on.
"If there are times during hospitalization when patients are not as critically ill, we can consider letting them sleep, turn[ing] off monitors beeping in their bedrooms, and not [giving] patients baths at 2 a.m. just because it's convenient for the healthcare team," Pandharipande says.