ICU stay often causes long-term brain impairment, study finds
NEW YORK — Critically ill people who end up spending days in an intensive care unit often develop thinking and memory problems, according to a study.
Even when people recover from their physical illness, those problems can persist for more than a year after their hospital stay, researchers said.
They found ICU patients who were delirious — severely confused and unable to focus — were especially likely to go on to have thinking and memory problems.
“The longer you are delirious, the more likely you are to have long-term cognitive impairment that looks like Alzheimer's disease or traumatic brain injury,” said Dr. Wes Ely of the Vanderbilt University Medical Center in Nashville.
“For a long time, we thought delirium was just something that happened because people were in the ICU and that as soon as they got out of the ICU, they would be OK,” said Dr. Karin Neufeld, a psychiatrist at Johns Hopkins University School of Medicine in Baltimore.
Doctors are realizing that being delirious could be a sign that a patient is more severely ill.
“We need to redouble our efforts to reduce the number of days people are delirious and prevent it if we can,” said Neufeld, who was unconnected with the research.
Doctors have known for years that certain patients are prone to some degree of thinking problems after hospital procedures.
What is new about this study is that cognitive problems were seen among patients with a wide range of illnesses, Neufeld said. However, she added, the people were alike in one way: They were all very sick.
Ely and his team studied 821 people who ended up in the ICU because of respiratory failure or shock.
Those patients were originally hospitalized for infections or lung or stomach problems. None were hospitalized for brain-related issues such as strokes.
Nearly three-quarters of the patients became delirious during their ICU stay, typically for a few days at a time.
Three months after leaving the hospital, 40 percent of them had thinking problems comparable with someone with moderate traumatic brain injury, the researchers found. And 26 percent had cognitive scores as low as someone with mild Alzheimer's disease.
At the one-year mark, 34 percent of patients were functioning on the same level as someone with moderate traumatic brain injury and 24 percent at the level of a person with mild Alzheimer's.
“Your odds are not great in terms of recovery,” Ely said. “Some will recover, but most won't, and that is scary.”
The longer patients had been delirious in the ICU, the worse their thinking problems tended to be months after discharge, the researchers reported in The New England Journal of Medicine.
“Perhaps the scariest piece is that 30- and 40-year-olds coming in with no disease are often leaving with profound cognitive impairment,” Ely said in a statement.
Neufeld said keeping ICU patients pain-free but away from sedatives as much as possible and getting those who are able to walk around can lessen delirium.